Pulse Shape Discrimination with a CLYC Crystal Read Out by SiPMs for Neutron Background Reduction in Prompt Gamma Range Monitoring

In the field of hadrontherapy, it is demonstrated that the Prompt Gamma (PG) measurements are strongly affected by the presence of a neutron background, which can limit the possibility to perform range monitoring, especially in the framework of Carbon ion therapy. This work is a first step towards the implementation of the Pulse Shape Discrimination (PSD) technique for neutron background reduction in PGI. A statistical analysis has been developed, that is intended to model the performances of a detection system based on the CLYC scintillator in performing Pulse Shape Discrimination, and a Figure Of Merit (FOM) of this detector is evaluated with respect to several parameters. This analysis serves the aim of deducing the optimal parameters to perform PSD, without having to carry out multiple experimental measures, and to assess if the obtained performances are sufficient to effectively perform neutron/gamma discrimination. Considering a setup made of a 1"x1" CLYC scintillator coupled to a NUV-HD SiPM tile the results show a good PSD capability even for low prompt gamma energies. An experimental setup is under development for the validation of the presented statistical analysis which presents a custom ASIC made for hadrontherapy applications.