Particle Identification in Fast Inorganic Scintillators via Machine Learning*

YAP:Ce is a fast, mechanically robust inorganic scintillator primarily used for X-ray and gamma-ray detection. Differences in scintillation kinetics for gamma rays and alpha particles in YAP:Ce have been reported, but particle identification capability through pulse shape discrimination has not previously been shown. Therefore, YAP:Ce has been paired with additional scintillation material such as ZnS(Ag) in mixed-field applications, but the slow decay time of the latter limits these applications to relatively low count rates. We highlight the limitations of traditional approaches to particle identification in YAP:Ce and showcase the efficacy of an approach based on machine learning. Through a proof-of-concept experiment, we demonstrate that YAP:Ce alone can discriminate between alpha particles and gamma rays in mixed-field radiation environments. We also show that this technique can potentially be extended to other fast inorganics such as YAG:Ce.