Pulse shape discrimination of fast neutron and gamma interactions at low energies using Stilbene and EJ-276 coupled to a SiPM (Conference Presentation)

The continued advancements of Silicon Photomultipliers (SiPMs) have made them a viable photosensor for low energy pulse shape discrimination (PSD) between fast neutrons and gammas interactions when coupled to an appropriate scintillator. To assess the performance of two such scintillators, Stilbene and EJ-276, we have conducted studies using 6 mm3 scintillator cells coupled to a SiPM. We demonstrate that both scintillators are viable for conducting PSD for interaction energies from 100 keV to several MeV, whilst optimizing the PSD parameter by varying the integration periods used in its metric. Additionally, we have applied machine learning approaches, in particular boosted decision trees, to characterize the importance of each of the pulse features in a PSD assessment. Identifying the potential of PSD in the low energy region through applying a series of cuts on appropriate pulse parameters.