Organic scintillator-based alpha/beta detector for radiological decontamination

Morishita, Yuki; Di Fulvio, A.*; Clarke, S. D.*; Kearfott, K. J.*; Pozzi, S. A.*

Nuclear Instruments and Methods in Physics Research A, 935, p.207 - 213, 2019/08

https://doi.org/10.1016/j.nima.2019.04.024

We developed a prototype alpha/beta particle detector using a pulse shape discrimination (PSD) capable organic scintillator, a silicon photomultiplier, and a waveform digitizer. The charge integration PSD technique was used to separate alpha and beta particles. We compared the PSD figure of merit (FOM) values of two scintillators (EJ-299-33 and stilbene), and found that the stilbene (FOM =1.61) performance was superior to the EJ-299-33 (FOM = 0.56) performance, measured using an Am source (5.5 MeV alpha particle emission) and a Sr source. Additionally, the stilbene showed good energy resolution (23.6% FWHM for 5.5 MeV alpha particles). In the pulse height spectrum for the Sr/Y source, the lower energy portion (Sr) and the higher energy portion (Y) could be separated.