Response of a photodiode coupled with boron for neutron detection

We have studied a silicon semiconductor detector as an alternative to commercial ³He-gas-based neutron detectors. In this paper, we present a measurement of the energy spectrum of neutron-induced secondary radiation by using a silicon detector. Polyethylene was used to produce thermal neutrons by using a ²⁵²Cf radioactive source. The photodiode was then irradiated by thermal neutrons, followed by a ¹⁰B converter that produced charged particles. This configuration was found to have a better response to neutrons than a moderator-converter-photodiode configuration. By comparing the measurements with Geant4 simulations, the air gap between the photodiode and the converter was determined to be 0.3 mm and the detector response of the semiconductor device was found to be a smeared Gaussian function with σ = 0.1.