Monte Carlo simulation and performance evaluation of vehicle radiation portal monitor

In this paper, by using Monte Carlo simulation of MCNPX software, the design and optimization of the dimensions and distances between the plastic scintillation detectors used in the gamma ray portal monitor in order to build based on these optimized dimensions It can be. The test and performance evaluation steps of the gamma ray portal monitor based on the radiation acceptance test section of the International Electrotechnical Commission standard No. IEC 62244:2024 including the false alarm test, the background effects test (on the performance of the detectors), the gamma radiation detection test and the out-of-range response test is accepted. The results of the conducted evaluation tests confirm the compliance of this portal monitor with the IEC 62244 standard. Based on this, it can be concluded that the design, simulation and placement of the detectors have been done with sufficient accuracy and are approved. Also, the minimum detectable activity of the device for the 60Co source was equal to 0.7 microcurie activity and for the 137Cs source equal to 1.5 microcurie activity at 1 meter with a discrimination level of ±2.7σ, which is comparable to the available commercial monitors.