High event rate, pulse shape discrimination algorithm for CLYC

CLYC is a scintillation material that is a viable alternative to ³He for neutron detection because the shape of the scintillation emission depends on the linear energy transfer producing the event, e.g., electrons from gamma-rays versus charged ions from neutrons. Analyzing the pulse shape on an event-by-event basis discriminates the neutron events from the gamma-ray event, which is called pulse shape discrimination. The long decay time associated with the scintillation emission of CLYC can result in pulse pile-up for event rates exceeding 100 kHz. One method to address this issue is to develop digital signal processing algorithms to remove pile up, while providing gamma-neutron discrimination and gamma spectra. Research on the algorithm development using saved CLYC pulses processed offline on a personal computer with C++ code indicate that CLYC can provide pulse shape discrimination exceeding 600,000 events per second, primarily from gamma events. The algorithm digitally suppressed the decay tail, allowing for unique temporal identification of a pulse (pile-up removal). Additional filtering of the pulse is done to reduce noise, and peak-to-tail information is obtained on filtered data within a time frame less than 1 μs to provide the pulse shape discrimination.