Fabrication of present-generation microstructured semiconductor neutron detectors

Abstract

Microstructured semiconductor neutron detectors with large aspect-ratio, straight trenches backfilled with neutron sensitive material exhibit superior detection efficiencies over traditional thin-film-coated diodes for solid-state thermal neutron detection. The detectors operate as partial-conformal diffused pin-junction diodes with low leakage current and capacitance. The solid-state silicon substrate detectors operate on a zero to 2.7 V bias and are coupled with signal amplifying and electronic readout components. The intrinsic thermal neutron detection efficiency for a 4-cm2 single-sided MSND reported here is 30.0±0.9% for a neutron beam with normal incidence to the detector surface. The intrinsic thermal neutron detection efficiencies for 0.0253 eV neutrons were determined by calibrating against a calibrated helium-3 gas-filled proportional detector at the Kansas State University TRIGA Mk II nuclear reactor diffraction beam port.