Microstructured semiconductor neutron detector (MSND)-based Helium-3 Replacement technology

The present work employs MSND technology as a ³He gas-tube direct-replacement technology. The MSND-based Helium Replacement (HeRep) is a single instrument utilizing thirty 4-cm² active area MSNDs to directly replace ³He-based proportional neutron counters. The HeRep Mk II prototype yielded 102.71±0.84% of the neutron detection efficiency of a 4-atm Reuter Stokes ³He gas-filled detector with the same active dimensions and test setup from a ²⁵²Cf source. The HeRep Mk II matched the efficiency of the ³He detector while using MSNDs that each had 20% intrinsic-efficiency for thermal-neutrons.