Geant4 and MCNP6.2 modeling of fast-neutron detectors based on single-crystal chemical vapor deposition diamond

Diamond photoconductive detectors have been shown to detect fast neutrons with high gamma insensitivity. Depending on the application and the incident neutron energy, there are many possible choices when considering how diamond elements may be sized, arranged, and instrumented. As part of our design effort, we are using Geant4 and MCNP6.2 to simulate the effects of fast neutrons impinging on diamond detectors ranging in thickness from a few microns to a few hundred microns that are 4 mm on a side with intervening materials and other physical parameters. The models may be used to compare diamond detector measurements with incident neutrons ranging from ~1 to 14.1 MeV to better understand the nuclear and atomic physics effects contributing to an electronic signal. We are investigating pulse height, signal-to-noise ratio, and timing characteristics of prototype single-crystal chemical vapor deposition diamond detectors.