Monte Carlo modelling of a neutron-induced gamma-ray sensor for landmine or explosive detection

摘要

Monte Carlo simulations were carried out to model a thermal neutron-induced gamma-ray sensor for anti-personnel-landmine (APM) or explosive detection. This is done by employing the thermal neutron prompt gamma activation (TNPGA) technique. The neutron capture reaction on nitrogen14N(n,γ)15N is analyzed to detect the subsequent characteristic 10.8?MeV gamma rays. This is done by modelling a suitable geometry consisting of a point252Cf source placed inside a sphere of lead (Pb) which is contained in a cylinder of high density polyethylene (HDPE), together with a NaI (Tl) detector. The sensor geometry was optimized and the optimal configuration was selected to scan a plastic APM buried (2–10) cm. The Monte Carlo results obtained in terms of variations of the signal-to-background ratio, indicated the feasibility of employing14N(n,γ)15N neutron capture reaction for landmine detection and the suitability of the proposed sensor for airport explosives as well.