3 October 2016 GAMBE: multipurpose sandwich detector for neutrons and photons
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Detectors made with semiconductors such as silicon can be efficiently used for detecting and imaging neutrons when coated with suitable materials. They detect the charged reaction products resulting from the interaction of thermal neutrons with materials with high capture cross section like 10B, 6Li, and 6LiF. This work describes the performance of a thermal neutron detector system, GAMBE, which is based on silicon sensors and a layer of neutron-sensitive material, such as a lithium fluoride film or a lithium-6 foil, in a sandwich configuration. This arrangement has a total detection efficiency of 4 ± 2 %, 7 ± 1 %, and12 ± 1 % for 7 μm 6LiF film, 40 μm and 70 μm 6Li foil respectively. Also, it enhances the rejection of fake hits using a simple coincidence method. The coincidence that defines a true neutron hit is the simultaneous signal recorded by the two sensors facing the conversion layer (or foil). These coincidences provide a very good method for rejecting the spurious hits coming from gamma-rays, which are usually present in the neutron field under measurement. The GAMBE system yields a rejection factor at the level of 108 allowing very pure neutron detection in high gamma background conditions. However, the price to pay is a reduction of the detection efficiency of 1 ± 1 % or 0:9 ± 0:3 % for 7 μm 6LiF film and 40 μm 6Li foil respectively.
Conference Presentation
© (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
A. Ahmed, A. Ahmed, S. Burdin, S. Burdin, G. Casse, G. Casse, H. van Zalinge, H. van Zalinge, S. Powel, S. Powel, J. Rees, J. Rees, A. Smith, A. Smith, I. Tsurin, I. Tsurin, } "GAMBE: multipurpose sandwich detector for neutrons and photons", Proc. SPIE 9969, Radiation Detectors: Systems and Applications XVII, 99690E (3 October 2016); doi: 10.1117/12.2236752; https://doi.org/10.1117/12.2236752

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