Device for Detection of Explosives, Nuclear and Other Hazardous Materials in Luggage and Cargo Containers

摘要

Device for detection of explosives, radioactive and heavily shielded nuclear materials in luggage and cargo Containers based on Nanosecond Neutron Analysis / Associated Particles Technique (NNA/APT) is under construction. Detection module consists of a small neutron generator with built-in positionsensitive detector of associated alpha-particles, and several scintillator-based gamma-ray detectors. Explosives and other hazardous chemicals are detected by analyzing secondary high-energy gamma-rays from reactions of fast neutrons with materials inside a Container. The same gamma-ray detectors are used to detect unshielded radioactive and nuclear materials. An array of several neutron detectors is used to detect fast neutrons from induced fission of nuclear materials. Coincidence and timing analysis allows one to discriminate between fission neutrons and scattered probing neutrons. Mathematical modeling by MCNP5 and MCNP-PoliMi codes was used to estimate the sensitivity of the device and its optimal configuration. Comparison of the features of three gamma detector types - based on BGO, NaI and LaBr_3 crystals is presented.