BENEdiCTE (Boron Enhanced NEutron CapTurE) Gamma-Ray Detection Module

We present a gamma-ray detection module for Neutron Capture Enhanced Particle Therapy (NCEPT). The system has been optimised for boron-10 neutron capture agents that can be used for dose enhancement in proton and heavy ion therapy. The goal of the module is to distinguish the photopeak at 478 keV from the prompt-gamma emission resulting from the ion-target nuclear interactions. The module consists of a compact 64-channel module, with a large array of SiPM coupled to a 2" diameter and 2" thickness cylindrical LaBr3:Ce scintillator crystal (63 ph/keV conversion efficiency, 16 ns decay time). The electronic front-end ASIC features low-noise processing of photodetector signals, while the pixellated SiPMs detector and individual readout allows for position sensitivity in the crystal. We have characterised the energy resolution of the system experimentally, demonstrating an excellent energy resolution (3.27% at 662 keV), together with the capability of the FPGA-based DAQ integrated in the module to deploy an external synchronization signal to the ion beam bunches, in order to generate anti-coincidence windows. This feature provides a mechanism to distinguish and reject scintillation events from prompt gammas, enhancing the signal-to-background ratio of the spectrometer.