Del Mar Photonics - Newsletter Fall 2010 - Newsletter Winter 2010

40th EGAS Conference

Technische Universität Graz

Institut für Experimentalphysik

2 - 5 July 2008

European

Group for

Atomic

Systems

ABSTRACTS

Editor: L. Windholz

ORGANIZING COMMITTEE:

W.E. Ernst (Vice Chairman), T. Neger, G. Pottlacher, L. Windholz (Chairman)

CONTACT ADDRESS:

Institut für Experimentalphysik, Technische Universität Graz,

Petersgasse 16, A-8010 Graz

Tel. ++43 316 873 8144 (8141), Fax ++43 316 873 8655

e-mail: windholz@tugraz.at

This volume is published under the copyright of the European Physical Society

(EPS). We want to inform the authors that the transfer of the copyright to EPS
should

not prevent an author to publish an article in a journal quoting the original
first

publication or to use the same abstract for another conference. This copyright
is just

to prevent EPS against using the same material in similar publications.

The EGAS logo shows the hyperfine pattern of a Pr I line in which the
intensities of the

components does not follow the theoretically predicted rules.

II

The 40th EGAS Conference is sponsored by

Bundesministerium für

Wissenschaft und Forschung

http://www.bmwf.gv.at

Landeshauptmann Mag. Franz

Voves

Landesrätin Mag. Kristina Edlinger-

Ploder

http://www.graz.at/EN

Technische Universität Graz

http://www.tugraz.at

TOPTICA Photonics AG

http://www.toptica.com

Springer-Verlag GmbH

http://www.springer.com

piezosystem jena GmbH

http://www.piezojena.com/

Coherent (Deutschland) GmbH

http://www.coherent.de/

III

Pfeiffer Vacuum GmbH

http://www.pfeiffer-vacuum.de/

Kurt J. Lesker Company GmbH

http://www.lesker.com/

Radiant Dyes Laser & Accessories

GmbH

http://www.radiant-dyes.com/

iseg Spezialelektronik GmbH

http://www.iseg-hv.de/

ILMVAC GmbH

http://www.ilmvac.de/

Journal of Physics B: Atomic,

Molecular and Optical Physics

http://www.iop.org/journals/jphysb

MEWASA FLEX GmbH

http://www.mewasaflex.de/

Bernhard Halle Nachfl. GmbH

http://www.b-halle.de/

IV

Members of the board of the EUROPEAN GROUP FOR ATOMIC SYSTEMS

Prof. Hartmut HOTOP , CHAIR

Fachbereich Physik, Universität

Kaiserslautern

Postfach 3049

D-67653 KAISERSLAUTERN, Germany

Tel.: +49-631-205-2328

Fax: +49-631-205-3906

E-mail: hotop@physik.uni-kl.de

Prof. Frédéric MERKT (SECRETARY)

Laboratorium für Physikalische Chemie

ETH Zurich, HCI Hönggerberg

CH-8093 ZURICH, Switzerland

Tel.: +41-44 632 4367

Fax.: +41-44 632 1021

E-mail : frederic.merkt@ethz.ch

Dr. Christian BORDAS

Laboratoire de spectrométrie ionique et

moléculaire (LASIM)

université Lyon I bâtiment Kastler

43, boulevard du 11-Novembre 1918

F 69622 VILLEURBANNE, France

Tel. : +33 4 7243 1086

Fax : +33 4 7243 1507

E-mail : bordas@lasim.univ-lyon1.fr

Prof. Mike CHARLTON

Department of Physics

University of Wales Swansea

Singleton Park

SWANSEA SA2 8PP, United Kingdom

Tel. : +44 (0)1792 295 372

Fax : +44 (0)1792 295 324

E-mail : M.Charlton@swansea.ac.uk

Prof. Michael DREWSEN

Departement of Physics and Astronomy

University of Aarhus

NY Munkegade, BYG.520

DK-8000 AARHUS, Denmark

Tel.: +45 8942 3752

Fax.: +45 8612 0740

E-mail : drewsen@phys.au.dk

Prof. Wolfgang E. ERNST

Institute of Experimental Physics

Graz University of Technology

Petergasse 16

A-8010 GRAZ, Austria

Tel. : +43 316 873 8140

Fax : +43 316 873 8655

E-mail : wolfgang.ernst@tugraz.at

Prof. Jürgen ESCHNER

ICFO, Institute of Quantum Optics

Jordi Girona 29, Nexus II

08034 BARCELONA, Spain

Tel: +34-933964695

Fax: +34-934137943

E-mail : Juergen.Eschner@icfo.es

Prof. Nikolay KABACHNIK

Department of physics

Moscow State University,

Leninskiz Gory, Moscow 119992,

Russia

Tel. +7 495 939 3605

Fax +7 495 939 0896

E-mail : nkabach@mail.ru

V

Prof. Eva LINDROTH

Atomic Physics, Fysikum

Stockholm University

AlbaNova University Centre

SE-106 91 STOCKHOLM, Sweden

Tel.: +46-8 5537 8616

Fax.: +46-8 5537 8601

E-mail : lindroth@physto.se

Prof. Krzysztof PACHUCKI

Institute of Theoretical Physics

Warsaw University

Ul. Hoza 69

PL - 00-681 WARSAW, Poland

Tel.: +48-22-5532246

Fax: +48-22-6219475

E-mail: Krzysztof.Pachucki@fuw.edu.pl

Prof. Antonio SASSO

Università di Napoli Federico II

Dipartemento di Scienze Fisiche

Complesso Universitario Monte S.

Angelo

Via Cinthia, I-801236 NAPOLI, Italia

Tel. +39 081 67 6120 / 6273

Fax +39 081 67 6346

E-mail: sasso@na.infn.it

Prof. Kenneth TAYLOR

Department of applied mathematics and

theoretical physics

Queen's University of Belfast

BELFAST BT7 1NN, Northern Ireland,

UK

Tel. : 028 9033 5049

Fax : 028 9023 9182

E-mail : k.taylor@qub.ac.uk

Prof. Nikolay V. VITANOV

Department of Physics,

Sofia university

James Bourchier 5 Blvd.

Tel. +359 2 8161 652

Fax +359 2 9625 276

E-mail: vitanov@phys.uni-sofia.bg

Prof. Marc J.J. VRAKKING

AMOLF-FOM

Institute for Atomic and molecular

Physics

Kruislaan 407

1098 SJ AMSTERDAM, The

Netherlands

Tel. ?

Fax +31 20 6684106

E-mail: vrakking@amolf.nl

Webmaster

Prof. Henri-Pierre GARNIR

Université de Liège

IPNAS, Sart Tilman B15

B-4000 LIEGE, belgium

Tel. +32 4 366 3764

Fax +32 4 366 2884

E-mail: hpgarnir@ulg.ac.be

VI

Contents

This book contains all abstracts arrived in Graz before June 15, 2008

VII

VIII

A Brief History of Elemental Carbon

R.F. Curl, jr.

University Professor Emeritus, Pitzer-Schlumberger Professor of Natural Sciences

Emeritus, Professor of Chemisty Emeritus, Departement of Chemistry, Rice
University,

Houston, Texas, U.S.A., rfcurl@rice.edu

Carbon is the only element that humanity has routinely been in contact with in
reasonably

pure form since the origin of the species. With this much experience with it,
one might

think that the chemistry of pure carbon is completely understood and developed.
Nothing

could be further from the real situation. Although many important advances have
been

made recently, there is much that is not understood and probably much to be
discovered

about the chemistry and uses of this extremely flexible element. This talk will
be a rapid

survey of human experience with elemental carbon and the variety of forms it can
take.

EL 1

1

Non-demolition photon counting and field quantum

state reconstruction in a cavity: a new way to look at

light

Serge Haroche

ENS and Collège de France, Paris

While usual photo-detection destroys light quanta, we have developed a quantum
nondemolition

way to count photons trapped in a cavity without absorbing them, making

it possible to measure the same field repeatedly. We use as detectors atoms
prepared in

Rydberg states which cross the cavity one at a time and behave as microscopic
clocks

whose ticking rate is affected by light. By measuring the clocks delay,
information is

extracted without energy absorption and the field progressively collapses into a
welldefined

photon number state. Quantum jumps between decreasing photon numbers are

recorded as the cavity field subsequently relaxes towards vacuum. This new way
to

look at light can also generate coherent superpositions of photonic states with
different

phases called "Schrödinger cats". By exploiting information provided by
sequences of

atoms crossing the cavity and interacting non-destructively with its field, we
reconstruct

these Schrödinger cat states which are represented in phase space by Wigner
functions

exhibiting striking non-classical features. We directly monitor in this way the
process

of decoherence in experiments opening new avenues for the exploration of the
boundary

between the quantum and classical worlds.

PL 1

2

Theory and Spectroscopy of Parity Violation in

Chiral Molecules

Martin Quack

ETH ZÄurich, Laboratorium fÄur Physikalische Chemie, Wolfgang-Pauli-Str. 10,

CH-8093 ZÄurich,

web: www.ir.ethz.ch; email: Martin@Quack.ch

Parity violation plays a crucial role in the Standard Model of Particle Physics
and ac-

cording to current understanding it has crucial connections to fundamental
symmetry

violations in general and to such fundamental phenomena as the existence of mass
of the

elementary particles (see [1,2]) and references cited therein). In chemistry,
one important

consequence is a \parity violating energy diŽerence"¢PV E of the ground state
energies of

enantiomers of chiral molecules, corresponding to a non zero enthalpy of
stereomutation

or enantiomerisation ¢RH0

0 = NA¢PV E, which would be exactly zero if perfect inversion

symmetry were true. An experiment to measure this very small energy diŽerence in
the

sub-femto-eV (or atto-eV) range, typically, has been proposed some time ago [3].
Recent

improved theory [4,5,6] predicts parity violating potentials to be larger by
about two or-

ders of magnitude for the prototype compound H2O2 and related molecules, as
compared

to older theories, and this large increase has been con¯rmed by subsequent
independent

theoretical results in several groups. Thus the prospects for successful
experiments look

brighter today than ever before [7].

In the lecture we will discuss the current status of the ¯eld and report in some
detail on

the various spectroscopic approaches, which can be used, as well as the current
challenges

of these experiments [7]. If time permits, even more fundamental symmetry
violations

such as CP and CPT violation will be discussed [1,8].

References

[1] M. Quack, in \Modelling Molecular Structure and Reactivity in Biological
Sys-

tems", Proc. 7th WATOC Congress, Cape Town January 2005 (Eds.: K. J. Naidoo,

J. Brady, M. J. Field, J. Gao, M. Hann), Royal Society of Chemistry, Cambridge

(2006), ISBN 0-85404-668-2, pages 3 - 38

[2] M. Quack, Nova Acta Leopoldina 81, 137 (1999), (earlier version of [1], in
German).

[3] M. Quack, Chem. Phys. Lett. 132, 147 (1986); M. Quack, Angew. Chem. Int. Ed.

(Engl.) 28, 571 (1989).

[4] A. Bakasov, T. K. Ha, M. Quack, in \Chemical Evolution, Physics of the
Origin

and Evolution of Life ", Proc. of the 4th Trieste Conference (1995) (Eds.: J.
Chela-

Flores, F. Raulin), Kluwer Academic Publishers, Dordrecht (1996), ISBN 0-7923-

4111-2, pages 287-296.

[5] A. Bakasov, T. K. Ha, M. Quack, J. Chem. Phys. 109, 7263 (1998).

[6] R. Berger, M. Quack, J. Chem. Phys. 112, 3148 (2000).

[7] M. Quack, J. Stohner, M. Willeke, Annu. Rev. Phys. Chem. 59, 741 (2008).

[8] M. Quack, Paper at EGAS Conference 2 to 5 July (2008)

PL 2

3

Precision Experiments with Highly Charged Ions

H.-Jurgen Kluge for the HITRAP Collaboration

GSI/Darmstadt and University of Heidelberg, Germany

Highly-charged ions (HCI) con ned in Penning traps and storage rings have been
applied

for high-precision experiments such as mass spectrometry or x-ray, laser and
radiofrequency

spectroscopy. Storage and cooling of HCI in trapping devices are prerequisites

for such high-accuracy experiments in which even a single stored particle can be
observed.

In the case of a radioactive ion, the fate of an individual ion, undergoing a
nuclear decay,

can be studied in detail by observing the disappearance of the signal of the
mother and

the appearance of that of the daughter isotope. Since the mass resolving power
of mass

spectrometry using Penning traps or storage rings increases with the charge
state, charge

breeding and the use of HCI is planned for quite a number of radioactive beam
facilities.

Few-electron ions are simple systems which are calculable by theory with high
accuracy.

In such systems, the electric eld strength increases roughly with the third
power of the

nuclear charge and reaches values much larger than presently achievable with the
most

powerful short-pulse lasers. These HCI up to hydrogen-like U91+ are testing
grounds for

QED in the little explored regime of extreme electromagnetic elds.

In order to increase the accuracy further for investigating simple systems, the
Highlycharged

Ion TRAP (HITRAP) facility is presently being built up at GSI. Stable or
radioactive

HCI are produced by stripping relativistic ions in a target and injecting them

into the storage ring ESR at GSI. After electron cooling and deceleration to 4
MeV per

nucleon, these ions are ejected out of the storage ring, decelerated further in
a linear

decelerator, and injected into a Penning trap where a temperature of 4 K is
reached by

electron and resistive cooling. From here, the cooled HCI are transferred at low
energies

to experimental setups. A large number of unique experiments with very heavy
ions up

to hydrogen-like U91+ are being prepared by the international HITRAP
Collaboration:

Clean samples of stored and cooled HCI in a chosen speci c charge state can be

investigated by observation of x-rays from a quasi point-like source.

If the accuracy of QED calculations is improved, the ne structure constant can

be determined with high accuracy measuring the g-factor of the bound electron.

Mass measurements can be performed with extreme accuracy of better than 1011

and with single-ion sensitivity by using stored HCI.

A measurement and comparison of the nuclear g-factor of the bare nucleus with
that

of the neutral atom allows one to check calculations of the diamagnetic
correction

for the rst time.

The hyper ne structure of the ground state in hydrogen-like systems can be
determined.

Optical pumping of the M1 transition will result in electronic and nuclear

polarization enabling clean nuclear-decay experiments and, in this way,
sensitive

tests of weak interaction.

Recoil ion momentum spectroscopy, ion-surface interaction experiments, and
hollowatom

spectroscopy can be performed in a regime of extr. low energies using HCI.

PL 3

4

AtomChips:

Integrated circuits for matter waves

Jorg Schmiedmayer

Atominstitut der Osterreichischen Universitaten, TU-Wien

AtomChips [1] aim at the miniaturization and integration of quantum optics and
atomic

physics on to a single chip, analogous to electronic circuits. It combines the
best of both

worlds: The perfected manipulation techniques from atomic physics with the
capability

of nanofabrication. AtomChips promise to allow coherent manipulation of matter
waves

on the quantum level by using high spatial resolution electro magnetic
potentials from

structures on the atom chip or by employing adiabatic radio frequency (RF) or
micro

wave (MW) potentials.

The talk will give an overview of the recent advances in the concepts,
fabrication and

experimental realization of AtomChips by illustrating the many di erent tasks
that can

be performed using ultra cold or Bose-Einstein condensed (BECs) atoms
manipulated on

the chip. These range from measuring magnetic and electric elds with
unprecedented

sensitivity by observing the density modulations in trapped highly elongated 1d
BECs

[2], to fundamental studies of the universal properties in low dimensional
systems like non

equilibrium dynamics and coherence decay [3] or signatures of thermal and
quantum noise

[4] in one dimensional super uids. The talk will give an overview of the recent
advances

and experiments.

This work was supported by the European Union MC network AtomChips, integrated

project SCALA, the DIP the FWF and the Wittgenstein Prize.

[1] For an overview see: Microscopic atom optics: from wires to an atom chip.
Folman,

R., Krger, P., Schmiedmayer, J., Denschlag, J. Henkel,C., Adv. At. Mol. Opt.
Phys.

48, 263 (2002).

[2] St. Wildermuth et al. Nature 435, 440 (2005); S. Aigner et al. Science 319,
1226

(2008)

[3] Ho erberth et al. Nature 449, 324 (2007)

[4] Ho erberth et al. Nature Physics (2008), DOI:10.1038/nphys941;
arXiv:0710.1575

PL 4

5

Optical Atomic Clocks at the Frontiers of Metrology

Fritz Riehle

Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38 116 Braunschweig
Germany

Several optical atomic clocks are now beginning to outperform the best caesium
atomic

clocks that represent the realization of the definition of the unit of time in
the International

Systems of Units (SI). Consequently, four optical frequency standards have
recently been

selected and recommended as secondary representations of the second by the
International

Committee of Weights and Measures. Among them are the 171Yb+ frequency standard
at

688 THz which is based on an electric quadrupole transition of a single,
laser-cooled ion

held in a rf Paul trap and the 87Sr standard at 429 THz based on a cloud of
neutral atoms

in an optical lattice at the magic wavelength. Due to the large number of atoms
that can

be interrogated in parallel, neutral atom optical frequency standards and clocks
allow for

unprecedented high short-term stability as compared to single ion standards
whereas up

to now single-ion standards seem to have the best prospects for fractional
uncertainties

around 10−17 and below. In the talk the status of both standards at PTB and
elsewhere

will be reviewed.

Apart from possible future realizations of the second those optical clocks
clocks are used

to give upper limits for a possible drift of fundamental constants that is asked
for by a

certain class of theories that aim to combine quantum theory and General
Relativity.

The unprecedented high accuracies and stabilities of optical clocks require
novel solutions

for meaningful comparisons of remote optical clocks. A particular interesting,
novel

and challenging approach is to phase-coherently shift the frequency of a
particular optical

atomic clock to the 1.54 μm band by means of a femtosecond comb, to transfer

this frequency over an existing commercial telecommunication network and to
employ a

second frequency comb at the user end for comparison or calibration of the
optical frequency

standard at this place. First experimental results and planned realizations will
be

reported.

The remote comparison of optical clocks with fractional uncertainties around
10−18 is

extremely challenging. A frequency shift of this magnitude results e.g. from the
Doppler

effect already by a relative motion of a few micrometers per day or by the
gravitational

red shift due to a vertical height difference of 1 cm in the gravitational
potential near

the surface of the Earth. It can be expected that frequency stabilized lasers of
such high

accuracy apart from their use as precise clocks might be used as sensitive
probes for their

relativistic environment and for other novel applications.

PL 5

6

Alkali Atoms, Dimers, Exciplexes and Clusters

in 4He Crystals

A. Weis, P. Moroshkin, V. Lebedev, and A. Hofer

Physics Department, University of Fribourg, Chemin du Musśee 3, CH-1700 Fribourg

A closed-shell He atom and a single-electron alkali atom strongly repel each
other be-

cause of the Pauli principle. As a consequence, an alkali atom immersed into
condensed

(super°uid or solid) 4He forms a spherical bubble state, in which the alkali
repels the He

quantum °uid/solid by imposing its own symmetry on the local He environment. For
15

years we have investigated such atomic bubbles in solid 4He using optical and
magnetic

resonance spectroscopy.

In this talk I will ¯rst review our high resolution magnetic resonance studies
performed on

solid He matrix-isolated alkali atoms in the radio-frequency and microwave
domains with

special emphasis on their sensitive dependence on the crystalline structure
(body-centered

cubic, bcc, versus hexagonally close-packed, hcp) of the helium matrix.

In recent years we have extended the purely atomic studies to larger bound
complexes,

such as exciplexes, dimers and clusters. I will present some of our intriguing
recent results:

² In their respective ground states, alkali and He atoms are the worst enemies
in the

periodic table and strongly repel each other. Excited alkali atoms, however,
attract

He atoms and form bound states (so-called exciplexes), in which up to 7 He atoms

can be attached to one alkali atom.

² Cs2 and Rb2 dimers in solid He can be excited via a large variety of
absorption

bands, and the deexcitation proceeds either by photodissociation or by emission

of radiation. We made the strange observation that, irrespective of the
excitation

band, dimer °uorescence is only emitted on the (1)3Śu ! X 1§g triplet-singlet

transition which is forbidden in the free dimer.

² When the ¯rst excited P1=2 state of an alkali atom is populated by direct
atomic

excitation, it °uoresces at 879 nm (1.7% blueshifted from the free atomic
transition

at 894 nm), a quantitatively well explained fact. However, when the same state
is

populated by photodissociation of the dimer, the emission wavelength is 885 nm.

We attribute this eŽect to the formation of an entangled diatomic bubble state.

² The doped region of the He crystal has a bluish color that originates from Mie

scattering by alkali clusters, the size distribution of which can be inferred
from the

extinction spectrum.

² When the doped He crystal is molten by lowering the He pressure, the doped

(column-shaped) region remains solid at pressures, where pure He is super°uid.

We present experimental support for our hypothesis that this new form of solid
He

is an amorphous or crystalline ionic structure formed by snowballs (nanoscopic
solid

He structures formed around positive ions) and electron bubbles.

PL 6

7

Generation of Short Wavelength Radiation via

Coherent Hyper Raman Superradiance

Marlan O. Scully

Texas AM University and Princeton University

We nd that intense short pulses of XUV radiation can be produced by cooperative

spontaneous emission from visible or IR laser pulses driving atoms or ions. The
process

depends on the generation and utilization of atomic coherence as is the case in
lasing

without inversion. However, the radiation process is not stimulated emission,
but is

rather cooperative spontaneous emission in the since of Dicke. More precisely,
the many

atom mathematics of the problem is the same as that of coherent anti-Stokes
Raman

scattering.

PL 7

8

Cold Atom Interferometry

for Gravitational Experiments

G. M. Tino

Dipartimento di Fisica and LENS Laboratory - Università di Firenze

Istituto Nazionale di Fisica Nucleare, Sezione di Firenze

via Sansone 1, Polo Scientifico, I-50019 Sesto Fiorentino (Firenze), Italy

E-mail: guglielmo.tino@fi.infn.it

Experiments we are performing using atom interferometry to determine the

gravitational constant G [1] and test the Newtonian gravitational law at
micrometric

distances [2] will be presented. Other experiments in progress, planned or being

considered using atom interferometers in ground laboratories [3] and in space
[4] will be

also discussed.

References

1. G. Lamporesi, A. Bertoldi, L. Cacciapuoti, M. Prevedelli, and G. M. Tino,
Phys. Rev. Lett. 100, 050801,

(2008).

2. G. Ferrari, N. Poli, F. Sorrentino, and G. M. Tino, Phys. Rev. Lett. 97,
060402, (2006).

3. M. de Angelis, A. Bertoldi, L. Cacciapuoti, A. Giorgini, G. Lamporesi, M.
Prevedelli, G. Saccorotti, F.

Sorrentino, G.M. Tino, to be published.

4. G. M. Tino, L. Cacciapuoti, K. Bongs, Ch. J. Bordé, P. Bouyer, H. Dittus, W.
Ertmer, A. Görlitz,

M. Inguscio, A. Landragin, P. Lemonde, C. Lammerzahl, A. Peters, E. Rasel, J.
Reichel, C. Salomon,

S. Schiller, W. Schleich, K. Sengstock, U. Sterr, M. Wilkens, Nuclear Physics B
(PS) 166, 159, (2007).

PL 8

9

Photodetachment microscopy in a magnetic field

C. Blondel, W. Chaibi, C. Delsart and C. Drag

Laboratoire Aim´e-Cotton, Centre national de la recherche scientifique,

Univ. Paris-sud 11, bˆatiment 505, F-91405 Orsay, France

Among some remarkable properties of charged-particle interferometry, one has
known for

sixty years of the case where a perturbation can induce a shift of interference
fringes even

though no physical field acts on the classical particle trajectories [1,2]. In
such an extreme

case, of course, all trajectories remain unperturbed, and the fringes shift with
respect to

a motionless envelope.

Less attention was paid to the other extreme situation, where a uniform, e.g.
magnetic

field acts on all possible trajectories of the interferometer volume. In this
case, the Lorentz

force is expected to bend all trajectories, while the added magnetic flux is
expected to

change the interferometer phase. No doubt that, on a microscopic scale, the
latter (phase

shift) is the quantum-mechanical explanation of the former (trajectory shift).
Interferometers,

however, provide a situation where the added magnetic flux is no longer between

infinitesimally close trajectories, but between pairs of trajectories with a
macroscopic separation.

In the ordinary photodetachment microscopy situation [3], a μT is enough to

produce a 100 radian phase shift between trajectories of the most sensitive
pairs, which

is definitely beyond the perturbative regime.

A review of past interference experiments shows that the identity of fringe and
trajectory

shifts was actually seldom addressed. The well-known sensitivity of
interferometers to

external perturbations can even be misinterpreted as an argument for a greater
shift of

the interference fringes. On the other hand, analogy of the magnetic field
action to the

effect of rotation of the whole apparatus can serve as an argument for the
identity of

fringe and trajectory displacements. Rotation vs. magnetic field analogy is
however only

a first-order approximation.

Photodetachment microscopy provides us with a remarkable situation where the
electron

interference pattern has a clear-cut envelope. Experiments done with and without
a magnetic

field show a pattern shifted with no internal change, which demonstrates that
all

trajectories and fringes undergo the same macroscopic displacement together [4].
This has

important consequences for the reliability of electron affinity measurements
performed by

photodetachment microscopy. The property can actually be demonstrated by vector
analysis.

A non-zero second-order effect is expected however, which produces but a
negligible

phase-shift in the present experimental situations.

References

[1] W. Ehrenberg and R.E. Siday, Proc. Phys. Soc. B 62, 8 (1949)

[2] Y. Aharonov and D. Bohm, Phys. Rev. 115, 485 (1959)

[3] C. Blondel, C. Delsart and F. Dulieu Phys. Rev. Lett. 77, 3755 (1996)

[4] W. Chaibi, C. Blondel, C. Delsart and C. Drag, Europhys. Lett. 82, 20005
(2008)

PL 9

10

Laser Induced { Tunneling, Electron DiŽraction and

Molecular Orbital Imaging

Paul Corkum

University of Ottawa

National Research Council of Canada

Ottawa, Ontario, Canada

Multiphoton ionization in the tunneling limit is similar to tunneling in a
scanning tunnel-

ing microscope. In both cases an electron wave packet tunnels from a bound (or
valence)

state to the continuum. I will show that multiphoton ionization provides a route
to extend

tunneling spectroscopy to the interior of transparent solids. Rotating the laser
polariza-

tion is the analogue of scanning the STM tip - a means of measuring the crystal
symmetry

of a solid [1].

In gas phase molecules the momentum spectrum of individual electrons can be
measured.

I will show that, as we rotate the molecule with respect to the laser
polarization, the

photoelectron spectrum samples a ¯lter projection of the momentum wave function
(the

molecular analogue to the band structure) of the ionizing orbital [2].

Some electrons created during multiphoton ionization re-collide with their
parent ion. I

will show that they diŽract, revealing the scattering potential of the ion - the
molecular

structure [3]. The electron can also interfere with the initial orbital from
which it sepa-

rated, creating attosecond XUV pulses or pulse trains. The amplitude and phase
of the

radiation contains all information needed to re-construct the image of the
orbital [4] (just

as a sheared optical interferometer can fully characterize an optical pulse).

Strong ¯eld methods provide an extensive range of new tools to apply to atomic,
molecular

and solid-state problems.

[1] M. Gertsvolf, D. Grojo, D. Rayner and P. B. Corkum, unpublished results.

[2] A. Staudte, D. M. Villeneuve, M. Yu Ivanov and P. B. Corkum, unpublished
results.

[3] M. Meckel, D. Comtois, D. Zeidler, D. M. Villeneuve, R. DÄorner and P. B.
Corkum,

unpublished results.

[4] J. Itatani et al, Nature 432, 867 (2004).

PL 10

11

Few-electron dynamics

in the interaction with strong fields

Armin Scrinzi

Vienna U. of Technology, Photonics Institute

Simple single active electron models have been highly successful in describing
the interaction

of strong laser fields with atoms and have inspired a large number of
experiments.

Still, the validity and predictive power of these models for few-electron atoms
and in

particular for molecules remains to be investigated. There are only few
(semi-)analytical

models that include electron correlation. Alternatively, the numerical
integration of the

time-dependent Schr¨odinger equation (TDSE) is a challenging task because of the
exponential

growth of the problem size with the particle number, which has largely limited

computations to n = 2 active electrons.

In recent years, we have developed the MCTDHF (Multi-Configuration
Time-Dependent

Hartree-Fock) method for the solution of the TDSE for atoms and molecules in IR
laser

fields. The method scales like ∼ n

4 with the number of active electrons, as opposed to

the exponential scaling encountered in direct discretizations of the TDSE.
Different from

time-dependent density-functional theory, which has an even more favorable n

2-scaling,

MCTDHF allows for the straight forward computation of two-electron observables
and

for systematic convergence studies.

As examples, we show calculations of the strong field ionization of linear
molecules with

up to 6 active electrons, electron-assisted laser ionization of an atom, high
harmonic

generation on a diatomic 4-electron molecule, and the XUV-IR pump-probe
ionization of

Helium. While for our parameters, the effects of electron correlation on
ionization are

rather straight forward and can be incorporated into simple models, we find
dramatic

qualitative modifications of the high harmonic spectrum by multi-electron
effects. For

the pump-probe scenario, we find find significant crosstalk between the XUV pump
and

the IR probe pulses.

PL 11

12

Molecular reaction dynamics at low energies

Roland Wester

Department of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104
Freiburg,

Germany

Low-energy collisions of small molecules represent model systems for complex
quantum

reaction dynamics. The dynamics of negative ion reactions are particularly
interesting,

being characterized by a corrugated potential energy landscape that originates
in the

competition of long-range attractive and short-range repulsive forces.
Scattering on such

multi-dimensional potentials only leads to reaction products if the different
molecular

degrees of freedom are sufficiently coupled. This leads to unexpected dynamical
features

in the scattering cross sections.

To study ion-molecule reaction dynamics, we have developed two complementary
experimental

approaches. Using velocity map imaging in combination with crossed beams at

low energy, the differential scattering cross section of negative ion reactions
is measured

at a controlled relative energy [1]. This setup has allowed us to image the
nucleophilic

substitution reaction, a prototypical reaction in organic synthesis, and we have
observed

several distinct reaction mechanisms as a function of collision energy [2].
Currently we

are preparing experiments to investigate the stereodynamics of reactions that
take place

in a strong laser field.

Using a 22-pole ion trap, which allows for efficient buffer gas cooling of all
degrees of

freedom of trapped molecular ions, we study reaction rates of negative ions at
cryogenic

temperatures down to 8 Kelvin [3,4]. Due to the recent detection of negative
ions in interstellar

molecular clouds, these measurements have become important for understanding

the interstellar abundance of anions. Absolute cross sections for anion
photodetachment,

a significant destruction mechanism in photon dominated regions, are measured in
our

22-pole trap with high systematic accuracy [5]. In addition, we have observed
unexpected

temperature-dependences for a proton transfer reaction as well as for a ternary
cluster

stabilization reaction at low temperatures [6,7]. In the future this work will
be extended

to ultracold ion-atom interactions.

[1] J. Mikosch, U. Fr¨uhling, S. Trippel, D. Schwalm, M. Weidem¨uller, R.
Wester, Phys.

Chem. Chem. Phys. 8, 2990 (2006)

[2] J. Mikosch S. Trippel, C. Eichhorn, R. Otto , U. Lourderaj, J. X. Zhang, W.
L. Hase,

M. Weidem¨uller, R. Wester, Science 319, 183 (2008)

[3] J. Mikosch, U. Fr¨uhling, S. Trippel, D. Schwalm, M. Weidem¨uller, R.
Wester, Phys.

Rev. Lett. 98, 223001 (2007)

[4] J. Mikosch et al., submitted

[5] S. Trippel, J. Mikosch, R. Berhane, R. Otto, M. Weidem¨uller, R. Wester,
Phys. Rev.

Lett. 97, 193003 (2006)

[6] R. Otto et al., submitted

[7] J. Mikosch et al., submitted

PR 1

13

1, 2, 3 Photons for Trapped Ion Spectroscopy

C. Champenois, G. Hagel, M. Houssin, C. Zumsteg, F. Vedel, and M. Knoop

CNRS/Université de Provence, Centre de St.Jérôme, Case C21,

13397 Marseille Cedex 20, France

Rf trapped ions are versatile candidates for a large panel of applications
ranging from

quantum information to the creation of cold molecules. Sample size can range
from

a single to 106 ions, and the internal and external energy states of the atoms
can be

controlled with high precision. In our experiment, we focus on di erent
protocols in

frequency metrology using rf trapped Ca+ ions.

A single Ca+ ion, cooled in a miniature radiofrequency trap and con ned in the
Lamb-

Dicke regime, is an almost perfectly isolated atomic system suited for long
interroga-

tion times. The electric quadrupole transition between the ground 4S1=2 and the
upper

metastable 3D5=2 state is a rst choice for a frequency standard in the optical
domain, its

natural linewidth below 200 mHz results in a quality factor = higher than 2 1015
[1].

Probing of the clock transition of a single ion is carried out using quantum
jump statistics

which requires interrogation times of several seconds to avoid power broadening.
Care

must be taken to eliminate residual e ects which may perturb the one-photon
interro-

gation. The line width of the probe laser (local oscillator) should reach the
hertz level for

a duration at least as long as the interrogation time to take full advantage of
the quality

factor of the clock transition.

Clock performances are limited by the signal to noise ratio which can be
obtained on

a single ion. We propose a novel interrogation protocol allowing to separate the
two-

photon two-color cooling laser and the uorescence detection in two distinct
wavelength

domains, which allows detection without background and thus high cycle times. An

additional advantage is the tuning of the limit temperature only by the
variation of laser

detuning and power [2]. This protocol implying cooling on a dipole forbidden
transition

has been demonstrated experimentally [3].

The interrogation of an ion cloud by a three-photon protocol can be made in a
Doppler-

free con guration of the laser beams [4]. A coherent superposition of the two
metastable

states is obtained by a coherent population trapping protocol, providing a
high-resolution

dark line in the THz domain. The referenced 1.8 THz signal can be propagated
over long

distances, as the useful information is carried by three optical photons.

[1] C. Champenois et al., Phys. Lett. A 331/5, 298-311 (2004)

[2] C. Champenois et al., Phys. Rev. A 77, 033411 (2008)

[3] R. Hendricks et al., Phys. Rev. A 77, 021401(R) (2008)

[4] C. Champenois et al., Phys. Rev. Lett. 99, 013001 (2007)

PR 2

14

Non-linear Photoionization in the Soft X-ray Regime

Mathias Richter and Andrei A. Sorokin

Physikalisch-Technische Bundesanstalt, Berlin, Germany

The investigation of non-linear effects on photon-matter interaction like
multi-photon ionization

was restricted, for many years, to optical wavelengths. This has changed with
the

development of X-ray lasers like the Free-Electron LASer in Hamburg FLASH [1].
First

gas-phase studies performed at FLASH demonstrate that non-linear photoionization
in

the spectral range of the classical photoelectric effect, i.e. at photon
energies above atomic

ionization thresholds, differs in some respect from the behaviour in the optical
regime [2-

4]. Here, we present results of ion Time-Of-Flight (TOF) spectroscopy on rare
gases at

peak irradiance levels above 1013 W cm−2 up to 1016 W cm−2 and photon energies
around

40 eV and 90 eV. Non-linearities due to space-charge effects, target depletion,
and sequential

and direct multi-photon ionization were observed. Our result of 21-fold
ionization of

xenon seems to be even beyond a perturbative description [4]. The work is
related to

the development of photon diagnostic tools that are based on gas-phase
photoionization

but might be of significance for any experiment at current and future X-ray
laser facilities.

References

[1] W. Ackermann et al., Nat. Photonics 1, 336 (2007)

[2] A.A. Sorokin, S.V. Bobashev, K. Tiedtke, M. Richter, J. Phys. B 39, L299
(2006)

[3] A.A. Sorokin, S.V. Bobashev, K. Tiedtke, M. Wellh¨ofer, M. Richter, Phys.
Rev. A

75, 051402(R) (2007)

[4] A.A. Sorokin, S.V. Bobashev, T. Feigl, K. Tiedtke, H. Wabnitz, M. Richter,
Phys.

Rev. Lett. 99, 213002 (2007)

PR 3

15

Multi-photon ionization and excitation oft the rare

gases by Free Electron Laser radiation

Uwe Becker

Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany

Multi-photon processes in the vacuum ultraviolet and soft X-ray regions became
experi-

mentally accessible only very recently when the Free Electron Laser FLASH at
DESY in

Hamburg was put into operation. The high brilliance of its light pulses makes it
possible

to study non-linear processes in the photoionization of atoms, molecules and
clusters.

First priority in the study of these processes has the spectroscopy of atoms, in
particular

rare gas atoms. The study of non-linear processes in theses atoms was due to
their high

ionization thresholds with normal laser radiation not feasible; only the
SASE-FEL with

its ultra-bright VUV radiation made this now possible.

Studying the intensity dependence proved the well-known relationship between the
num-

ber of involved photons and the exponential behavior of photon intensity versus
ionization

probability. More interesting was the relationship between simultaneous and
sequential

double photo-ionization. Our preliminary data analysis points to a predominance
of the

latter by two photons, if the necessary threshold energy for this process is
exceeded. The

last in a way most interesting aspect in this regard is the angular distribution
of the

corresponding photoelectrons.

Multi-photon processes are characterized by photoelectron angular distributions,
which

re ect the number of photons involved in the ionization process. This general
rule is

clearly exhibited in our angular distribution results. However, the di erent
photolines

show very distinct di erences in this respect, which needs further theoretical
explanation.

PR 4

16

Ultracold deeply-bound Rb2 molecules

F. Lang1, K. Winkler1, C. Strauss1, R. Grimm1;2 & J. Hecker Denschlag1

1 Institut fÄur Experimentalphysik und Quantenzentrum, UniversitÄat Innsbruck,
A-6020

Innsbruck, Austria

2 Institut fÄur Quantenoptik and Quantuminformation der sterreichischen Akademie
der

Wissenschaften, A-6020 Innsbruck, Austria

The tremendous success of the ¯eld of ultracold atomic gases has triggered the
quest for

ultracold molecular gases. The production of such molecular gases was hindered
by the

absence of standard laser cooling techniques for molecules because of their
richer internal

structure. Other pathways to cold and dense samples of molecules such as
sympathetic

cooling or association of ultracold atoms are required. Association via Feshbach
reso-

nances has already led to quantum degenerate or nearly quantum degenerate
ultracold

molecular gases, but only in very weakly bound states with high vibrational
quantum

numbers. Such molecules are in general unstable under collisions with each
other.

We overcome this limitation by optically transferring weakly bound Rb2 Feshbach
molecules

to the intrinsically more stable ro-vibrational ground state of the triplet
potential. The

transfer is carried out in a single step using stimulated Raman adiabatic
passage (STI-

RAP) with an eąciency of about 60%, which is only technically limited. Because
we

begin with a nearly quantum degenerate gas of Feshbach molecules, we thus enter
for the

¯rst time the regime of an ultracold and dense ensemble of tightly bound
molecules. The

molecules which are held in a 3D optically lattice exhibit a lifetime longer
than 100 ms.

These results open the door for a new generation of experiments with tightly
bound ultra-

cold molecules allowing for investigations of ultracold collisions and
chemistry, production

of a molecular BEC, as well as molecular quantum optics.

PR 5

17

Manipulating cold molecular gases with intense

optical elds

P. F. Barker

Department of Physics and Astronomy, University College London

Over last few years we have been exploring the application of intense, far o
-resonant,

optical elds for manipulating the centre-of-mass motion of molecular gases using
large

optical potentials in the 100 K range. This unique means of control, which can
be applied

to essentially any gas, has been used to decelerate molecular beams from
supersonic speeds

to rest to creating cold stationary molecular ensembles. Using these tailored
light elds we

have also focused molecular beams to micron dimensions and have even brie y
trapped

room temperature gases. In this update I will review these experiments and
describe

more recent work, which is studying the role of laser-induced molecular
alignment on the

manipulation of molecules, and also the trapping and sympathetic cooling of
molecules

with ultracold atoms.

PR 6

18

Resonant laser spectroscopy in the soft X-ray region

Jos e R. Crespo L opez-Urrutia, S. W. Epp, and J. Ullrich

Max Planck Institute for Nuclear Physics,

Saupfercheckweg 1, 69117 Heidelberg, Germany

In vast regions of the universe highly charged ions (HCI) are the predominant
form of

visible matter. They also appear in nuclear fusion devices as well as in
high-temperature

laser produced plasmas. Yet, their electronic structure still remains a
challenge for both

theory and experiment. As a result of the limitations of traditional
spectroscopic methods

in the soft and hard x-ray regions, accuracy currently constrains our knowledge
of quantum

electrodynamics (QED) in strong elds. The application of laser spectroscopy to
such

studies, which in the visible and ultraviolet range has already led to the most
comprehensive

veri cation of a physical theory, QED, in weak elds, being even capable of
testing

the time drift of fundamental constants, was until now not possible due to the
lack of

appropriate light sources. Extending such precision tests to strong elds beyond
perturbation

theory has general implications for the formalism of other quantum eld theories,

nuclear physics and parity-non-conservation studies. In our experiment [1], HCIs
stored

in an electron beam ion trap(EBIT) were excited by tunable ultra-intense soft
x-rays generated

at the Free electron LASer in Hamburg (FLASH), the rst free electron laser in

the world operating in that spectral range. With this setup, resonant laser
excitation of

bound-bound electronic transitions, namely the 1s22s 2S1=2 to 1s22p 2P1=2;3=2
lines of the

Li-like Fe23+ ion at 48.6 and 65.5 eV and of the isoelectronic Cu26+, became
possible in

an energy range hitherto unattainable with powerful lasers. This and more recent
experiments,

yielding a relative statistical error of only 2 ppm corresponding to 0.1% of the
QED

contributions, demonstrate immediate potential to push the current limits of
precision by

up to three orders of magnitude. They allow for tests of the QED theory in a
regime in

which standard perturbation methods fail, in the environment of the highest
stationary

electromagnetic elds found in nature, in the vicinity of the nucleus. Future
experiments

at upcoming x-ray free electron lasers (X-FEL) like the Stanford Linear Coherent
Light

Source (LCLS) or the European X-FEL will pave the way into the hard x-ray
region, at

energies appropriate for even deeper probing of strong eld QED e ects.
Investigations of

the photoionization of HCI and precision determinations of the lifetimes of
excited states

are possible with this EBIT method. It will also allow establishing atomic
frequency

standards at these high photon energies by coupling laser emission by e.g.
high-harmonic

generation directly to bound-bound transitions of { ideally { hydrogen-like
ions, overcoming

the present uncertainties found in x-ray standards derived from solid-state
samples.

[1] S.W. Epp, J. R. Crespo L opez-Urrutia, G. Brenner, V. Mackel, P. H. Mokler,
R.

Treusch, M. Kuhlmann, M. V. Yurkov, J. Feldhaus, J. R. Schneider, M. Wellhofer,
M.

Martins, W. Wurth, and J. Ullrich, Phys. Rev. Lett 98, 183001 (2007)

PR 7

19

Resonances in Rare Gas Atoms:

Many-Electron Theory and Experiment

V. L. Sukhorukov

Rostov State University of Transport Communications,

344038 Rostov-on-Don, Russia

E-mail: vls@rgups.ru

Excitation processes in the rare gas atoms Ne, Ar, Kr and Xe with energies
between the

two lowest ionization thresholds mp5

3=2 and mp5

1=2(m = 2¡5) are dominated by resonances

stemming from mp5

1=2n`0[K]J autoionizing Rydberg states (ARS). These states provide

very suitable objects for the investigation of many-electron eŽects, both
outside the atomic

core, where the n`0- electron is localized, and inside the core, which is
responsible for the

lifetime of the ARS. Starting with the pioneering work of Beutler [1] these
resonances

have been intensively studied experimentally (see, e.g. [2{5]). The two main
properties

of the resonances which are derived from experimental spectra are the quantum
defect

¹`, which determines the resonance energy, and the autoionization width ¡n, i.e.
the

resonance lifetime ¿n = ~=¡n.

In this talk we focus on the in°uence of many-electron eŽects on the processes
responsible

for the excitation and decay of the ARS. The lineshapes used for the evaluation
of ¹` and

¡n are strongly dependent on the level from which the ARS are excited. In order
to gain

detailed insight into the dynamics for excitation and decay of the ARS, we
applied the

con¯guration interaction Pauli-Fock approach including the eŽects of core
polarization

(CIPFCP) [6,7]. Using the CIPFCP method, we calculated resonance parameters (¹`,

¡n) [4,8,9] and the absolute photoionization cross sections (including the
lineshapes) [5,9{

11] for a broad range (`0 = 0 ¡ 5) of the autoionizing resonances in the rare
gas atoms

Ne-Xe. By comparing measured ARS lineshapes with the computed pro¯les and
adopting

step-by-step inclusion of many electron eŽects in the calculations, the
important types of

electron correlations are identi¯ed.

Support of this work by the Deutsche Forschungsgemeinschaft is gratefully
acknowledged.

References

[1] H. Beutler, Z. Phys. 93, 177 (1935).

[2] J. Berkowitz, Adv. Chem. Phys. 72, 1 (1988).

[3] H. Hotop, D. Klar, and S. Schohl, Proc. 6th Int. Symp. on Resonance
Ionization

Spectroscopy (RIS-92) volume 128 of Inst. Phys. Conf., 45 (1992).

[4] I. D. Petrov, V. L. Sukhorukov, and H. Hotop, J. Phys. B 35, 323 (2002).

[5] I. D. Petrov et al J. Phys. B 39, 3159 (2006).

[6] I. D. Petrov, V. L. Sukhorukov, and H. Hotop, J. Phys. B 32, 973 (1999).

[7] I. D. Petrov et al Eur. Phys. J. D 10, 53 (2000).

[8] I. D. Petrov, V. L. Sukhorukov, and H. Hotop, J. Phys. B 36, 119 (2003).

[9] T. Peters et al J. Phys. B 38, S51 (2005).

[10] I. D. Petrov et al Eur. Phys. J. D 40, 181 (2006).

[11] I. D. Petrov, V. L. Sukhorukov, and H. Hotop, J. Phys. B 41, 065205 (11pp)
(2008).

PR 8

20

Attosecond spectroscopy in atoms and solids

Reinhard Kienberger

Max-Planck-Institut f¨ur Quantenoptik, Hans-Kopfermann-Straße 1, D-85748
Garching

The generation of ever shorter pulses is a key to exploring the dynamic behavior
of matter

on ever shorter time scales. Over the past decade novel ultrafast optical
technologies

have pushed the duration of laser pulses close to its natural limit, to the wave
cycle,

which lasts somewhat longer than one femtosecond (1 fs = 1015 s) in the
visible spectral

range. Time-resolved measurements with these pulses are able to trace atomic
motion

in molecules and related chemical processes. However, electronic dynamics inside
atoms

often evolve on an attosecond (1 as = 1018 s) timescale and require
sub-femtosecond

pulses for capturing them. Atoms exposed to a few oscillation cycles of intense
visible

or near-infrared light are able to emit a single electron and XUV photon
wavepacket of

sub-femtosecond duration [1, 2]. Precise control of these sub-femtosecond
wavepackets

have been achieved by full control of the electromagnetic field in few-cycle
light pulses

[3]. These XUV pulses together with the few-cycle (few-femtosecond) laser pulses
used for

their generation have opened the way to the development of a technique for
attosecond

sampling of electrons ejected from atoms or molecules [4]. This is accomplished
by probing

electron emission with the oscillating electric field of the few-cycle laser
pulse following

excitation of the atom by the synchronized sub-femtosecond XUV pulse. Sampling
the

emission of photo electrons in this manner allows time-resolved measurement of
the XUV

pulse duration as well as of the laser field oscillations [5]. After the full
characterization of

these tools, first experiments have been carried out to measure sub-femtosecond
behavior

of matter. Recently, the dynamics of the photoionization process on solids has
been studied

[6]. Not only that attosecond metrology now enables clocking on surface
dynamics,

but also the individual behaviour of electrons of dierent type (core electrons
vs. conduction

band electrons) can be resolved. Here, we measured a time delay of about 100

as on the emission of the aforemention two types of electrons. The information
gained in

these experiments may have influence on the development of many modern
technologies

including semiconductor and molecular electronics, optoelectronics, information
processing,

photovoltaics, electronically stimulated chemistry on surfaces and interfaces,
optical

nano-structuring, and interference eects in spectroscopy.

References

[1] M. Hentschel et al., Nature 501 (2001).

[2] R. Kienberger et al. Science 297, 1144 (2002).

[3] A. Baltuska et al., Nature 421, 611 (2003).

[4] R. Kienberger et al., Nature 427, 817 (2004).

[5] E. Goulielmakis et al. Science 305, 1267 (2004).

[6] A. Cavalieri et al., Nature 449, 1029 (2007).

PR 9

21

Above, Around, and Below Threshold Ionization

using Attosecond Pulses

Johan Mauritsson¤

Department of Physics, Lund University, P.O. Box 118, SE-221 00 Lund, Sweden

Attosecond pulses oŽer a new route to produce temporally localized electron wave
packets

that can easily be tailored by altering the properties of the attosecond pulses.
In this talk

we will present three diŽerent experiments where attosecond pulses are used to
inject

electron wave packets into a continuum which is dressed by an infrared laser
¯eld. By

tuning the central frequency of the attosecond pulses and/or changing the target
gas, the

initial energy of the wave packets is set to be either above, around, or below
the ionization

potential.

To capture the motion of electron wave packets created above or around the
ionization

potential we have developed a quantum stroboscope to record the electron
momentum

distribution from a single ionization event. The quantum stroboscope is based on
a

sequence of identical attosecond pulses that are used to release electrons into
a strong

laser ¯eld exactly once per laser cycle. With this periodicity, the pulses
create identical

electron wave packets that add up coherently, with the result that the
properties of an

individual wave packet can be studied stroboscopically. We use this technique to
study

the coherent electron scattering of electrons that are driven back to the ion by
the laser

¯eld [1].

For electron wave packets created below the ionization potential we ¯nd that the
ionization

is greatly enhanced by the presence of the infrared laser ¯eld and that this
enhancement

strongly depends on the timing between the attosecond pulses and the laser ¯eld.
We

show that this eŽect can be attributed to interference between consecutive wave
packets,

which indicates that the wave packets stay in the vicinity of the ion over an
extended

time period [2].

Using instead isolated attosecond pulses generated from an ultrashort,
carrier-envelope-

phase stabilized infrared laser with a time-dependent polarization [3] we show
that it is

possible to also probe ultrafast bound electron dynamics. These attosecond
pulses are

broad enough to excite coherently all the p-states in Helium and a fraction of
the contin-

uum. The wave packets created in Helium, partly trapped in the atomic potential,
are

probed by a 7 fs 750 nm infrared laser ¯eld, with an intensity of 3 £ 1012
W/cm2. Using

this method we can extract the amplitudes and the phase evolutions of the bound,
excited

states.

¤ Part of the work was done in collaboration with LSU, AMOLF, MPQ and CUSBO.

References

[1] J. Mauritsson et al., Phys. Rev. Lett. 100, 073003 (2008).

[2] P. Johnsson et al., Phys. Rev. Lett. 99, 233011 (2007).

[3] G. Sansone et al., Science 314, 443 (2006).

PR 10

22

Few-body physics with ultracold Cs atoms and

molecules

F. Ferlaino, S. Knoop, M. Mark, M. Berninger, H. SchÄobel, H. C. NÄagerl, and R.
Grimm

Institut fr Experimentalphysik, Innsbruck, Austria Institut fr Quantenoptik und

Quanteninformation, Innsbruck,Austria

Ultracold gases are versatile systems to study few-body physics because of full
control

over the external and internal degrees of freedom. Scattering properties can be
controlled

because of the magnetic tunability of the two-body scattering length in the
proximity of a

Feshbach resonance and weakly bound dimers can be produced. Here we
experimentally

study three- and four-body physics by investigating ultracold (30-250 nK)
atom-dimer

and dimer-dimer collisions with Cs Feshbach molecules in various molecular
states and Cs

atoms in diŽerent hyper¯ne states. Resonant enhancement of the atom-dimer
relaxation

rate is observed in a system of three identical bosons and interpreted as being
induced

by a trimer state, possibly an E¯mov state. A strong magnetic ¯eld dependence of
the

relaxation rate is also observed in a atom-dimer mixture made of non-identical
bosons.

Dimer-dimer inelastic collisions have been studied in a pure, trapped sample of
Feshbach

dimers in the quantum halo regime. We identify a pronounced loss minimum with
varying

scattering length along with a further suppression of loss with decreasing
temperature.

This observations provide insight into the physics of a few-body quantum system
that

consists of four identical bosons at large values of the two-body scattering
length.

CP 1

23

Weakly bound molecules : Analysis by the Lu-Fano method

coupled to the LeRoy-Bernstein model.

Haikel Jelassi, Bruno Viaris de Lesegno, Laurence Pruvost

Laboratoire Aimé Cotton, CNRS II, bat 505, campus dOrsay

91405 Orsay, France

E-mail: laurence.pruvost@lac.u-psud.fr

We have performed experiments on photo-association spectroscopy of cold 87Rb
atoms,

below the (5s1/2+5p1/2) dissociation limit. By applying the trap loss
spectroscopy method

[1] we have measured the binding energies of the weakly bound molecules,
associated to

the 0−

g , 0+

u and 1g symmetries.

Such weakly bound molecules are described by the dipole-dipole atom interaction
which

varies, according to the molecular symmetry, either as 1/R3 or as 1/R6, where R
is

the inter-nuclear distance. The eigen energies of the weakly bound molecules are
then

very close to those obtained by the well-known Le Roy-Bernstein (LRB) model [2].
The

discrepancies to the LRB law are due to the short distance behavior of the
molecular

potentials or to couplings between molecular potentials resulting from
interactions, for

example spin-orbit or spin-spin interactions.

To analyze the data, we have adapted the Lu-Fano (LF) method - well-known for
Rydberg

atoms - to the weakly bound molecules. Using the LRB law, a molecular quantum
defect

is defined and deduced from the data. The LF graph - quantum defect versus the
binding

energy - allows us to characterize the molecular potential and the couplings.

For the 0−

g molecular levels, we observe a linear LF graph, which is the signature of the

short range behavior of the molecular potential. A model for the barrier allows
us to

connect the slope to the barrier location [3]. The method has also been applied
to 85Rb

and 133Cs [4].

For 0+

u molecular levels, the LF graph exhibits sharp variations which indicate a
coupling

with a neighboring molecular series. The coupling is due to the spin-orbit
interaction

in the molecule. A two series model allows us to evaluate the coupling, to
identify two

perturbing levels of the (5s1/2+5p3/2) 0+

u series and to predict the energy position and the

width of its first pre-dissociated level. An experimental signal agrees with the
prediction

[4]. The method has also been successfully applied to 133Cs.

References

[1] P. D. Lett et al., Phys. Rev. Lett. 71, 2200 (1993)

[2] R. J. Le Roy, R. B. Bernstein, J. Chem. Phys. 52, 3869 (1970)

[3] H. Jelassi, B. Viaris De Lesegno, L. Pruvost, Phys. Rev. A. 73, 32501 (2006)

[4] H. Jelassi, B. Viaris De Lesegno, and L. Pruvost, AIP Conference
Proceedings, ISC

2007, 935, 203, (2007)

[5] H. Jelassi, B. Viaris De Lesegno, L. Pruvost, Phys. Rev. A. 74, 12510 (2006)

CP 2

24

Calculations of static polarizabilities of alkali dimers

and alkali hydrides. Prospects for alignment of

ultracold molecules.

Mireille Aymar,+, Johannes Deiglmayr¤, and Olivier Dulieu +

+Laboratoire Aimśe Cotton, CNRS and Univ Paris Sud, B^at. 505,91405 Orsay Cedex,

France

¤ Physikalisches Institut, UniversitÄat Freiburg, Hermann-Herder-Strasse 3,
79104

Freiburg, Germany.

The rapid development of experimental techniques to produce ultracold alkali
molecules

opens the ways to manipulate them and to control their dynamics using external
electric

¯elds. A prerequisite quantity for such studies is the knowledge of their static
dipole

polarizabilities.

We computed the variations with internuclear distance and with vibrational index
of the

static dipole polarizability components of all homonuclear alkali dimers
including Fr2, and

of all heteronuclear alkali dimers involving Li to Cs, in their electronic
ground state and

in their lowest triplet state and of alkali hydrides LiH to CsH in their ground
state. We

use the same quantum chemistry approach than in our work on dipole moments [1]
based

on pseudopotentials for atomic core representation, Gaussian basis sets, and
eŽective

potentials for core polarization. Polarizabilities are extracted from electronic
energies

using the ¯nite-¯eld method [2].

For the heaviest species Rb2, Cs2 and Fr2 and for all heteronuclear alkali
dimers and for

CsH, such results are presented for the ¯rst time. The accuracy of our results
on atomic

and molecular static dipole polarizabilities is discussed by comparing our
values with the

few available experimental data and elaborate calculations. We found that for
all alkali

pairs, the parallel and perpendicular components of the ground state
polarizabilities at the

equilibrium distance Re scale as (Re)3. Prospects for possible alignment and
orientation

eŽects with these molecules in forthcoming experiments are discussed.

[1] M. Aymar and O. Dulieu, J. Chem. Phys 122, 204302(2005).

[2] J. Deiglmayr, M. Aymar, M. WeidemÄuller, R. Wester, and O. Dulieu, submitted
to J.

Chem. Phys.

CP 3

25

Electrostatically extracted cold molecules from a

cryogenic buŽer gas

Laurens D. van Buuren, Christian Sommer, Michael Motsch, Markus Schenk,

Pepijn W.H. Pinkse, and Gerhard Rempe

Max-Planck-Institut fÄur Quantenoptik,

Hans-Kopfermann-Str. 1, 85748 Garching, Germany

Dense samples of cold polar molecules oŽer new perspectives in physics [1].
Studies of

cold collisions and chemical reactions as well as high precision measurements
will bene¯t

from these samples. For this kind of studies there is still need for new sources
which

deliver a high density and a high °ux of cold molecules.

We present a source which delivers a continuous, high-density beam of slow and
internally

cold polar molecules. In the source, warm molecules are injected into a
cryogenic cell,

in which their external and internal degrees of freedom are cooled by collisions
with a

helium buŽer gas [2]. Cold molecules are extracted out of the cryogenic
environment by

means of an electric quadrupole guide. Information on the state purity of the
extracted

beam is obtained by laser depletion of H2CO within the guide [3]. In future, the
beam

can be loaded into a large volume electrostatic trap (as previously shown [4])
to perform

for example collision experiments.

References

[1] J. Doyle, B. Friedrich, R. V. Krems and F. Masnou-Seeuws, Eur. Phys. J. D
31, 149

(2004).

[2] J. Weinstein, R. DeCarvalho, T. Guillet, B. Friedrich and J. Doyle, Nature
(London)

395, 148 (1998).

[3] M. Motsch, M. Schenk, L.D. van Buuren, M. Zeppenfeld, P.W.H. Pinkse, and G.

Rempe, Phys. Rev. A 76, 061402R (2007).

[4] T. Rieger, T. Junglen, S.A. Rangwala, P.W.H. Pinkse, and G. Rempe, Phys.
Rev.

Lett. 95, 173002 (2005).

CP 4

26

In-situ non-invasive quality control of packaged meat

using a micro-system external cavity diode laser at

671 nm for Raman spectroscopy

Heinz-Detlef Kronfeldt1, Heinar Schmidt1, Bernd Sumpf2, Martin Maiwald2,

Götz Erbert2, Günther Tränkle2

1Technische Universität Berlin, Institut für Optik und Atomare Physik

Sekr. EW 0-1, Hardenbergstr. 36, 10623 Berlin, Germany

2Ferdinand-Braun-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Straße 4,

12489 Berlin, Germany

Diode lasers are highly attractive for spectroscopic field applications where
small sizes and

low power consumption are prerequisites. They are available as light sources
from the blue

up to the mid infrared spectral range and are commonly used in sensor systems.
However,

in the ultraviolet and visible spectral ranges, which are of special interest to
fluorescence

and Raman spectroscopy, compact diode laser based devices with narrow spectral
width

are not commercially available.

In this presentation, we will show how micro-system technology can overcome
these problems

with a small size high power external cavity diode laser (ECDL) emitting at
671nm

with a small emission width suitable for Raman spectroscopy. All elements used
in these

devices are mounted on micro optical benches with a dimension of only (13 x 4 x

1)mm3. For our experiments the subassemblies were mounted on conduction cooled
packages

(CCP) with footprints of only (25 x 25)mm2.

The ECDL system includes a broad area device as gain material, micro-optics for
beam

shaping and a reflecting Bragg grating for wavelength stabilization. We present
results for

devices with an output power of 200mW and a stable emission at 671 nm. The
spectral

width of = 80pm ( ˜ 2 cm−1), which includes 95% of intensity fits within the

required spectral width of = 450pm ( ˜ 10 cm−1) for Raman bands of most liquid

and solid samples.

This micro-system laser device is implemented into a specifically designed Raman
sensor

for in-situ measurements of meat. Raman spectroscopy offers the advantages to
measure

non invasive and through the packaging. The sensor exploits the fingerprinting
characteristics

of Raman spectra for substance identification and to follow the physicochemical

and biochemical changes upon aging of meat products.

The Raman probe is characterized and first results of time-dependent Raman
measurements

of porcine musculus longissimus dorsi aged for up to 4 weeks at 5 C will be

presented. The usefulness of Raman spectroscopy will be discussed with a view of
integrating

the sensor in a handheld laser scanner for food control.

This work was supported by the BMBF funded project FreshScan 16SV2332.

CP 5

27

3H/3He mass ratio experiment MPIK/UW-PTMS in

the context of º-mass measurements

David Pinegar1, Christoph Diehl1, Robert Van Dyck, Jr.2, and Klaus Blaum1

1Max-Planck-Institut fÄur Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg,
Germany

2Department of Physics, University of Washington, Seattle, WA 98195-1560, USA

e-mail: pinegar@mpi-hd.mpg.de

Beta-spectrometer experiments to constrain neutrino masses (such as KATRIN [1]
and

the completed Mainz experiment [2]) have a long history, as do independent
helium¡3 and

tritium mass diŽerence measurements like the most precise result from SMILETRAP
[3].

The main goal of MPIK/UW-PTMS, the Max-Planck-Institute for Nuclear Physics /
Uni-

versity of Washington Penning Trap Mass Spectrometer collaboration, is to use
simulta-

neous axial-frequency-lock in two externally-loaded hyperbolic Penning traps to
perform

single-ion cyclotron frequency measurements for a determination of the 3H to 3He
mass

ratio with 10¡11 uncertainty. Ideally their mass diŽerence (which is easily
calculated

from the mass ratio) will be found with an uncertainty much smaller than the
tritium

¯-spectrum endpoint can be determined by the KATRIN experiment. For KATRIN, the

uncertainty on the endpoint depends on absolute calibration of the spectrometer
retard-

ing potential as well as several other factors. Because mechanisms causing
systematic

uncertainty in beta-spectrometers generally eŽect both the ¯tted endpoint E0 and
the

¯tted electron neutrino mass mº, agreement between the spectrum endpoint and
inde-

pendent mass diŽerence measurements should reinforce con¯dence in the
understanding

of KATRIN systematic uncertainties. Hopefully, in the future agreement at the ť
50 meV

level will be found, just as good agreement was found at the ť 2 eV level
between earlier

3H to 3He mass diŽerence measurements and beta-spectrometers of lower resolution
than

KATRIN.

References

[1] J. Angrik, et al., FZKA Scienti¯c Report 7090, MS-KP-0501, (2004).

[2] Ch. Kraus, et al., Eur. Phys. J. C, 40, 447{468, (2005).

[3] Sz. Nagy, et al., Europhys. Lett., 74, 404{410, (2006).

CP 6

28

Optical microtraps for cold atoms based on near-¯eld

diŽraction

S. Nic Chormaic1;2, T. N. Bandi2;3 and V. Minogin2;3;4

1Physics Department, University College Cork, Cork, Ireland

2Photonics Centre, Tyndall National Institute, Prospect Row, Cork, Ireland

3Dept. of Applied Physics and Instrumentation, Cork Institute of Technology,

Bishopstown, Cork, Ireland

4Institute of Spectroscopy, Russ. Ac. of Sciences, 142190 Troitsk, Moscow
Region,

Russia

E-mail: S.NicChormaic@ucc.ie

In recent years there has been signi¯cant interest in studies on the development
of neutral

atom traps and the applications thereof [1-4]. One novel approach to the
development

of miniature atom traps involves the optical near-¯elds formed by laser
diŽraction on an

array of circular apertures in a thin screen [5]. This approach can be adapted
in order

to fabricate an array of atom microtraps and, accordingly, produce a large
number of

trapped atomic microensembles from a single initial atomic cloud or beam.

In this paper, we propose and analyze such near-¯eld Fresnel-type atom
microtraps with

a characteristic aperture size approximately equal to the optical wavelength
incident on

the thin screen. Our analysis of the atom microtraps shows that, for a moderate
laser

intensity of about 10 W/cm2, the traps can store atoms with a kinetic energy
equivalent

to ť 100¹K, and with estimated lifetimes of ť 1 second.

Our analysis for 85Rb and 133Cs atoms shows that the potential well depth of the
micro-

traps is mainly determined by the intensity of the incident laser ¯eld and the
detuning.

By varying these two parameters one can achieve robust control over the trap
param-

eters. The incident laser intensity of 10 W/cm2 corresponds to about 0.5 ¹W of
laser

power incident on each individual aperture. With such trap parameters one can
perform

atom optics experiments by blending microfabrication technology with cold atoms
for site

selective addressing of microtraps.

References

[1] V. I. Balykin, V. G. Minogin, and V. S. Letokhov, Rep. Prog. Phys. 63, 1429
(2000)

[2] W. HÄansel, P. HommelhoŽ, T. W. HÄansch, and J. Reichel, Nature 413, 498
(2001)

[3] S. K. Sekatskii, B. Riedo, and G. Dietler, Opt. Comm. 195, 197 (2001)

[4] K. D. Nelson, X. Li, and D. S. Weiss, Nat. Phys. 3, 556 (2007)

[5] V. I. Balykin and V. G. Minogin, Phys. Rev. A 77, 013601 (2008).

CP 7

29

Optical Spectroscopy of Rubidium Rydberg Atoms

with a 297nm Frequency Doubled Dye Laser

Th. Becker, Th. Germann, P. Thoumany, G. Stania, L. Urbonas and T. H¨ansch

Max Planck Institute for Quantum Optics

Hans Kopfermann Str. 1

85748 Garching, Germany

Rydberg atoms have played an important role in atomic physics and optical
spectroscopy

since many years. Due to their long lifetime and the big dipole matrix element
between

neighbouring Rydberg levels they are an essential tool in microwave cavity-qed

experiments. Ultracold Rydberg gases are a promising candidate for realizing
controlled

quantum gates in atomic ensembles. In most experiments Rydberg atoms are
detected

destructively, where the optically excited atoms are first ionized followed by
an electronic

detection of the ionization products. A Doppler-free purely optical detection
was reported

in [1] in a room temperature cell and in [2] in an atomic beam apparatus using
the technique

of electromagnetically induced transparency. In all these experiments the
Rydberg

atoms are excited with two lasers in a two-step ladder configuration.

Here we show that Doppler-free purely optical spectroscopy is also possible with
a one

step excitation scheme involving a UV laser at 297 nm. We excite the 85Rb
isotope from

the 5S1/2 ground state to the 63P3/2 state with a frequency doubled dye laser in
a room

temperature gas cell without buffer gas. Rydberg transitions are detected by
monitoring

the absorbtion of 780 nm laser light which is superimposed on the UV light and
resonant

with one hyperfine component of the Rubidium D2 line. With these two lasers we
realize a

V-scheme and utilize the quantum amplification effect due to the different
natural lifetimes

of the upper levels of the two transitions: an excitation into the 63P level
hinders many

absorbtion-emission cycles of the D2 transition and leads to a reduced
absorption on that

line. We discuss the shape of the observed spectra in the context of electron
shelving and

EIT experiments.

By applying a frequency modulation to the UV laser, we can obtain dispersive
signals

which can be used to stabilize the laser to a specific Rydberg transition. By
shifting

the frequency of the 780 nm laser to crossover resonances in the saturated
absorbtion

spectrum of the D2 line, the stabilization point of the UV laser can be detuned
from

the resonance by discrete values. Using this idea, we demonstrate the stability
of the

frequency locking scheme with an atomic beam apparatus: if the detuned laser
hits the

atomic beam under a small angle, only atoms of a certain velocity class will be
transferred

to their upper level. We excite the atoms with pulses of 5 μsec duration and
measure

their arrival times 10 cm behind the excitation region with field selective
ionization. By

analyzing the time of flight spreading we can show that the long-term linewidth
of the

laser is below 2 MHz in the UV, which corresponds to the specified short time
stability

of the dye laser and the long term frequency drift can be effectively
compensated.

references:

[1] A. K. Mohpatra, T. R. Jackson, C. S. Adams, Phys. Rev. Lett. 98, 113003
(2007).

[2] S. Mauger, J. Millen and M. P. A. Jones, J. Phys. B: At. Mol. Opt. Phys. 40,
F319

(2007).

CP 8

30

Helium n1;3S excited states obtained with an angular

correlated con¯guration interaction method

K. V. Rodriguez1;4, V. Y. Gonzalez1;4, L. U. Ancarani2, D. M. Mitnik3;4

and G. Gasaneo1;4

1Departamento de Fś³sica - Universidad Nacional del Sur, 8000 Bahś³a Blanca,
Argentina

2Laboratoire de Physique Molśeculaire et des Collisions,

Universitśe Paul Verlaine - Metz, France

3Instituto de Astronomś³a y Fś³sica del Espacio, y Departamento de Fś³sica,
Facultad de

Ciencias Exactas y Naturales, Universidad de Buenos Aires. C.C. 67, Suc. 28,

(C1428EGA) Buenos Aires, Argentina

4Consejo Nacional de Investigaciones Cientś³¯cas y Tśecnicas, Argentina

We construct approximate helium wavefunctions for ground and excited n1;3S
states

through the angular correlated con¯guration interaction (ACCI) method proposed
in [1].

The trial wavefunctions are given by

ªC3¡N =

X

n1;n2;n3

'n1(r1)'n2(r2)ÂC3(n12; r12)

X

ijk6=1

cn1n2n12

ijk ri

1rj

2rk

12

where r1; r2; r12 are the interparticle coordinates. The products
'n1(r1)'n2(r2)ÂC3(n12; r12)

(with (n1; n2; n12 integers) were proposed by Gasaneo and Ancarani in [2] as
parameter-

free basis functions: 'ni are l = 0 hydrogenic functions, and ÂC3 = 1F1(¡n12;
2;¡r12=n12)

is the angular correlation factor [2,3] which results from the analytic
continuation of the

widely used double continuum three-body Coulomb (C3) wave function [4]. Each of
these

product satis¯es exactly all two-body Kato cusp conditions. Following the
methodology

proposed in [1], we multiply each of them by a series which does not aŽect this
property.

The trial wavefunction involves then N linear variational parameters cn1n2n12

ijk which are

obtained by solving a generalized eigenvalue problem. The n1;3S states obtained
in this

way form an orthogonal set of wavefunctions.

Quite accurate energies values for both the ground and excited states can be
obtained

with only a relatively low number of terms, as illustrated by the following
table (the

construction includes the 1s1s; 1s2s and 1s3s multiple con¯gurations and n12 up
to 2).

N n1 n2 n12 ¡E11S ¡E23S ¡E21S ¡E33S

24 1,2 1,2 1,2 2.90329 2.1752 2.14587 2.05589

38 1,2,3 1,2,3 1,2 2.90335 2.17521 2.14594 2.06866

52 1,2,3,4 1,2,3,4 1,2 2.90339 2.17522 2.14594 2.06869

Exact[5] 2.90372 2.17523 2.14597 2.06869

References

[1] K.V. Rodriguez, G. Gasaneo and D.M. Mitnik, J. Phys. B 40 (19), 3923 (2207).

[2] G. Gasaneo and L.U. Ancarani, Phys. Rev. A 77, 012705 (2008)

[3] L.U. Ancarani and G. Gasaneo, Phys. Rev. A 75, 032706 (2007)

[4] C.R. Garibotti and J.E. Miraglia, Phys. Rev. A 21, 572 (1980)

[5] G.W.F. Drake (ed) 2005 Springer Handbook of Atomic, Molecular, and Optical
Physics

CP 9

31

Atomic structure calculations of Cm+4 and Am+3 ions

G. Gaigalas1

,

2, E. Gaidamauskas1 and Z. Rudzikas1

1Vilnius University Research Institute of Theoretical Physics and Astronomy,

A. Goˇstauto 12, LT-01108 Vilnius, Lithuania

2Vilnius Pedagogical University, Student¸u 39, LT-08106, Vilnius, Lithuania

E:mail:gaigalas@itpa.lt

Modern technologies require knowledge of atomic structure of the most complex
chemical

elements, actinides included. The accuracy of the results obtained depends on
the degree

of accounting for correlation and relativistic effects. Many phenomena or
properties, e.g.

effective magnetic moments of the Cm

+4 ions measured in several compounds [1], still

remain unexplained. In this report we present ab initio calculations of the
lowest energy

terms and levels of Cm

+4 and Am

+3 ions in nonrelativistic approach.

For the calculation of energy spectra of Cm

+4 and Am

+3 ions we used multiconfigurational

Hartree-Fock and configuration interaction methods accounting for relativistic
efects in

Breit-Pauli approach. Configuration state functions of the multiconfiguration
expansion

additionally include single and double substitutions from the valence shell (VV
correla-

tions). All calculations were performed with the MCHF atomic-structure package
[2]. The

dependence of fine structure of the lowest term 7

F of Cm

+4 in Breit-Pauli approach on

correlation effects taken into consideration is presented in Table. The results
obtained

demonstrate that core-valence and core-core correlations are essential for the
Cm

+4 and

Am

+3 term energy, whereas their role in the case of fine structure is much less
compared

to that of valence-valence correlations. Therefore the latters must be accounted
for while

studying the fine structure of the ions. The calculated energy levels of the Cm

+4 are in

a good agreement with experimentally obtained values [3].

Table I. The lowest 7 energy levels of Cm

+4 in MCHF+BREIT (CI) approach with dif-

ferent degree of accounting for correlation effects.

States Energy Level (cm−1)

AS6 AS7 AS8 AS9 AS10 AS11 AS12

5f

6 7

F0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

7

F1 1788.0 2019.5 2105.6 2196.5 2225.6 2265. 4 2292.6

7

F2 4838.0 5464.5 5691.9 5935.8 6012.4 6118. 0 6182.9

7

F3 8188.9 9221.8 9566.6 9960.9 10079.6 10248. 2 10340.5

7

F4 11107.3 12422.6 12797.1 13284.9 13422.3 13628. 0 13728.3

7

F5 13656.3 15143.0 15492.3 16029.8 16171.7 16396. 2 16494.6

7

F6 16117.2 17681.3 17974.2 18527.4 18664.4 18894. 1 18983.6

References

[1] S.E. Nave, R. G. Haire, P.G. Huray, Phys. Rev. B. 28, 2317 (1983)

[2] C. Froese Fischer, G. Tachiev, G. Gaigalas, M.R. Godefroid, Comput. Phys.
Comm.

176, 559 (2007)

[3] G.K. Liu, J.V. Beitz, Phys. Rev. B. 41, 6201 (1990)

CP 10

32

MCDHF calculations of the electric dipole moment

of radium induced by the nuclear Schiff moment

E. Gaidamauskas1, G. Gaigalas1, J. Bieron2, S. Fritzsche3 and P. J¨onsson4

1Vilnius University Research Institute of Theoretical Physics and Astronomy,

A. Goˇstauto 12, LT-01108 Vilnius, Lithuania,

2Instytut Fizyki imienia Mariana Smoluchowskiego, Uniwersytet Jagiello´nski

Reymonta 4, 30-059 Krak´ow, Poland

3Gesellschaft f¨ur Schwerionenforschung Darmstadt, Planckstr.1, D-64291
Darmstadt,

Germany

4Nature, Environment, Society Malm¨o University, S-205 06 Malm¨o, Sweden

E-mail:gaigalas@itpa.lt

A non-zero permanent electric dipole moment (EDM) of atom, molecules or other
composite

or elementary particle is one of possible manifestations of parity (P) and time

reversal (T) symmetry violations. During the last decade, several atoms were
considered

as candidates for such experiments, and currently radium appears to be the most
promising

one. Experiments with radium are underway in Argonne National Laboratory and in

Kernfysisch Versneller Instituut. The multiconfiguration Dirac-Hartree-Fock
theory has

been employed to calculate the electric dipole moment of the metastable 7s6d

3

D2 state

of radium. One of the most important parity and time reversal symmetry violating
interaction

in atoms is due to a possible Schiff moment between the electrons and the
nucleus:

ˆH

SM = 4

N

X

j

=1

(S ˇ∇

j) (r

j) . (1)

This interaction mixes parity of atomic states and also induces a static
electric dipole

moment of the atom. For the calculations of the Schiff moment interaction and
electric

dipole moment operators matrix elements we extended the GRASP2K relativistic
atomic

structure package [1]. In the calculations valence and core-valence electron
correlation

effects have been included in a converged series of multiconfiguration
expansions. In this

contribution, we investigate the mixing of two atomic levels of opposite parity,
7s7p

3

P1

and 7s6d

3

D2, which are separated by a very small energy interval 5cm

−1. The calculated

values of EDM are presented in the Table. Obtained results are in a good
agreement with

other theories [2].

Table 1: EDM for different isotopes of Ra in the 3

D2 state induced by the Schiff moment.

223

88

Ra I = 3

2

F = 3

2

225

88

Ra I = 1

2

F = 3

2

MCDHF RHF+CI [2] MCDHF RHF+CI [2]

0.43 × 109

IS 0.30 × 109

IS 1.40 × 108

IS 0.94 × 108

IS

References

[1] P. J¨onsson, X. He, C. Froese Fischer, I.P. Grant, Comput. Phys. Comm. 177,
597

(2007)

[2] V.A. Dzuba, V.V. Flambaum, J.S. Ginges, Phys. Rev. A 61, 062509 (2000)

CP 11

33

On the solution of the time dependent Dirac

equation for hydrogen-like systems

S. Selstø, J. Bengtsson, E. Lindroth

Atomic Physics, Fysikum, Stockholm University, AlbaNova University Center,

SE-106 91 Stockholm, Sweden

The time dependent Dirac equation for a hydrogen-like system exposed to a short,
intense

electromagnetic pulse is solved numerically by expanding the wave function in
eigenstates

of the unperturbed Hamiltonian. These eigenstates are obtained by diagonalizing
the

Dirac Hamiltonian on an exponential grid. As the field parameters (field
strength and

frequency) increases, both magnetic and relativistic effects become important.
Furthermore,

for higher nuclear charges, relativistic effects are important even for
relatively weak

fields. The need for a non-dipole and relativistic treatments is investigated by
direct

comparison with the corresponding predictions of the Schr¨odinger equation in
the dipole

approximation.

Although the fields considered are far below the threshold for pair-creation,
negative

energy states may still play a role during the interaction. The possible
influence of such

states is considered by propagating the wave function in field dressed states,
which are

obtained by diagonalizing the full Hamiltonian. After each diagonalization the
negative

energy states are removed from the basis.

In order to minimize the number of basis states needed, complex scaling has been
applied.

CP 12

34

Calculation of parity-nonconserving amplitude in Ra+

Rupsi Pal1, Dansha Jiang1, Marianna Safronova1, and Ulyana Safronova2

1University of Delaware, Newark, Delaware, 19716 USA

2University of Nevada, Reno, Nevada, 89523, USA

E-mail: msafrono@udel.edu

Experimental measurements of the spin-dependent contribution to the PNC 6s ! 7s

transition in 133Cs led to a value of the cesium anapole moment that is accurate
to about

14% [1]. The analysis of this experiment, which required a calculation of the
nuclear spindependent

PNC amplitude, led to constraints on weak nucleon-nucleon coupling constants

that are inconsistent with constraints from deep inelastic scattering and other
nuclear

experiments. New experiments (and associated theoretical analyses) are needed to
resolve

the issue.

Comparing experimental weak charges of atoms QW, which depend on input from
atomic

theory, with predictions from the standard model provide important constraints
on possible

extensions of the standard model. Indeed, a recent analysis [2] of
parity-violating

electron-nucleus scattering measurements combined with atomic PNC measurements
placed

tight constraints on the weak neutral-current lepton-quark interactions at low
energy, improving

the lower bound on the scale of relevant new physics to 1 TeV.

We have calculated parity-nonconserving 7s − 6d amplitude E1PNC in Ra+, using
relativistic

high-precision all-order method where all single and double excitations of the

Dirac-Hartree-Fock wave function are included to all orders of perturbation
theory. Detailed

study of the uncertainty of the PNC amplitude is carried out; additional
calculations

are performed to evaluate the effect of the triple excitations and to estimate
some of the

missing correlation corrections. A systematic study of the parity-conserving
atomic properties,

including the calculation of the transition matrix elements, lifetimes,
hyperfine

constants, as well as dipole and quadrupole ground state polarizabilities, is
carried out.

The comparisons are made between the size of the correlation corrections in Ba+
and Ra+.

The results are compared with other theoretical calculations and available
experimental

values.

References

[1] C. S. Wood, S. C. Bennett, D. Cho, B. P. Masterson, J. L. Roberts, C. E.
Tanner, and

C. E. Wieman, Science 275, 1759 (1997).

[2] R. D. Young, R. D. Carlini, A. W. Thomas, and J. Roche, Phys. Rev. Lett. 99,
122003

(2007).

CP 13

35

Development of the CI + all-order method for

atomic calculations

Marianna Safronova1, M. G. Kozlov2, and W. R. Johnson3

1University of Delaware, Newark, Delaware, 19716 USA

2Petersburg Nuclear Physics Institute, Gatchina, 188300, Russia

3University of Notre Dame, Notre Dame, Indiana, 46556, USA

E-mail: msafrono@udel.edu

The development of the relativistic all-order method where all single and double
excitations

of the Dirac-Hartree-Fock wave function are included to all orders of
perturbation

theory led to accurate predictions for energies, transition amplitudes,
hyperfine constants,

and other properties of monovalent atoms as well as the calculation of
parity-violating

amplitudes in Cs and Fr [1]. The all-order method is designed to treat core-core
and corevalence

correlations with high accuracy. Precision calculations for atoms with several

valence electrons require an accurate treatment of the very strong
valence-valence correlation;

a perturbative approach leads to significant difficulties. In this work, we
develop

a novel method for precision calculation of properties of atomic systems with
more than

one valence electron. This method combines the all-order approach currently used
in precision

calculations of properties of monovalent atoms with the configuration
interaction

(CI) approach.

The precision of the CI method is generally drastically limited for large
systems by the

number of the configurations that can be included. As a result, core excitations
are

neglected or only a small number of them are included, leading to a significant
loss of

accuracy for heavy atoms. In the CI + all-order approach, core excitations are
incorporated

in the CI method by constructing an effective Hamiltonian using fully converged

all-order excitations coefficients. Therefore, the core-core and core-valence
sectors of the

correlation corrections for systems with few valence electrons will be treated
with the

same accuracy as in the all-order approach for the monovalent system. The CI
method

will then be used to treat valence-valence correlations. This method is expected
to yield

accurate wave functions for subsequent calculations of various atomic properties
(such as

lifetimes, polarizabilities, hyperfine constants, parity-violating amplitudes,
etc).

The preliminary results for Mg, Al, Sr, and Ba are presented.

References

[1] M.S. Safronova and W.R. Johnson, Advances in Atomic, Molecular, and Optical

Physics 55, 191 (2008).

CP 14

36

Ground state wavefunctions for two-electron systems

with ¯nite nuclear mass

K. V. Rodriguez1;4, V. Y. Gonzalez1;4, L. U. Ancarani2, D. M. Mitnik3;4

and G. Gasaneo1;4

1Departamento de Fś³sica - Universidad Nacional del Sur, 8000 Bahś³a Blanca,
Argentina

2Laboratoire de Physique Molśeculaire et des Collisions,

Universitśe Paul Verlaine - Metz, France

3Instituto de Astronomś³a y Fś³sica del Espacio, y Departamento de Fś³sica,
Facultad de

Ciencias Exactas y Naturales, Universidad de Buenos Aires. C.C. 67, Suc. 28,

(C1428EGA) Buenos Aires, Argentina

4Consejo Nacional de Investigaciones Cientś³¯cas y Tśecnicas, Argentina

The basis functions proposed by Gasaneo and Ancarani in [1] are used to
construct trial

wavefunctions for several two-electron systems. The focus here is on the study
of the

following negatively charged hydrogenlike ions : 1H¡, 1H¡; D¡, T¡ and Mu¡, the
negative

positronium ion Ps¡, and some exotic systems e¡e¡(nme)+ in which one of the
particles

is heavier than the other two. All these systems are similar to each other in
the main

property of their spectra, i.e. they have only one bound (ground), singlet state
with

angular momentum L = 0. The basis functions satisfy exactly all the two-body
Kato

cusp conditions. Following the methodology proposed in [2], each term of the
basis is

multiplied by a series which does not aŽect this property. In terms of the
interparticle

coordinates rij (i 6= j), the trial wave functions, with N the number of
(linear) variational

parameters, are constructed as

ªC3¡N =

X

n1;n2;n3

'n1(¹13; r1)'n2(¹23; r2)ÂC3(n3; ¹12; r12)

X

ijk6=1

cn1n2n12

ijk ri

1 rj

2rk

12

where ¹ij are the reduced masses, 'ni are l = 0 hydrogenic functions of
principal quantum

numbers ni, and ÂC3 = 1F1(¡n3; 2;¡2¹12r12=n3) with n3 a positive integer is the
angular

correlation factor [1,3] which results from the analytic continuation of the
widely used

double continuum three-body Coulomb (C3) wave function [4].

We also investigate systems of the form e¡e¡(nme)+ where (nme)+ refers to exotic
par-

ticles with masses m3 equal n times the mass of the positron but with the charge
of the

positron (+). Taking n from 1 to 1 we have obtained approximate analytical
expressions

for the energies and some mean radial quantities, as functions of the mass of
the heaviest

particle m3.

Results of the mean energy and other radial quantities will be shown at the
conference

for the ions 1H¡, 1H¡; D¡, T¡, Mu¡ and the exotic systems e¡e¡(nme)+.

References

[1] G. Gasaneo and L.U. Ancarani, Phys. Rev. A 77, 012705 (2008)

[2] K.V. Rodriguez, G. Gasaneo and D.M. Mitnik, J. Phys. B 40 (19), 3923 (2007)

[3] L.U. Ancarani and G. Gasaneo, Phys. Rev. A 75, 032706 (2007)

[4] C.R. Garibotti and J.E. Miraglia, Phys. Rev. A 21, 572 (1980)

CP 15

37

Laser separation and detecting the isotopes and

nuclear reaction products and relativistic calculating

the hyper¯ne structure parameters in the

heavy-elements

O.Yu. Khetselius

Odessa University, P.O.Box 24a, Odessa-9, 65009, Ukraine

Relativistic calculation of the spectra hyper¯ne structure parameters for heavy
elements

is carried out. Calculation scheme is based on gauge-invariant QED perturbation
theory

with using the optimized one-quasiparticle representation at ¯rst in the theory
of the hy-

per¯ne structure for relativistic atomic systems [1,2]. Within the new method it
is carried

out calculating the energies and constants of the hyper¯ne structure for valent
states of

cesium 133Cs, Cs-like ion Ba, isotopes of 201Hg, 223Ra, 252Cf are de¯ned. The
con-

tribution due to inter electron correlations to the hyper¯ne structure constants
is about

120-1200 MHz for diŽerent states, contribution due to the ¯nite size of a
nucleus and

radiative contribution is till 2 dozens MHz. Obtained data for hyper¯ne
structure param-

eters are used in further in laser photoionization detecting the isotopes in a
beam and the

buŽer gas for systematic studying the short-lived isotopes and nuclear isomers.
We pro-

pose a new approach to construction of the optimal schemes of the laser
photoionization

method for further applying to problem of the nuclear reactions products
detecting. It's

studied the reaction of spontaneous 252Cf isotope ¯ssion on non-symmetric
fragments,

one of that is the cesium nucleus. The corresponding experiment on detecting the
reac-

tions products is as follows. The heavy fragment of the Cf nucleus ¯ssion
created in the

ionized track 106 electrons which are collected on the collector during 2 mks.
The collec-

tor is charged negatively 40mks later after nuclear decay and 10mks before the
laser pulse

action. The photo electrons, arised due to the selective two-stepped
photoionization are

drafted into the proportional counter for their detecting. Usually a resonant
excitation of

Cs is realized by the dye laser pulse , the spectrum of which includes the
wavelengths of

two transitions 6S1/2-7P3/2 (4555A) and 6S1/2-7P1/2 (4593A). This pulse also
realizes

non-resonant photoionization of the Cs excited atoms. The disadvantages of the
standard

scheme are connected with non-optimality of laser photoionization one, eŽects of
impact

lines broadening due to the using the buŽer gas, the isotopic shift and hyper¯ne
struc-

ture masking etc. We proposed new laser photoionization scheme, which is based
on a

selective resonance excitation of the Cs atoms by laser radiation into states
near ioniza-

tion boundary and further autoionization decay of excited states under action of
external

electric ¯eld [2]. The corresponding optimal parameters of laser and electric
¯elds, atomic

transitions, states, decay parameters etc are presented.

References

[1] A. Glushkov, O. Khetselius et al, Nucl. Phys. A. 734, e21 (2004)

[2] A. Glushkov, O. Khetselius et al, Recent Adv. in Theory of Phys. and Chem.
Syst.

(Springer). 15, 285 (2006)

CP 16

38

QED approach to the photon-plasmon transitions

and diagnostics of the space plasma turbulence

A.V. Glushkov12, O.Yu. Khetselius2, A.A. Svinarenko2

1Institute for Spectroscopy of Russian Academy of Sciences, Troitsk, 142090,
Russia

2Odessa University, P.O.Box 24a, Odessa-9, 65009

Energy approach in QED theory [1-4] is developed and applied to modelling
photon-

plasmon transitions with emission of photon and Langmuir quanta in space and
astro-

physical plasma. It is well known that the positronium Ps is an exotic hydrogen
isotope

with ground state binding energy of E = 6:8 eV. The hyper¯ne structure states of
Ps

diŽer in spin S, life time t and mode of annihilation. The ortho-Ps atom has a
metastable

state 2s1 and probability of two-photon radiation transition from this state
into 1s1 state

0:0018s¡1. In the space plasma there is the competition process of destruction
of the

metastable level - the photon-plasmon transition 2s ¡ 1s with emission of photon
and

Langmuir quanta. We carried out calculation of the probability of the
photon-plasmon

transition in the Ps. The approach represents the decay probability as an
imaginary part

of energy shift dE, which is de¯ned by S-scattering matrix. Standard S-matrix
calcula-

tion with using an expression for tensor of dielectric permeability of the
isotropic plasma

and dispersion relation- ships for transverse and Langmuir waves allows getting
the cor-

responding probability P(ph ¡ pl). Numerical value of P(ph ¡ pl) is 5:2 ¢
106U(1=s),

where U is density of the Langmuir waves energy. Our value is correlated with
others:

P(ph¡pl) = 6¢106U(1=s). Comparison of obtained probability with lifetime t (3
gamma)

allows getting the condition of predominance of photon- plasmon transition over
three-

photon annihilation. The considered transition may control the population of 2s
level and

search of the long-lived Ps state can be used for diagnostics of the plasma
turbulence.

References

[1] A. Glushkov, L.N. Ivanov, Phys. Lett.A. 170, 33 (1992); Preprint ISAN N
AS-4,

Moscow-Troitsk (1994)

[2] A. Glushkov, et al, J. Phys. CS. 11, 188 (2004)

[3] A. Glushkov, et al, Int. Journ. Quant. Chem. 99, 936 (2004)

[4] A. Glushkov, Low Energy Antiproton Phys. 796, 206 (2006)

CP 17

39

QED theory of laser-atom and laser-nucleus

interaction

A.V. Glushkov12

1Institute for Spectroscopy of Russian Academy of Sciences, Troitsk, 142090,
Russia

2Odessa University, P.O.Box 24a, Odessa-9, 65009

QED theory is developed for studying interaction of atoms and nuclei with an
intense

and superintense laser ¯eld. Method bases on a description of system in the ¯eld
by the

k- photon emission and absorption lines. The lines are described by their QED
moments

of diŽerent orders, which are calculated within Gell-Mann Low adiabatic
formalism [1-

4]. The analogous S-matrix approach is developed for consistent description of
the laser-

nucleus interaction. We have studied the cases of single-, multi-mode, coherent,
stochastic

laser pulse shape. An account for stochastic °uctuations in a ¯eld eŽect is of a
great im-

portance. Results of the calculation for the multi-photon resonance and
ionization pro¯le

in Na,Cs, Yb, Gd atoms are presented. It is also studied the phenomenon of the
above

threshold ionization. Eąciency of method is demonstrated by QED perturbation
theory

calculations for the two-photon ionization cross-sections for extended photon
energy range

(including above-threshold ionization) in Mg. Comparison with the R-matrix
calculation

of Luc-Koenig et al [3] is given. There is considered a phenomenon of the
Rydberg stabi-

lization of the H atom in a strong laser ¯eld and estimated the rate of
transition between

the stabilized Rydberg state (n=40,m=2; E 10(8)V/cm ) and ground state, when
it's

possible the radiation of photons with very high energy (short-wave laser
ampli¯cation).

DC strong ¯led Stark eŽect for atoms, including atoms in plasma, Rydberg atoms
and

con¯ned systems is studied within new quantum approach, based on the operator PT
[1].

The zeroth order Hamiltonian, possessing only stationary states, is determined
only by its

spectrum without specifying its explicit form. We present here the calculation
results of

the Stark resonances energies and widths for a number of atoms (H, Li, Tm,U
etc.) and

for a whole number of low-lying and also Rydberg states. We discovered and
analyzed

the weak ¯eld eŽect of drastic broadening of widths of the Letokhov-Ivanov
re-orientation

decay autoionization resonances in Tm etc. Developed approach can be naturally
applied

to studying the Stark eŽect in con¯ned systems, including quantum wells, quantum
dots

etc, where especially interesting eŽects may occur.

References

[1] A. Glushkov, L.N. Ivanov, Phys. Lett.A. 170, 33 (1992); Preprint ISAN N
AS-2,

Moscow-Troitsk (1992)

[2] A. Glushkov, et al, J. Phys. CS. 11, 188 (2004)

[3] A. Glushkov, et al, Int. Journ. Quant. Chem. 99, 936 (2004); 99, 889 (2004);
104,

512 (2005); 99, 562 (2005);

[4] A. Glushkov, Low Energy Antiproton Phys. 796, 206 (2006)

CP 18

40

Quantum dynamics of planar hydrogen atom in a

billiard with moving boundaries

Kh.Yu. Rakhimov

Heat Physics Department of the Uzbek Academy of Sciences,

28 Katartal St., Tashkent 100135, Uzbekistan

kh rakhimov@yahoo.com

Particle motion in con¯ned geometries is an important problem providing to
explore

many features of classical nonlinear dynamics and quantum dynamics of
classically non-

integrable systems. Due to recent progress in the physics of mesoscopic systems
and

nanophysics this problem has become attractive from the practical viewpoint,
too. Such

systems as quantum dots, trapped atoms, nanotubes are the realistic systems
where con-

¯ned electron dynamics play important role. Usually in studying these systems
the bound-

aries of con¯nement are considered as strictly ¯xed. However, in many
practically impor-

tant situations the con¯nement boundaries are not strictly ¯xed and °uctuate in
space,

oscillate or move in one direction.

In present work we study quantum dynamics of an electron in the Coulomb ¯eld
whose

motion is con¯ned by time-dependent billiard boundaries. Exploring of billiards
with

moving walls require solution of the two-dimensional SchrÄodinger equation with
time-

dependent boundary conditions. Here we solve the SchrÄodinger equation for
Coulomb

potential with the boundary conditions given on circle with time-dependent
radius. It

well known that in most of the realistic situations with atoms con¯ned in
various traps

the trap boundaries are not ¯xed but time-dependent. Solving the problem
numerically

we obtain time-dependence of the electron energy and compute density of states.
The

results obtained show that in the case of oscillating boundaries the energy of
electron

grows in time. However, this growth is strongly suppressed upon reaching certain
value.

This value depends on the frequency and amplitude of the billiard wall
oscillations.

CP 19

41

Interchannel interaction in orientation and alignment

of Kr 4p4mp states in the excitation region

of 3d9np resonances

B.M. Lagutin1, I. D. Petrov1, V. L. Sukhorukov1, A. Ehresmann2, L.Werner2,

S. Klumpp2, K.-H. Schartner3 and H. Schmoranzer4

1Rostov State University of Transport Communications, 344038 Rostov-on-Don,
Russia,

2Institut fÄur Physik, UniversitÄat Kassel, 34109 Kassel, Germany,

3I. Physikalisches Institut, Justus-Liebig-UniversitÄat, D-35392 Giessen,
Germany,

4Fachbereich Physik, Technische UniversitÄat Kaiserslautern,

D-67653 Kaiserslautern, Germany

E-mail: schmoran@rhrk.uni-kl.de

In combined theoretical and experimental eŽorts we studied the interchannel
interaction

in°uencing the population of Kr 4p4mp ionic states in the excitation energy
region around

the 3d9np resonances by photon-induced Auger decay. This resonant Auger process
was

shown to be treated as an interference of strong resonant and weak direct
nonresonant

ionization channels [1]. This interference leads to the energy dependence of the
orientation,

O10, and the alignment, A20, of the ¯nal ionic states and also of the angular
distribution

of outgoing electrons and °uorescence photons. The above quantities are rather
sensitive

to the interference mechanism, especially when studied in the wings of the
resonances [2].

In the present work the theoretical treatment of the non-resonant pathway was
extended

with respect to the monopole shake-process considered earlier. The non-monopole
pro-

cesses including both intra- and intershell correlations were taken into
account. The

main non-monopole contributions to the direct transition amplitude stem from the
4p5"0`

(` = s; d) and 3d9"0` (` = p; f) intermediate states.

Correlation eŽects modify the partial monopole shake-amplitudes for the outgoing
waves

"` diŽerently and this eŽect changes the energy dependence of the O10 and A20
parame-

ters. The calculated data agree closely with the measured orientation parameter
for the

4p4(1D)5p 2P3=2 ¯nal ionic state in the extended energy region between the 3d9

5=25p3=2

and 3d9

5=26p3=2 resonances. This result asks for new extended experimental data on the

angular distribution parameters for other ¯nal ionic states, too.

The quality of the wavefunctions used in the calculation was checked by
comparing the

computed and recently measured [3] photoionization cross sections for diŽerent
4p4(L0S0)mp

satellites in the region of the 3d9np resonances. Good agreement between theory
and ex-

periment was observed in all cases. The photoelectron angular distribution
measured and

computed in [3] for the above satellites is also compared with the present
calculations.

References

[1] Lagutin B.M. et al., Phys.Rev.Lett. 90, 073001 (2003)

[2] Schartner K.-H. et al., J.Phys.B 40, 1443 (2007)

[3] Sankari A. et al., Phys.Rev.A 76, 022702 (2007)

CP 20

42

Application of new quasirelativistic approach for

treatment of oxygen-like Iron and Nickel

O. Rancova, P. Bogdanovich and R. Karpu skien_e

Institute of Theoretical Physics and Astronomy of Vilnius University

A. Go stauto st. 12, 01108 Vilnius, Lithuania

E-mail: olga@itpa.lt

An urgent demand for high precision calculations of atomic characteristics of
heavy atoms

and highly charged ions with complex electron con gurations encourages the
development

of new methods and computer codes. Possibilities of the new quasirelativistic
approach

designed for ab initio calculations of spectral characteristics of highly
charged ions and

heavy atoms are investigated and illustrated with an example of a study of
spectral

characteristics of oxygen-like ions of Iron and Nickel. Within the
quasirelativistic approach

the main relativistic e ects are taken already into account when obtaining the
radial

orbitals. The main distinctions between the approach under investigation and the
well-

known computer code by R. D. Cowan based on the methods described in [1] are the

following: the quasirelativistic equations for the radial orbitals are newly
formed in a

di erent shape [2,3], the nite size of the atomic nucleus is taken into account
while

solving the equations [4], the de nition of the radial integrals of the energy
operator is

re ned, the transformed radial orbitals are created for the description of
virtual excitations

while performing the con guration interaction.

The calculations executed within the described approach were reduplicated by the
ana-

logical calculations based on the usual non-relativistic radial orbitals. It
allows one to

evaluate the advantages and the new possibilities appearing while using the
quasirela-

tivistic radial orbitals against the conventional non-relativistic radial
orbitals when the

correlation e ects are taken into account in the same way performing the con
guration

interaction on the basis of transformed radial orbitals.

The energy spectra, transition characteristics and lifetimes of Fe XIX and Ni
XXI ions

calculated by two mentioned methods are calculated. The obtained results are
compared

with the experimental data and with the theoretical calculations of other
authors. From

the comparison it is obvious that the quasirelativistic approach enables us to
obtain the

data of high precision and that the structure of the energy spectra calculated
perfectly

coincides with the experimental spectra.

Acknowledgments

This work, partially supported by the European Communities under the contract of
As-

sociation between EURATOM/LEI FU06-2006-00443, was carried out within the frame-

work of the European Fusion Development Agreement. The views and opinions
expressed

herein do not necessarily re ect those of the European Commission.

References

[1] R. D. Cowan, The theory of atomic structure and spectra, (University of
California

Press, Berkeley, 1981)

[2] P. Bogdanovich, O. Rancova, Phys. Rev. A 74, 052501 (2006)

[3] P. Bogdanovich, O. Rancova, Phys. Rev. A 76, 012507 (2007)

[4] P. Bogdanovich, O. Rancova, Lithuanian. J. Phys. 42, 257 (2002)

CP 21

43

Relativistic recoil and higher-order electron

correlation corrections to the transition energies in

Li-like ions

Y. S. Kozhedub1, D. A. Glazov1, I. I. Tupitsyn1, V. M. Shabaev1, and G. Plunien2

1 Department of Physics, St. Petersburg State University, Oulianovskaya 1,

Petrodvorets, St. Petersburg 198504, Russia

2 Institut fur Theoretische Physik, TU Dresden, Mommsenstra e 13, D-01062
Dresden,

Germany

E-mail: kozhedub@pcqnt1.phys.spbu.ru

Traditionally, investigations of isotope shift in atomic spectra have been
carried out mainly

to determine the di erence in the root-mean-square nuclear radii hr2i. Recently
new

applications emphasized the relevance of this e ect. For instance, isotope shift
calculations

in atoms and ions can be important for astrophysical search for possible
-variation,

where the isotope shift induces valuable systematic error. Moreover,
investigations of this

e ect could provide information about isotopic abundances in the early Universe,
which

is tightly linked with the general evolution of the Universe. The study of
isotope shifts in

highly charged ions has the potential advantage of an increased sensitivity to
nuclear size

and relativistic e ects due to the stronger overlap of the electronic wave
function with

the nuclear matter and of the simpler electronic structure of few-electron ions
as opposed

to their neutral atomic counterparts.

Nuclear recoil e ect is the most di cult part of isotope shift to evaluate. In
the present

paper, we perform accurate calculations of the nuclear recoil e ect for ions
along the

lithium isoelectronic sequence. The full relativistic theory of the nuclear
recoil e ect

can be formulated only in the framework of QED [1]. In order to evaluate the
recoil

e ect within the lowest-order relativistic approximation one can use the
relativistic recoil

operator. Within this approximation the recoil correction is calculated with
many-electron

wave functions in order to take into account the electron-correlation e ect. The
one- and

two-electron contributions to the recoil e ect are evaluated to all orders in Z.
Comparing

the isotope shifts calculated with recent experimental data indicates very good
prospect

for test of the relativistic theory of the recoil e ect in middle-Z ions.

We present also the most accurate up-to-date theoretical values of the 2p1=2-2s
and 2p3=2-

2s transition energies in middle-Z Li-like ions. All presently available
contributions to

the transition energies are collected. Except for the one-electron two-loop
corrections, all

other terms up to the two-photon level are treated within the framework of
bound-state

QED to all orders in Z. The interelectronic interaction beyond the two-photon
level

is evaluated within the Breit approximation by means of the large-scale con
guration-

interaction Dirac-Fock-Sturm method. We report accurate numerical values of the
higher-

order interelectronic-interaction correction for Li-like ions up to uranium. The
results

obtained for the transition energies are in good agreement with recently
published exper-

imental data. In the case of lithiumlike scandium, they were reported in Ref.
[2].

References

[1] V. M. Shabaev, Phys. Rev. A 57, 59 (1998); Phys. Rep. 356, 119 (2002).

[2] Y. S. Kozhedub et al., Phys. Rev. A 76, 012511 (2007).

CP 22

44

Coupled tensorial forms of atomic two-particle

operator

R. Jurˇs˙enas

Institute of Theoretical Physics and Astronomy of Vilnius University, A.
Goˇstauto 12,

LT-01108 Vilnius, Lithuania

For many-electron atoms and ions the ability to present a two-electron operator
and its

matrix elements in an optimal form may be decisive for successful calculation
solutions

of many theoretical spectroscopy problems. Here a two-particle operator is
expressed in

second quantization representation (SQR). Special attention is paid to the
approach when

the expressions for the operator considered are given in terms of submatrix
elements of the

coupled two-electron wave function [1]. This gives more freedom in choosing a
convenient

way for the calculations of matrix elements for open-shell atoms.

In a SQR two approaches were considered to express an arbitrary two-electron
operator

in a coupled tensorial form for multi-shell atoms. The expressions of both
topologically

different approaches are applicable to the study of the operators representing
atomic interactions

as well as the operators describing some effective interactions appearing, for

instance, in an atomic many body perturbation theory (MBPT) or a coupled cluster

method.

The first approach is more suitable when one seeks effectively to calculate the
matrix

elements of (one) particular operator because the internal ranks of operator are
involved

in the calculation of many-electron angular part. The second approach is
superior for

the problems where several operators with different tensorial structure are
considered, for

example, the formation of energy matrix of atomic Hamiltonian in Breit-Pauli
approximation.

In this case, only the resulting ranks of operators enter in the expressions for
the

submatrix elements of many-electron angular part and the computer codes used for
such

calculations could be more efficient if they are based on the second approach.

The final result of the study is a large set of a two-particle operators acting
in the space

of the states of one-, two-, three- and four-shells. The expressions can be used
for both

nonrelativistic (LS coupling) and relativistic (jj coupling) approximations.

References

[1]. R. Jurˇs˙enas, G. Merkelis, Lithuanian Journal of Physics, Vol.47, No.3,
255-266 (2007).

CP 23

45

The binominal potential of electron-proton interaction

alternative to the Coulomb law

V.K. Gudym1 and E.V. Andreeva2

1Space National Agency of Ukraine, Kyiv, Ukraine

2Institute of Physics of Semiconductors of the NASU, Kyiv, Ukraine

E-mail:vgudym@mail.ru

On the basis of only classical assumptions, we have shown earlier [1, 2, 3] that
an electron

and a proton interact by the binomial law

V =

e2

r

+

r2 (1)

and have determined the value of the constant as 6:10276 1028 CGSE units.

Potential (1) has been veri ed by us in the analysis of both the Kepler task of
a hydrogen

atom where the energy takes the form

E = mr_2

2

+ M2

2mr2

e2

r

+

r2 (2)

and the Schrodinger equation

+

2m

h2

E + e2

r

r2

!

= 0 : (3)

We have also analyzed the scattering of an electron by a proton, as a special
case of the

Kepler task. Below, we give the formula for the de ection angle '0b as a
function of the impact

parameter :

'0b =

s

E 2

E 2 +

arccos

2

4

1 +

4E(E 2 + )

e4

!1=2

3

5 : (4)

The calculations have shown that the formula describing the scattering of
electrons in the binomial

potential well represents the process within the range of impact parameters down
to

1013cm for the energies of an electron from several eV up to hundreds of MeV .
Further, on

the basis of potential (1), we have shown the basic opportunity for the solution
of the classical

task concerning the movement of an electron in the eld of a proton for a
hydrogen atom. On

this way, we were succesful to clarify the nature of the Bohr postulates, the
Planck constant,

and some other constants which were not treated earlier within the framework of
classical mechanics.

For the theory of Schrodinger, we have demonstrated, with the use of potential
(1), the

opportunity to understand and to resolve a number of its internal
contradictions. In particular,

it turns out to be possible to derive, for the rst time, a wave package being
stable in time in

the problem concerning a hydrogen atom and to explain the mechanism of birth of
a quantum

in the classical interpretation.

Generally, potential (1) can be considered as a link between the classical and
quantum

theories.

References

[1] Gudym V.K. 2001, Visnyk Kyiv. Univ., N. 3, P. 254.

[2] Gudym V.K., Andreeva E.V. 2003, Poverkhn., N. 5, P. 59-63.

[3] Gudym V.K., Andreeva E.V. 2006, Poverkhn., N. 3, P. 113-117.

CP 24

46

The dynamics of meta-stable states described with a

complex scaled Hamiltonian

J. Bengtsson, E. Lindroth, and S. Selst

Atomic Physics, Fysikum, Stockholm University, S-106 91 Stockholm, Sweden

The laser development has given access to light pulses in the femto- and
subfemtosecond

regime and thereby opened the possibility to follow electron dynamics directly
in the time

domain. Of special interest is the dynamics of resonant states, and pioneering
experi-

mental studies were made a few years ago on the Auger decay of inner-shell
vacancies [1].

One widely spread theoretical technique, that successfully describes resonant
states, is

that of complex scaling. With this method, the meta-stable states are obtained
as unique

eigenstates to the eld-free complex scaled Hamiltonian. The half-width and the
energy

position of the meta-stable state is furthermore given directly from the
imaginary and the

real part of the corresponding eigenvalue respectively. Compared to many other
methods,

such as the stabilization method where the manifestation of a resonant state is
seen as a

local accumulations of pseudo-continuum states, this property is highly
attractive from a

numerical point of view. A second appealing property, due to complex scaling, is
that the

continuum is adequately represented by a very modest number of eigenstates. A
similar

accuracy cannot be achieved using a conventional pseudo continuum. Due to the
reasons

mentioned above, the method of complex scaling is also interesting for truly
dynamical

systems, for instance atoms exposed to short light pulses followed by the
possible popu-

lation of a meta-stable state. However, the complex scaled Hamiltonian is
non-Hermitian

and the extension to dynamical calculations is not straight forward. Here we
therefore

address the question of to what extent this technique might be applied to solve
the time-

dependent Schrodinger equation and to what extent resonant states contribute to
the

overall dynamical behaviour of the system. We have tested our approach against
conven-

tional methods for the case of hydrogen.

References

[1] 1. M. Drescher et al. Nauture, 419, 807 (2002)

CP 25

47

A simple parameter-free wavefunction

for the ground state of three-body systems

L.U. Ancarani1 and G. Gasaneo2

1Laboratoire de Physique Molśeculaire et des Collisions,

Universitśe Paul Verlaine - Metz, 57078 Metz, France

2Departamento de Fś³sica, Universidad Nacional del Sur and Consejo Nacional de

Investigaciones Cientś³¯cas y Tśecnicas, 8000 Bahś³a Blanca, Buenos Aires,
Argentina

The study of the structure and stability of Coulombic three-body systems
[m1m2m3],

with arbitrary masses mi and charges zi (i = 1; 2; 3), has been the subject of
many

investigations (see, e.g., the review [1]. Recently, we have proposed a
pedagogical, simple

and parameter-free wavefunction for the ground state of two-electron atoms [2].
The

proposal was then generalized [3] to more general atomic three-body systems in
which

one of the particles is positively charged (z3 > 0) and heavier than the other
two which

are negatively charged (z1 < 0; z2 < 0).

Let ºij = ¹ijzizj where ¹ij = mimj

mi+mj

(i 6= j = 1; 2; 3) are the reduced masses. In terms of

the interparticles coordinates r1 = r13; r2 = r23 and r12 (particle 3 is placed
at the origin

of the coordinates), the proposed wavefunction reads

ªGEN

ARG = NGEN

ARG eº13r1+º23r2 (1 + º12r12)

h

1 + c(r2

1 + r2

2)

i

;

where NGEN

ARG is the normalization constant and c is replaced by an analytical expression

in terms of (mi; zi) in order to minimize the mean energy of the ground state.

The wavefunction ªGEN

ARG : (i) has the same form for all systems; (ii) is parameter{free;

(iii) is nodeless; (iv) satis¯es, by construction, all two-particle cusp
conditions [4]; and (v)

yields reasonable ground state energies for several systems including the
prediction of a

bound state for H¡, D¡, T¡ and Mu¡. A wavefunction with all these
characteristics is

presently not available in the literature. The simplicity of ªGEN

ARG is such that analytical

expressions for the ground state energy can be derived. Hence, we have a useful
predictive

and simple analytical tool (which, to our knowledge, is not available in the
literature) to

estimate the energy, and therefore to study the stability, of exotic Coulombic
three{

body systems. In addition, our proposal is simple enough, but suąciently
accurate to be

used as a starting point in calculations of collision cross sections. Of course
due to its

simplicity, energy values cannot compete with those obtained with advanced
variational

wavefunctions which involve large number of basis functions. However, the latter
(i) do

not have a predictive character since they have to be optimized each time for a
given

three{body system.; (ii) in most cases, do not satisfy exactly Kato cusp
conditions.

For illustration, results will be shown for the several three-body systems.

References

[1] E. A. G. Armour, J.-M. Richard and K. Varga, Phys. Rep. 413, 1 (2005).

[2] L. U. Ancarani, K. V. Rodriguez and G. Gasaneo, J. Phys. B 40, 2695 (2007).

[3] L. U. Ancarani and G. Gasaneo, J. Phys. B 41, in press (2008).

[4] T. Kato, Comm. Pure Appl. Math. 10 151 (1957).

CP 26

48

(e; 3e) and (°; 2e) processes on helium:

interplay of initial and ¯nal states

L.U. Ancarani1, G. Gasaneo2, F.D. Colavecchia3 and C. Dal Cappello1

1Laboratoire de Physique Molśeculaire et des Collisions,

Universitśe Paul Verlaine - Metz, 57078 Metz, France

2Departamento de Fś³sica, Universidad Nacional del Sur and CONICET,

8000 Bahś³a Blanca, Buenos Aires, Argentina

3Centro Atśomico Bariloche and CONICET,

8400 S. C. de Bariloche, Rś³o Negro, Argentina

Information on correlations can be gained from the theoretical study of the
double ioniza-

tion of helium by electron impact ((e; 3e) experiments) [1]. Approximate wave
functions

are always used in cross section calculations since no exact wave function is
known for

either the scattering or the bound states. The resulting (e; 3e) cross sections
obtained

with diŽerent theoretical description of the initial and ¯nal states are not in
agreement

with each other. Moreover, when these are compared with absolute experimental
data, a

rather confusing picture emerges; this is the subject of many recent studies (as
discussed

and summarized in [2]). It has been mentioned throughout the literature (see,
e.g., [3])

that a balanced description of the initial and ¯nal two-electron states may play
a key role

in reproducing experimental (e; 3e) data. This issue is investigated here with a
systematic

study of double ionization cross sections of helium, by both electron and photon
impact.

For (e; 3e) processes, calculated diŽerential cross sections can be compared
with the high

energy absolute experimental data [4]. The two electrons ejected in the ¯nal
channel

at equal energy (10 eV) are modeled here with the "pure" C3 (or BBK) wave
function

[5]. For the initial channel we consider diŽerent sets of double bound wave
functions with

only angular correlation or with both angular and radial correlation. The
comparison with

the measurements allows us to see which of them are balanced when describing (e;
3e)

processes. Moreover, the photon impact (°; 2e) cross sections calculated in
diŽerent gauges

and with the same set of initial and ¯nal channel wave functions, indicate
whether the

wave functions are really "balanced" or not.

Our study of the (°; 2e) gauge discrepancies shows that the agreement with
absolute

(e; 3e) experimental data at 10+10 eV ejected energy obtained with simple
initial states

is fortuitous and can hardly be attributed to a balanced description with
respect to the

¯nal state. This result is further con¯rmed by an investigation of the ejected
energy

dependence. Moreover, it seems that the approximate C3 wave function is not
suitable

to describe suąciently well the double continuum of two electrons ejected at 10
eV.

References

[1] J. Berakdar, A. Lahmam-Bennani and C. Dal Cappello Phys. Rep. 374, 91 (2003)

[2] L.U. Ancarani, G. Gasaneo, F.D. Colavecchia and C. Dal Cappello, submitted
(2008)

[3] J. H. Macek and S. Jones, Rad. Phys. and Chem. 75, 2206 (2006)

[4] A. Lahmam-Bennani et al., Phys. Rev. A 59, 3548 (1999)

[5] C. R. Garibotti and J. E. Miraglia, Phys. Rev. A 21, 572 (1980); M. Brauner,
J.

Briggs and H. Klar, J. Phys. B 22, 2265 (1989)

CP 27

49

A three body approach to calculate the differential cross

sections for the excitation of H and He atoms by proton impact

R. Fathi2, E. Ghanbari-Adivi3, F. Shojaei Baghini1, and M.A. Bolorizadeh1

1Physics Department, Shahid Bahonar University of Kerman, Kerman, Iran

2Physics Department, Islamic Azad University, Kerman Branch, Kerman, Iran

3Physics Department, Isfahan University, Isfahan, Iran.

mabolori@mail.uk.ac.ir

A method based on the three-body formalism incorporated into the Born series
have been developed to

calculate the excitation of hydrogen and helium atom by proton impact at medium
and high energies. The

Faddeev type approaches to the scattering of charged particles are a
rearrangement of Born series. However,

the on shell transition matrix is not well defined by any method based on the
Lippmann-Schwinger

integral equation. We have developed a method incorporating the FWL formalism in
conjunction with

Born approximation to calculate the differential cross section for the
excitation of hydrogen and helium

atom by protons of energy 50 keV to 500 keV. In the case of hydrogen atom,
excitation to the final states

2s, 2p and 3s were included while for the case of atomic helium the calculations
were performed for the

final states 21S and 23S.

The excitation of atomic hydrogen is a three body process. However, the
excitation of helium is simplified

by an active model where the second electron is assumed frozen. The wave
function for the final state

of helium is chosen from literature[1]. We have also deduced a simple method
using a Slater type wave

function as:

Ã(r) = 0.854(1 − 1.15r/2) exp(−1.15r) + 0.488 exp(−1.6875r). (1)

The differential cross sections

for the excitation of helium

and hydrogen atoms are plotted

in figures 1(a) and 1(b),

respectively. In the case of

helium atom, the calculations

were performed using two different

wave functions for the

final state of the helium atom,

21S. One was the CHF wave

functions [1] and the other

one was the wave function

of equation 1. Figure 1(b)

shows the calculations for the

final state 2s and 2p of hydrogen.

The results are compared

with the experimental

work of Park and his coworkers

[2,3].

0.0 0.2 0.4 0.6 0.8

10 3

10 4

10 5

10 6

10 7

X 0.25

(a)

Differential Cross Section for Excitation (a.u) CM Scattering Angle(mrad)

Exp. Results by Park [2]

Present Work (CHF

wave function)

Present Work

(A Simple Model)

0.0 0.2 0.4 0.6 0.8 1.0

10 4

10 5

10 6

10 7

10 8

(b) Exp. Results by Park [3]

Present Work

CM Scattering Angle (mrad)

Figure 1. The excitation cross section for (a) helium and (b) hydrogen

atom by proton impact at 50keV. The experimental results

are from Park and co-workers.

Acknowledgement:

The authors would like to thank Dr. M. Shojaei for his help in the preparation
of the manuscript.

References

[1] G. N. Bhattacharya and G. S. Kastha, J. Phys. B: At. Mol. Phys. 14, (1981),
3007

[2] T.J. Kvale, et al, Phys. Rev. A 32 (1985) 1369

[3] J.T. Park, et al, Phys. Rev. A 21 (1980) 751

CP 28

50

CP 29

51

CP 30

52

CP 31

53

Ionization and Dissociative Ionization of Adenine

Molecules by Electron Impact near Threshold

O.B.Shpenik, A.N.Zavilopulo

Institute of Electron Physics, Ukr. Nat. Acad. Sci.

21 Universitetska str., Uzhgorod 88017, Ukraine

E-mail: an@zvl.iep.uzhgorod.ua

An increased interest to the studies of biomolecules by traditional methods of
physics of

electron collisions is explained by the significance of these molecules in
modern life. Here

we report on a study of the features of the process of ionization, including
dissociative

ionization, of adenine molecules under electron impact, accompanied by the
formation of

ionized products of reaction. The experimental setup, used for the investigation
of partial

cross-sections of dissociative ionization of molecules by electron impact, is
described in

detail in a number of our papers (See, e. g., [1]). The setup is constructed on
the base

of a monopole mass spectrometer with an electron ionizer and a multichannel
molecule

source of effusion type. The ionic products of dissociative ionization,
separated by the

high-frequency field of the analyser, were detected by a channeltron. The
scanning of

the ionizing electron energy and data acquisition were performed using a
computer and

a specially developed software. The duration of one measurement cycle was chosen
in

such a way that the number of pulses of the useful signal in the maximum of the
energy

dependence curve should not be less than 104. In short, the measurement
technique

was the following. At first the adenine molecule mass spectrum was measured at
the

ionizing electron energy of 40 and 70 eV , then for each fragment the
dissociative ionization

function was measured. The mass scale was calibrated using Ar, Kr and Xe, and a
special

procedure of polynomial fitting of the threshold part of the ionization
cross-section [2] was

used to determine the appearance potentials of various ion fragment groups. The
fragment

appearance potentials were determined from the threshold dependences of the ion
yield.

We also studied temperature dependences of intensities of the ion fragments of
the initial

molecule in the temperature range 343−480 K. The measurement technique was
reduced

to the measurement of mass spectra at various temperatures at Eion = 50 eV .
From the

temperature dependences, the evolution of the fragment formation could be traced
and the

effect of temperature on the dissociative ionization could be observed. We have
measured

energy dependences of the total cross-section of the adenine molecule ionization
as well as

the cross-sections of dissociative ionization of formation of the fragment ions.
We have also

determined the appearance potentials for the fragment ions with m/e = 43, 54,
81, 108.

This work was supported in part by the CRDF Grant ]UKC − 2832 − UZ − 06.

References

[1] A.N. Zavilopulo, O.B. Shpenik, V.A. Surkov, Anal.Chim.Acta 573-74, 427-431
(2006).

[2] T. Fiegele, at.al, J.Phys.B: Atom. Mol. Opt. Phys. 33, 4263-4269 (2000).

CP 32

54

CP 33

55

Charge transfer in collision of protons with water molecule

and atomic helium at high energy

S. Houamer1, Y. Popov2 , C. Champion3 and C. Dal Cappello3

1 Laboratoire de Physique Quantique et Systèmes dynamiques, Département de
physique,

Faculté des sciences, Université Ferhat Abbas, Sétif, 19000 , Algeria

2Nuclear Physics Institute, Moscow state University, Moscow 119899, Russia

3Laboratoire de Physique Moléculaire et des Collisions, Institut de Physique, 1
Boulevard

Arago, 57078 Metz Cedex 3, France

Charge transfer process in collision of protons with water molecule and helium
is

investigated at high energy using a first Born model in which different reaction
mechanisms

are considered. A sophisticated configuration interaction wave function is used
to describe

helium atom while the projectile is described by a plane wave.

The process is investigated for H20 molecule in the frozen core model where the
target is

described by a single center wave function successfully used formerly in
ionization

process. The SDCS is calculated for both targets at high impact energy . The

TCS is than deduced by direct integration over solid angle in an energy range
between 0.1

and 3 MeV. The results are finally compared with experiments in order to check
the

validity of the model.

E MeV i = 1.4

0 ,1 1 1 0

1 E - 2 3

1 E - 2 2

1 E - 2 1

1 E - 2 0

1 E - 1 9

1 E - 1 8

1 E - 1 7

1 E - 1 6

1 E - 1 5

1 E - 1 4

1 E - 1 3

1 E - 1 2

0 ,1 1 1 0

1 E - 2 7

1 E - 2 6

1 E - 2 5

1 E - 2 4

1 E - 2 3

1 E - 2 2

1 E - 2 1

1 E - 2 0

1 E - 1 9

1 E - 1 8

1 E - 1 7

1 E - 1 6

1 E - 1 5

H 2 O

TCS (cm

2

)

P r o to n e n e r g y (M e V )

H e

Fig. 1 Absolute TCS for electron capture in proton collision with H2O and He.

Experimental data are taken from [1] for H2O and [2] for He.

It should be noted that for a water molecule three more integrations must be
performed to

average over the random orientation of the molecular target.

[1] J. H. Toburen, M. Y. Nakal and R. A. Langley, Phys. Rev. 171, 114 (1968)

[2] I. Mancev, V. Mergel and L. Schmidt, J. Phys. B 36 2733 (2003)

CP 34

56

Ar(3p54p) states excitation in low-energy

Ar-Ar collisions

S.Yu. Kurskov and A. S. Kashuba

Department of Physics and Engineering, Petrozavodsk State University

Lenin 33, 185910 Petrozavodsk, Russia

E-mail: kurskov@psu.karelia.ru

The present work is devoted to study of Ar(3p5 4p) states excitation in binary
low-energy

Ar{Ar collisions. The purpose of this work is the research of mechanisms of
atomic levels

excitation at collision energies that corresponds of the adiabatic approximation
conditions.

The results of the experimental investigation of excitation cross sections of Ar
I 4p0[1/2]1,

4p0[3/2]1, 4p0[3/2]2 and 4p[3/2]2 levels in the collision energy range from
threshold up to

500 eV (centre of mass system) and degree of polarization for 4s[3/2]0

2 ¡ 4p0[1/2]1 and

4s[3/2]0

2 ¡ 4p[3/2]2 transitions in this energy range are represented.

The measurements of the cross sections at interaction of an atomic beam with a
gas target

were carried out by optical methods on setup, controlled by computer. The
measurement

procedure was described in detail in the work [1].

The obtained results demonstrate that the polarization degree of emission
signi¯cantly

depends on collision energy { when the latter goes up, the former changes its
sign. The fact

that the sign of the polarization degree changes, as well as does interaction
energy, proves

that the mechanism of level population changes too [2]. For instance, since the
angular

momentum of 4p0[1/2]1 excitation level is equal to 1, the positive polarization
degree

shows that the magnetic sublevel ¾0, that is zero momentum projection onto
internuclear

axis of the Ar2 quasimolecule, is mostly populated. Negative polarization
degree, in its

turn, means that there is a dense population at magnetic sublevels ¾1,
corresponding to

§1 projections. Therefore, according to the data obtained, if collision energy
is higher

than 400 eV, the population at the mentioned above level is determined by §g ¡
§0

g

transactions. If collision energy is equal to or lower than 300 eV, level
population is guided

by §g¡Śg transactions due to radial coupling of even terms of the Ar2
quasimolecule. It is

important to note that since output §g terms of the Ar2 quasimolecule are
actually double

excited terms, supposedly, the other interacting atom is excited too. This fact
agrees with

Wigner's law (system spin unchanged at collision) and with the research results
described

in works [3, 4]. The diabatic molecular orbital diagram for homonuclear system
[5] and

measurement results of the polarization of emission lead to the following
conclusion: if

collision energy is less or equal to 300 eV, the population of 4p0[1/2]1 level
is determined

by 4p¾ ¡ 4p¼ transactions due to rotational coupling at small nuclear distances.
In case

of higher energies, the population is governed by 5f¾ ¡ 5d¾ transactions due to
non-

adiabatic radial coupling.

Reference

[1] S.Yu. Kurskov, A.D. Khakhaev, Czech. J. Phys. 56, B297 (2006).

[2] K. Blum, Density Matrix Theory and Applications (N.Y., Plenum Press, 1981).

[3] P.J. Martin, G. Riecke, J. Hermann et al., J. Phys. B11, 1991 (1978).

[4] L. Moorman, V. van Hoegaerden, J. van Eck et al., J. Phys. B20, 6267 (1987).

[5] M. Barat, W. Lichten, Phys. Rev. A6, 211 (1972).

CP 35

57

Low-energy electron scattering from calcium

S. Gedeon and V. Lazur

Department of Theoretical Physics, Uzhgorod National University, 88000, Ukraine

E-mail: vfg-vik@yandex.ru

The B-spline R-matrix method (BSR) [1] is used to investigate the integrated
cross sec-

tions (ICS) of elastic electron scattering from neutral calcium in the ultra-low
energy

range from threshold to 0.5 eV. The close-coupling expansion includes 39 bound
states of

neutral calcium, covering all states from the ground state to 4s8s 1S. The
computational

model was described in detail in [2]. Brie°y, we generate an accurate target
description by

using multicon-¯guration expansions, accounting for both valence and
core-valence corre-

lations. Very importantly, we use term-dependent valence orbitals, which are
optimized

individually for the various states of interest. We also account for relaxation
of the core

orbitals, due to the deep penetration of the 3d orbital. As a result, we have a
set of

normalized orthogonal one-electron orbitals for each state, but the orbitals
from diŽerent

sets do not form an orthonormal basis.

In this work we are compared the total and partial electron-impact cross
sections from

Ca in the ultra-low energy region, calculated in two diŽerent R-matrix
approaches: the

present BSR method and R-matrix with pseudostates method (RMPS) [4]. As seen
from

our calculations, basic diŽerence between the cross sections in two R-matrix
approaches

comes mainly from the dominated 2Po partial wave. In the same time, partial
cross

sections for the 2Se and 2De partial waves in these two methods practically
coincide.

In present work we also are compared the total BSR39 and RMPS cross sections
with

experimental data of Romaniuk et al [3]. Overall, the agreement between both
R-matrix

(BSR39 and RMPS) results and the experimental data [3] is satisfactory, although
a few

discrepancies remain. We are compared 2Se, 2Po and 2De partial eigen-phases of
electron-

impact scattering from Ca at low energies region between most recent
calculations: BSR39

(the present calculation), RMPS [4] and method of static-exchange formalism [5].
Again,

the largest discrepancy between diŽerent method was found for 2Po partial wave.

References

[1] O. Zatsarinny, Comput. Phys. Commun. 174, 273 (2006)

[2] O. Zatsarinny et al., Phys. Rev. A, 74, 052708 (2006)

[3] N.I. Romanyuk, O.B. Shpenik, I.P. Zapesochnyi, Pis'ma Zh. Eksp. Teor. Fiz.,
32,

472 (1980) [JETP Lett. 32, 452 (1980)]

[4] K. Bartschat and H.R. Sadeghpour, J. Phys. B. 36, L9 (2003)

[5] J. Yuan, Zh. Zhang, Phys. Rev. A 42, 5363 (1990)

CP 36

58

Ab initio calculation of H+He+ electron transfer cross

sections

J. Loreau1, M. Desouter-Lecomte2, F. Rosmej3 and N. Vaeck1

1Service de Chimie Quantique, ULB, Brussels, Belgium

2LCP, Universit´e de Paris XI, Orsay, France

3Universit´e de Provence et CNRS, Centre St. J´erˆome, PIIM, Marseille, France

E-mail: jloreau@ulb.ac.be

Charge transfer mechanisms during collision processes between ions and neutral
atoms

or molecules have recently received renewed attention, due to their role in the
analysis of

laboratory and astrophysical plasmas.

To understand the physical processes that underlie plasma transport in
magnetically

confined plasmas, spectroscopic methods have turned out to be very effective.
One of the

most powerful of these methods is based on the space and time resolved
observation of

line emission from impurity ions. However, under real experimental conditions of
fusion

plasmas, the impurity ions interact with the plasma background H/D which leads
to a

change of the radial distribution of the impurity ions due to charge exchange
processes [1].

As helium is of particular interest for magnetically confined fusion research
(production

from recombining alpha particles, ash transport), we calculate the charge
exchange cross

sections between He+ and the H/D background for numerous channels at low
energies (as

the electron temperature of divertor plasmas is much below an atomic unit). This
implies

computational difficulties as a fully quantum mechanical description is needed.

We have used a quasi-molecular approach of the ion-atom collision based on the
use of

conventional quantum-chemistry ab initio methods to obtain the potential energy
surfaces

as well as the radial and rotational coupling matrix elements of the
quasi-molecule HeH+.

The main problem encountered in this part of our work is the large number of
excited

molecular states that need to be taken into account, necessitating the
introduction of a

new basis of molecular orbitals.

A wave packet method is used to treat the curve-crossing dynamics resulting from
the

failure of the Born-Oppenheimer approximation. A Gaussian wave packet is
prepared

in the entrance channel and propagated on the coupled effective channels. The
collision

matrix elements are computed from an analysis of the flux in the asymptotic
region

by using properties of absorbing potentials, giving access to the charge
exchange crosssections

[2]. We study different propagation methods, the influence of the rotational

couplings on the cross section as well as the problem of the origin-dependence
of the

radial and rotational couplings.

References

[1] F. B. Rosmej, E. Stamm and V. S. Lisitsa. Europhys. Lett., 73, 342 (2006).

[2] E. Balo¨ıtcha, M. Desouter-Lecomte, M.-C. Bacchus-Montabonel and N. Vaeck.
J. Chem.

Phys. 114, 8741 (2001).

CP 37

59

TDCS for inner-shell (e, 2e) processes on alkali and alkali

earth atoms Na, K, Be, Mg and Ca.

G. Purohit1, U Hitawala2 and K K Sud1, 2

1Department of Basic Sciences, Sir Padampat Singhania University

Bhatewar, Udaipur-313601, India

2Department of Physics, College of Science Campus,

M.L.S. University, Udaipur-313002, India

The study of electron impact ionization of atoms and molecules has been of
interest, since the

early days of atomic and molecular physics, since the kinematics of this process
are easily

controlled, and the electrons or ions resulting from the reaction can be
observed with relative

ease. Since the first coincident measurement of (e, 2e) process on atoms by
Erhardt et al[1] and

Amaldi et al[2] extensive theoretical and experimental investigations have been
done to

measure the TDCS. A number of different theories have been developed, ranging
from firstorder

Born calculations (and variations therein) which are successful at high incident
energies

and asymmetric geometries [3] to second and higher order Born calculations,
which are

successful at higher energies in more complex scattering geometries [4].
Variants on these

models include distorted wave Born approximations (DWBAs) that have achieved
success

down to intermediate energies [58]. Recently U Hitawala et al [9] have
calculated the (e, 2e)

triple differential cross section for alkali atoms Na and K and alkali earth
atoms Mg and Ca.

We present in this communication the results of our calculation of triple
differential cross

section (TDCS) for inner-shell (e, 2e) processes on alkali Na and K and alkali
earth Be, Mg

and Ca atoms. We discuss the effects of incident electron energy, distortion,
nuclear charge,

polarization, post collisional interaction etc. for the alkali and alkali earth
targets investigated

by us.

References

[1] Ehrhardt H., Schulz M.,Tekaat T.and Willmann K. ,, Phys. Rev. Lett. 22, 89
(1969)

[2] Amaldi U., Egidi A., Marconnero R., and Pizzela G., Rev.Sci.Instrum. 40,

1001 (1969).

[3] Duguet A, Cherid M, Lahmam-Bennani A, Franz A and Klar H 1987 J.Phys.B: At.

Mol. Phys. 20 6145.

[4] Byron F.W. and Joachain C.J. 1989 Phys. Rep.179 211.

[5] Zhang X, Whelan C.T. and Walters H.R.J. 1990 J.Phys. B:At. Mol.Opt.Phys.23
L509.

[6] Rioual S., Pochat A., Gelebart F., Allan R.J., Whelan C.T. and Walters
H.R.J., 1995.

J.Phys.B:At.Mol.Opt.Phys. 28 5317

[7] Rosel T, Roder J, Frost L., Jung K,Ehrhardt H.,Jones S.and Madison D.H. 1992

Phys.Rev. A46 2539

[8] Reid R.H.G., Bartchat K. and Raekar A 1998 J. Phys. B: At. Mol.Opt.Phys. 31
563.

[9] Hitawala U, Purohit G and Sud K K, J. Phy. B: At. Mol. Opt. Phys. (In
Press), 2008

CP 38

60

The relativistic J-matrix method in scattering of

electrons from model potentials and small atoms

P. Syty

Department of Theoretical Physics And Quantum Informatics

Gda´nsk University of Technology

Narutowicza 11/12, 80-952 Gda´nsk, Poland

e-mail: sylas@mif.pg.gda.pl

The J-matrix method is an algebraic method in quantum scattering theory. It is
based on

the fact that the radial kinetic energy operator is tridiagonal in some suitable
bases. Nonrelativistic

version of the method was introduced in 1974 by Heller and Yamani [1] and

developed by Yamani and Fishman a year after [2]. Relativistic version was
introduced

in 1998 by P. Horodecki [3].

The main advantage of the method is that it allows to calculate phase shifts for
many

projectile energies with relatively small computational time. Also, the
non-relativistic

limit in relativistic calculations is properly achieved. This fact was expected,
since the

basis sets used in relativistic calculations satisfied the so called kinetic
balance condition.

Some preliminary applications of relativistic J-matrix method to scattering have
been

performed for some square-type potentials [4], using the newly developed Fortran
95 code

JMATRIX [5]. These tests proved that the method correctly describes the
scattering

process.

Since these times, the JMATRIX code has been greatly extended and thoroughly
tested.

In the present work we applied the code (in both non-relativistic and
relativistic versions)

to calculate some scattering properties of electrons scattered from more complex

potentials, i.e. truncated Coulomb, Yukawa and Lenard-Jones potentials and more.
In its

primary version, the JMATRIX program allowed for applying scattering potentials
in analytical

forms only. Now the code has been extended, so it allows for applying scattering

potential given in any numerical form, i.e. taken from the GRASP92 code [6].

In conclusion, we present the calculated scattering phase shifts and cross
sections for

many energies of the incident electrons, in cases of the analytical potentials
mentioned

previously, as well as the numerical potentials of some small atoms. Also, we
illustrate

the convergence process and describe some limitations of the method.

References

[1] E. Heller, H. Yamani, Phys. Rev. A 9, 1201 (1974)

[2] H. Yamani, L. Fishman, J. Math. Phys. 16, 410 (1975)

[3] P. Horodecki, Phys. Rev. A 62, 052716 (2000)

[4] P. Syty, TASK Quarterly 3 No. 3, 269 (1999)

[5] P. Syty, http://aqualung.mif.pg.gda.pl/jmatrix/

[6] F.A. Parpia, C. Froese Fischer, I.P. Grant, Comput. Phys. Commun. 94, 249
(1996)

CP 39

61

Multichannel atomic scattering and

confinement-induced resonances in waveguides

V.S. Melezhik1

,

, S. Saeidian2, P. Schmelcher2

,

3

1Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear
Research,

Dubna, Russia

2Physikalisches Institut, Universit¨at Heidelberg, Philosophenweg 12, 69120
Heidelberg,

Germany

3Theoretische Chemie, Institut f¨ur Physikalische Chemie, Universit¨at
Heidelberg, INF

229, 69120 Heidelberg, Germany

E-mail: melezhik@theor.jinr.ru

Pair atomic collisions in restricted geometry principally differ from the
conventional two-

body free-space scattering. The restricted geometry leads to quantization of the
atomic

motion in the direction of confinement. Another nontrivial effect for two
distinguishable

quantum particles in a transverse harmonic trap is the confinement induced
nonsepara-

bility of the center-of-mass (CM) and the relative motions. These effects can
have exper-

imental mesoscopic developments for ultracold atoms in optical traps and atomic
chips.

However, only simple analytical estimates were performed for the special case
when iden-

tical atoms occupy lowest quantum states of a confining trap. In this
zero-energy limit

the total atom-atom reflection has been predicted for the case of
confinement-induced res-

onance (CIR)[1]. The origin of the CIR is a virtual transition from the ground
transverse

state of the confining potential to the closed excited state during the
collision[2].

We have investigated what happens if the energy range of colliding atoms
encompasses

several quantum states of the confining potential[3]. The developed method
permits

to analyze the transverse excitations/deexcitains and optimal conditions for
avoiding

decoherence-inducing mechanisms at atomic collisions in waveguides. Special
attention

was paid to the analysis of the CIRs for nonzero collision energies in the
multimode

regimes. We have suggested a nontrivial extension of the CIRs theory developed
so far

only for the single-mode regime at zero-energy limit. We have also fully took
into account

the coupling between the CM and the relative motions in case of distinguishable
atoms[4].

Specifically we explore in detail the recently discovered[5] dual CIR which is
based on a

destructive interference mechanism leading to complete transmission in the
waveguide

although the corresponding scattering in free space-exhibits strong s and p wave
scatter-

ing. Possible applications include, e.g., cold and ultracold atom-atom
collisions in atomic

waveguides and electron-impurity scattering in quantum wires.

References

[1] M. Olshanii, Phys. Rev. Lett. 81, 938 (1998).

[2] M.G. Moore, T. Begeman, and M. Olshanii, Phys. Rev. Lett. 91, 163201 (2003).

[3] S. Saeidian, V.S. Melezhik, and P. Schmelcher, Phys. Rev. A 77, 042721
(2008).

[4] V.S. Melezhik, J.I. Kim, and P. Schmelcher, Phys. Rev. A 76, 053611 (2007).

[5] J.I. Kim, V.S. Melezhik, and P. Schmelcher, Phys. Rev. Lett. 97, 193203
(2006).

CP 40

62

Excitation of forbidden 4d95s2 2D5/2 ! 4d105s 2P3/2

transition in In2+ ion at electron-In+ ion collisions

E.Ovcharenko, A.Gomonai, A.Imre, Yu.Hutych

Institute of Electron Physics, Ukrainian National Academy of Sciences,

Universitetska 21, 88017 Uzhgorod, Ukraine, e-mail: dep@mail.uzhgorod.ua

Here we report on the results of experimental investigation of excitation of the
4d95s2 2D5/2 !

4d105p 2P3/2 transition in In2+ ion at electron-In+ ion collisions, which is
two-electron

dipole forbidden in pure LS-coupling. The experiment was carried out by a photon
VUV

spectroscopy method using a crossed electron and ion beam technique. The
specific features

of the experimental technique for studying the processes occurring at the
inelastic

slow-electron collisions with indium ions are described in detail in [1].

The energy dependence of the effective excitation cross section for the In2+
spectral line

( 185.0 nm wavelength) was studied from the excitation threshold up to 100 eV
according

to the following reaction scheme:

e + In+(4d105s2) 1So ! In2+(4d95s2) 2D5/2 + 2e

#

In2+(4d105p) 2P3/2 + h ( 185.0 nm)

A distinct structure in the above energy dependence within the energy range from
the

threshold (Eex = 33.18 eV ) of the 4d95s2 2D5/2 level up to 50 eV was observed.
Since

indium ion is a multielectron atomic system with pronounced correlation and
relativistic

effects, this leads to strong mixing of both the ionic levels and the
corresponding

autoionizing states (AIS).

The observed structure in the energy range from the threshold up to 40 eV may be

assigned to the contribution of the highest 4d95s2(2D3/2)np,mf AIS as well as to
that of

the cascade transitions from the 4d106s−, 4d105d− and 4d106p− levels, while the
structure

in the energy range 40 − 45 eV to those from the 4d95s5p− levels of In2+ ion
[2,3]

and decay of the In+ ion autoionizing states converging to the In2+ states. A
broad

maximum above 50 eV is observed, which, we believe, reflects the mechanism of
the

direct d-ionization process in In+ ion.

The result obtained, besides the fundamental significance, is of applied
importance, since

In+ ion is isoelectronic to Cd atom, and the transition in In2+ ion at 185.0 nm
is similar

to the well-known Cd+ 4d95s2 2D5/2 ! 4d105p 2P3/2 laser transition at 441.6 nm
in the

He-Cd+ laser. As shown in [4], this radiative transition at 185.0 nm is the best
candidate

for lasing in vacuum ultraviolet range.

References

[1] A.Gomonai, E.Ovcharenko, A.Imre, Yu.Hutych, Nucl. Instr. and Meth. in Phys.
Res.

B 233, 250-254 (2005).

[2] D.Kilbane, J-P.Mosnier, E.T.Kennedy, J.T.Costello, P. van Kampen, J. Phys.
B: At.

Mol. Opt. Phys. 39, 773-782 (2006).

[3] K.S.Bhatia, J. Phys. B: Atom. Molec. Phys. 11, 2421-2434 (1978).

[4] R.A.Lacy, A.C.Nilsson, R.L.Byer, J. Opt. Soc. Am. B 6, 1209-1216 (1989).

CP 41

63

The electron aąnity of Tungsten

A. O. Lindahl1, P. Andersson1, C. Diehl2, O. Forstner3, K. Wendt2, D. J. Pegg4
and

D. Hanstorp1

1Department of physics, University of Gothenburg, SE-412 96 Gothenburg, Sweden

2Institut fÄur Physik, Johannes Gutenberg-UniversitÄat, Mainz, 55099 Mainz,
Germany

3Institut fÄur Isotopenforschung und Kernphysik, VERA-Laboratory, University of

Vienna, Kavalierstrakt A-1090 Wien

4Department of physics, University of Tennessee, Knoxville, Tennessee 37996, USA

E-mail: anton.lindahl@physics.gu.se

An improved value of the electron aąnity of Tungsten will be presented. The
threshold

for photodetachment of W¡ forming neutral W in the ground state was investigated
by

measuring the total photodetachment cross section. The electron aąnity was
obtained

from a ¯t of the Wigner law in the threshold region.

The experiment showed a photodetachment signal below the threshold associated
with

detachment from the ground state negative ions. This observation indicate the
existence

of a previously unobserved bound excited state in W¡.

The experiment was performed using the ion beam apparatus GUNILLA (GÄoteborg
Uni-

versity Negative Ion Linear Laser Apparatus). This apparatus, which previously
has been

used to investigate light negative ions, has been redesigned in order to obtain
a higher

mass resolution and better transmission. The W¡ measurement is an example of the
high

mass capabilities of the new apparatus. The ion optical design and performance
of the

apparatus will be described in some detail.

CP 42

64

High resolution measurements of molybdenum

L-shell satellites and hypersatellites excited by

oxygen and neon ions

M. Czarnota1, D. Banaśs1, M. Berset2, D. Chmielewska4, J.-Cl. Dousse2, J.
Hoszowska2,

Y.-P. Maillard2, O. Mauron2, M. Pajek1, M. Polasik3, P. A. Raboud2, J.
Rzadkiewicz4,

K. SÃlabkowska3, Z. Sujkowski4

1Institute of Physics, Jan Kochanowski University, 25-406 Kielce, Poland

2Department of Physics, University of Fribourg, CH-1700 Fribourg, Switzerland

3Faculty of Chemistry, Nicolaus Copernicus University, 87-100 Toruśn, Poland

4SoÃltan Institute for Nuclear Studies, 05-400 Otwock-śSwierk, Poland

The observation of L-shell hypersatellites of molybdenum LŽ1;2 (L3!M4;5) and L¯1

(L2!M4) x-ray transitions excited in ion-atom collisions are reported. The
high-resolution

measurements of x-ray satellites and hypersatellites emitted from multiply
ionized molyb-

denum give access to study the ¯ne details of a structure of multi-vacancy
states in mid-Z

atoms. Such experiments are important for testing the atomic structure
calculations, in

particular, the relativistic multi-con¯guration Dirac-Fock (MCDF) approach,
including

the Breit and QED corrections. In this way the structure calculations can be
tested for

excited atoms having up to several vacancies in inner shells.

The high-resolution measurements of Mo LŽ1;2 and L¯1 x-ray satellites excited by
oxygen

and neon ions were performed at the Philips cyclotron in the Paul Scherrer
Institute (PSI)

in Villigen, Switzerland, using O6+ and Ne6+ ions with energy 278.6 MeV and
177.9 MeV

respectively. The excited L-x-rays were measured with a high-resolution
diŽraction von

Hamos spectrometer [1] having an instrumental energy resolution of 0.6 eV for
studied

x-rays. The absolute energy calibration of the spectrometer was about 0.3 eV
[2].

In order to interpret the observed structure of LŽ1;2 x-ray satellites and
hypersatellites

and L¯1 satellites in molybdenum the relativistic MCDF calculations [3] were
performed

for multi-vacancy con¯gurations (L¡lM¡mN¡n) expected to be excited in collisions
with

O and Ne ions. These included the x-ray diagram (L¡1), satellite (L¡1M¡mN¡n),
hy-

persatellite (L¡2) and hypersatellite satellite (L¡2M¡mN¡n) transitions, with m
and n

indicating a number of vacancies in the M- and N-shell in the initial state.

To our knowledge, this is the ¯rst experimental observation of a direct ion
excitation of

the L-shell hypersatellites in molybdenum, which is, additionally, clearly
interpreted by

a complex MCDF calculations performed revealing their internal structure
corresponding

to the multi-vacancy (L¡2N¡nM¡m) con¯gurations.

References

[1] J. Hoszowska et al., Nucl. Instr. and Meth. A376, 129 (1996)

[2] M. Czarnota et al., Nucl. Instr. and Meth. B205, 133 (2003)

[3] M. Polasik, Phys. Rev. A52, 227 (1995)

CP 43

65

Electron-impact scattering on boron

L. Bandurina1, V. Gedeon2

1Institute of Electron Physics, Uzhgorod, 88026, Ukraine

2Department of Theoretical Physics, Uzhgorod National University, 88000, Ukraine

E-mail: vfg-vik@yandex.ru

The B-spline R-matrix (BSR) method [1] is used to investigate electron-impact
scattering

on neutral boron over an energy range from threshold to 60 eV. A
multi-configuration

Hartree-Fock method with nonorthogonal orbitals is employed to generate an
accurate representation

of the target wavefunctions. The present close-coupling expansion includes the

8 bound states of neutral boron derived from the 1s22s22p, 1s22s2p2, 1s22s23l (l
= 0, 1, 2)

configurations, plus twenty pseudo-states. The primary difficulties in the
target structure

and coupling to the target continuum for B arise from the 2s2p2 configuration.
The

orbitals in this configuration have been corrected here through configuration
interaction

with the 2s2pnl and 2p2nl sequences. These same pseudostate expansions also
provide

for coupling of 2s2p2 configuration with the target continuum.

Results for angle-integrated and angle-differential cross sections and effective
collision

strengths are presented for important transitions from the ground state 2s22p
2Po and

the excited 2s2p2 4P and 2s23s 2S states. Results for angle-integrated cross
sections are

compared with experimental data Kuchenev and Smirnov [2] and predictions from
other

R-matrix calculations Marchalant and Bartschat [3] and Balance et al [4]. Our
predictions

for the angle-integrated cross sections show some discrepancies with those from
previous

calculations carried out with the standard R-matrix with pseudostates (RMPS)
approach

in a similar scattering model [3] and [4]. These discrepancies are mostly due to
the different

target descriptions, with the present one giving some better agreement with
experiment

[5] for energy levels. The excitation cross sections exhibit prominent resonance
structures

in the low-energy region. The energy positions, widths, and classifications for
the detected

resonances are presented.

References

[1] O. Zatsarinny, Comput. Phys. Commun. 174, 273 (2006)

[2] A.K. Kuchenev, Yu.M. Smirnov, Opt. spectrosc. 51, 116 (1981)

[3] P.J. Marchalant and K. Bartschat, J. Phys. B 30, 4373 (1997)

[4] C.P. Ballance, D.C. Griffin, K.A. Berrington and N.R. Badnell, J. Phys. B
40, 1131

(2007)

[5] NIST Atomic Spectra Database, http://physics.nist.gov

CP 44

66

Observation of He He collisions using

the anticrossing method

E. Baszanowska1, R. Drozdowski1, P. Kaminski1, G. von Oppen2

1University of Gdansk, Institute of Experimental Physics, Wita Stwosza 57,

80-952 Gdansk, Poland

2Technische Universitat Berlin, Hardenbergstr. 36, D - 110623 Berlin, Germany

Excitation of He atoms by He+-ion impact has been analyzed for a large range of
projectile

energies. Of particular interest was the intermediate energy region, where the
velocity of

the projectiles is comparable with the Bohr velocity of the bound electrons of
the He-target

atoms. It was shown [1] that it is this transition region where the excitation
mechanism

changes from a process, which essentially can be described within the framework
of the

molecular orbital model, to a process describable using the Born approximation.
In this

transition region, saddle dynamics [2] and electron promotion based on the
atomic Paul

trap mechanism [3] are suitable to describe this excitation process.

In the present investigations we analyzed the excitation of He atoms by He-atom
impact

in the intermediate-energy range. The post-collisional states contain components
with

different parity. Therefore the charge distribution of the electronic clouds of
the excited

atoms can be asymmetric. The charge distribution was determined by using
anticrossing

spectroscopy. By applying electric fields to the collision volume the singlet
and triplet 1snl

states with l ≥ 2 can be tuned to near degeneracy. Due to the spin-orbit
coupling, the

Stark substates with the same rotational and reflection symmetry are strongly
mixed. This

mixing gives rise to the formation of anticrossings which could be detected as
resonancelike

variations of the intensity of the emitted spectral lines. In the experimental
setup, the

intensity of the selected spectral lines emitted by the collisionally excited He
atoms in a

direction perpendicular to the crossed beams is measured as a function of an
electric field

applied parallel and antiparallel to the projectile beam. Then, if the
population numbers

of the anticrossing singlet and triplet levels are not equal, an anticrossing
intensity peak

is observed. The amplitudes of these anticrossing peaks provide information
about the

charge distribution of the collisionally excited state. Additionally, the
spectrum of the

emitted light was measured for various selected values of the field strength.

The symmetric He-He collision system is composed of four equivalent electrons
and two

identical nuclei. In collisions, the target atom as well as the projectile atom
can be excited.

Singlet states are populated by direct excitation, but triplet states only by
electron

exchange. The evolution of the He-He system is expected to be more complex than
the

He+-He evolution, where only one electron is promoted on the two-centre
potential of the

He+ ions. But our measurements show that for intermediate-energy He-He
collisions the

excited He-target atoms possess electric dipole moments, that is, the charge
distributions

of the electronic clouds are asymmetric. Since in the He+-He collisions this
asymmetry is

mainly due to a coherent population of the l ≥ 2 states, we conclude that the
Paul-trap

mechanism probably plays an important role also in these He-He collisions.

This work was supported by the BW grants of the University of Gdansk:
5200-5-0048-8 and 5200-5-0483-8

[1] M. Busch, R. Drozdowski, Th. Ludwig and G. von Oppen, J. Phys. B 37, 2903
(2004)

[2] J. M. Rost, J.S. Briggs, J. Phys. B 24, 4293 (1991).

[3] G. von Oppen, Europhys. Lett. 27, 279 (1994)

CP 45

67

Spin-exchange cross sections at the interaction

between ground state rubidium and metastable

helium atoms

V.A.Kartoshkin, S.P.Dmitriev, and N.A.Dovator

A.F.IoŽe Physico-Technical Institute, Russian Academy of Sciences,

Polytechnical str.26, 194021 St.-Petersburg, Russia

E-mail: victor.kart@mail.ioŽe.ru.

At the interaction between spin-polarized excited atom and ground state alkaline
metal

atom in gas discharge elastic and inelastic processes take place simultaneously.
In such

a case these two processes in°uence on each other giving rise to a change of the
cross

section's value for the elastic process. It means, that besides the
chemiionization of the

ground state atom at the expense of the atom's excitation energy (inelastic
process), an

exchange of electrons was shown to be possible without a great depolarization
(s.c. spin

exchange, or elastic process) [1].

Up to the present there was only one experimental work where the spin-exchange
and

chemiionization cross sections were measured . The experiment has been done for
He*

-Cs system [1] .

In order to determine interesting us cross sections we have to separate two
simultaneously

occurring spin-dependent processes. In the experiment on optical polarization of
the

helium metastable atoms these atoms may be aligned or oriented along a static
magnetic

¯eld. It can be shown that the rates of the decay of the orientation < SHe >z
and

alignment < QHe >zz of metastable atoms depend on chemiionization and
spin-exchange

processes as follows

1=¿or = ¼ąfor = N(1/3 Cci + 1/2 Cse),

1=¿al = ¼ąfal = N(1/3 Cci + 3/2 Cse),

here N is the alkali metal atom concentration, Cci and Cse - are the
chemiionization

and spin-exchange rate constants, ąfor and ąfal are the widths of the
orientation and

alignment signals, 1=¿i is the rate of the decay of the metastable atom's
orientation or

alignment. As one can see from Eqs., the contribution to the width of the
magnetic

resonance line for aligned helium atoms should be diŽerent from that of oriented
atoms.

This diŽerence makes it possible to determine the rate constants of the two
simultaneously

occurring processes. In this work the experiment on optical orientation of atoms
has been

done for He* -Rb system. It was established that the rate constant for spin
exchange

(Cse) in collision of metastable 23S1 helium atom with a rubidium atom in 62S1=2
ground

state equals (1:8 § 0:8)10¡9cm3s¡1. The rate constant for chemiionization of
rubidium

atoms by metastable helium atoms (Cci) was determined at the same time to be
(3:1 §

0:6)10¡9cm3s¡1.

References

[1] S.P.Dmitriev, N.A.Dovator, and V.A.Kartoshkin, JETP Lett., 66, 151-154
(1997)

CP 46

68

Spin exchange and redistribution of the

spin-polarization at the interaction between ground

state alkali atoms and nitrogen atoms in gas

discharge

V.A.Kartoshkin

A.F.IoŽe Physico-Technical Institute, Russian Academy of Sciences,

Polytechnical str.26, 194021 St.-Petersburg, Russia.

E-mail: victor.kart@mail.ioŽe.ru.

In gas discharge an eŽective spin-exchange process is proceeding between
spin-polarized

ground state alkali atoms and ground state's nitrogen atoms, that demonstrates a
con-

servation of total electron spin and, consequently, a transfer of angular
momentum from

an ensemble of the previously spin-polarized alkali atoms to the electronic part
of the N

atoms in 4S3=2 state [1].

Consider the behavior of a quasi-molecular system consists of the nitrogen atom
with

electron spin angular momentum SA = 3/2, and alkali atom with electron spin
angular

momentum SB = 1/2. If the spins of the two interacting particles be SA and SB,
there

are two molecular states Vi, which correspond to diŽerent values of the total
spin (S)

of the quasi-molecule. In our case there are two molecular terms Vq(S = 2) and
Vt(S

= 1). Therefore the spin-exchange process can be described by two cross sections
¾1

and ¾2 corresponding to the change in the magnetic quantum numbers of the
interacting

particles, respectively, 3/2,1/2 *) 3/2,-1/2; -3/2,1/2 *) -1/2,-1/2;3/2,-1/2 *)
1/2,1/2; -

1/2,-1/2 *) -3/2,1/2 and -1/2,-1/2 *) 1/2,-1/2; 1/2,-1/2 *)-1/2,1/2. It can be
shown that

the cross sections are determined as

¾1=3/4jfq ¡ ftj2

and

¾2=1/4jfq ¡ ftj2,

where fq and fq are the scattering amplitudes on the quintet Vtq and triplet Vt
terms.

At the recombination of the spin-polarized N atoms the polarization can be
transmitted

to the N2 molecules. The mechanism of the N atoms recombination involves
nitrogen

atom recombination into the N2(A5P

) state. At the conservation of angular momentum

during the interaction the transfer of angular momentum from atoms to molecules
takes

place being to the spin-polarization of the N2 molecule. The redistribution of
angular

momentum between electron spin system and rotational system in the N2 molecule
results

in rotational polarization of the molecule too.

In this work the kinetics of optical orientation and spin-exchange collisions
between alkali

and nitrogen atoms have been investigated and equations, describing the
evolutions of

the polarized moments have been received. The equations describing the
redistribution

of the polarization in the N2 have been received too.

References

[1] S.P.Dmitriev, N.A.Dovator, and V.A.Kartoshkin, Optika i spektr.(in Russian)
104,

752-755 (2008)

CP 47

69

Large angle e-He scattering coincidence

experiment with magnetic angle changer

L. K losowski, M. Piwi´nski, D. Dziczek, K. Pleskacz and S. Chwirot

Institute of Physics, Nicolaus Copernicus University

Grudzi ¸ adzka 5/7, 87-100 Toru´n, Poland

E-mail: lklos@fizyka.umk.pl

Electron impact excitation of 21P1 state of He has been the first collisional
process investigated

using electronphoton coincidence technique. Since then, similar studies
approaching

the limit of quantum mechanically complete experiments have been carried out for

other collisional systems and stimulated a progress in both theoretical and
experimental

studies of electronic collisions. At the same time all that work has suffered
from lack

of experimental data on scattering parameters at large scattering angles. Such
measurements

could not be carried out for seemingly simple reason finite dimensions of
electron

beam sources and energy analysers.

We have shown recently [1] that such measurements could be performed if
trajectories

of electrons were suitably modified by a so-called magnetic angle changer (MAC)
[2, 3],

successfully used by other groups in measurements of differential cross-sections
[4].

We are presenting new experimental data for electron impact excitation of 21P1
state

of He atoms by 100 eV electrons. The measurements were carried out using angular

correlations technique with application of MAC and yielded first experimental
data on

scattering parameters for large scattering angles up to 180 .

Ab initio predictions are fairly consistent for low scattering angles where they
are also in

good agreement with available experimental data while serious discrepancies
exist at large

scattering angles [5, 6], where a lack of experimental data made it difficult to
improve the

consistency of various theoretical models.

References

[1] L. K losowski, M. Piwi´nski, D. Dziczek, K. Wi´sniewska, S. Chwirot, Meas.
Sci. Technol.

18, 3801 (2007)

[2] M. Zubek, N. Gulley, G. C. King, F. H. Read, J. Phys. B: At. Mol. Opt. Phys.
29,

L239 (1996)

[3] F. Read, J. Channing, Rev. Sci. Instrum. 67, 2372 (1996)

[4] B. Mielewska, Rad. Phys. Chem. 76, 418 (2007)

[5] N. Andersen, J. W. Gallagher, I. V. Hertel, Phys. Rep. 165, 1 (1988)

[6] D. V. Fursa, I. Bray, Phys. Rev. A, 52, 1279 (1995)

CP 48

70

Di usion coe cient and viriel coe cient of Krypton

Atoms in a Argon Gas at Low and Moderate

Temperature

C. Benseddik M.T. Bouazza and M. Bouledroua

1Physics Department and LAMA, Badji Mokhtar University, Annaba, Algeria

2Facult e de M edecine and LPR, Badji Mokhtar University, Annaba, Algeria

In the present work, using the Chapman-Enskog method for dilute gases, we have
cal-

culated the di usion coefcients of ground krypton atoms in a very weakly ionized
bu er

gas of argon. The calculations are carried out quantum mechanically. To do so,
we

have constructed the potential energy curve, relative to the 1 + molecular
state, through

which a Kr approaches Ar. The data points upon which the construction is made
are

smoothly connected to the long- and short-range forms. They are supposed to
behave

analytically like 1=Rn and exp( R), respectively. The spectroscopic data, Re =
7:42a0

and De = 510:084 Eh; are in accordance with what is available in literature. The
isotopic

e ect has also been examined. The classical second virial coefcients are also
calculated for

several temperatures. Our computation yields a value of the Boyle temperature of
about

TB 545:223K. Generally, the results of the transport parameters with temperature

show an excellent agreement with the available experimental data; the
discrepancies do

not exceed 5%.

CP 49

71

A theoretical report on ultracold collisions of two

monatomic cesium

M.T. Bouazza1 and M. Bouledroua2

1Physics Department, Badji Mokhtar University, Annaba, Algeria

2Facult e de M edecine and LPR, Badji Mokhtar University, Annaba, Algeria

In this work, we are interested in the elastic collisions of two 133Cs monatoms
at very

low temperatures. The behavior of such cold atoms is characterized by two
physical pa-

rameters: the scattering length andtheeffectiverangere. The study begins by the
con-

struction of the potential-energy curves of the two possible molecular
symmetries, namely,

X1 +

g and a1 +

u , through which two ground 133Cs(6s) interact. The exchange potential

of the form AR exp( R) is also taken into account. These constructed
interatomic

potentials are further introduced into the radial-wave equation to determine
numerically

the elastic phase shifts needed in the calculations of the total and partial
cross sections.

The scattering length and the eective range are therefore computed by using
quantum-

mechanical and semiclassical approaches.

CP 50

72

Tomography of laser cooled atoms in MOT using

Rydberg state excitation

V.M.Entin , I.I.Beterov, I.I.Ryabtsev, D.B.Tretyakov

Institute of Semiconductor Physics, Pr. Lavrentyeva 13, 630090, Novosibirsk,
Russia

E-mail: ventin@isp.nsc.ru

The position selective dimensional study of laser cooled atoms in magnetooptical
trap

(MOT) usually performed using optical detection. Nevertheless many years ago was

developed more precise method of imaging of atomic beams using ionization of
atoms and

detection of produced electrons and ions using secondary electron
multipliers[1]. This

technique demonstrates possibility to detect of a few atoms that making it
attractive

for experiments with small density of atoms[2]. In the current paper we have
performed

experiment directed to observe di erence in the space distribution of Rb atoms
in MOT

in the rst exited state (5P) caused various selection (dark or bright) of the
repumping

transition.

In the our experiment we produced cold atomic cloud of 107 Rb atoms cooled using

conventional MOT setup. After that atoms were optically exited to the Rydberg
state

using cascade transitions: 5S!5P!8S (decay)! 6P!nS;nD (n 37). First excitation

pulse (5P!8S) was performed by pulsed dye laser (Rodamine G6, 615 nm). Second,

pulse of the Ti:Sa laser at 740 nm was applied to the transitions 6P! nS;nD.
Laser

beams were focused to the trap and crossed under angle near 90 degree. The
Rydberg

atoms were detected using selective eld ionization technique. The Ti:Sa laser
beam

was 1D scanned across atomic cloud using de ector based on galvanometer driven
lens.

The optical de ection unit was controlled using computer. It allows us to make
position

sensitive measurement of the Rydberg state excitation rate.

Averaged data on counts of Rydberg atoms was used to determine population of the
5P

state in separate parts of the atomic cloud. Experimental tomography data
obtained for

locking of the repumping laser to the bright or dark transition, show di erent
5P 1D

pro les of the trap. Observed phenomena was in agreement with theoretical
predictions

and our previous results[3].

This technique is non-destructive method of measurement of exited state
distribution in

MOT. It could be used also for space selective reading(or writing) of quantum
states for

quantum computing experiments in optical lattices.

This work was supported by the Russian Academy of Sciences.

References

[1] N. F. Ramsey, "Molecular Beams", Clarendon Press, Oxford, (1956).

[2] I. I. Ryabtsev, D. B. Tretyakov, I. I. Beterov, and V. M. Entin, Phys. Rev.
A, 2007,

v.76, p.012722.

[3] V. M. Entin, I. I. Ryabtsev, JETP Letters, 2004, v.80, pp.161-166.

CP 51

73

Spatial light modulators for cold atom manipulation

Michael Mestre, Fabienne Diry, Bruno Viaris de Lesegno and Laurence Pruvost

Laboratoire Aimé Cotton, CNRS II, bat 505, campus dOrsay

91405 Orsay, France

E-mail: laurence.pruvost@lac.u-psud.fr

Spatial Light Modulators (SLMs) are programmable optical elements that can act
as

dynamical phase holograms on laser beams. Thus, a laser beam can be shaped into
a

pattern which is the Fourier transform of the hologram. It provides a flexible
method to

create dipole potentials in order to manipulate small objects. In this context,
our group

is investigating experiments using SLMs for cold atom cloud manipulation.

First we have focused on response time and diffraction pattern quality issues.
We have

demonstrated a device involving a SLM and an acousto-optic modulator (AOM/SLM)

with a refresh time of some micro-seconds and without bleed effect during the
hologram

changes [1]. This device would be well-suited for cold atom manipulation with

time-dependent dipole potentials. We have also studied different algorithms to
calculate

holograms.

Then, we have experimented the method on cold rubidium atoms, by applying a blue

detuned laser shaped into a hollow Laguerre-Gaussian beam. Such a profile is
obtained

by applying a helical-phase hologram to the laser beam. The cold atoms have been
guided

during their fall due to gravity, into the dark region of the Laguerre-Gaussian
mode. Being

far-detuned from resonance and dark where the atoms spend most of their time,
the light

field causes little scattering-induced losses and guiding is efficient. The
efficiency is studied

versus the detuning and the order of the Laguerre-Gaussian beam and is compared
to a

model for the atom capture into the two-dimensional potential.

Future applications of this technique will be presented and discussed in the
context of

cold atoms or Bose-Einstein condensates experiments.

References

[1] Fast reconfigurable and transient-less holographic beam-shaping realized by
a AOMSLM

device, M. Mestre, B. Viaris de Lesegno, R. Farcy, L. Pruvost, J. Bourderionnet,
A.

Delboulbé, B. Loiseaux, and, D. Dolfi ; Eur. Phys. J. Appl. Phys. 40, 269274
(2007).

CP 52

74

All-optical Bose-Einstein Condensation of Chromium

atoms and rf spectroscopy of cold Cr2 molecules

Q. Beaufils1, R. Chicireanu1, T. Zanon1, A. Crubellier2, B. Laburthe-Tolra1, E.

Mar´echal1, L. Vernac1, J.-C. Keller1 and O. Gorceix 1

1Laboratoire de Physique des Lasers, Universit´e Paris-Nord, 99 avenue
Jean-Baptiste

Cl´ement, 93430-Villetaneuse, France

2Laboratoire Aim´e Cotton, Bat 505, Campus dOrsay, 91405 Orsay, France

E-mail: olivier.gorceix@univ-paris13.fr

The study of quantum gases made of chromium atoms is compelling for several
reasons.

Being accessible to laser manipulation, chromium has a most abundant bosonic
isotope

52Cr and a 9-percent abundant fermionic isotope 53Cr. Most importantly, Cr atoms
carry

an exceptionally large magnetic moment of 6 μB. Consequently, Cr provides a
valuable

tool to study the physics of dipolar quantum gases as demonstrated in [1].

We present our recent achievement of a chromium Bose-Einstein Condensation
(Cr-BEC)

[2] using an all-optical procedure along with two innovative techniques:

- continuous accumulation of metastable 52Cr atoms in a mixed optical and
magnetic trap

[3];

- fast and intense rf sweeps to average to zero the magnetic potential and
optimize the

transfer efficiency from the Cr-MOT to the optical trap [4].

We also report on the rf spectroscopy and association of weakly bound Cr2
molecules

in the decatriplet 13 +

g state. These latter experiments are performed in the vicinity

of a d-wave Feshbach resonance at low magnetic field. Though the association
rate is

at present fairly low, we can study the spectroscopic properties of these cold
trapped

high-spin chromium molecules.

This work is supported by Conseil R´egional Ile-de-France, MENESR, CNRS, ANR, EU

and IFRAF.

References

[1] T. Lahaye et al. Nature, 448, 672 (2007)

[2] Q. Beaufils et al., arXiv :0712.3521

[3] R. Chicireanu et al., Eur. Phys. J. D, 45, 189 (2007)

[4] Q. Beaufils et al., arXiv :0711.0663

CP 53

75

Entangled photons from excitonic decay

in arti cial atoms

Marek Seliger, Ulrich Hohenester, and Gernot Pfanner

Institute for Physics, Karl-Franzens-University Graz, 8010 Graz, Austria

Email: marek.seliger@uni-graz.at

We theoretically investigate the production of polarization-entangled photons
through the

biexciton cascade decay in a single semiconductor quantum dot. Entangled photons
play a

key role in quantum communication and computation schemes. Furthermore,
generation

of single or entangled photons on demand has widespread applications in
experiments on

a single photon level. Semiconductor quantum dots are very attractive for these
devices

due to the strong con nement of charge carriers and the resulting atomlike
properties.

A biexciton decays radiatively through two intermediate exciton states. If these
are

degenerate, the two decay paths di er in polarization but are indistinguishable
otherwise

leading to polarization-entangled photons [1]. This ideal performance is usually
spoiled

by the electron-hole exchange interaction splitting the intermediate exciton
states by a

small amount and attaching a which-path information to the photon frequencies.

We discuss strategies to accomplish a high degree of entanglement, despite the
exciton

nestructure splitting: energetical alignment of the two exciton states [2] or
post-selection

of photons [3; 4]. We show how passive optical elements (spectral ltering and
time shifts)

at a single photon level a ect the quantum information encoded in the photon
wavepacket.

Here the solid state environment plays a crucial role in the e ective
measurement of the

intermediate exciton states [5]. Our results suggest that protocols for
solid-state based

quantum cryptography are more strict than previously thought.

References

[1] O. Benson, et al., Phys. Rev. Lett. 84, 2513 (2000).

[2] R.M. Stevenson, et al., Nature (London) 439, 179 (2006).

[3] N. Akopian, et al., Phys. Rev. Lett. 96, 130501 (2006).

[4] J.E. Avron, et al., Phys. Rev. Lett. 100, 120501 (2008).

[5] U. Hohenester, G. Pfanner, and M. Seliger, Phys. Rev. Lett. 99, 47402
(2007).

CP 54

76

Optimizing number sqeezing when splitting a

mesoscopic condensate

J. Grond1, U. Hohenester1 and J. Schmiedmayer2

1 Institut fur Physik, Karl-Franzens-Universitat Graz,

Universitatsplatz 5, 8010 Graz, Austria,

2 Atominstitut der osterreischischen Universitaten, Technische Universitat
Wien,

Stadionallee 2, 1020 Wien, Austria

E-mail: julian.grond@uni-graz.at

An atom interferometer can be built using Bose Einstein condensates, con ned in
magnetic

traps, which are split by continously transforming the trapping potential [1].
In order to

minimize phase di usion, due to the nonlinearity originating from atom-atom
interactions

in the condensate, number squeezing of the atoms in the wells is required.
Squeezing

occurs when tunneling becomes small due to the nonlinear interaction which
favors a

sharp number distribution in each well.

In adiabatic scenarios, squeezing is severely limited by the timescales of the
tunneling

dynamics, and therefore non-adiabatic strategies are favorable. In this
contribution we

show that optimal control theory (OCT) [2] allows to devise control strategies
which

signi cantly outperform adiabatic schemes. We rst discuss number squeezing in
the

framework of a generic two-mode model, and give an intuitive physical
explanation for

the OCT control strategy. For realistic magnetic microtraps, it becomes
important to

include a non-adiabatic wave function evolution beyond the generic two-mode
model. In

this work we describe the dynamical evolution of the two orbitals occupied by
the atoms

within the MCTDHB equations [3], which are based on a variational principle.

Our results cover several squeezing time scales as well as di erent numbers of
atoms in

the condensate. We compare adiabatic to non-adiabatic splitting with simple
control and

optimal control. By using OCT, we can handle non-adiabatic wave function
evolution,

and obtain number squeezed states on much shorter time scales in comparison to
other

strategies.

[1] T. Schumm, S. Ho erberth, L. M. Andersson, S. Wildermuth, S. Groth, I.
Bar-Joseph,

J. Schmiedmayer, and P. Kruger, Nat. Phys. 1, 57 (2005);

G.-B. Jo, Y. Shin, S. Will, T.A. Pasquini, M. Saba, W. Ketterle, D. E.
Pritchard, M.

Vengalattore, and M. Prentiss, Phys. Rev. Lett 98, 030407 (2007);

A. D. Cronin, J. Schmiedmayer and D. E. Pritchard, quant-ph/arXiv:0712.3703 .

[2] U. Hohenester, P. K. Rekdal, A. Borz, and J. Schmiedmayer, Phys. Rev. A 75,
023602

(2007).

[3] O. E. Alon, A. I. Streltsov and L. S. Cederbaum, Phys. Rev. A 77, 033613
(2008).

CP 55

77

Breakdown of integrability in a

quasi-one-dimensional ultracold bosonic gas

I.E. Mazets1,2, T. Schumm1 and J. Schmiedmayer1

1Atominstitut der ¨ Osterreichischen Universit¨aten, TU Wien, A1020 Vienna,
Austria

2A.F. Ioffe Physico-Technical Institute, 194021 St. Petersburg, Russia

We argue that virtual excitations of higher radial modes result in effective
three-body

collisions that violate integrability in a quasi 1 dimensional atomic Bose gas
in a tightly

confining waveguide and give rise to thermalization [1]. After adiabatic
elimination of

virtually excited radial modes, we obtain the Hamiltonian

ˆH

3b = −8 log

4

3

¯h!r 2

s

Z

dz ˆ ˆ ˆ ˆ ˆ ˆ

of this effective three-body elastic process. Here !r is the fundamental
frequency of the

radial confinement, s is the 3D s-wave scattering length. The corresponding
collision

rate per atom in a non-degenerate gas is

3b = C3b!r 2, = n1D 2

s

q

m!r/¯h,

where C3b 5.57, m is the atomic mass, n1D is the 1D atomic number density. We

demonstrate that, for typical experimental conditions [2] ( 0.007), the
three-body processes

dominate over thermalization via real radial mode excitation in the most
energetic

pairwise collisions for temperatures kBT < 0.4 ¯h!r. We compare our theoretical
findings

to the experimental results [3] and stress the further inhibition of
thermalization in a one

dimensional gas by correlations (atomic anti-bunching due to strong repulsion).

To summarize, a radially confined atomic gas is never perfectly 1D, and radial
motion

can be excited, either in reality or virtually even if both its temperature and
chemical

potential are below ¯h!r. Such quasi-1D systems exhibit more rich physics than
predicted

by the Lieb-Liniger model [4].

References

[1] I. Mazets, T. Schumm and J. Schmiedmayer, arXiv:0802.1701 (2008)

[2] S. Hofferberth et al., Nature 449, 324 (2007);

S. Hofferberth, et al., Nature Physics (in print), arXiv: cond-mat/0710.1575.

[3] T. Kinoshita, T. Wenger, and D.S. Weiss, Nature 440, 900 (2006).

[4] E.H. Lieb and W. Liniger, Phys. Rev. 130, 1605 (1963);

E.H. Lieb, Phys. Rev. 130, 1616 (1963).

CP 56

78

Light-shift tomography in an optical-dipole trap

J-F. Cl ement, J-P. Brantut, M. Robert de St Vincent, G. Varoquaux, R.A. Nyman,
A.

Aspect, T. Bourdel and P. Bouyer

Laboratoire Charles Fabry de l'Institut d'Optique, Campus Polytechnique, RD 128,

91127 Palaiseau France

We report on light-shift tomography of a cloud of 87Rb in a far-detuned
optical-dipole

trap. At this wavelength, the excited state of the cooling transition of 87Rb is
strongly

red-shifted, which enables us to perform energy-resolved imaging. We take
advantage of

this speci c feature by using it in two di erent situations.

(i) Mapping of the optical potential. Starting with a cold cloud with a smooth
density

pro le, we switch on a trapping laser at 1565 nm, and immediately take an
absorption

image of the atoms in the presence of the trap. By scanning the probe laser
frequency,

we perform a mapping of the equal light-shift regions.

(ii) Measurement of the atomic potential energy distribution. By counting the
total num-

ber of atoms detected at a given probe detuning, we directly measure the number
of atoms

having a given potential energy in the trap. We follow the evolution of this
atomic distri-

bution for a trapped cloud during the free-evaporation process, starting from a
strongly

out-of-equilibrium situation and relaxing towards a thermal distribution.

Using a spatially-varying light eld, this technique could be used to adress
atoms situated

in regions which size is smaller than the laser wavelength.

CP 57

79

Matter wave interferometry with K2 molecules

S. Liu1, I. Sherstov2, H. Kn¨ockel1, Chr. Lisdat2, E. Tiemann1

1Institut f¨ur Quantenoptik, Leibniz Universit¨at Hannover, D-30167 Hannover,
Germany

2Physikalisch-Technische Bundesanstalt, Bundesallee 100, D-38116 Braunschweig

We operate a matter wave interferometer on a beam of K2 molecules in a
Ramsey-Bord´e

configuration [1]. The two exits of this interferometer, with molecules in
either the excited

state or the ground state, allow distinct detection schemes for the matter wave

interference. While observation of the fluorescence of excited state molecules
shows the

matter wave interferences superimposed on a complicated incoherent background
due to

the molecular hyperfine structure, detection of ground state molecules behind
the interferometer,

exciting them with a fixed frequency laser, gives the interference pattern

on a simple symmetric background due to a single hyperfine component. Under
certain

geometric conditions any of the observed matter wave interferences is composed
of two distinct

structures, a Ramsey-Bord´e interference structure from four laser beams
employed

as beam splitters for the matter wave, and an additional Ramsey interference
structure

formed by only two laser beams acting as beam splitters.

The higher stability of the Ramsey-Bord´e setup due to cancellation of phase
drifts and

fluctuations in corresponding laser beams promises the Ramsey-Bord´e
interferometer as

a sensitive detector for collisions between molecules and ground state K atoms
in the

particle beam, when the collisions modify the phase and the damping of the
interference

pattern. The detection was done by deflecting atoms out of the molecular beam by
a

resonant laser field, thus switching the experiment between atom-molecule
collisions and

no collisions.

For a better understanding of the Ramsey interferences, we detected the ground
state

exit in two different distances near the beam splitters and further away
downstream of

the molecular beam. With active stabilization of the relative phases of the
laser beams

used as beam splitters the Ramsey interference shows a good phase stability. The
better

contrast of the Ramsey matter wave interferences as compared to the
Ramsey-Bord´e setup

recommends this method as well suited for further experimental applications.

We will introduce between the beam splitters a laser field near resonant to a
molecular

transition from either the excited state or the ground state to another state.
Such experiment

allows to determine the transition matrix element of the corresponding molecular

transition. By changing the collision characteristics of the K atoms by exciting
them to

Rydberg states, the collisions between potassium atoms and molecules will be
investigated.

The present status of the matter wave experiment will be presented.

References

[1] Chr. Lisdat, M. Frank, H. Kn¨ockel, M.-L. Almazor, E. Tiemann, Eur. Phys. J.
D 12,

235-240 (2000)

CP 58

80

A magnetic lens for cold atoms tuned by a rf ¯eld

E. Marśechal, B. Laburthe-Tolra, L. Vernac, J.-C. Keller, and O. Gorceix

Laboratoire de Physique des Lasers, UMR 7538 CNRS, Universitśe Paris Nord, 99

Avenue J.-B. Clśement, 93430 Villetaneuse, France

Email : marechal@galilee.univ-paris13.fr

The combination of static inhomogeneous magnetic ¯elds with a strong resonant rf
¯eld

has been recently used in many groups to realize new trapping geometries, like
double well

potentials, or bubble-like traps [1; 2]. A rf ¯eld allows indeed to distort
static magnetic

potentials into new 'adiabatic potentials' that can be continuously tailored and
tuned by

changing the rf ¯eld parameters [3]. Another possibility is to use rf ¯elds to
change the

properties of atom-optics elements like magnetic lenses or magnetic mirrors.
Following

this idea, we have experimentally investigated how the focal length of a
magnetic lens can

be tuned with rf.

The experiment is performed using a spin polarized cloud of cold cesium atoms.
The rf

dressed lens is realized with two components : a static magnetic lens, made of a
simple

coil, and a rf ¯eld. The inhomogeneous static ¯eld de¯nes a surface where atoms
are

resonant with the rf ¯eld. As atoms cross this surface, their spin is reversed,
and the

eŽect of the lens (initially converging or diverging, depending on the initial
polarization)

is reversed. The magnetic lens is separated by the rf interaction surface into
two parts,

and become equivalent to a doublet. The position of the interaction region, and
therefore

the focal length of the doublet can be tuned by changing the rf frequency.

After a 72 cm free fall, atoms cross the lens center, and are focused typically
10 cm

below, in a 500 ¹m 1=e2 diameter spot. We show that by changing the rf frequency

between 100 MHz and 250 MHz, the 10 cm magnetic focal length can be tuned over

§2 cm. Depending on the rf antenna position, the magnetic lens can be made more

converging than without rf, and can be changed by increasing the rf frequency
from a

converging lens to a converging mirror. The magnetic lens, in combination with a
strong

rf ¯eld, is conveniently described in the dressed-atom picture. The probability
that atoms

follow the adiabatic rf-dressed potentials can be evaluated by a Landau-Zener
model, that

determines the rf power requirements to get a lens with good performances. Under
our

experimental conditions, 10 W of rf is necessary.

Our experimental investigation of the rf-dressed lens, supported by numerical
simulations

is presented in [4]. This rf-dressing procedure can be combined with the
well-developed

integrated atom chip technology, to add coherent control to magnetic atom chips.

We acknowledge ¯nancial support by IFRAF (MOCA project).

References

[1] Y. Colombe, E. Knyazchyan, O. Morizot, B. Mercier, V. Lorent, H. Perrin,
Europhys.

Lett. 67, 593 (2004)

[2] I. Lesanovsky, T. Schumm, S. HoŽerberth, L. M. Andersson, P. KrÄuger, J.
Schmied-

mayer, Phys. Rev. A 73, 033619 (2006)

[3] O. Zobay, B. M. Garraway, Phys. Rev. Lett. 86, 1195 (2001)

[4] E. Marśechal, B. Laburthe-Tolra, L. Vernac, J.-C. Keller, O. Gorceix, Appl.
Phys. B,

91, 233 (2008)

CP 59

81

Stability and d -wave collapse of a dipolar

Bose-Einstein condensate

T. Pfau , Th. Lahaye, J. Metz, B. Fr¨ohlich, T. Koch, A. Griesmaier

5. Physikalisches Institut, Universit¨at Stuttgart, Pfaffenwaldring 57, D-70550
Stuttgart,

Germany

t.pfau@physik.uni-stuttgart.de

Although the phenomenon of BoseEinstein condensation is a purely statistical
effect that

also appears in an ideal gas, the physics of BoseEinstein condensates (BECs) of
dilute

gases is considerably enriched by the presence of interactions among the atoms.
In usual

experiments with BECs, the only relevant interaction is the isotropic and
short-range

contact interaction, which is described by a single parameter, the scattering
length a. In

contrast, the dipoledipole interaction between particles possessing an electric
or magnetic

dipole moment is of long range character and anisotropic, which gives rise to
new

phenomena [1]. Most prominently, the stability of a dipolar BEC depends not only
on

the value of the scattering length a, but also strongly on the geometry of the
external

trapping potential. Here, we report on the experimental investigation of the
stability of a

dipolar BEC of 52Cr as a function of the scattering length and the trap aspect
ratio. We

find good agreement with a universal stability threshold arising from a simple
theoretical

model. Using a pancake-shaped trap with the dipoles oriented along the short
axis of

the trap, we are able to tune the scattering length to zero, stabilizing a
purely dipolar

quantum gas [2].

We also experimentally investigate the collapse dynamics of a dipolar condensate
of 52Cr

atoms when the s-wave scattering length characterizing the contact interaction
is reduced

below a critical value. A complex dynamics, involving an anisotropic, d-wave
symmetric

explosion of the condensate, is observed on time scales significantly shorter
than the trap

period. At the same time, the condensate atom number decreases abruptly during
the

collapse. We compare our experimental results with numerical simulations of the
threedimensional

Gross-Pitaevskii equation, including the contact and dipolar interactions as

well as three-body losses. The simulations indicate that the collapse is
accompanied by

the formation of two vortex rings with opposite circulations.

References

[1] Th. Lahaye, T. Koch, B. Fr¨ohlich, M. Fattori, J. Metz, A. Griesmaier, S.
Giovanazzi,

T. Pfau Strong dipolar effects in a quantum ferrofluid Nature 448, 672 (2007).

[2] T. Koch, Th. Lahaye, J. Metz, B. Fr¨ohlich, A. Griesmaier, T. Pfau
Stabilizing a

purely dipolar quantum gas against collapse, Nature Physics 4, 218 (2008).

CP 60

82

Blue cooling transitions of thulium atom

K. Chebakov, N. Kolachevsky, A. Akimov, I. Tolstikhina, P. Rodionov, S.
Kanorsky, and

V. Sorokin

P.N. Lebedev Physics Institute, Leninsky prosp. 53, Moscow, 119991 Russia

It has been shown recently that Yb [1] and Er [2] atoms from the lanthanides
group can

be eąciently laser-cooled using strong transitions near 400 nm. Degenerate Fermi
gases

of ytterbium have been also recently demonstrated using laser-cooling based
technic [3].

Our goal was to investigate the possibility of laser cooling of Tm atom. Among
other

lanthanides, thulium possesses relatively simple level structure.Moreover, it
has only one

stable isotope 169Tm with a nuclear spin of I = 1/2 which makes possible to use
schemes

for sub-Doppler cooling. Laser-cooled thulium is a favorable candidate for
optical clocks

applications, since the forbidden transition between the ¯ne structure sublevels
(Jg =

5=2) ¡ (J0

g = 7=2) of the ground state 4f136s2 (¸ = 1:14 micron) has a spectral width

of approximately 1 Hz. The collisional shift of such kind of transitions in
lanthanides is

suppressed because of the outer closed 6s2 shell [4], which allows for precision
spectroscopy

in a dense atomic cloud.

We studied two candidates for cooling transitions from the ground state 4f136s2
(Jg = 7=2)

to the states 4f12(3H5)5d3=26s2 (Je = 9=2) at 410.6 nm and 4f12(3F4)5d5=26s2 (Je
= 9=2)

at 420.4 nm. By means of saturation absorption spectroscopy, we measured the
hyper¯ne

structure and rates of these transitions. We evaluated the life times of
appropriate excited

levels as 15.9(8) ns and 48(6) ns, respectively. Decay rates from these levels
to neighboring

opposite-parity levels were evaluated by means of Hartree-Fock calculations [5].
The

fraction of atoms which do not return to the ground state is about 10¡5 and 5 ¢
10¡4

for the 410.6 nm and 420.4 nm transitions respectively. We conclude that the
strong

transition at 410.6 nm with relative slow leakage rate can be used for the
eącient cooling

of Tm I.

We also measured hyper¯ne structure of two nearby transitions from the ground
state to

the states 4f13(2F7=2)6s6p(1P1) (Je = 5=2) at 409.4 nm and 4f12(3F4)5d5=26s2 (Je
= 7=2)

at 418.9 nm, which can be used for ¤-type excitation of ¸ = 1:14 ¹m transition.

References

[1] R. Maruyama et al., Phys. Rev. A 68, 011403(R), (2003).

[2] J.J. McClelland and J.L. Hansen, Phys. Rev. Lett. 96, 143005 (2006).

[3] Takeshi Fukuhara, Yosuke Takasu, Mitsutaka Kumakura, and Yoshiro Takahashi
Phys.

Rev. Lett. 98, 030401 (2007).

[4] C.I. Hancox, S.C. Doret, M.T. Hummon, L. Luo, J.M. Doyle, Nature, 431, 281
(2004).

[5] R.D. Cowan, The Theory of Atomic Structure and Spectra, Berkeley, CA:
University

of California Press, (1981).

CP 61

83

Free-fall expansion of nite-temperature

Bose-Einstein condensed gas in the non

Thomas-Fermi regime

J. Szczepkowski1;2, R. Abdoul1;5, R. Gartman1;5,

W. Gawlik1;4, M. Witkowski1;3, J. Zachorowski1;4, M. Zawada1;5

1National Laboratory for Atomic Molecular and Optical Physics

Grudzi adzka 5, 87-100 Toru n, Poland,

2Institute of Physics, Pomeranian University

76-200 S lupsk, Arciszewskiego 22B, Poland,

3Institute of Physics, University of Opole

Oleska 48, 45-052 Opole, Poland,

4Institute of Physics, Jagiellonian University

Reymonta 4, 30-057 Krak ow, Poland,

5Institute of Physics, Nicolaus Copernicus University

Grudzi adzka 5, 87-100 Toru n, Poland.

E-mail: jszczepkowski@wp.pl

Since 1995 we have opportunity to experimental study degenerate and
non-degenerate

trapped atomic gases at ultra low temperatures. At nite temperatures the free
expansion

of the dilute gas leads to spatially thermal distinct and condensed phases. The
thermal

phase is negligible at temperatures much smaller than the critical temperature
Tc, and

behavior of the condensed part is mainly determined by the interplay between the
trapping

potential and the atomic interactions. At the temperatures close to Tc there are
usually

more thermal dilute gases than the condensed one. In this case also interactions
between

two phases, thermal and condensed, have a ect on the behavior of the condensed
fraction.

The F. Gerbier et all[1] show in uence of this interaction to evolution of free
falling Bose-

Einstein condensate (BEC) in the presence of the thermal fraction for the
condensate

with assumption the Thomas-Fermi regime in the condensate phase.

In our experiment we analyze a free expansion of 87Rb BEC release from the
magnetic

trap[1] with presence of the thermal part dilute atomic gases using standard
time-of- ight

technique. As a result we note the dependence between condensed aspect-ratio
(ratio

of axial to radial radii) of the condensate as a function of amount of the
condensate

fraction in the dilute atomic gas, after 15 ms free expansion. We investigate
region where

the Thomas-Fermi regime is not hold in BEC. The aspect ratio dependence results
from

interplay between condensed and non-condensed fraction of the dilute gas and a
small

number of the atoms in the condensed fraction at the temperature close to Tc.

References

[1] F. Bylicki,W Gawlik, W. Jastrz ebski, A. Noga, J. Szczepkowski, M.
Witkowski,

J. Zachorowski, M. Zawada, Acta Phys. Polon. A 113, 691 (2008)

[2]F. Gerbier, J. H. Thywissen, S. Richard, M. Hugbart, P. Bouyer, and A.
Aspect, Phys.

Rev. A , 70, 013607 (2004)

CP 62

84

Resonance Interaction between Cold Rb Atoms and

a Frequency Comb

E. Tereschenko1;2, M. Egorov1;2, A. Sokolov1;2, A. Akimov1;2, V. Sorokin1;2,

N. Kolachevky1;2

1 P.N. Lebedev Physics Institute, Leninsky prosp. 53, 119991 Moscow, Russia

2 Moscow Institute of Physics and Technology, 141704 Dolgoprudny, Russia

A long life time of atoms in a magneto-optical trap (MOT) makes it a powerful
tool to

study interactions with optical ¯elds processing small cross sections (see e.g.
[1]). Since

the life time in MOT can reach a few seconds, even processes with characteristic
rates of

1 s¡1 can be easily analyzed if they result in losses of trapped atoms.

We have investigated the interaction of laser-cooled 87Rb atoms in a MOT with a
femtosec-

ond (fs) laser radiation in the spectral region 760-820 nm. We show that in a
wide range

of average intensities of the fs laser ¯eld (< 300W/cm2) the dominating process
is the cas-

cade ionization. In this case the femtosecond radiation interacts with the
atomic ensemble

both as spectrally-narrow components (a frequency comb) and as a powerful
ionizing laser

¯eld. Atoms excited by a single mode of a frequency comb from the 5P3=2(F = 3)
to the

5D5=2(F = 2; 3; 4) hyper¯ne sublevels are consequently ionized by a full power
of the fs

laser from the 5D level to the continuum. By tuning the repetition rate frep of
the fs

laser we observe the periodic spectrum in the MOT luminescence at 780nm (the
cooling

transition) reproducing the hyper¯ne structure of the 5D level (see Fig. 1a).

Figure 1: (a) | MOT luminescence signal vs. detuning of the fs laser repetition
rate ąfrep.

(b) | dependency of the MOT loading rate on the fs laser power.

We have quantitatively analyzed the ionization of the 5D5=2 level by monitoring
the load-

ing rate of the MOT at diŽerent powers of the fs laser radiation (Fig. 1b) using
an auxiliary

cw laser locked to the 5P3=2(F = 3) ! 5D5=2(F = 4) at 776 nm. A sensitive method
al-

lowing accurate determination of the 5/2 5D level population is developed [2].

[1] O. Marago, D. Ciampini, F. Fuso, E. Arimondo, C. Gabbanini, and S. T.
Manson,

Phys. Rev. A 57, R4110 (1998).

CP 63

85

Optical tailoring of spatial distribution of the BEC

and non-degenerate cold atoms.

Non-periodic optical lattice

M. Witkowski1,3, R. Gartman1,5, W. Gawlik1,4, J. Szczepkowski1,2, M. Zawada1,5

1National Laboratory for Atomic Molecular and Optical Physics

Grudziadzka 5, 87-100 Torun, Poland,

2Institute of Physics, Pomeranian University

76-200 Słupsk, Arciszewskiego 22B, Poland,

3Institute of Physics, University of Opole

Oleska 48, 45-052 Opole, Poland,

4Institute of Physics, Jagiellonian University

Reymonta 4, 30-057 Kraków, Poland,

5Institute of Physics, Nicolaus Copernicus University

Grudziadzka 5, 87-100 Torun, Poland.

E-mail: mwitkowski@uni.opole.pl

Optical lattices are the instruments of great importance in many fields of
atomic physics

like manipulating of neutral particles, quantum computing, etc. The common
method of

getting a periodic optical lattice is to use the interference of two or more
laser beams

which form an array of periodic light-shift potentials.

We demonstrate a new method of creating an optical lattice of either
non-degenerate

cold atoms or Bose-Einstein condensates. The lattice is obtained when the cloud
of cold

atoms is illuminated by a focused, off-resonant laser beam split into several
beams by

a diffraction process. The resulting lattice is non-periodic.

In our experiment we used 87Rb atoms trapped in the magnetic trap of the
Ioffe-Pritchard

type. This is an anisotropic and harmonic trap characterized by frequencies:
radial

!r = 2 ˇ 137 Hz and axial !a = 2 ˇ 12 Hz [1]. The laser beam of a frequency
close

to the D1 line of 87Rb was used in the experiment.

We analyze the evolution of that kind of lattice either in a magnetic trap or
during time of

flight after the atoms are released from the trap. Due to interactions between
atoms and

near resonant light the characteristic regular structure of atoms appears. We
characterize

the basic properties of this structure in two cases of a nondegenerate atom
cloud and

a BEC. In particular, we analyze the effect of the laser frequency on the
formation

process of optical lattice.

Our method can be another way of studying phenomena where an optical lattice is
a necessary

instrument. The presented method of creating the optical lattice might be an

alternative to the standard counter-propagating laser beams method.

References

[1] F. Bylicki, W. Gawlik, W. Jastrzebski, A. Noga, J. Szczepkowski, M.
Witkowski,

J. Zachorowski, M. Zawada, Acta Phys. Polon. A 113, 691 (2008).

CP 64

86

Laser techniques for atom-scale technologies

F. Tantussi, N. Por¯do, F. Prescimone, V. Mangasuli,

M. Allegrini, E. Arimondo and F. Fuso

CNISM and Dipartimento di Fisica Enrico Fermi, Universitľa di Pisa

Largo Bruno Pontecorvo 3, I-56127 Pisa, Italy

e-mail: fuso@df.unipi.it

Among the various applications envisioned for laser-cooling and manipulation of
neu-

tral atoms, those dealing with nanostructure fabrication appear particularly
challeng-

ing. Atomic NanoFabrication (ANF [1]) demonstrated production of regular
nanopat-

terns through the occurrence of dipolar forces and the consequent spatial
segregation of

an atom beam (optical mask). Recently, large technological interest is being
attributed

to develop methods for the controlled deposition of few, eventually single,
atoms onto

a surface. The realization of atom-scale technologies is one of the major
challenges in

realizing novel nanodevices from single atomic, or molecular, elements, with a
potentially

large impact in emerging areas such as nanophotonics, spintronics, quantum
computation

systems, advanced biomedical applications.

We have developed an experimental setup aimed at directly depositing few atoms
onto a

surface under laser-manipulation control. Core of the setup is a Cesium beam
produced

out of a modi¯ed magneto-optical trap (MOT) [2] which exhibits sub-thermal
kinetic

energy in the longitudinal direction and, after due collimation by 2D optical
molasses,

shows a residual divergence in the mrad range. The setup has been already
employed

in resist-assisted fabrication of regular arrays of nanotrenches (45 nm wide)
onto Gold

through interaction with a 1D optical mask [3]. We are presently exploring the
regime of

low °ux, low temperature direct deposition [4]. Thanks to an in-situ Scanning
Tunnelling

Microscope (STM), sample features can be investigated at the atomic scale. A
variety of

substrates has been used, ranging through Graphite to organic self-assembled
monolayers.

Deposition of stable isolated Cesium nanostructures consisting of a few atoms
has been

demonstrated, with metal-like electronic features. Due to the small longitudinal
velocity

of the atoms, relatively long interaction times with the optical mask can be
achieved,

leading to the occurrence of a pure channelling regime for the guided atom
trajectories.

In the low surface coverage regime, the interaction produces both a spatial
modulation

of the deposited atom density and a peculiar nanoisland morphology, which
acquires a

cigar-like shape oriented in agreement with the optical mask. Results suggest
however that

nanostructure features are ruled by a complicated interplay between
laser-manipulation

and local properties of the substrate, involving a variety of surface physics
eŽects to be

still completely unravelled.

Financial support by Fondazione Cassa di Risparmio di Pisa (PR/05/137) is
gratefully

acknowledged.

References

[1] For a review see, for instance, D. Meschede and H. Metcalf, J. Phys. D 36,
R17 (2003).

[2] A. Camposeo, et al., Opt. Commun. 200, 231 (2001).

[3] C. O'Dwyer, et al., Nanotechnology 16, 1536 (2005).

[4] F. Tantussi, et al., Mat. Sci. Eng. C 27, 1418 (2007).

CP 65

87

Emission from Silicon/Gold nanoparticle systems

M. Bassu1, F. Tantussi1, L. Strambini2, G. Barillaro2, M. Allegrini1, F. Fuso1

1 CNISM and Dipartimento di Fisica E. Fermi, Universitľa di Pisa, I-56127 Pisa,
Italy

2 Dipartimento di Ingegneria dell'Informazione, Universitľa di Pisa, I-56122
Pisa, Italy

e-mail: fuso@df.unipi.it

Investigation of systems comprising metal nanoparticles (NPs) with plasmonic
features

and light-emitting Silicon is stimulated by distinct motivations. First of all,
integration

of NPs with materials and technologies used in conventional optoelectronics
represents

an important step towards practical applications in the emerging areas of
plasmonics

and nanophotonics [1]; moreover, spectroscopy of such systems opens the way to
study

the interplay between distinct sub-systems with speci¯c optical properties. When
prop-

erly designed, such interplay can be used to tailor the system behavior, for
instance by

modifying the emission spectrum or the overall quantum eąciency.

We have analyzed photoluminescence (PL) of samples produced by a novel
anodization-

free electrochemical etching of Si catalyzed by Gold NPs. The process is based
on the

production of Au NPs through rapid thermal annealing of a thin Au ¯lm evaporated

onto a Si wafer. Etching in a H2O2:HF (10:1) solution then leads to mesopore
structures

diverging from Au NPs. Microscopy of the produced samples demonstrates the
achieve-

ment of a porous-Si network embedding NPs typically sized in the few tens of
nanometers

range. The technique, which can be considered as a variant of the HOME-HF
process

[2], exhibits technologically appealing features: for instance, no anodization
is required,

favoring integration with conventional Si technologies; by lithographical
de¯nition of the

pristine Au ¯lm, porization can be easily achieved in prede¯ned patterns, thus
leading to

nanostructured light-emitting samples.

Samples produced in various conditions, starting from either p- or n-doped Si,
have been

analyzed upon both cw and pulsed laser excitation in the violet/UV range, at
room and

low temperature. Results demonstrate eącient PL in the visible, peaked around
600-650

nm. Comparison with samples which underwent an Au-removal process based on
chemical

etching suggests that NPs play a prominent role in ruling the emission: after
Au-removal

the emission intensity gets remarkably smaller and is spectrally shifted. The
role of NPs

is well con¯rmed by simulations of the plasmon resonance for Au NPs in the
actual con-

ditions (size distribution and dielectric constant of the embedding medium)
experienced

in the samples, resulting peaked slightly above 600 nm. Analysis of the emission
lifetime

as a function of the temperature reveals a puzzling behavior which suggests an
intriguing

contribution of both radiative and non-radiative phenomena. Nanoscopic
investigations

have been started based on scanning near-¯eld optical microscopy (SNOM), a
technique

already proven successful with similar systems [3]. Results show distinctive
features for

the near-¯eld maps which describe scattering and emission, simultaneously
acquired with

our SNOM. Interpretation, still in progress, will shed light on the interaction
between

NPs and Si occurring in the near-¯eld.

References

[1] For a review see, for instance, S. Maier, et al., Nature Materials 2, 229
(2003).

[2] X. Li and P.W. Bohn, Appl. Phys. Lett. 77, 2572 (2000).

[3] F. Fuso, et al., J. Appl. Phys. 91, 5495 (2002).

CP 66

88

As3d core level studies of (GaMn)As annealed under

As capping

I.Ulfat1,2, J.Adell1,2, J.Sadowski2,3, L.Ilver1 and J.Kanski1

1Department of Applied Physics, Chalmers University of Technology, Goteborg,
Sweden

2MAX-Lab, Lund University, Lund, Sweden

3Institute of Physics, Polish Academy of Sciences, Warszawa, Poland

In recent years the DMS (GaMn)As has fascinated research community as a
promising

candidate for spintronic application. It is of exacting significance due to both
its compatibility

with existing III-V technology and great progress in improving its magnetic

properties. Being a supersaturated solid solution of Mn in GaAs matrix,
fabricated by

low temperature molecular beam epitaxy (LT-MBE) ,the material contains a high
density

of various defects compensating Mn acceptors. This results in the deterioration
of

its magnetic properties as the ferromagnetism in (GaMn)As occurs due to an
indirect

exchange between magnetic moments of Mn ions mediated by free holes .

The ferromagnetic state of (GaMn)As is known to be established by post growth
annealing.

Until recently such annealing has been carried out in air or nitrogen.However,
once

the sample has been exposed to air, its surface cannot be restored. This means
that

(GaMn)As annealed in this way are not useful for further epitaxial overgrowth to
be included

in multilayer structures. In order to meet this requirement an innovative
annealing

procedure was devised in which the reactive medium (oxygen or nitrogen) is
replaced by

a surface layer of amorphous As thus removing the interstitial Mn [1].

To observe the presence of reacted surface layer containing As, As3d core level
spectra

taken at BL41 at Swedish National Synchrotron Radiation Facility (MAX-lab) have
been

analyzed. In order to identify the contribution from the reacted layer, spectra
from pure

GaAs and (GaMn)As subjected to post growth annealing have been investigated. Our

data indicate that the interface between the out-diffusing Mn and the As capping
results

in a uniform epitaxial continued layer structure of MnAs. This is rather
unexpected as

zincblende MnAs is known to be unstable, and MBE growth of MnAs on GaAs normally

results in the formation of clusters with hexagonal structure.

[1] M.Adell et al., Appl.Phys.Lett.6, 112501 (2005)

CP 67

89

Pulsed laser Deposition Simulation for Graphite

Target using Mont-Carlo Method

N. Alinejad, M. Jahangiri, F. Izadi

Physics and Nuclear Fusion Research School, Tehran, Iran

Pulsed laser deposition method for producing thin lms is investigated. This
deposition

method include several stages such as absorption of the laser beam in the target
material,

evaporation of the material producing plume of atoms or molecules, strong
interaction

of the laser beam with the plumb to produce plasmas, and nally deposition of
atoms

or molecules on the substrate surface. The growth of the thin lm in the initial
stage

is simulated using Mont Carlo method. Our simulation indicated that by
decreasing the

duration of the pulse together with the decrease in laser energy, the thin lm
growth is

steady so that the uniform and homogenous layer is produced. Keywords: pulsed
laser

deposition, thin lms, simulation, Graphite PACS No: 310.0310, 140.0140

CP 68

90

Precision Measurement of the 3He-3H mass ratio

with the MPIK/UW-PTMS

Christoph Diehl1, David Pinegar1, Robert S. Van Dyck Jr.2 and Klaus Blaum1

1Max-Planck-Institut fur Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg,
Germany

2Department of Physics, University of Washington, Seattle, WA 98195-1560, USA

e-mail: christoph.diehl@mpi-hd.mpg.de

The precise determination of the 3He-3H mass ratio is of utmost importance for
the

measurement of the electron anti-neutrino mass performed by the Karlsruhe
Tritium

Neutrino experiment (KATRIN) [1]. By determining this ratio to an uncertainty of
1

part in 1011, systematic errors of the endpoint energy in the -decay of 3H to
3He can be

checked in the data analysis of KATRIN [2].

To reach this precision, a Penning Trap Mass Spectrometer (MPIK/UW-PTMS) was

constructed at the University of Washington [3], which is now transferred to the
Max-

Planck-Institute for Nuclear Physics in Heidelberg in the new division \Stored
and Cooled

Ions".

The Penning trap technique allows for the most precise mass measurements (<
1010

relative uncertainty for stable ions) by the determination of the
eigenfrequencies of a

single stored ion in a superposition of an electric and magnetic eld [4].

Special design features of the MPIK/UW-PTMS are the utilization of an external
ion

source and the double trap con guration. The external Penning ion source e
ciently ion-

izes the helium and tritium gas. Also, external ion creation can give superior
elimination

of unwanted ion species compared to the previously utilized internal eld
emission tips.

The design as a double Penning trap allows for several monitoring capabilities
(e.g. using

one trap as a voltage reference), as well as for a faster measurement procedure.
This

should help to avoid problems due to long-term drifts in the experimental
conditions.

The MPIK/UW-PTMS will be set into operation in Heidelberg by the end of 2008. We

will present the design of the setup as it was constructed and tested at the
University of

Washington.

References

[1] Ch. Weinheimer, Nucl. Phys. B 168, 5 (2007)

[2] E. W. Otten, J. Bonn, Ch. Weinheimer, Int. J. Mass Spec. 251, 173 (2006)

[3] D. B. Pinegar, S. L. Zafonte, R. S. Van Dyck Jr., Hyperf. Int. 174, 47
(2007)

[4] K. Blaum, Phys. Rep. 425, 1 (2006)

CP 69

91

CP 70

92

Isotope shift in the electron affinity of sulfur:

observation and theory

T. Carette1, C. Drag 2, C. Blondel2, C. Delsart2,

C. Froese Fischer3, M. Godefroid1 and O. Scharf1

1 Service de Chimie Quantique et Photophysique, Universit´e Libre de Bruxelles -

CP160/09, B 1050 Brussels, Belgium

2 Laboratoire Aim´e-Cotton, CNRS, Universit´e Paris-sud, F-91405 ORSAY cedex,
France

3 Department of Electrical Engineering and Computer Science, Box 1679B,
Vanderbilt

University, Nashville TN 37235, USA

Photodetachment microscopy [1] was performed on a beam of S− generated by a hot

cathode discharge in a mixture of 98% Ar and 2% CS2, with the sulfur isotopes in
natural

abundances. Isotope 34 was selected by a Wien velocity filter. Laser excitation
was

provided by a CW ring laser operating with the Rhodamine 590 dye. The laser
wavenumber

was measured by an Angstr¨om WS-U lambdameter, with an accuracy better

than 10−3 cm−1. Subtracting the photoelectron energy found by analysing the
electron

interferogram from the photon energy, one can determine the electron affinity
eA. The

result for eA(34S) is 16 752.978(10) cm−1, to be compared to the previously
measured

eA(32S)=16 752.976(4) cm−1 [2]. Technical correlations between the two
measurements

lets the isotope shift exp = eA(34S) − eA(32S) be a little more accurate than
the more

imprecise electron affinity. Numerically exp = +0.002(8) cm−1, in wich the (2 )
error

bars leave room for a normal or anomalous result.

Ab initio calculations of the isotope shift on the electron affinity from the
infinite-mass

systems S−/S were carried out, adopting the multiconfiguration Hartree-Fock
(MCHF)

approach using the ATSP2K package [3]. Our model includes in a systematic way
valence

correlation, limiting the core to the n=2 shell. The one-electron orbitals are
optimized

using a single- and double- multi-reference expansions. Configuration-iteraction
(CI) calculations

including up to 6ˇ105 configuration state functions were performed in order to

complete the convergence patterns of the S− energy, resulting in a
unextrapolated nonrelativistic

electron affinity of eA(1S) = 16 987(44)cm−1. The theoretical isotope shift

value theor = eA(34S) − eA(32S) = −0.0022(2)cm−1 is found to be rather small but

definitely negative. The analysis of the various contributions reveals a very
large specific

mass shift that counterbalances the normal mass shift, while the positive field
shift is

smaller than the total mass contribution by one order of magnitude.

[1] C. Blondel, C. Delsart, and F. Dulieu. Phys. Rev. Lett. 77 (1996) 3755.

[2] C. Blondel, W. Chaibi, C. Delsart, C. Drag, F. Goldfarb, and S. Kr¨oger.
Eur. Phys. J. D

33 (2005) 335 ; C. Blondel, W. Chaibi, C. Delsart, and C. Drag. J. Phys. B: At.
Mol.

Opt. Phys. 39 (2006) 1409;

[3] C. Froese Fischer, G. Tachiev, G. Gaigalas, and M. R. Godefroid. Comp. Phys.
Com.

176(2007)559

CP 71

93

Theoretical study of attosecond chronoscopy of

strong-¯eld atomic photoionization

A.K. Kazansky1;2 and N.M. Kabachnik3;4

1 Fock Institute of Physics, State University of Sankt Petersburg, Sankt
Petersburg

198504, Russia

2 Donostia International Physics Center, E-20018 San Sebastian/Donostia, Basque

Country, Spain

3 FakultÄat fÄur Physik, UniversitÄat Bielefeld, D-33615 Bielefeld, Germany

4 Institute of Nuclear Physics, Moscow State University, Moscow 119991, Russia

A model which describes the time evolution of strong-¯eld photoionization of
atoms is

presented. Based on the numerical solution of the non-stationary SchrÄodinger
equation,

the model allows one to predict and to interpret the results of experiments on
double

photoionization of atoms by a combined action of a very short (attosecond) XUV
pulse

and a few-cycle IR pulse of a powerful laser at various delay times between the
two

pulses. Depending on the binding energy of the ionized electron, two types of
process

are considered. If the electron is tightly bound (Ne case), the XUV pulse
ionizes the

atom and shakes up another (outer) electron to an excited state, which is
subsequently

ionized by the strong IR ¯eld. For an atom with a weakly bound outer electron
(Li case),

the IR ¯eld ionizes the latter, while the XUV pulse, ionizing the inner shell,
terminates

(or suppresses) the strong ¯eld ionization. In both cases the yield of doubly
ionized ions

strongly depends on the delay time between the two pulses, revealing "steps",
oscillations

and other features which characterize the time evolution of the ionization
process. The

presented model describes qualitatively the results of recent experiments on Ne
[1].

References

[1] M. Uiberacker et al., Nature 446, 627 (2007)

CP 72

94

Generation of ultra-short X-ray pulses in cluster

system during ionization by femto-second optical

pulse

A.V. Glushkov12, O.Yu. Khetselius2, A.V. Loboda2

1Institute for Spectroscopy of Russian Academy of Sciences, Troitsk, 142090,
Russia

2Odessa University, P.O.Box 24a, Odessa-9, 65009

We present the results of modelling generation of the atto-second VUV and X-ray
pulses

during ionization of atomic and cluster systems by femto-second optical laser
pulse. The

concrete data are received for the Ar cluster response, the molecular 2D H2+
response

for diŽerent inter nuclear distances (R=2.5, 3.5, 7.4, 16a.u.) with smoothed
Coulomb

potential and atomic (H) response (spectral dependence) under ionization of the
system

by femto-second optical pulse [1-4]. Our calculation show that the generation of
the atto-

second X-ray pulses in the cluster system is more eŽective and pro¯table (as
minimum

the 2-3 orders) than in similar molecular atomic one. The generation of the
atto-second

pulses in the molecular system is more pro¯table too (as minimum the 1-2 orders)
than

in similar atomic one. The last achievements in this ¯eld demonstrate a
possibility of

construction of the compact X-ray radiation sources.

References

[1] A. Glushkov, L.N. Ivanov, J. Phys.B. 26, L379 (1993)

[2] A. Glushkov, O. Khetselius, Recent Adv. in Theory of Phys. and Chem. Syst.

(Springer). 18 (2008)

[3] A. Glushkov, et al, Int. Journ. Quant. Chem. 99, 889 (2004)

[4] A. Glushkov, O. Khetselius, S. Malinovskaya, Mol. Phys. 24 (2008)

CP 73

95

Long-term stability of high- nesse Fabry-Perot

resonators made from Ultra-Low-Expansion glass

J. Alnis1, A. Matveev1;2, C. Parthey1, N. Kolachevsky1;2, T.W. Hansch1;3

1 MPI fur Quantenoptik, Hans-Kopfermann Str. 1, 85748 Garching, Germany

2 P.N. Lebedev Physics Institute, Leninsky prosp. 53, 119991 Moscow, Russia

3 Ludwig-Maximilians University,Geschwister-Scholl-Platz 1, 80539 Munich,
Germany

Sub-Hz line width lasers limited by thermal noise of the high- nesse Fabry-Perot
(FP) resonators

used for laser stabilization are very important for optical atomic clock
community.

Usually thermal noise limited operation can be achieved for time scales of
approximately

1 min and for longer time scales the drift starts to dominate. The most suitable
material

for making a stable FP cavity (spacer and mirror substrates) is Ultra Low
Expansion

glass (ULE). In this work we report on our observations of the long-term
stability of ULE

FP resonators measured against the hydrogen 1S-2S transition and also using an
optical

frequency comb referenced to a hydrogen maser.

When ULE FP cavity temperature is stabilized around the zero thermal expansion
point

the FP resonance frequency drift is very small and it is dominated by the aging
of the

cavity. Our 77.5 mm long ULE FP resonator that is stabilized at the zero
expansion

temperature [1, 2] has a temperature sensitivity of ca 20 Hz/mK and during 2
weeks of

measurements we could clearly observe a linear drift of +60(5) mHz/s (5 kHz/day)
at 972

nm due to FP aging while measuring an optical beat note with a stable optical
frequency

comb. During two 15 h long measurement runs the deviation from a linear drift
slope was

within 20 Hz (using 100 s counter gate time). It was also observed that,
unfortunately,

the drift rate slightly changed from day to day.

Our second 972 nm ULE FP cavity (length 77.5 mm) that is stabilized 20K above
the

optimal zero expansion temperature is having temperature stability of 11 kHz/mK
and

exhibits frequency uctuations in 20 kHz range per day that we attribute to the
stability

of the temperature control. When the temperature controller is activated it
takes

approximately 2 weeks for this ULE FP cavity resonance frequency to stabilize.

The resonance frequency of our oldest ULE FP resonator (length 15 cm) built in
2004 for

dye laser stabilization at 486 nm has been tracked against the hydrogen 1S-2S
transition

for 4 years now. It was observed that during the rst year the drift was +80
mHz/s

and at present it has decreased to +40 mHz/s at 486 nm. This can be explained by
the

relaxation of the cavity after mechanical machining. Positive frequency drifts
indicate

shrinking of the FP length.

References

[1] J. Alnis, A. Matveev, N. Kolachevsky, Th. Udem, and T.W. Hansch, Sub-Hz
line

width diode lasers by stabilization to vibrationally and thermally compensated
ultra low

expansion glass Fabry-Perot cavities, Phys. Rev. A, to appear 2008.
arxiv:0801.4199.

[2] J. Alnis, A. Matveev, N. Kolachevsky, T. Wilken, R. Holzwarth, T.W. Hansch,
Stable

diode lasers for hydrogen precision spectroscopy, Eur. Phys. J. D. Special
Topics, to

appear 2008.

CP 74

96

Application of Surface-Enhanced-Raman-Scattering

(SERS) for In-Situ Detection of PAHs in Sea-Water

Heinar Schmidt, Heinz-Detlef Kronfeldt

Institut für Optik und Atomare Physik, Technische Universität Berlin

Hardenbergstr. 36, 10623 Berlin, heinar@physik.tu-berlin.de

Enforced monitoring of sea-water requires advanced instrumentation and
technologies for

long term and unattended observation. In particular real time and in-situ
sensors are of

interest. In this field, sensors tragetting organic pollution are scarce.

We present a sensor based on surface-enhanced Raman scattering (SERS) using
disposable

SERS substrates as sensing membrane which have been designed for the in-situ
detection

of polynuclear aromatic hydrocarbons (PAHs). Raman spectroscopy was chosen due
to

the fingerprinting nature of the spectra useful for the identification of
organic substances

and SERS was applied to achieve the sensitivity for trace detection in the
environment.

The SERS sensor was developed as part of the EU-funded projects SOFIE
(Spectroscopy

Using Optical Fibres in the Marine Environment) and MISPEC (Multiparametric
insitu

Spectroscopic Measuring Platform for Coastal Monitoring) where a field-operable

device was constructed, characterised and field-tested in the Baltic Sea, at the
Atlantic

coast and in the Bosphorus. The underwater system consists (amongst other) of a
robust

SERS optode which is coupled to a core instrument containing a 785nm diode laser
and

an axial spectrograph with TE-cooled CCD detector.

We present results of laboratory tests characterising the SERS substrates in
terms of

selectivity, adsorption kinetics, adsorption from mixtures of up to eight PAHs
and limits of

detection for selected PAHs. The influence of salinity, flow conditions and high
immunity

against turbidity are shown. In-situ SERS and Raman spectra from the sea trials
will

be presented. The potential and limitations of Raman and SERS spectroscopy will
be

discussed with a view to marine in-situ applications.

CP 75

97

Laser Based Isotopic Separation of Atoms

Shahzada Qamar Hussain1, M. Saleem2, Dr. M. Aslam Baig

1Quaid-i-Azam University, Department of Physics, Islamabad

2COMSATS Institute of Information Technology, Department of Physics, Defence
Road

O Raiwind Road, Lahore, Pakistan

A design and fabrication of an atomic beam system is presented. The beam source
consists

of a cylindrical oven made of stainless steel enclosed by a cylindrical heater
for producing

the vapor of the sample in the oven [1,2]. The atomic beam source is simple,
versatile

and can be operated at stable temperatures up to 1000K. The atomic beam
apparatus is

placed inside the locally developed Time of Flight (TOF) mass spectrometer.
Interaction

of laser with the atomic beam in the interaction region of the TOF mass
spectrometer

produces ions that are resolved and detected by the TOF mass spectrometer. The
ob-

served signals from the TOF mass spectrometer are correlated with the ight times
for

di erent isotopic masses. The optimum performance of the atomic beam-TOF mass
spec-

trometer is checked with the isotope separation of lithium and magnesium. Their
relative

abundance is found very close to the already cited values in the literature.

The locally designed and fabricated atomic beam-TOF mass spectrometer is
therefore

capable for the spectroscopic studies of the selected isotopes of elements. The
apparatus

can be utilized for Laser isotopic separation of light elements possessing su
cient vapor

density up to 1000K.

References:

[1] "High temperature metal atomic beam sources", K.J. Ross and B. Sonntag, Rev.
Sci.

Instrum. 66(9), 4409 (1995).

[2] "High Temperature Materials and Technology", E. Compbell and E. M. Shewood,

Wiley, New York, (1967).

CP 76

98

Atomic °uorescence coupled into a thin optical ¯bre

D. Gleeson1;2, V. Minogin2;3;4 and S. Nic Chormaic1;2

1 Physics Department, University College Cork, Cork, Ireland

2Photonics Centre, Tyndall National Institute, Prospect Row, Cork, Ireland

3Dept. of Applied Physics and Instrumentation, Cork Institute of Technology,

Bishopstown, Cork, Ireland

4 Institute of Spectroscopy, Russ. Ac. of Sciences, 142190 Troitsk, Moscow
Region,

Russia

E-mail: danny.gleeson@tyndall.ie

In recent years there has been considerable interest in the problem of the
interaction be-

tween optically excited atoms and dielectric nanobodies. The basic aspects of
such an

interaction are the modi¯cation of the spontaneous emission rate near nanobodies
[1-3]

and the dependence of the coupling of atomic °uorescence to the nanobody on the
strength

of the interaction between the atoms and the surface of the nanobody. These
studies are

important for developing new spectroscopic techniques to measure interactions
between

atoms and nanobodies as well as developing new experimental schemes to control
internal

and translational atomic states near optical nanobodies [4, 5].

Here, we report on the spectrum of °uorescence emitted by optically excited
atoms into

the fundamental guided mode of an optical nano¯bre. An ensemble of two level
atoms

in the vicinity of a nano¯bre is considered. The atoms are excited by a laser
¯eld near-

resonant to the atomic dipole transition and emit °uorescent light. The
frequency of the

°uorescent light is chosen to be below the cut-oŽ frequency of all guided modes
bar the

fundamental, and so only this mode is generated by the °uorescent light.

We ¯nd that when an atom is far from the surface of the ¯bre it is most
eŽectively excited

by the laser ¯eld with a frequency close to the atomic transition for the free
atom. When

the atom is close to the surface of the ¯bre, we see that it is now excited at a
red-shifted

frequency. This shift leads to an asymmetry of the °uorescence line, observed as
the

power of light coupled into the nano¯bre. This selectivity can be used for
measuring the

strength of the interactions, including the evaluation of the van der Waals
constant. It

can also be used for the control of the atomic states near optical nano¯bers. We
evaluate

the atomic °uorescence spectrum for 133Cs atoms excited at the 6S-6P optical
transition

with wavelength 852 nm.

References

[1] T. Sondergaard and B. Tromborg, Phys. Rev. A 64, 033812 (2001)

[2] V. V. Klimov and M. Ducloy, Phys. Rev. A 69, 013812 (2004)

[3] Fam Le Kien, S. Dutta Gupta, V. I. Balykin, and K. Hakuta, Phys. Rev. A 72,
032509

(2005)

[4] V. I. Balykin, K. Hakuta, Fam Le Kien, J. Q. Liang, and M. Morinaga, Phys.
Rev. A

70, 011401 (R) (2004)

[5] K. P. Nayak, P. N. Melentiev, M. Morinaga, Fam Le Kien, V. I. Balykin, and
K.

Hakuta, Opt. Express 15, 5431 (2007).

CP 77

99

Nonlinear dynamics of atoms in a cavity:

The role of finite temperature effects

D.U.Matrasulov1, T.A.Ruzmetov1, D.M.Otajanov1, P.K.Khabibullaev1,

A.A.Saidov1 and F.C.Khanna2

1Heat Physics Department of the Uzbek Academy of Sciences,

28 Katartal Sreet, 100135 Tashkent, Uzbekistan

2Physics Department of the University of Alberta,

Edmonton, Alberta, T6G 2J1 Canada

E-mail: davrano@yahoo.com

Cavity quantum electrodynamics is an area of physics studying the interaction of

atoms with photons in high-finesse cavities in a wide range of the
electromagnetic spectrum

from microwaves to visible light. The fact that the system atom + cavity mode
is a quantum

system makes cavity quantum electrodynamics (QED) an excellent testing ground
for such

important issues of modern quantum physics as quantum measurement theory,
entanglement,

quantum computation, quantum interference and at the same time provides a unique

possibility for trapping, cooling and manipulating of atoms. Practical
importance of cavity

QED is mainly related to potential possibility for manipulating atoms and
photons in

mesoscopic scales. Therefore, in recent years cavity QED has become one of the
hot topics

both in theoretical and experimental physics [1- 3].

Since the dynamics of a single atom trapped in a microcavity is governed by
quantum

electrodynamics, the cavity QED can be considered as an interdisciplinary area.
Many

subfield of physics, such as quantum and atomic optics, cold atom physics,
physics of

nanosized systems and quantum information, may use important results of the
cavity QED.

Recently cavity QED is considered in the context of nonlinear dynamics [3].
Mapping

quantum equations of motion onto classical ones, for the Jaynes-Cummings
Hamiltonian,

which includes recoil motion of the atom, Prants et. al., explored phase-space
dynamics of the

atom interacting with a single cavity mode by analyzing Poincare surface
sections and

calculating Lyapunov exponents [3].

In this work we explore finite-temperature nonlinear dynamics of an atom coupled
to a

single mode of the cavity field. Applying the formalism of a real-time
finite-temperature field

theory to the Jaynes-Cummings Hamiltonian and using the same approach as that
used in we

have studied classical dynamics of the atom + cavity mode system in the
presence of

coupling to a thermal bath.

Using the temperature-dependence of the equations of motion, dependence of the

dynamics on heat-bath effects or finite temperature effects are considered. The
results show

that the dynamics is quite sensitive to the small changes of temperature. This
implies that

temperature of a thermal bath can be considered as an additional control
parameter for the

dynamics of an atom coupling to cavity modes.

References

[1] Cavity Quantum Electrodynamics. Edited by P.R.Berman, (Academic, New York
1994).

[2] Special Issue on Modern Studies of Basic Quantum Concepts. Phys. Scr., T76
(1998).

[3] S.V.Prants, M.Edelman, G.M.Zaslavsky, Phys. Rev. E., 66 046222 (2002).

CP 78

100

Storage of optical pulses in solids despite fast

relaxation

G.G. Grigoryan1, Y.T. Pashayan-Leroy2, C. Leroy2 and S. Gu´erin2

1Institute for Physical Research, 0203, Ashtarak-2, Armenia

2Institut Carnot de Bourgogne, UMR 5209 CNRS - Universit´e de Bourgogne, BP
47870,

21078 Dijon, France

The solid-state systems are very attractive for optical information storage due
to their

high density, compactness, and absence of diffusion. The main drawbacks of
solid-state

materials are huge inhomogeneous broadenings. In practice an efficient storage
of information

requires a large optical depth [1] such that even negligibly weak losses being

accumulated at such long distance result in an essential loss of information. In
order to

reduce the inhomogeneous broadening, it was proposed in a number of works to use
the

so-called hole burning technique [2]. However, this technique leads to the
reduction of the

optical depth of the samples employed. The natural question is whether it is
possible to

store optical information in solids using reduced optical depths.

Analytical studies performed in the limit of short pulses showed that the length
of information

storage in - type medium depends remarkably on the ratio between the oscillator

strengths of the adjacent transitions [3]. In the present work by exploiting
this property

we propose a novel scheme of short length storage in media featuring fast
relaxations.

We perform a complete analytical and numerical study of the full set of the
density-matrix

and Maxwell equations for both pulses in case of arbitrary relaxation times and
arbitrary

intensities of the probe and control fields in a - type medium. Our detailed
analysis

shows that the storage of the probe field in inhomogeneously broadened media is
more

efficient when we use atoms of different adjacent transition strengths. In this
case the

control pulse should have longer duration but considerably lower intensity than
the probe

pulse. The possibility of the retrieval of an intense pulses stored in a medium
is also

discussed.

References

[1] M. Fleischauer and M.D. Lukin, Phys. Rev. Lett. 84 , 5094 (2000); I.
Novikova, A.V.

Gorshkov, D.F. Phillips, A.S. Sørensen, M.D. Lukin, R.L. Walsworth, Phys. Rev.
Lett.

98, 243602 (2007).

[2] M.S. Shahriar, P.R. Hemmer, S. Lloyd, P.S. Bhatia, A.Craig. Phys. Rev. A 66,

032301 (2002); M. Nilsson, L. Rippe, S. Kroll, R. Klieber, D. Sutter, Phys. Rev.
B 70,

214116 (2004).

[3] G.G. Grigoryan and Y.T. Pashayan. Phys. Rev. A 64, 013816 (2001); G.G.
Grigoryan

and G.V. Nikoghosyan. Phys. Rev. A 72, 043814 (2005).

CP 79

101

Purcell-enhanced Rayleigh scattering into a

Fabry-Perot cavity

Michael Motsch, Martin Zeppenfeld, Gerhard Rempe, and Pepijn W.H. Pinkse

Max-Planck-Institut fÄur Quantenoptik, Hans-Kopfermann-Str. 1, 85748 Garching,

Germany

In recent years a growing interest in cold molecules from ¯elds as diŽerent as
cold chem-

istry, precision spectroscopy and quantum information science could be observed.
Velocity

¯ltering by means of an electrostatic quadrupole guide is an eącient technique
to produce

slow beams of polar molecules from a thermal reservoir. For formaldehyde,
ammonia, and

other naturally occurring polar molecules, °uxes of the order of 1010 s¡1 with
velocities

down to ť10 m/s with only a handful of occupied rotational states have been
demon-

strated [1,2]. However, so far no universal method was found to bridge the gap
from the

cold (ť1 K) to the ultracold (ˇ1mK) regime.

Standard laser cooling schemes fail for molecules due to their complex internal
level struc-

ture, and hence lack of a closed cycling transition. By replacing spontaneous
emission

with coherent scattering into an optical cavity, the need for a closed
transition can be cir-

cumvented [3]. To avoid excitation of the molecular system, operating in the
far-detuned

Rayleigh scattering regime is advantageous. Since Rayleigh scattering cross
sections are

small compared to typical resonant cross sections and because typical densities
of cold

molecular samples are limited, it is unclear if enough light can be scattered
into the cavity

to be detected. To achieve eŽective cooling, the power of the coherently
scattered light

must be signi¯cantly higher than for detection only.

We have set up a precursor experiment using room-temperature molecules to study
the

feasibility of cavity-enhanced detection and cooling of thin samples of cold
molecules. As

a ¯rst step in this direction, we plan to experimentally demonstrate that also
in the far-

detuned Rayleigh scattering regime an optical cavity can enhance the scattered
power.

In our experiment we use a high-power single-frequency cw-laser operating at
532nm as

a transverse pump beam for Rayleigh scattering into the optical cavity. By
changing the

cavity ¯nesse, the enhancement of the light scattered into the cavity mode
compared to

the free-space situation is shown. We study the polarization, pressure and pump
power

dependence of the Rayleigh scattered light into a single mode of the optical
cavity and

derive limits for a detectable density of cold polar molecules with the present
setup.

References

[1] T. Junglen, T. Rieger, S.A. Rangwala, P.W.H. Pinkse, and G. Rempe, Eur.
Phys. J.

D 31, 365 (2003).

[2] M. Motsch, M. Schenk, L.D. van Buuren, M. Zeppenfeld, P.W.H. Pinkse, and G.

Rempe, Phys. Rev. A 76, 061402R (2007).

[3] P. Horak, G. Hechenblaikner, K.M. Gheri, H. Stecher, and H. Ritsch, Phys.
Rev.

Lett. 79, 4974 (1997); D. Chan, A.T. Black, and V. Vuletiśc, Phys. Rev. Lett.
90, 063003

(2003); P. Maunz, T. Puppe, I. Schuster, N. Syassen, P.W.H. Pinkse, and G.
Rempe,

Nature 428, 50 (2004).

CP 80

102

Circular and elliptical dichroism effects

in two-photon disintegration of atoms and molecules

M. Ya. Agre

National University of Kyiv-Mohyla Academy, 04070, Kyiv, Ukraine

E-mail: magrik@ukr.net

Compact convenient for the analysis expressions for the cross sections
considerably simplify

studying the interaction of electromagnetic radiation with atomic systems and
allow us to

discover some fine effects. In present paper on the basis of the general
symmetry

considerations taking only into account the dipole approximation and without any
other

approximations used in atomic calculations we derive the compact invariant
expressions for

the angular distribution of photoelectrons escaping from atoms or molecules in
the process of

two-photon ionization and for the angular distribution of fragments forming
under twophoton

two-particle dissociation of molecules. The dependence on all geometric
parameters

the unit vector p determining the direction of photoelectron (photofragments in
the case of

dissociation) motion, k specifying the direction of propagation for the
electromagnetic

radiation and the unit complex vector e specifying polarization of the radiation
is

completely separated in the angular distributions in the form of scalar and
triple scalar

products of the vectors. The information of the intrinsic structure of the
atomic system is

included in few constant dynamic parameters of the system that can independently
be

calculated using the well-known approximations.

In case of atoms and optically inactive molecules the angular distributions
contain the term

linear in the pseudoscalar degree of circular polarization of the
electromagnetic radiation

ξ = ik ⋅ (e × e*) :

ξa Re[k ⋅ (p × e)(p ⋅ e*)] , (1)

where a is a scalar dynamic parameter of the atomic system. The term (1) leads
to the

interesting effect of elliptical dichroism in the angular distribution of
photoelectrons

(photofragments of the molecule): under elliptical polarization of the
radiation, 0<⎟ξ⎟<1, the

density of the particle flux depends on the sign of ξ, i.e., on the
clock-anticlockwise rotation

of the field strength of the electromagnetic wave. However, the term (1) does
not lead to the

circular dichroism because it vanishes in case of circular polarization of the
wave (⎟ξ⎟=1).

The dynamic parameter a in (1) has to change the sign under time reversion. This
T-oddness

can appear due to the scattering phase of the escaping particle and due to the
resonance level

width in case of the resonant two-photon disintegration of the atomic system.

In two-photon ionization or dissociation of optically active (chiral) molecules
the angular

distributions also include the additional terms linear in ξ:

),

5

( 1 2

1 2 b ξk ⋅p + b ξk ⋅ p p ⋅ e − (2)

where b1 and b2 are the pseudoscalar dynamic parameters of the chiral molecule.
The terms

(2) do not vanish in case of circular polarization and, therefore, lead to the
circular dichroism

in the angular distributions.

The expressions for the angular distributions derived here could also be useful
for the

solution of inverse problem finding the atomic dynamic parameters from the
experiment.

CP 81

103

Thermal ionization of alkali Rydberg atoms

I. L. Glukhov and V. D. Ovsiannikov

Department of Physics, Voronezh State University, University Square 1, 394006,
Russia,

Voronezh

E-mail: GlukhovOfficial@mail.ru

The environmental blackbody radiation (BBR) is a principal factor reducing
essentially

lifetimes of Rydberg atoms. Of the three channels of the BBR-induced level
broadening

decay to lower levels, excitation to upper levels and ionization the latter
is the

most destructive one, responsible for the neutral gas breakdown and for
supporting the

ionized state of plasmas. Therefore, the rate of the BBR-induced ionization of
atoms

from Rydberg states is an important characteristic for describing both the
elementary

processes in excited atoms and the kinetics of non-equilibrium gases and
plasmas.

We have calculated matrix elements for bound-free transitions in the dipole
approximation

for alkali atoms (Li, Na, K, Rb, Cs) on the basis of the Fues model potential
method [1].

The matrix elements were used for determining the rates of the BBR-induced
ionization

from s-, p-, d-states with the principal quantum number n=845 at different
temperatures.

Our results agree well with the latest available theoretical and experimental
data [2,3].

We discovered that the ratio En/kT for the states of maximal ionization rate
takes the

values in the range of 0.51.3. Therefore, we suggest the relation of an
effective principal

quantum number , corresponding to the maximal photoionization rate, with the
ambient

temperature T (in Kelvin)

= (350 ÷ 560) T−1/2, where En = −

1

2 2 .

We also generalize our previously reported three-term approximation [4], which
was proposed

for helium, to the alkali atoms. Thus, the BBR-induced ionization rate Pn in
inverse

seconds is

Pn =

a0 + a1x + a2x2

4[exp(x) − 1]

, where x =

1.579

2T

105 ,

and ai are fitted coefficients, for a given atomic series of states, smoothly
dependent on

temperature. This equation provides good results for states in the vicinity of
the ionization

rate maximum and for higher energy states. The deviation of results determined
by

this approximate equation from those of exact calculations for the states with
principal

quantum numbers up to n = 70 does not exceed 15%.

The temperature dependence for a-coefficients is approximated by the relation

ai =

P2

k=0

bikT−k/2,

with nine coefficients bik, fixed for each series, providing rather accurate
results in the

ranges of T =1002000K.

References

[1] N.L. Manakov, V.D. Ovsiannikov, L.P. Rapoport, Phys. Rep. 141, 319433
(1986)

[2] I.I. Beterov, D.B. Tretyakov, I.I. Ryabtsev, Phys. Rev. A 75 052720 (2007)

[3] I.I. Beterov, I.I. Ryabtsev, D.B. Tretyakov, JETP to be published (2008)

[4] I.L. Glukhov, V.D. Ovsiannikov, Proc. of SPIE 6726, 67261F (2007)

CP 82

104

Hyperpolarizabilities of multiplet Rydberg states in

alkali and alkaline-earth atoms

V.D. Ovsiannikov 1 and E.Yu. Ilinova 1

1 Department of Physics, Voronezh State University, 394006 Voronezh, Russia

The atomic spectra in external ¯elds is one of the most important problems of
atomic

Physics and spectroscopy. Sensitive methods were developed for cooling and
trapping

atoms, for selective excitation to strictly indicated states, for experimental
investigation

of radiative properties of atoms in Rydberg states [1,2]. The spectroscopy of
atoms and

atomic ensembles trapped in optical lattices provides new information on the
properties of

quantum objects and on elementary processes of radiation-matter interaction.
Precision

information on the Stark eŽect in higher orders of perturbation theory is of a
special inter-

est in constructing optical frequency standards of a new generation, and also in
processing

quantum information on the basis of atomic ensembles in Rydberg states.
Therefore, the

development of simple methods for calculating nonlinear atomic susceptibilities,
speci¯-

cally those for Rydberg states, seems of primary importance.

Stark shifts of energies for Rydberg SJ ; PJ ;DJ (J=L§S) states of alkali
(S=1=2) and

alkaline-earth (S=0; 1) atoms in external electric ¯eld were determined, up to
the 4-th

order in the ¯eld strength. To this end, for close sublevels of multiplets, with
equal

values of magnetic quantum number MJ , the higher-order perturbation theory for
nearly-

degenerate states [3] was used. Analytical equations for energy shifts were
presented in

terms of irreducible (scalar and tensor) parts of polarizabilities Žs;t,
hyperpolarizabilities

°s;t2;t4 and oscillator strength sums ¯s;t [3]. For irreducible parts of
hyperpolarizabilities

and oscillator strength sums the three-term approximation in powers of the
eŽective prin-

cipal quantum number º=1=

p

¡2Enl was proposed, which provides accurate estimates to

these values for Rydberg states with arbitrary principal quantum number, up to º
= 1000.

The coeącients of the polynomials were obtained from the corresponding values,
calcu-

lated for states with the radial quantum number nr = 25; 26; 27.

Using the calculated data, the "critical" values of ¯eld intensities for double
Stark reso-

nance on Rydberg 36P3=2;1=2; 37S1=2; 37P3=2;1=2 states in Na were determined and
compared

with experimental and theoretical data of ref.[1]. The account of the 4-th-order
terms

amends the agreement with experimental data so, that the diŽerence from the
results of

ref. [1] does not exceed 1-1.5 percents. Also, for Rb atom, on the basis of our
data and

the results previously obtained in [4], the coeącients were determined, which
appear at

F4 in expansion of energy shifts in powers of ¯eld intensity. The data of
calculations

demonstrates signi¯cant amendments of agreement between theoretical and
experimental

data in comparison with that of the ref. [2].

References

[1] I.I. Ryabtsev, D.B.Tretyakov, JETF 121 787 (2002).

[2] T.Haseyama, K.Kominato, M.Shibata, S.Yamada, T.Saida, T.Nakura, Y.Kishimoto,
M.Tada,

I.Ogawa, H.Funahashi, K.Yamamoto, S.Matsuki, Phys.Lett. A 317 450 (2003).

[3] I.L. Bolgova, V.D. Ovsiannikov, V.G. Palchikov, A.I. Magunov, G. von Oppen,
JETF 123

1145 (2003).

[4] A.A. Kamenski, V.D. Ovsiannikov, J.Phys B:At. Mol.Opt.Phys. 39 2247 787
(2006).

CP 83

105

Penning ionization of cold Rb Rydberg atoms due to

long-range dipole-dipole interaction

N. N. Bezuglov1;2, K. Miculis1, A. Ekers1, J. Denskat3, C. Giese3, T. Amthor3,
and

M. WeidemÄuller3

1 Laser Centre, University of Latvia, LV-1002 Riga, LATVIA

2 Faculty of Physics, St.Petersburg State University, 198904 St. Petersburg,
RUSSIA

3 Physikalisches Institut, UniversitÄat Freiburg, D-79104 Freiburg, GERMANY

Ionization in cold collisions of Rydberg atoms is possible via two mechanisms:
associative

and Penning ionization. Associative ionization is a short range process of low
eąciency,

because it requires close encounters enabling overlap of Rydberg atom
wavefunctions (at

internuclaer distances R ¿ n¤2). In contrast, Penning ionization is a long-range
process

(at R À n¤2), which is enabled by the dipole-dipole interaction (atomic units
are used in

this abstract)

V =

~D

1~D2 ¡ (~D1~n)(~D2~n)

R3 ; (1)

where ~Di are the dipole moments of both atoms and ~n denotes the orientation of
the

internuclear axis.

We consider the formation of atomic ions in an Ager-type processes: one of the
Rydbrg

atoms undergoes a dipole transition from the initial state nl to a lower state
n0l0, while

the other atom is excited form the initial state nl to the ionization continuum.
Such

ionization can take place if the energy released in the nl ! n0l0 transition is
equal to (or

larger than) the binding energy of electron in the nl state, which is given by
the condition

n¤0

< n¤=

p

2 (n¤ is the eŽective quantum number). Perturbation theory [1] allows one to

express the autoionization width ¡(R) via the photoionization cross section ¾ph
of atom

in the nl state and the reduced dipole matrix elements jDnn0 j of the nl ! n0l0
transitions

¡(R) =

e¡

R6 ; e¡ =

X

n0

c¾ph

¼!nn0

jDnn0 j2 (2)

We have evaluated the ionization rates e¡ using semiclassical analytical
formulae for both

the photoionization cross sections and the dipole matrix elements derived in [2]
for alkali

atoms. The resulting e¡(n¤) is a function that oscillates around the power-law
curve

e¡

= Cn¤16=3 with CS = 0:3 and CP = 0:46 for nS and nP states, respectively. These

results should help in understanding the ionization dynamics of cold Rydberg
gases [3].

Support by the EU FP6 TOK Project LAMOL, DFG, and ESF is acknowledged.

References

[1] K. Katsuura, J.Chem.Phys., 47, 3770 (1965).

[2] N. N. Bezuglov, V. M. Borodin, . Opt. Spectrosc., 86, 467 (1999).

[3] T. Amthor, M. Reetz-Lamour, C. Giese, and M. WeidemÄuller, Phys. Rev. A 76,

054702 (2007).

CP 84

106

Ionization of alkali-metal Rydberg atoms

by blackbody radiation

I.I.Beterov1, I.I.Ryabtsev1, D.B.Tretyakov1, N.N.Bezuglov2, A.Ekers3, and
V.M.Entin1¤

1Institute of Semiconductor Physics, Pr. Lavrentyeva 13, 630090, Novosibirsk,
Russia

2Institute of Physics, 198904, St. Petersburg, Russia

3Institute of Atomic Physics and Spectroscopy, LU, LV-1586 Riga, Latvia

E-mail: ¤ventin@isp.nsc.ru

Interaction of Rydberg atoms with blackbody radiation (BBR) was studied for many

years [1]. However, only few works were devoted to BBR-induced ionization of
Rydberg

atoms. A renewed interest to this process is related to the recently observed
spontaneous

formation of ultracold plasma in dense samples of cold Rydberg atoms and to the
prospects

of using the BBR ionization as a convenient reference signal in absolute
measurements of

collisional ionization rates.

In this report the results of our extended theoretical calculations of
BBR-induced ion-

ization rates of alkali-metal Rydberg atoms are presented [2,3]. Calculations
have been

made for nS, nP and nD states of Li, Na, K, Rb and Cs atoms, which are commonly
used

in a variety of experiments, at principal quantum numbers n=8-65 and at three
ambient

temperatures of 77, 300 and 600 K. A semi-classical model [4] was used to
numerically

calculate the bound-bound and bound-free matrix elements. A peculiarity of our
calcu-

lations is that we take into account the contributions of BBR-induced
redistribution of

population between Rydberg states prior to photoionization and ¯eld ionization
by ex-

traction electric ¯eld pulses. The obtained results show that these phenomena
aŽect both

the magnitude of total ionization rates and shapes of their dependences on the
principal

quantum number n. For Li Rydberg atoms a bound-bound Cooper minimum is observed.

The theoretical ionization rates are compared with the results of our earlier
measurements

of BBR-induced ionization rates of Na nS and nD Rydberg states with n=8-20 at
300 K.

A good agreement for all states except nS with n>15 is obtained. The useful
analytical

formulas for quick estimates of BBR ionization rates taking into account quantum
defects

of Rydberg atoms are also presented. These formulas have been derived using the
ana-

lytical formulas for hydrogen matrix elements obtained in [5]. The analytical
estimates of

BBR-induced ionization rates well agree with the results of our numerical
calculations.

This work was supported by the Russian Academy of Sciences, EU FP6 TOK project

LAMOL, European Social Fund, Latvian Science Council, and NATO grant
EAP.RIG.981387.

References

[1] T.F.Gallagher, "Rydberg Atoms", Cambridge University Press, Cambridge
(1994).

[2] I.I.Beterov, D.B.Tretyakov, I.I.Ryabtsev, N.N.Bezuglov, and A.Ekers, Phys.
Rev. A,

2007, v.75, p.052720.

[3] I.I.Beterov, I.I.Ryabtsev, D.B.Tretyakov, N.N.Bezuglov, and A.Ekers, JETP,
2008 (in

press).

[4] L.G.Dyachkov and P.M.Pankratov, J. Phys. B, 1994, v.27, p.461.

[5] S.P.Goreslavsky, N.B.Delone, and V.P.Krainov, JETP, 1982, v.55, p.246.

CP 85

107

Level-crossing transition between mixed states

B. T. Torosov and N. V. Vitanov

Department of Physics, So¯a University, James Bourchier 5 blvd, 1164 So¯a,
Bulgaria

The Landau-Zener model [1] is conventionally used for estimating transition
probabilities

in the presence of crossing levels. Nevertheless, because of the in¯nite
duration of the

coupling in this model, the propagator involves a divergent phase. It has been
shown that

this phase causes unde¯ned populations in the degenerate Landau-Zener model
[2].In this

work we show that even in the original Landau-Zener model we have unde¯ned
populations

when we deal with pure superposition states or with mixed states. Besides, we
show that

the Allen-Eberly model [3] can be used as an alternative to the Landau-Zener
model to

describe the dynamics of such level-crossing problems.

References

[1] L. D. Landau, Physik Z. Sowjetunion 2, 46 (1932); C. Zener, Proc. R. Soc.
Lond. Ser.

A 137, 696 (1932).

[2] G. S. Vasilev, S. S. Ivanov and N. V. Vitanov, Phys. Rev. A 75, 013417
(2007).

[3] L. Allen and J. H. Eberly, Optical Resonance and Two-Level Atoms (Dover, New
York,

1987).

CP 86

108

M1-E2 interference in the Zeeman spectra of Bi I

S. Werbowy and J. Kwela

Institute of Experimental Physics, University of Gdansk, Wita Stwosza 57, 80-952

Gda´nsk, Poland

Precision in atomic parity nonconservation (PNC) measurements have reached the
level

required to provide important tests of the electroweak standard model [1].
Nevertheless,

to extract the electroweak quantity of interest, the weak charge, from the
experiment,

atomic structure calculations of comparable precision are necessary. The
measurement of

the ratio D = AE2/(AE2+AM1) of the electric-quadrupole (E2) and magnetic-dipol
(M1)

transition probabilities in mixed forbidden lines can provide stringent test of
theoretical

wave-function calculations; accurate knowledge of this quantity is essential for
existing

and future measurements of parity nonconserving optical rotation.

The 6s26p3 ground configuration of bismuth gives rise to five levels 4S3/2,
2P3/2,1/2

and 2D5/2,3/2. We report studies [2] of the interference effect in mixed-type
forbidden

lines: 461.5nm (2P1/2 →4S3/2), 647.6nm (2D5/2 →4S3/2) and 875.5nm (2D3/2 →4S3/2)
of

Bi I. In the past, the mixed M1+E2 type lines 647.6nm and 875.5nm in bismuth
were

intensely exploited in PNC experiments [3, 4]. In the Zeeman effect of mixed
multipole

lines, the intensities of patterns are not a simple sum of two contributions for
M1 and E2

radiations taken in proportion to their transition probabilities, but should be
modified by

an interference term. The spontaneous transition probability for a single photon
emission

in the presence of the magnetic field can be expressed, according to

aab = (1 − D)aM1

ab + DaE2

ab

ą 2 D(1 − D)aM1−E2

ab , (1)

where D is percentage admixture of E2 radiation, aM1

ab and aE2

ab are pure magnetic-dipol

and electric-quadrupole components, respectively, and the cross term aM1−E2

ab describes

the interference effect. The interference effect in emission spectra causes the
difference

between the intensities of ΔM=ą1 Zeeman patterns observed in longitudinal and
transverse

directions of observation. This phenomenon, in a series of experiments, was used

for precise determination of the electric-quadrupole admixture D in forbidden
lines.

A special computer program considering the M1-E2 interference was design to
obtain

the predicted contour of the Zeeman structure of the line. By variation of free
parameters,

describing the line shape and electric-quadrupole admixtures, the calculated
profiles were

fitted into the experimental spectra recorded by CCD detector. The E2 admixtures
found

are: (7.84ą0.14)%, (17.5ą0.4)% and (0.70ą0.11)% for 461.5nm, 647.6nm and 875.5nm

lines, respectively. Our results were compared with recent theories and other
experiments.

This work was supported by grant BW/5200-5-0482-8 and BW/5200-5-0053-8.

[1] C. S. Wood, at. al., Science 275, 1759 (1997)

[2] S. Werbowy and J. Kwela, Phys. Rev. A 77, 023410 (2008)

[3] P. E. G. Baird, at. al., Phys. Rev. Lett. 39, 798 (1977)

[4] J. H. Hollister, at. al., Phys. Rev. Lett. 46, 643 (1981)

CP 87

109

Numerical investigation of NeI for 2p55g configuration

and ArI for 3p55g configuration Zeeman structure

Anisimova G.P.1, Efremova E.A.1, Semenov R.I.1, Tsygankova G.A.1

1St.-Petersburg State University

Petergof, Ulianovskaja st., 1, NIIF-SPbSU, St.-Petersburg, 198504, Russia.

E-mail: efremovakat@inbox.ru

The behavior of an atom in the magnetic field can be studied numerically based
on the

parameters of the fine structure (the radial integrals in the energy operator
matrix). A

set of the fine structure parameters ensuring the correlation with
experimentally observed

energies [1; 2] was obtained in the previous works of the authors.

The authors provide the results of the numerical study of magnetic sublevels
behavior for

NeI and ArI (of specified configurations) in the magnetic fields up to 150 kOe.

Using the free momentums representation and the Clebsch-Gordan coefficients the
authors

succeeded to obtain the expressions for the diagonal and non-diagonal elements
of the

atom-field interaction matrices in LSJM-representation as well as to refine the
signs of

the non-diagonal elements.

h ijWj ii =

J(J + 1) + L(L + 1) S(S + 1)

2J(J + 1) gl + J(J + 1) L(L + 1) + S(S + 1)

2J(J + 1) gs

0HM

( J = L = S = 0)

h ijWj 0 ji =

s

(J L + S + 1)(J + L S + 1)(J + L + S + 2)(L + S J)

4(J + 1)2(2J + 1)(2J + 3)

((J + 1)2 M2)

(gl gs) 0H

( J = 1, L = S = 0, Jmin)

The energies of Zeemans sublevels were calculated by means of the
diagonalization of

the complete energy operator matrix, which was expressed in LS-representation
with

additional elements accounting for the atom-field interaction. The
diagonalization was

carried out for all the values of the magnetic quantum number M.

The distinctive details of Zeemanns structure especially points of crossing and
anticrossing

areas of magnetic sublevels were obtained for 2p55g configuration of NeI and
3p55g

configuration of ArI.

References

[1] Chang E.S., Schoenfeed W.G., Biemont E., Quinet P., Palmeri P., Phys. Scr.
V. 49.,

26-33 (1994)

[2] Palmeri P., Biemont E., Phys. Scr. 1995. V. 51., 76-80 (1995)

CP 88

110

Method for quantitative study of atomic transitions

in magnetic ¯eld based on vapor nanocell with L =¸

A. Papoyan1,G. Hakhumyan1;2, A. Atvars3, M. Auzinsh3 and D. Sarkisyan1.

1 Institute for Physical Research, NAS of Armenia, Ashtarak-0203, Armenia

2 Russian-Armenian State University, 123 Hovsep Emin str., Yerevan, 0051 Armenia

3 Department of Physics, University of Latvia, 19 Rainis blvd., Riga, LV-1586
Latvia

E-mail: papoyan@ipr.sci.am

It is well known that atoms placed in an external magnetic ¯eld undergo shift of
their

energy levels and change in their transition probabilities. To study these
changes, widely

used saturation absorption technique has been used in [1]. However, the
complexity of

Zeeman spectra in magnetic ¯eld arises primarily from the presence of strong
crossover

resonances, which are also split into many components strictly limiting the
range of study

to 5 ¥ 50 G, while the most signi¯cant changes are expected for B ť 1000 G.

A method, which we call " L =¸ Zeeman technique" (¸ -ZT) has been implemented
for

investigation of the individual transition between the Zeeman sublevels of the
hf structure

of alkali atoms in magnetic ¯eld 1 ¥ 2500 G. The ¸-ZT is based on the employment
of

a nanocell with the thickness of Rb vapor column equal to the wavelength of
diode laser

radiation resonant with D2 line of atomic 85Rb, 87Rb (¸ = 780 nm). At the laser
intensity

1 mW/cm2, narrow ( ť 10 MHz) resonant velocity selective optical
pumping/saturation

(VSOP) peaks of reduced absorption appear in the transmission spectrum localized
ex-

actly at the atomic transitions [2]. These VSOP peaks are split to separate
components

in magnetic ¯eld; the amplitudes (which are proportional to transition
probability) and

frequency positions of the components depend on B - ¯eld.

Particularly, it is revealed that in relatively weak magnetic ¯eld (ť 100 G)
with ¾+-

polarized laser radiation also those atomic transitions are recorded, for which
new selec-

tion rules with respect to the quantum number F take place: 87Rb D2, Fg=1, mF= 1

Fe=3, mF=0 transition (let call it (2)) increases with the increase of the
magnetic ¯eld,

and at B ť 200 G becomes equal to probability of the strongest transition Fg=1,
mF=+1

Fe=2, mF=+2 (let call it (1)) for B = 0. At higher magnetic ¯eld up to 2000 G
probabil-

ity of the atomic transition (2) is the largest, while for B > 2000 G again the
probability

of (1) is larger than that of (2). Note that implementation of ¸-ZT technique is
very

convenient to study atomic transitions behavior also at higher magnetic ¯eld >
2000 G.

Particularly, by measuring the frequency diŽerence between transition (1) and
transition

(2) it is possible to measure a strongly non-homogeneous magnetic ¯eld of 150
G/mm.

This is achieved by displacement of the nanocell by 10 - 20 ¹m in the direction
of magnetic

¯eld gradient. The theoretical model very well describes the experimental
results.

Also, the performed studies showed that the atomic transition Fg=1 ! Fe=2 of
87Rb D1

line (¸ = 794 nm) is very convenient for determination of uniform, as well as
strongly

non-uniform magnetic ¯eld strength in the range of 5 ¥ 10 000 G.

References

[1] M.U. Momeen, G. Rangarajan, P.C. Deshmukh, Journ. Phys. B: At. Mol.Opt.
Phys.

40, 3163 (2007).

[2] C. Andreeva, S. Cartaleva, L. Petrov, S.M. Saltiel, D. Sarkisyan, T.
Varzhapetyan, D.

Bloch, M. Ducloy, Phys. Rev. A 76, 013837 (2007).

CP 89

111

g factor of boronlike ions

D. A. Glazov1, A. V. Volotka2, V. M. Shabaev1, I. I. Tupitsyn1 and G. Plunien2

1 Department of Physics, St. Petersburg State University, Oulianovskaya 1,

Petrodvorets, St. Petersburg 198504, Russia

2 Institut fur Theoretische Physik, TU Dresden, Mommsenstra e 13, D-01062
Dresden,

Germany

E-mail: glazov@pcqnt1.phys.spbu.ru

High-precision measurements of the g factor of H-like carbon and oxygen,
performed by

the GSI - Universitat Mainz collaboration, combined with the corresponding
theoretical

investigations, have provided a new determination of the electron mass to an
accuracy that

is four times better than that of the previously accepted value. An extention of
the g factor

experiments to higher-Z systems is anticipated in the near future at the HITRAP
facility

at GSI (Darmstadt). As was demonstrated in [1], investigations of a speci c di
erence

of the g factors of H- and B-like ions can provide an independent determination
of the

ne structure constant to an accuracy comparable to that of the recent
determination by

Gabrielse et al. [2].

We perform accurate calculations of the ground-state g factor of B-like ions in
a wide range

of nuclear charge numbers. The calculational methods were already employed in
[3,4] for

Li-like ions. One-loop QED corrections were evaluated in e ective screening
potential. To

our best knowledge, this is the rst correct evaluation of the QED correction to
the g factor

of the 2p state. The one-photon exchange correction was calculated in the
framework of

QED. The large-scale con guration-interaction Dirac-Fock-Sturm method was
employed

to take into account the electron-correlation e ects of the order 1=Z2 and
higher. As a

result, the most accurate up-to-date values of the g factor of B-like ions are
obtained.

References

[1] V. M. Shabaev et al., Phys. Rev. Lett. 96 (2006) 253002.

[2] G. Gabrielse et al., Phys. Rev. Lett. 100 (2008) 120801.

[3] D. A. Glazov et al., Phys. Rev. A 70 (2004) 062104.

[4] D. A. Glazov et al., Phys. Lett. A 357 (2006) 330.

CP 90

112

Magnetoelectric Jones spectroscopy

of Li and Na atoms

V.V.Chernushkin, V.D.Ovsiannikov

Theoretical Physics Dept, Voronezh State University, Voronezh, Russia,

E-mail:albert@phys.vsu.ru

Magnetoelectric birefringence, which was predicted by Jones1 and ¯rst observed
in liq-

uids2, may also become a useful tool for high-precision laser spectroscopy of
atomic sys-

tems3.

The amplitude of the Rayleigh scattering of a monochromatic wave with the
frequency

! = EnDJ ¡ EnS1=2 ¡ "J in resonance (j"J j ¿ !) with the D-level doublet
substates of

the total momentum J = 3=2; 5=2, may be written as (taking into account only the
terms

with the second-order resonance singularities)

U = AQ

Ã

7

("3=2)2 +

47

("5=2)2

¡

4

"3=2"5=2

!

['0 + '1]; (1)

where the constant factor A = F2F0B=1500 is proportional to the product of the
square

laser ¯eld F2, static electric ¯eld F0 and magnetic ¯eld B. The
polarization-dependent

factors are

'0 = (e0 ¢ [n £ eB]) ; '1 = Ref(e0 ¢ e) (e¤ ¢ [n £ eB])g;

where eB and e0 are unit vectors of magnetic and electric ¯elds, e and n are
unit po-

larization and wave vectors of the laser wave. The complex quantities "J = ¢J ¡
i¡J=2

include both the resonance detuning ¢J for the real part and the resonance level
width ¡J

for the imaginary part. The factor QD is a product of the radial matrix elements
for the

¯rst-order quadrupole and second-order dipole radiation transition between the
ground

nS1=2 and resonance n0D states (the in°uence of the ¯ne structure on radial
integrals is

neglected):

QD = hnSjr2jn0DJ2ihn0DJ1 jr(g!

P + g0

P )rjnSi;

The Jones birefringence appears, when e0 = eB, due to the diŽerence between the
ampli-

tude (1) for e = e(+) and e = e(¡), where e(§) = (e0 § [n £ e0])=

p

2:

¢U(J)

D = U(+)

D ¡ U(¡)

D = 2AQD

Ã

7

("3=2)2 +

47

("5=2)2

¡

4

"3=2"5=2

!

:

Similar eŽects in atoms with singlet structure of levels, which correspond to
"3=2 = "5=2,

were discussed in4.

1R. C. Jones, J. Opt. Soc. Am. 38, 671 (1948).

2T. Roth and G. L. J. A. Rikken, Phys. Rev. Lett. 85, 4478 (2000).

3D. Budker and J. E. Stalnaker, Phys. Rev. Lett. 91, 263901 (2003).

4P. V. Mironova, V. V. Tchernouchkine, V. D. Ovsiannikov, J. Phys. B, 39, 4999
(2006).

CP 91

113

Radiative transition probabilities from D Stark states

in orthohelium

A. A. Kamenski1 and V. D. Ovsiannikov1

1Department of Physics, Voronezh State University, 394006, Voronezh, Russia

The dependence of radiative line intensity on external ¯eld strength is an
important

characteristic of radiative properties, which gives rise to new lines in the
emission and

adsorption spectra and in suąciently strong ¯elds removes a number of lines that
exist

in the spectrum of a free atom. Our calculations for the pair-wise interacting
sublevels

were based on the integral SchrÄodinger equation for close levels [1]. The total
momenta

projection M determines a group of multiplet sublevels interacting with one
another in

the lowest order of external DC electric ¯eld. Even for a general case of
arbitrary angular

L and spin S momenta, one can ¯nd the states interacting in pairs. General
analysis of

diŽerent pairwise interacting substates with equal parity demonstrates common
features of

the ¯eld-dependent probability behaviour. In particular, we discovered the
equalization of

probabilities in the anticrossing ¯eld and vanishing of one of the two doublet
components

in a strong-¯eld limit [1].

In this communication we present some results on the radiative transitions from
triple-

interacting sublevels of atoms in a DC electric ¯eld. The perturbation operator
matrix

takes into account the interaction of an atom with a dc ¯eld in all orders of
the ¯eld

amplitude. The atomic wavefunction in the ¯eld is reduced to a set of
homogeneous

algebraic equations for the superposition coeącients [1,2].

The simplest example of triple-interacting sublevels are D-states of orthohelium
atom

with M = §1. We calculate numericaly energy shift and wave function
superposition

coeącients for this case in the ¯rst nonvanishing order of perturbation theory.
As for the

pair-wise interacting levels, the sign of the tensor polarizability determines
the behaviour

of triplet states in the ¯eld. So the sublevels approaching each other in
orthohelium

atom, as ¯eld strength increases, occurs only in 3D-state with positive tensor
part of

polarizability Žt

3D>0, and does not appear for nD-states with n ¸ 4 where Žt

nD<0 [2].

In order to reveal the impact of the anticrossing eŽect explicitly, we consider
the ¯eld

dependence of the probability of radiative transition from the
triple-interacting n 3D-levels

to an isolated n0 3PJ-sublevel (with J = 1;M = 0 or J = 2;M = §2) or to n0
3F3-sublevel

with M = 0. Such transitions give triplet structure of corresponding radiative
lines.

The vanishing of some ¯ne-structure components with the growth of the ¯eld
strength

corresponds to our asimptotic results for orthohelium lines [1].

Such dependence is not monotonous, and we discovered zero-intensity points and
intensity

maximum among the ¯ne-structure P ¡ D-lines. This eŽect can be useful for
selective

control by a dc ¯eld of the radiation processes.

References

[1] A.A. Kamenski, and V.D. Ovsiannikov, Journal of Experimental and Theoretical

Physics, 100, No 3, pp.487-504 (2005)

[2] A. A. Kamenski and V. D. Ovsiannikov, J. Phys. B: At. Mol. Opt. Phys. 39,

2247-2265 (2006)

CP 92

114

Light-induced quasi-static polarization in

hydrogen-like atom under the action of strong

electromagnetic laser field

M.V.Ryabinina, L.A.Melnikov

Saratov State Univerisity, Physics Department

83 Astrakhanskaya, 410012, Saratov, Russia

mvr@vtt.net

For two-level system is well known that the transitions rate parameter is
Rabi-frequency.

At large intensities the Rabi frequency can be comparable with an optical
transition

frequency ν, while laser electric field remains smaller than intra-atomic field.
In this case

temporal variation of probability amplitudes a(t) and b(t) for the levels of
two-level system

can occurs at frequencies comparable with nν, n = 1, 2, . . .. As a result,
simple analytical

solution is not possible and use of numerical methods [1] is required even for
two-level

system.

In present paper the transitions in hydrogen atom induced by the linearly
polarized pulse

with a polarization along the axis z are investigated. For hydrogen atom all
matrix

elements of transitions are in an analytical form as well as wave functions of
discrete and

continuum spectra. The dynamics of populations of 4s and 3p states and
polarization

of the transition 4s ↔ 3p are investigated theoretically and numerically at one-
, twoand

three-photon resonance conditions and at large detuning out of frame of
perturbation

theory and rotating wave approximation.

It was shown that at resonance the low frequency modulation of optical
oscillations exists,

producing corresponding quasi-static polarization of atoms along z-axis. The
oscillations

frequency becomes zero at the values of laser field amplitude corresponding to
ratio of Rabi

frequency to optical frequency ℘E0/ν = 1.05, 2.75, 4.3, 5.8, 7.5, 9, . . . These
low-frequency

oscillations are attributed to the special displacement of quasi-energy levels.
We have

used the Floquet-type solution of the equations for probability amplitudes:

i ˙a = ℘abb(t)E0(t) cos (νt) exp(iνt), i˙b = ℘aba(t)E0(t) cos (νt) exp(−iνt).
(1)

a(t) = exp(iλt)

∞

n=−∞

an exp (iνnt), b(t) = exp(iλt)

∞

n=−∞

bn exp (iνnt).

(iλ + iνn)an = −i

℘abE0(t)

2

(bn + bn−2), (iλ − iνn)bn = −i

℘abE0(t)

2

(an + an+2). (2)

Calculations of the values of λ gives λ = 1

2 for mentioned values of field. In this

case the quasi-levels are crossed. For two-photon transitions λ = 0(nν) for
℘E0/ν ≈

2.4, 4.1, 5.7, . . . demonstrating the same behavior of the polarization.

This effect can be used for measuring the ultra-high intensity pulse amplitudes.
The

influence of the transitions to continuum calculated using method of Ref.2 is
discussed

also.

References

[1] Bordyug N.V. and Krainov V.P. Laser Phys. Lett. v.4, 418(2007)

[2] Ryabinina M.V., Melnikov L.A. AIP Conference Proc. v.796, 325(2005)

CP 93

115

Doppler-free spectroscopy of rubidium atoms placed

in a magnetic field

G. Skolnik, N. Vujicic, T. Ban, S. Vdovic and G. Pichler

Institute of Physics, Bijenicka 46, Zagreb, Croatia

Saturation spectroscopy (SAS) is one type of high resolution laser spectroscopy
and is

widely used in alkali atomic vapour system for observing the sub-Doppler
resonances [1].

In SAS technique two counter-propagating laser beams, which derive from the
single laser

source, simultaneously interact with zero velocity group of atoms. The pump
laser beam

burns a hole in the Boltzmann distribution curve of the lower level and when the
probe

laser beam comes across this hole, in the absorption spectrum a Lamb dip can be
observed.

This dip has a Doppler-free Lorentzian line shape depending on the natural,
collision and

the transit time broadening and on the laser linewidth.

In this work we used saturation spectroscopy and improved it with an application
of a

lock-in technique. This technique eliminates broad Doppler-background from the
signal

and enables a resolution of all hyperfine transitions. We investigated the
resonance D2

line of rubidium vapour by External Cavity Diode Laser (ECDL). The observed
Dopplerbroadend

profiles consist of four lines, two of them resulting from 85Rb absorption and
the

other two from 87Rb. In SAS techique for each absorption line three hyperfine
transitions

and three belonging crossovers were obtained. In addition, we performed the
theoretical

simulations of the measured Lorentzian profiles. In saturation spectrum of 87Rb
an inverse

negative crossover resonance appiered as a consequence of alignment effect and
its

dependence on polarization of the laser beams and on the magnetic field strength
was

measured.

We measured line shape dependence on the magnetic field strength. Our
experimental

arrangement contains of two parts in order to measure magnetic field effect on
rubidium

vapour at one part and simultaneously compare it with the other one that has no
magnetic

field influence. In this way the first part serves as a reference scale for
frequency valuation.

An offset in the central frequency line position, increase in linewidth of each
transition

line and decrease in line intensity due to the enhancement of magnetic field
strength were

observed. Measured experimental results show good agreement with applied
theoretical

model.

Our experimental measurements belong to a group of nonlinear magneto-optic
effects

that show their significance in laser spectroscopy, where they are applied in
high-precision

magnetometry, weak transition researches such as magnetic dipole transition with
small

magnetic moment, parity violation experiments and nowadays in quantum computing

processing investigations.

[1] W. Demtroeder, Laser Spectroscopy, (Springer-Verlag, Berlin, 2003)

CP 94

116

Electric field influence on the hydrogen atom

embedded in a plasma

Mariusz Pawlak and Mirosław Bylicki

Institute of Physics, Nicolaus Copernicus University

Grudziadzka 5, PL-87-100 Torun, Poland

The energy levels of a hydrogen atom in a uniform strong electric field and
embedded

in a plasma are investigated. The plasma environment modifies the potential
around the

charged particle. This influence is represented by the Debye screening. Hence
the Yukawa

potential is used to represent the plasma-modified electron-nucleus interaction.
The effect

of this modification is that [1]: (i) The number of bound states of a given
spherical

symmetry (for a given orbital quantum number) is finite. (ii) Their energy
levels are

shifted up. (iii) The states whose energies are shifted just above the continuum
threshold

become resonances.

An external homogeneous electric field causes further changes: (iv) It breaks
down the

spherical symmetry. (v) It shifts the energy of some states down and up of other
ones (the

Stark effect). (vi) It also turns all the bound states into quasibound
resonances.

We include all these effects in our complex coordinate rotation calculation
within a basis

set of square integrable functions. The obtained complex energies give us
positions and

widths of the energy levels. They migrate in the complex plane when the field
strength

changes. Occasionally they tend to cross. Interesting avoided crossing
structures appear.

References

[1] M. Bylicki, A. Stachów, J. Karwowski, P. K. Mukherjee, Chem. Phys. 331, 346
(2007)

CP 95

117

Dynamic and Geometric Phases in the Stark-Zeeman

e ect of the hyper ne structure of one-electron atoms

B. Schnizer, Th.Heubrandtner, E. Rossl, M. Musso

Institut fur Theoretische Physik - Computationl Physics, TU Graz, Austria

Virtual Vehicle Competence Center, Graz, Austria

Philips Research Europe - Hamburg, Germany, Sector Medical Imaging Systems

Fachbereich Materialforschung und Physik, Universitat Salzburg, Austria

A theoretical investigation of the Stark-Zeeman e ect of the np 2P3=2 ne
structure levels

of atoms with one radiant electron and a core of closed shells with nuclear spin
I = 1

(6Li) or I = 3/2 (7Li, 23Na, 69Ga, 71Ga) predicted crossings and anticrossings.
These were

con rmed in an experiment. They could be predicted in the adiabatic
approximation from

the structure of the energy surfaces En(B;E) in their dependence on the magnetic
eld B

and the electric eld E. Two of these surfaces meet in the crossing points. There
are two

types of such crossing points resulting from the quadratic dependence of the
Stark e ect

on E. In some crossing points the energy surfaces meet in a bicone, in the other
ones

they have an osculating contact in the E-direction. When the electric and
magnetic elds

are varied such that the phase point of the atom surrounds a biconical crossing
points

then the wave functions of the two levels concerned change sign; on the other
hand a path

around a crossing point of the second type does not change the sign. We assume
that

the change in sign corresponds to a geometric phase of absolute value . As a rst
step

for the feasibility of nding this geometric phase in an experiment, the dynamic
phase

connected with such time-dependent eld variations has been investigated. Values
of all

these phases will be presented.

CP 96

118

New analytical relativistic formulae for the total

photoeŽect cross section for the K-shell electrons

A. Costescu1, C. Stoica1 S. Spanulescu2

1University of Bucharest

2Hyperion University of Bucharest

We present a new analytical relativistic result for the total photoeŽect cross
section for

the K-shell electrons, in the lowest order of perturbation theory. In the cases
of low atomic

number values, the well known Sauters formula is recovered as a rough
approximation of

the exact relativistic result. For high atomic numbers, due to the speci¯c
behavior at

small distances from the nucleus of the ground state Dirac spinor, some subtle
relativistic

eŽects are revealed near the photoeŽect threshold. Also, our formulae contain
all terms

contributing at high energies in the next order of the perturbation theory,
obtaining in

the limit of in¯nite photon energy the correction term due to Pratt and Gavrila.
In the

nonrelativistic limit, we get the right result involving all the multipoles and
retardation

terms without the spurious singularities presented by Fischer's formula.
Numerical eval-

uations of these formulae give very good predictions, within 5% for photon
energies up to

5 MeV, comparing with accurate relativistic calculations existing in the
literature.

Using the Green function method we obtain the imaginary part of the forward
elastic

scattering amplitude which provides via the optical theorem the photoeŽect cross
section

and also the pair production cross section with the electron created in the K
shell.

Our formalism allows including the screening eŽects which may be important near
the

photoeŽect threshold, by using an eŽective nuclear charge Zeff depending on the
pho-

ton energy !. Taking into account the screening eŽects, the obtained photoeŽect
cross

sections present an even better agreement with the experimental cross sections
and other

relativistic calculations in the region near the threshold.

We point out that cross section for the K -shell electrons provides, in the high
energy

regime, the most important contribution to the total cross section of the whole
atom.

Thus, our formulae are useful for an important range of the gamma spectrum,
where

there is a lack of accurate formulae for the photoeŽect cross sections, and may
present

interest in various experiments where gamma interactions with intermediate and
high Z

targets are involved.

References

[1] Lynn Kissel, R. H. Pratt, and S. C. Roy, Phys. Rev. A 22, 1970 (1980);

[2] J.H. Sco¯eld, Lawrence Radiation Laboratory Report No. CRL 51326, Livermore,
CA,

1973 (unpublished)

[3] L. Hostler, R.H. Pratt, Phys. Rev. Lett. 10, 469 (1963);

[4] C.Martin, R. J. Glauber,"Relativistic Theory of Radiation Orbital Electron
Capture",

Phys. Rev. 109, 1307 (1958);

[5] J. Schwinger, J. Math. Phys, 5, 1606 (1964);

[6] M. Gavrila, AIP Conf. Proc. No. 94,Eugene, Oregon, 1982.

CP 97

119

Two-photon above-threshold ionization by a

VUV-light

N. L. Manakov, S. I. Marmo and S. A. Sviridov

Department of Physics, Voronezh State University,

Voronezh, 394006, Russia

E-mail: sviridovs@yandex.ru

Recent experiments on two-photon above-threshold ionization (2ATI) of inert
gases [1,2]

by a VUV radiation renewed the interest to the perturbative analysis of 2ATI
(since in

VUV region the perturbation theory (PT) is valid up to high light intensities).
The main

difficulty of such calculations is the summation over the intermediate (after
absorption of

the first photon) continuum states of escaping electron. In the present work, we
calculate

the cross sections of 2ATI for He and alkali atoms in the single-active electron
approximation,

using the Fues model potential (FMP) for description of an active atomic
electron. The

known analytical expression for the Sturmian expansion of FMP Greens function
allows

to present the 2ATI amplitude in terms of a single series of hypergeometric
functions

of two variables, F2 (Appel functions) [3], that, however, becomes divergent for
abovethreshold

frequencies, ¯hω > |E0|, where E0 is the ground state energy. For summation of

this divergent series we use the Pade-approximation (ε-algorithm), similarly to
that used

for calculations of 2ATI for the hydrogen atom [4]. We justify the applicability
of the ε-

algorithm to our problem by independent calculations of the imaginary part of
the 2ATI

amplitude and by analytical calculations of low-frequency asymptotics in the in
two-color

2ATI (by two, high-frequency and low-frequency, photons). Our numerical results
are in

reasonable agreement with experiments [1,2] and other theoretical results
[5,6,7,8].

Supported in part by RFBR Grant 07-02-00574.

Table 1: Total cross-sections, σ (in units of 10−52 cm4s), of two-photon
ionization (in

linearly polarized field) of He and comparison with experiments and perturbative
and

non-perturbative theoretical results [5,6,7,8].

ω, eV Exp. [5] [6] [6], PT [7] [8] σFMP

15.0 11 12 12 13

25.0 1.9 [1] 1.0 3.2

27.2 1.0 4.5 2.5 2.7 2.2

41.8 2.0 [2] 0.53 0.35

45.0 0.12 1.0 0.33 0.26

References

[1] N. Miyamoto, M. Kamei, D. Yoshitomi et al., Phys. Rev. Lett. 93, 083903
(2004).

[2] H. Hasegawa, E.J. Takahashi, Y. Nabekawa et al., Phys. Rev. A 71, 023407
(2005).

[3] N.L. Manakov and V.D. Ovsiannikov, J. Phys. B 10, 569 (1978).

[4] S. Klarsfeld and A. Maquet, J. Phys. B 12, L553 (1979).

[5] L.A.A. Nikolopoulos and P. Lambropoulos, J. Phys. B 34, 545 (2001).

[6] J. Colgan and M.S. Pindzola, Phys. Rev. Lett. 88, 173002 (2002).

[7] D. Proulx and R. Shakeshaft, J. Phys. B 26, L7 (1993).

[8] K.L. Ishikawa, unpublished (cf. Ref. [2]).

CP 98

120

Above-threshold polarizability of alkali-metal and

noble gas atoms

N. L. Manakov, S. I. Marmo and S. A. Sviridov

Department of Physics, Voronezh State University,

Voronezh, 394006, Russia

E-mail: sviridovs@yandex.ru

We investigate the dynamic polarizabilities of atoms of alkali metals and inert
gases in the

framework of Fues model potential (FMP) method. Using FMP for the atomic valence

electron provides a simple one-particle method for calculation of atomic
photoprocesses

[1]. The convenient Coulomb-like expressions for the optical electrons
wavefunctions and

Green function for FMP enables easy calculations resulting in representations of
linear and

nonlinear atomic susceptibilities in terms of series in hypergeometric
polynomials. These

series can be easily summed at below-threshold frequency values (negative
energies of

intermediate states) that in most cases yields the atomic susceptibilities with
a reasonable

degree of accuracy. However, for the above-threshold frequencies (¯hω > |E0|)
the standard

use of FMP becomes impossible since it leads to divergent series.

For the calculation of the above-threshold boundbound transitions of optical
atomic

electron we develop in this work a special technique based on decomposition of
FMP

Green function g

l

(E; r, r

) into double series over Sturmian functions S

kl [2]:

g

l

(E; r, r

) =

∞

k,k

=0

gl

kk

(E; α) S

kl(2r/α) S

k

l(2r

/α) . (1)

Here S

kl(x) ∼ xλ exp (−x/2)L

2

λ

+1

k

(x), λ = λ(l,E), gl

kk

are expressed in terms of product

of Gauss hypergeometric functions 2F1 , α is the arbitrary parameter. To choose
the

value of the parameter α, an algorithm is given [3] which ensures the
convergence of the

boundbound matrix elements. Calculations of the above-threshold
polarizabilities are

performed for alkali metals and rare gases [3]. The obtained results agree well
with the

other authors calculations. In particular, the He polarizability in the 27...58
eV frequency

range coincides (within 10% accuracy) with more rigorous many-electron
calculation [4]

as well as with experiment [5].

Supported in part by RFBR Grant 07-02-00574.

References

[1] G. Simons, J. Chem. Phys. 55, 756 (1971).

[2] A.A. Krylovetsky, N.L. Manakov, and S.I. Marmo, Zh. Exp. Teor. Phys. 119, 45

(2001) [Sov. Phys. JETP 92, 37 (2001)].

[3] N.L. Manakov, S.I. Marmo, and S.A. Sviridov, Zh. Exp. Teor. Phys. 132, 796
(2007)

[Sov. Phys. JETP 105, 696 (2007)].

[4] W. C. Liu, Phys. Rev. A 56, 4938 (1997).

[5] J. A. R. Samson, Z. X. He, and G. N. Haddad, J. Phys. B 27, 877 (1994).

CP 99

121

Ionization in Intense Superposed XUV + NIR Laser

Fields

V. Richardson1, J. Dardis1, P. Hayden1, P. Hough1, E. T. Kennedy1 and J. T.
Costello1,

S. Dsterer2, W. Li2, A. Azima2, H. Redlin2, J. Feldhaus2, D. Cubaynes3, D.
Glijer3, M.

Meyer3,

1School of Physical Sciences, National Centre for Plasma Science and Technology,

Dublin City University, Dublin 9, Ireland

2HASYLAB, DESY, Notkestr. 85, D-22607 Hamburg, Germany

3LIXAM/ CNRS, UMR 8624 Centre Universitaire Paris-Sud, Btiment 350, F-91405

Orsay Cedex, France

FLASH (i.e. Free electron LASer in Hamburg) operates on the principle of Self
Ampli ed

Spontaneous Emission (SASE) and produces coherent, bright and ultrashort
eXtreme-

UV (XUV) pulses [1]. The current phase of the project has been in operation
since mid

2005. By synchronizing FLASH with an independent optical laser, so-called
'pump-probe'

experiments become possible [2,3]. These experiments are paving the way for
fundamental

studies of dynamical e ects in inner-shell photoionisation and
photodissociation, as well as

molecular fragmentation [4]. Apart from pump and probe experiments, it is also
possible

to induce and control coherent processes in superposed intense XUV and NIR elds.

One such process is photoelectron sideband generation [5]. In this class of
experiment,

photoelectrons are ejected by XUV radiation and simultaneously subjected to the
intense

eld of an optical laser with which they can exchange photons. In e ect, they
absorb/emit

photons with energy corresponding to h!l i.e. that energy of the optical laser
photons [3].

As a consequence the photoelectron spectrum is no longer comprised of a single
feature

corresponding to the main photoline but is straddled by additional photoelectron
lines

separated by h!l, these are referred to as sidebands. In our experiments at
FLASH we

have used the 800 nm output ( h!l = 1.55 eV) from a Ti-Sapphire laser which can
provide

pulses of up to a 10 mJ in pulse widths from 120 fs to 4 ps.

We have studied this process at high and low optical laser intensity for a range
of atoms,

namely He, Ne, Kr and Xe. In extreme cases we observe a large redistribution of
the

ejected electrons from the main photoline to the sidebands, so much so that a
pronounced

suppression of the main photoelectron line (corresponding to single XUV photon
absorp-

tion) occurs when the XUV and the optical pulses are perfectly superposed.

References

[1] W. Ackermann et al, Nature Photonics 1 336 (2007)

[2]P. Radcli e et al, App Phys Lett, 90, 121109 (2007)

[3]P. Radcli e et al, Nucl. Intr. and Meth. A (2007)

[4]J. T. Costello, J. Phys. Conf. Ser 88, (2007)

[5]T.E. Glover et al., Phys Rev Lett. 76, 2468 (1996)

CP 100

122

Photoionization of excited rare gas atoms

Rg(mp5(m+1)p J=0 { 3) in the

autoionization region

I. D. Petrov1, V. L. Sukhorukov1, and H. Hotop2

1Rostov State University of Transport Communications,

344038 Rostov-on-Don, Russia,

2Department of Physics, University of Kaiserslautern,

D-67653 Kaiserslautern, Germany

E-mail: hotop@physik.uni-kl.de

In the present paper we study theoretically the lineshapes of the even
autoionizing Ryd-

berg series mp5

1=2(m+1)`0 `0 = 0; 2; 4, excited from the lowest-lying odd mp5(m+1)p J =

0¡3 states of Ne, Ar, Kr, and Xe atoms in the framework of the con¯guration
interaction

Pauli-Fock approach including core polarization (CIPFCP) [1{3]. In our previous
work

[4{6] this approximation has successfully been applied for the investigation of
the odd

Rydberg resonances excited from the even states in rare gas atoms.

Autoionizing mp5

1=2(m + 1)`0 [K0]J0 Rydberg states, excited from diŽerent mp5(m +

1)p [K]J levels, attain diŽerent lineshapes, as usually characterized by the
pro¯le pa-

rameter q [7]. This dependence on the initial level was ¯rst demonstrated
experimentally

for the Ne(ns0; J = 1) resonances , excited from several Ne(3p, J = 1; 2) levels
[8]. The

comparison between the computed spectra and experimental data indicates that
many-

electron eŽects play an important role for both the resonance parameters and the
line-

shapes. Absolute values of the experimental cross sections, available for
photoionization

of the mp5(m+ 1)p J = 3 levels of Ne, Ar, and Kr, are somewhat smaller than the
com-

puted values. These diŽerences ask for new precise measurements, e.g. using cold
trapped

metastable Rg(mp5(m + 1)s [3=2]2) atoms, especially in view of the good
agreement be-

tween the theoretical and experimental cross sections for near-threshold
photoionization

of the mp6(m + 1)p levels in the alkali atoms Na { Cs [2,9,10].

Support of this work by the Deutsche Forschungsgemeinschaft is gratefully
acknowledged.

References

[1] I. D. Petrov, V. L. Sukhorukov, and H. Hotop J. Phys. B 32, 973 (1999).

[2] I. D. Petrov et al Eur. Phys. J. D 10, 53 (2000).

[3] I. D. Petrov, V. L. Sukhorukov, and H. Hotop, J. Phys. B 36, 119 (2003).

[4] T. Peters et al J. Phys. B 38, S51 (2005).

[5] I. D. Petrov et al Eur. Phys. J. D 40, 181 (2006).

[6] I. D. Petrov et al J. Phys. B 39, 3159 (2006).

[7] U. Fano and J. W. Cooper, Phys. Rev. 137, A1364 (1965).

[8] J. Ganz, M. Raab, H. Hotop, and J. Geiger, Phys. Rev. Lett. 53, 1547 (1984).

[9] K. Miculis and W. Meyer, J. Phys. B 38, 2097 (2005)

[10] I. D. Petrov, V. L. Sukhorukov, and H. Hotop, J. Phys. B 41, 065205 (11pp)
(2008).

CP 101

123

Spin Dependent Exchange Scattering from

Ferromagnetic Materials

S.Y. Yousif Al-Mulla

University of Bor as, College of Engineering, Physics and Mathematics
Group,50190

Bor as, Sweden

It is well known that the structure information through the use of Spin
Polarised Low

Energy Electron Di raction (SPLEED) is highly sensitive to the interaction
potential be-

tween the primary electrons and the electrons of the target, especially to the
exchange

interaction. Since the electrons in SPLEED penetrate the surface only a few
lattice spac-

ing, it is extremely sensitive to the spin structure of a magnetic surface. The
early study

of Feder [1] on Fe(110) provides a strong indication in this direction. The main
objective

of this work is to use the insights of our recent work [2,3] to study the spin
polarisation of

electron scattering from ferromagnetic materials by using the local density
approximations

of the exchange-correlation potential. The di erential cross sections for
electron scatter-

ing from atoms with net spin, namely nickel and iron, have been calculated
together with

studying the energy/ wave vector dependence of the exchange scattering from
surfaces

of nickel and iron in glasses by calculating di erential cross sections and the
spin asym-

metry. Comparison of predictions with observed spin dependent scattering
intensities in

amorphous magnetic alloys will give insight into surface magnetisation in these
systems.

[1] Feder R., Solid State Comm. 31, 821 (1979)

[2] S.Y. Yousif Al-Mulla, J. Phys. B: At. Mol. Opt. Phys. 37, 305 (2004)

[3] S.Y. Yousif Al-Mulla, Eur. Phys. J. D 42, 11 (2007)

CP 102

124

Far-wing collisionnal broadening of the Na(3s-3p)

line by helium

K. Alioua1, M. Bouledroua1, A. Allouche2, and M. Aubert-Frśecon2

1Laboratoire de Physique des Rayonnements, Badji Mokhtar University,

B.P. 12, Annaba 23000, Algeria

2LASIM, Claude Bernard University, Lyon 1, France

In this work, we examine theoretically the absorption spectra produced by sodium
atoms

immersed in a bath of helium. We present our classical and quantum-mechanical
cal-

culations of the photoabsorption spectra of the Na(3s!3p) line perturbed by
ground

He(1s2) atoms. We particularly focus our attention on the ab initio computation
with

molpro of the ground and excited potential-energy curves, through which the
systems

Na(3s)+Na(3s) and Na(3p)+Na(3s) interact, and of the corresponding transition
dipole

moments. These potentials and moments are used to analyze the absorption spectra
and

their possible satellite structure at various temperatures. The results are
compared with

previous theoretical and experimental data [1, 2].

References

[1] C. Zhu, J.F. Babb, and A. Dalgarno, Phys. Rev. A 73, 012506 (2006).

[2] H.-K. Chung, M. Shurgalin, and J.F. Babb, AIP Conference Proceedings 645,
211

(2002).

CP 103

125

Excited and ground potassium monatoms perturbed

by helium

S. Chelli and M. Bouledroua

Laboratoire de Physique des Rayonnements, Badji Mokhtar University,

B.P. 12, Annaba 23000, Algeria

The purpose of this work is to calculate quantum-mechanically the diŽusion
coeącients

of atomic potassium in helium as well as the width and shift of the K(4p ! 4s)
resonance

line perturbed by He. The diŽusion coeącients of ground K(4s) and excited K(4p)
in a

helium buŽer gas are analyzed and the results are compared for few temperatures
with

experimental and other theoretical data. Further, the pressure broadening
parameters are

treated by using the most recent interatomic potentials, spin-orbit eŽects
neglected. The

simpli¯ed Baranger method is particularly used to examine the linewidth and
lineshift

coeącients and their behavior with temperature.

CP 104

126

Pressure broadening of calcium resonance line

perturbed by helium

L. Reggami and M. Bouledroua

Laboratoire de Physique des Rayonnements, Badji Mokhtar University,

B.P. 12, Annaba 23000, Algeria

The aim of this work is to calculate quantum mechanically the width w and shift
d of

the neutral calcium lines Ca(4s2 1S) ¡! Ca(4s4p 1P) and Ca(4s2 1S) ¡! Ca (4s4p

3P) perturbed by helium He. The ab initio data points from Paul-Kwiek [1] are
used to

construct the potential-energy curves. For the ground state, X1§+, and the four
excited

states, 1§+, 1Ś, 3§+, and 3Ś, the potential data are smoothly connected to the
appropriate

long and short forms. The numerical integration of the radial wave equation
provides the

elastic phase shifts which allow the computation of the linewidth and lineshift
parameters

by adopting the pressure broadening simpli¯ed Baranger model [2]. The results
show

there is in general a good agreement with other experimental and theoretical
data [3, 4].

References

[1] E. Paul-Kwiek, private communication (2007).

[2] M. Baranger, Phys. Rev. 111, 481 (1958).

[3] A.R. Malvern, J. Phys. B 10, 593 (1977).

[4] J. RÄohe-Hansen and V. Helbig, J. Phys. B 25, 71 (1992).

CP 105

127

Broadening and intensity redistribution in the

atomic hyper¯ne excitation spectra due to optical

pumping in the weak excitation limit

E. Saks1, I. Sydoryk1, N. N. Bezuglov1;2, I. I. Beterov3 , K. Miculis1, and A.
Ekers1

1 Laser Centre, University of Latvia, LV-1002 Riga, LATVIA

2 Faculty of Physics, St.Petersburg State University, 198904 St. Petersburg,
RUSSIA

3 Institute of Semiconductor Physics SB RAS, 630090, Novosibirsk, RUSSIA

We analyze spectral line broadening and variations in relative intensities of
hyper¯ne

spectral components due to optical pumping at exciting laser intensities below
the satu-

ration limit. The study was motivated by by the lack of availability of detailed
theoretical

models describing such eŽects in partially open level systems. In experiment,
the hyper-

¯ne laser-excitation spectra of the Na(3p) state were measured in a supersonic
beam as

a function of laser intensity under the conditions when optical pumping time is
shorter

than transit time of atoms through the laser beam. The theoretical excitation
spectra

were calculated numerically by solving density matrix equations of motion using
the split

propagation technique [1; 2].

The following results will be reported: (i) it will be shown that spectral lines
can be

signi¯cantly broadened at laser intensities well below the saturation intensity,
which is

usually regarded as the threshold for onset of broadening eŽects; (ii) it will
be shown that

the presence of dark mF sublevels can vary the eŽective branching coeącients of
the tran-

sitions, and this variation depends on laser intensity. Changes in the eŽective
branching

coeącients lead to irregular changes of peak ratios, like minimum in the
intensity de-

pendence of the peak ratio, which deviate from those expected from the given
original

branching coeącients; (iii) analytical expressions will be presented, which
allow the cal-

culation of critical values for laser intensity and Rabi frequency, above which
linewidths

and peak ratios are notably aŽected by optical pumping. The critical laser
intensity can

be expressed via the saturation intensity Isat, the branching coeącient Ś of the
transition,

and the ratio of natural lifetime and transit time of atoms through the laser
beam ¿nat=¿tr:

Icr =

8¼2¹hc

p

¼3¸3

1

¿trŚ(1 ¡ Ś)

=

4¿nat p

¼¿tr (1 ¡ Ś)

Isat : (1)

Importantly, the critical laser intensity depends on the branching coeącient Ś
and has a

a minimum at Ś = 1=2, and it can be much smaller than the saturation intensity.

We acknowledge support by EU FP6 TOK Project LAMOL, Latvian Science Council,

and European Social Fund.

References

[1] M. D. Fiet, J. A. Fleck, and A. Steiger, J. Comput. Phys. 47, 412 (1982)

[2] I. Sydoryk, N. N. Bezuglov, I. I. Beterov, K. Miculis, E. Saks, A. Janovs,
P. Spels, and

A. Ekers, Phys. Rev. A (2008) in print

CP 106

128

Reconsideration of spectral line pro¯les aŽected by

transit time broadening

B. Mahrov1, C. Andreeva1;2, N. N. Bezuglov1;3, K. Miculis1, E. Saks1, M.
Bruvelis1, and

A. Ekers1

1 Laser Centre, University of Latvia, LV-1002 Riga, LATVIA

2Institute of Electronics, Bulgarian Academy of Sciences, So¯a 1784, Bulgaria

3 Faculty of Physics, St.Petersburg State University, 198904 St. Petersburg,
RUSSIA

In the weak excitation limit in dilute gases, when saturation and collision
eŽects are

negligible, line broadening occurs due to spontaneous decay (width ¡sp), Doppler
eŽect,

and, if atoms interact with tightly focused cw laser beams, also due to limited
transit time

¿tr of atoms through the laser beam. Consider a two step excitation process, in
which

Doppler broadening is avoided using counterpropagating laser ¯elds. The
conventional

knowledge says that the the resultant lineshapes are given by the Lorenz pro¯le
[1]

P(¢) = ¼e¡=

³

¢2 + e¡2

´

; 2¢! = e¡ = ¡sp + 1=¿tr; (1)

where ¢ is the detuning of the laser ¯elds oŽ from the two-photon resonance, and
2¢!

is the FWHM width. If an atom from a supersonic beam at a °ow velocity vf
crosses a

Gaussian laser beam of FWHM L, then it is reasonable to assume ¿tr = L=vf .

We consider excitation of the Na(5S1=2) HF sublevel F = 2 with lifetime ¿sp =
76ns

by two counter-propagating laser beams, which models an eŽective two-level
quantum

system. Laser in the ¯rst step is focused to L1 = 30¹m using a cylindrical lens
and

detuned by ¢º1=100MHz oŽ from resonance with the 3S1=2; F00 = 1 ! 3p1=2; F0 =

2 transition. The second laser is collimated to L2 = 1000¹m, while its frequency
is

scanned across the two-photon resonance. The detuning ¢º1 is suącient to ensure
that

the intermediate level is virtual. Both lasers cross the atomic beam with °ow
velocity of

vf = 1200m/s at right angles. The time dependence of their Rabi frequencies are
given

by i(t) = (i)

0 exp(¡2t2=¿2

i;tr), which corresponds to a Gaussian laser intensity pro¯les

Ii(z) = I(i)

0 exp(¡4z2=L2

i ) along the atomic beam axis z. The spatial distribution of the

corresponding eŽective Rabi frequency is given by eff (z) = 1(z)2(z)=¢!1.

We have obtained analytical solutions to this model porlem which show that the
lineshape

of excitation of the upper state is described by the Voight pro¯le with FWHM
which can

be approximated (within the accuracy level of 10%) by the expression

2¢!res =

q

¡2

sp + 19:2 ¢ ln(2)=¿2

tran: (2)

Importantly, the value of the width 2¢!res exceeds the intuitive one 2¢! (1) by
a factor

of four if the broadening occurs predominantly due to limited transit time, i.e.
when

¿tran < 1=¡sp = ¿sp.

We acknowledge support by EU FP6 TOK Project LAMOL (Contract MTKD-CT-2004-

014228), Latvian Science Council, European Social Fund.

References

[1] B.W.Shore, The Theory of Coherent Atomic Excitation (Wiley, New York, 1990).

CP 107

129

Alkali doped Helium Droplets in a Magnetic Field

G. AubÄock, J. Nagl, C. Callegari, W.E. Ernst

Institute of Experimental Physics, Graz University of Technology, Austria

Helium nanodroplets are produced by supersonic free jet expansion and provide a
cold

environment (T ¼ 0.4 K) for dopant atoms and molecules. Helium droplets can
dissipate

energy very eąciently by evaporating some of their own atoms. Alkali atoms are
de-

posited onto the droplet by passing the droplet beam through one or more heated
pick-up

cells containing alkali vapor. Capture of multiple atoms per droplet leads to
molecular

formation; alkali-metal species are unique dopants in that they remain on the
droplet's

surface. Most degrees of freedom of dopant atoms and molecules are immediately
cooled

to the droplet's internal temperature and the energy released leads to further
evaporation

of helium atoms. This applies in particular to the energy of formation of
complexes, which

may be large enough to cause them to be expelled from the droplet: due to their
smaller

binding energy it is the high spin alkali complexes (triplet dimers, quartet
trimers) which

preferentially remain on the droplet after formation.

High-spin molecules are very interesting systems, and relate to a variety of
topics such as

Bose-Einstein condensation, molecule formation by photoassociation or magnetic
tuning,

many-body forces, reactivity and magnetism of small metal clusters, the
Jahn-Teller eŽect,

electron- and nuclear-spin resonance.

Here we summarize several results of our investigations of alkali doped He
droplets in a

magnetic ¯eld. This series of experiments was initially started to investigate
the feasibility

of optical preparation and detection of spin states for further electron spin
resonance

experiments. For atom doped droplets (K and Rb) we found that the spin state
does

not thermalize with the He droplet on the time scale of our experiment (we can
extract

a relaxation rate <1000/s). Usually alkali atoms (molecules) are evaporated from
the

droplet surface upon electronic excitation what can be used for the preparation
of a spin

polarized beam by spin selective optical depletion for K. Contrary to common
wisdom,

we found that nondestructive excitation is possible at the Rb D1 line, this
makes optical

pumping feasible.

Unlike atoms, the spin state fully thermalizes with the internal temperature of
the droplet

for dimers and trimers. Then the population diŽerence of the ground state Zeeman

sublevels causes the appearance of a C-type magnetic circular dichroism (MCD).
In fact

the amplitude of the MCD signal can be used to determine the temperature on the
droplet

surface which is a priori not necessarily equal to the temperature measured in
the interior.

For dimers, the MCD spectrum further allowed us to interpret consistently the
structure

of (1)3Śg - (a)3§+

u transitions for several molecules (K2, Rb2, Cs2, KRb, LiCs, NaCs) as

an interplay of a perturbation of the excited state electronic wave function by
the droplet

surface and spin orbit coupling. For trimers we investigated the LIF and MCD
spectra

of the (2)4E0 - (1)4A0

2 transition of K3 and Rb3. We interpret these spectra as eE

vibronic coupling plus spin-orbit coupling. This is to our knowledge the ¯rst
observation

of relativistic vibronic coupling in a quartet states.

CP 108

130

Quartet alkali trimers on He nanodroplets: Laser

spectroscopy and ab initio calculations

J. Nagl, G. Aub¨ock, A. W. Hauser, O. Allard, C. Callegari, and W. E. Ernst

Institute of Experimental Physics, Graz University of Technology, Graz, Austria

Helium nanodroplets (N = 104) are produced by supersonic free jet expansion and
provide

a cold environment (T = 0.4 K) for dopants; the droplets can dissipate energy
very

efficiently by evaporating their own atoms (binding energy per He atom: 5 cm−1).
Alkali

atoms are deposited on the helium surface by passing the droplet beam through
one

or more heated pick-up cells containing alkali vapor. Capture of multiple atoms
per

cluster leads to molecular formation. Due to the amount of binding energy
released

into the cluster, in general a strongly bound low-spin molecule will be expelled
from

the droplet beam, while a weakly bound high-spin van der Waals molecule will
not. A

variety of electronic spectra of the homo- and heteronuclear trimers K3, Rb3,
K2Rb and

KRb2 in their high-spin quartet state lie in the wavelength range 1050017500
cm−1. We

measured them and applied various schemes of beam depletion spectroscopy, such
as twolaser

excitation and mass-selective depletion to separate overlapping spectral
features,

and to assign the individual bands.

We find several regular patterns in the spectra of these trimers, which we are
in the

process of explaining by means of symmetry arguments and simplified models of
their

level structure. The experiments are supported by high-level ab-initio
electronic structure

calculations.

References

[1] Johann Nagl, Gerald Aub¨ock, Andreas W. Hauser, Olivier Allard, Carlo
Callegari,

and Wolfgang E. Ernst. Heteronuclear and homonuclear high-spin alkali trimers on

helium nanodroplets. Phys. Rev. Lett. 100, 063001 (2008).

[2] Johann Nagl, Gerald Aub¨ock, Andreas W. Hauser, Olivier Allard, Carlo
Callegari,

and Wolfgang E. Ernst. High-spin alkali trimers on helium nanodroplets: Spectral

separation and analysis. J. Chem. Phys. 128, 154320 (2008).

CP 109

131

Group Dynamics of 2-Atom Even-Electron Molecules

and Ions

R. Hefferlin

Physics Department, Southern Adventist University

Collegedale, Tennessee 37315, United States of America

E-mail: hefferln@southern.edu

The group SO(3) is used to characterize even-electron atoms on the basis of
their electron

counts. The atoms are arranged in multiplets that have chemical angular
momentum

quantum numbers l and z-component m

l [1-3]. Atoms in group 2 have (l,m

l) = (0,0);

atoms in groups 14, 16, and 18 have l = 1 and m

l = -1, 0, +1. Negatively-charged atoms

of groups 1, 13, 15, and 17 have the same quantum numbers; unipositive ions of
atoms in

groups 3, 15, 17, and (from the next higher period number) 1 also have the same
quantum

numbers; more highly-ionized species follow the same pattern.

Odd-electron atoms may be characterized in the very same way. Neutral atoms in
group

1 have (l,m

l) = (0,0); atoms in groups 13, 15, and 17 have l = 1 and m

l = -1, 0, +1.

Their ions follow the same pattern. Likewise, transition-metal and rare-earth
atoms are

arranged in multiplets with l = 2 and 3. (The period numbers are not defined in
the

algebra and may be chosen at will.)

Atoms or ions are now defined as vectors in the space H(1). The bosonic raising
operator

of SO(3) [4,5] is used to combine two even-electron multiplets, or two
odd-electron

multiplets, of atoms or ions to form multiplets of even-electron vectors in the
space H(2)

of diatomic molecules and ions. These multiplets are then combined, using an
empirical

function of the two period numbers, to construct the group-dynamic periodic
system

of the even-electron gas-phase diatomic species. Some forecasted data for
spectroscopic

properties of the species are presented.

References

[1] Y.B. Rumer, A.I. Fet, Teor. Mat. Fiz. (Russ.) 9, 203 (1971)

[2] A.I. Fet, Theor. Math. Phys. 22, 227 (1975)

[3] A.O. Barut, Group Structure of the Periodic System, in B. Wybourne, Ed.,
Structure

of matter (Proceedings of the Rutherford Centennary Symposium, 1971): University
of

Canterbury Press, Canterbury, 1972, pp. 126-136.

[4] G.V. Zhuvikin, R. Hefferlin, The Periodic system of Diatomic Molecules:
Group-

Theoretical Approach, Vestnik Leningradskovo Universiteta, No. 16, 1983, pp.
10-16.

[5] G.V. Zhuvikin, R. Hefferlin, Joint Report #1 of the Physics Departments of
Southern

College [SAU], Collegedale, TN, USA and St. Petersburg University, St.
Petersburg,

Russia, Southern Adventist University: Collegedale, Tennessee, 1994.

CP 110

132

Cavity-QED with ion Coulomb crystals

A. Dantan, P. Herskind, J. Marler, M. Albert, M.B. Langkilde-Lauesen, M. Drewsen

QUANTOP, Department of Physics and Astronomy, University of Aarhus,

Ny Munkegade, bygning 1520, D8000 Aarhus, Denmark

In addition to its fundamental interest for atom-light studies, Cavity Quantum
Electro-

dynamics (CQED) represents an interesting avenue for engineering eącient
light-matter

quantum interfaces for quantum information processing. Experiments with neutral
atoms

have been very successful in strongly coupling single atoms to cavities of
extremely small

mode volume and very high ¯nesse. However, these experiments are challenged by
the

diąculty in con¯ning and storing the atoms in the cavity for a long time [1].

Ions, on the other hand, have proved to be an excellent medium for quantum
information

processing and bene¯t from very long trapping times, a good localization and are
robust

against decoherence. However, minimizing the mirror separation, without severely
modi-

fying the trapping potential has made it extremely diącult to reach the strong
coupling

regime with a single ion [2,3]. The small mode volume requirement can be relaxed
for en-

sembles of atoms or ions due to the enhancement of the collective coupling
strength of the

ensemble. In addition to tight con¯nement and long storage times, ion Coulomb
crystals

also have a number of advantages over cold atomic samples. As the ions are
con¯ned in

a crystal lattice, the decoherence rate due to collisions is very low and their
low optical

densities (108cm¡3) make optical pumping and state preparation unproblematic.
Finally,

the inherent lattice structure in conjunction with the standing wave ¯eld of the
optical

resonator opens up for new possibilities to engineer the atom-photon
interaction.

We will present recent experimental results on CQED with cold ion Coulomb
crystals of

calcium, obtained by using a novel linear ion trap incorporating a moderately
high ¯nesse

cavity (F ť 3200). Even though the 3-mm diameter dielectric cavity mirrors are
placed

between the trap electrodes and separated by only 12 mm, it is possible to
produce in situ

ion Coulomb crystals containing more than 105 calcium ions of various isotopes
and with

lengths of up to several millimetres along the cavity axis [4]. Single to a few
thousands of

ions can be stored in the cavity mode volume and eąciently prepared by optical
pumping

in a given magnetic substate of the metastable 4d2D3=2 level of 40Ca+. The ¯rst
results

on the crystal-light coupling strength - evaluated by probing the ion-cavity
system at the

single photon level - and the possibilities for CQED oŽered by this new system
will be

discussed.

[1] P.R. Berman (Ed.) Cavity Quantum Electrodynamics, Academic Press inc.,
London

(1994)

[2] M. Keller, B. Lange, K. Hayasaka, W. Lange, H. Walther, Nature 431, 1075
(2004)

[3] A.B. Mundt, A. Kreuter, C. Russo, C. Becher, D. Leibfried, J. Eschner, F.
Schmidt-

Kaler, R. Blatt, Appl. Phys. B 76, 117 (2003)

[4] P. Herskind, A. Dantan, M.B. Langkilde-Lauesen, A. Mortensen, J. L.
S¿rensen, M.

Drewsen, quant-ph/0804.4589.

CP 111

133

Spin flip lifetimes in superconducting atom chips

Ulrich Hohenester1, Asier Eiguren2, Stefan Scheel3, and E. A. Hinds3

1Institut f¨ur Physik, KarlFranzensUniversit¨at Graz, Austria

2Donostia International Physics Center (DIPC), San Sebastian, Spain

3Quantum Optics and Laser Science, Imperial College London, United Kingdom

Over the last few years, enormous progress has been made in magnetic trapping of
ultracold

neutral atoms near microstructured solid-state surfaces, sometimes known as atom

chips [1]. The atoms can be manipulated through variation of the magnetic
confinement

potential, either by changing currents through gate wires mounted on the chip or
by

modifying the strength of additional radio-frequency control fields. These
external, timedependent

parameters thus provide a versatile method of atom manipulation, and make

atom chips attractive for various applications, including atom interferometry,
quantum

gates and coherent atom transport.

The proximity of the ultracold atoms to the solid-state structure introduces
additional

decoherence channels, which limit the performance of the atoms. Most
importantly,

Johnson-Nyquist noise currents in the dielectric or metallic surface
arrangements produce

magnetic-field fluctuations at the positions of the atoms. Upon undergoing
spin-flip

transitions, the atoms become more weakly trapped or are even lost from the
microtrap.

This constitutes a serious limitation for atom chips. Superconductors could
reduce the

magnetic noise level significantly and thereby boost the spin flip lifetimes by
many orders

of magnitude. Indeed, superconducting atom chips have already been fabricated
and

tested [2, 3] with the aim of realizing controllable composite quantum systems.

In this contribition we investigate theoretically the magnetic spin-flip
transitions of neutral

atoms trapped near a superconducting slab [4, 5]. We find that below the
superconducting

transition temperature the spin-flip lifetime becomes boosted by several orders

of magnitude, a remarkable finding which is attributed to: (1) the opening of
the superconducting

gap and the resulting inability to deposit energy into the superconductor,

(2) the highly efficient screening properties of superconductors, and (3) the
small active

volume within which current fluctuations can contribute to field fluctuations.
Our numerical

results based on the Eliashberg theory show that the expected spin-flip lifetime

for an atom placed one micrometer away from a 4.2 K superconducting planar
niobium

surface exceeds several thousand seconds. Hence, superconducting surfaces
provide an

extremely low-noise environment for magnetically trapped neutral atoms and thus
have

great potential for coherent manipulation of atoms.

References

[1] J. Fortagh and C. Zimmermann, Rev. Mod. Phys. 79, 235 (2007)

[2] T. Nirrengarten, A. Qarry, C. Roux, A. Emmert, G. Nogues, M. Brune, J. M.
Raimond,

and S. Haroche, Phys. Rev. Lett. 97, 200405 (2006)

[3] C. Roux, A. Emmert, A. Lupascu, T. Nirrengarten, G. Nogues, M. Brune, J.-M.

Raimond, and S. Haroche, Euro. Phys. Lett. 81, 56004 (2008)

[4] B. S. Skagerstam, U. Hohenester, A. Eiguren and P. K. Rekdal, Phys. Rev.
Lett. 97,

070401 (2006)

[5] U. Hohenester, A. Eiguren, S. Scheel, and E. A. Hinds, Phys. Rev. A 76,
033618

(2007)

CP 112

134

Interaction-Free Measurement of the Degree of

Polarization of an Atomic Ensemble

Alessandro Cer e;1 Valentina Parigi;2 Marta Abad;1 Florian Wolfgramm;1

Ana Predojevic1 and Morgan W. Mitchell1

1ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park,
Castelldefels,

08860 Barcelona, Spain

2LENS, Via Nello Carrara 1, 50019 Sesto Fiorentino, Florence, Italy

In the last years, several proposals for quantum information and quantum
communication

schemes require the use of atomic media together with single photons. Among the
possible

interactions, much interest has been generated by non destructive techniques,
like the

quantum non-demolition measurement. We present here instead a characterization
of the

polarization state of an atomic sample via the non-interaction of our sample
with the

probe, thus reducing, in principle, the damage to the sample for successful
event to zero.

The term \interaction-free" applies to a measurement process where the probe
carries

information about a system without interacting with it, possible thanks to the
quantum

nature of the interference process. After the proposal of Elitzur and Vaidman
[1], an

experimental demonstration was provided by Kwiat et al. [2]. We have realized an
inter-

action free measurement of the spectrum and polarization state of a hot ensemble
of 87Rb

by inserting it in a polarization interferometer, where a di erent optical
density for one of

the polarization modes is revealed by detection of light at the output dark in
the balanced

case The probe is a narrowband coherent light, strongly attenuated to the single
photon

level, with a central frequency that can be scanned by some GHz in the region of
the Rb

D1 line. The atoms are optically pumped by an intense beam into the mF =1,2
Zeeman

substates of the F=2 hyper ne level. Observing the output of the dark port while
scan-

ning the probe frequency, the obtained trace presents a peak in correspondence
with the

transitions involving the hyper ne ground level F=2. The pro le of the trace
corresponds

to the pro le of the transition, power broadened by the intense pumping
necessary for

polarization.

The demonstrated scheme su ers from limited statistical e ciency, equal to 1/4
in theory

and further reduced because of experimental imperfections. It has been
demonstrated

that combining the interaction free measurement approach and an implementation
of

the quantum Zeno e ect it is possible reach a theoretical e ciency close to
unity [3].

Moreover, this scheme could be used to measure the degree of polarization of a
sample of

atoms reducing the damage compared with standard absorption techniques [4].

References

[1] A. Elitzur and L. Vaidman, Foundations of Physics 23, 987 (1993).

[2] P. G. Kwiat et al., Phys. Rev. Lett. 74, 4763 (1995).

[3] P. G. Kwiat et al., Phys. Rev. Lett. 83, 4725 (1999).

[4] P. Facchi et al., Phys. Rev. A 66, 012110 (2002).

CP 113

135

Entangled atom-pairs from dissociated dimers:

an experimental test of Bell inequality for atoms

J. Koperski1, M. Kro´snicki2, and M. Strojecki1

1Smoluchowski Institute of Physics, Jagiellonian University

Reymonta 4, 30-059 Krakow, Poland

2Institute of Theoretical Physics and Astrophysics

University of Gdansk, Wita Stwosza 57, 80-952 Gdansk, Poland

E-mail: ufkopers@cyf-kr.edu.pl

In 1964 Bell showed that in all local realistic theories, correlations between
the outcomes

of measurements in different parts of a physical system satisfy certain class of
inequalities

[1]. Furthermore, he found that certain predictions of quantum mechanics violate
these

inequalities. Starting with the first experimental tests of Bell inequalities
with photons

[2], violation of a Bell inequality has been observed for protons [3], K mesons
[4], ions [5],

neutrons [6], B mesons [7], atom-photon systems [8], and atomic ensembles [9].

Production of entangled atom-pairs via stimulated two-photon Raman dissociation
of

dimers produced in supersonic free-jet pulsed beam will be described. The
process re-

lies on the proposal of Fry et al. [10] for experimental realization of Bohms
spin-1/2

particle version of the Einstein-Podolsky-Rosen (EPR) experiment. The first
stage of

the experiment, designed for 199Hg atoms, is underway at Texas A&M University.
The

real challenge is to isolate a particular rotational transition within a
triplet-singlet D31u

X110+

g

electronic transition in 199Hg2 propagating in the beam [11], and then
dissociate

the excited isotopomer using a stimulated Raman process. Pairs of entangled
199Hg atoms

obtained in this way are going to be spin-state-selectively detected in two
different atom

detectors located in two parallel planes of detection.

An alternative approach is to selectively dissociate 111Cd2 isotopomers produced
in a

continuous supersonic free-jet using selected rotational transition within a
singlet-singlet

A10+

u

X10+

g

electronic transition in 111Cd2. During the conference the advantages of using

the latter approach and recent developments in the endeavor of testing Bell
inequality for

111Cd atoms planned in Krakow will be reported.

This work was financed from 2007-2010 funds for science of Polish Ministry of
Science

and Higher Education (research project N N202 2137 33).

References

[1] J.S. Bell, Physics (Long Island City, N.Y.) 1, 195-200 (1964).

[2] S.J. Freedman, J.F. Clauser, Phys. Rev. Lett. 28, 938-941 (1972).

[3] M. Lamehi-Rachti, W. Mittig, Phys. Rev. D14, 2543-2555 (1976).

[4] A. Bramon, M. Nowakowski, Phys. Rev. Lett. 83, 1-5 (1999).

[5] M.A. Rowe et al., Nature (London) 409, 791-794 (2001).

[6] Y. Hasegawa et al., Nature (London) 425, 45-48 (2003).

[7] A. Go, J. Mod. Opt. 51, 991-998 (2004).

[8] D. L. Moehring et al., Phys. Rev. Lett. 93, 090410 (2004).

[9] D. N. Matsukevich et al., Phys. Rev. Lett. 96, 030405 (2006).

[10] E. Fry, T. Walther, S. Li, Phys. Rev. A 52, 4381-4395 (1995).

[11] J. Koperski et al., Chem. Phys. (2008), in press.

CP 114

136

Primary gas thermometry by means of near-infrared

laser absorption spectroscopy and determination of

the Boltzmann constant

G. Casa1, A. Castrillo1, G. Galzerano2, R. Wehr1, A. Merlone3, D. Di Sera¯no4,
P.

Laporta2 and L. Gianfrani1;y

1Dipartimento di Scienze Ambientali, Seconda Universitľa di Napoli, Caserta,
Italy

2Dipartimento di Fisica, Politecnico di Milano and Istituto di Fotonica e
Nanotecnologie

(IFN-CNR), Milano, Italy

3 Istituto Nazionale di Ricerca Metrologica, Torino, Italy

4Dipartimento di Matematica, Seconda Universitľa di Napoli, Caserta, Italy

ylivio.gianfrani@unina2.it

We report on a new method for primary gas thermometry, based on high-precision,

intensity-stabilized laser absorption spectroscopy in the near-infrared.
Initially designed

and developed for the accurate determinations of absolute linestrength factors
[1], the

method consists in retrieving the Doppler width from the absorption line shape
corre-

sponding to a given vibration-rotation transition in a CO2 gaseous sample at
thermo-

dynamic equilibrium. There is presently a strong interest in new primary
thermometric

methods, likely to be employed for direct and highly accurate determinations of
the Boltz-

mann constant kB, in view of a possible new de¯nition of the unit kelvin [2].

We probed the R(12) component of the º1+2º 0

2 +º3 combination band, using a distributed

feedback diode laser, which was mounted in a mirror-extended cavity
con¯guration. Con-

sisting of a cylindrical cavity inside an aluminum block, with inner and
external surfaces

carefully polished, the absorption cell was housed inside a stainless steel
vacuum chamber

and its temperature was stabilized at a level of ť10 mK by means of an active
system

based on four Peltier elements and a PID controller. The gas temperature was
measured

by means of precision platinum resistance thermometers, carefully calibrated at
the triple

point of water and at the gallium melting point with an overall accuracy better
than 10

mK. By doing Doppler broadening measurements as a function of the gas
temperature,

which was varied between 270 and 305 K, we determined the Boltzmann constant
with

an uncertainty of 1:6 £ 10¡4, including statistical and systematic errors [3].

We also report on the status of a second-generation experiment, in which a pair
of phase-

locked extended-cavity diode lasers are being employed in order to improve
signi¯cantly

the capability of measuring laser frequency variations.

References

[1] G. Casa, D. A. Parretta, A. Castrillo, R. Wehr, and L. Gianfrani, J. Chem.
Phys.

127, 084311 (2007)

[2] B. Fellmuth et al., Meas. Sci. Technol. 17, R145 (2006)

[3] G. Casa, A. Castrillo, G. Galzerano, R. Wehr, A. Merlone, D. Di Sera¯no, P.
Laporta

and L. Gianfrani, Phys. Rev. Letters, in press

CP 115

137

Towards precision spectroscopy in the XUV

Valentin Batteiger1, Maximilian Herrmann1, Sebastian Knunz1, Akira Ozawa1,
Andreas

Vernaleken1, Guido Saatho 1, Mariusz Semczuk1, Feng Zhu2, Hans Schuessler2,
Theodor

W. Hansch1 and Thomas Udem1

1Max-Planck-Institut fur Quantenoptik, Hans-Kopfermann-Strasse 1, D-85748
Garching

2Department of Physics, Texas A&M University, College Station, Texas 77843, USA

Recent developments of XUV frequency combs [1],[2] open up the possibility of
high

resolution spectroscopy in the XUV wavelength regime. The 1s-2s two photon
transition

in hydrogen-like Helium at 60 nm is a particular interesting candidate allowing
a further

test of bound state QED. Our proposed spectroscopy scheme is based on the
detection

of ionization events out of the 2s state and sympathetic cooling by co-stored
Magnesium

ions in a RF-trap. Experimental progress is presented, including an absolute
frequency

measurement on cooling transitions in Mg+.

References

[1] C. Gohle et. al., Nature 436, 234 (2005)

[2] R. J. Jones et al., PRL 94, 193201 (2005)

CP 116

138

Probing isotope eŽects in chemical reactions using

single ions

Peter F. Staanum1, Klaus H¿jbjerre1, Roland Wester2 and Michael Drewsen1

1Department of Physics and Astronomy, University of Aarhus, Aarhus, Denmark

2Physikalisches Institut, UniversitÄat Freiburg, Freiburg, Germany

Isotope eŽects often play an important role for the outcome of chemical
reactions. For

instance the chemical composition of interstellar clouds is strongly in°uenced
by isotope

eŽects in certain reactions [1]. In laboratory experiments, isotope eŽects
observed in

isotopic analogs of chemical reactions can provide important information about
details of

the reaction dynamics.

Here we present a recent study of isotope eŽects, in reactions between Mg+ in
the 3p 2P3=2

excited state and molecular hydrogen at thermal energies, through single
reaction events

observed in a Paul trap [2]. From only ť250 reactions with HD, the branching
ratio

between formation of MgD+ and MgH+ is found to be larger than 5. From additional
65

reactions with H2 and D2 we ¯nd that the overall decay probability of the
intermediate

MgH+

2 , MgHD+ or MgD+

2 complexes is the same. These results suggest that the observed

isotope eŽect in reactions with HD arise through a dynamic mechanism in the exit
channel

of the reaction, which may also explain the isotope eŽect observed in reactions
with ground

state Mg+ ions at much higher collision energies [3].

Our study shows that few single ion reactions can provide quantitative
information about

branching ratios and relative reaction rate coeącients in ion-neutral reactions.
Hence,

the method is particularly well suited for reaction studies involving rare
species, e.g.,

rare isotopes or short-lived unstable elements, as well as for studies involving
state pre-

pared molecular ions [4], more complex molecular ions [5; 6] or of
astrophysically relevant

reactions [7; 8].

References

[1] T. J. Millar, Space Science Reviews 106, 73 (2003).

[2] P. F. Staanum, K. H¿jbjerre, R. Wester and M. Drewsen, arXiv:0802.2797v1.

[3] N. Dalleska, K. Crellin and P. Armentrout, J. Phys. Chem. 97, 3123 (1993).

[4] I. S. Vogelius, L. B. Madsen and M. Drewsen, Phys. Rev. Lett. 89, 173003
(2002);

Phys. Rev. A 70, 053412 (2004).

[5] A. Ostendorf et al., Phys. Rev. Lett. 97, 243005 (2006).

[6] K. H¿jbjerre et al., Phys. Rev. A 77, 030702(R) (2008).

[7] D. Gerlich, E. Herbst and E. RoueŽ, Planetary and Space Science 50, 1275
(2002).

[8] S. Trippel et al. Phys. Rev. Lett. 97, 193003 (2006).

CP 117

139

Laser cooling of unbound atoms in nondissipative

optical lattice

N. A. Matveeva1, A. V. Taichenachev1;2, A. M. Tumaikin1 and V. I. Yudin1;2.

1 Novosibirsk State University

Pirogova 2, 630090 Novosibirsk, Russia

2Institute of Laser Physics SB RAS

Lavrenteva 13/3, 630090 Novosibirsk, Russia

E-mail: matveeva1314@ngs.ru

Laser cooling of neutral atoms plays a very important role in optical metrology.
In particular,

the transversal cooling (collimation) of an atomic beam below ¹K would allow one

to achieve the higher precision and stability in the modern atomic frequency
standards

(atomic fountains, atomic clock in condition of microgravitation). This
collimation can

be made by the method of sideband-resolved Raman cooling (SRLC). The experiments

on SRLC of neutral cesium atoms [1] were carried out in the 2D nondissipative
(far-o -

resonance) optical lattice with pre-cooling in a near-resonance lattice, which
complicated

experimental realization. Similar experiments on the high-e ective 3D - SRLC
were made

without pre-cooling stage [2], but the exhaustive theoretical explanation of
high cooling

e ciency has not been presented. Then SRLC was applied at the attempt of the
improvement

of the continuous atomic fountain [3]. In these experiments one used 2-D cooling

scheme similar to described in [2]. However, the e ciency of cooling was poor
and appreciably

lower in comparison with the previous results [2]. The causes of this were not

explained. Thus the necessity of more detailed investigation of cooling in
nondissipative

optical lattices has arisen. One of the purposes of such consideration is to nd
the elds

of parameters where cooling mechanisms of unbound and bound atoms co-exist.

In the present work the semiclassical approach is applied for the analysis of
cooling of

unbound atoms with optical transitions J ! J ¡ 1 in a one-dimensional
nondissipative

optical lattice. For slow atoms in the low-saturation limit the analytical
expressions for

coe cients of friction and di usion are obtained for the simplest 1 ! 0
transition. However,

in this case it is necessary to go beyond the slow atom approximation for the
full

description of atomic kinetic. For this purpose the dependence of force on atom
and the

coe cient of di usion on the atomic velocity are found. At the weak Raman
transition the

heating takes place for small velocity that corresponds to the results of the
slow atom approximation.

At the increasing of atomic velocity the direction of kinetic process changes

and cooling occurs. In addition there are the selective velocity Raman
resonances in the

force, that have some speci c features for J ! J ¡ 1 atomic transitions. The
kinetic

temperature is estimated on the base of the numerical solution of Fokker-Plank
equation

for Wigner distribution function.

References

[1] S. E. Hamann, D. L. Haycock, G. Klose et al., Phys. Rev. Letters 80, 4149
(1998)

[2] A. J. Kerman, V. Vuletic, C. Chin, and S. Chu, Phys. Rev. Letters 84, 439
(2000)

[3] G. Di Domenico, N. Castanga, G. Mileti et al., Phys. Rev. A 69, 063403
(2004)

CP 118

140

Investigations on the linjj lin CPT and its application

in quantum sensors

R. Lammegger1, E. Breschi2, G. Kazakov3, G. Mileti2, B. Matisov3 and L.
Windholz1

1Institute of Experimental Physics TU-Graz, Petersgasse16, 8010 Graz

2Laboratoire Temps-Frśequence, University of Neuch^atel, rue A.-L.-Breguet 1,
CH-2000

Neuch^atel

3St. Petersburg State Polytechnic University, Polytechnicheskaya 29, 195251 St.

Petersburg, Russia

Coherent Population Trapping (CPT) is a resonance phenomenon due to a quantum

mechanical interference eŽect in an atomic system. The resonantly driven atomic
level

population is being trapped into a so called dark state, yielding the atomic
medium

transparent for the exciting electromagnetic ¯elds.

We present experimental investigations on the behavior of CPT resonances in
Rubidium

(87Rb Isotope) due to the interaction of a linear polarized bichromatic laser
light (linjj lin

CPT) in presence of longitudinal magnetic ¯elds[1]. In this con¯guration the
coherence

has a quadrupol like nature and is strongly in°uenced by the hyper¯ne structure
of the

excited state. The hyper¯ne structure of the excited states gives rise to
degenerate CPT

resonances. By comparing the multi-level model calculations with the
experimental re-

sults we demonstrate that the quantum interference between the multi-CPT states
is an

essential feature in this interaction scheme.

We investigate the linjj lin CPT signal depending on the relationship of
pressure broad-

ening and laser linewidth. Therefore CPT signals obtained by excitation with a
vertical

surface emitting laser system (linewidth 100MHz) and a system of phase locked
lasers

(linewidth 40kHz) are compared. The experimental and theoretical results allow
us to

quantify the contribution from diŽerent CPT-states to the total linjj lin CPT
signal. Based

on our experiment, we can de¯ne the conditions in which the laser linewidth does
not de-

grade the amplitude of the linjj lin CPT signal and, thus the optimal
performance for

compact atomic clocks and magnetometers based on linjj lin CPT.

References

[1] E. Breschi, G. Kazakov, R. Lammegger, G. Mileti, B. Matisov and L. Windholz,

arXiv:0804.4627v1 [quant-ph]

CP 119

141

Optically Driven Atomic Coherences:

From the Gas Phase to the Solid State

J. Klein, F. Beil, and T. Halfmann

Institute of Applied Physics, Technische Universitat Darmstadt, Germany

Coherent interactions between strong radiation and quantum systems provide
well-estab-

lished tools to control optical properties and processes. Among others,
applications aim

at e cient data storage and processing of optically stored data, e.g. as
required in quan-

tum information processing. Thus, a large number of experimental studies in
quantum

information science have been conducted in atomic media in the gas phase. Only
few ex-

periments on coherent, adiabatic interactions were conducted in solid state
media. Appro-

priate solid materials for such investigations are quantum dots, color centers,
or rare-earth

doped solids. The latter combine the advantages of atoms in the gas phase, i.e.
spectrally

narrow transitions and long dephasing times, with the advantages of solids, i.e.
large den-

sity and scalability. In the talk we present implementations of coherent
interactions in a

rare-earth doped solid, i.e. a Pr:YSO crystal [1]. In particular we report on
the experimen-

tal implementation of stimulated Raman adiabatic passage (STIRAP) in Pr:YSO. Our

data provide clear and striking proof for complete population inversion between
hyper ne

levels in the Praseodymium dopants. Time-resolved absorption measurements serve
to

monitor the adiabatic population dynamics during the STIRAP process. We will
discuss

the possibilities of STIRAP and related techniques to drive atomic coherences in
the solid

state environment, e.g. for applications in optical and quantum information
processing.

References

[1] J. Klein, F. Beil, and T. Halfmann, Phys. Rev. Lett. 99, 113003 (2007)

CP 120

142

Slowing light and coherent control of susceptibility in

a duplicated two-level system

F.A. Hashmi, M.A. Bouchene

Laboratoire de Collision Agr´egats R´eactivit´e, C.N.R.S UMR 5589, IRSAMC

Universit´e Paul Sabatier, 118 Route de Narbonne, 31062 TOULOUSE, FRANCE

We present a new method of slowing light that can be realized in a double two
level system

by exciting it with two orthogonally polarized light pulses that propagate along
different

axis 1. Spatio-temporal dephasing of the total polarization induces a grating in
the ground

zeeman coherence. The stronger of the two fields (the control field) is
diffracted from this

grating into the direction of the weak probe field compensating for the
absorption of this

latter field. A transparency window is thus created in the absorption spectrum
of the

probe leading to the slowing down of light [Fig. 1(a)]. The transparency window
exhibits

characteristics identical to the one obtained by EIT method. However, the
important

difference between our method and the traditional EIT method is that ours
doesnt rely

on realizing dark state in the system. This may open the possibility of slowing
down light

in more complex atomic media.

-4 -2 0 2 4

-0.4

-0.2

0.0

0.2

0.4

-4 -2 0 2 4

0.0

0.2

0.4

0.6

0.8

1.0

Susceptibility (in units of 2 0k-1)

(in units of )

Re( )

= 0

= 0.3

= 0.6

Im( )

(a) Transparency window for the

probe.

-4 -2 0 2 4

-0.5

0.0

0.5

1.0

Re eff

Im eff

=0

= /2 =3 /4

= /4

-4 -2 0 2 4

-1.0

-0.5

0.0

0.5

-4 -2 0 2 4

-1.0

-0.5

0.0

0.5

eff in units of 2 0k-1

in units of

-4 -2 0 2 4

-0.5

0.0

0.5

1.0

(b) Coherent control of susceptibility.

Figure 1: Real and Imaginary parts of the susceptibility.

is the strength of the control

field, is the detuning for the probe in (a) and detuning of both probe and
control in (b)

For the case when the two fields have the same frequency and the same axis of
propagation,

linear susceptibility vanishes and higher order, phase dependent non-linear
susceptibility

becomes important, allowing coherent control of the optical response of the
medium 2.

Coherent control of the medium gain for double two level system in the
femtosecond

pulse regime has already been discussed 3. Here we demonstrate that for long
pulses the

effective susceptibility for the probe behaves as

lin

e

−2

i where

lin is linear susceptibility

and is the phase difference between two fields. Depending on the relative phase
between

the two fields the system can be converted into an absorber or the gain medium
for the

probe with normal or anomalous dispersion [Fig. 1(b)]. At larger optical
thickness, phase

growth during propagation destroys this coherent control and effective
susceptibility turns

into

lin

,turning an absorber into an amplifier without effecting the dispersion.

1F.A. Hashmi and M.A. Bouchene, Slowing light through Zeeman Coherence
Oscillations in a dupli-

cated two-level system, submitted to Phys.Rev.A (2008)

2F.A. Hashmi and M.A. Bouchene, Coherent control of the effective susceptibility
through wave mixing

in a duplicated two-level system (2008), submitted to Phys.Rev.Lett.

3J.C. Delganes and M.A. Bouchene, Phys. Rev. Lett. 98, 053602 (2007)

CP 121

143

Rydberg excitation of a BoseEinstein condensate

T. Pfau , R. Heidemann,U. Raitzsch, V. Bendkowsky, B. Butscher, R. L¨ow

5. Physikalisches Institut, Universit¨at Stuttgart, Pfaffenwaldring 57, D-70550
Stuttgart,

Germany

t.pfau@physik.uni-stuttgart.de

Rydberg atoms provide a wide range of possibilities to tailor interactions in a
quantum

gas. Here we report on Rydberg excitation of Bose-Einstein condensed 87Rb atoms.
The

Rydberg fraction was investigated for various excitation times and temperatures
above

and below the condensation temperature. The excitation is locally blocked by the
van der

Waals interaction between Rydberg atoms to a density-dependent limit. Therefore
the

abrupt change of the thermal atomic density distribution to the characteristic
bimodal

distribution upon condensation could be observed in the Rydberg fraction. The
observed

features are reproduced by a simulation based on local collective Rydberg
excitations [1].

The excitation dynamics was investigated for a large range of densities and
laser intensities

and shows a full saturation and a strong suppression with respect to single atom

behaviour. The observed scaling of the initial increase with density and laser
intensity

provides evidence for coherent collective excitation. This coherent collective
behaviour,

that was observed for up to several thousand atoms per blockade volume is
generic for

all mesoscopic systems which are able to carry only one single quantum of
excitation [2].

Despite the strong interactions the evolution can still be reversed by a simple
phase shift

in the excitation laser field. We experimentally prove the coherence of the
excitation in

the strong blockade regime by applying an optical rotary echo technique to a
sample of

magnetically trapped ultracold atoms, analogous to a method known from nuclear
magnetic

resonance. We additionally measured the dephasing time due to the interaction

between the Rydberg atoms. [3]

References

[1] R. Heidemann, U. Raitzsch, V. Bendkowsky, B. Butscher, R. L¨ow, and T. Pfau

Rydberg excitation of Bose-Einstein condensates

Phys. Rev. Lett. 100 , 033601 (2008).

[2] R. Heidemann, U. Raitzsch, V. Bendkowsky, B. Butscher, R. L¨ow, L. Santos,
T. Pfau

Evidence for coherent collective Rydberg excitation in the strong blockade
regime

Phys. Rev. Lett. 99, 163601 (2007).

[3] U. Raitzsch, V. Bendkowsky, R. Heidemann, B. Butscher, R. L¨ow, T. Pfau

An echo experiment in a strongly interacting Rydberg gas

Phys. Rev. Lett. 100 , 013002 (2008).

CP 122

144

Progress towards a high-precision measurement of

the g-factor of a single, isolated (anti)proton in a

double Penning trap

S. Kreim1, K. Blaum2

,

3, H. Kracke1, A. Mooser1, W. Quint2, C. Rodegheri1, S. Ulmer2

,

4,

J. Walz1

1Institut f¨ur Physik, Johannes Gutenberg-Universit¨at, 55099 Mainz, Germany

2GSI Darmstadt, 64291 Darmstadt, Germany

3Max-Planck-Institut f¨ur Kernphysik, 69117 Heidelberg, Germany

4Ruprecht Karls-Universit¨at, 69047 Heidelberg, Germany

E-Mail: kreim@uni-mainz.de

This experiment is aimed at measuring the magnetic moment or g-factor of a
single,

isolated proton stored in a cylindrical Penning trap with a relative uncertainty
of 10−9

or better, which will be the first direct measurement of the proton g-factor
ever performed.

Determining the g-factor of a particle results from an accurate measurement

of its cyclotron and spin precession frequency. The Larmor frequency can be
extracted

by inducing radio-frequency transitions between the two spin states in the
homogeneous

magnetic field region of the first, precision Penning trap. The resulting spin
state is then

detected non-destructively in the magnetic bottle field of the analysis trap.
There, the

magnetic moment is coupled to the axial eigenmotion shifting this frequency
according

to the spin direction. The value of the frequency shift scales with the magnetic
moment

of the particle and the strength of the magnetic bottle. Thus, a novel trap
design was

developed which we call hybrid Penning trap [1] to increase the axial frequency
jump to

a detectable range.

To achieve a high-precision determination of the proton g-factor, long storage
times are

required which is realized by performing the experiment in a closed setup at 4K
yielding

extremely low background pressure (p < 10−16 mbar). This environment bears great
challenges

for the electronics needed to non-destructively detect the trapped proton,
however,

it leads to a low electronic noise. In addition, the use of superconductive
resonant circuits

increases the signal-to-noise ratio of the detection system by some orders of
magnitude.

Since the sealed system requires an in-trap creation of protons, a newly
developed cryogenic

electron gun [2] will function as an electron beam ion source permitting the
creation

of protons inside the magnetic field and at 4 K. Commissioning experiments with
electron

gun and fully cabled system will be presented where the performance of the trap
tower and

the thermal behavior of electronic components were examined. At present, the
detection

circuits are implemented to yield spectra of particle clouds shortly.

Besides the proton g-factor, future experiments aim at determining the
antiproton gfactor.

Comparison of the two experimental values will provide a stringent test of CPT

invariance on the baryonic sector. Furthermore, the hybrid trap design enables a
variety

of new experiments such as investigating the magnetic moments of bare light
nuclei like

3He or tritium.

References

[1] J. Verdu et al., LEAP Conf. Proc., 260 (2005), J. Verdu et al., submitted
(2008)

[2] F. Maurer, et al., Nucl. Instr. Meth. B 54, 234 (2005)

CP 123

145

Helium-4 Clusters Doped with Excited Rubidium

Atoms

Robert E. Zillich1, Markku Leino2, Alexandra Viel2

1Institute of Theoretical Physics, Johannes Kepler Universit¨at Linz, Austria

2Institute of Physics of Rennes, UMR 6251 du CNRS, Universit´e de Rennes 1,
France

We report on a quantum Monte Carlo study of helium nanodroplets doped with an
elec-

tronically excited rubidium atom, Rb . Our work is motivated by recent
experiments

conducted in Graz and Freiburg.

The Rb-HeN potential energy surface (PES) is simply a sum of pair potentials if
the Rb

is in the electronic ground state. If Rb is in an electronically excited state
(Rb ), the PES

of Rb HeN is based on the diatomics-in-molecules model, thus it is different
from a pair

potential. Moreover, the spin-orbit coupling cannot be neglected and it is
responsible for

different equilibrium structures when compared with potassium.

We use the diffusion Monte Carlo (DMC) method to obtain ground state energies
along

with different unbiased pair distribution densities. For the first excited state
of Rb, the

PES could accommodate a planar ring of N = 8 helium atoms, but the DMC
simulations

show that only N = 7 atoms fit into the ring, because of the large zero point
motion of

He atoms. Adding more atoms creates a very diffuse second ring.

For simulations at the temperature of large 4He droplets of about T = 0.3 −
0.4K, we

employ the path integral Monte Carlo (PIMC) method. If Rb is in the electronic
ground

state, Rb-HeN is a weakly bound complex. Increasing N to N = 100 it becomes a He

droplet with Rb sitting in a dimple on the surface. For Rb in the first
excited state,

PIMC simulations confirm the DMC results, that a ring of up to 7 He atoms forms
around

the Rb atom.

In order to model the experiments where Rb is excited from the electronic ground
state to

the first excited state, we performed PIMC simulations where we start from
equilibrium

configurations of Rb-HeN and then switch to the PES of the 1st excited state. In
this

case, we do not find any signature of a He ring around Rb , but instead Rb is
promoted

to a very weakly bound, metastable state where it sits in a shallow He dimple.
This result

agrees with the interpretation of recent experiments [1]. We used the same
modeling for

the excitation from the ground state to the 2nd excited state of Rb. In this
case, we

found a clear signature of the formation of a Rb He exciplex, which is weakly
bound to

the cluster of N −1 He atoms. We plan to investigate the dynamics upon such
electronic

excitations of Rb using correlated basis function theory.

References

[1] W. Ernst et al., private communication

CP 124

146

Progress in optically-detected spin-resonance on

helium droplets

M. Koch, J. Lanzersdorfer, G. Aubock, J. Nagl, C. Callegari, and W. E. Ernst

Institute of Experimental Physics, Graz University of Technology, Graz, Austria

We demonstrate the possibility of optically detecting the spin state of alkali
metal atoms

and molecules weakly bound on the surface of helium nanodroplets, immersed in a
magnetic

eld. This allows us to show that the electronic spins of atoms do not relax
within

the timescale of the experiment ( 103 s) and those of molecules do. With this
prerequisite

knowledge, we demonstrate that electron spins on a He droplet can be
manipulated.

We show why Rb do not desorb from the droplet upon laser excitation, and how
this leads

to optical pumping, which we achieve experimentally.

With the addition of a microwave eld, we have just succeeded in optically
detecting

an electron-spin transition, on K atoms; the perturbation due to the helium
results in a

distinct shift of the g value, which we are in the process of accurately
quantifying; the

same measurements will be done on Rb, and the latest results will be presented
at the

meeting.

References

[1] J. Nagl, G. Aubock, C. Callegari and W. E. Ernst, Phys. Rev. Lett. 98,
075301 (2007).

[2] G. Aubock, J. Nagl, C. Callegari and W. E. Ernst, J. Phys. Chem. A 111,
7404 (2007).

[3] G. Aubock, J. Nagl, C. Callegari and W. E. Ernst, submitted to Phys. Rev.
Lett.

(2008).

CP 125

147

Effect of finite detection efficiency

on the observation of the dipole-dipole interaction

of a few Rydberg atoms

I.I.Ryabtsev, D.B.Tretyakov, I.I.Beterov, and V.M.Entin

Institute of Semiconductor Physics, Pr. Lavrentyeva 13, 630090 Novosibirsk,
Russia

E-mail: ryabtsev@isp.nsc.ru

Studies of the long-range interactions in small ensembles of closely placed
Rydberg atoms

are important to implement quantum logic gates of a quantum computer. As such
gates

imply coherent interactions of two Rydberg atoms, or excitation of only one
Rydberg

atom at the dipole blockade, the key issue in these studies is the high
detection efficiency

of Rydberg atoms and the need to distinguish between the signals measured for 1,
2, 3,

etc., atoms with high fidelity.

Selective Field Ionization (SFI) technique [1] is most appropriate to detect
single Rydberg

atoms. However, microchannel plate detectors commonly used in experiments do not
pro-

vide the single-atom resolution. Therefore, in our work we focused on detecting
Rydberg

atoms with a channeltron. In our experiments we have found that the histograms
of its

output pulses have prominent maxima corresponding to 1-5 detected atoms.
Combined

with the post-selection technique, this provides a tool to investigate the
signals measured

in experiments on long-range interactions of definite small numbers of Rydberg
atoms.

We have developed a simple theoretical model [2] describing multiatom signals
that we

measure in the experiments on Stark-tuned resonant dipole-dipole interactions
[1] of a few

Rydberg atoms in an atomic beam and frozen Rydberg gas. We have shown that
finite

efficiency of the SFI detector leads to the mixing up of the spectra of resonant
collisions

registered for various numbers of Rydberg atoms. The formulas are presented,
which help

to estimate an appropriate mean Rydberg atom number for a given detection
efficiency.

The dependences of the measured signals on the number of atoms, excitation
volume,

energy and interaction time were investigated. We have also found that a
measurement

of the relationship of the amplitudes of resonances observed in the one- and
two-atom

signals provides a straightforward determination of the absolute detection
efficiency and

mean Rydberg atom number excited per laser pulse. This method is advantageous as
it

is independent of the specific experimental conditions.

Finally, we have performed the testing experiments on resonant dipole-dipole
interac-

tions Na(37S)+Na(37S)!Na(36P)+Na(37P) in a small excitation volume of a sodium

atomic beam [2] and Rb(nP)+Rb(nP)!Rb(nS)+Rb((n+1)S) in a rubidium magneto-

optical trap. The resonances obtained for 1 to 5 of detected Rydberg atoms have
been

analyzed and compared with the theory. The peculiarities of the obtained results
will be

discussed in this report.

This work was supported by the Russian Academy of Sciences.

References

[1] T.F.Gallagher, Rydberg Atoms, Cambridge University Press, Cambridge
(1994).

[2] I.I.Ryabtsev, D.B.Tretyakov, I.I.Beterov, and V.M.Entin, Phys. Rev. A, 2007,
v.76,

p.012722.

CP 126

148

Energy approach to discharge of metastable nuclei

during negative muon capture

A.V. Glushkov12, O.Yu. Khetselius2, S.V. Malinovskaya2, Yu.V. Dubrovskaya2

1Institute for Spectroscopy of Russian Academy of Sciences, Troitsk, 142090,
Russia

2Odessa University, P.O.Box 24a, Odessa-9, 65009

A negative muon captured by a metastable nucleus may accelerate the discharge of
the

latter by many orders of magnitude [1]. For a certain relation between the
energy range

of the nuclear and muonic levels the discharge may be followed by the ejection
of a muon,

which may then participate in the discharge of the other nuclei. We developed
new,

QED energy approach (EA) to calculating characteristics for the discharge of a
nucleus

with emission of quantum and further muon conversion, which initiates this
discharge.

Traditional process of the muon capture are in details studied earlier and here
is not

considered. The intensities of satellites (decay probability) are linked with
imaginary

part of the "nucleolus core+ proton +muon" system. Three channels should be
taken

into account: 1). radiative purely nuclear 2j-poled transition (probability P1;
this value

can be calculated on the basis of known traditional formula); 2). Non-radiative
decay,

when a proton transits into the ground state and a muon leaves the nuclei with
energy

E = E(p ¡ N1J1) ¡ E(i), where E(p ¡ N1J1) is an energy of nuclear transition,
E(i)

is an energy of bond for muon in the 1s state (P2); 3). A transition of proton
into the

ground state with excitation of muon and emission of the quantum with energy E(p
¡

N1J1) ¡ E(nl) (P3). Under condition E(p-N1J1)>E(i) a probability de¯nition
reduces

to QED calculation of probability of the autoionization decay of the
two-particle system.

Numerical calculation is carried out for the Sc nucleus. The probabilities of
the meso atom

decay for diŽerent transitions: P2(p1=2¡p3=2) = 3:93¢1015, P2(p1=2¡f7=2) =
3:15¢1012,

P2(p3=2¡f7=2) = 8:83¢1014. For above indicated transitions the nucleus must
transit the

momentum no less than 2,4 and 2 according to the momentum and parity rules. If a
meso-

atom is in the initial state p1/2, than the cascade discharge occur with
ejection of muon on

the ¯rst stage and the quantum emission on the second stage. To consider a case
when the

second channel is closed and the third one is opened, suppose: E(p1=2)¡E(p3=2) =
0:92

MeV. Energy of nuclear transition is not suącient to transit the muon into the
continuum

state and it may excite into the 2p state. In this case there is the proton
transition p1/2-

p3/2 with virtual excitation of muon into states of series nd and quantum
emission with

energy EE = Ep(p1=2) + E(1s) ¡ Ep(p3=2) ¡ E(2p). The dipole transition 2p-1s
occurs

with probability: P3 = 1:9 ¢ 1013 s¡1 that is more than probabilities of the
p1/2-p3/2 and

p1/2-f7/2 transitions without radiation.

References

[1] V.I.Gol'dansky, V.S.Letokhov, JETP. 67, 513 (1974); L.N.Ivanov,
V.S.Letokhov, JETP.

70, 19 (1976); A. Glushkov, L.N. Ivanov, Phys. Lett.A. 170, 33 (1992)

[2] A. Glushkov et al, Recent Adv. In Theory of Phys. and Chem Systems
(Springer).

15, 301 (2006).

[3] A.V.Glushkov, S.V.Malinovskaya, In: New projects and New lines of research
in Nu-

clear Phys., eds.Fazio G.,Hanappe F., World Sci.,Singapore, 242 (2003); Nucl.
Phys. A.

734, 21 (2004)

CP 127

149

Resonance phenomena in heavy ions collisions and

structurization of positron spectrum

A.V. Glushkov12

1Institute for Spectroscopy of Russian Academy of Sciences, Troitsk, 142090,
Russia

2Odessa University, P.O.Box 24a, Odessa-9, 65009

A great interest to this topic has been, in particular, stimulated by
inaugurating the

heavy-ion synchrotron storage cooler ring combination SIS/ESR at GSI [1]. The
known

discovery of existence of a narrow and unexpected e+ line in the positron
spectra obtained

from heavy ions collisions near the Coulomb barrier. Here a consistent uni¯ed
QED ap-

proach is developed and applied for studying the low-energy heavy ions
collision, including

the electron- positron pair production (EPPP) process too. To calculate the
heavy ions

(atoms, nuclei) (EPPP) cross-section we use modi¯ed versions of the relativistic
energy

approach, based on the S-matrix Gell-Mann and Low formalism and QED operator
per-

turbation theory [2]. The nuclear subsystem and electron subsystem has been
considered

as two parts of the complicated system, interacting with each other through the
model

potential. The nuclear system dynamics has been treated within the Dirac
equation with

eŽective potential. All the spontaneous decay or the new particle (particles)
production

processes are excluded in the 0th order. Resonance phenomena in the nuclear
system

lead to the structurization of the positron spectrum produced. Analysis of data
for cross-

section at diŽerent collision energies (non-resonant energies, resonant ones,
corresponding

to energies of s-resonances of compound U-Cf, U-U, U+Ta system) is presented.
The spe-

cial features are found in the diŽerential cross-section for the nuclear
subsystem collision

energies, for example, for U-U susyem as follows: (a) E1 = 162.0 keV (3rd
s-resonance),

(b) E1 = 247.6 keV (the 4th s-resonance), (c) E1=352,2 keV (5th upper
s-resonance).

References

[1] J.Reinhardt, U. Muller, W.Greiner, Z. Phys.A. 303, 173 (1981); V.Zagrebaev,
W.Greiner,

J. Phys. G. 34, 1 (2007); V.Zagrebaev, V.Samarin, W.Greiner, Phys.Rev.C.
75,035809

(2007); A.Glushkov, JETP Lett. 55, 95 (1992); Low Energy Antiproton Phys., AIP

Serie. 796, 206 (2005); A.Glushkov, L.Ivanov, Phys.Lett.A. 170, 33 (1992);
L.Ivanov,

A.Glushkov etal, Preprint Inst.for Spectroscopy RAS, AS-5, Moscow (1991);
L.Ivanov,

T.Zueva, Phys.Scr. 43, 374(1991).

[2] A. Glushkov, et al, J. Phys. CS. 11, 188 (2004); 11, 199 (2004); 35, 420
(2005);

Int.J.Quant.Chem. 104, 512 (2005); 104, 562 (2005).

CP 128

150

Dynamics of the resonant levels for atomic and

nuclear ensembles in a laser pulse: optical bi-stability

eŽect and nuclear quantum optics

O.Yu. Khetselius

Odessa University, P.O.Box 24a, Odessa-9, 65009, Ukraine

Present paper has for an object (i) to carry out numerical quantum computation
of a tem-

poral dynamics of populations diŽerences at the resonant levels of atoms in a
large-density

medium in a non-rectangular form laser pulse and (ii) to determine possibilities
that fea-

tures of the eŽect of internal optical bi-stability at the adiabatically slow
modi¯cation of

eŽective ¯led intensity appear in the sought dynamics. It is known that the
dipole-dipole

interaction of atoms in dense resonant mediums causes the internal optical
bi-stability at

the adiabatically slow modi¯cation of radiation intensity. The experimental
discovery of

bistable co-operative luminescence in some matters, in crystal of Cs3Y2Br9Y b3+
particu-

larly, showed that an ensemble of resonant atoms with high density can manifest
the eŽect

of optical bi-stability in the ¯eld of strong laser emission. The Z-shaped eŽect
is actually

caused by the ¯rst-type phase transfer. On basis of the modi¯ed Bloch equations,
we sim-

ulate numerically a temporal dynamics of populations diŽerences at the resonant
levels of

atoms in the ¯eld of pulse with the non-rectangular ch form. Furthermore, we
compare

our outcomes with the similar results, where there are considered the
interaction between

the ensemble of high-density atoms and the rectangularly- and
sinusoidally-shaped pulses.

The modi¯ed Bloch equations describe the interaction of resonance radiation with
the en-

semble of two-layer atoms taking into account the dipole-dipole interaction of
atoms [1].

A fundamental aspect lies in the advanced possibility that features of the eŽect
of inter-

nal optical bi-stability at the adiabatically slow modi¯cation of eŽective ¯led
intensity for

pulse of ch form, in contrast to the pulses of rectangular form, appear in the
temporal

dynamics of populations' diŽerences at the resonant levels of atoms. Modelling
nuclear

ensembles in a super strong laser ¯eld provides opening the ¯eld of nuclear
quantum optics

[2,3].

References

[1] A. Glushkov, O. Khetselius et al, J. Phys.CS. 35, 420 (2006)

[2] A. Glushkov, O. Khetselius, Recent Adv. in Theory of Phys. and Chem. Syst.

(Springer). 18 (2008)

[3] A. Glushkov, O. Khetselius, S. Malinovskaya, Europ. Phys. Journ. 32 (2008)

CP 129

151

Spectroscopy of the hadronic atoms and superheavy

ions: Spectra, energy shifts and widths, hyper¯ne

structure

A.V. Glushkov12, O.Yu. Khetselius2, E.P. Gurnitskaya2, Yu.V. Dubrovskaya2,,

D.E.Sukharev2

1Institute for Spectroscopy of Russian Academy of Sciences, Troitsk, 142090,
Russia

2Odessa University, P.O.Box 24a, Odessa-9, 65009

Paper is devoted to calculation of the spectra, radiative corrections, hyper¯ne
structure

parameters for exotic hadronic atoms and heavy ions with account of the de¯nite
nu-

cleus structure modelling. One of the main purposes is establishment a
quantitative link

between quality of the nucleus structure modelling and accuracy of calculating
energy

and spectral properties of systems. We apply our numerical code [1,2] to
calculating

spectra of the hadronic (pion, kaon, hyperon) atoms. A new, highly exact, ab
initio ap-

proach [2] to relativistic calculation of the spectra for superheavy ions with
an account

of relativistic, correlation, nuclear, radiative eŽects on the basis of
gauge-invariant QED

perturbation theory is used. Zeroth approximation is generated by the eŽective
ab initio

model functional, constructed on the basis of the comprehensive gauge invariance
proce-

dure [2]). The wave functions zeroth basis is found from the Klein-Gordon (pion
atom)

or Dirac (kaon, hyperon) equation. The potential includes the core ab initio
potential,

the electric and polarization potentials of a nucleus (the Fermi model, the
gaussian form

of charge distribution in the nucleus and the uniformly charged sphere are
considered).

For low orbits there are important eŽects due to the strong hadron-nuclear
interaction

(pion atom). The energy shift is connected with length of the hadron-nuclear
scattering

(scattering amplitude under zeroth energy). For superheavy ions the correlation
correc-

tions of high orders are accounted within the Green functions method. The
magnetic

inter-electron interaction is accounted in the lowest order, the Lamb shift
polarization

part- in the Uhling-Serber approximation, self-energy part - within the Green
functions

method. We carried out calculations :1).energy levels, hfs parameters for
superheavy H

and Li-like ions for diŽerent models of charge distribution in a nucleus and
super heavy

atom Z=114; 3). Shifts and widths of transitions (2p-1s,3d-2p, 4f-3d) in some
pionic and

kaonic atoms (18O, 24Mg etc.) and also K{4He [3].

References

[1] A. Glushkov, L.N. Ivanov, Phys. Lett.A. 170, 33 (1992)

[2] A. Glushkov, et al, J. Phys. CS. 11, 188 (2004); 11, 199 (2004); 35, 420
(2005);

Int.J.Quant.Chem. 104, 512 (2005); 104, 562 (2005).

[3] A. Glushkov, O. Khetselius, S. Malinovskaya, Mol. Phys. 24 (2008); A.
Glushkov, O.

Khetselius, Recent Adv. in Theory of Phys. and Chem. Syst. (Springer). 18
(2008);

EUrop. Phys. Journ. (2008).

CP 130

152

CP 131

153

Radiative data in the Zr I spectrum

G. Malcheva1, K. Blagoev1, R. Mayo2, M. Ortiz2, J. Ruiz2, L. Engstr¨om3, H.
Lundberg3,

S. Svanberg3, H. Nilsson4, P. Quinet5

,

6 and ´E. Bi´emont5

,

6

1Institute of Solid State Physics, 72 Tzarigradsko Chaussee,BG - 1784 Sofia,
Bulgaria

2Department of Atomic, Molecular and Nuclear Physics, Univ. Complutense de
Madrid,

E-28040 Madrid, Spain

3Department of Physics, Lund Institute of Technology, P.O. Box 118, S-221 00
Lund,

Sweden

4Lund Observatory P.O. Box 43, S-221 00 Lund, Sweden

5IPNAS (Bt. B15), University of Lige, Sart Tilman, B-4000 Lige, Belgium

6 Astrophysics and Spectroscopy, University of Mons-Hainaut, B-7000 Mons,
Belgium

E-mail: bobcheva@issp.bas.bg

Radiative data in the Zr I spectrum, in particular radiative lifetimes of
excited states and

transition probabilities of electric dipole (E1) transitions, are of interest
for the determination

of the Zr abundance in stars, including the Sun. These data are also important
for

the investigation of plasmas, particularly the plasmas near the walls in
high-temperature

devices.

In the present work radiative lifetimes for 17 levels belonging to the odd
4d25s5p configuration

are reported. They were measured using a time-resolved laser-induced
fluorescence

(TRLIF) technique [1]. The levels investigated are: y3S1; u3P0

,

1

,

2; v3P1

,

2; t3P1; t3D1

,

2

,

3;

u3F2

,

3

,

4; x3G5 and w3G3

,

4

,

5. A single-step laser- excitation process, either from the ground

state or from appropriate metastable states, was used.

Free zirconium atoms were generated by laser ablation in a vacuum chamber with
10−6-

10−5 mbar background pressure. For the ablation, an Nd:YAG laser with 10 ns
pulse

duration was used. The laser system for the excitation of the Zr I levels
consisted of a

dye laser which had a pulse duration of about 1-2 ns.

For 14 of the investigated states, radiative lifetimes were obtained for the
first time. The

error bars are in the interval 4-10%. Measurements of branching fractions are
also in

progress by means of the Laser Induced Breakdown Spectroscopy (LIBS) technique.

The relativistic Hartree-Fock (HFR) method, as described by Cowan [2], has been
used

to compute radiative lifetimes and transition probabilities and the results are
compared

with the experimental data. In the calculations, core-polarization effects and
extensive

configuration interaction effects have been taken into account.

This work was financially supported by the Swedish Research Council; by the
EU-TMR

access to Large-Scale Facility Programme (contract RII3-CT-2003-506350) and by
the

National Science Fundation of Bulgaria (grant 1516/05).

References

[1] Z. G. Zhang, S. Svanberg, P. Quinet, P. Palmeri and ´E. Bi´emont, Phys. Rev.
Lett.

87, 273001 (2001)

[2] R. D. Cowan, The Theory of atomic Structure and Spectra (University of
California

Press, Berkley, California, USA, 1981)

CP 132

154

Energy levels, oscillator strengths and lifetimes in

Cl IV

G. P. Gupta

Department of Physics, S. D. (Postgraduate) College, Muzaffarnagar 251 001,

(Affiliated to Chowdhary Charan Singh University, Meerut - 250 004), INDIA

E-mail: g p gupta1@yahoo.co.in

Emission lines due to allowed and intercombination transitions in multiply
charged Silike

ions are observed in solar corona and laser produced plasma. The lines arises
from

intercombination transitions have been shown to be very useful, for instant, in
understanding

density fluctuations and elementary processes which occur in both interstellar

and laboratory plasma and the determination of transition energies, oscillator
strengths

and transition probabilities of these lines as needed for a qualitative analysis
of the spectra

are not well known. This is mainly because these weak lines are usually
sensitive to the

theoretical modeling and have been a challenge for the atomic structure theory.

We have calculated the excitation energies, oscillator strengths and transition
probabilities

for electric-dipole-allowed and intercombination transitions among the
fine-structure

levels of the terms belonging to the configurations (1s22s22p6)3s23p2, 3s3p3,
3s23p3d,

3p4, 3s23p4s, 3s23p4p, 3s3p2(2S)4s, 3s3p2(2P)4s, 3s3p2(4P)4s, 3s3p2(2D)4s,
3s23p4d and

3s23p4f of Si-like Clorine, using extensive configuration-interaction (CI)
wavefunctions

[1]. The relativistic effects in intermediate coupling are incorporated by means
of the

Breit-Pauli Hamiltonian [2]. Small adjustments to the diagonal elements of the
Hamiltonian

matrices have been made so that the energy splittings are as close as possible
to the

experiment. From our radiative rates, we have also calculated the radiative
lifetimes of

the levels. In this calculation we have investigated the effects of electron
correlations on

our calculated data, particularly on the intercombination transitions, by
including orbitals

with up to n=5 quantum number. We considered up to two electron excitations from
the

valence electrons of the basic configurations and included large number of
configurations.

These configurations represent all major internal, semi-internal and
all-external electron

correlation effects [3].

The mixing among several fine-structure levels is found to be very strong. These
levels are

identified by their eigen-vector composition [4]. The energy splitting of 85
fine-structure

levels, oscillator strengths, transition probabilities for
electric-dipole-allowed and intercombination

transitions and the lifetimes of several fine-structure levels are presented and

compared with available experimental levels and the other theoretical results.
Significant

differences between our calculated and the other sophisticated theoretical
lifetimes for

several fine-structure levels are discussed.

References

[1] A. Hibbert, Comput. Phys. Commun. 9, 141 (1975)

[2] R. Glass, A. Hibbert, Comput. Phys. Commun. 16, 19 (1978)

[3] I. Oksuz, O. Sinanoglu, Phys. Rev. 181, 42 (1969)

[4] G. P. Gupta, K. M. Aggarwal, A. Z. Msezane, Phys. Rev. A70, 036501 (2004)

CP 133

155

Large scale CIV3 calculations of fine-structure

energy levels and lifetimes in Al-like copper

G. P. Gupta1 and A. Z. Msezane2

1Department of Physics, S. D. (Postgraduate) College, Muzaffarnagar 251 001,

(Affiliated to Chowdhary Charan Singh University, Meerut - 250 004), INDIA

2Department of Physics and Center for Theoretical Studies of Physical Systems,

Clark Atlanta University, Atlanta, Georgia 30314, USA

E-mail: g p gupta1@yahoo.co.in

We have performed large scale CIV3 calculations of excitation energies from
ground states

for fine-structure levels as well as of oscillator strengths and radiative decay
rates for all

electric-dipole-allowed and intercombination transitions among the
fine-structure levels

of the terms belonging to the configurations (1s22s22p6)3s23p, 3s3p2, 3s23d,
3p3, 3s3p3d,

3p23d, 3s3d2, 3p3d2, 3s24s, 3s24p, 3s24d, 3s24f, and 3s3p4s of Cu XVII, using
very extensive

configuration-interaction (CI) wave functions [1]. The important relativistic
effects

in intermediate coupling are incorporated by means of the Breit-Pauli
Hamiltonian which

consists of the non-relativistic term plus the one-body mass correction, Darwin
term, and

spin-orbit, spin-other-orbit, and spin-spin operators [2]. The errors, which
often occur

with sophisticated ab initio atomic structure calculations, are reduced to a
manageable

magnitude by adjusting the diagonal elements of the Hamiltonian matrices. In
this calculation

we have investigated the effects of electron correlations on our calculated
data,

particularly on the intercombination transitions, by including orbitals with up
to n=5

quantum number. We considered up to three electron excitations from the valence
electrons

of the basic configurations and included large number of configurations (1164)
to

ensure convergence.

Our adjusted excitation energies, including their ordering, are in excellent
agreement

with the available experimental results [3]. The enormous mixing among several
finestructure

levels makes it very difficult to identify them correctly. Perhaps, that may

be the reason for the lack of experimental results for these levels. We believe
that our

extensive calculated values can guide experimentalists identify the
fine-structure levels

[4]. From our radiative decay rates, we have also calculated radiative lifetimes
of the finestructure

levels in Cu XVII. Our calculated lifetimes for the levels 3s3p2(4P) are found
to

be in excellent agreement with the experimental results of Trabert et al. [5]
compared to

other available theoretical results. We predict new data for several levels
where no other

theoretical and/or experimental results are available.

References

[1] A. Hibbert, Comput. Phys. Commun. 9, 141 (1975)

[2] R. Glass, A. Hibbert, Comput. Phys. Commun. 16, 19 (1978)

[3] T. Shirai et al., J. Phys. Chem. Ref. Data 20, 12 (1991)

[4] G. P. Gupta, K. M. Aggarwal, A. Z. Msezane, Phys. Rev. A70, 036501 (2004)

[5] E. Trabert et al., J. Opt. Soc. Am. B5, 2173 (1988)

CP 134

156

Levels energies, oscillator strengths, and lifetimes for

transition in Pb III

C. Col´on1, A. Alonso-Medina1, A. Zan´on2 and J. Alb´eniz3

1Dpto. de F´ısica Aplicada, EUITI, Universidad Polit´ecnica de Madrid (UPM),
Spain

2Dpto. de Matem´atica Aplicada, EUITI, UPM Madrid, Spain

3Dpto. de Qu´ımica Industrial y Pol´ımeros, EUITI, UPM Madrid, Spain

E-mail: cristobal.colon@upm.es

Information about the oscillator strengths and lifetimes has applications in
many scientific

fields. Data about atomic properties are relevant not only to spectroscopy, as
these

values are also of interest in a variety of other fields in physics and
technology. In astrophysical

applications this information can be used to determine elemental abundances

from absorption spectra. These data are also essential to calculate the Stark
width and

shift parameters of spectral lines. In previous work [1-3] we have measured and
calculated

experimental an theoretical values for Pb III.

Transition Probabilities and oscillator strengths for several lines of
astrophysical interest

arising from 5d96s26p, 5d106snl, 5d106s2, 5d106p2, 5d106p7s, and 5d106p6d
configurations

and some levels radiative lifetimes of Pb III has been calculated. These values
were

obtained in intermediate coupling (IC) and using ab initio relativistic
Hartree-Fock calculations.

We use for the IC calculations the standard method of least square fitting of

experimental energy levels by means of computer codes from Cowan (1981). The
inclusion

in these calculations of the 5d106p7s and 5d106p6d configurations has
facilitated us

a complete assignment of the levels of energy of the Pb III. The system
considered is

complex, with high Z were both relativistic and correlation effects must be
important.

Least-square fitting of experimental energy levels partially account correlation
effects not

explicitly calculated in our work. Nevertheless and as we already waited, there
are some

noticeable discrepancies between our theoretical values and experimental data of
oscillator

strengths and lifetimes for the resonance lines 1048.9 and 1553.0 °A. These
discrepancies

have been studied with detail in the bibliography and we think that they can be
corrected

with the inclusion of core polarization effects. Oscillator strengths and
radiative lifetimes

obtained, although in general agreement with the rare experimental data [see
e.g. 4-7],

do present some noticeable discrepancies, that are studied in the text.

References

[1] A. Alonso-Medina ,C. Col´on , A. Zan´on, MNRAS 385, 261 (2008).

[2] C. Col´on, A. Alonso-Medina, C. Herr´an-Mart´ınez , J. Phys. B: Atom.
Mol.Opt. Phys.

32, 3887 (1999).

[3] C. Col´on, A. Alonso-Medina, Physica Scripta 62, 132 (2000).

[4] T. Andersen , A. Kirkegard Nielsen, G. Sorensen G., Physica Scripta 6,122
(1972).

[5] W. Ansbacher, E. H. Pinnington, J. A. Kernahan, Can. J. Phys. 66, 402
(1988).

[6] H. -S. Chou, K. -N. Huang K, Chin. J. Phys 35, 35 (1997).

[7] L. J. Curtis et al., Physical Review A 63, 042502 (2001).

This work has been supported by the project CCG07-UPM/ESP-1632 of the UPM. IV

PRICIT of the CAM (Comunidad Aut´onoma de Madrid), SPAIN.

CP 135

157

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CP 136

158

Einstein coeącients for activation barriers of

equilibrium and non-equilibrium processes caused by

Plank radiation

A. Stepanov

Byelorussian State University, National Ozone Monitoring Research and
Educational

Centre, 7-816 Kurchatov Street, 220064 Minsk, Republic of Belarus, E-mail:

stepav@bsu.by

Analytical calculation of Einstein coeącients is made for activation barrier of
the Boltzmann-

Arrhenius model and an activation process model. For the activation process
model an

activation barrier is shown to have discrete energy structure due to its
thermodynamic

equilibrium with thermal radiation. This structure is determined by interaction
of confor-

mation substates of a molecule with thermal radiation. The Boltzmann-Arrhenius
model

represents an activation process as a result of the work of high-energy spectral
components

of thermal equilibrium radiation. The process is realized by overcoming a
potential barrier

with continuous energy structure. However, it is shown, that such process is
essentially

non-equilibrium and hard to achieve at thermal equilibrium radiation [1].

References

[1] A. V. Stepanov, J. Mol. Struct.:THEOCHEM 805, 87 (2007)

CP 137

159

New transition probabilities of astrophysical interest

in triply ionized lanthanum (La IV)

V. Fivet1, ´E. Bi´emont1,2, P. Palmeri1 and P. Quinet1,2

1 Astrophysique et Spectroscopie, Universit´e de Mons-Hainaut, B-7000 Mons,
Belgium

2 IPNAS, Universit´e de Li`ege, Sart Tilman, B-4000 Li`ege, Belgium

E-mail: vanessa.fivet@umh.ac.be

Despite their low cosmic abundances, the lanthanides (Z=57-71) become
increasingly

important in astrophysics because they are strongly enhanced in some chemically
peculiar

(CP) stars. Up to now, triply ionized lanthanides have not been investigated in
stellar

spectra, the main reason being the lack of atomic data. According to Saha
equation

however, these ions are expected to be observed in hot-stars spectra. The main
purpose

of the present work is to fill in this gap and to provide the astrophysicists
with the radiative

data they need for a quantitative investigation of CP-stars high-resolution
spectra.

During the meeting, we will present preliminary results obtained so far for
triply ionized

lanthanum (La IV). The accuracy of the new data will be assessed through
comparison

of the results obtained within the framework of two independent theoretical
approaches,

i.e. the partly relativistic Hartree-Fock method [1] and the fully relativistic
multiconfigurationnal

Dirac-Fock approach [2]. Homologous lighter ions will also be considered for

testing the adopted model.

The present work on La IV is a continuation of a long-term effort carried out at
Mons

University in order to improve the radiative data of the rare-earth (RE)
elements in their

first ionization degrees. Results obtained previously for many RE atoms and ions
are

stored in the database DREAM on a web site of Mons University, Belgium (See [3]
and

the references therein).

References

[1] R.D. Cowan, The Theory of Atomic Structure and Spectra, University of
California

Press, Berkeley (1981)

[2] I.P. Grant, Relativistic Quantum Theory of Atoms and molecules,
Springer-Verlag,

New York (2007)

[3] http://www.umh.ac.be/ astro/dream.shtml

CP 138

160

A new method for determining minute long lifetimes

of metastable levels

J. Gurell1, P. Lundin1, S. Mannervik1, L.-O. Norlin2 and P. Royen1

1Department of Physics, Stockholm University, AlbaNova University Center,
SE-10691

Stockholm, Sweden

2Department of Physics, Royal Institute of Technology, AlbaNova University
Center,

SE-10691 Stockholm, Sweden

Radiative lifetime measurements of metastable states have been performed for
many years

utilizing stored ions. When measuring lifetimes of metastable states in a
storage ring the

signal may be greatly enhanced, compared to that from passive observation, by
actively

inducing transitions with one or more lasers. The basic principle of our laser
probing

technique has been to probe the population of the metastable state as a function
of delay

time after ion injection which gives us a population decay curve, see e.g. Ref.
[1]. The

introduction of lasers also increases the maximum possible measurable lifetime
signi¯-

cantly. Currently the longest radiative lifetime measured at the storage ring
CRYRING

in Stockholm, Sweden, and to the best of our knowledge in storage rings in
general, is

89 s in BaII, see Ref. [2]. For lifetimes longer than this collisional
excitation of stored

ground state ions becomes a problem since after a few seconds of storage the
vast majority

of the population of the metastable state under study will be originating from
ions that

were in the ground state when injected into the storage ring. During the
analysis, this

contribution is subtracted from the total °uorescence which gives a low S/N
ratio, large

uncertainties and eventually limits the maximum possible lifetime measurable.

A new method has therefore been proposed and its advantages concerning more
accurate

lifetime determinations of extremely long lived metastable states demonstrated,
see Ref.

[3]. Instead of monitoring the decay of the population of the metastable state
relative to

ion injection the contribution from collisional excitation is monitored
directly. In contrast

to the metastable state population itself, the collisional excitation grows
stronger with

increased storage time which results in a much higher S/N ratio at longer
storage times

and higher residual gas pressures and as a consequence the maximum possible
radiative

lifetime measurable increases. This technique has so far only been applied in
two studies

with lifetimes ranging from 16 to 32 s, the 5d 2D5=2 state in BaII, see Ref.
[3], and the

b 4P5=2 state in TiII, submitted to J Phys B. This new technique has not yet
been pushed

to its limit but lifetimes of a few minutes will most probably be possible to
measure.

References

[1] P. Lundin, J. Gurell, L.-O. Norlin, P. Royen, S. Mannervik, P. Palmeri, P.
Quinet,

V. Fivet and śE. Biśemont PRL 99 213001 (2007)

[2] J. Gurell, E. Biśemont, K. Blagoev, V. Fivet, P. Lundin, S. Mannervik, L.-O.
Norlin,

P. Quinet, D. Rostohar, P. Royen and P. Schef PRA 75 052506 (2007)

[3] P. Royen, J. Gurell, P. Lundin, L.-O. Norlin and S. Mannervik PRA 76
030502(R)

(2007)

CP 139

161

Lifetime measurements of metastable states of

astrophysical interest

J. Gurell1, P. Lundin1, S. Mannervik1, L.-O. Norlin2, P. Royen1, P. Schef1, H.
Hartman3,

A. Hibbert4, H. Lundberg5, K. Blagoev6, P. Palmeri7, P. Quinet7;8 and śE.
Biśemont7;8

1Department of Physics, Stockholm University, AlbaNova University Center,
SE-10691

Stockholm, Sweden

2Department of Physics, Royal Institute of Technology, AlbaNova University
Center,

SE-10691 Stockholm, Sweden

3Lund Observatory, Lund University, Box 43, 22100 Lund, Sweden

4Department of Applied Mathematical and Theoretical Physics, Queen's University,

Belfast BT7 1NN, Northern Ireland

5Department of Physics, Lund Institute of Technology, Box 118, 22100 Lund,
Sweden

6Institute of Solid State Physics, Bulgarian Acad. of Sciences, 72 Tzarigradsko

Chaussee, BG-1784 So¯a, Bulgaria

7Astrophysique et Spectroscopie, Universitśe de Mons-Hainaut, B-7000 Mons,
Belgium

8IPNAS, Universitśe de Liľege, Sart Tilman B15, B-4000 Liľege, Belgium

Under normal laboratory conditions metastable states are commonly depleted
through

collisions between particles. Under astrophysical conditions, however, low
pressures and

temperatures can make the mean free path of particles so long that ions in
metastable

states have time to decay spontaneously through forbidden transitions which are
usually

not observed in laboratory light sources. Since the intensity of these forbidden
lines are

strongly dependent on the frequency of particle collisions these transitions may
be used

as density probes of dilute astrophysical plasmas.

The super massive star ´ Carinae has attracted much attention recently. One of
the

surrounding regions referred to as the Strontium-¯lament contains ejecta from ´
Carinae

and shows a number of forbidden lines from Sr II, Fe I, Ti II and Sc II. In
order to use

these lines as probes transition probabilities are needed which are either
calculated or

measured indirectly through lifetime measurements in combination with
experimental

branching fractions.

At the storage ring CRYRING in Stockholm, Sweden, lifetime measurements of
metastable

states have been performed for many years (see e.g. Ref. [1]) and recently
lifetimes of

metastable levels in Sc II and Ti II have been measured and submitted for
publication

together with new calculations. The experimental technique utilizes a laser
probing tech-

nique and the resulting lifetimes are used in combination with astrophysical
branching

fractions deduced from spectra recorded with the STIS spectrograph on board the
Hubble

Space Telescope, see e.g. Ref. [2]. All measurements, which are ranging from
1-24 s, are

complemented by theoretical calculations showing good agreement with the
experimental

values.

References

[1] S. Mannervik, A. Ellmann, P. Lundin, L.-O. Norlin, D. Rostohar, P. Royen and
P.

Schef Phys. Scr. T119 49 (2005)

[2] H. Hartman et al. A&A 397 1143 (2003)

CP 140

162

Spin-exchange e ects in elastic electron scattering

from linear triatomic radicals

M.-T. Lee1, M. M. Fujimoto2, S. E. Michelin3, and I. Iga1

1 Departamento de Qu mica, UFSCar, 13565-905, S~ao Carlos, SP, Brazil

2 Departamento de F sica, UFPR, 81531-990 Curitiba, PR, Brazil

3 Departamento de F sica, UFSC, 88040-900 Florian opolis, SC, Brazil

E-mail: dlmt@ufscar.br

Low-energy electron collisions with atoms, molecules, radicals, and surfaces
are, in general,

strongly in uenced by electron-exchange e ects. Such e ects can be easily
characterized in

the electron-impact spin-forbidden excitations (for instance, singlet-to-triplet
transitions).

Although exchange mechanism is also important in low-energy elastic
electron-molecule

collisions, its e ects is usually masked since most experimental studies are
performed using

unpolarized electron sources and without spin analysis of the scattered beam.
Limited

experimental studies have been reported in the literature over the past years.
For instance,

spin- ip (SF) di erential cross sections (DCSs) for elastic electron scattering
by the Na and

Hg atoms as well as by the open-shell O2 and NO molecules were reported by
Hegemann

et al. [1]. Although signi cant spin-exchange e ects were found for atomic
targets, very

small e ects were observed for O2 and NO. Lately, theoretical studies of da
Paix~ao et

al. [2] have shown that the almost isotropic polarization fractions (SPFs) of
scattered

electrons is mainly caused by the molecular orientation averaging, since gaseous
targets

are randomly oriented in space.

Recently, we reported a theoretical investigation on spin-exchange e ects in
elastic electron

collisions with the open-shell C2O radical [3] using the iterative Schwinger
variational

method (ISVM). In that study, we have shown that the exchange e ects are
strongly enhanced

by the occurrence of resonances. In this sense, the calculated P0/P averaged
over

all orientations are no longer isotropic and deviate signi cantly from unity
particularly at

large scattering angles.

Here, we extend the spin-exchange study to two linear triatomic open-shell
molecules,

namely CNN and NCN. These two targets are isoelectronic of C2O radical with the

ground-state electronic con guration X3 . As in C2O, strong shape resonances
are also

present in the doublet- and quartet-coupling scattering channels for both
targets in the

low-incident energy range [3]. In this work, we report a calculation of spin- ip
(SF)

di erential (DCSs) and integral cross sections (ICSs) as well as
spin-polarization (SPFs)

fractions for elastic electron scattering by CNN and NCN in the (1-10)-eV energy
range.

Our calculated SF DCSs and SPFs as well as the SF ICSs for these two targets
will be

presented during the EGAS.

This work is partially suported by the Brazilian agency CNPq.

[1] T. Hegemann, M. Oberste-Vorth, R. Vogts, and G. F. Hanne, Phys. Rev. Lett.
66

2968 (1991).

[2] F. J. da Paix~ao, M. A. P. Lima, and V. McKoy, Phys. Rev. A 53 1400 (1996).

[3] M. M. Fujimoto, S. E. Michelin, I. Iga, and M.-T. Lee, Phys. Rev. A 73
012714

(2006).

CP 141

163

Spectral properties of interactions in metallic

endohedral fullerenes Li2@C60 and Na2@C60

Zapryagaev S.A., Butyrskaya E.V.

Voronezh State University. Russia

Endohedral fullerenes are of great interest due to their diversity applications
as in technology

so in fundamental research of interatomic interactions. Because of the robust
carbon

cage and its large hollow interior space fullerenes can be used as molecular
containers and

as building blocks of carbon-based nanotechnology. The program Gaussian 03 and
HF

method in basis 3-21G was used in calculation at present work to investigate a
spectral

properties of an interactions of Li2 and Na2 molecules encapsulated in C60
carbon cage

that are produced endohedral metallic fullerenes Li2@C60 and Na2@C60.
Encapsulating

molecules inside fullerene C60 changes a structure and properties, both
molecules as a

carbon skeleton. According of Mulliken population data significant carry of
electronic

density from an encapsulated molecule on fullerene cage is observed. Except
according

of presented calculation a compression of encapsulated Na2 molecule takes place.
This

compression is consequence of steric interaction of multielectronic Na2 system
from a

carbon cage. This effect is not observed at encapsulate inside C60 Li2 molecule
having

the smaller sizes then Na2 molecule. On the contrary the internuclear Li−Li
distance increases,

in comparison with free two-nuclear molecule Li2 that shows an increase Mulliken

charge atoms of lithium inside fullerene.

Redistribution of electronic density changes a picture of an oscillatory
spectrum of the visitors

molecule and the fullerene too. The analysis of the form of oscillations for
metallic

fullerenes has shown, that all normal oscillations can be divided on two groups:
- 6 oscillations

in which atoms of metal take part and 174 oscillations of a carbon skeleton.
Except

of metallic atoms oscillation near balance position, oscillation of a metallic
molecule as

a whole inside fullerene and antiphase oscillations of atoms of an encapsulated
molecule

perpendicularly to nuclear line take place.

Frequencies of normal oscillations of encapsulated molecules Li2 and Na2
according to calculation

are equal: 67, 93, 117, 145, 263 , 290 cm−1 for Li2 and 9, 24, 63, 81, 209, 354
cm−1

for Na2. The symbol notes the frequencies of nuclear oscillations near the
balance position,

equal for the main electronic term X1 +

g of two-nuclear molecules Li2 and Na2

accordingly 352 cm−1 and 159 cm−1. The fullerene spectrum according to downturn

of system symmetry also changes: instead of 4 active in C60 IR modes the number
of

absorption bands in a fullerene spectrum increases. Optimization of metallic
fullerenes

structures and the calculation of IR spectra is executed for a case when metals
are located

on an C2 axis of symmetry, and atoms of carbon in C60 are fixed and for a case
of full

optimization without the requirement of preservation of symmetry. For the case
when

atoms of metal are located on C2 axis, reference of fullerene cage oscillation
according to

a new system symmetry is executed.

CP 142

164

Simulation of fullerene formation

Zapryagaev S.A., Butyrskaya E.V.

Voronezh State University. Russia

The reason why C60 is by far the most abundant fullerene in carbon soot still
remains

unrevealed/ It is well known, that C60 fullerene is not energetically the most
stable cluster

among that clusters can be find in soot. For example C70 and C84 have larger
binding

energies per atom than C60. Hence C60 should be less stable energetically than
some other

fullerenes. Nevertheless, C70 is the second most abundant and C84 the third.
Besides, the

production yields of them are much lower than of C60. These facts imply the
unimportance

of binding energy for the production fullerenes. To elucidate a reason why C60
is the most

abundant one need to unveil the process of fullerenes formation.

There are some formation models - pentagon road, fullerene road, ring
stacking

model and C10 reaction road. Pentagon road model bases on the curling of
graphitic

sheets through the incorporation of pentagons forms fullerenes. Fullerene road
model

assumes that the small fullerenes grow into lager ones through sequential C2
additions.

Ring stacking assumes that fullerenes are formed by sequential stacking of
carbon rings. It

is natural to expect that the C atoms react with each other to form small carbon
clusters

in the early stage of fullerene formation process. That is why the study of
small carbon

cluster is the important stage of fullerene formation.

At present work we optimize the ground -state geometries of small carbon
clusters using

the b3lyp method of Gaussian 03 program and simulate the fullerene formation
according

the C10 reaction road method proposed in [1]

References

[1] Yusuke Ueno and Susumu Saito, Phys Rev. B77, 085403 (2008)

CP 143

165

CROSS SECTIONS OF NEGATIVE ION PRODUCTION IN ELECTRON COLLISIONS

WITH ADENINE MOLECULES

I.I.Shafranyosh, M.I.Sukhoviya, M.I.Shafranyosh, Fedorko R. O.

Department of Physics, Uzhgorod National University, Uzhgorod 88000, Ukraine

We report absolute cross sections for the

formation negative ions resulting from electron

interactions with adenine. Interest in

experimental studies of the processes of electronimpact

ion production in the molecules of

biological relevance is related, first of all, to the

significance of the problem of intracellular

irradiation of biological structures by secondary

electrons produced in the substance in quite

considerable amounts under the influence of

different-type radiation. It has been shown in our

preliminary experiments carried out with the

heterocyclic components of the above molecules

[12] that under electron impact different

physical processes occur: i.e. molecules

excitation, ionization, dissociative excitation and

dissociative ionization. Physical modeling of

these processes and estimation of their

radiobiological consequences require knowledge

of their basic characteristics absolute ionization

cross sections. Reliable data on the ionization

cross sections could be obtained only in the

precise experiment, in which the role of

environment is minimized. Such approach was

applied in this work.

Production of negative ions of adenine

molecules (nucleic acid base) has been studied

using a crossed electron and molecular beam

technique. The method developed by the authors

enabled the molecular beam intensity to be

measured and the electron dependences and the

absolute values of the total cross sections of

production of negative adenine ions to be

determined. A five-electrode electron gun with a

thoriated tungsten cathode was used as an

electron beam source. Electron gun temperature

was about 400K providing gun parameter

stability during operation. Electrons having

passed the interaction region were trapped by a

Faraday cup kept at the positive potential.

Measurements were carried out at the 10-710-6 A

electron beam current and the ΔE1/2~0.3 eV

(FWHM) energy spread. Electron gun was

immersed into the longitudinal magnetic field

(induction B = 1.2⋅102 Tl). An electron energy

scale was calibrated with respect to the resonance

peak of the SF6

ion production, the position of

which determined the zero point of the energy

scale.

Using the technique developed by the authors,

the absolute cross sections of the negative

adenine ions formation have been determined for

electron energy in the interval from 0.4 to 5.0

eV. It has been found that the maximal negativeion

formation cross section σ = 6⋅10-18 cm2 was

observed for an electron energy of 1.2 eV . Main

contribution to the cross section was shown to

result from the dissociative ionization cross

section. It has been noted that due to the

resonance mechanism of the negative adenine

ions formation just at low incident electron

energy considerable disorders in the nucleic acid

macromolecules are probable.

References

[1] Sukhoviya M.I., Slavik V.N., Shafranyosh

I.I.. Biopolym. Cell. 7, 77 (1991) (in

Russian).

[2] Sukhoviya M.I., Shafranyosh M.I.,

Shafranyosh I.I. Spectroscopy of Biological

Molecules: New Directions (Kluwer Acad.

Publ.-Dordrecht /Boston /London) p.281

(1999).

CP 144

166

CP 145

167

Anomalous inhomogeneous broadening and kinetics

properites of DMABN

K. Hubisz, T. Wr oblewski, V.I. Tomin

Institute of Physics, Pomeranian University,

76-200 S lupsk, Arciszewskiego 22B, Poland.

E-mail: tomin@apsl.edu.pl

The anomalously large spectral inhomogeneity of the electronic bands ( 145 nm)

of N, N-dimethylaminobenzonitrile (DMABN) in a polar solution of glycerol has
been

found and investigated [1,2]. In nonpolar solutions there is no substantial
manifestation

of inhomogeneous broadening.

In addition to the local excited (LE) band ( 360 nm), the emission spectra
distinctly

display the band associated with internal change transfer, the CT band having a
maximum

near 460 nm. The most interesting property of spontaneous emission by DMABN is
an

unusually strong dependence of emission bands on the exciting light wavelength
in the

range 290430 nm. The character of the changes relates to both emission bands
and looks

as follows. First, the ratio of the intensity maxima of the components ILE/ICT
decreases

in favour of the charge transfer band. At ex = 350 nm the entire spectrum is
rather

broad and blurred, and the band maximum is displaced to the red side by about 40
nm.

A subsequent increase in ex to 430 nm causes a further red shift of the entire
emission

spectrum to 495 nm. Thus, the resultant shift of the spectrum is anomalously
great and

attains 145 nm, with the dependence of the red shift on the excitation
wavelength being

almost linear.

The excitation spectra also depend substantially on the registration wavelength
reg.

Characteristically, there is an additional structure in these spectra when
recording is

made in the range 390 420 nm.

Emission decay and anisotropy characteristics of these \red forms" excited at
longwave-

length edge of absorption were studied using methods of kinetic picosecond
spectroscopy.

The decay times and anisotropy of emission are close to the corresponding
parameters of

DMABN upon excitation at the absorption maximum near 300 nm. Results support the

conclusion about luminescence nature of registered emission of DMABN at far
antiStokes

excitation.

The given data can be explained taking into account an existence of di erent
conformers

of the solute and dipole-dipole interactions between the solute and solvent
molecules, with

allowance for the statistics of the microenvironment, which leads to the
appearance of a

considerable inhomogeneous broadening of spectra when DMABN is placed into a
polar

solution. Hence, DMABN and some other charge transfer molecules in polar
solution

may exist as a set of various conformers di ering by their solvate shells. Some
of these

conformers possesses absorption and emission spectra well shifted to the
longwavelength

and could be selectively excited on the red edge of absorption band.

References

[1] V.I. Tomin, K. Hubisz, and Z. Mudryk, Z. Naturforsch., A: Phys.Sci. 58, 529
(2003)

[2] V.I. Tomin, Opt.Spectr. 101, 2, 206 (2006)

CP 146

168

Reexamination of the LeRoy-Bernstein formula for weakly

bound molecules

Haikel Jelassi, Bruno Viaris de Lesegno and Laurence Pruvost

Laboratoire Aimé Cotton, CNRS II, bat 505, campus dOrsay

91405 Orsay, France

E-mail: laurence.pruvost@lac.u-psud.fr

The energy law giving the eigen energies of a −cn/Rn − cm/Rm potential (studied
by

LeRoy in 1980 [1]), is revisited. For n = 3, m = 6, an analytical law giving the
density

of states is deduced. In the context of weakly bound levels an energy law giving
the

vibrational number v versus the binding energy ǫ is given. We show that the
well-known

LeRoy-Bernstein formula [2] [3] has to be corrected by additional terms, with
the first

one varying as ǫ, the second one as ǫ2 and the third as ǫ7/6 [4]. The use of
such a law

is discussed in the context of the photoassociation spectroscopy of long range
molecular

levels.

References

[1] Theory of deviations from the limiting near-dissociation behavior of
diatomic molecules,

R. J. LeRoy, J. Chem. Phys. 73, 6003 (1980).

[2] Dissociation energy and long-range potential of diatomic molecules from
vibrational

spacings of higher levels, R. J. LeRoy and R. B. Bernstein, J. Chem. Phys. 52,
3869

(1970).

[3] The Dissociation Energy of the Hydrogen Molecule Using Long-Range Forces, W.
C.

Stwalley, Chem. Phys. Lett. 6, 241 (1970).

[4] Reexamination of the LeRoy-Bernstein formula for weakly bound molecules, H.
Jelassi,

B. Viaris de Lesegno, L. Pruvost, accepted to Phys. rev. A.

CP 147

169

The singlet X ¡ A and X ¡ B absorption coeącient of

the K2 system

F. Talbi, M. Bouledroua, and K. Alioua

Laboratoire de Physique des Rayonnements, Badji Mokhtar University,

B.P. 12, Annaba 23000, Algeria

Transitions from the singlet X1§+

g to the ¯rst excited A1§+

u and B1Śu states of the

potassium dimer are studied quantum mechanically. Using the most recent data for
the

potential-energy curves for the 4s+4s and 4p+4s molecular systems and the
corresponding

dipole transition moments, the reduced absorption coeącients for temperatures
ranging

from 880 to 3000 K have been computed. The simulations of the absorption
coeącient

show that the bound-bound transitions are dominant in the red wing and reveal
the

occurrence of a satellite structure around the wavelength 1049 nm. The
temperature

eŽect on the satellite position and its amplitude has also been investigated and
the results

are compared with recent experimental data.

CP 148

170

Atomic-like shell models for alkali trimers derived

from ab initio calculations

Andreas W. Hauser1, Carlo Callegari1, Wolfgang E. Ernst1 and Pavel Sold´an2

1Institute of Experimental Physics, Graz University of Technology,

Petersgasse 16, A-8010 Graz, Austria

2Charles University in Prague, Faculty of Mathematics and Physics, Department of

Chemical Physics and Optics,

Ke Karlovu 3, CZ-12116 Prague 2, Czech Republic

Alkali metal clusters have received great attention due to their role as bridge
between

atomic and solid state physics. Among the smallest clusters, the trimers are of
special

interest, since these systems provide complex spectra including Jahn-Teller
distortions,

yet the spectra are well defined and still accessible via ab initio
calculations.

The experimental spectra, as well as ab initio calculations, show a regular
pattern of

electronic states. High level ab initio calculations [CCSD(T), CASPT2] provide
detailed

information about the participating electronic orbitals, and allow us to
rationalize the

observed patterns in terms of simplified shell models.

For the low-spin states of K3 the standard electron-droplet model offers a
qualitative

explanation.1 In this simplified picture the electronic states are interpreted
as singleelectron

excitations into delocalized molecular orbitals with typical atomic-like shape.

For the description of the quartet manifolds of K3, K2Rb, KRb2 and Rb3 we
utilize the

eigenstates of a harmonic oscillator in a quantum-dot-like confining potential.2

References:

1) A. W. Hauser, C. Callegari, W. E. Ernst and Pavel Sold´an, J. Chem Phys.,
submitted

2) J. Nagl, G. Aub¨ock, A. W. Hauser, O. Allard, C. Callegari, and W. E. Ernst,
Phys.

Rev. Lett. 100, 63001 (2008)

CP 149

171

First observation and analysis

of the (1; 2)1Ś states of KCs

L. Busevica1, R. Ferber1, O. Nikolayeva1, E. A. Pazyuk2,

A. V. Stolyarov2, and M. Tamanis1

1Laser Centre, University of Latvia, 19 Rainis Boulevard, LV-1586 Riga, Latvia

2Department of Chemistry, Moscow State University, Moscow, 119899, Russia

E-mail: Laureta.Busevica@lu.lv

In spite of the fact that the KCs molecule is among prospective objects for
production of

ultracold polar molecules, empirical data on its ground state potential have
been obtained

only very recently [1]. There are still no experimental spectroscopic data on
any of KCs

excited state, and all existing information comes from ab initio calculations
[2]. We

present ¯rst observation of laser induced °uorescence (LIF) for the (1; 2)1Ś
states of

KCs studied by Fourier transform spectroscopy using a Bruker IFS125HR, with 0.03

cm¡1 resolution. KCs molecules were formed at 280oC in the sealed cylindrical
glass

cell containing K (natural isotope mixture) and Cs metals. The LIF D(2)1Ś ! X1§+

spectra have been excited by tuning within 15280 - 15140 cm¡1 a diode laser with
130

mW Mitsubishi ML101J27 laser diode. The B(1)1Ś ! X1§+ LIF spectra have been

obtained with excitation frequencies 14400 - 14500 cm¡1 by a diode laser with 50
mW

Hitachi HL6750 laser diode. Lasers were mounted in home made external cavity
resonators

(Littrow con¯guration), with a grating serving as a feedback source. Term values
of

the (1; 2)1Ś states in KCs have been obtained by adding transition frequencies
to the

respective ground state (vX; JX)X1§+ term values using accurate X1§+ state
energy

level data from [1]. The dependencies of the (1; 2)1Ś states term values on the
factor

J(J + 1) have been plotted. In particular, for the D(2)1Ś state the rotationless
term

values covered the energy range from ca. 15400 to 16400 cm¡1, spanning the J
range

from 16 to 205. Preliminary vD identi¯cation was suggested. The dependencies
have been

compared with their theoretical counterparts based on calculations in [2]. The
analysis

has revealed a noticeable deviation from regular dependence caused, most
probably, by

spin-orbit interaction of the D(2)1Ś state with the (3)3§+ state and,
especially, with the

very closely lying (2)3Ś state, as predicted in [2]. The work on vibrational
assignment

and potential energy curves construction of the states under study is in
progress.

Support by Latvian Science Council grant No. 04.1308 is gratefully acknowledged
by Riga

team. O.N. acknowledges support from European Social Fund. Moscow team acknowl-

edges support by the Russian Foundation for Basic Researches grant No.
06-03-32330a.

References

[1] R. Ferber, I. Klincare, O. Nikolayeva, M. Tamanis, A. Pashov, H. KnÄockel
and E.

Tiemann, J. Chem. Phys., to be published.

[2] M. Korek et al., Can. J. Phys. 78, 977 (2000); M. Korek et al., J. Chem.
Phys. 124,

094309 (2006); M. Aymar and O. Dulieu, private communications.

CP 150

172

High resolution spectroscopy and IPA potential

construction of a3§+ state in KCs

R. Ferber1, O. Nikolayeva1, M. Tamanis1, K. KnÄockel2, E. Tiemann2, and A.
Pashov3

1Laser Centre, University of Latvia, 19 Rainis Boulevard, LV-1586 Riga, Latvia

2Institute of Quantum Optics, Leibniz University Hannover, Welfengarten 1, 30167

Hannover, Germany

3Department of Physics, So¯a University, 5 J. Bourchier blvd., 1164 So¯a,
Bulgaria

Study of a3§+ states of heteronuclear alkali dimers has a strong motivation in
supplying

necessary spectroscopic data for producing ultra-cold molecular species in their
ground

state. We present the analysis of high resolution laser induced °uorescence
(LIF) spectra

to the a3§+ state of KCs, see also [1]. The °uorescence has been studied using a
Bruker

IFS125HR Fourier transform spectrometer, with a typical resolution of 0.03 cm¡1.
KCs

molecules were produced at 280oC in a sealed cylindrical glass cell containing K
and Cs

metals. For excitation a single mode ring dye laser Coherent 699-21 with
Rhodamine 6G

dye was used as a light source. Excitation frequencies were selected between
16870 cm¡1

and 17280 cm¡1 and measured by a wavemeter (HighFinesse WS6) with about 0.015
cm¡1

accuracy. The laser frequencies were tuned until the LIF signal to the a3§+
state of KCs,

as monitored by the Fourier spectrometer in the preview mode, exhibited a
maximal

value. LIF observed between 13700-14200 cm¡1 revealed clear hyper¯ne structure
and

therefore was attributed as °uorescence to the a3§+ state. In the same spectra
LIF to

the ground state was present as well. Only P and R transitions were observed in
LIF

to both the a3§+ and the X1§+ states. The upper state exited in our experiments
is

most likely (4)1§+ perturbed by (3)3§+ and (2)3Ś states. Term values of the a3§+
state

in KCs have been obtained by subtracting the transition frequencies from the
respective

excited state (v0; J0) term value. This term value was obtained by adding the
energy

of the corresponding level of the X1§+ state, calculated from the analysis in
[1], to the

respective (i.e. originating from the same upper state (v0; J0)) transition
frequencies.

At current research stage we have assigned 681 LIF lines in 48 LIF progressions
to the

a3§+ state spanning v¤ from 1 to 21 and J from 23 to 143. The symbol v¤ means

the preliminary current assignment of vibrational quantum numbers. A ¯rst
empirical

potential of the a3§+ state is presented, obtained by the Inverted Perturbation
Approach

(IPA) method [2]. The work on vibrational assignment and potential energy curve
of the

a3§+ state is still in progress.

Support by Latvian Science Council grant No. 04.1308 is gratefully acknowledged
by the

Riga team. O.N. acknowledges support from European Social Fund. The Hannover
team

acknowledges support through SFB407 by DFG. A. P. acknowledges partial support
from

the Bulgarian National Science Fund Grant No. VUF 202/06.

References

[1] R. Ferber, I. Klincare, O. Nikolayeva, M. Tamanis, A. Pashov, H. KnÄockel
and E.

Tiemann, J. Chem. Phys., to be published.

[2] A. Pashov, W. Jastrzťebski, and P. Kowalczyk, Comput. Phys. Commun. 128, 622

(2000)

CP 151

173

Determination of first-order molecular

hyperpolarizability of ethyl

5-(4-aminophenyl)-3-amino-2,4-dicyanobenzoate

using steady-state spectroscopic measurements and

quantum-chemical calculations

J´ozef Heldt, Marek J´ozefowicz, Janina R. Heldt

University of Gdansk, Institute of Experimental Physics,

ul. Wita Stwosza 57, 80-952 Gdansk, Poland

In recent years, molecules with large optical non-linearities have been
extensively studied

due to their potential applications in various optical devices. Some organic
molecules

with donor and acceptor groups connected by a π-conjugated bridges show very
large

first-order hyperpolarizability (β). The existence of electronically excited
states with

strong intermolecular charge transfer (ICT) character is an essential
prerequisite for large

non-linear optical properties.

Ethyl 5-(4-aminophenyl)-3-amino-2,4-dicyanobenzoate (EAADCy) and its
derivatives, organic

molecules containing separate electron donor and electron acceptor groups,
belong

to biphenyl derivatives in which a large dipole moment change between ground
(S0) and

the first excited (S1) states as well as a large transition moment were
measured. It is well

known that first-order hyperpolarizability (β) depend on several spectroscopic
parameters

of the two-level model of organic molecule (J.L. Oudar, D.S. Chmla, J. Chem.
Phys. 66

(1977) 2664):

β ∝ ΔμegM2

eg

E2

eg

(1)

where Δμeg difference in dipole moment between ground and excited state, Meg
transition

dipole moment, Eeg transition energy. Therefore, in this communication we
present

a scrupulous analysis of the first-order hyperpolarizabilities of molecules
under study. The

calculated (using semiempirical calculations, CAChe WS 5) βtheo values are
discussed in

relationship to the experimental data βexp obtained from steady-state
spectroscopic measurements.

Acknowledgements

This work was partially supported by the research grant of the University of
Gdansk,

BW-5200-5-0051-8.

CP 152

174

Electronic structure of the [Au2(dmpm)(i mnt)]

complex

J. Mu˜niz, L.E. Sansores, A. Mart´ınez, R. Salcedo

Instituto de Investigaciones en Materiales, Universidad Nacional Aut´onoma de
M´exico.

Apartado Postal 70-360, M´exico DF 04510, M´exico

Compound [Au2(dmpm)(i mnt)] was synthesized by Tang et al [1] as part of a
series of

dinuclear gold compounds that have intra and inter molecular AuAu interaction.
In this

work a theoretical study of this complex is presented. Full geometry
optimization at MP2

level was performed on one and two molecules. The basis set used is LANL2DZ for
Au and

6-31++G** for all other atoms. The structural parameters obtained for a single
molecule

show that the aurophilic interaction is present with a AuAu distance of 3.0˚A.
A scanning

of the potential energy surface at the MP2 level was done by changing the
intermolecular

gold gold distance between two units of the compound and a minimum was found at

3.3˚Awith an interaction energy of 5 kcal/mol which is consistent with the
binding energy

found in the experiment on this type of complexes. Excited states calculations
were also

carried out to study the optical spectra observed. The results are in good
agreement

with those found in experiment, the emission and absorption bands are generated
by

Metal Ligant Charge Transfer (MLCT) and Metal Centered Charge Transfer (MCCT)

interactions, respectively.

References

[1] S.S Tang, C.-P. Chang, I.J.B. Lin, L.-S. Liou, J.-C. Wang, Inorg. Chem. 36,
2294

(1997)

CP 153

175

A lecture demonstration of quantum erasing

on a photon-by-photon basis

Todorka L. Dimitrova1 and Antoine Weis2

1Paisii Hilendarski University, Plovdiv, Bulgaria

2Physics Department, University of Fribourg, Switzerland

The introduction of the wave-particle duality in quantum mechanics courses often
starts

by a discussion of the famous Gedankenexperiment in which a double slit is
illuminated

by single photons. The classical interference pattern on the screen can then be
explained

in terms of the superposition of a large number of single photon events, in
which each

of the photons has passed both slits simultaneously. In recent years we have
developed

two lecture demonstration experiments of this eŽect: a ¯rst version using a
double slit

with a single photon CCD camera [1,2], and a second version using two-path
interference

in a Mach-Zehnder interferometer (MZI) combined with photomultiplier detection
[2]. In

the latter apparatus we vary the path diŽerence of the interfering beams
periodically by

modulating one of the MZI mirrors with a piezo-transducer, and displaying the
outgoing

light intensity on an oscilloscope. Using strong light and a photodiode one
observes

smooth fringes, while the use of strongly attenuated light, and a
photomultiplier reveals

the individual photon structure of the fringes. In that case photon clicks can
also be

rendered acoustically. This apparatus can be used to demonstrate many eŽects
related

to single photon interference in an undimmed large auditorium.

Recently we have extended the latter experiment for demonstrating the phenomenon
of

quantum erasing. Interference fringes are a consequence of the
indistinguishability of

the paths taken by the particle in the interferometer. Any attempt to put
individual

labels on the particles in each path leads to a disappearance of interference.
This can be

demonstrated in a simple way by inserting orthogonally oriented linear
polarizers in the

two paths of the MZI. When doing so the interference fringes on the screen are
made to

disappear. However, the which-way information imposed by the polarizers can be
erased

after the particles have left the interferometer. In practice this is realized
by the insertion

of a third polarizer, the eraser, oriented at §45ą before the screen. The
erasing polarizer

destroys the polarization labels and makes the interference reappear, a
phenomenon called

quantum erasing. In terms of classical wave superposition the phenomenon is
readily

understood, but its understanding at the single photon level presents some
diąculties for

students. From a didactical point of view it is a nice example for introducing
the concept

of entanglement: while being in the interferometer the external degree of
freedom (path)

of each photon is entangled with its internal state (polarization).

The versatile apparatus described above can be used to demonstrate quantum
erasing on

a photon-by-photon basis in an impressive manner.

References

[1] A. Weis and R. Wynands, Three demonstration experiments on the wave and
particle

nature of light, PhyDid, 1/2 (2003) 67-73.

[2] T. L. Dimitrova and A. Weis, The wave-particle duality of light: a
demonstration

experiment, Am. J. Phys. 76 (2008) 137-142.

CP 154

176

Stark shift in the Cs clock transition frequency:

A new experimental approach

J.-L. Robyr, P. Knowles, A. Weis

University of Fribourg, Department of Physics, Fribourg, Switzerland

The precision of microwave atomic clocks is approaching the 10−16 level, and at
this

precision, more refined accounting of the perturbations affecting the cesium
hyperfine

level splitting must be carefully considered. The AC Stark shift induced by
blackbody

radiation via the polarizability of the Cs atom is one such disturbance. The
past few

years have seen a renewed interest in the measurement and theoretical
description of that

effect. We report on progress towards the application of coherent population
trapping

(CPT) in a pump-probe experiment on a thermal atomic beam for a new measurement

of the third order scalar and tensor polarizabilities that underlie the
blackbody shift.

The polarizability, , describes the energy shift of a level via E(n, LJ , F,MF )
= −1

2 E2,

and is traditionally expanded in a perturbation series whose first few terms are

= (2)

0 (n,LJ ) + (3)

0 (n, LJ , F) + (3)

2 (n, LJ , F)

3M2

F − F(F + 1)

I(2I + 1)

.

Only the third-order perturbation terms (3)

0 (scalar) and (3)

2 (tensor) create a shift affecting

the Cs hyperfine structure, and hence the clock transition frequency 00(3, 0!4,
0).

Recent examination of the theory underlying the polarizability[1] has corrected
a long

hidden sign error, and several recent measurements of the AC and DC Stark shifts
of

00 are not consistent with each other. We wish to help clarify the situation by
a new

experiment.

The principle of the experimental method is to create a hyperfine coherence
using CPT in

an atomic beam, to allow the coherence to evolve for a certain time in
controlled magnetic

and electric fields, and finally to probe the phase accumulated in the field
region. Part

of the phase difference will be proportional to the differential level shifts
produced by

the applied electric field and thus give access to both the third-order scalar
and tensor

polarizabilities of the Cs ground state. We plan to measure the shifts in all
accessible

MF levels, and not only in the MF=0 clock transition states. A degenerate CPT
version

of the method was successfully used by us to measure[2] the tensor Stark shift
(3)

2 , a

value roughly two orders of magnitude smaller than the scalar (3)

0 which dominates the

contribution to the black body shift.

Details of the apparatus and the physics under study will be presented.

[1] S. Ulzega, A. Hofer, P. Moroshkin, and A. Weis, Europhys. Lett. 76, 1074
(2006)

[2] C. Ospelkaus, U. Rasbach, and A. Weis, Phys. Rev. A 67, 011402 (2003).

CP 155

177

Magnetic Field Imaging With Arrays of Cs

Magnetometers: Technology and Applications

P. Knowlese, G. Bisone,h, N. Castagnae, A. Hofere,

A. Mtchedlishvilil , A. Pazgaleve,l,

1, A. Weise,

and including the PSI nEDM collaborationa

−

l

aPhysikalisch Technische Bundesanstalt, Berlin, Germany

bLaboratoire de Physique Corpusculaire, Caen, France

cJagellonian University, Cracow, Poland

dJoint Institute for Nuclear Research, Dubna, Russia

eUniversity of Fribourg, Switzerland

f Institut Laue Langevin, Grenoble, France

gLaboratoire de Physique Subatomique et de Cosmologie, Grenoble, France

hBiomagnetisches Zentrum Jena, Germany

iKatholieke Universiteit, Leuven, Belgium

jJohannes-Gutenberg-Universit¨at, Mainz, Germany

kTechnische Universit¨at M¨unchen, Germany

lPaul Scherrer Institut, Villigen PSI, Switzerland

1Ioffe Physical Technical Institute, St. Petersburg, 194021, Russia

The precision measurement of magnetic fields is of interest for both applied and
funda-

mental physics. In many of these cases, atomic cesium magnetometers pumped by a
laser

(LsOPM) or by a discharge lamp (LaOPM) and operating via simultaneous
application

of optical and magnetic resonance, have the necessary sensitivity[1]. The shift
from using

multiple lamps to using a single laser (with holographic beam splitting) as a
light source for

driving many sensors has improved the suitability of the LsOPM for use in
multi-channel

applications. A successful effort in the mass production of paraffin
anti-relaxation coated

Cs vacuum cells, along with a compact sensor design which maintains a high
magnetic

sensitivity ( 20 fT/

p

Hz), shows that the multi-sensor ( 50) approach to field imaging

is realistic with LsOPMs. The compact sensors (30 × 40 × 40 mm3) are vacuum com-

patible and, once assembled, relatively rugged and insensitive to vibration and
shock.

Successful all-digital control of the magnetometer, as performed by dedicated
FPGA sys-

tems including real-time feedback between different sensors in the array,
indicates that

the initial hurdles slowing the creation of a fully operational compact
multi-sensor optical

magnetometry array have been overcome.

Developments related to the sensors and their in-array operation will be
detailed. Future

applications, such as the control of the magnetic field stability for the new
neutron electron

dipole moment experiment at PSI as well as in the domain of cardiomagnetic field
imaging,

will be explained.

[1] S. Groeger, A. S. Pazgalev, and A. Weis, Appl. Phys. B 80, 645 (2005).

CP 156

178

Performance of a compact dark state Magnetometer

R. Lammegger1 and L. Windholz1

1Institute of Experimental Physics TU-Graz, Petersgasse16, 8010 Graz

Measuring magnetic ¯elds by means of spectroscopic-optical methods has
advantages in

many respects. E.g. in best case the magnetic ¯eld sensor of an optical
magnetometer can

only be made of a (nonmagnetic) glass cell containing a tiny amount of an alkali
metal

non perturbing the external magnetic ¯eld. Moreover the optical sensor is
working near

room temperature. Thus unlike to the (in common more sensitive) superconducting
quan-

tum interference device (SQUID) magnetometer an extensive cooling down to
cryogenic

temperatures can be avoided.

We consider a compact vertical surface emitting laser (VCSEL) based dark state
Mag-

netometer. In such kind of optical magnetometer the zeeman split (magnetic
sensitive)

components of the coherent population trapping (CPT) resonance spectrum are used
to

determine an external magnetic ¯eld. By applying the Breit-Rabi formula the
value of

the external magnetic ¯eld can be derived directly from the frequency of the
magnetic

sensitive CPT resonance components.

In our investigations the advantages and constraints of such a compact
magnetometer

type in terms of sensitivity, measurement bandwidth, noise and in°uence of
magnetic

¯eld gradients are outlined. E.g. in our actual magnetometer setup a sensitivity
down to

10 pT=

p

Hz is reached.

The work is founded by the Fonds zur FÄorderung der wissenschaftlichen Arbeit
(FWF)

(Project No.: L300-N02)

CP 157

179

Laser-induced transport eŽect and laser induced-line

narrowing mechanism for laser excitation in 87Rb

atomic vapors in a ¯nite-size buŽer-less cell.

A.Litvinov1, G. Kazakov2, B. Matisov2

1A.F. IoŽe Physico-Technical Institute RAS, St.Petersburg, Russia

2St. Petersburg State Polytechnic University, St.Petersburg, Russia

Coherent population trapping (CPT) and double radio-optical resonance (DROR) are

quantum nonlinear eŽects. Both these eŽects are the base for the creation of
high preci-

sion magnetometers and atomic frequency standards.

We study the in°uence of the laser induced transport (LIT) [1] and the laser
induced line

narrowing (LILN) [2] eŽects on the DROR and CPT resonance line shape for
excitation in

87Rb atomic vapors in wall-coated and uncoated cell. We take into account both
hyper¯ne

and Zeeman structures of the ground and the excited states of 87Rb atoms as well
as the

probabilities of spontaneous transitions. We investigate the dependence of the
resonance

shape on the length of the cell, on the type of boundary conditions, on the
polarization

and intensity of laser and microwave ¯elds, and on the laser line width
("narrow-band"

and "broad-band").

Laser induced transport in DROR: The ¯rst the LIT was predicted for three-level

model in [1]. We show that the LIT takes place in buŽer-less cell with real 87Rb
atoms.

The physical essence of the LIT eŽect is the caused by the Doppler eŽect
velocity-

selectivity of the interaction of "narrow-band" laser ¯eld with atoms, resulting
in Bennett

dips and peaks in the velocity distribution of atoms in the ground state
sublevels. Asym-

metry of the two velocity distributions gives rise to the opposite-directed
(along the laser

propagation direction) °uxes of the atoms in the ground state sublevels.
Therefore, a °ux

of the population inversion (or, equivalently, of the longitudinal
magnetization) arises.

This behavior one experimentally can obverse as the transmission peak in the
centre of

the DROR signal [3]. LIT eŽect is most pronounced for "narrow-band" laser
pumping.

Laser induced line narrowing in CPT resonance: The LILN of the CPT resonance

realizes only in the case of excitation by "narrow-band" laser. We established
that for

the LILN mechanism the parameters (the amplitude and width) of the CPT resonance

excited on hyper¯ne transition weakly depend on the cell size and the type of
the coating

[4]. When the components of the laser ¯eld are comparable the CPT resonance
width

depends linearly on the laser ¯eld intensity. This case was investigated in [5]
where

the formation of CPT resonance on Zeeman sublevels was studied. In contrast for
the

electromagnetically-induced transparency (EIT) eŽect (where one laser ¯eld is
drive and

the other - probe) the EIT width increases proportionally to the square root of
the drive

¯eld intensity [6].

This work is supported by INTAS-CNES-NSAU grant, project 06-1000024-9321.

References

[1] B. D. Agap'ev, M. B. Gornyi, and B. G. Matisov, Sov.Phys. JETP 65, 1121
(1987).

[2] M. S. Feld and A. Javan, Phys.Rev. 2, 177 (1969).

[3] A. S. Zibrov, A. A. Zhukov, V. P. Yakovlev et al., JETP Letters 83, 168
(2006).

[4] G. Kazakov, B. Matisov, A. Litvinov, and I. Mazets, J. Phys. B 40, 3851
(2007).

[5] A. Huss, R. Lammegger, and L. Windholz et al., JOSA B 23, 1729 (2006).

[6] A. Javan, O. Kocharovskaya, H. Lee et al., Phys. Rev. A 66, 013805 (2002).

CP 158

180

Population transfer, light storage, and superluminal

propagation by bright-state adiabatic passage

G.G. Grigoryan1, G. Nikoghosyan1, A. Gogyan1,2, Y.T. Pashayan-Leroy2, C. Leroy2,
and

S. Gu´erin2

1Institute for Physical Research, 0203, Ashtarak-2, Armenia

2Institut Carnot de Bourgogne, UMR 5209 CNRS - Universit´e de Bourgogne, BP
47870,

21078 Dijon, France

The practical implementation of quantum information requires to develop
techniques of

mapping of light pulses into the excitation of media in order to allow the
subsequent

retrieval of the stored information. Recently, broad attention has been focused
on the

possibility of light-storage under the conditions of electromagnetically
induced transparency

(EIT), as proposed by Fleischauer and Lukin [1]. The method is based on the

existence of a dark state in Raman interaction of a -type system. We present an
alternative

method for the storage and retrieval of optical information using adiabatic
passage

along a bright state (b-state). We present theoretical calculations
demonstrating that a

light storage can take place in media where EIT does not occur. This method is
achieved

for short pulses of interaction time shorter than the relaxation times. Such a
bright state

allows population transfer by a Stimulated Raman adiabatic passage using an
intuitive

pulse sequence (process named b-STIRAP), as demonstrated in Pr+3Y2SiO5 [2].

In the present work we obtain an analytical solution of the set of
Maxwell-Shr¨odinger

equations describing the propagation of two laser pulses in a -type medium for
an intuitive

pulse sequence. We show that it allows an effective storage and retrieval of an

optical pulse. The probe pulse that is switched on later than the control pulse
propagates

in the medium with the velocity greater than the light velocity (superluminal
propagation).

When the control pulse is switched off, the shape of the probe pulse is mapped
into

the coherence of the lower states. After a subsequent switching on of the
control pulse

the probe pulse is shown to be completely restored.

We have analyzed population transfer process in a medium via b-state during the
pulse

propagation. We show that for specific interaction parameters one can achieve an
efficient

population transfer. We have estimated the maximal length up to which population

transfer is still possible.

References

[1] M. Fleischauer and M.D. Lukin, Phys. Rev. Lett. 84 , 5094 (2000)

[2] J. Klein, F. Beil, and T. Halfmann, Phys. Rev. Lett. 99, 113003 (2007)

CP 159

181

Population switching of Na and Na2 excited states by

means of interference due to Autler-Townes eŽect

C. Andreeva1;2, N. Bezuglov3, A. Ekers1, K. Miculis1, B. Mahrov1, I. Ryabtsev4,

E. Saks1, R. Garcia-Fernandez5, K. Bergmann5

1Laser Centre, University of Latvia, LV-1002 Riga, Latvia

2Institute of Electronics, Bulgarian Academy of Sciences, So¯a 1784, Bulgaria

3Faculty of Physics, St.Petersburg State University, 198904 St. Petersburg,
Russia

4Institute of Semiconductor Physics, 630090 Novosibirsk, Russia

5University of Kaiserslautern, Dept. of Physics, D-67653 Kaiserslautern, Germany

We present our results on the exploitation of interference eŽects for population
switching

of excited states. Our calculations show that spatial distribution of the atomic
excitation

can be controlled by employing the Autler-Townes eŽect [1] in a laser coupling
scheme

enabling Ramsey interference [2]. Interference fringes in the Autler-Townes
spectra have

been reported in [3] for the case of a closed three-level system coupled by a
resonant pulsed

pump laser in the ¯rst excitation step, creating time-varying dressed states,
which were

probed by a simultaneous probe pulse in the second excitation step. In our
experiment,

a supersonic sodium beam is crossed by two cw laser beams, which couple an open
three-

level ladder system. The lasers are focused in such a way that a strong and
short (tightly

focused) pump laser couples the two lower levels jgi and jei , and weak and long
(less

tightly focused) probe laser couples the intermediate jei and the upper level
jfi. The

pump laser thus creates two spatially varying dressed states, whose energy
diŽerence is

determined by the pump ¯eld Rabi frequency and its detuning from resonance.

Our numerical calculations of density matrix equations of motion using the split
propaga-

tion technique [4] show that with this arrangement the spatial distribution of
populations

of excited atomic or molecular states can be precisely controlled by varying the
laser

frequencies and intensities. When the frequencies of both laser are ¯xed, the
excitation

of the upper level can take place at two spatial locations. This leads to two
alternative

excitation pathways of the level jfi , where the probability amplitude of this
level after

the second crossing point is determined by the constructive or destructive
interference

of both excitation pathways. Our simulations show [5] that interference fringes
in the

excitation spectrum of the upper level can be resolved when counter-propagating
laser

beams are used to avoid residual Doppler broadening. We show that moderate
detunings

of the strong dressing laser are favorable for the observation of interference
eŽects. The

experimental realization of the idea is in progress.

The work is supported by the EU TOK Project LAMOL, European Social Fund, Latvian

Science Council, and RFBR Grant 05-02-16216.

References

[1] S.H. Autler, C.H. Townes, Phys.Rev. 100, 703 (1955).

[2] N.F. Ramsey, Molecular Beams (Clarendon, Oxford, 1989).

[3] S.R. Wilkinson, A.V. Smith, M.O. Scully, E. Fry, Phys. Rev. A53 (1), 126
(1996).

[4] M.D. Fiet, J.A. Fleck, A. Steiger, J. Comput. Phys. 47, 412 (1982).

[5] N.N. Bezuglov, R. Garcia-Fernandez, A. Ekers, K. Miculis, L.P. Yatsenko, K.
Bergmann,

"Consequences of optical pumping and interference for excitation and spectra in
a coher-

ently driven molecular ladder system" (in preparation).

CP 160

182

High-rank polarization moments influence on the

CPT resonance obtained on two-level degenerated

system

E. Alipieva, E. Taskova, S. Gateva and G. Todorov

Academician Emil Djakov Institute of Electronics, Bulg. Acad. Sc.,

72 Tzarigradsko Chaussee, 1784 Sofia, Bulgaria

E-mail: alipieva@ie.bas.bg

In two-level degenerated system Coherent Population Trapping (CPT) resonance is
due

to the interference between the Zeeman sub-levels with m=2, created by
interaction

of resonance linear polarized laser beam with the atoms. The resonance is
detected by

sweeping magnetic field B0 around its zero value - Hanle configuration. The
multiphoton

processes and the low relaxation rate of the lower levels allow creation of
coherences

between sub-levels with m>2. The laser field transfers this coherence in the
fluorescence

from the upper level and thus changes the shape of CPT resonance.

The investigations were performed on the D1

87Rb line (F=2!F=1 transition) in an

uncoated cell. The comparative - theoretical and experimental investigation,
performed

of the shapes of the CPT resonances registered in fluorescence shows that the
high-rank

polarization moments (HRPMs, m>2) influence them at low excitation power and at

high excitation powers as well. The HRPMs conversion is proved to cause the CPT

resonance shape peculiarities at the center of the resonance: at low excitation
power,

a specific difference from the Lorentzian shape is observed, while at a high
power of

excitation, an inverted structure is registered [1].

All resonances in Hanle configuration are centered at zero magnetic field. The
integration

of the modulation and coherent spectroscopy allows resonances due to different

polarization moments to be resolved and enlarge the application area of the
investigations

[2,3]. A.c. electromagnetic field (EMF) applied collinearly to the B0 modulates

the frequency difference between the Zeeman sub-levels. The Larmor frequency
becomes:

!=!0+!1cos

t, where

is the EMF frequency. The intensity of the scattered from the

atoms light is modulated and shows resonance increasing when EMF frequency is
multiple

to the Zeeman sub-levels difference. When EMF is applied the side-band resonance
which

corresponds to coherence created between m=+2 and m=−2 Zeeman sub-levels appears

first. The parameters of this resonance in dependence of experimental conditions
were

investigated.

The results of this investigation are interesting for high-resolution
spectroscopy, magnetometry,

and metrology applications.

References

[1] S. Gateva, L. Petrov, E. Alipieva, G. Todorov, V. Domelunksen, V. Polischuk,
Phys.

Rev. A76(2), 025401 (2007).

[2] E. Alexandrov, O. Konstantinov, V. Perel, V. Khodovoy, JETP 45, 503-510
(1963);

[3] S. Pustelny, D.F. Jackson Kimball, S.M. Rochester, V.V. Yashchuk, W. Gawlik,
D.

Budker, Phys. Rev. A73, 023817 (2006).

CP 161

183

Sub-Doppler fluorescence spectroscopy of Cs-vapour

layers with nano-metric thickness

K. Vaseva1, P. Todorov1, S. Cartaleva1, D. Slavov1, S. Saltiel2

1Institute of Electronics, Bulgarian Academy of Sciences, 72 Tzarigradsko Shosse
bld,

1784 Sofia, Bulgaria

2Sofia University, Faculty of Physics, 5 J. Bourchier boulevard, 1164 Sofia,
Bulgaria

E-mail: petkoatodorov@yahoo.com

The extensive study of alkali-vapor layers with nano-metric thickness L has been
made

possible through the development of cells of L ≤ 1 μm , where the thickness of
the vaporlayer

can be varied in an interval around the wavelength λ of the irradiating light
[1]. It

was shown that the width of the fluorescence profiles increases with the cell
thickness [2].

We present experimental and theoretical studies of the fluorescence spectra on
the D2

line of Cs-atomic-layers with L = mλ (m = 0.5, 0.75, 1, 1.25), when irradiated
by narrowband

laser light tuned around λ = 852nm. We use the theoretical model [3] based on

the Optical Bloch Equations and obtain qualitative agreement between the theory
and

the experiment. The atomic systems are separated in two groups: closed and open.
Well

pronounced narrow dip in the fluorescence (superimposed on the top of the
sub-Dopplerwidth

fluorescence profile) is observed experimentally only for the open transitions
suffering

hyperfine/Zeeman optical pumping, and for L ≥ λ. In the case of closed
transition,

non-suffering population loss extremely small peculiarity in the fluorescence
profile is observed

for L = 1.25λ [4]. Systematic comparison is made between the fluorescence
profiles

amplitude and width, estimated theoretically and experimentally. With laser
power the

amplitude and the width of the fluorescence profiles increase, for all cell
thicknesses and

all transitions. In agreement with the previous results [2], the width of the
transition

profiles is growing with L. However, we report here about the following new
peculiarity:

the enhancement rate of the transition width is not constant, namely it is
larger for L

varying in the interval 0.75λ ≤ L ≤ λ than that varying in the interval λ ≤ L ≤
1.25λ.

We show that the width of the fluorescence profiles strongly depends on the
layer thickness

(with variations as small as 213nm). These results can be used for spectral
investigations

of atoms confined in nano volumes, as well as for spectroscopy of miniature gas
discharges.

Authors are grateful to Prof. D. Sarkisyan for providing the nano-cell, as well
as to

INTAS (grant: 06-1000017-9001), Indo-Bulgarian program of cooperation in science
and

technology (grant No. BIn-2/07) and the French-Bulgarian Rila collaboration
(French

grant: 98013UK, Bulgarian grant: 3/10), for the partial support.

[1] D. Sarkisyan, D. Bloch, A. Papoyan, M. Ducloy, Opt. Commun. 200, 201 (2001).

[2] D. Sarkisyan, T. Varzhapetyan, A. Sarkisyan, Yu. Malakyan, A. Papoyan, A.
Lezama,

D. Bloch, M. Ducloy, Phys. Rev. A69, 065802 (2004).

[3] C. Andreeva, S. Cartaleva, L. Petrov, S. M. Saltiel, D. Sarkisyan, T.
Varzhapetyan,

D. Bloch, M. Ducloy, Phys. Rev. A76, 013837 (2007).

[4] K. Vaseva, P. Todorov, D. Slavov, S. Cartaleva, K. Koynov, S. Saltiel, ACTA
PHYSICA

POLONICA A, Vol. 112, No. 5, 865 (2007).

CP 162

184

Absorption in the saturation regime of Cs-vapour

layer with thickness close to the light wavelength

P. Todorov1, S. Cartaleva1, K. Vaseva1, C. Andreeva1, I. Maurin2, D. Slavov1,

S. Saltiel3

1Institute of Electronics, BAS, 72 Tzarigradsko Shosse boulevard, 1784 Sofia,
Bulgaria

2Laboratoire de Physique des Lasers UMR 7538 du CNRS, Universit`e Paris-13,
France

3Sofia University, Faculty of Physics, 5 J. Bourchier boulevard, 1164 Sofia,
Bulgaria

E-mail: petkoatodorov@yahoo.com

Absorption spectrum of an atomic vapour layer, which thickness L is close to the
wavelength

of the irradiating light λ, shows a narrow structure on the Doppler broaden
background.

This is attributed to Dicke narrowing [1,2], which is due to the coherent
contribution

of all velocity group atoms into the narrow absorption signal at the position of
the

central frequency of the transition. This is possible because the Doppler shift
is eliminated

by the transient regime of atom-light interaction when the transient interaction
time is

shorter than the lifetime of the exited state. The maximum contribution of Dicke
effect

is achieved for L = λ/2, while the effect is cancelled at L = λ[2]. It has been
shown that

a revival (with an amplitude lower than that at L = λ/2) of the Dicke narrowing
occurs

for L = (2n+1)λ/2. The maximum amplitude of the Dicke revival is for L =
(3/2)λ[2-5].

We present the absorption spectra in saturation regime on the D2 line of
Cs-vapour-layer

with L = (5/4)λ, irradiated by tunable (around λ = 852nm diode laser light[6].
The

atomic gas is confined in a nano-cell [7]. Different saturation behavior for
closed and open

optical transitions reported before in [6,8,9]is studied for cell thickness L =
(5/4)λ. For

the closed transition, well pronounced Dicke narrowing is observed starting from
low light

intensity and it is preserved even on the saturation deep occurring at high
intensity. On

the contrary, the open transitions do not show Dicke resonance under the same
conditions.

The observations differ from those for L = (3/2)λ [5], where the Dicke revival
is observed

for both closed and open transitions. The result is of basic importance for
revealing of

the influence of the optical pumping/saturation processes to the Dicke effect.

We thank D. Sarkisyan for nano-cell, D. Bloch and M. Ducloy for discussions,
INTAS (gr.

06-1000017-9001) and Rila collaboration (French gr.: 98013UK, Bulgarian gr.:
3/10).

[1] R. H. Romer, R. H. Dicke, Phys. Rev. 99, 532(1955).

[2] G. Dutier, A. Yarovitski, S. Saltiel, A. Papoyan, et. al., Europhys. Lett.
63, 35 (2003).

[3] D. Sarkisyan, T. Varzhapetyan, A. Sarkisyan, et. al., Phys. Rev. A69,
065802(2004).

[4] I. Hamdi, P. Todorov, A. Yarovitski, G. Dutier, et. al., Laser Physics 15,
987 (2005).

[5] S. Cartaleva, K. Koynov, et. al., Proc. 34th EPS Conf., ECA vol.31F, P-4.008
(2007).

[6]C. Andreeva, S. Cartaleva, L. Petrov, et. al., Phys. Rev. A76, 013837 (2007).

[7] D. Sarkisyan, D. Bloch, A. Papoyan, M. Ducloy, Opt. Commun. 200, 201 (2001).

[8] S. Briaudeau, D. Bloch and M. Ducloy, Europhys. Lett. 35, 337 (1996)

[9] S.Briaudeau, S.Saltiel, D. Bloch, M. Ducloy, Phys. Rev, A57, R3169 (1998)

CP 163

185

Dark and bright resonances in large J systems:

example of K2 molecule

M. Auzins, R. Ferber, I. Fescenko, L. Kalvans, and M. Tamanis

Laser Centre, University of Latvia, 19 Rainis Boulevard, LV-1586 Riga, Latvia

We report the results of an experimental as well as theoretical study of the
dark and bright

resonances in the ground state of systems with extremely large angular momentum.
It is

shown that, besides the well-known zero-magnetic field suppression of the
absorption on

Jg = J → Je = J 1, J transitions caused by population trapping in the ground Jg
state,

optical pumping may induce enhanced absorption as well. This occurs if some
conditions

are met on Jg = J→ Je = J + 1 transitions for small magnetic field B values. The
latter effect

becomes more pronounced if the J-value increases and disappears if a substantial
fraction

of the excited molecules can spontaneously decay to a level that is different
from the one

on which the absorption transition started. Bright resonance enhancement is
substantially

stronger for excitation with circularly polarized light than for excitation with
linearly

polarized light. The experiments were carried out with the K2 molecule, and the
results of

our measurements agree reasonably well with numerical simulations that were
based on

the optical Bloch equations for the density matrix [1].

K2 molecules were formed in a glass cell that contained K metal at a temperature
of

170 °C, and which was placed between the poles of an electromagnet that produced
a

magnetic field B up to 10 kG. The Q-type B(1)1Πu ← X1Σ+

g transition to the rovibronic

level with ve = 0 and Je = 104 was excited by a diode laser with a Mitsubishi
ML101J27

laser diode at the 15192.29 cm-1 transition frequency. The laser power in the
cell was about

20 mW and the laser beam width about 2.5 mm. Dark resonances were observed in
the

intensities of linearly polarised laser induced fluorescence with polarization
vectors Eobs

both parallel (Ipar) and orthogonal (Iort) to the exciting laser radiation
polarization vector

Eexc, which was orthogonal to B. We detected well pronounced dark resonance
signals,

with larger contrast in Ipar by about 30% , and signal width about 6 kG, which
agreed with

theoretical predictions. Bright resonances had been neither detected nor
predicted

previously for such a system because of the presence of leak transitions to
the Ji-levels

other than the pumped Jg transition.

The authors are grateful for the support from the Latvian State Research
programme in

Material Science 1-23/50 and from the ERAF grant

VPD1/ERAF/CFLA/05/APK/2.5.1/000035/018.

References

[1] K. Blush and M. Auzins, Phys. Rev. A 69, 063806 (2004).

CP 164

186

F-resolved bright and dark magneto-optical

resonances at the cesium D1 line

M. Auzinsh, R. Ferber, F. Gahbauer, A. Jarmola, and L. Kalvans

The University of Latvia, Laser Centre, 19 Rainis Boulevard, LV-1586 Riga,
Latvia

jarmola@latnet.lv

We present detailed experimental and theoretical studies of F-resolved bright
and dark

magneto-optical resonances at D1 excitation of atomic cesium in a vapor cell
[1]. Although

these effects have been known for some time [2,3], experimental measurements
[4,5] did

not agree with theoretical predictions [6,7]. Previously studied systems have
been difficult

to model because several hyperfine levels contributed to the signal
simultaneously. The

advantage of the cesium D1 line system considered here is that the hyperfine
splitting of

the excited 6P1/2 state exceeds the Doppler width and therefore the hyperfine
transitions

from ground state levels Fg = 3, 4 to excited state levels Fe = 3, 4 can be
studied

individually despite Doppler broadening.

Cesium atoms in a vapor cell were excited by linearly polarized laser radiation
from

an external cavity diode laser and the laser induced fluorescence was detected
with a

photodiode in a direction perpendicular to the laser propagation and
polarization. The

magnetic field in the observation direction was scanned by means of a Helmholtz
coil.

The laboratory magnetic field in the other directions was compensated by two
other

Helmholtz coils. Experimentally obtained signals for various laser power
densities and

transit relaxation times were compared to the results of a theoretical
calculation based on

the optical Bloch equations, which averages over the Doppler contour of the
absorption

line and accounts for the contribution of all hyperfine levels, as well as
mixing of magnetic

sublevels in an external magnetic field.

In contrast to previous studies which could not resolve the hyperfine
transitions, in this

study there is excellent agreement between experiment and theory regarding the
sign

(bright or dark), contrast, and width of resonance. The results thus support the
theoretical

description of these resonances originally proposed in [6,7]. Renewed confidence
in the

theoretical underpinnings of these resonances and a detailed theoretical model
could aid

in the design of optical devices based on this effect.

We acknowledge support from the Latvian National Research Programme in Material
Sciences

Grant No. 1-23/50, the University of Latvia grant Y2-ZP04-100, the ERAF grant

VPD1/ERAF/CFLA/05/APK/2.5.1./000035/018, and the INTAS projects 06-1000017-

9001 and 06-1000024-9075. F. G., A. J., and L. K. acknowledge support from the
ESF.

References

[1] M. Auzinsh, R. Ferber, F. Gahbauer, A. Jarmola, and L. Kalvans, arXiv.org,
arXiv:0803.0201.

[2] R. W. Schmieder et al.,Phys. Rev. A 2, 1216 (1970).

[3] G. Alzetta, A. Gozzini, L. Moi, and G. Orriols, Il Nuovo Cimento B 36, 5
(1976).

[4] G. Alzetta et al., Journal of Optics B 3, 181(2001).

[5] A. V. Papoyan et al., J. Phys. B 36, 1161 (2003).

[6] F. Renzoni et al., Phys. Rev. A 63 065401 (2001).

[7] J. Alnis and M. Auzinsh, J. Phys. B 34, 3889 (2001).

CP 165

187

EŽects of hyper¯ne structure on the Autler-Townes

splitting

T. Kirova1, A. Ekers1, N. N. Bezuglov1;2, I. I. Ryabtsev3 , K. Blushs1, and M.
Auzinsh1

1 Laser Centre, University of Latvia, LV-1002 Riga, LATVIA

2 Faculty of Physics, St.Petersburg State University, 198904 St. Petersburg,
RUSSIA

3 Institute of Semiconductor Physics SB RAS, 630090, Novosibirsk, RUSSIA

The Autler-Townes (AT) eŽect is associated with its typical doublet structure in
the

excitation spectrum [1], which is due to the dressing of two energy levels by
strong coherent

radiation ¯eld [2]; the dressed states can be observed by an auxiliary weak
probe ¯eld

coupled to some third level. It has been extensively studied in detail in atoms
[3] and less

extensively also in [4] molecules.

In our recent work [5] we have extended the studies of AT eŽect to atomic and
molecular

systems where hyper¯ne structure is present. In the case of a three-state ladder
with

hyper¯ne structure in Na coupled by two laser ¯elds, simulations based on a
theoreti-

cal model of solving the optical Bloch equations (OBE's) [6] show that
application of a

suąciently strong coupling between the intermediate and the ¯nal states results
in full

resolution of the mF Zeeman sublevels of the hyper¯ne levels F. This resolution,
however,

vanishes if the hyper¯ne levels can not be initially resolved spectroscopically,
which is the

case for most molecular systems.

Currently, work is in progress to understand the above eŽects in the case of
both resolved

and unresolved hyper¯ne structure and to predict possible experimental
applications. Be-

sides OBE's we employ an alternative method treating the laser-atom system by
solving

the Shrdinger's equation to obtain the time evolution of the probability
amplitudes. Com-

parison with the simulations based on solving the OBE's shows the same energy
positions

of the mF Zeeman sublevels under the action of a strong laser ¯eld but diŽerent
widths

and intensities of the AT peaks, since no cascading due to spontaneous emission
is in-

cluded. Simulations based on Shrdinger's equation show that the increase of the
coupling

¯eld strength, compared to the separation between the hyper¯ne components, leads
to

rapid decrease (and eventually vanishing) of the intensity of all AT peaks
besides the two

side ones. The latter is explained in view of the creation of multiple dark
states in a

multilevel system coupled by a strong ¯led.

Support by the EU FP6 TOK project LAMOL, ERDF project S35-ESS38-100, European

Social Fund, Latvian Science Council, and RFBR grant No. 08-02-00220 is
acknowledged.

References

[1] S. H. Autler and C. H. Townes, Phys. Rev. 100, 703 (1955)

[2] C. Cohen-Tannoudji et al., Atomo-Photon Interactions, (Wiley, New York,
1992)

[3] J. L. Picque and J. Pinard, J. Physics B 9, L77 (1976); P. T. H. Fisk et
al., Phys.

Rev. A 33, 2418 (1986); F. C. Spano, J. Chem. Phys. 114, 276 (2001)

[4] J. Qi et al., Phys. Rev. Lett. 83, 288 (1999); R. Garcia-Fernandez et al.,
Phys. Rev.

A 71, 023401 (2005)

[5] T. Kirova, et al., in: Proceedings of the XIV National Conference "Laser
Physics-

2007", (Ashtarak, Armenia, 2008) in print

[6] M. Auzinsh et al., Opt. Commun. 264, 333 (2006)

CP 166

188

Ladder and Lambda systems electromagnetically induced transparency in

thin and extremely-thin cells

A. Sargsyan1, M.G.Bason2, D. Sarkisyan1, Y. Pashayan-Leroy1,3, A.K.Mohapatra2,

C. S. Adams2

1Institute for Physical Research, NAS of Armenia, Ashtarak-0203, Armenia

2Department of Physics, Durham University, Durham DH1 3LE, United Kingdom

3Laboratoire de Physique de lUniversité de Bourgogne, Dijon, France

The recent interest in the effect of electromagnetically induced transparency
(EIT)

phenomenon is caused by a number of important applications. We study the
possibility

for miniaturization of alkali cells for application in the EIT experiments
without

compromising the EIT resonance parameters [1].

We present results on an EIT ladder system of the 85Rb, 87Rb, 5S-5P-nD(mS)

transitions with n = 5 as well as involving highly excited Rydberg states with n
= 26

and m = 48. For this purpose a recently developed multi-region (MR) high
temperature

cell containing Rb vapor has been used. The construction of MR cell allows us to
study

EIT effect in atomic vapor of thickness L= 4 mm, 2 mm, and 0.5 - 6 μm. The
design of

MR cells with length L in the range of 30 nm - 10 mm will be presented. It is

demonstrated that in 4 mm and 2 mm-long cells it is possible to realize a robust

formation of EIT resonance in counter-propagating geometry [2] with a high
contrast

(50 - 60%) and with a sub-natural linewidth. The fine structure of 26 D5/3, 3/2
has been

measured. For 5S-5P-48S system a pronounced Stark broadening of the EIT
resonance

is observed. The short thickness of the cell allows one to provide a tight
focusing to

achieve high intensity. Under this condition efficient 2-photon absorption has
been

detected, even when the thickness L is reduced to 6 μm.

We present experimental and theoretical results on an EIT ladder system of the

85Rb, 87Rb, 5S-5P-5D for a pure Rb vapour column with L of the order of light

wavelength (λ =780 nm) and varying in the range of (0.75 to 6) λ. It is shown
that in the

case when coupling laser frequency is resonant with atomic transition the
linewidth of

the EIT resonance (6 to 8 MHz) is weakly dependent on the thickness as ~ L-0.25.
The

explanation is that the contribution of atoms with small velocity projection in
the laser

radiation direction (i.e. atoms flying nearly parallel to the cell windows) is
enhanced

thanks to their longer interaction time with laser field [1]. Due to this atomic
velocityselectivity,

the observed linewidth of the EIT resonance is more than by an order

narrower than that expected from the inverse of the window-to-window flight time
of

the atoms. Meanwhile, direct influence of atom-wall collisions on the EIT
resonance is

well seen when there is a large detuning of the coupling laser with respect to
resonance

transition (EIT linewidth for this case achieves ~100 MHz). The slight
dependence of

the EIT linewidth for the case when coupling frequency is resonant with atomic

transition allows us to detect EIT resonance (<20 MHz) at the smallest thickness

reported up to now L= 0.75 λ = 585 nm.

References

[1] Y. Pashayan-Leroy, C. Leroy, A. Sargsyan, et. al., JOSA B, 24, 1829 (2007).

[2] A. K. Mohapatra, T. R. Jackson, C. S. Adams, Phys. Rev. Lett. 98, 113003
(2007)

CP 167

189

Saturation effects of Faraday rotation signals in Cs vapor nanocells:

thickness-dependent effects

A. Sargsyan1, D. Sarkisyan1, A.Papoyan1,Y. Pashayan-Leroy1,2, C.Leroy2,

P. Moroshkin3 and A. Weis3

1Institute for Physical Research, NAS of Armenia, Ashtarak-2, 378410, Armenia

2Laboratoire de Physique de lUniversité de Bourgogne, CNRS-UMR 5027, Dijon,
France

3Départment de Physique, Université de Fribourg, 1700 Fribourg, Switzerland

Magneto-optical effects, in particular the nonlinear Faraday rotation (NFR),
have proven to

be powerful tools in the laser spectroscopy of atomic gases. Optical
magnetometers based

on ultra-narrow spectral features accompanied by a strong polarization rotation
are under

active development. Ordinary cm-sized alkali metal cells are basic elements of
such types

of optical magnetometers [1]. Recently, differences of the resonant absorption
and

fluorescence spectra on the D2 line (λ =852 nm) of Cs vapor were demonstrated
[2] when

exciting the transition either in a cell of L=λ/2 thicknesses and a L=λ cell.

Here we present experimental and theoretical results of NFR signals for
thicknesses

L=λ/2 and L=λ performed on the D1 line λ =894 nm of Cs vapor. The nanocell was
placed

inside Helmholtz coils and a crossed polarizer geometry was used. The beam of a

frequency-tunable DFB diode laser (λ = 894 nm, spectral width γL ~ 6 MHz)
irradiated the

nanocell under an angle close to the normal in resonance with the D1 line of Cs.
Signals

recorded with different laser intensities were compared. The magnetic field B
was applied

along the laser propagation direction and could be varied in the range of 1-20
G. Spectra of

the NFR signal and absorption spectra for L=λ/2 and L=λ were compared.

There are two main features: i) significant differences were observed between
the

NFR signal at L=λ/2 (~450 nm) and at L= λ. In the L=λ/2 cell, the Dicke-narrowed

absorption profile causes a stronger nonlinear Faraday rotation than in the L= λ
(while in an

ordinary cm-sized cell a length increase leads to increase of the NFR signal),
accompanied

by a significant spectral narrowing down to 20 MHz. ii) at relatively high
intensities (>10

mW/cm2) the spectrum of the NFR signal for L= λ /2 simply broadens, while for L=
λ, the

NFR signal vanishes completely due to strong optical-pumping. The different
behaviors for

L= λ /2 and L= λ is more pronounced in the NFR signals than in the absorption
spectra. A

theoretical model taking optical pumping effects into account gives a good
agreement with

the experiment.

A simple magnetometer based on the NFR signal in a nanocell with L= λ/2 could be

developed. A sensitivity of several tens of mG is expected together with a
spatial resolution

in the nanometer range was achieved. This may prove useful for measurements of
strongly

inhomogeneous magnetic fields.

References

[1] D.Budker, W.Gawlik, D.Kimball, S.Rochester, V.Yaschuk, A.Wies, Rev. Mod.
Phys.

74, 1153 (2002) and reference therein.

[2] C. Andreeva, S. Cartaleva, L. Petrov, S. M. Saltiel, D. Sarkisyan, T.
Varzhapetyan, D.

Bloch, M. Ducloy, Phys. Rev. A 76, 013837 (2007) and reference therein.

CP 168

190

Magneto-optical resonances in atomic rubidium at

D1 excitation in ordinary and extremely thin cells

L. Kalvans1, M. Auzinsh1, R. Ferber1, F. Gahbauer1,

A. Jarmola1, A. Papoyan2, D. Sarkisyan2

1Laser Centre of the University of Latvia, 19 Rainis Boulevard, LV-1586, Riga,
Latvia

2Institute for Physical Research, NAS of Armenia, Astarak-0203, Armenia

We present the results of a detailed experimental and theoretical investigation
of nonlin-

ear magneto-optical resonances at D1 excitation of atomic rubidium in both
ordinary and

extremely thin vapor cells. These sub-natural linewidth resonances have been
known for

some time [1,2] and continue to be the subject of intriguing investigations and
a valuable

tool for ne-tuning theoretical models [3]. In this work, magneto-optical
resonances are

observed in both cells and can be bright or dark, depending on which hyper ne
transition

is excited. However, in a normal cell individual hyper ne transitions cannot be
resolved

because of Doppler brodening. The use of extremely thin cells (ETCs) represents
a rather

new experimental technique and allows the experimenter to realize direct
sub-Doppler

spectroscopy [4]. The thickness of the cell L used in this study varies in the
range from

150 nm to 1600 nm. By comparing results obtained from both cells, one obtains
use-

ful information about how Doppler broadening in uences the shape and contrast of
the

resonances.

In this study experimental results from an ordinary Rb vapor cell and an ETC
lled

with Rb are compared to theoretical calculations based on the optical Bloch
equations,

which have proven to be well suited to describe the signals obtained in ordinary
vapor

cells [3]. The vapor cells were placed inside a three-axis Helmholtz coil system
and excited

with a diode laser manufactured by Toptica, GmbH. The polarization of the
exciting laser

radiation was perpendicular to the magnetic eld, which was scanned, and the
uorescence

was observed in the direction along the magnetic eld. In order to test how well
our model

can describe ETC behavior, we study resonances at di erent laser powers, beam
cross-

sections, and wall separations L, and compare the experimental measurements with
the

results of calculations based on the model. By requiring the model to take into
account

so many di erent parameters, it will be possible to either validate the model as
is for

the case of the ETC or to identify new e ects that should be taken into account
when

modelling the signals obtained with ETCs.

We acknowledge support from the Latvian National Research Programme in Material

Sciences Grant No. 1-23/50, the University of Latvia grant Y2-ZP04-100, the ERAF
grant

VPD1/ERAF/CFLA/05/APK/2.5.1./000035/018, and the INTAS projects 06-1000017-

9001 and 06-1000024-9075. A. J., F. G., and L. K. acknowledge support from the
ESF

project.

References

[1] R. W. Schmieder et al., Phys. Rev. A 2, 1216 (1970)

[2] G. Alzetta, A. Gozzini, L. Moi, and G. Orriols, Il Nuovo Cimento B 36, 5
(1976)

[3] M. Auzinsh et al., arXiv:0803.0201v1 [physics.atom-ph]

[4] D. Sarkisyan, D. Bloch, A. Papoyan, and M. Ducloy, Opt. commun. 200, 201
(2001)

CP 169

191

Frequency-modulation spectroscopy of coherent

population trapping resonances

A.Yu. Samokotin1, A.V. Akimov1, N.N. Kolachevsky1, Yu.V. Vladimirova2,

V.N. Zadkov2, A.V. Sokolov1, V.N. Sorokin1

1P. N. Lebedev Physical Institute,

Leninsky pr., 53, 119991 Moscow, Russia

2International Laser Center and Faculty of Physics,

M.V. Lomonosov Moscow State University,

199899 Moscow, Russia

E-mail: samokotin@gmail.com

Resonance of coherent population trapping (CPT) is one of nonlinear effects in
three-level

atomic systems in so-called Λ-configuration. The resonance appears when a
bichromatic

optical field with certain frequency and phase correlations between its
components is

applied to the system. The ultimate spectral width of the CPT resonance is
determined

by the coherency time between the lower levels of the Λ-system and can amount to
several

tens of hertzs. A high Q-factor of CPT resonances enables to use them as
frequency

references and in magnetometry.

One of the simplest experimental methods to create two phase-correlated light
fields is a

frequency modulation (FM) of a monochromatic light field. In the case of diode
laser, the

FM of light is achieved via modulation of the injection current.

In this work we experimentally investigated CPT resonances on Zeeman sublevels
of 87Rb

D1-line excited by FM-modulated laser field and considered possible applications
to magnetometry.

The laser was tuned to F = 2 → F = 1 transition, such that a chain of three

Λ-systems can be excited by the sidebands of the field. The FM field contains a
number

of harmonics which relative amplitudes depend on modulation parameters, and thus
a

number of CPT resonances of different amplitudes are excited at corresponding
frequencies.

The experimental results are confirmed by the recent theoretical consideration
of

FM spectroscopy of CPT resonances [1,2].

Since the frequency of the CPT resonance depends on magnetic field, the FM
spectroscopy

allows to measure magnetic field applied to the Rb vapors. We recorded a number
of CPT

resonances in two Rb cells (with and without buffer gas) at different values of
an external

magnetic field. Our experimental setup allows to measure magnetic fields in the
range

10-100 G with 0.05% accuracy. Non-linear Zeeman effect, playing a significant
role in

such fields, is studied in details.

References

[1] J. Vladimirova et al., Laser Physics Lett., 3(9), 427-436 (2006).

[2] Yu.V. Vladimirova et al., J. of Theor. and Exp. Phys., 96, 629 (2003).

CP 170

192

Pump-probe spectroscopy:

a survey of the spectra for four polarization

combinations in degenerate two-level atoms

K. Dahl, L. Spani Molella, R.-H. Rinkleff, and K. Danzmann

Albert-Einstein-Institut, Max-Planck-Institut f¨ur Gravitationsphysik and

Institut f¨ur Gravitationsphysik, Leibniz Universit¨at Hannover

Callinstrasse 38, D-30167 Hannover, Germany

E-mail: rolf-hermann.rinkleff@aei.mpg.de

The optical properties of a cesium atomic beam driven on a resonant hyperfine
transition

in the D2 line were experimentally investigated as a function of the probe-laser
frequency.

In the present experiment the coupling laser drove the hyperfine transition 6s
2S1/2, F=4

6p 2P3/2, F=5 and was actively locked to it by means of frequency modulation
spectroscopy.

The probe-laser frequency was scanned around the same transition [1]. The

coupling and probe absorption spectra were measured also in a range of
probe-laser intensities

large enough to affect the pump-laser absorption. We present an experimental

survey of the coupling and probe absorption spectra for four polarization
combinations

( +, , − , − +).

For all polarization combinations the probe-laser absorption profiles showed
electromagnetically

induced absorption (EIA), a spectrum characterized by a peak on the ordinary

absorption profile. The observed coupling-laser absorption profiles could be
described by

absorption within transparency, i.e. the absorption in the region around the
two-photon

resonance was smaller than the absorption corresponding to the one-photon
transition induced

by the coupling laser, and at the two-photon resonance an extra absorption peak

on this curve was measured.

For investigations with laser beams of counterrotating circular polarizations (
− +) the

coupling-laser absorption profiles showed at various laser powers a surprising
behavior as

function of the laser powers. We detected a transition of the two-photon
resonance peak

from absorption to more transparency when the probe-laser exceeded the
constantly held

coupling-laser power [2]. Furthermore, a switch was observed for a constant
probe-laser

power when varying the coupling-laser power. In all these cases the probe-laser
absorption

profiles showed EIA signals. These findings are the experimental confirmation of

published theoretical predictions [3]. However, for phase measurements, no
corresponding

switch from positive to negative parametric dispersion or from negative to
positive

dispersion was observed.

The work was supported by the grant SFB407 of the Deutsche
Forschungsgemeinschaft.

References

[1] L. Spani Molella, R.-H. Rinkleff, K. Danzmann, Appl. Phys. B 90, 273 (2008)

[2] K. Dahl, L. Spani Molella, R.-H. Rinkleff, K. Danzmann, Optics Letters (in
press)(2008)

[3] C. Goren, A. D. Wilson-Gordon, M. Rosenbluh, H. Friedman, Phys. Rev. A 69,
053818

(2004)

CP 171

193

Dark resonance narrowing

in uncoated rubidium vacuum vapor cell

Z. Grujiśc, M. Mijailoviśc, D. Arsenoviśc, M. Radonjiśc and B. M. Jelenkoviśc

Institute of Physics

Pregrevica 118, Belgrade-Zemun, Serbia

E-mail: zoran.grujic@phy.bg.ac.yu

The CPT (Coherent Population Trapping) phenomena has been intensely investigated
due

to its narrow resonance suitable for precision measurements, magnetometry and
atomic

clocks etc. DiŽerent approaches were applied in order to make these resonances
narrower

in alkali vapor cells: coated cells in order to preserve atomic coherence after
collision with

the cell wall, use of buŽer gas cells to increase atom time of °ight through
laser beam,

and nanocells.

In our experiment we use spatially separated pump and probe laser beams in order
to

induce Ramsey type CPT narrowing [1]. The probe laser beam (diameter of 1.5 mm)
is

placed in the center of pump beam which has a ring like pro¯le. Outside diameter
of the

pump laser beam is very close to the Rb cell diameter of 25 mm, while its inner
is larger

then the probe laser diameter. Booth pump and probe laser beams are obtained
from a

single ECDL (External Cavity Diode Laser), locked to the Fg = 2 ! Fe = 1
transition at

D1 line of 87Rb. Thus, some Rb atoms are ¯rst pumped into the dark state by the
pump

laser beam, then travel through the \dark region" between the pump and the probe
beam

before they reach the pump laser beam. The dark state and induced Zeeman
coherences

created by pump are experimentally detected in the probe beam absorption.
Related work

has been published by A. S. Zibrov and A. B. Matsko [2]. Obtained narrow
resonances

widths, shapes depend of "dark region" length and pump and the probe laser
intensities.

Our theoretical model relays on solving time-dependent optical Bloch equations
and takes

into account diŽerent atomic velocities and angles of atom propagation in
respect to the

laser beams. It is shown that experiment and theory are in a good agreement for
diŽerent

probe and pump beam polarizations and intensities.

References

[1] Z.D. Grujiśc, M.M. Mijailoviśc, B.M. Paniśc, M. Miniśc, A.G. Kovaˇceviśc, M.
Obradoviśc,

B.M. Jelenkoviśc and S. Cartaleva, Acta Physica Polonica A, No 5, 112, 799
(2007).

[2] A. S. Zibrov and A. B. Matsko, Physical Review A, 112, 013814

CP 172

194

Quantum search with trapped ions

S. Ivanov, P. Ivanov and N. Vitanov

Department of Physics, So¯a University, James Bourchier 5 blvd, 1164 So¯a,
Bulgaria

We propose an ion trap implementation of Grover's quantum search algorithm for
an

unstructured database of arbitrary length N. The experimental implementation is
ap-

pealingly simple because the linear ion trap allows for a straightforward
construction, in a

single interaction step and without a multitude of Hadamard transforms, of the
re°ection

operator, which is the engine of the Grover algorithm. Consequently, a dramatic
reduc-

tion in the number of the required physical steps takes place, to just O(

p

N), the same

as the number of the mathematical steps. The proposed setup allows for
demonstration

of both the original (probabilistic) Grover search and its deterministic
variation, and is

remarkably robust to imperfections in the register initialization.

CP 173

195

The observability of atoms

Gebhard von Oppen

Institut f¨ur Optik und Atomare Physik, Technische Universit¨at Berlin

Atomic particles differ fundamentally from macroscopic objects. In every
measurement

with moderate spatial resolution, macroscopic objects can be observed
continuously. Free

atoms, however, are observed discontinuously. Their observation is based on
discrete,

spontaneously occurring elementary events, which can be counted. During free
flight,

atoms are principally unobservable. As a consequence, identical atomic particles
are

indistinguishable, whereas macroscopic twin-bodies can be distinguished [1, 2].

In this contribution Ill show you that the difference in observability provides
the key

for an experimentally oriented understanding of the spooky phenomena of
quantum

dynamics and of the appearance of chance in physics. In particular, Ill
consider:

1. The presence of statistical and thermal noise in all measurements: Noise is
neglected in

classical dynamics (mechanics and electrodynamics), but justifies the concept of
chance

in statistical thermodynamics. Accordingly, classical dynamics describes only
reversible

processes, whereas statistical thermodynamics also applies to irreversible
processes.

2. The transition from quantum to classical physics: Quantum dynamics is not a
generalization

of classical dynamics, but describes an idealization of nature opposite to the

ideal of classical dynamics. The two theories apply to opposite extremes on a
scale of

observability [2].

3. Space-time reality: ...we have to abandon the description of atomic events
as happenings

in space and time (Einstein, Infeld: The evolution of physics). A description

in space and time is only justified for objects, which can be observed
continuously, but

not for atomic particles. Therefore, atoms must not be idealized as mass-points,
and a

thermodynamic ensemble of free atoms is fundamentally different from the
mechanical

model of the ideal gas [3].

4. The approaches of physics to nature: The objects of physics must be
observable.

Otherwise they cannot be investigated experimentally. For being observable, the
objects

must be coupled spontaneously to the environment. This spontaneous coupling
prohibits

an exact reproducibility of experiments. As a consequence of this insufficiency
on the

experimental side, theory cannot image nature exactly, but describes
idealizations of

nature. Presently, physics is based on three idealizations: Classical dynamics,
statistical

physics and quantum dynamics.

5. From decomposition to isolation: The objects of classical dynamics can be
decomposed.

But by decomposing, one produces components, which are not any more observable
continuously.

One ultimately obtains the isolated objects of quantum dynamics[1].

References:

[1] G. v. Oppen, Physics Uspekhi 39, 617 (1996)

[2] G. von Oppen, Eur. Phys. J. Special Topics 144, 3 (2007)

[3] Bergmann, Schaefer, Lehrbuch der Experimentalphysik, Band 1 (12. Auflage,
2009),

in print

CP 174

196

Characterization of a High Precision Cold Atom

Gyroscope

T. Leveque, A. Gauguet, W. Chaibi and A. Landragin

LNE-SYRTE, CNRS UMR 3630, Observatoire de Paris

61 avenue de l'Observatoire, 75014 Paris, France

E-mail : thomas.leveque@obspm.fr

We investigate the limits of our inertial sensor using a cold atom
interferometer. In

contrast with previous atomic setups, emphasis was placed on the long term
stability and

compactness of the device thanks to the use of laser cooled atoms. Moreover it
has been

designed to give access to all six axes of inertia (three accelerations and
three rotations)

[1]. The expected improvement in stability will enable to consider applications
in inertial

navigation, geophysics and tests of general relativity.

Caesium atoms are loaded from a vapour into two independent magneto-optical
traps for

140 ms. Two caesium clouds are then launched into two opposite parabolic
trajectories

using moving molasses at 2.4 m:s1, with an angle of 8 with respect to the
vertical

direction. At the apex of their trajectory, the atoms interact successively with
three

Raman laser pulses, which act on the matter-wave as beam splitters or mirrors,
and

generate an interferometer of 80 ms total interaction time. The use of two
atomic sources

allows discrimination between the acceleration and rotation.

The sensitivity to acceleration is 5; 5 107m:s2 at one second, limited by
residual

vibration on our isolation platform. Concerning the rotation, the sensitivity is
2; 3

107rad:s1 at one second, limited by the quantum projection noise in the
detection. After

1000 seconds of integration time, we achieve a sensitivity of 1 108rad:s1.
Moreover,

we have performed studies of all possible sources of drift on the rotation
signal. Among

others, we measured the e ect of the two photon light shift during the Raman
laser pulses.

We also identi ed the main limit of the stability, which is linked to uctuations
of the

atomic trajectories inducing Raman laser wave-front changes.

We characterize the accuracy of our gyroscope in term of bias and scaling
factor. In

this purpose, we record rotation phase shift as a function of the interrogation
time and

rotation rate. The rotation shift behaves as the square of the interrogation
time and

linearly with the projection of the Earth's rotation rate, which is modulated by
turning

the interferometer in the horizontal plane. The linearity of our sensor was
demonstrated

with an agreement better than 0.01% and the bias was determined with an accuracy
of

5 108rad:s1. Currently, we are developing a new method to enable
measurements in

noisy environments which will be crucial for applications in the eld of inertial
navigation.

References

[1] B. Canuel, F. Leduc, D. Holleville, A. Gauguet, J. Fils, A. Virdis, A.
Clairon, N.

Dimarcq, Ch.J. Bord e, and A. Landragin, "Six-Axis Inertial Sensor Using
Cold-Atom

Interferometry", Phys. Rev. Lett. 97 010402 , 2006.

CP 175

197

CP 176

198

CP 177

199

Parametrization of NeI spectrum for 2p55g, 6g, 7g

configurations using semiempirical method

Anisimova G.P.1, Efremova E.A.1, Tsygankova G.A.1

1St.-Petersburg State University

Petergof, Ulianovskaja st., 1, NIIF-SPbSU, St.-Petersburg, 198504, Russia.

E-mail: efremovakat@inbox.ru

The paper presents results of numerical study of the fine structure parameters
(the radial

integrals in the energy operator matrix) for 2p55g, 2p56g and 2p57g
configurations of a

neutral Neon atom. The angle coefficients for the radial integrals were obtained
taking

into account the following interactions in the Breits Hamiltonian:
electrostatic, spin-orbit

(own and foreign), spin-spin and orbit-orbit [1].

The energy operator matrix for "hole" configurations can be calculated either
using fractional

parentage coefficients or via free momentums representation. In the latter case
it is

assumed that the atoms state is described exclusively by the individual quantum
numbers

of particular electrons. The energy operator matrix obtained via free momentum
representation

was transformed to LSJM and j1KJMrepresentations. For vector types

of coupling the energy operator matrix has 24 matrix elements each of which is a
linear

combination of 18 fine structure parameters.

The calculations are based on the empirical data namely the energies of the fine
structure

experimentally obtained with the high precision [2; 3].

The classification of the fine structure levels for 2p55g, 2p56g and 2p57g of
NeI was given

in jK-coupling representation. The calculation of the parameters is also
accomplished

using the energy operator matrix given in jK-coupling representation. The
numerical

calculation is based on the Newtons method applied to the set of non-linear
equations.

The unknowns for the equations were the parameters of the fine structure as well
as the

expansion coefficients of wave functions in jK-coupling basis. The initial
approximation

for Newtons method was derived using least-squares method.

As a result of numerical study a set of the fine structure parameters was
obtained. Substitution

of these parameters into the energy operator matrix and follow-up
diagonalization

for all the coupling types yields the energies, which fully agree with the
energies obtained

experimentally. Expansion coefficients for LS and JK basises, gyromagnetic
ratio

and level compositions in LSbasis were also obtained. It can be concluded that
the

highly-excited 2p55g, 2p56g and 2p57g configurations of NeI are close to
jK-coupling

model.

References

[1] Anisimova G.P., Efremova E.A., Tsygankova G.A., Vestnik of St.-Petersburg
State

University. Series 4. Part 3., 49 (2007)

[2] Chang E.S., Schoenfeed W.G., Biemont E., Quinet P., Palmeri P., Phys. Scr.
V. 49.,

26 (1994)

[3] Saloman E.B., Sansonetti C.J. Wavelengths, J. Phys. Chem. Ref. data. V. 33.
N 4,

1113 (2004).

CP 178

200

Ab initio calculations of aluminium-like calcium

R. Karpu skien_e, P. Bogdanovich and O. Rancova

Institute of Theoretical Physics and Astronomy of Vilnius University

A. Go stauto st. 12, 01108 Vilnius, Lithuania

E-mail: olga@itpa.lt

This work presents theoretical investigation of Ca VIII ion of aluminium
isoelectronic

sequence. The ab initio study of Ca VIII was performed within the con guration
interac-

tion approximation in the basis of transformed radial orbitals with a variable
parameter

[1]. Relativistic e ects were accounted for within the Breit-Pauli
approximation.

The ground con guration 3s23p and excited con gurations 3s3p2, 3s23d, 3p3,
3s3p3d,

3s24s, 3s24p, 3s24d, 3s24f, 3s3p4s and 3s3p4p are studied. The rst calculation
of energy

spectra was performed in the basis of admixed con gurations made by virtual
excitations

from 3l- and 4l-shells. The second calculation was performed in the extended
basis of

admixed con gurations made by the virtual excitations not only from 3l- and 4l-
shells,

but also from the closed shells 2s- and 2p-. This way enables us to take into
account core

polarization e ects.

The obtained energy spectra of ground con guration 3s23p and excited con
gurations

3s3p2, 3s23d, 3p3 and 3s3p3d were compared with available data [2-3]. We
supplement

our results with the energy spectra of highly excited con gurations 3s24s,
3s24p, 3s24d,

3s24f, 3s3p4s and 3s3p4p as well. The obtained energy levels of these con
gurations

(except 3s24p and 3s3p4p) are compared with data from [4].

The comparison of the obtained results and the data presented by other authors
show

that the core polarization is important and has a considerable in uence on the
accuracy

of theoretical energy spectra.

The multicon guration wave functions determined as a result of the energy matrix
diag-

onalization were used to calculate the wavelengths and the characteristics for
the electric

dipole transitions from the excited con gurations. The radiative lifetimes of
the excited

levels were also calculated and compared with the available data.

These calculations have been performed using the resources of the European
Commission

project RI026715 BalticGrid and LitGrid project.

References

[1] P.Bogdanovich, R. Karpu skien_e, Lith. J. Phys. 39, 193 (1999)

[2] E. Landi, P.J. Storey, C.J. Zeippen, Astrophys. J. 607, 640 (2004)

[3] U.I. Safronova et al, Atomic Data and Nuclear Data Tables 84, 1 (2003)

[4] J. Sugar, C. Corliss, J. Phys. Chem. Ref. Data 14, Suppl. 2, 1 (1985)

CP 179

201

Isotope shifts of forbidden lines of Lead

T.J. W¸asowicz, S. Werbowy, R. Drozdowski, J. Kwela

Institute of Experimental Physics, University of Gdansk, ul. Wita Stwosza 57,

80-952 Gdansk, Poland

The 6s26p2 ground configuration of Pb I gives rise to five levels 1S0, 3P2,1,0
and 1D2. In

the 6s26p ground configuration of Pb II only two levels 2P1/2 and 2P3/2 appear.
Since

electric-dipole (E1) transitions between the states of the same parity are
forbidden, all

the levels of these configurations are metastable. In the second-order radiation
theory

weak magnetic-dipole (M1), electric-quadrupole (E2) or mixed type (M1+E2)
transitions

between these levels are permitted.

In the experiment the isotope shifts (IS) of forbidden lines 461.9 nm (6p2 1S0 →
6p2 3P1;

M1), 531.5 nm (6p2 1S0 → 6p2 3P2; E2), 733.2 nm (6p2 1D2 → 6p2 3P1; M1+E2) of Pb
I

and 710.2 nm (6p 2P3/2 → 6p 2P1/2; M1+E2) of Pb II between four stable isotopes
(204,

206, 207, 208) were measured. The observation of isotopic structure of multipole
lines

is very difficult because of relatively small shifts (see Table 1) and the
components of

the isotope structure are partly or completely unresolved. For such a case the
computer

simulation technique becomes very useful. Such a computer technique has been
recently

used by us in the analysis of the IS spectra of electric-dipole (E1) lines of Pb
I [1] and Pb II

[2]. By variation of free parameters describing the line shape and positions of
individual

components the calculated profiles were fitted into the recorded spectra. In the
case of the

M1+E2 transitions the E2 admixtures (see e.g. [3]) were also taken into account
as a fixed

parameter. Moreover, using the King plots we were able to separate the two
contributions

to the total isotope shift, namely the mass and the field shifts. These results
may prove

to be useful for future studies of PNC in Pb.

Table 1: Measured isotope shifts relative to the 208 isotope of lead (in mK).

Line (nm) Transition δν207CG,A

i δν206,A

i δν204,A

i

461.9 6p2 1S0→6p2 3P1 4.9 (1.1) 7.8 (1.3) 14.6 (3.4)

531.5 6p2 1S0→6p2 3P2 8.1 (1.5) 13.0 (1.2) 24.2 (5.4)

733.2 6p2 1D2→6p2 3P1 5.6 (0.6) 8.8 (1.0) 16.3 (2.4)

710.2 6p 2P3/2→6p 2P1/2 10.8 (1.9) 17.3 (2.3) 32.7 (5.6)

Acknowledgment

This work was supported by the University of Gdansk, grant BW 5200-5-0053-8.

References

[1] T.J. W¸asowicz, J. Kwela, Phys. Scr. 77, 025301 (2008)

[2] T.J. W¸asowicz, R. Drozdowski, J. Kwela, Eur. Phys. J. D 36, 249 (2005)

[3] T.J. W¸asowicz, Phys. Scr. 76, 294 (2007)

CP 180

202

Solid 4He stabilized by charged impurities below the

solidi¯cation pressure of pure helium

P. Moroshkin, V. Lebedev, A. Weis

University of Fribourg, Department of Physics, Fribourg, Switzerland

The coexistence of a 4He crystal with super°uid 4He is a model system for
investigating

fundamental aspects of the growth and melting of crystals. Here we present a
study of

a dramatic eŽect [1] that occurs during the melting of solid 4He doped with
nanoscopic

impurities | alkali atoms, clusters, ions, and electrons: the doped part of the
crystal

remains solid under conditions at which pure helium is liquid. We refer to this
structure

as an iceberg. If the structure disintegrates in a static electric ¯eld of
several kV/cm

fragments of the iceberg containing unequal amounts of electrons and positive
ions move

towards either the positive or the negative electrode. These events are
accompanied by

electric current pulses that have allowed us to determine the number density of
charged

particles in the sample to be of order of 1014 ¡ 1015 cm¡3. We consider the
iceberg as

being an aggregation of positively charged particles (snowballs) and electron
bubbles.

Using interferometry we have found [1] that the density of the solid structure
(iceberg)

lies between the densities of pure liquid and pure solid helium. On the other
hand,

a comparison of laser-induced °uorescence spectra of neutral Cs atoms trapped in
the

iceberg with those in bulk solid 4He indicates that the iceberg has the same
density and

crystalline structure (bcc, hcp) as the bulk solid 4He. We therefore suggest
that the

iceberg is in fact a porous structure ¯lled with liquid helium.

[1] P. Moroshkin, A. Hofer, S. Ulzega, A. Weis, Nature Physics 3, 786 (2007).

CP 181

203

Spectroscopy of Ba atoms isolated in solid He matrix

P. Moroshkin, V. Lebedev, A. Weis

University of Fribourg, Department of Physics, Fribourg, Switzerland

We present the results of a new spectroscopic study of Ba-doped solid 4He. Ba
atoms

are introduced into the solid He matrix by means of laser ablation from a
metallic target

surrounded by solid He. This allows us to produce a sample with up to 1015 Ba
atoms per

cm3. By exciting the sample with a pulsed-laser tuned over 440 { 690 nm we have
found

a number of °uorescence lines, some of which were not detected in earlier
studies [1,2].

Our analysis shows that the Ba atoms are excited at the single-photon 6s2 1S0
¡6s6p1P1

transition at 540 nm and at least at 6 diŽerent two-photon transitions at 530,
568, 618,

632, 650, and 675 nm. The decay of highly excited states populated by the
two-photon

transitions proceeds via a cascade of °uorescence transitions including
triplet-triplet and

intercombination lines, as well as other so far unidenti¯ed lines.

We have also performed a systematic study of the absorption and °uorescence
spectra

of the single-photon 6s2 1S0 ¡ 6s6p1P1 transition and their dependence on helium
pres-

sure. The spectral line is blueshifted and broadened by the interaction with the
matrix.

The shift and the broadening increase with the He pressure following the trend
already

observed in pressurized liquid helium.

[1] H. Bauer, M. Beau, D. Friedl, C. Marshand, K. Miltner, H. J. Reyher, Phys.
Lett. A

146, 134 (1990).

[2] S. I. Kanorsky, M. Arndt, R. Dziewior, A. Weis, T. W. HÄansch, Phys. Rev. B
49,

3645 (1994).

CP 182

204

New Measurement of the 2S Hyper¯ne Splitting in

Atomic Hydrogen

A. Matveev1;2, J. Alnis1, C. Parthey1, N. Kolachevsky1;2, T.W. HÄansch1;3

1 MPI fÄur Quantenoptik, Hans-Kopfermann Str. 1, 85748 Garching, Germany

2 P.N. Lebedev Physics Institute, Leninsky prosp. 53, 119991 Moscow, Russia

3 Ludwig-Maximilians University,Geschwister-Scholl-Platz 1, 80539 Munich,
Germany

Recent advances in laser stabilization, optical frequency measurements and
preparation of

cold atomic samples open possibility to compare optical frequencies to the 17th
decimal

place [1] which signi¯cantly overcomes the accuracy of the best Cs fountain
clocks de¯ning

the SI second [2]. Besides this impressive result there exist many other
examples when

spectroscopy in the optical domain allows for more accurate measurements than
classical

radio-frequency techniques.

In 2003 we have developed a new optical method for measuring the 2S hyper¯ne
split-

ting in atomic hydrogen by help of two-photon spectroscopy of the 1S { 2S
transition

[3]. By measuring the frequency diŽerence between two optical ¯elds at 243nm
driving

1S(F = 0) ! 2S(F = 0) and 1S(F = 1) ! 2S(F = 1) two-photon transitions in

a nearly-zero magnetic ¯eld one can derive the frequency of the 2S hyper¯ne
splitting

fhfs(2S). Accurate experimental value fhfs(2S) allows for accurate tests of
quantum

electrodynamics theory since the speci¯c diŽerence D21 = 8fhfs(2S) ¡ fhfs(1S)
can be

calculated with a high accuracy [4].

In 2008 we have remeasured the fhfs(2S) frequency using an ultra-stable
vibrationally-

and temperature-compensated optical cavity as an optical frequency reference
[5]. The

diode laser at 972nm locked to this cavity has a spectral line width of less
than 0.5 Hz

while its frequency drift is on the level of 50 mHz/s. The excellent stability
of this new

laser oscillator (the Allan deviation reaches 2 £ 10¡15 in less than 1 s) allows
for accurate

measurement of the 2S hyper¯ne splitting.

The two photon transitions between diŽerent hyper¯ne sublevels are excited by
the second

harmonic of a dye laser [3], while its frequency is continuously compared to the
frequency

of the second harmonic of the stabilized diode laser at 972 nm. The new
measurement

possesses a signi¯cantly improved statistics which, in turn, allows for more
detailed study

of systematic eŽects. The preliminary analysis of experimental data gives us a
value

of fhfs(2S) = 177 556 840(5) Hz which uncertainty is about 5 times less than the
most

accurate direct radio frequency measurement performed up to date [6].

[1] T. Rosenband et al., Science 319, 1808 (2008).

[2] S. Bize et al. J. Phys. B: At. Mol. Opt. Phys. 38 S44968, (2005).

[3] N. Kolachevsky, M. Fischer, S.G. Karshenboim, T.W. HÄansch, Phys. Rev. Lett.
92,

033003 (2004).

[4] S.G. Karshenboim and V.G. Ivanov, Phys. Lett. B 524, 259 (2002).

[5] J. Alnis, A. Matveev, N. Kolachevsky, Th. Udem, and T.W. HÄansch,
arxiv:0801.4199.

[6] N.E. Rothery and E.A. Hessels, Phys. Rev. A 61, 044501 (2000).

CP 183

205

High Resolution Laser Spectroscopy of Scandium

Yu.P. Gangrsky1, K.P. Marinova1, S.G. Zemlyanoi1, M. Avgoulea2, J.Billowes2,

P.Campbell2, B. Cheal2, B. TordoŽ2, M. Bissel3, D.H. Forest3, M. Gardner3, G.

Tungate3, J. Huikari4, H. Penttila4 and J. Aysto4

1FLNR Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region, Russia

2Shuster Building, University of Manchester, Manchester M13 9PL, UK

3School of Physics and Astronomy, University of Birmingham, B15 2TT, UK

4Accelerator Laboratory, University of Jyvaskyla SF-405 51, Finland

Collinear laser spectroscopy experiments on the ScII transition 3d4s3D2 ! 3d4p
3F3 at

¸ ¼ 363.1 nm were performed on the 42¡46Sc isotopic chain using an ion guide
isotope

separator with a cooler-buncher [1]. Hyper¯ne structure constants, nuclear
moments,

isotope and isomer shifts of ¯ve ground states and two isomers, 44;45Sc, were
measured.

Among the investigated nuclei the 45Sc isotope deserves closer attention because
along

with several other odd-A nuclei in the lower 1f7=2 shell it has a positive
parity isomeric

state with I¼ = 3/2+. Such excited states have been explained [2] in the
framework of the

Nilsson model: the Nilsson 3/2+ orbital of the sd shell and the lowest orbital
of the 1f7=2

shell approach each other for increasing deformation, thereby producing a
low-lying well

deformed core excited state. The value of Q0 obtained from the laser
spectroscopic data in

this work is nearly two times larger, than the one of [2]. The unusually large
quadrupole

moment of the isomeric state of 45Sc is the most striking feature of the present
data. This

surprising fact remains so far unexplained.

The preliminary analysis performed to date can only provide estimates of the
expected

upper and lower limits of the radii changes. No drastic contradiction with the
overall radii

trend in the f7=2 shell is found. While the odd-even staggering is reduced
compared with

Ca and Ti, it is consistent with that observed in K, the only other odd-Z
element studied

in this region. Although qualitative, the new information on Sc charge radii
changes

constitutes a valuable contribution to the systematic of nuclear charge radii in
the Ca

region.

1. Billowes J., Hyp. Int. 162 (2005) 63.

2. Styszen J. et al., Nucl. Phys. A 262 (1976) 317.

CP 184

206

CP 185

207

CP 186

208

VUV Spectroscopy of Xe IX

H.P. Garnir, ´ E. Bi´emont, S. Enzonga Yoca and P. Quinet

Institut de Physique Nucl´eaire, Atomique et Spectroscopie

Universit´e de Li`ege

Sart Tilman B15, B4000 LIEGE BELGIUM

hpgarnir@ulg.ac.be

The spectrum of xenon ions has been recorded by the beam-foil method in the
10-110 nm

wavelength range and many lines of Xe VII-VIII have been analysed [1]. In our
spectra,

we have looked for lines belonging to 8 times ionized Xe. Some of the lines
attributed to

Xe IX have been pinpointed by a careful analysis of the line intensity variation
with the

beam energy [2]. For those lines, the lifetimes of the upper level have been
measured by

analyzing beam-foil decay curves (one of the rare methods able to provide
experimental

data in these multicharged ions).

Our measurements will be compared with theoretical values calculated by a
relativis-

tic Hartree-Fock approach including core-polarization effects and by a purely
relativistic

multiconfiguration Dirac-Fock method.

During the meeting, we will describe our experiment and present our new results.

References

[1] ´ E. Bi´emont, M. Clar, V. Fivet, H.-P. Garnir, P. Palmeri, P. Quinet, and
D. Rostohar,

Eur. Phys. J. D 44, 23 (2007)

[2] H.P. Garnir, Journal of Physics: Conference Series, accepted for publication

CP 187

209

Improved atomic data for platinum group elements

V. Fivet1, ´E. Bi´emont1,2, P. Palmeri1, P. Quinet1,2, L. Engstr¨om3, H.
Lundberg3

and H. Nilsson4

1 Astrophysique et Spectroscopie, Universit´e de Mons-Hainaut, B-7000 Mons,
Belgium

2 IPNAS, Universit´e de Li`ege, Sart Tilman, B-4000 Li`ege, Belgium

3 Department of Physics, Lund Institute of Technology, PO Box 118,

SE-22100 Lund, Sweden

4 Lund Observatory, Lund University, PO Box 43, SE-22100 Lund, Sweden

E-mail: vanessa.fivet@umh.ac.be

The spectra of the elements situated in the sixth row of the periodic table
(72<Z<86) are

still poorly known due to the lack of laboratory analysis and to the complexity
of their

electronic configurations of the type 4f145dNnl and 4f145dN−1nln0l0 (N=3−10, nl,
n0l0=6s,

6p, 6d, ...).

The aim of the present work is to provide a large amount of new atomic data for
neutral

and lowly ionized sixth row elements. The astrophysicists need these accurate
data for

refining their models in nucleosynthesis, for determining the chemical
composition of CP

stars, for the diagnostic of plasmas and for cosmochronology. Radiative
parameters for

some of these elements are also strongly needed for research oriented toward
controlled

thermonuclear fusion.

In the present work, radiative lifetimes of selected sixth row ions have been
measured

using TR-LIF spectroscopy[1] developed at the Lund Laser Centre by Prof.
Svanberg and

his group. The new results have been used to assess the accuracy of calculations
performed

with a Hartree-Fock-plus-Relativistic-corrections model that takes configuration

interaction and core-polarization effects into account[2,3].

By combining experimental lifetimes and theoretical branching fractions, we have
determined

new oscillator strengths and transition probabilities. We will discuss the
results

obtained for the following ions: Ta III (Z=73), W II, W III (Z=74) et Pt II (Z=
78).

These results will be stored in the database DESIRE (DatabasE on SIxth Row
Elements)

[4,5] on a website of the University of Mons-Hainaut.

References

[1] H.L. Xu , A. Persson, S. Svanberg, K.B. Blagoev, G. Malcheva, V. Penchev and
´E.

Bi´emont, Phys. Rev. A 70, 0425058 (2004)

[2] R.D. Cowan, The Theory of Atomic Structure and Spectra, University of
California

Press, Berkeley (1981)

[3] P. Quinet, P. Palmeri, ´E. Bi´emont, M.M. McCurdy, G. Rieger, E.H.
Pinnington, M.E.

Wickliffe and J.E. Lawler, Mon. Not. R. Astron. Soc. 307, 934 (1999)

[4] V. Fivet, P. Quinet, P. Palmeri, ´E. Bi´emont and H.L. Xu, J. Electron.
Spectrosc.

Relat. Phenom. 156-158, 250 (2007)

[5] http:\\www.umh.ac.be\ astro\desire.shtml

CP 188

210

Impact of high-order moments on the statistical

modeling of transition arrays

F. Gilleron1, J.C. Pain1, J. Bauche2 and C. Bauche-Arnoult2

1Commissariat a l'Energie Atomique, Centre DAM ^Ile-de-France, Bruy
eres-le-Ch^atel,

91297 Arpajon Cedex, France

2Laboratoire Aim e Cotton, CNRS II, B^atiment 505, 91405 Orsay, France

The impact of high-order moments on the statistical modeling of transition
arrays in

complex spectra is studied [1]. It is shown that a departure from the Gaussian,
which

is usually employed in such approach, may be observed even in the shape of
unresolved

spectra due to the large value of the kurtosis coe cient. The use of a Gaussian
shape

may also overestimate the width of the spectra in some cases. Therefore, it is
proposed

to simulate the statistical shape of the transition arrays by the more exible
generalized

Gaussian distribution which introduces an additional parameter - the power of
the argument

in the exponential - that can be constrained by the kurtosis value. The
relevance

of the new statistical line distribution is checked by comparisons with smoothed
spectra

obtained from detailed line-by-line calculations. The departure from the
Gaussian is also

con rmed through the analysis of 2p ! 3d transitions of recent absorption
measurements

[2-4]. A numerical t is proposed for an easy implementation of the new
statistical pro le

in atomic-structure codes.

[1] F. Gilleron, J. C. Pain, J. Bauche and C. Bauche-Arnoult, Phys. Rev. E 77,
026708

(2008)

[2] C. Chenais-Popovics et al., Astrophys. J. Suppl. Ser. 127, 275 (2000).

[3] J. Bruneau et al., Spectral Opacity experiments, (Symposium Science on large
lasers,

Saclay, 1997).

[4] J. E. Bailey et al., J. Quant. Spectrosc. Radiat. Transfer 81, 31 (2003).

CP 189

211

Exact and statistical methods for computing the

distribution of states, levels and E1 lines in atomic

spectra

J.C. Pain and F. Gilleron

Commissariat a l'Energie Atomique,

Centre DAM ^Ile-de-France, Bruy eres-le-Ch^atel, 91297 Arpajon Cedex, France

We propose di erent methods in order to determine the distribution P(M) of
quantum

states M (projection of total angular momentum J) inside a relativistic or
non-relativistic

con guration. This distribution is used to calculate: (i) the distribution of
levels [1] of a

con guration and (ii) the number of electric-dipolar (E1) lines between two con
gurations.

First, an e cient recursive approach is presented for an exact calculation of
P(M) [2].

Second, the statistical approach of Bauche et al. [3] is improved to account for
high-l

spectators (e.g. i1pN) which occur for instance in electron capture into
high-lying Rydberg

states in collisions between multiply charged ions and light target gases [4].
In that case,

P(M) may exhibit a plateau, which can neither be modeled by a Gaussian nor by a

Gram-Charlier expansion series. We show that the Generalized Gaussian, which
exponent

is completely determined by the kurtosis (reduced fourth-order centered moment)
4 of

P(M), is more suited for such cases. We propose an analytical formula for the
evaluation

of the number of E1 lines with a larger range of applicability.

[1] E. U. Condon and G. H. Shortley, The Theory of Atomic Spectra (Cambridge:
Cambridge

University, 1935).

[2] F. Gilleron and J. C. Pain, to be published.

[3] J. Bauche and C. Bauche-Arnoult, J. Phys. B: At. Mol. Phys. 20, 1659 (1987).

[4] P. Hvelplund, H. K. Haugen, H. Knudsen, L. Andersen, H. Damsgaard and F.
Fukusawa,

Phys. Scr. 24, 40 (1981).

CP 190

212

Laser optogalvanic spectroscopy of Lanthanum in

Spectral range of Rhodamine 6G.

Nighat Yasmin, R Islam

Laser Development Division, National Institute of Lasers and Optronics Nilore

Islamabad

Hyper ne structure studies of some of the allowed transitions of La I has been
carried out

by high resolution Doppler limited laser optogalvanic spectroscopy. A narrow
bandwidth

(500 KHz) Autoscan ring dye laser (899-29) pumped by argon ion laser model
Innova

series 200 ( coherent Corp) has been employed to investigate the hyper ne
structure in

the wavelength range 5600-6200 A of Rhodamine 6G in connection with a
commercially

available hollow cathode. Sixteen transitions of La I have been observed
involving twenty

ve levels, twelve with odd and thirteen with even parity. A comparison with the
previous

data available in the literature has also been made.

The recorded spectra were analyzed using Casimir's formula which yields the
expression

for the shift of a hyper ne component from the center of the gravity. Then we
formulate

four simultaneous equations for the four unknown quantities A, B, A0 and B0
according

to the expression. i.e;

12 = AK1K2

2 + 3B

8

[K1(K1+1)K2(K2+1)]

IJ(2I1)(2J1)

+A0K0

1 K0

2

2 + 3B0

8

h

K

0

1

K

0

1+1

K

0

2

K

0

2+1

i

IJ0(2I1)(2J01)

A computer program based on Gauss elimination technique is then employed to
determine

the hyper ne structure constants i.e. A, B, A0 and B0 for lower and upper energy
levels.

The curve obtained through the utilization of these empirically evaluated hyper
ne struc-

ture constants is then matched with the experimental data through another
computer

program for the best- t values.

Here we present the analyzed data of only few transitions. Experimentally
obtained

hyper ne structure constants (in MHz) of these transitions along with the
tranisition

wavelengths are shown below.

Lower level Upper level

A

E(cm1) Con g. Term J A B E (cm1) Con g. Term J A B

5677.707 2668.2 5d2(3F)6s 4F 3/2 -487.3 62.88 20338.3 5d2(3F)6p 4F 3/2 254.8
97.63

5690.6 0.00 5d6s2 2D 3/2 141.2 44.78 17567.49 5d6s(3D)6p 4P 1/2 2892.1 0.00

5699.241 13747.28 3d3 4F 9/2 -63.8 -26.2 31287.646 5d6s(3D)7s 4D 7/2 -565.5 800

5699.348 4121.572 5d2(3F)6s 4F 9/2 489.5 32.18 21662.51 5d2(3F)6p 2G 7/2 283.5
55

5720.009 3494.58 5d2(3F)6s 4F 7/2 461.3 21.6 20972.22 5d2(3F)6p - 5/2 -65,74
37.42

5742.922 7231.36 5d2(3P)6s 4P 1/2 2460.0 0.00 24639.27 5d2(3P)6p 4S 3/2 -197.3
26.0

5744.384 7679.94 5d2(3P)6s 4P 5/2 798.5 826.6 25083.42 5d2(3P)6p 4D 7/2 67.5
820.2

5821.975 9960.96 5d2(1G)6s 2G 7/2 -289.2 72.40 27132.5 5d2(1G)6p 2G 7/2 69.1
42.6

5829.692 7490.46 5d2(3P)6s 4P 3/2 936 37.6 24639.27 5d2(3P)6p 4S 3/2 -221 -140

5845.034 1053.2 5d6s2 2D 5/2 182.1706 54.213 18157.0 5d6s(3D)6p 4P 5/2 651.5 115

CP 191

213

Investigation of the even parity states of group II-B

elements (Zn, Cd and Hg)

Ali Nadeem

Photonics Division, National Institute of Lasers and Optronics (NILOP),
Islamabad,

Pakistan

Systematic studies of the group-IIB (Zn, Cd, Hg) elements have been carried out
to

investigate highly excited even-parity triplet states. The inter-combination
msnp 3P1

levels of these atoms can be populated relatively easily using ultra violet
laser light and

can serve as intermediate levels. The lack of spectroscopic studies on the bound
states

of these atoms is primarily due to the fact that their ionization potentials
lies in the

VUV region. As already said, their resonance transitions lie in the UV region
(Cd,

Zn) and in the VUV region (Hg). Consequently, multi-photon and multi-step
ionization

techniques have not been employed so far to probe the highly excited states of
these atoms.

The experimental set-up comprised of two frequency doubled dye lasers
simultaneously

pumped by a common Q-switched Nd:YAG (532nm; 355nm) laser operating at 10Hz

repetition rate and 7ns pulse duration. To record the spectra, a thermionic
diode ion

detector working in the space charge limited mode was used. The change in the
diode

current due to the photo-ion production was measured as a voltage drop across a
100 kΩ

load resistor.

The new observations for cadmium include the term energies and quantum defects
of 5snd

3D2 (11 < n < 52) and 5sns 3S1 (12 < n < 38) Rydberg series whereas the 5snd 1D2

series have been detected from n = 11 to 26. The appearance of 5snd 1D2 is
because

the Δ S = 0 selection rule is relaxed, then triplet to singlet transitions are
observable.

The ratio of the transition probabilities in cadmium indicates that the 1P1
contribution

to the 3P1 wave function is 0.2%, whereas in zinc it is 0.02% and in mercury it
is 3.2%.

The singlet-triplet mixing determines the intensities of the excited triplet
states. The

relative intensities of the excited states have been described according to
electric dipole

selection rules. The first ionization potential of cadmium has been determined
from

the unperturbed 5snd 3D2 series. From the termination of the Rydberg series we
have

estimated the net electric field present in the interaction region using the
E(V/cm) =

1.23 x 109 n5

m relation. During experiments on zinc the two metastable levels 4s4p 3P0

and 4s4p 3P2 also get populated through collisions. The average thermal energy
of atoms

corresponding to 823K is 572cm−1 which is sufficient to populate these fine
structure

components in zinc. New observations include 4snd 3D2 (14 < n < 55) and 4sns 3S1
(15

< n < 35) Rydberg series excited from the 4s4p 3P1 level. In addition, 4snd 3D3
(13 < n

< 49) and 4snd 3D1 (10 < n < 20) series including few members of the 4sns 3S1
series were

also observed exciting the 4s4p 3P0 and 4s4p 3P2 states, respectively. The wave
function

mixing in zinc is very small therefore no singlet transitions are detected. In
mercury we

have observed the even-parity 6snd 3D2 (25 < n < 52) series and few levels of
the 6sns

3S1 series. Although the wave function mixing of the 1P1 and 3P1 is much higher
than for

Cd and Zn and thus the 6snd 1D2 series should be present with high intensity
compared

to that in zinc and cadmium, these series is completely absent in the spectra of
mercury.

CP 192

214

New levels of Pr I dicsovered via infrared spectral

lines

Z. Uddin1, L. Windholz1, F. Akber2, M. Jahangir2, I. Siddiqu1

1Institute of Experimental Physics, Technical University of Graz, Austria

2Department of Physics, University of Karachi, Pakistan

The Fourier transform (FT) spectrum of Praseodymium [1] shows hundreds of
spectral

lines in the infrared and far infrared region, many of them are unclassi ed. We
have

classi ed lot of them by their hyper ne (hf) structures and level energy di
erences. Still

we found a number of lines, which could not be explained as transitions between
known

levels; this indicated that up to now unknown energy levels of Pr are involved.
Some of

the hyper ne structures in the FT spectrum have a very good signal to noise
ratio, thus

a t of these structure was possible. In this way we found 15 new levels of Pr I.
For one

of them we give the following details:

The line 8954.659 A is a line already classi ed [2] as a transition between the
upper

level 31787 cm1 (J = 5.5, odd parity) and the lower level 20622.7 cm1 (J =
6.5 ,

even parity). However, the hf structure in the FT spectrum does not match with
the hf

structure corresponding to this transition. A t of the hf structure suggested a
transition

4.5 - 4.5 with hyper ne constant A of the lower level close to 810 MHz. With
help of

this value we identi ed the lower level to be 11713 cm1, J = 4,5, even parity.
Adding

the wave number of the line (center of gravity wavelength corrected to 8954.681
A), we

introduced a new upper level 22877 cm1, J = 4.5, odd parity. This new level of
Pr

I explains 10 lines shining up in the FT spectra. Six of them were already known
but

unclassi ed lines, three of them are new lines, one classi cation was wrong (see
table).

From the line 5419.935 A we determined the nal value of the level energy,
22877.524

cm1, assuming that the energy 4432.24 cm1 of the lower level is correct.

Lines classi ed by new level 22877.524 cm1, J = 4.5, A = 932 MHz, odd parity:

Lower level with even parity

Wavelength ( A) J Energy (cm1) A (MHz) Remarks

5419.935 4.5 4432.24 929 unclassi ed line

6035.419 5.5 6313.25 756.3 unclassi ed line

6117.513 3.5 6535.52 979 unclassi ed line

7346.179 5.5 9268.75 976 new line

7714.313 3.5 9918.17 1057 unclassi ed line

8349.517 5.5 10904.07 301 new line

8825.330 4.5 11549.61 1064 unclassi ed line

8954.681 4.5 11713.22 818.5 wrong classi ed line

9471.136 3.5 12321.92 870.5 new line

9671.920 4.5 12519.72 693 unclassi ed line

[1] B. Gamper, Diploma thesis, Graz 2007, unpublished

[2] A. Ginibre-Emery, PhD thesis, Paris 1988

CP 193

215

New lines of atomic niobium in Fourier transform

spectra with enhanced sensitivity

Alev Er1, Ipek K. ¨ Ozt¨urk1, G¨on¨ul Ba¸sar1, Sophie Kr¨oger2, G¨unay Ba¸sar3,

Andrey Jarmola4, Maris Tamanis4, and Ruvin Ferber4

Istanbul University, Faculty of Science, Physics Department, 34134 Vezneciler,
Istanbul,

Turkey

Technische Universit¨at Berlin, Institut fr Optik und Atomare Physik,
Hardenbergstr.36,

10623 Berlin, Germany

Technical University of Istanbul, Faculty of Science and Letters, Physics
Engineering

Department, 34469 Maslak, Istanbul, Turkey

University of Latvia, Faculty of Physics and Mathematics, Laser Centre, 19
Rainis

Blvd., Riga LV-1586, Latvia

This work is a continuation of our hyperfine structure studies of the atomic
niobium. Recently,

the spectrum of Nb from a hollow cathode discharge was recorded in the
wavelength

region from 330 nm to 800 nm with a high-resolution Bruker IFS 125HR Fourier
transform

spectrometer in Riga with resolution of 0.02 cm−1 [1]. To increase the
sensitivity of the

Fourier transform measurements, an interference filter was introduced in the
beampass

to limit the spectral range of the light that came from the hollow cathode
discharge and

entered to the Fourier transform spectrometer. We used different interference
filters in

the range of 410 nm to 670 nm, each with spectral bandwidth of about 10 nm. By
this

method a strong increase of the signal-to-noise ratio has been obtained. Even
lines that

had not been seen at all in the previous measurements by Fourier transform
spectroscopy

(without filter), now become clearly visible. The measured spectra include some
previously

unknown Nb spectral lines not listed in the wavelength tables [2,3] as well as
lines

without classification [2]. The hyperfine structure profiles of the spectral
lines have been

analyzed with a least-squares-fit procedure assuming a Doppler profile.
Experimental hyperfine

structure constants A of atomic niobium were determined. For unclassified lines,

several fits were performed assuming different values of angular momentum J for
the fine

structure levels involved. The J values of the best fit together with the
resulting hyperfine

structure constants A, provide relevant information for the classification of
the transitions.

Riga team acknowledges support from LZP grant No. 04.1308. A.J. is grateful for
support

from ESF grant.

[1.] A. Er eet al., paper in preparation

[2.] C. J. Humphreys and W.F. Meggers, National Bureau of Standards, Vol. 34,
(1945)

[3.] Frederick, M. Phelps III, M.I.T. Wave-Length Table, Volume 2: Wavelength by

element, The MIT Press, Cambridge, Massachusetts, London, England (1991).

CP 194

216

Configuration interaction effects in the fine- and

hyperfine structure of the even configuration system

of tantalum atom

J. Dembczy´nski, M. Elantkowska, J. Ruczkowski

Chair of Quantum Engineering and Metrology, Faculty of Technical Physics, Poznan

University of Technology, Nieszawska 13B, 60-965 Poznan, Poland

E-mail: jerzy.dembczynski@put.poznan.pl

The experimental work of L.Windholz and co-workers, concerning observation of
the tantalum

spectrum, yield many informations about new energy levels and hyperfine
structure

splittings.

We contribute the results of the complex parametric studies of the fine- and
hyperfine

structure of the mentioned element up to second-order of perturbation theory.
The work

has been performed for the systems including 36 even configurations. The values
of

the radial parameters describing the one- and many-body interactions effects on
atomic

structure are given. We predicted values of energy levels and their A- and B-
hyperfine

structure constants, also for experimentally levels not observed up to now.

This work was supported by Polish Ministry of Science and Higher Education under
the

project N519 033 32/4065

CP 195

217

Extended analysis of the even con gurations of Ta II

Ewa Stachowska1, Jerzy Dembczy nski1 and Laurentius Windholz2

1Chair of Quantum Engineering and Metrology, Pozna n University of Technology,

Pozna n, Poland

2Institute of Experimental Physics, Graz University of Technology, Graz, Austria

The structure of Ta II is of particular interest in astrophysical studies,
especially of chem-

ically peculiar stars, such as Lupi.

This work extends the analysis of the complex atomic structure of the tantalum
ion, using

extensive ne and hyper ne structure calculations of the system of the following
25 even

con gurations :

5d4 + 5d3n0g (n0=5-6) + 5d36s + 5d36d + 5d26s2 + 5d26sn0g (n0=5-6) + 5d26sn00d
(n00=6-10)

+ 5d26sn000s (n000=7-10) + 5d25f6p + 5d26p2 + 5d6s2n00d (n00=6-7) + 5d6s6p2 +
5d5f6s6p

+ 5d5f6s7p + 5d6s6d7s.

Previously only low lying levels of the (5d + 6s)4 con guration system up to
40000 cm1

were well known, identi cation supported by their hyper ne structure. Levels of
higher

con gurations, from 70000 cm1 upwards are found, but their identi cation is
still lacking

and further study is needed. Results will be presented at the conference.

This work was partially supported by PUT (project DS 63-029/08).

CP 196

218

Search for new electronic levels in singly ionized

europium Eu II

B. Furmann

Chair of Quantum Engineering and Metrology

Faculty of Technical Physics, Poznan University of Technology

boguslaw.furmann@put.poznan.pl

Experimental search for new electronic levels in rare earths, combined with
determination

of the parameters, which allow a correct classification of those levels, such as
J quantum

number, gJ factor or hyperfine structure constants A and B, has an significant
influence

on both the improvement of precision of the theoretical description of
interactions in

particular atoms (particularly in a semi-empirical method) and some applications
in other

branches of physics, e.g. investigations of abundance of particular atoms or
ions in stellar

atmospheres [1].

In the case of europium ion Eu II the electronic levels system is slightly
different from the

typical pattern of other lanthanides. The known electronic levels of the odd
configurations

4f76s and 4f75d have energies in the range 0-17500 cm−1. Above this value a
large gap

is present and the next levels can be found at the energies above 50000 cm−1. On
the

other side, theoretical predictions [2] yield an energy gap in the system of
electronic levels,

but only covering the range 17500-26000 cm−1; at energy values between 26000
cm−1 and

50000 cm−1 several tens of electronic levels should occur. The tables of
spectral lines of

Eu II [3] contain several tens of unclassified spectral lines.

In the present contribution results of search of new electronic levels, based on
investigations

of the hyperfine structure of unclassified spectral lines with the method of
laser

induced fluorescence in a hollow cathode discharge, are presented. The method of
investigation

has been similar to the one applied earlier for praseodymium ion [4]. On the

basis of the measured hyperfine A constants and determined fluorescence channels
wavelengths,

combined with gJ values presented in [3], it has been possible to assign the
levels

investigated to the theoretically predicted ones, however, their energies have
not been

determined so far. A plan of continuations of the investigations is presented.

The work has been supported by Poznan University of Technology under project No

63-029/2008

References

[1] C. Travaglio, D. Galli, R. Gallino, M. Busso, The Astrophys. Journal 521,
691-702,

(1999)

[2] J. Dembczynski, M. Elantkowska, J. Ruczkowski Private communication

[3] H. N. Russel, W. Albertson, and D. N. Davis, Phys. Rev 60 , 641-656, (1941)

[4] B. Furmann, D. Stefanska, J. Dembczynski, E. Stachowska, Physica Scripta 72,
300-

308, (2005)

CP 197

219

Analysis of the odd configurations of tantalum atom

search for configurations containing f electrons

B. Arcimowicz, J. Dembczy´nski

Chair of Quantum Engineering and Metrology, Faculty of Technical Physics, Poznan

University of Technology, Nieszawska 13B, 60-965 Poznan, Poland

E-mail: bronislaw.arcimowicz@put.poznan.pl

Recently the structure of tantalum atom has been extensively investigated, in
particular

by three groups: from Graz, Hamburg and Pozna´n. So far the energies of more
than 260

electronic levels, belonging to odd configurations of tantalum atom, have been
established

and their hyperfine structures have been determined. Attempts at classification
of those

levels, based on the semi-empirical calculations, have been made. The
wavefunctions

obtained in this procedure have further been used to calculate the A and B
hyperfine

structure constants. However, only for less than twenty lowest-lying levels a
satisfactory

agreement has been obtained. Results of the analysis indicated a strong
configurations interaction.

Semi-empirical calculations performed in the multiconfiguration approximation

5d4n0p + 5d36sn0p + 5d26s2n0p (where n0=6-10) with conservation of the values of
effective

quantum numbers neff have still omitted several levels with energies in the
range 40000-

50000 cm−1. It suggested the existence of other configurations, which positions
were,

however, inconsistent with predictions based on multiconfiguration Hartree-Fock
calculations.

Taking into account 27 or 28 configurations, including additional configurations

of the type 5d36sn00f + 5d26s2n00f + 5d4n00f (where n00=5-7), although it has
improved

the consistency of the fitted parameters gJ and the levels energies with the
respective

experimental values, it nevertheless has not solved some differences. In the
subsequent

stage of calculations an attempt of reduction of the configuration basis to
merely 9 configurations

has been made, but simultaneously some hitherto not considered interactions

in the second order perturbation theory have been included. A better precision
of these

calculations allowed to determine the positions of configurations 5d35f6s and
5d25f6s2.

The lowest-lying level of the former configuration containing the f electron is
the recently

found level of the energy E = 47740.71 cm−1 with the value of hyperfine
structure constant

A=−2500 MHz. For many levels the deciding test of classification have been the

hyperfine structure constants B, which varied strongly, since the values of the
constants

A have been very close to each other. The results obtained are discussed in
detail within

this work

References

[1] N. Jaritz, L. Windholz, U. Zaheer, M. Farooq, B. Arcimowicz, R. Engleman Jr,
J. C.

Pickering, H. J¨ager and G. H. Guth¨ohrlein, Phys. Scr 74, 211-217 (2006)

CP 198

220

Program package for semi-empirical analysis of the

fine- and hyperfine structure of complex atoms

J. Ruczkowski, J. Dembczy´nski, M. Elantkowska

Chair of Quantum Engineering and Metrology, Faculty of Technical Physics, Poznan

University of Technology, Nieszawska 13B, 60-965 Poznan, Poland

E-mail: jerzy.dembczynski@put.poznan.pl

The experimental work combined with semi-empirical calculations is a very
efficient tool

for the investigations of the fine- and hyperfine structure of the complex
atoms.

We present a set of programs for the analysis of the fine- and hyperfine
structure. The

input data for the calculations are : the fine structure energy levels, the gJ
-factors and the

hyperfine structure (hfs) A and B constants of experimentally observed levels.
In order

to avoid mistakes, all input data are set once in the initial input file and are
transferred

between the programs automatically.

The programs are used for the analysis of electron systems containing any number
of

configurations up to four open shells. In the energy matrix generated, all kinds
of electrostatic,

magnetic and correlated electrostatic and magnetic interaction, up to second
order

perturbation theory, were included.

As a result, we obtain predicted energy values for all the levels of the system
considered,

their exact spectroscopic description, eigenvector amplitudes and also gJ
-factors and hfs

A and B constants.

The program package contains supplementary programs useful for clear
presentation of

results of calculations and their analysis.

This work was supported by Polish Ministry of Science and Higher Education under
the

project N519 033 32/4065

CP 199

221

Procedure for precise determination of the hyperfine

structure constants A, B, C and D. Example of

lanthanum atom

M. Elantkowska, J. Ruczkowski, J. Dembczy´nski

Chair of Quantum Engineering and Metrology, Faculty of Technical Physics, Poznan

University of Technology, Nieszawska 13B, 60-965 Poznan, Poland

E-mail: jerzy.dembczynski@put.poznan.pl

High precision measurements of the hyperfine structure (hfs) splittings of
electronic levels,

especially by rf-spectroscopic methods [1, 2, 3] make it possible to study even
fairly complicated

aspects of the interaction between electron shells and the nucleus, which can
result

in determination of the nuclear moments with high accuracy. We report the
parametrization

method of the hyperfine structure which takes into account simultaneously one
and

two-body effects appearing in the second order perturbation theory.

The analysis of the hfs of the even configurations of La atom was performed in
the basis

of 3 configurations taking into account all possibles interactions predicted by
many-body

fine structure theory. In order to include the J-off-diagonal effects in the
hyperfine structure,

direct diagonalization of the matrix containing J-diagonal as well as
J-off-diagonal

elements has to be performed (in the basis of (configuration, vSLJF) states).
Usually,

the repulsion effects of the neighbouring levels with the same quantum number
F are

considered. It requires the precision up to 16 significant digits. The diagonal
part of this

matrix consists of coefficients corresponding to particular components of the
energy of a

hyperfine structure sublevel EF : center of gravity of hfs energy WJ and the
experimental

hfs constants A, B, C and D. These parameters are treated as free in the fitting
procedure

of the experimental and the calculated hfs energies (EF ). The differences
between EF and

EFą1 values are equal to experimentally determined hyperfine structure
intervals. Values

of J-off-diagonal matrix elements are fixed.

As a result, we obtain final values of the hyperfine structure constants, which
can be used

again to determine the radial hfs parameters.

This work was supported by Polish Ministry of Science and Higher Education under
the

project N519 033 32/4065

References

[1] Y. Ting, Phys.Rev. 108, 295, (1957)

[2] W.J. Childs, L.S. Goodman, Phys.Rev. A3, 25, (1971)

[3] W.J. Childs, U. Nielsen, Phys.Rev. A37, 6, (1988)

CP 200

222

Investigations of the Hyperfinestructure of

Praseodymium in the IR-Region with the help of

FTS

Bettina Gamper1 and Laurentius Windholz1

1 Institute of Experimental Physics, Graz University of Technology,

Petersgasse 16, 8010 Graz, Austria

The density of the spectral lines of praseodymium is very high. Therefore there
are a

lot of unknown and not classified lines and levels. One kind of investigation
one can do

is to analyze the fourier-transform-spectra (FTS). That is exactly what we did
in the

IR-region of praseodymium. In this region there are a lot of lines which are not
classified

and therefore not related to a spectral transition between two energetic levels.
If you

look through the FTS you can immmediately see and then also analyze the
characteristic

hyperfinestructure of several transitions.

With the help of FTS we could classify about 200 new spectral lines. That does
not mean

that they are all already related to a spectral transition, some of them are
just marked

as here is a line. The reason why we could not assigne each line to a transition
is that

either the intensity of a line was to weak to see all of their components or
that there was a

blend-situation between severeal ennergetic transitions. One very successful way
to solve

such a problem is to make some investigations via laserinduced
fluorescencespectroscopy.

That would be the next step in our work.

Another thing which we did was that we could correct some energies or
hyperfineconstants

of already known levels or also give a more precise center of gravity of some
lines. As

well we could relate a lot of already classified lines to a spectral transition
between two

previously known energetic levels.

Of course it also was possible to find some new energylevels. That can be done
via fitting

some very intens lines. For example we calculated the following two new levels:

level energy/ cm−1 J value A value/ MHz parity investigated line/ °A

20467.49 2.5 800 o 9293.848

22442.19 7.5 961 o 9319.011

A clear indication that those new energetic levels are correct is that they also
explain

other lines in the spectra.

CP 201

223

Investigation of the hyper¯ne structure of Ta I-lines

P. GÃlowacki1 , L. Windholz2 and J. Dembczyśnski1

1Chair of Quantum Engineering and Metrology, Poznaśn University of Technology

Nieszawska 13B, 60-965 Poznaśn, Poland

2Institute of Experimental Physics, Graz University of Technology Petersgasse
16,

A-8010 Graz, Austria

E-mail: przemyslaw.glowacki@doctorate.put.poznan.pl

Investigations of the hyper¯ne structure in tantalum began in the thirties of
20th century

[1,2]. Numerous research groups all over the world obtained many experimental
results

concerning the tantalum spectrum [3,4,5]. The theoretical group under
supervision of

Prof. Dembczyśnski included all known experimental results in a semi-empirical
analysis

of the electronic structure of tantalum atom. This calculations show that there
are still

plenty of predicted energy levels that require experimental con¯rmation or
discovery.

In our experimental investigations we used a hollow cathode lamp producing free
Ta atoms

by sputtering, which were excited by a tunable dye laser operating with
coumarine 102

(480-510nm). The laser-induced °uorescence was detected. Several spectral lines,
which

appear in a Fourier transform spectra (FTS) and were unclassi¯ed, were excited.
The

energy of some electronic levels and the values of their hyper¯ne constants A
and B were

obtained.

Table I. Ta I lines investigated and classi¯ed by laser excitation.

Excitation

wavelength

Even level Odd level

[ºA, air]

4870.082

4900.354

4909.322¤

4909.395¤

4934.261

4939.771¤

5000.391

5000.981

Energy [cm¡1] J

new 54024.941 3.5

53598.985 3.5

55080.053 4.5

20646.702 3.5

23912.929 4.5

27412.440 1.5

25655.493 2.5

22761.279 3.5

Energy [cm¡1] J

33497.154 4.5

33197.724 3.5

34716.237 5.5

41010.121 2.5

44173.713 4.5

a 47650.666 1.5

45648.307 3.5

42751.800 3.5

¤ - new center of gravity, a - level predicted by calculation from FTS, con¯rmed
by LIF

methods

This work was performed within the project of WTZ PL07/2007.

References

[1] E. McMillan, N.S. Grace, Phys. Rev. 44, 949-950 (1933)

[2] Gisolf and Zeeman, Nature 132, 566 (1933)

[3] G.H. GuthÄohrlein, L. Windholz, Z.Phys D 27, 343-347 (1993)

[4] B.Arcimowicz, A. Huss, S. Roth, N. Jaritz, D. Messnarz, G.H. GuthÄohrlein,
H. JÄager,

L. Windholz, Eur. Phys J. D 13, 187-194 (2001)

[5] N. Jaritz, L. Windholz, U. Zaheer, M. Farooq, B. Arcimowicz, R. Engleman Jr,
J.C.

Pickering, H. JÄager, G.H. GuthÄohrlein, Phys. Scr. 74, 211-217 (2006)

CP 202

224

Perturbed intensity distribution of hyperfine

components of Praseodymium-I lines

I. Siddiqui, B. Gamper, G.H. Guthöhrlein and L. Windholz

Institut für Experimentalphysik, Techn. Univ. Graz, A-8010 Graz, Petersgasse 16,

windholz@tugraz.at

Excitation of Praseodymium-I atoms with wavelength 578.051 nm led to observation
of

laser-induced fluorescence signal at 618.3 nm with anomalous intensity
distribution of the

hyperfine components. The recorded structure appeared to be a convolution of
more than

one structures apparently depicting an excitation and fluorescence blend
situation, which

may be observed when investigating Praseodymium atoms, due to the high level
density.

But the same structure appeared also on all other fluorescence channels, thus we
had to

conclude that more than one transition is always excited, and that either two
lower or two

upper levels form a narrow spaced pair. These levels could disturb each other,
explaining

also the quite unusual intensity distribution of the hyperfeine patterns. The
first part of

the structure showed small components on both sides of the huge diagonal
components,

indicating ΔJ = 0. From the spacing of the components, a transition between
levels

with high angular momentum, 15/2 − 15/2, was suggested, while the strong
decrease of

the intensity of the diagonal components indicated small J-values. A fit of the
structure

with 15/2 − 15/2 gave A-factors which did not coincide with A-factors of already
known

levels, thus we had to conclude that we have excited a transition where lower
and upper

level were up to now unknown. Nevertheless, by an analysis of the wave numbers
of the

observed fluorescence lines we were able to locate the upper level of the
excited transition

at a wave number of 32486.80 cm−1, with J = 15/2 and even parity. Excitation
with

wavelength 618.3 nm confirmed our assumptions concerning energy and J of this
upper

level without doubt; its A-factor was 552.5 MHz. Thus we were able to find also
the wave

numbers of the pair of lower levels excited with 578.051 nm. In further
investigation we

found that another third level is located very close to this pair.

These levels are

15192.090 cm−1, J = 15/2, A = 730 MHz, odd parity

15191.906 cm−1, J = 13/2, A = 730 MHz, odd parity

15191.233 cm−1, J = 13/2, A = 666 MHz, odd parity

During our systematic investigations we found three other new upper levels,
which could

be excited from this level triplet, all showing disturbed intensites of the
hyperfine components.

CP 203

225

Investigation of the hyperfine structure of Pr I lines

in the region 5630 °A to 5830 °A

Shamim Khan, Syed Tanweer Iqbal, Imran Siddiqui and Laurentius Windholz

Institut f¨ur Experimentalphysik, Techn. Univ. Graz, A-8010 Graz, Petersgasse
16,

windholz@tugraz.at

We investigated the hyperfine structures of several spectral lines of
Praseodymium by

using laser excitation in a hollow cathode discharge. Up to now seventeen
unknown energy

levels with odd parity, nine levels with even parity and one ionic odd level
were found.

The region investigated is in between 5630 °A and 5830 °A. The excitation source
is a R-6G

ring-dye laser pumped by a solid state diode-pumped, frequency doubled
Nd:Vanadate

(Nd:YVO4) Verdi V-18 laser system. The dye was pumped at 7.5 W power of pumping

source. We recorded characteristic hyperfine patterns, from which we determined
both

J-values and magnetic dipole interaction constants A of the combining levels.
Using these

constants and excitation and fluorescence wavelengths, we were able to find the
energies

of the new levels. The excitation wavelengths were taken from FT Spectra [1].

Levels confirmed by a second laser excitation are given in the following table.

Excitation Wavelength Signal/Noise in FT Spectra Discovered Odd Levels

°A

J Energy/ cm−1

1 5739.179 6 7.5 25370.613

2 5656.938 7 6.5 26036.412

3 5634.304 22 5.5 26848.512

4 5828.609 4 2.5 28513.813

5 5808.605 17 8.5 28694.509

6 5720.270 4 6.5 30135.271

7 5721.189 4 6.5 30509.771

8 5647.923 2 3.5 30828.498

9 5635.388 3 5.5 31562.583

Discovered Even Levels

°A

J Energy/cm−1

10 5630.85 20 7.5 28474.777

11 5669.693 3 5.5 29363.344

12 5659.606 1 4.5 30485.255

13 5636.680 4 4.5 31962.250

Reference:

1. B.Gamper, Diploma Thesis, Technical University of Graz, 2007 (Unpublished)

CP 204

226

Correction of Pr I energy levels values due to Fourier

transform spectra and laser excitation

G. Krois, G.H. Guthöhrlein and L. Windholz

Institut für Experimentalphysik, Techn. Univ. Graz, A-8010 Graz, Petersgasse 16,

windholz@tugraz.at

The electronic ground state configuration of 59P r141 is [Xe]4f 36s2, with
ground state level

4I9/2. Excitation of one or more electrons of the open f-shell or one of the
s-electrons

forms a huge number of metastable and excited state levels. In our level data
base on Pr

we use in moment approximately 1100 levels of odd and 750 levels of even parity,
but this

list of levels is quite far from being complete.

Due to the high number of levels, the line density is also very high, in average
5 to 10 lines

per Å. In our line list (based on ref.[1]) we have now 20000 spectral lines.
Thus, only with

the help of their hyperfine structure the transitions, explaining the lines, can
be selected.

This classification is supported by a specially developed computer program
(ref.[2]), which

is now extended to show immediately a part of a Fourier transform spectrum (FTS)
[3],

and allows to compare easily calculated hyperfine patterns with structures
appearing in

the FTS (of course for this the hyperfine constants of the combining levels must
be known).

Accurate center of gravity (cog.) wavelengths, obtained fromour calibrated FTS,
allows to

determine more accurate level energies (usually we use for this the vacuum wave
number in

cm−1). Starting from the ground level (which has odd parity), a huge number of
energies

of even upper levels could be corrected. The same is true for upper odd levels,
taking the

lowest even level, 4432.24 cm−1, as basis.

Without accurate level energy and without correct excitation and emission
wavelength

a certain transition can not be identified in the FTS and can not be excited in
laser

spectroscopic studies. This information is given quite often insufficient, as we
have recently

seen for example in ref. [4]. We repeat here the data for one level, published
as new in

[4]: Excitation wavelengths 5885.76; 5829.5; 5800.19; 5707.90 Å, energy 28698.51
cm−1,

odd parity, fluorescence wavelengths 4465.23; 5101.76; 5144.97 Å, A = 767.4(3.3)
MHz.

Identifying with the help of the given A-factor hyperfine structures which may
be decays

of this level, we determined a level energy between 28698.073 cm−1 and 28698.103
cm−1,

depending on the treated line. Moreover, we performed laser excitation with cog.
wavelength

5800.48 Å, and came to 28698.03 cm−1. These different results for the level wave

number show, that the energy differences between the even lower levels are not
completely

correct. Assuming 28698.103 cm−1 as most reliable, we re-calculate the
excitation wavelengths

given in [4] to be 5885.957, 5829.801, 5800.456, 5708.234 Å and the fluorescence

wavelengths to be 4466.053, 5102.419, 5145.418 Å in full agreement with position
and

pattern of lines appearing in the FTS. Taking into account the wavelength
differences up

to 0.5 Å and the high line density, it is nearly impossible to identify the
lines mentioned

in [4]. In general, the energies in [4] are more reliable than the wavelengths,
since the

conversion from vacuum wave number to air wavelength was done quite
insufficient.

[1] A.Ginibre, Thesis, (Paris 1988); [2] L.Windholz, G.Guthöhrlein, Phys. Scr.
T105, 55-

60 (2003); [3] B.Gamper, diploma thesis (T.U. Graz, 2007); [4] B.Furmann,
A.Krzykowski,

D.Stefanska, J.Dembczynski, Phys. Scr. 74, 658 (2006)

CP 205

227

Normal spectral emissivity depending on atomic

composition for two nickel-based and two

ferrous-based alloys at 684.5 nm

C. Cagran1, H. Reschab1, R. Tanzer2, W. Sch¨utzenh¨ofer2, A. Graf2, G.
Pottlacher1

1Institut f¨ur Experimentalphysik, TU Graz, Petersgasse 16, 8010 Graz, Austria

2B¨ohler Edelstahl GmbH & Co KG, Mariazellerstrasse 25, 8605 Kapfenberg, Austria

The Subsecond Thermophysics Workgroup at TUGraz mainly investigates
thermophysical

properties, such as electrical resistivity, specific heat capacity and density
of solid

and liquid metals and alloys as a function of temperature. A fast pulse-heating
system

is used, which also allows the determination of normal spectral emissivity under
pulse

heating conditions. For this purpose, a laser polarimeter, proposed in the
1980s and later

developed by R. M. A. Azzam for the determination of optical constants without
any

moving parts, was adapted for this μs-pulse heating experiment.

The change in polarization of a laser beam reflected off the surface of the
wire-shaped sample

material during a pulse heating experiment enables the measurement of
temperaturedependent

normal spectral emissivity at melting and in the liquid state at the used laser

wavelength. Knowledge of emissivity and its behaviour throughout the liquid
phase can

improve the understanding of interacting effects between light and the molten
alloy. The

industrial cooperation partner B¨ohler Edelstahl GmbH & Co KG is interested in
emissivity

data for numerical simulations of plastic deformation and remelting processes as
well

as for process optimisation.

As observed from numerous experiments with various sample materials the liquid
state

behaviour of normal spectral emissivity at 684.5nm can be classified into three
groups,

namely increasing, decreasing and constant emissivity with increasing
temperature. Based

on this finding, it can be shown that the behaviour of normal spectral
emissivity in

conjunction with the radiometric temperature measurement is needed to achieve
reliable

thermophysical properties of liquid metals.

Within this presentation normal spectral emissivity data at 684.5nm for two
nickel-based

alloys (Nimonic 80A and Inconel 718), as well as the austenitic steel
X2CrNiMo18-14-3

and another ferrous-based alloy at melting and in the liquid state are
presented.

Research supported by B¨ohler Edelstahl GmbH & Co KG and the

Forschungsf¨orderungsgesellschaft

mbH, Sensengasse 1, 1090 Wien, Austria, project 812972.

CP 206

228

Identification of atomic structure in measurement

data, depending on the used set of units

T. H¨upf1, C. Cagran1, G. Pottlacher1, G. Loh¨ofer2

1Institut f¨ur Experimentalphysik, Technische Universit¨at Graz, Austria

2Institut f¨ur Materialphysik im Weltraum, DLR K¨oln, Germany

Hardly any scientific topic can be treated without a closer specification of
quantities. In

natural sciences this is commonly done by choosing an appropriate, standardized
system of

units, generally the SI, or sometimes a ratio of selected quantities. With such
an approach

numerical data are compared to a well-defined unit and reported as a fraction or
multiple

thereof.

The presented work wants to demonstrate how the choice of different units can
lead to a

totally different presentation of results, which might help to reveal yet unseen
coherences.

This idea is reviewed on the example of measurements performed with a fast pulse
heating

method.

Using this pulse heating technique wire shaped samples are resistively volume
heated

as part of a fast capacitor discharge circuit. Time resolved electrical
measurements with

sub-μs resolution include the current through and the voltage drop across the
specimen.

Surface radiance from the samples is detected by pyrometers and the thermal
expansion

of the sample can be monitored by means of a custom-made fast CCD-camera. Based

on these measured quantities, temperature-dependent thermophysical properties
such as

enthalpy, isobaric heat capacity, electrical resistivity and thermal expansion
can be deduced.

During the compilation of specific enthalpy results for numerous pure elements
we observed

an organisation according to the periodic system of the elements. By using molar

instead of specific units the same results become rearranged and show the
established law

of Dulong-Petit.

The project: Electrical Resistivity Measurement of High Temperature Metallic
Melts is

sponsored by the FFG-ASAP programme.

CP 207

229

Electronic Wavefunction Microscopy using

slow-photoelectron Imaging

M. M. Harb[1], A. Ollagnier[1], S. Cohen[2], F. L´epine[1], F. Robicheaux[3], M.

Vrakking[4] and C. Bordas[1]

[1]Universit´e Lyon 1; CNRS; LASIM, UMR 5579, 43 bvd. du 11 novembre 1918,

F-69622 Villeurbanne, France.

[2]Atomic and Molecular Physics Laboratory, Physics Department, University of

Ioannina, 45110 Ioannina, Greece.

[3]Department of Physics, 206 Allison Lab, Auburn University, AL 36849-5311,
USA.

[4]FOM-Institute AMOLF, Kruislaan 407, 1098 SJ Amsterdam, The Netherlands.

Photoelectron imaging spectroscopy has recently emerged as a powerful tool
capable of

providing detailed information on the microscopic properties of matter. In a
standard

velocity map imaging (VMI) experiment eV kinetic energy electrons or ions are
projected

towards a 2D position sensitive detector. Therefore the obtained image
corresponds to the

classical projection of a Newton sphere that, in principle, allows a direct
reconstruction

of the initial 3D velocity distribution of the particles. Improvements on the
standard

VMI set-up, allowing the study of meV electrons, led to the recording of 2D
patterns

which are drastically modified with respect to those obtained with high kinetic
energy

electrons. The most striking effect is the observation of radial signal
modulations due

to quantum interferences [1]. Moreover, ionic core gives rise to a re-scattering
ionization

channel [2]. Simulations based on wavepacket propagation have been performed and

we have shown that when ionization of Hydrogenic atoms occurs via a Stark
resonance

above the saddle point energy, the measured image represents a direct projection
of the

bound component of the electronic wavefunction magnified to macroscopic
dimensions

by a factor 106. Hence it is fully justified to consider the meV-VMI apparatus
as a

photoionization microscope, corresponding to the smallest Youngs slit
experimental setup

ever implemented [3, 4]. For a non-hydrogenic atom, on the other hand, the
presence

of the electronic core leads to mixing of the parabolic electronic states which
modifies the

wavefunction. As a consequence, a smooth evolution of the interferogram patterns
with

energy is expected. Experimental results on Xe and Li will be presented and
discussed.

[1] C. Nicole, H.L. Offerhaus, F. L´epine, C. Bordas, and M. Vrakking, Phys.
Rev. Letters

88 (2002) 133001. [2] C. Nicole, I. Sluimer, F. Rosca-Pruna, M.Warntjes, M.J.J.
Vrakking,

C. Bordas, F. Texier and F. Robicheaux, Phys. Rev. Lett. 85 (2000) 4024. [3] C.
Bordas,

F. L´epine, C. Nicole and M. Vrakking, Phys. Rev. A68 (2003) 012709. [4] F.
L´epine,

S. Zamith, A. de Snaijer,Ch. Bordas and M.J.J. Vrakking, Phys. Rev. Lett. 93
(2004)

233003.

CP 208

230

On a self-sustained oscillating mode for operation of

a glow discharge

E. Dimova, D. Zhechev and V. Ste ekova

Institute of Solid State Physics, Bulgarian Academy of Sciences

72 Tzarigradsko Chaussee Blvd., BG-1784 SOFIA, BULGARIA

e-mail: spectron@issp.bas.bg

Numerous glow discharge (GD) applications are based on its stable mode for
operation.

From another point of view, the gaseous plasma in a GD is known as a typical
nonlin-

ear dynamical "open system" with a large number of degrees of freedom. Within
these

frames a GD modi cation, i.e. hollow cathode discharge (HCD) should possess one
more

additional degree of freedom due to the speci c Penning ionization of sputtered
atoms.

A self-sustained oscillating mode for operation of a hollow cathode discharge
(HCD) is

analyzed based on an equivalent glow discharge RCL scheme. The oscillation takes
place

under i-V operating point of positive di erential resistance and its frequency (
kHz)

depends on the discharge current value. The self-sustained instabilities
correlate with the

plasma space structure in the cathode cavity.

If the value is a small deviation of the continuous discharge current i0 , i.e.
i = i0 + ,

the equation

a ( @ / @t)2 + b ( @ / @t) + d = 0

is found to describe a non damping oscillating function (t) under some
combinations (

a, b, d ) of reasonable data values characterizing glow discharge plasma in
general.

CP 209

231

Atomic beam measurements of the Cs 7d 2D3=2

hyper ne parameters with two-photon uorescence

spectroscopy

A. Kortyna and V. Fiore

Department of Physics, Lafayette College

Easton, PA 18042, U.S.A.

The hyper ne intervals of the 7d 2D3=2 manifold are measured by interrogating an
e usive

beam of atomic cesium with resonant two-photon laser-induced- uorescence
spectroscopy.

This work adapts the laser system previously used to measure hyper ne splittings
in

a vapor cell [1]. Two external-cavity diode lasers drive the two-step excitation
of the

7d 2D3=2 state. One laser is center locked to a 6s 2S1=2(F00) ! 6p 2P3=2(F0)
transition using

magnetic dithering and a servo-feedback circuit. The second laser is scanned
over the

6p 2P3=2(F0) ! 7d 2D3=2(F) transitions.

The scanned laser's frequency scale is calibrated with an electro-optic
modulator. Phase

modulation introduces sidebands to the laser frequency at precise intervals. As
the laser

frequency is scanned across an atomic feature, the sidebands cause the feature
to be

repeated at intervals equal to the modulation frequency, providing calibration
frequency

markers. High accuracy is achieved by directly referencing the modulation
frequency

to the 87Rb 5s 2S1=2(F = 1) $ 5s 2S1=2(F = 2) ground-state hyper ne transition
using

an atomic frequency standard. To enhance resolution, nonlinear tting of Voigt
pro les

is used to locate the centroid of each uorescence peak. The observed linewidths
are

8:2 0:1 MHz, and the hyper ne intervals are determined with overall
uncertainties of

200 kHz. The uncertainty includes contributions from the tting procedure, jitter
in the

frequency scale calibration, and statistical uncertainty.

The hyper ne intervals are used to generate the magnetic dipole coupling
constant A =

7:36 0:03MHz and the electric quadrupole coupling constant, B = 0:1 0:2 MHz.
This

result is the rst time a constraint has been place on the B coupling constant.
The A

coupling constant is in good agreement with a previous measurement [2] but with
an order

of magnitude improvement in resolution. This result does not agree with a
relativistic-

all-order calculation [3], but this disagreement is anticipated because of the
di culty of

modeling electron correlation e ects. Our resolution is su cient to provide a
benchmark

value for testing future improvements in high-precision theory. This work is
generously

supported by Lafayette College and by the U.S. National Science Foundation
through

Grant Numbers PHY-0244684, PHY-0653107, and ECCS-0722610.

References

[1] A. Kortyna, N. A. Masluk, and T. Bragdon, Phys. Rev. A, 74, 022503 (2006).

[2] G. Belin, L. Homgren, and S. Svanberg, Physica Scripta 14, 39 (1976).

[3] M. Auzinsh, K. Bluss, R. Ferber, F. Gahbauer, A. Jarmola, M. S. Safronova,
U. I.

Safronova, and M. Tamanis, Phys. Rev. A 75, 022502 (2007).

CP 210

232

ELECTRON SCATTERING BY CADMIUM

ATOMS

O.B.Shpenik, E.E.Kontros, I.V.Chernyshova

Institute of Electron Physics, National Academy of Sciences of Ukraine

21 Universitetska str., Uzhgorod 88017, Ukraine

E-mail: an@zvl.iep.uzhgorod

We have performed an investigation of elastic and inelastic scattering of
monoenergetic

electrons by cadmium atoms. The specific feature of the experiment is that,
using a

hypocycloidal electron spectrometer, the total electron scattering
cross-section, electron

energy loss spectra as well as constant residual energy spectra (threshold
excitation spectra)

were measured at the same experimental conditions as well as the ionization
crosssection

and excitation function for the lower atomic levels near the threshold.

The experiments were performed using a vapour-filled cell: an electron beam was
formed

by a hypocycloidal electron monochromator [1], passed through the vapour-filled
cell,

then through a hypocycloidal electron analyser and was detected by a deep
Faraday cup.

Inelastically scattered electrons were registered by a separate detector and
measured by

a digital picoamperemeter. Cadmium vapour was supplied to the cell from a
separate

reservoir, its temperature being kept by 20 − 30 0C below the cell temperature.
To

provide spectrometer operation, the axial magnetic field of 150 Oe strength was
used

produced by Helmholtz rings. The detector of positive ions was located directly
in the

cell, performed in a shape of a flat electrode, protected by a metallic grid and
positioned

at a distance of 5 mm from the electron beam.

The threshold excitation spectra of Cd atom, measured at different values of the
residual

electron energy from 0 to 1 eV , have shown a metastable 5 3P− level, then a
resonance

5 1P1− level and the 6 3,1S− level to be the most effectively excited by
electrons.

Taking into account the fact that the hypocycloidal analyzer enables all the
inelastically

scattered electrons to be detected within 0.5−1.5 eV near the level excitation
threshold,

we have measured the excitation functions for the lower 5 3P0,1,2−, 5 1P1−, as
well as

6 3S1− and 6 1S1− levels. The form of the excitation function of the 5 3P0,1,2−
and

5 1P1− levels is very close to the optical excitation functions of (5 1S0 − 5
3P1) and

(5 1S0 − 5 1P1) spectral lines, measured earlier [2].

The work was carried out in part in the framework of the agreement No.
F014/309−2007

of DFFD of the Ministry of Education and Science of Ukraine.

References

[1] N.I.Romanyuk, O.B.Shpenik, I.A.Mandy, F.F.Papp, I.V.Chernyshova, Tech. Phys.

63, 138-147 (1993).

[2] N.M.Erdevdy, O.B.Shpenik, V.S.Vukstich, Opt.Spectr. 97, 559-565 (2004).

CP 211

233

Probing surface vibrations of amorphous solids by helium atom scattering

W. Steurer1, B. Holst1,*, J. R. Manson2, and W. E. Ernst1

1 Institute of Experimental Physics, Graz University of Technology, Austria

2 Department of Physics, Clemson University, South Carolina, USA

contact: wolfram.steurer@tugraz.at

While helium atom scattering has been a well established method for the
investigation of

ordered surface structures, the technique has only recently shown its great
potential for the

non destructive probing of the vibrational state density at amorphous interfaces
[1,2]. No

diffraction can be observed from such interfaces but the energy transfer from
the beam to the

surface and vice versa reveals valuable information about vibrational
frequencies in a way

that is purely surface sensitive with no penetration into the bulk. In the
experiment, a nearly

monochromatic beam of neutral He atoms of about 20 meV kinetic energy impinges
on the

sample surface. Some helium atoms will exchange kinetic energy and momentum with
the

surface via creation or annihilation of surface phonons while others scatter
elastically and do

not change their kinetic energy. Upon arriving at the detector the kinetic
energy of the atoms

is obtained by measuring their time-of-flight. The observed spectrum of energies
is related to

the differential reflection coefficient and, as shown in our recent publication
[1], a surface

phonon spectral density can be obtained. Procedures to determine the vibrational
state density

at an amorphous silica surface and compare it with theoretical models, will be
described in

this contribution.

[1] W. Steurer et al., Phys. Rev. Lett. 99, 035503 (2007).

[2] W. Steurer et a.., Phys. Rev. Lett. 100, 135504 (2008)

* present address: Department of Physics and Technology, University of Bergen,
Norway

CP 212

234

Towards Direct Frequency Comb Spectroscopy using

Quantum Logic

Birgit Brandstatter, Borge Hemmerling, Lukas An der Lan, Piet O. Schmidt

Institut fur Experimentalphysik, Universitat Innsbruck, Technikerstrasse 25,
A-6020

Innsbruck, Austria

A possible change of the ne-structure constant over cosmological time scales
derived from

quasar absorption lines is currently strongly debated. One of the di culties
turns out to

be the lack of precise laboratory data on transition lines of elements with a
complex level

structure such as Ti+ and Fe+ [1].

We challenge this problem by developing a versatile experimental setup in which
spectroscopy

ions are sympathetically cooled by magnesium ions in a linear Paul trap. Using

quantum logic techniques, initial state preparation and state detection of the
spectroscopy

ion can be very e cient. Owing to the complex level structure of these
spectroscopy ions,

repumping from unwanted states is required. We plan to implement this by
applying an

appropriately tailored optical frequency comb.

We will present the latest status of our experimental setup and simulation
results on the

expected uorescence signal from a Ca+ test candidate. We furthermore present
schemes

based on quantum logic techniques to interrogate single ions in order to further
improve

the accuracy of the spectroscopic data.

[1] J. C. Berengut, V. A. Dzuba, V. V. Flambaum, M. V. Marchenko and J. K. Webb,

arXiv:physics/0408017 (2006)

CP 213

235

Towards Cryogenic Surface Ion Traps

Michael Niedermayr1, Muir Kumph1, Piet Schmidt1, Rainer Blatt1;2

1Institut für Experimentalphysik, Universität Innsbruck, Technikerstrasse 25,
6020

Innsbruck, Austria

2Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der

Wissenschaften, Otto- Hittmair-Platz 1, 6020 Innsbruck

One promising approach for scalable quantum information processing (QIP)
architectures

is based on miniaturized surface ion traps [1]. These traps with dimensions in
the

sub-100 m range can be fabricated by photolithography techniques [2]. Generally,
experimental

results indicate that the heating rate of the ions increases with decreasing
trap

dimensions. The mechanism of this heating is not yet fully understood. However,
the

heating rate can be reduced by several orders of magnitude when the trap
electrodes are

cooled from room temperature to 4K [3, 4]. Within a new experiment which is
presently

set up we intend to investigate surface traps at low temperatures in a cryogenic
system.

These traps will be applied for quantum simulations, for fundamental
investigations of

large-scale entanglement and for precision measurements enhanced by quantum
metrology

techniques employing entangled particles.

[1]D. Kielpinski et al., Nature 417, 709 (2002)

[2]J. Chiaverini et al., Quantum Inf. Comput. 5, 419 (2005)

[3]J. Labaziewicz et al., Phys. Rev. Lett. 100, 013001 (2008)

[4]L. Deslauriers et al., Phys. Rev. Lett. 97, 103007 (2006)

CP 214

236

CROSS SECTIONS FOR ELASTIC ELECTRON

COLLISIONS WITH SMALL ALCOHOLS

I. Iga?, I. P. Sanches?, R. T. Sugoharay , M. G. P. Homem? and M. T. Lee?

Departamento de Qu mica, UFSCar, 13565-905 S~ao Carlos, SP, Brazil

yDepartamento de F sica, UFSCar, 13565-905 S~ao Carlos, SP, Brazil

E-mail: diig@ufscar.br

Recently, there is a clear interest on studies of electron scattering by
molecules due to their

key role to physical and chemical transformations in elds of diverse nature,
such as indus-

trial plasmas, radiation damage in biomaterials, etc. Despite these facts, for
most targets

of interest, cross sections values are often not easily available. For instance,
electron colli-

sions cross sections with oxygen containing-organic molecules are very scarce.
Therefore,

in this contribution we will present electron scattering cross sections for
methanol and

ethanol.

Concerning these simple alcohols, their discovery in interstellar space and in
the atmo-

spheres of planets in the solar system has motivated recent studies of electron
interaction

with such species. Also the amount of ethanol vapors in our atmosphere is
certainly ex-

pected to increase in the near future since it is a renewable energy source that
is being

increasingly used as an important bio-fuel to replace at least partially the
usages of fossil

fuels. Nevertheless, information available on the interaction of intermediate
energy elec-

trons and alcohols is still quite limited and mainly directed to the ionization
processes

[1].

In this work we have carried out studies of elastic scattering of electrons in
the inter-

mediate energy range, from ionization threshold to 1 keV. In our experiments
[2], an

electron beam interacts with a gaseous beam formed by alcohol vapors and the
intensities

of elastically scattered electrons are measured as a function of scattering
angle in the (6

- 130 ) angular range. The relative ow technique [3] is used to convert the
experimental

electron intensities to absolute di erential cross sections. Results of measured
cross sec-

tions and their comparison with the calculated data using the independent atom
model

at the static-exchange-polarization level of approximation will be presented
during the

Conference.

We acknowledge support by the Brazilian agencies: CNPq and FAPESP.

References

[1] R. Rejoub, C. D. Morton, B. G. Lindsay, and R. F. Stebbings, J. Chem. Phys.
118,

1756-1760 (2003) 38 3477 (2005) and references therein..

[2] I. Iga, I. P. Sanches, E. de Almeida, R. T. Sugohara, L. Rosani, and M. T.
Lee, J.

Electron Spectr. Relat. Phenom 155 7 (2007).

[3] S. K. Srivastava, A. Chutjian, and S. Trajmar, J. Chem. Phys. 63 2659
(1975).

CP 215

237

Contents

Evening Lecture

EL 1 R.F. Curl jr. (Nobel Price in chemistry 1996)

A brief History of Elemental Carbon

Plenary Lectures

PL 1 S. Haroche

Non-demolition photon counting and field quantum state reconstruction in a
cavity: a new way to look

at light

PL 2 M. Quack

Theory and Spectroscopy of Parity Violation in Chiral Molecules

PL 3 J. Kluge

Precision Experiments with Heavy Ions

PL 4 J. Schmiedmayer

Atom Chips: Integrated circuits for matter waves

PL 5 F. Riehle

Optical Atomic clocks at the Frontiers of metrology

PL 6 A.Weis, P. Moroshkin, V. Lebedev, A. Hofer

Alkali Atoms, Dimers, Exciplexes and Clusters in 4He Crystals

PL 7 M. Scully

Generation of short wavelength radiation via Coherent hyper Raman Superradiance

PL 8 G.M. Tino

Cold Atom Interferometry for Gravitational Experiments

PL 9 Ch. Blondel

Photodetachment microscopy in a magnetic field

PL 10 P. Corkum

Laser induced-Tunneling, Electron Diffraction and Molecular Orbital Imaging

PL 11 A. Scrinzi

Few-electron dynamics in the interaction with strong fields

Invited Progress Reports

PR 1 R. Wester

Molecular Reaction Dynamics at Low Energies

PR 2 C. Champenois, G. Hagel, M. Houssin, C. Zumsteg, F. Vedel, M. Knoop

1, 2, 3 Photons for Trapped Ion Spectroscopy

PR 3 M. Richter, A.A. Sorokin

Non-linear Photoionization in the Soft X-ray Regime

PR 4 U. Becker

Multi-photon ionization and excitation oft the rare gases by Free Electron Laser
radiation

PR 5 F. Lang, K. Winkler, C. Strauss, R. Grimm, J. Hecker-Denschlag

Ultracold deeply-bound Rb2 molecules

PR 6 P. Barker

Manipulating cold molecular gases with intense optical fields

238

PR 7 J.R. Crespo Lopez-Urrutia, S. W. Epp, and J. Ullrich

Resonant laser spectroscopy in the soft x-ray region

PR 8 V.L. Sukhorukov

Resonances in Rare Gas Atoms: Many-Electron Theory and Experiment

PR 9 R. Kienberger

Attosecond spectroscopy in atoms and solids

PR 10 J. Mauritsson

Above, Around, and Below Threshold Ionization using Attosecond Pulses

Contributed Papers

CP 1 F. Ferlaino, S. Knoop, M. Mark, M. Berninger, H. Schöbel, H.C. Nägerl, R.
Grimm

Few-body physics with ultracold Cs atoms and molecules

CP 2 L. Pruvost, H. Jelassi, B. Viaris de Lesegno

Weakly bound molecules: Analysis by the Lu-Fano method coupled to the
LeRoy-Bernstein model.

CP 3 M. Aymar, J. Deiglmayr, O. Dulieu

Calculations of static polarizabilities of alkali dimers and alkali hydrides.
Prospects for alignment of

ultracold molecules

CP 4 L. van Buuren, C. Sommer, M. Motsch, M. Schenk, W.H. Pinkse, G. Rempe

Electrostatically extracted cold molecules from a cryogenic buffer gas

CP 5 H.-D. Kronfeldt, H. Schmidt, B. Sumpf, M. Maiwald, G. Erbert, G. Tränkle

In-situ non-invasive quality control of packaged meat using a micro-system
external cavity diode

laser at 671 nm for Raman spectroscopy

CP 6 D. Pinegar, C. Diehl, R. van Dyck, K. Blaum

3H/3He mass ratio experiment MPIK/UW-PTMS in the context of ν-mass measurements

CP 7 S. Nic Chormaic , D. Gleeson, V. Minogin

Optical microtraps for cold atoms based on near-field diffraction

CP 8 Th. Becker, Th. Germann, P. Thoumany, G. Stania, L. Urbonas, T. Hänsch

Optical Spectroscopy of Rubidium Rydberg Atoms with a 297nm Frequency Doubled
Dye Laser

CP 9 K. V. Rodriguez, V. Y. Gonzalez, L. U. Ancarani, D. M. Mtinik, G. Gasaneo

Helium 1,3S excited states obtained with an angular correlated configuration
interaction method

CP 10 G. Gaigalas, E. Gaidamauskas, Z. Rudzikas

Atomic structure calculations of Cm+4 and Am+3 ions

CP 11 G. Gaigalas, E. Gaidamauskas, J. Bieron, S. Frizsche, P. Jönsson

MCHF calculations of the electric dipole moment of radium induced by the nuclear
Schiff moment

CP 12 Sølve Selstø, J. Bengtsson, E. Lindroth

On the solution of the time dependent Dirac equation for hydrogen-like system

CP 13 M. Safronova, R. Pal, D. Jiang, U. Safronova

Calculation of parity-nonconserving amplitude in Ra+

CP 14 M. Safronova, M.G. Kozlov, W.R. Johnson

Development of the CI + all-order method for atomic calculations

CP 15 K. V. Rodriguez, V. Y. Gonzalez, L. U. Ancarani, D. M. Mtinik, G. Gasaneo

Ground state wavefunctions for two-electron systems with finite nuclear mass

CP 16 O.Y. Khetselius

Laser separation and detecting the isotopes and nuclear reaction products and
relativistic calculating

the hyperfine structure parameters in the heavy-elements

CP 17 A.V. Glushkov, O.Y.Khetselius, A.A. Svinarenko

QED approach to the photon-plasmon transitions and diagnostics of the space
plasma turbulence

239

CP 18 A.V. Glushkov

QED theory of laser-atom and laser-nucleus interaction

CP 19 Kh.Yu. Rakhimov

Quantum dynamics of planar hydrogen atom in a billiard with moving boundaries

CP 20 V.L. Sukhorukov, B.M. Lagutin, I.D. Petrov, A. Ehresmann, L. Werner, s.
Klumpp, K.H. Schartner,

H. Schmoranzer

Interchannel interaction in orientation and alignment of Kr 4p4mp states in the
excitation region of

3d9np resonances

CP 21 O. Rancova, P. Bogdanovich, R. Karpuskiene

Application of new quasirelativistic approach for treatment of oxygen-like Iron
and Nickel

CP 22 Y.S. Kozhedub, D.A. Glazov, I.I. Tupitsyn, V.M. Shabaev, G. Plunien

Relativistic recoil and higher-order electron correlation corrections to the
transition energies in Li-like

ions

CP 23 R. Jursenas

Coupled tensorial forms of atomic two particle operator

CP 24 V.K. Gudym, E.V. Andreeva

The binominal potential of electron-proton interaction alternative to the
Coulomb law

CP 25 J. Bengtsson, E. Lindroth, S. Selstø

The dynamics of meta-stable states described with a complex scaled Hamiltonian

CP 26 L.U. Ancarani, G. Gasaneo

A simple parameter-free wavefunction for the ground state of three-body systems

CP 27 L.U. Ancarani, G. Gasaneo, F.D. Colavecchia, C. Dal Capello

(e, 3e) and (γ, 2e) processes on helium: interplay of initial and final states

CP 28 M.A. Bolorizadeh, R. Fathi, E. Gahnbari-Adivi, F. Shojaei

A three body approach to calculate the differential cross sections for the
excitation of H and He atoms

by proton impact

CP 29 F. Umarov, A. Dzhurakhalov

The peculiarities of elastic and inelastic engery losses at low-energy
ion-surface interactions

CP 30 R. Lomsadze, M. Gochitashvili, B. Lomsadze, N. Tsiskarishvili, D.
Kuparashvili

Study of Mechanism in Alkali Metal Ion Inert Gas Atom Interaction

CP 31 I.I. Shafranyosh, R.O. Fedorko, V.I. Marushka, T.A. Snegurskaya, V.V.
Perehanets, V.V. Stetsovych

Studies of superelastic electron scattering by the metastable Thallium atoms

CP 32 O.B. Shpenik, A.N. Zavilopulo

Ionization and Dissociative Ionization of Adenine Molecules by Electron Impact
near Threshold

CP 33 L. E. Machado, I. Iga, L. M. Brescansin, M.-T. Lee

Absorption effects in intermediate-energy electron scattering by
difluoroethylene

CP 34 S. Houamer, Y. Popov, C. Champion, C. Dal Capello

Charge transfer in collision of protons with water molecule and atomic helium at
high energy

CP 35 S.Y.Kurskov, A.S. Kashuba

Ar(3p5 4p) states excitation in low-energy Ar-Ar collisions

CP 36 S. Gedeon, V. Lazur

Low-energy electron scattering from calcium

CP 37 J.Loreau, M. Desouter-Lecomte, F. Rosmej, N. Vaeck

Ab inition calculation of H + He+ electron transfer cross sections

CP 38 G. Purohit, U. Hitawala, K.K. Sud

TDCS for inner-shell (e, 2e) processes on alkali and alkali earth atoms Na, K,
Be, Mg and Ca

CP 39 P. Syty

The relativistic J-matrix method in scattering of electrons from model
potentials and small atoms

CP 40 V.S. Melezhik, P. Saeidian, P. Schmelcher

Multichannel atomic scattering and confinement-induced resonances in waveguides

240

CP 41 E. Ovcharenko, A. Gomonai, Yu. Hutych

Excitation of forbidden 4d95s2 2D5/2 - 4d105s 2P3/2 transition in In2+ ion at
electron-In+ ion collisions

CP 42 A.O. Lindahl, P. Andersson, C. Diehl, O. Forstner, K. Wendt, D.J. Pegg, D.
Harnstorp

The electron affinity of Tungsten

CP 43 M. Czarnota, D. Banás M. Berset, D. Chmielewska, J-Cl. Dousse, J.
Hoszowaska, Y-P Maillard,

O. Mauron, M. Pajek, M. Polasik, P.A. Raboud, J. Rzadkiewicz, K. Stabkowska, Z.
Sujkowski

High resolution measurements of molybdenum L-shell satellites and
hypersatellites excited by oxygen

and neon ions

CP 44 L. Bandurina, V. Gedeon

Electron-impact scattering on boron

CP 45 E. Baszanowska, R. Drozdowski, P.Kaminski, G. von Oppen

Observation of He-He collisions using the anticrossing method

CP 46 V. A. Kartoshkin, S.P. Dmitriev, N.A. Dovator

Spin-exchange cross sections at the interaction between ground state rubidium
and metastable helium

atoms

CP 47 V. A. Kartoshkin

Spin exchange and redistribution of the spin-polarization at the interaction
between ground state

alkali atoms and nitrogen atoms in gas discharge

CP 48 L. Klosowski, M Piwinski, D. Dziczek, K. Pleskacz, S. Chwirot

Large angle e-He scattering - coincidence experiment with magnetic angle changer

CP 49 M.T. Bouazza, C. Benseddik, M. Bouledroua

Diffusion coefficient and viriel coefficient of Krypton Atoms in a Argon Gas at
Low and Moderate

Temperature

CP 50 M.T. Bouazza, M. Bouledroua

A theoretical report on ultracold collisions of two monatomic Cesium

CP 51 V.M.Entin, I.I.Beterov, I.I. Ryabtsev, D.B. Tretyakov

Tomography of laser cooled atoms in MOT using Rydberg state excitation

CP 52 M. Mestre, F. Diry, B. Viaris de Lesegno, L. Pruvost

Spatial light modulators for cold atom manipulation

CP 53 O. Gorceix, Q. Beaufils, R. Chicireanu, T. Zanon, A. Crubellier, B.
Laburthe-Tolra, E. Maréchal,

L. Vernac, J-C. Keller

All-optical Bose-Einstein condensation of Chromium atoms and rf spectroscopy of
cold Cr2 molecules

CP 54 M. Seliger, U. Hohenester, G. Pfanner

Entangled photons from excitonic decay in artificial atoms

CP 55 J. Grond, U. Hohenester, J. Schmiedmayer

Optimizing number sqeezing when splitting a mesoscopic condensate

CP 56 I.E. Mazets, T. Schumm, J. Schmiedmayr

Breakdown of integrability in a quasi-one-dimensional ultracold bosonic gas

CP 57 J-F. Clément, J-P. Brantut, M. Robert de St. Vincent, G. Varoquaux, R.A.
Nyman, A. Aspect,

T. Bourdel, P. Bouyer

Light-shift tomography in an optical-dipole trap

CP 58 H. Knöckel, S. Liu, I. Sherstov, C. Lisdat, E. Tiemann

Matter wave interferometry with K2 molecules

CP 59 E. Maréchal, B. Laburthe-Tolra, L.Vernac, J.-C. Keller, O. Gorceix

A magnetic lens for cold atoms tuned by a rf field

CP 60 T. Pfau, Th. Lahaye, J. Metz, B. Fröhlich, T. Koch, A. Greismaier

Stability and d -wave collapse of a dipolar BEC

CP 61 K. Chebakov, N. Kolachevsky, A. Akimov, I. Tolstikhina, P. Rodionov, S.
Kanorsky, V. Sorokin

Blue cooling transitions of thulium atom

241

CP 62 J.Sczepkowski, R. Abdoul, R. Gartman, W. Gawlik , M. Witkowski, J.
Zachorowski, M. Zawada

Free-fall expansion of finite-temperature Bose-Einstein condensed gas in the non
Thomas-Fermi

regime

CP 63 N. Kolachevsky, E. Tereschenko, M. Egorov, A. Sokolov, A. Akimov, V.
Sorokin

Resonance Interaction between Cold Rb Atoms and a Frequency Comb

CP 64 M. Witkowski, R. Gartman, W. Gawlik, J. Szczepkowski, M. Zawada

Optical tailoring of spatial distribution of the BEC and non-degenerate cold
atoms. Non-periodic

optical lattice

CP 65 F. Tantussi, N. Porfido, F. Prescimone, V. Mangasuli, M. Allegrini, E.
Arimondo, F. Fuso

Laser techniques for atom-scale technologies

CP 66 F. Fuso, M. Bassu, F. Tantussi, L.Strambini, G. Barillaro, M. Allegrini

Emission from Silicon/Gold nanoparticle systems

CP 67 I.Ulfat, J. Adell, J. Sadowski, L. Ilver, J. Kanski

As3d Core Level Phooemission Studies of (GaMn)As annealed under As capping

CP 68 N. Alinejad, M. Jahangir, F. Izadi

Pulsed laser Deposition Simulation for Graphite Target using Mont-Carlo Method

CP 69 C. Diehl, D. Pinegar, R. S. Van Dyck Jr, K. Blaum

Precision Measurement of the 3He-3H mass ratio with the MPIK/UW-PTMS

CP 70 A. Alonso-Medina, C.Colón, C. Herrán-Martínez

Measured of different atomic parameters of some elements (Ca, Sn, Pb) in a
plasma generated by

Laser-Induced Breakdown Spectroscopy (LIBS)

CP 71 T. Carette, C. Drag, C. Blondel, C. Delsart, C. Froese Fischer, M.
Godefroid, O. Scharf

Isotope shift in the electron affinity of sulfur

CP 72 A.K. Kazansky, N.M. Kabachnik

Theoretical study of attosecond chronoscopy of strong-field atomic
photoionization

CP 73 A.V. Glushkov, O.Y.Khetselius, A.V. Loboda

Generation of ultra-short X-ray pulses in cluster system during ionization by
femto-second optical

pulse

CP 74 J. Alnis, A. Matveev, T. W. Hänsch, C. Parthey, N. Kolachevsky

Long-term stability of high-finesse Fabry-Perot resonators made from
Ultra-Low-Expansion glass

CP 75 H.-D. Kronfeldt, H. Schmidt

Application of Surface-Enhanced-Raman-Scattering (SERS) for In-Situ Detection of
PAHs in

Sea-Water

CP 76 S. Qamar Hussain, M. Saleem, A. Baig

Laser Based Isotopic Separation of Atoms

CP 77 D. Gleeson, V. Minogin, S. Nic Chormaic

Atomic fluorescence coupled into a thin optical fibre

CP 78 D.U. Matrasulov, T.A. Ruzmetov, D.M. Otajanov, P.K. Khabibullaev, A.A.
Saidov, F.C. Khanna

Nonlinear dynamics of atoms in a cavity

CP 79 G.G. Grigoryan, Y. Pashayan-Leroy, C. Leroy, S. Guèrin

Storage of optical pulses in solids despite fast relaxation

CP 80 M. Motsch, M. Zeppenfeld, G. Rempe, W. Pinkse

Purcell-enhanced Rayleigh scattering into a Fabry-Perot cavity

CP 81 M. Agre

Cicular and elliptical dichroism effects in two-photon disintegration of atoms
and molecules

CP 82 I. L. Glukhov, V. D. Ovsiannikov

Thermal ionization of alkali Rydberg atoms

CP 83 V.D.Ovsyannikov, E. Yu.Ilinova

Hyperpolarizabilities of multiplet Rydberg states in alkali and alkaline-earth
atoms

CP 84 N. N. Bezuglov,, K. Miculis, A. Ekers, J. Denskat, C. Giese, T. Amthor, M.
Weidemueller

Penning ionization of cold Rb Rydberg atoms due to long-range dipole-dipole
interaction

242

CP 85 I.I.Beterov, I.I. Ryabtsev, D.B. Tretyakov, N.N Bezuglov, A. Ekers, V.M.
Entin

Ionization of alkali-metal Rydberg atoms by blackbody radiation

CP 86 B. T. Torosov, N.V. Vitanov

Level-crossing transition between mixed states

CP 87 S.Werbowy, J. Kwela

M1-E2 interference in the Zeeman spectra of Bi I

CP 88 E. Efremova, G. Anisimova, R. Semenov, G. Tsygankova

Numerical investigation of Ne I for 2p55g configuration and Ar I for 3p55g
configuration Zeeman

structure

CP 89 A. Papoyan, G. Hakhumyan, A. Atvars, M. Auzinsh, D. Sarkisyan

Method for quantitative study of atomic transitionsin magnetic field based on
vapor nanocell with

L = λ

CP 90 D. Glazov, A. Volotka, V. Shabaev, I. Tupitsyn, G. Plunien

g factor of boronlike ions

CP 91 V. Chernushkin, V. Ovsiannikov

Magnetoelectric Jones spectroscopy of Li and Na atoms

CP 92 A. Kamenski, V. Ovsiannikov

Radiative transition probabilities from D Stark states in orthohelium

CP 93 M. Ryabinina, L. Melnikov

Light-induced quasi-static polarization in hydrogen-like atom under the action
of strong

electromagnetic laser field

CP 94 G.Skolnik, N. Vujicic, T. Ban, S. Vdovic, G. Pichler

Doppler-free spectroscopy of rubidium atoms placed in a magnetic field

CP 95 M. Pawlak, M. Bylicki

Electric field influence on the hydrogen atom embedded in a plasma

CP 96 B. Schnizer, Th. Heubrandtner, E. Rössl, M. Musso

Dynamic and geometric phases in the Stark Zeeman effect of the hyperfines
structure of one-electron

atoms

CP 97 A. Costescu, C. Stoica, S. Spanulescu

New analytical relativistic formulae for the total photoeffect cross section for
the K-shell electrons

CP 98 N.L. Manakov, S.I. Marmo, S.Sviridov

Two-photon above-threshold ionization by a VUV-light

CP 99 N.L. Manakov, S.I. Marmo, S.Sviridov

Above-threshold polarizability of alkali-metal and noble gas atoms

CP 100 V. Richardson, J. Dardis, P. Hayden, P. Hough, E.T. Kennedy, J.T.
Costello, S. Dsterer, W. Li,

A. Azima, H. Redlin, J. Feldhaus, D. Cubaynes, D. Glijer, M. Meyer

Ionisation in Intense Superposed XUV + NIR Laser Fields

CP 101 V.L.Sukhorukov, I.D. Petrov, H. Hotop

Photoionization of excited rare gas atoms Rg(mp5(m+1)p J=0-3) in the
autoionization region

CP 102 S.Y. Yousif Al-Mulla

Spin dependent exchange scattering from ferromagnetic materials

CP 103 K. Alioua , M. Bouledroua, A. Allouche, and M. Aubert-Frécon

Far-wing collisionnal broadening of the Na(3s-3p) line by helium

CP 104 S. Chelli, M. Bouledroua

Excited and ground potassium monatoms perturbed by helium

CP 105 L. Reggami, M. Bouledroua

Pressure broadening of calcium resonance line perturbed by helium

CP 106 E. Saks, I. Sydoryk, N. N. Bezuglov, I. I. Beterov, K. Miculis, A. Ekers

Broadening and intensity redistribution in the atomic hyperfine excitation
spectra due to optical

pumping in the weak excitation limit

243

CP 107 B. Mahrov, C. Andreeva, N. Bezuglov, K. Miculis, E. Saks, M. Bruvelis, A.
Ekers

Reconsideration of spectral line profiles affected by transit time broadening

CP 108 G. Auböck, J. Nagl, C. Callegari, W.E. Ernst

Alkali doped Helium Droplets in a Magnetic Field

CP 109 J. Nagl, G. Auböck, A.W. Hauser, O. Allard, C. Callegari, W.E. Ernst

Quartet alkali trimers on He nanodroplets: Laser spectroscoy and ab initio
calculations

CP 110 R. Hefferlin

Group Dynamics of 2-Atom Even-Electron Molecules and Ions

CP 111 A. Dantan, P. Herskind, J. Marler, M. Albert, M.B. Langkilde-Lauesen, M.
Drewsen

11:30 Cavity-QED with ion Coulomb crystals

CP 112 U. Hohenester, A. Eiguren, S. Scheel, E.A. Hinds

11:45 Spin flip lifetimes in superconducting atom chips

CP 113 A. Cerè, V. Parigi, M. Abad, F. Wolfgramm, A. Predojevic, M. Mitchell

12:00 Interaction-Free Measurement of the Degree of Polarization of an Atomic
Ensemble

CP 114 J. Koperski, M. Krosnicki, M. Strojecki

12:15 Entangled atom-pairs from dissociated dimers: an experimental test of Bell
inequality for atoms

CP 115 G. Casa, A. Castrillo, G. Galzerano, R. Wehr, A. Merlone, D. Di Serafino,
P. Laporta, L.Gianfrani

11:00 Primary gas thermometry by means of near-infrared laser absorption
spectroscopy and determination

of the Boltzmann constant

CP 116 V. Batteiger, M. Herrmann, S. Knünz, A. Ozawa, A. Vernaleken, G.
Saathoff, M. Semczuk, F. Zhu,

H. Schuessler, Th. Hänsch, T. Udem

11:15 Towards precision spectroscopy in the XUV

CP 117 P.F. Staanum, K. Hojbjerre, R. Wester, M. Drewsen

11:30 Probing isotope effects in chemical reactions using single ions

CP 118 N.A. Matveeva, A.V. Taichenachev, A.M. Tumaikin, V.I. Yudin

11:45 Laser cooling of unbound atoms in nondissipative optical lattice

CP 119 R. Lammegger, E. Breschi, G. Kazakov, G. Mileti, B. Matisov, L. Windholz

11:30 Investigations on the lin||lin CPT and its application in quantum sensors

CP 120 J. Klein, F. Beil, T. Halfmann

11:45 Optically Driven Atomic Coherences: from the gas phase to the solid state

CP 121 F. A. Hashmi, M. A. Bouchene

12:00 Slowing light and coherent control of susceptibility in a duplicated
two-level system

CP 122 T. Pfau, R. Heidemann, U. Raitzsch, V. Bendkowsky, B. Butscher, R. Löw

12:15 Rydberg excitation of a Bose-Einstein Condensate

CP 123 S. Kreim, K. Blaum, H. Kracke, A. Mooser, W. Quint, C. Rodegheri, S.
Ulmer, J. Walz

11:30 Progress towards a high-precision measurement of the g-factor of a single,
isolated (anti)proton in a

double Penning trap

CP 124 R. E. Zillich, M. Leino, A. Viel

11:15 Helium-4 Clusters Doped with Excited Rubidium Atoms

CP 125 M. Koch, J. Lanzersdorfer, G. Auböck, J. Nagl, C. Callegari, and W. E.
Ernst

11:30 Progress in optically-detected spin-resonance on helium droplets

CP 126 I.I. Ryabtsev, D.B. Tretyakov, I.I. Beterov, V.M.Entin

11:45 Effect of finite detection efficiency on the observation of the
dipole-dipole interaction of a few

Rydberg atoms

CP 127 A.V. Glushkov, O.Yu. Khetselius, S.V. Malinovskaya, Yu. V. Dubrovskaya

Energy approach to discharge of metastable nuclei during negative muon capture

CP 128 A.V. Glushkov

Resonance phenomena in heavy ions collisions and structurization of positron
spectrum

CP 129 O.Y. Khehtselius

Dynamics of the resonant levels for atomic and nuclear ensembles in a laser
pulse: optical bi-stability

effect and nuclear quantum optics

244

CP 130 A.V. Glushkov, O.Y.Khetselius, E.P. Gurnitskaya, Yu. V. Dubrovskaya, D.E.
Sukharev

Spectroscopy of the hadronic atoms and superheavy ions: Spectra, energy shifts
and widths, hyperfine

structure

CP 131 K. Katsonis, Ch. Berenguer, R. Srivastava, L. Sharma, R. Clark, M.
Cornille, A.D. Stauffer

Ar I transition probabilities and excitation cross sections involving the 4s
metastable levels and the

4/5p configurations

CP 132 G. Malcheva, K. Blageov, R. Mayo, M. Ortiz, J. Ruiz, L. Engström, H.
Lundberg, S.Svanberg,

H. Nilsson, P. Quinet, E. Biémont

Radiative data in the Zr I spectrum

CP 133 G.P. Gupta

Engergy levels, oscillator strengths and lifetimes in C1 IV

CP 134 G.P. Gupta

Large scale CIV 3 calculations of fine-structure energy levels and lifetimes in
Al-like copper

CP 135 C. Colon, A. Alonso-Medina, A. Zanon, J. Albeniz

Levels energies, oscillator strengths, and lifetimes for transition in Pb III

CP 136 E. Träbert

Hyperfine interaction induced decays in highly charged ions

CP 137 A. Stepanov

Einstein coefficients for activation barriers of equilibrium and non-equilibrium
processes caused by

Plank radiation

CP 138 V. Fivet, E. Biemont, P. Palmeri, P. Quinet

New transition probabilities of astrophysical interest in triply ionized
lanthanum (La IV)

CP 139 J. Gurell, P. Lundin, S. Mannervik. L.O.Norlin, P. Royen

A new method for determining minute long lifetimes of metastable levels

CP 140 J. Gurell, P. Lundin, S. Mannervik. L.O.Norlin, P. Royen, P. Schef, H.
Hartman, A. Hibbert,

H. Lundberg, K. Blageov, P. Palmeri, P. Quinet, E. Biémont

Lifetime measurements of metastable states of astrophysical interest

CP 141 M.-T. Lee, M. Fujimoto, S. Michelin, I. Iga

Spin-exchange effects in elastic electron scattering from linear triatomic
radicals

CP 142 S. Zapryagaev, E.Butyrskaya

Spectral properties of interactions in endohedral fullerenes Li2@c60 and Na2@C60

CP 143 S. Zapryagaev, E.Butyrskaya

Simulation of fullerene formation

CP 144 I.I.Shafranyosh, M.I.Sukhoviya, M.I.Shafranyosh, R.O. Fedorko

Cross sections of negative ion poduction in electron collisions with Adenine
molecules

CP 145 O. Ryazanova, O. Nesterov, V. Zozulya

Effect of divalent metal ions on the conformational transitions in
poly(dA)+poly(dT) system

CP 146 K. Hubisz, T. Wroblewski, V.I. Tomin

Anomalous inhomogeneous broadening and kinetics properties of DMABN

CP 147 L. Pruvost, H. Jelassi, B. Viaris de Lesegno

Reexamination of the LeRoy-Bernstein formula for weakly bound molecules

CP 148 F. Talbi, M. Bouledroua, K. Alioua

The singlet X -A and X -B absorption coefficient of the K2 system

CP 149 A. W. Hauser, C. Callegari, W.E. Ernst, P. Soldán

Atomic-like shell models for alkali trimers derived from ab initio calculations

CP 150 L. Busevica, R. Ferber, O. Nikolayeva, E. Pazyuk, A. Stolyarov, M.
Tamanis

First observation and analysis of the (1; 2)1Π states of KCs

CP 151 O. Nikolayeva, R. Ferber, M. Tamanis, K. Knöckel, E. Tiemann, A. Pashov

High resolution spectroscopy and IPA potential construction of a3Σ+ state in KCs

245

CP 152 J. Heldt, M. Józefowicz. J. R. Heldt

Determination of first-order molecular hyperpolarizability of

ethyl 5-(4-aminophenyl)-3-amino-2,4-dicyanobenzoate using steady-state
spectroscopic

measurements and quantum-chemical calculations

CP 153 L.E. Sansores, J. Muniz, A. Martinez, R. Salcedo

Electronic structure of the [Au2(dmpm)(i - mnt)] complex

CP 154 T. L. Dimitrova, A. Weis

A lecture demonstration of quantum erasing on a photon by photon basis

CP 155 J.L. Robyr, P. Knowles, A. Weis

Stark shift in the Cs clock transition frequency

CP 156 P. Knowles, G. Bison, N. Castagna, A. Hofer, A. Mtechdlishvili, A.
Pazgalev, A. Weis

Magnetic Field Imaging With Arrays of Cs Magnetometers: Technology and
Applications

CP 157 R. Lammegger, L.Windholz

Performance of a compact dark state Magnetometer

CP 158 A. Litvinov, G. Kazakov, B. Matisov

Laser-induced transport effect and laser induced-line narrowing mechanism for
laser excitation in

87Rb atomic vapors in a finite-size buffer-less cell

CP 159 G.G. Grigoryan, G. Nikoghosyan, A. Gogyan, Y.T. Pashayan-Leroy, C. Leroy,
S. Guerin

Population transfer, light storage, and superluminal propagation by bright-state
adiabatic passage

CP 160 C. Andreeva, N. Bezuglov, A. Ekers, K. Miculis, B. Mahrov, I. Ryabtsev,
E. Saks,

R. Garcia-Fernandez, K. Bergmann

Population switching of Na and Na2 excited states by means of interference due
to Autler-Townes

effect

CP 161 E. Alipieva, E. Taskova, S. Gateva, G. Todorv

High-rank polarization moments influence on the CPT resonance obtained on
two-level degenerated

system

CP 162 K. Vaseva, P. Todorov, S. Caraleva, D. Slavov, S. Saltiel

Sub-Doppler fluorescence spectroscopy of Cs-vapour layers with nano-metric
thickness

CP 163 P. Todorov, S. Cartaleva, K. Vaseva, C. Andreeva, I. Maurin, D. Slavov,
S. Saltiel

Absorption in the saturation regime of Cs-vapour layer with thickness close to
the light wavelength

CP 164 M. Auzins, R. Ferber, I. Fescenko, L. Kalvans, M. Tamanis

Dark and bright resonances in large J systems

CP 165 M. Auzinsh, R. Ferber, F. Gahbauer, A. Jarmola, L. Kalvans

F-resolved bright and dark magneto-optical resonances at the cesium D1 line

CP 166 T. Kirova, A. Ekers, N. N. Bezuglov, I. I. Ryabtsev, K. Blushs, M.
Auzinsh

Effects of hyperfine structure on the Autler-Townes splitting

CP 167 A.Sargsyan, M.G. Bason, D. Sarkisyan, Y. Pashayan-Leroy, A.K. Mohapatra,
C.S. Adams

Ladder and lambda systems electromagnetically induced transparency in thin and
extremely-thin

cells

CP 168 A. Sargsyan, D. Sarkisyan, A. Papoyan,Y. Pashayan-Leroy, C.Leroy, P.
Moroshkin. A. Weis

Saturation effects of Faraday rotation signals in Cs vapor nanocells:
thickness-dependend effects

CP 169 L. Kalvans, M. Auzinsh, R. Ferber, F. Gahbauer, A. Jarmola, A. Papoyan,
D. Sarkisyan

Magneto-optical resonances in atomic rubidium at D1 excitation in ordinary and
extremely thin cells

CP 170 A.Y. Samokotin, A.V. Akimov, N.N. Kolachevsky, Y. V. Vladimirova, V.N.
Zadkov, A.V. Sokolov,

V. N. Sorokin

Frequency-modulation spectroscopy of coherent population trapping resonances

CP 171 K. Dahl, L. Spani, R.H. Rinkleff, K. Danzmann

Pump-probe spectroscopy: a survey of the spectra for four polarization
combintations in degenerate

two-level atoms

CP 172 Z. Grujic, M. Mijailovic, D. Arsenovic, M. Radonjic, B. M. Jelenkovic

Dark resonance narrowing in uncoated rubidium vacuum vapor cell

246

CP 173 S. S. Ivanov, P. Ivanov, N. Vitanov

Quantum search with trapped ions

CP 174 G. von Oppen

The observability of atoms

CP 175 T. Leveque, A. Gauguet, W. Chaibi, A. Landragin

Characterization of a high precision cold atom gyroscope

CP 176 F. Shojaei Baghini, M. A. Bolorizadeh, R. Fathi, E. Ganhbari Adivi

Electron capture of methane molecule by proton impact

CP 177 Ch.Berenguer, K. Katsonis, R. Srivastava, L. Sharma, R. Clarks, A.D.
Stauffer

Excitation of the Xe I 6s metastables to the 6p and 7p configurations

CP 178 G. P. Anisimova, E. Efremova, G. A. Tsygankova

Parametrization of Ne I spectrum for 2p55g, 6g, 7g configurations using
semiempirical method

CP 179 R. Karpuskiene, P. Bogdanovich, O. Rancova

Ab initio calculations of aluminium-like calcium

CP 180 T.J. Wasowicz, S. Werbowy, R. Drozdowski, J. Kwela

Isotope shifts of forbidden lines of Lead

CP 181 P. Moroshkin, V. Lebedev, A. Weis

Solid 4He stabilized by charged impurities below the solidification pressure of
pure helium

CP 182 P. Moroshkin, V. Lebedev, A. Weis

Spectroscopy of Ba atoms isolated in solid He matrix

CP 183 A. Matveev, J. Alnis, C. Parthey, N. Kolachevsky, T. W. Hänsch

New Measurement of the 2S Hyperfine Splitting in Atomic Hydrogen

CP 184 Yu.P. Gangrsky, K.P. Marinova, S.G. Zemlyanoi, M. Avogoulea, J. Billowes,
P. Campbell, B. Cheal,

B. Tordoff, M. Bissel, D.H. Forest, M. Gardner, G. Tungate, J. Huikari, H.
Penttila , J Aysto

High Resolution Laser Spectroscopy of Scandium

CP 185 S. Poonia

Lα1, Lα2, Lβ1, Lβ2 and Lγ satellites in the X-Ray emission spectra

CP 186 S. Poonia

Origin of X-Ray satellites spectra in the Lα1 and Lα2 region

CP 187 H.P. Garnir, E. Biemont, S. Enzonga Yoca, P. Quinet

VUV Spectroscopy of Xe IX

CP 188 V. Fivet, E. Biémont, P. Palmeri, P Quinet, L. Engström, H. Lundberg, H.
Nilsson

Improved atomic data for platinum group elements

CP 189 F. Gilleron, J. c. Pain, J. Bauche, C. Bauche-Arnoult

Impact of high-order moments on the statistical modeling of transition arrays

CP 190 J. C. Pain, F. Gilleron

Exact and statistical methods for computing the distribution of states, levels
and E1 lines in atomic

spectra

CP 191 Y.Nighat, R. Islam

Laser optogalvanic spectroscopy of Lanthanum in Spectral range of Rhodamine 6 G

CP 192 A. Nadeem

Investigation of the even parity states of group II-B elements (Zn, Cd and Hg)

CP 193 Z. Uddin, L. Windholz, F. Akber, M . Jahangir, I. Siddiqui

New levels of Pr I discovered via infrared spectral lines

CP 194 A. Er, I.K. Öztürk, Gö. Basar, S. Kroeger, Gü. Basar, A. Jarmola, M.
Tamanis, R. Ferber

New lines of atomic niobium in Fourier transform spectra

CP 195 J. Dembczynski, M. Elantkowska, J. Ruczkowski

Configuration interaction effects in the fine- and hyperfine structure of the
even configuration system

of tantalum atom

247

CP 196 E. Stachowska, J. Dembczynski, L. Windholz

Extended analysis of the even configurations of Ta II

CP 197 B. Furmann

Search for new electronic levels in singly ionized europium Eu II

CP 198 B. Acrimowicz, J. Dembczynski

Analysis of the odd configurations of tantalum atom search for configurations
containing f electrons

CP 199 J. Dembczynski, M. Elantkowska, J. Ruczkowski

Program package for semi-empirical analysis of the fine- and hyperfine structure
of complex atoms

CP 200 M. Elantkowska, J. Ruczkowski, J. Dembczynski

Procedure for precise determination of the hyperfine structure constants A, B, C
and D. Example of

lanthanum atom

CP 201 B. Gamper, L. Windholz

Investigations of the Hyperfinestructure of Praseodymium in the IR-Region with
the help of FTS

CP 202 P. Glowacki, L. Windholz, J. Dembczynski

Investigation of the hyperfine structure of Ta I - - lines

CP 203 I. Siddiqui, B. Gamper, G.H. Guthöhrlein, L.Windholz

Perturbed intensity distribution of hyperfine components of Praseodymium-I lines

CP 204 S. Khan, S.T. Iqbal, I. Siddiqui, L. Windholz

Investigation of the hyperfine structure of Pr I - lines in the region 5630 Å to
5772 Å

CP 205 G. Krois, G.H. Guthöhrlein, L. Windholz

Correction of Pr I energy level values due to Fourier transform spectra and
laser excitation

CP 206 H. Reschab, C. Cagran, R. Tanzer, W. Schützenhöfer, A. Graf, G.
Pottlacher

Normal spectral emissivity depending on atomic composition for two nickel-based
and two ferrousbased

alloys at 684.5 nm

CP 207 T. Hüpf, C. Cagran, G. Pottlacher, G. Lohöfer

Identification of atomic structure in measurement data, depending on the used
set of units

CP 208 S. Cohen, M. M. Harb, A. Ollagnier, S. Cohen, F. Lepine, F. Robicheaux,
M. Vrakking, C. Bordas

Electronic Wavefunction Microscopy using slow-photoelectron Imaging

CP 209 E. Dimova, D. Zhechev, V. Steflekova

On a self-sustained oscillating mode for operation of a glow discharge

CP 210 A. Kortyna and V. Fiore

Atomic beam measurements of the Cs 7d 2D3/2 hyperfne parameters with two-photon
fluorescence

spectroscopy

CP 211 O.B.Shpenik, E.E. Kontros, I.V. Chernyshova

Electron scattering by Cadmium atoms

CP 212 W. Steurer, B. Holst, J.R. Manson, W.E. Ernst

Probing surface vibrations of amorphous solids by helium atom scattering

CP 213 B. Brandstätter, B. Hemmerling, L. An der Lan, P.O. Schmidt

Towards Direct Frequency Comb Spectroscopy using Quantum Logic

CP 214 M. Niedermayr, M. Kumph, Piet Schmidt, Rainer Blatt

Towards Cryogenic Surface Ion Traps

CP 215 I. Iga, I. P. Sanches, R. T. Sugohara , M. G. P. Homem and M. T. Lee

Cross sections for elastic electron collisions with small alcohols

248

Author Index

Abad M CP 113

Abdoul R. CP 62

Acrimowicz B. CP 198

Adams C.s. CP 167

Adell J. CP 67

Agre M.Ya. CP 81

Akber F. CP 193

Akimov A. CP 61

Akimov A. CP 63

Akinov A.V. CP 170

Albéniz J. CP 135

Albert M CP 111

Alinejad N. CP 68

Alioua K. CP 103

Alioua K. CP 148

Alipieva E. CP 161

Allard O. CP 109

Allegrini M. CP 65

Allegrini M CP 66

Allouche A. CP 103

Alnis J. CP 183

Alnis J. CP 74

Alonso-Medina A. CP 70

Alonso-Medina A. CP 135

Amthor T. CP 84

Ancarani L.U. CP 9

Ancarani L.U. CP 15

Ancarani L.U. CP 26

Ancarani L.U. CP 27

An der Lahn L. CP 213

Andersson P. CP 42

Andreeva C. CP 107

Andreeva C. CP 160

Andreeva C. CP 163

Andreeva E.V. CP 24

Anisimova G.P. CP 88

Anismova G.P. CP 178

Arimondo E. CP 65

Arsenovic D. CP 172

Aspect A. CP 57

Atvars A. CP 89

Aubert-Frécon M. CP 103

Auböck G- CP 108

Auböck G. CP 109

Auböck G. CP 125

Auzinsh M. CP 89

Auzinsh M. CP 164

Auzinsh M. CP 165

Auzinsh M. CP 166

Auzinsh M CP 169

Avgoulea M. CP 184

Aymar M. CP 3

Aysto J. CP 184

Azima A. CP 100

Baig M.A. CP 76

Ban T. CP 94

Banás D. CP 43

Bandi T.N. CP 7

Bandurina L. CP 44

Barillaro G. CP 66

Barker P.F. PR 6

Basar Gü. CP 194

Basar Gö. CP 194

Bason M.G. CP 167

Bassu M. CP 66

Baszanowska E. CP 45

Batteiger V. CP 116

Bauche J. CP 189

Bauche-Arnoult C. CP 189

Beaufils Q. CP 53

Becker Th. CP 8

Becker U. PR 4

Beil F. CP 120

Bendkowsky V. CP 122

Bengtsson J. CP 12

Bengtsson J. CP 25

Beninger M. CP 1

Benseddik C. CP 49

Berenguer Ch. CP 131

Berenguer Ch. CP 177

Bergmann K. CP 160

Berset M CP 43

Beterov I.I. CP 51

Beterov I.I. CP 85

Beterov I.I. CP 106

Beterov I.I. CP 126

Bezuglov N.N. CP 84

Bezuglov N.N. CP 85

Bezuglov N.N. CP 106

Bezuglov N.N. CP 107

Bezuglov N. CP 160

Bezuglov N.N. CP 166

Biémont E. CP 132

Biémont E. CP 138

Biémont E. CP 140

Biémont E. CP 187

Biémont E. CP 188

Bieron J. CP 11

Billowes J. CP 184

Bison G. CP 156

Bissel M. CP 184

Blagoev K. CP 132

Blagoev K. CP 140

Blatt R. CP 214

Blaum K. CP 6

Blaum K. CP 69

Blaum K. CP 123

Blondel C. PL 9

Blondel C. CP 71

Blushs K. CP 166

Bogdanovic P. CP 21

Bogdanovic P. CP 179

Bolorizadeh M.A. CP 28

Bolorizadeh M.A. CP 176

Bordas C. CP 208

Bouazza M.T. CP 49

Bouazza M.T. CP 50

249

Bouchene M.A. CP 121

Bouledroua M. CP 49

Bouledroua M. CP 50

Bouledroua M. CP 103

Bouledroua M. CP 104

Bouledroua M. CP 105

Bouledroua M. CP 148

Bourdel T. CP 57

Bouyer P. CP 57

Brandstätter B. CP 213

Brantut J.P. CP 57

Brescansin L.M. CP 33

Breschi E. CP 119

Bruvelis M. CP 107

Busevica L. CP 150

Butscher B. CP 122

Butyrskaya E.V. CP 142

Butyrskaya E.V. CP 143

Bylicki M. CP 95

Cagran C. CP 206

Cagran C. CP 207

Callegari C. CP 108

Callegari C. CP 109

Callegari C. CP 125

Callegari C. CP 149

Campbell P. CP 184

Carette T. CP 71

Cartaleva S. CP 162

Cartaleva S CP 163

Casa G. CP 115

Castagna N. CP 156

Castrillo A. CP 115

Cerè A. CP 113

Chaeal B. CP 184

Chaibi W.E. CP 175

Chaibi W. PL 9

Champenois C. PR 2

Champion C. CP 34

Chebakov K. CP 61

Chelli S. CP 104

Chernushkin V.V. CP 91

Chernyshova I.V. CP 211

Chicireanu R. CP 53

Chmielewska D. CP 43

Chwirot S. CP 48

Clark R.E.H. CP 131

Clark R.E.H. CP 177

Clément J.F. CP 57

Cohen S. CP 208

Colavecchia F.D. CP 27

Colón C. CP 135

Colón C. CP 70

Corkum P. PL 10

Cornille M. CP 131

Costello J.T. CP 100

Costescu A. CP 97

Crespo Lopez-U. J.R. PR 7

Crubellier A. CP 53

Cubaynes D. CP 100

Curl R.F., jr. EL 1

Czarnota M. CP 43

Dahl K. CP 171

Dal Cappello C. CP 27

Dal Cappello C. CP 34

Dantan A. CP 111

Danzmann K. CP 171

Dardis J. CP 100

de St. Vincent M.R. CP 57

Deiglmayr J. CP 3

Delsart C. CP 71

Delsart C. PL 9

Dembczynski J. CP 195

Dembczynski J. CP 196

Dembczynski J. CP 198

Dembczynski J. CP 199

Dembczynski J. CP 200

Dembczynski J. CP 202

Denskat J. CP 84

Desouter-Lecomte M. CP 37

di Serafino D. CP 115

Diehl Ch. CP 6

Diehl C. CP 42

Diehl Ch. CP 69

Dimitrova T.L. CP 154

Dimova E. CP 209

Diry F. CP 52

Dmitriev S.P. CP 46

Dousse J.Cl. CP 43

Dovator N.A. CP 46

Drag C. CP 71

Drag C. PL 9

Drewsen M. CP 111

Drewsen M. CP 117

Drozdowski R. CP 45

Drozdowski R. CP 180

Dsterer S. CP 100

Dubrovskaya Yu.V. CP 127

Dubrovskaya Yu.V. CP 130

Dulieu O. CP 3

Dzhurakhalov A.A. CP29

Dziczek D. CP 48

Efremova E.A. CP 88

Efremova E.A. CP 178

Egorov M. CP 63

Ehresmann A. CP 20

Eiguren A. CP 112

Ekers A. CP 84

Ekers A. CP 85

Ekers A. CP 106

Ekers A. CP 107

Ekers A. CP 160

Ekers A. CP 166

Elantowska M. CP 195

Elantowska M. CP 199

Elantowska M. CP 200

Engström L. CP 132

Engström L. CP 188

Entin V.M. CP 51

Entin V.M. CP 85

Entin V.M. CP 126

250

Enzonga Yoca S. CP 187

Epp S.W. PR 7

Er A. CP 194

Erbert G. CP 5

Ernst W.E. CP 108

Ernst W.E. CP 109

Ernst W.E. CP 125

Ernst W.E. CP 149

Ernst W.E. CP 212

Fathi R. CP 28

Fathi R. CP 176

Fedorko R.O. CP 144

Fedorko R.O. CP 31

Feldhaus J. CP 100

Ferber R. CP 150

Ferber R. CP 151

Ferber R. CP 164

Ferber R. CP 165

Ferber R. CP 169

Ferber R. CP 194

Ferlaino F. CP 1

Fescenko I. CP 164

Fiore V. CP 210

Fivet V. CP 138

Fivet V. CP 188

Forest D.H. CP 184

Forstner O. CP 42

Fritzsche S. CP 11

Froese Fischer C. CP 71

Fröhlich B. CP 60

Fujimoto M.M CP 141

Furmann B. CP 197

Fuso F. CP 65

Fuso F. CP 66

Gahbauer F. CP 165

Gahbauer f. CP 169

Gaidamauskas E. CP 10

Gaidamauskas E. CP 11

Gaigalas G. CP 10

Gaigalas G. CP 11

Galzerano G. CP 115

Gamper B. CP 201

Gamper B. CP 203

Gangersky Yu.P. CP 184

Garcia-Fernandez R. CP 160

Gardner M. CP 184

Garnir H.P. CP 187

Gartman R. CP 62

Gartman R. CP 64

Gasaneo G. CP 9

Gasaneo G. CP 15

Gasaneo G. CP 26

Gasaneo G. CP 27

Gateva S. CP 161

Gauguet A. CP 175

Gawlik W. CP 62

Gawlik W. CP 64

Gedeon S. CP 36

Gedeon V. CP 44

Germann Th. CP 8

Ghanbari Adivi E. CP 28

Ghanbari Adivi E. CP 176

Giafrani L. CP 115

Giese C. CP 84

Gilleron F. CP 189

Gilleron F. CP 190

Glazov D.A. CP 22

Glazov D.A. CP 90

Gleeson D. CP 77

Glijer D. CP 100

Glowacki P. CP 202

Glukhov I.L. CP 82

Glushkov A.V. CP 17

Glushkov A.V. CP 18

Glushkov A.V. CP 73

Glushkov A.V. CP 127

Glushkov A.V. CP 128

Glushkov A.V. CP 130

Gochitashvili M. CP 30

Godefroid M. CP 71

Gogyan A. CP 159

Gomonai A. CP 41

Gonzalez V.Y. CP 15

Gonzalez V.Y. CP 9

Gorceix O. CP 53

Gorceix O. CP 59

Graf A. CP 206

Griesmaier A. CP 60

Grigoryan G.G. CP 79

Grigoryan G.G. CP 159

Grimm R. CP 1

Grimm R. PR 5

Grond J. CP 55

Grujic Z. CP 172

Gudym V.K. CP 24

Guérin S. CP 159

Guérin S. CP 79

Gupta G.P. CP 133

Gupta G.P. CP 134

Gurell J. CP 139

Gurell J. CP 140

Gurnitskaya E.P. CP 130

Guthöhrlein G.H. CP 203

Guthöhrlein G.H. CP 205

Hagel G. PR 2

Hakhumyan G. CP 89

Halfmann T. CP 120

Hänsch T.W. CP 8

Hänsch T.W. CP 74

Hänsch T.W. CP 116

Hänsch T.W. CP 183

Hanstorp D. CP 42

Harb M.M. CP 208

Haroche S. PL 1

Hartman H. CP 140

Hashmi F.A. CP 121

Hauser A.W. CP 109

Hauser A.W. CP 149

Hayden P. CP 100

Hecker-Denschlag J. PR 5

251

Hefferlin R. CP 110

Heidemann R. CP 122

Heldt J. CP 152

Heldt J.R. CP 152

Hemmerling B. CP 213

Herrán-Martínez C. CP 70

Herrmann M. CP 116

Herskind P. CP 111

Heubrandtner Th. CP 96

Hibbert A. CP 140

Hinds E.A. CP 112

Hitawala U. CP 38

Hofer A. PL 6

Hofer A. PL 6

Hohenester U. CP 54

Hohenester U. CP 55

Hohenester U. CP 112

Hojbjerre K. CP 117

Holst B. CP 212

Homem M.G.P. CP 215

Hoszowska J. CP 43

Hotop H. CP 101

Houamer S. CP 34

Hough P. CP 100

Houssin M. PR 2

Hubisz K. CP 146

Huikari J. CP 184

Hüpf Th. CP 207

Hussain S.Q. CP 76

Hutych Yu. CP 41

Iga I. CP 33

Iga I. CP 141

Iga I. CP 215

Ilinova E.Yu. CP 83

Ilver L. CP 67

Imre A. CP 41

Islam R. CP 191

Ivanov S. CP 173

Ivanov P. CP 173

Izadi F. CP 68

Jahangiri M. CP 68

Jahangir M CP 193

Jarmola A. CP 165

Jarmola A. CP 169

Jarmola A. CP 194

Jelassi H. CP 2

Jelassi H. CP 147

Jelenkovic B.M CP 172

Jiang D. CP 13

Johnson W.R. CP 14

Jönsson P. CP 11

Józefowicz M. CP 152

Jursenas R. CP 23

Kabachnik N.M. CP 72

Kalvans L. CP 164

Kalvans L. CP 165

Kalvans L. CP 169

Kamenski A.A. CP 92

Kaminski P. CP 45

Kanorsky S. CP 61

Kanski J. CP 67

Karpuskiene R. CP 21

Karpuskiene R. CP 179

Kartoshkin V.A. CP 46

Kartoshkin V.A. CP 47

Kashuba A.S. CP 35

Katsonis K. CP 131

Katsonis K. CP 177

Kazakov G. CP 119

Kazakov G. CP 158

Kazansky A.K. CP 72

Keller J.C. CP 53

Keller J.C CP 59

Kennedy E.T. CP 100

Khabibullaev P.K. CP 78

Khan Sh. CP 204

Khanna F.C. CP 78

Khetselius O.Yu. CP 16

Khetselius O.Yu. CP 17

Khetselius O.Yu. CP 73

Khetselius O.Yu. CP 127

Khetselius O.Yu. CP 129

Khetselius O.Yu. CP 130

Kienberger R. PR 9

Kirova T. CP 166

Klein J. CP 120

Klosowski L. CP 48

Kluge H.-J. PL 3

Klumpp S. CP 20

Knöckel K. CP 151

Knöckl H. CP 58

Knoop S. CP 1

Knoop M. PR 2

Knowles P. CP 155

Knowles P. CP 156

Knünz S. CP 116

Koch M. CP 125

Koch T. CP 60

Kolachevsky N. CP 61

Kolachevsky N. CP 63

Kolachevsky N. CP 74

Kolachevsky N. CP 170

Kolachevsky N. CP 183

Kontros E.E. CP 211

Koperski J. CP 114

Kortyna A. CP 210

Kozhedub Y.S. CP 22

Kozlov M.G. CP 14

Kracke H. CP 123

Kreim S. CP 123

Kröger S. CP 194

Krois G. CP 205

Kronfeldt H.D. CP 5

Kronfeldt H.D. CP 75

Krosnicki M. CP 114

Kumph M. CP 214

Kuparashvili D. CP 30

Kurskov S.Yu. CP 35

Kwela J. CP 180

Kwela J. CP 87

252

Laburthe-Tolra B. CP 53

Laburthe-Tolra B. CP 59

Lagutin B.M. CP 20

Lahaye Th. CP 60

Lammegger R. CP 119

Lammegger R. CP 157

Landragin A. CP 175

Lang F. PR 5

Langkilde-Lauesen M.B. CP 111

Lanzersdorfer J. CP 125

Laporta P. CP 115

Lazur V. CP 36

Lebedev V. PL 6

Lebedev V. CP 181

Lebedev V. CP 182

Lee M.T. CP 33

Lee M.T. CP 141

Lee M.T. CP 215

Leino M. CP 124

Lépine F. CP 208

Leroy C. CP 159

Leroy C. CP 168

Leroy C. CP 79

Leveque T. CP 175

Li W. CP 100

Lindahl A.O. CP 42

Lindroth E. CP 12

Lindroth E. CP 25

Lisdat Chr. CP 58

Litvinov A. CP 158

Liu S. CP 58

Loboda A.V. CP 73

Lohöfer G. CP 207

Lomsadze R. CP 30

Lomsadze B. CP 30

Loreau J. CP 37

Löw R. CP 122

Lundberg H. CP 132

Lundberg H. CP 140

Lundberg H. CP 188

Lundin P. CP 139

Lundin P. CP 140

Machado L.E. CP 33

Mahrov B. CP 107

Mahrov B. CP 160

Maillard Y.P. CP 43

Maiwald M. CP 5

Malcheva G. CP 132

Malinovskaya S.V. CP 127

Manakov N.L. CP 98

Manakov N.L. CP 99

Mangasuli V. CP 65

Mannervik S. CP 139

Manson J.R. CP 212

Mannervik S. CP 140

Maréchal E. CP 53

Maréchal E. CP 59

Marinova K.P. CP 184

Mark M. CP 1

Marler J. CP 111

Marmo S.I. CP 98

Marmo S.I. CP 99

Martinez A. CP 153

Marushka V.I. CP 31

Matisov B. CP 119

Matisov B. CP 158

Matrasulov D.U. CP 78

Matveev A. CP 74

Matveev A. CP 183

Matveeva N.A. CP 118

Maurin I. CP 163

Mauritsson J. PR 10

Mauron O. CP 43

Mayo R. CP 132

Mazets I.E. CP 56

Melezhik V.S. CP 40

Melnikov L.A. CP 93

Merlone A. CP 115

Mestre M. CP 52

Metz J. CP 60

Meyer M. CP 100

Michelin S.E. CP 141

Miculis K. CP 84

Miculis K. CP 106

Miculis K. CP 107

Miculis K. CP 160

Mijailovic M CP 172

Mileti G. CP 119

Minogin V. CP 7

Minogin V. CP 77

Mitchell M.W. CP 113

Mitnik D.M. CP 15

Mitnik D.M CP 9

Mohapatra A.K. CP 167

Mooser A. CP 123

Moroshkin P. PL 6

Moroshkin P. CP 168

Moroshkin P. CP 181

Moroshkin P. CP 182

Motsch M. CP 4

Motsch M. CP 80

Msezane A.Z. CP 134

Mtchedlishvili A. CP 156

Muniz J. CP 153

Musso M. CP 96

Nadeem A. CP 192

Nägerl H.C. CP 1

Nagl J. CP 108

Nagl J. CP 109

Nagl J. CP 125

Nesterov O. CP 145

Nic Chormaic S. CP 7

Nic Chormaic S. CP 77

Niedermayr M. CP 214

Nighat Y. CP 191

Nikoghosyan G. CP 159

Nikolayeva O. CP 150

Nikolayeva O. CP 151

Nilsson H. CP 132

Nilsson H. CP 188

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Norlin L.O. CP 139

Norlin L.O. CP 140

Nyman R.A. CP 57

Ollagnier A. CP 208

Ortiz M. CP 132

Otajanov D.M. CP 78

Ovcharenko E. CP 41

Ovsiannikov V.D. CP 82

Ovsiannikov V.D. CP 83

Ovsiannikov V.D. CP 91

Ovsiannikov V.D. CP 92

Ozawa A. CP 116

Öztürk I.K. CP 194

Pain J.C. CP 189

Pain J.c. CP 190

Pajek M. CP 43

Pal R. CP 13

Palmeri P. CP 138

Palmeri P, CP 140

Palmeri P. CP 188

Papoyan A. CP 168

Papoyan A. CP 89

Papoyan A. CP 169

Parigi V. CP 113

Parthey C. CP 74

Parthey C. CP 183

Pashayan-Leroy Y.T. CP 79

Pashayan-Leroy Y.T. CP 159

Pashayan-Leroy Y.T. CP 167

Pashayan-Leroy Y.T. CP 168

Pashov A. CP 151

Pawlak M. CP 95

Pazgalev A. CP 156

Pazyuk E.A. CP 150

Pegg D.J. CP 42

Penttila H. CP 184

Perehanets V.V. CP 31

Petrov I.D. CP 20

Petrov I.D. CP 101

Pfanner G. CP 54

Pfau T. CP 60

Pfau T. CP 122

Pichler G. CP 94

Pinegar D. CP 6

Pinegar D. CP 69

Pinkse P.W.H. CP 4

Pinkse P.W.H. CP 80

Piwinski M. CP 48

Pleskacz K. CP 48

Plunien G. CP 22

Plunien G. CP 90

Polasik M CP 43

Poonia S. CP 185

Poonia S. CP 186

Popov Y. CP 34

Porfido N. CP 65

Pottlacher G. CP 206

Pottlacher G. CP 207

Predojevic A. CP 113

Prescimone F. CP 65

Pruvost L. CP 2

Pruvost L. CP 52

Pruvost P. CP 147

Purohit G. CP 38

Quack M. PL 2

Quinet P. CP 132

Quinet P. CP 138

Quinet P. CP 140

Quinet P. CP 187

Quinet P. CP 188

Quint W.H. CP 123

Raboud P.A. CP 43

Radonjic M CP 172

Raitzsch U. CP 122

Rakhimov Kh.Yu CP 19

Rancova O. CP 21

Rancova O. CP 179

Redlin H.. CP 100

Reggami L. CP 105

Rempe G. CP 4

Rempe G. CP 80

Reschab H. CP 206

Resmej F. CP 37

Richardson V. CP 100

Richter M. PR 3

Riehle F. PL 5

Rinkleff R.H. CP 171

Robicheaux F. CP 208

Robyr J.L. CP 155

Rodegheri C. CP 123

Rodionov P. CP 61

Rodriguez K.V. CP 9

Rodriguez K.V. CP 15

Rössl E. CP 96

Royen P. CP 139

Royen P. CP 140

Ruczkowski J. CP 195

Ruczkowski J. CP 199

Ruczkowski J. CP 200

Rudzikas Z. CP 10

Ruiz J. CP 132

Ruzmetov T.A. CP 78

Ryabinina M.V. CP 93

Ryabtsev I.I. CP 51

Ryabtsev I.I. CP 85

Ryabtsev I.I. CP 126

Ryabtsev I.I. CP 160

Ryabtsev I.I. CP 166

Ryazanova O. CP 145

Rzadkiewicz J. CP 43

Saathoff G. CP 116

Sadowski J. CP 67

Saeidian S. CP 40

Safronova M. CP 13

Safronova M. CP 14

Safronova Ul. CP 13

Saidov A.A. CP 78

Saks E. CP 106

Saks E. CP 107

Saks E. CP 160

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Salcedo R. CP 153

Saleem M. CP 76

Saltiel s. CP 162

Saltiel S. CP 163

Samokotin A.Yu. CP 170

Sanches I.P. CP 215

Sansores L.E. CP 153

Sargsyan A. CP 167

Sargsyan A. CP 168

Sarkisyan D. CP 89

Sarkisyan D. CP 167

Sarkisyan D. CP 168

Sarkisyan D. CP 169

Scharf O. CP 71

Schartner K.H. CP 20

Scheel S. CP 112

Schef P. CP 140

Schenk M. CP 4

Schmelcher P. CP 40

Schmidt H. CP 5

Schmidt H. CP 75

Schmidt P.O. CP 213

Schmidt P.O. CP 214

Schmiedmayr J. PL 4

Schmiedmayer J. CP 55

Schmiedmayer J. CP 56

Schmoranzer H. CP 20

Schnizer B. CP 96

Schöbel H. CP 1

Schuessler H. CP 116

Schumm T. CP 56

Schützenhöfer W CP 206

Scrinzi A. PL 11

Scully M.O. PL 7

Seliger M. CP 54

Selsto S. CP 12

Selsto S. CP 25

Semczuk M. CP 116

Semenov R.I. CP 88

Shabaev V.M. CP 22

Shabaev V.M. CP 90

Shafranyosh I.I. CP 31

Shafranyosh I.I. CP 144

Shafranyosh M.I. CP 144

Sharma L. CP 131

Sharma L. CP 177

Sherstov I. CP 58

Shojaei Baghini F. CP 28

Shojaei Baghini F. CP 176

Shpenik O.B. CP 32

Shpenik O.B. CP 211

Siddiqui I. CP 193

Siddiqui I. CP 203

Siddiqui I. CP 204

Skolnik G. CP 94

Slavov D: CP 162

Slavov D. CP 163

Snegurskaya T.A. CP 31

Sokolov A. CP 63

Sokolov A.V. CP 170

Soldán P. CP 149

Sommer Ch. CP 4

Sorokin A.A. PR 3

Sorokin V. CP 61

Sorokin V. CP 63

Sorokin V.N CP 170

Spani Molella L. CP 171

Spanulescu S. CP 97

Srivastava R. CP 131

Srivastava R. CP 177

Staanum P.F. CP 117

Stabkowska K. CP 43

Stachowska E. CP 196

Stania G. CP 8

Stauffer A.D. CP 131

Stauffer A.D. CP 177

Steflekova V. CP 209

Stepanov A. CP 137

Stetsovych V.V. CP 31

Steurer W. CP 212

Stoica C. CP 97

Stolyarov A.V. CP 150

Strambini L. CP 66

Strauss c. PR 5

Strojecki M. CP 114

Sud K.K. CP 38

Sugohara R.T. CP 215

Sujkowski Z. CP 43

Sukharev D.E. CP 130

Sukhorukov V.L. PR 8

Sukhorukov V.L. CP 20

Sukhorukov V.L. CP 101

Sukhoviya M.l CP 144

Sumpf B. CP 5

Svanberg S. CP 132

Svinarenko A.A. CP 17

Sviridov S.A. CP 98

Sviridov S.A. CP 99

Sydoryk I. CP 106

Syty P. CP 39

Szczepkowski J. CP 62

Szczepkowski J. CP 64

Taichenachev A.V. CP 118

Talbi F. CP 148

Tamanis M. CP 150

Tamanis M. CP 151

Tamanis M. CP 164

Tamanis M. CP 194

Tantussi F. CP 65

Tantussi F. CP 66

Tanweer Iqbal S. CP 204

Tanzer R. CP 206

Taskova E. CP 161

Tereschenko E. CP 63

Thoumany P. CP 8

Tiemann E. CP 58

Tiemann E. CP 151

Tino G.M. PL 8

Todorov G. CP 161

Todorov P. CP 162

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Todorov P. CP 163

Tolstikhina I. CP 61

Tomin V.I. CP 146

Tordoff B. CP 184

Torosov B.T. CP 86

Träbert E. CP 136

Tränkle G. CP 5

Tretyakov D.B. CP 51

Tretyakov D.B. CP 85

Tretyakov D.B. CP 126

Tsiskarishvili N.A. CP 30

Tsygankova G.A. CP 88

Tsygankova G.A CP 178

Tumaikin A.M. CP 118

Tungate G. CP 184

Tupitsyn I.I. CP 22

Tupitsyn I.I. CP 90

Uddin Z. CP 193

Udem Th. CP 116

Ulfat I. CP 67

Ullrich J. PR 7

Ulmer S. CP 123

Umarov F.F. CP 29

Urbonas L. CP 8

Vaeck N. CP 37

van Buuren L. CP 4

van Dyck R. CP 6

van Dyck R.S. CP 69

Varoquaux G. CP 57

Vaseva K. CP 162

Vaseva K. CP 163

Vdovic S. CP 94

Vedel F. PR 2

Vernac L. CP 53

Vernac L. CP 59

Vernakelen A. CP 116

Viaris de Lesegno B. CP 2

Viaris de Lesegno B. CP 52

Viaris de Lesegno B. CP 147

Viel A. CP 124

Vitanov N. CP 173

Vitanov N.V. CP 86

Vladimirova Yu.V. CP 170

Volotka A.V. CP 90

von Oppen G. CP 45

von Oppen G. CP 174

Vrakking M CP 208

Vujicic N. CP 94

Walz J. CP 123

Wasowicz T.J. CP 180

Wehr R. CP 115

Weidemüller M. CP 84

Weis A. PL 6

Weis A. CP 154

Weis A. CP 155

Weis A. CP 156

Weis A. CP 168

Weis A. CP 181

Weis A. CP 182

Wendt K. CP 42

Werbowy S. CP 87

Werbowy S. CP 180

Werner L. CP 20

Wester R. PR 1

Wester R. CP 117

Windholz L. CP 119

Windholz L. CP 157

Windholz L. CP 193

Windholz L. CP 196

Windholz L. CP 201

Windholz L. CP 202

Windholz L. CP 203

Windholz L. CP 204

Windholz L. CP 205

Winkler K. PR 5

Witkowski M. CP 62

Witkowski M. CP 64

Wolframm F. CP 113

Wróblewski T. CP 146

Yousif Al-Mula S.Y. CP 102

Yudin V.I. CP 118

Zachorowski J. CP 62

Zadkov V.N CP 170

Zanon T. CP 53

Zanón A. CP 135

Zapryagaev S.A. CP 142

Zapryagaev S.A. CP 143

Zavilopulo A.N. CP 32

Zawada M. CP 62

Zawada M. CP 64

Zemlyanoi S.G. CP 184

Zeppenfeld M. CP 80

Zhechev D. CP 209

Zhu F. CP 116

Zillich R.E. CP 124

Zozulya V. CP 145

Zumsteg C. PR 2

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