Simulation and Construction of Fast Neutron Multi-Counter Based on Liquid Flash

Abstract As an important attribute authentication technology, the Fast Neutron Multiplicity Counting analysis method has the potential to solve the shortcomings of existing measurement methods. In this paper, the Geant4 10.4 program based on Monte Carlo method is used to simulate the geometric model, physical process and primary behavior, and simulate the detection system composed of six liquid flash probes in three different layouts to achieve the measurement of sample properties. Pu samples were measured by using different layout detection systems. By comparing the detection efficiency and the multiplicity count rate, it was determined that the No. 2 layout was used as the final detection system, and the detection efficiency was about 3.9%. The variation of the detection efficiency of the simulated sample in the radial direction is obtained. The uniform detection efficiency zone of the system is ±3 cm from the center of the cavity. The detection efficiency deviation is less than 0.12%, the mass deviation is less than 5%, and the deviation variance is less than 10%, and the detection system meets the requirements for sample measurement. Studies have shown that the built detection system has the ability to measure sample properties and can be used in the next step of the study.