Simulation and Performance Study on Compact Thermal Neutron Collimator Based on Gadoliniumdoped Silicate

In order to achieve the goal of nuclear security, the neutron generator is used to image shielded nuclear material by non-destructive analysis method. In order to improve the imaging quality, it is necessary to collimate the slowed neutrons. In this paper, the Monte Carlo software Geant4 was used to theoretically model a new compact thermal neutron collimator based on gadolinium-doped silicate, and the thermal neutron transmittance and collimation ratio of the collimator were simulated and calculated. The calculation results will be used to guide the subsequent construction of neutron-based nuclear material imaging systems.