The temporal response and relative proton-to-gamma ratio of radiation detectors made from natural diamond

The temporal response, relative proton-to-gamma ratio, and relative sensitivity of photoconductive detectors made in identical physical geometries from natural Class IIa diamond and from neutron-irradiated GaAs were measured. The temporal response of the diamond detectors varied from 145 to 360 ps FWHM for a 30 ps, 16 MeV end-point bremsstrahlung pulse. This response compares to 103 ps FWHM for the GaAs detectors. Proton-to-gamma ratios for the diamond detectors were three times those of the GaAs detectors. The relative sensitivities of the diamond detectors, compared with those in the GaAs detectors, were 0.5 to 0.7. The leakage current of the diamond detectors was at least three orders of magnitude lower than those in the GaAs devices. The temporal response of neutron-irradiated diamond detector was 90 ps FWHM, a significant improvement in speed over natural diamond.<>