First investigations of a silicon neutron detector with a carborane converter

We present a new design of a slow neutron detector, based on silicon detectors with innovative materials acting as conversion layers, plus preliminary results that will be the basis for a more complete study in the near future. The sensitive element of this detector is a Schottky barrier silicon diode covered with o-carborane, a novel boron-based converter material that detects neutrons by means of the 10B(n,α)7Li reaction. This sensor has been simulated with the MCNPX Monte-Carlo software in order to find the optimal converter layer thickness that maximizes the neutron detection efficiency. The simulated maximum efficiency is 2.7% for a 20 μm converter layer of the o-carborane fabricated with pure 10B and of 0.5% for the same compound but made with natural boron material. Moreover, the performance of test devices has been investigated by means of an 241AmBe neutron source and the results have been analyzed with the help of GEANT4 simulations. © 2011 IOP Publishing Ltd and SISSA.