Fast neutron dosimetry and spectrometry using silicon carbide semiconductor detectors

Silicon carbide semiconductor neutron detectors have been irradiated with 252Cf fission neutrons, thermal-neutron induced fission neutrons from 235U, and 14-MeV neutrons from a deuterium-tritium neutron generator. In the latter case, reaction peaks corresponding to 12C(n, α)9Be and 28Si(n, α)25Mg reactions have been observed. Multiple reaction branches to the 25Mg ground state and several excited states are observed for the 28Si(n, α)25Mg reaction, and the detector energy calibration for these reactions can be derived from the peak positions. Although only the ground state branch is observed for the 12C(n, α)9Be reaction, the shift of the reaction energy with angle relative to the 14-MeV source can be used to derive an energy scale based on this reaction. These energy response measurements will form the basis for neutron spectrum unfolding methods for inferring incident neutron energy spectra from the resulting recoil-ion energy spectra in silicon carbide detectors. Copyright © 2006 by ASTM International.