The role of stopping layer and conversion structure on fast neutron imaging.

Fast neutron imaging offers unique advantages in the non-destructive detection of large volume samples. We have proposed a novel method to enhance the spatial resolution and detector efficiency of fast neutron imaging detectors by adding a stopping layer and conversion array. In the Geant4 simulation, incorporating a 300 μm thick boron carbide stopping layer behind the conversion layer can enhance the spatial resolution by 40.4 %. The cube array structure leads to a 28.7 % increase in the conversion efficiency for recoil protons as compared with the flat polyethylene layer. The simulation results illustrate that a spatial resolution of the microchannel plate fast neutron detector of 123 μm can be achieved with a detection efficiency of 0.2 % for fast neutrons. Indeed, this work holds significant reference for the design and optimization of fast neutron imaging detectors. [ABSTRACT FROM AUTHOR]