A study of the effect of incremental gamma-ray doses and incremental neutron fluences upon the performance of self-biased 10 B-coated high-purity epitaxial GaAs thermal neutron detectors

High-purity epitaxial GaAs ¹⁰B-coated thermal neutron detectors advantageously operate at room temperature without externally applied voltage. Sample detectors were systematically irradiated at fixed grid locations near the core of a 2 MW research reactor to determine their operational neutron dose threshold. Reactor pool locations were assigned so that fast and thermal neutron fluxes to the devices were similar. Neutron fluences ranged between 10¹¹ n/cm² to 10¹⁶ n/cm². GaAs detectors were exposed to exponential fluences of base ten. Twelve detector designs were irradiated and studied, differentiated between p-i-n diodes and Schottky barrier diodes. The irradiated ¹⁰B-coated detectors were tested for neutron detection sensitivity in a thermalized neutron beam