Pulse shape discrimination for CLYC based handheld instruments

Neutron detectors are used in homeland security to improve the identification of special nuclear materials (SNM). The detection of any neutrons above the natural background is a strong indication of SNM presence. Currently, there is a significant dependence on He-3 tubes for neutron detection. These devices are simple and effective detectors; however they have a number of drawbacks. He-3 tubes are pressure vessels and cannot be brought on board an airplane. They also exhibit micro-phonic effects, which are a serious issue for the handheld instrumentation. The last but not least is a diminishing stockpile of the He-3 gas, which stimulated the recent push to create new neutron detection technologies. In the last few years, RMD has developed a Cs₂LiYCI₆ (CLYC) scintillator that offers (1) efficient thermal neutron detection, which is higher on a per-volume basis than that of He-3; (2) excellent gamma rejection ratio (GRR), better than 1x10^-7; and (3) gamma-ray energy resolution as good as 4% at 662 keV.