Gamma Scintillator System Enhancement for Neutron Detection using Boron Carbide for Homeland Security

An efficient and low cost 10B based thermal neutron detector as a replacement for 3He based neutron detectors is suggested. The detection is based on an enhancement to a scintillator gamma-rays detector. 3He supply for neutron detectors is gradually become harder to obtain(1) since the commercial production of this isotope has been practically ended. The 10B(n, )7Li interaction is characterized with two energetic ion and a 478 keV gamma photon which is emitted from the excited 7Li in 94% of the interactions(2). A tailored Monte-Carlo code for the detector model was written in MATLAB in order to assess the detector's efficiency. The simulation model is based on ENDF/B-VII.0(3) libraries for neutrons cross sections, and XCOM(4) database for gamma absorption coefficients. By varying the B4C thickness, optimal efficiency was obtained both for natural occurring 10B compound with atomic abundance of 19.8% as well as for boron-10 enriched to 96%