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.