Simulation Study on Landmines Detection by Pulsed Fast Thermal Neutron Analysis

• Published in: Arabian journal for science and engineering (2011) 2022, Vol.47 (1), p.879-885
• Main Authors: Xue, Hui, Shi, Guang-Yu, He, De-Dong, Chen, Si-Yuan, Jing, Shi-Wei, Zheng, Yu-Lai
• Format: Article
• Language: English
• Subjects: Engineering; Explosives detection; Fast neutrons; Gamma rays; Humanities and Social Sciences; Inelastic scattering; Land mines; Mine detection; multidisciplinary; Neutron flux; Neutrons; Nuclear capture; Pulse duration; Research Article-Physics; Science; Simulation; Thermal neutrons; Tungsten carbide
• ISSN: 2193-567X; 1319-8025; 2191-4281
• DOI: 10.1007/s13369-021-05742-0

In this paper, MCNP5 code is used to establish a landmine clearance system based on pulse fast thermal neutron method. The system prototype is modeled based on the NG-9 D-T neutron generator, which is independently developed by Northeast Normal University. Gamma rays produced by fast neutron inelastic scattering and thermal neutron capture are used to identify suspicious areas. The neutron flux passing through landmine cell before and after adding neutron reflector into initial detection system is studied. The simulation results show that the addition of a neutron reflection layer hardly improves the flux of fast neutrons passing through the landmine cell during at pulse width of 10 µs; but the thermal neutron flux through the landmine cell in the pulse interval of 90 µs is significantly increased. Among the several common reflector materials, tungsten (W) and tungsten carbide (WC) materials show better reflection performance. When W and WC are used as reflector materials and the thickness is 6 cm, the thermal neutron flux through the landmine cell is 2.00 and 1.90 times the initial value, respectively. The ratio of the thermal neutron flux in the pulse interval to the fast neutron flux during the emission of the neutron pulse increased to 0.468 and 0.444, respectively, from the initial value of 0.259. Finally, the improved model is used to simulate the landmines hidden in different depths. The results show that using 4.44 MeV and 2.22 MeV peak area counts in the region of interest can identify whether there are explosives in the detection area.