Real-Time Signal Processing for Mitigating SiPM Dark Noise Effects in a Scintillating Neutron Detector

Abstract

A 6 LiF:ZnS(Ag) based cold neutron detector with wavelength shifting (WLS) fibers and SiPM photodetector was developed at the NIST Center for Neutron Research. For neutron scattering applications at the NCNR, detector false positives severely diminish the quality of very faint neutron scatter patterns. Thermal noise generated by the SiPM significantly increases the likelihood of false positives by the detector/discriminator. This paper describes and evaluates a digital real-time algorithm implemented on a field programmable gate array (FPGA) which quickly differentiates SiPM thermal noise and noise pulse pile-up from neutron signals. The algorithm reduces deadtime spent on examining noise pulses as well as reduces the number of false positives.

A pulse selection algorithm for SiPM-coupled CLYC detectors

“…The advancement in fast analog-to-digital converters and digital circuits has opened up new opportunities for improving the measurement performance of various radiation detectors. Algorithms such as the pile-up pulse discriminator, baseline recovery, and pulse amplitude discriminator perform better than analog circuits [13][14][15][16]. Langford et al presented a rise time discrimination method for particle identification and background rejection in 3 He proportional counters for neutron detection [17].…”