Optimum design of detector structure for road transport inspection

A Nuclear Material Detection System (hereafter “NMDS”) is needed to search and detect neutron and/or gamma-ray emitting nuclides such as a dirty bomb during their road transport. However, since it is expected that this material is shielded with high-density material, high detection ability of the detection system is required. In this paper, in order to enhance detection ability of the detection system, we have employed a 3He detector, a NaI detector, and four GM tubes with four different energy cut-off filters. Using Monte Carlo simulation, optimal arrangement of detectors has been determined.