Study on the System of 14 MeV Neutron Generator-based Explosives Detection Using NaI(Tl) and BGO Detectors

a 14 μs MeV neutron pulse generator-based explosives detection system is introduced, which uses 100 mm×100 mm NaI(Tl) and 50 mm×50 mm BGO as γ detectors. 5 μs-width 14 MeV neutron pulses are produced by the neutron generator with the repetition frequency of 1, 5, 10 or 20 kHz, respectively. A 4 inch NaI(Tl) detector is used to detect the radiative capture γ, and a 2 inch BGO detector is used to detect the inelastic γ from inspected materials. 22 kinds of materials, including 3 kinds of explosives RDX, TNT and NQ are measured. The experimental results show that explosives can be discriminated from common materials correctly with the information of 14N, 1H and 16O concentrations, which are extracted based on the measured γ spectrum.