Pulsed Photonuclear Assessment (PPA) Technology Enhancement Study

Idaho National Laboratory

关键词: Radiation Detectors;    46 Instrumentation Related To Nuclear Science And Technology;    Photons;    Shielding;    43 Particle Accelerators;   

DOI  :  10.2172/911807
RP-ID  :  INL/EXT-06-11175
RP-ID  :  DE-AC07-99ID-13727
RP-ID  :  911807

美国|英语

来源: UNT Digital Library

【 摘 要 】

The Idaho National Laboratory (INL) along with the Los Alamos National Laboratory (LANL) and Idaho State University’s Idaho Accelerator Center (IAC) has designed and tested a nominal 10-MeV prototype Pulsed Photonuclear Assessment (PPA) inspection system to detect shielded nuclear material. This report highlights two specific areas that will provide further PPA technology enhancements, namely, an optimal gamma-ray detection system and the off axis radiation detection sensitivity. Detection of low-atomic number (Z) shielded nuclear material had been initially addressed by the inclusion of dedicated Geiger-Müller (GM) detectors co-located above each of the Photonuclear Neutron Detectors (PNDs). Several different radiation detectors were investigated to assess if this type of gamma-ray detector was optimal. The LND 719 GM detector was shown to have the best photon sensitivity and demonstrated an optimal ability to detect low-Z shielded nuclear material. Beyond the technical performance of this detector, its low cost and availability makes it a logical choice for a field-deployable system. In terms of off-axis detection sensitivity, simulation and benchmarking experiments have indicated that the PPA inspection system can successfully detect nuclear material (within 120 seconds) in various shielding configurations even when it is located at a distance of as much as 30 cm off the interrogating beam axis (the exact sensitivity to off-axis interrogations will be largely dependent on the actual shielding material). As a general rule, high-Z shielding will allow detection at larger off-axis distances than low-Z materials.