Gain stabilization and pulse-shape discrimination in a thermally-variant environment for a hand-held radiation monitoring device utilizing Cs2LiYCl6:Ce3+ (CLYC) scintillator

We have utilized CS₂LiYCl₆:Ce³⁺ (CLYC) scintillators in a hand-held instrument for radioisotope identification, known as the Advanced Radiation Monitoring Device (ARMD). The CLYC crystals in ARMD are each read out by a PMT and custom electronics designed to exploit CLYC´s pulse-shape discrimination (PSD) capabilities. ARMD is designed to function in temperatures ranging from -20 to +500°C. CLYC scintillation emission light yield and pulse shapes are a function of temperature, due to the thermal dependence of the responsible scintillation mechanisms. Additionally, PMT gain and electronics readout also exhibit temperature dependence. Gain stabilization and compensation for varying waveform profiles are therefore necessary for robust isotope identification and PSD. We present the results of a complete thermal cycle over the specified range on an ARMD core detector module and describe our method of gain stabilization and PSD compensation to account for thermallydependent waveform profiles.