Development of compact high efficiency microstructured semiconductor neutron detectors

Semiconductor diode detectors coated with neutron reactive materials are generally fashioned as planar diodes coated with ¹⁰B, ⁶LiF, or Gd. Planar detectors coated with ¹⁰B or ⁶LiF are limited to less than 5% intrinsic thermal neutron detection efficiency. Detectors coated with Gd can achieve higher efficiencies, but the low-energy signatures are problematic in the presence of background radiations. Microstructured semiconductor neutron detectors (MSNDs) can now achieve a tenfold increase in neutron detection efficiency over the planar diode designs. These semiconductor neutron detectors are fashioned with a matrix of microstructured patterns etched deeply into the semiconductor substrate and, subsequently, backfilled with neutron reactive materials. Intrinsic thermal-neutron detection efficiencies exceeding 35% have been achieved with devices no thicker than 1 mm while operating on less than 5 V, now allowing for instrumentation to be realized with similar performance as ³He gas-filled detectors. - Highlights: • Microstructured semiconductor neutron detectors have over 35% detection efficiency. • The MSNDs are available in compact packages at low cost. • The MSND packages can be arranged into multi-element arrays. • Neutron measurements from three instruments built with MSND arrays are presented.