Del Mar Photonics - Newsletter

We develop and supply radiographic systems, based on portable neutron generators and two-coordinate image detectors, in compliance with technical requirements, specified by a customer under the condition that they can be realized. When a customer is not able to formulate technical requirements for the system, it is necessary to give the detailed description of the sample to be analyzed (dimensions, chemical composition, type and size of defects under control, etc.) and formulate the tasks of radiographic control.

Neutron Radiography - request a quote

Read this first: US NRC regulations require that buyers have a Type A Broadscope specific license authorizing possession of tritium in the applicable quantities before purchase of tritium neutron generators or you must apply for an engineering safety sealed source and device (SS&D) review and have a specific license authorizing the possession of these devices. Visit U.S. Nuclear Regulatory Commission (NRC) website for details.

Several Non-Power Reactors provide Neutron Radiography services. Del Mar Ventures develop and supply customized fast neutron radiography systems based on neutron generators. Ask us about opportunity to use one of them for your applications.

Neutron sources

The ING-07 is a generator with a Penning type ion source and the ING-103 - with a plasma focus tube. Specifications of the generators are presented in Table 1. Fast (14MeV) neutrons are emitted in 4p steradian. Maximum neutron yield amounts to about 3x10⁹ n/s for the ING-07 and 3x10¹⁰ n/pulse for the ING-103. It is important to notice that the generators emit fast neutrons out of a small area. Its size is about 3-5 mm and 1 mm for ING-07 and ING-103, respectively. Thus, in most practical cases these sources can be considered as point like ones. A short duration of the ING-103 pulse (20 ns) and rather high neutron yield per pulse are especially of interest for imaging quick processes. Besides fast neutrons the generators radiate also X-rays with an average energy of about 80 keV.

A low power consumption and dimensions of the generators are very attractive from the point of view of their use in industry for on site inspection.

Table 1.

Position-Sensitive (Imaging) Detector of Neutron

Radiographic images obtained by detection of luminescence generated by neutrons passing Gd-doped screen with a CCD detector. The entrance of the detector has diam 150 mm field of view. The fast neutron screen made of a composite material consisting of an organic resin and a powder luminophore (Gd₂O₂S: Tb). A thickness of the screen is 3 mm.

Due to presence of a powder luminophore in the screen the detector is sensitive also to X-rays. The measurement of intensities of the signals produced by fast neutrons and accompanying X-rays in the CCD-detector placed at a distance of 15 cm from a generator showed that these signals are in a 1:5 and 1:1 ratio for ING-07 and ING-103, respectively. A ratio of signals produced by fast neutrons and by X-ray is changeable by shielding the source with a lead screen of an appropriate thickness.
More details about Gd-screen detectors and imaging systems can be found here.

         Scheme of neutron CCD-detector design

1 - CCD-matrix, 2 - lens system, 3 - mirror, 4 - luminescent screen 
5 - sample, 6 - image intensifier

Fast Neutron Radiography System Specifications

irradiation area: up to 30x30 cm²
L/D value: 10 - 100
exposure time: 1 - 10 min
 

Fast Neutron Radiography Facility Requirements

US NRC regulations require that buyers have a Type A Broadscope specific license authorizing possession of tritium in the applicable quantities before purchase of tritium neutron generators or you must apply for an engineering safety sealed source and device (SS&D) review and have a specific license authorizing the possession of these devices. Visit U.S. Nuclear Regulatory Commission (NRC) website for details.

Fast Neutron Radiography Images

Image 1. BNC-connector

Image 2. Rele

Image 3. Al-Si alloy
 

Image 4. Asphalt particle

Neutron Radiography - request a quote