Development of a compact neutron capture gamma-ray imaging system for anti-personnel landmine detection

An advanced neutron capture gamma-ray imaging system has been developed for detection and localization of anti-personnel landmines (APMs). The system consists of an improved Cockcroft-Walton type accelerator neutron source using DD fusion reaction and a compact high energy gamma camera based on stacked bismuth-germanium-oxide (BGO) scintillator rods to deduce the incident direction of characteristic gamma-rays from nitrogen included in landmines. In the performance tests with landmine imitators in a mock-up soil assembly, we demonstrated that this system could detect and locate an a APM of 100 g cyclo-trimethylenetrinitramine (RDX) and/or trinitrotoluene (TNT) explosive buried at a depth of 5 cm with the spatial resolution around 10 cm in a 1 m square area within 10 min and also those at 10 or 15 cm depth could be accurately identified under a soil moisture of 5%.