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

摘要

Measurements have been made on photoconductive detectors made from natural Class Ila diamond and from neutron-irradiated GaAs using identical physical geometries. The temporal response, relative proton-to-gamma ratio, and relative sensitivity were measured. For comparison, the same measurements were made on similarly configured InP(Fe) detectors. The temporal response of the diamond detectors varied from 145 to 360 ps full width at half maximum (FWHM) for a 30 ps, 16 MeV end point bremsstrahlung pulse. This compares to 103 ps FWHM for the GaAs detectors. Proton-to-gamma ratios for the diamond detectors were > 3.5 times those of the reference GaAs detector. The ratio was 1.2 times the reference for InP(Fe) detectors. The relative sensitivities of the diamond detectors, compared with the GaAs detectors, was 0.5 to 0.7. The leakage current of the diamond detectors was at least three orders of magnitude lower than the GaAs devices. Finally, the temporal response of nuetron-irradiated diamond detectors was 90 ps FWHM, a significant improvement in speed over natural diamond.