Improvement on pulse-shape discrimination performance of SiPM array coupled Cs₂LiYCl₆:Ce³⁺ detector

Pulse-shape discrimination (PSD) is essential to separate neutrons from other particles in space, given the complex radiation environment. As the SiPM array coupled Cs₂LiYCl₆:Ce³⁺ (CLYC) detector delivers slow charge signals resulting from the large parasitic capacitance of SiPMs, the PSD performance conducted by the traditional charge-comparison method can be significantly sub-optimal. In this study, a method combining a digital shaping algorithm and traditional charge-comparison method is developed to improve the PSD performance of the detector. The current pulse of CLYC is extracted from the slow charge output by the shaping algorithm, and the optimized PSD figure-of-merit (FoM) value improves 13.70% by using this method. Moreover, the piled-up events at high count rate will be lessened because the shaping algorithm reduces the pulse width. Also, this method can be applied to other detectors with charge outputs.