Monte Carlo simulation optimisation of zinc sulphide based fast-neutron detector for radiography using a 252Cf source

Neutron radiography is rapidly extending as one of the methods for non-destructive screening of materials. There are various parameters to be studied for optimising imaging screens and image quality for different fast-neutron radiography systems. Herein, a Geant4 Monte Carlo simulation is employed to evaluate the response of a fast-neutron radiography system using a 252Cf neutron source. The neutron radiography system is comprised of a moderator as the neutron-to-proton converter with suspended silver-activated zinc sulphide (ZnS(Ag)) as the phosphor material. The neutron-induced protons deposit energy in the phosphor which consequently emits scintillation light. Further, radiographs are obtained by simulating the overall radiography system including source and sample. Two different standard samples are used to evaluate the quality of the radiographs.