Thermal Neutron Discrimination Using a Novel Phoswich Detector of Gd3Ga3Al2O12:Ce,B and CsI:Tl Single Crystals

Abstract

A phoswich detector was fabricated using a combination of single-crystal scintillators of CsI:Tl and Gd3Ga3Al2O12:Ce,B. The performance characteristics of this novel phoswich detector were investigated for thermal neutron detection in the presence of different gamma backgrounds using an Am–Be source and in a research reactor beam line. High atomic density and excellent thermal neutron capture cross section of Gd leads to the high detection efficiency for thermal neutrons in a 1-mm thin disk of Gd3Ga3Al2O12 crystal. The high figure of merit of ~6.5 obtained for thermal neutron detection ensures the detector’s excellent discrimination property in the presence of high gamma background.