A SiPM-based 144-Channel Detection System for Gamma Spectroscopy up to 20 MeV

We present a 144-independent-channel SiPM-based detection module for gamma spectroscopy with a 3” Ce³⁺ -Sr²⁺ codoped Lanthanum Bromide (LaBr3) scintillator crystal (73 ph/keV conversion efficiency, 25 ns decay time), featuring 84dB dynamic range front-end electronics with automatic gain switching, state-of-the-art energy resolution (2.6% at 662 keV), 80kHz maximum acquisition rate and imaging capabilities. The relatively large number of independent channels is aimed at achieving a large energy range (up to 20MeV) as well as maintaining the best achievable energy resolution without sacrificing the spatial resolution in photon-interaction position reconstruction in order to correct for the relativistic Doppler effect that occurs in accelerator-based nuclear experiments due to the relativistic speed at which the radioactive nuclei move. Experimental measurements are reported to demonstrate the performance of the system in terms of energy resolution, spatial resolution, and dynamic range, confirming the possibility of using Silicon Photomultipliers (SiPMs) - already known for their high robustness, magnetic fields insensitivity, and fast response - as a suitable replacement of Photomultiplier Tubes (PMTs) in nuclear and particle physics experiments.