Development of a SiPM-based detection module for large LaBr3:Ce scintillators for nuclear physics applications

In this work we present a SiPM-based photodetector module designed to readout large LaBr3:Ce (1" up to 3") scintillators for nuclear physics experiments. The photodetector is composed by new High-Density cell SiPM technology for Near UltraViolet and blue light detection, named NUV-HD SiPM (Fondazione Bruno Kessler - FBK, Italy). This SiPM shows high Photo Detection Efficiency (PDE > 45% at 380 nm) and low Dark Count Rate (DCR < 100 kcps/mm2). The detector prototype has a modular structure and implements a real-time SiPMs gain stabilization strategy to compensate the gain drift with temperature. The tile is based on an array of 5 × 5 SiPMs, each one having an active area of 6 mm × 6 mm. This array has been here used for 1" scintillator readout and it is foreseen as basic unit for the assembly of larger array to read 2" and 3" scintillator. Preliminary spectroscopic measurements were performed with an array of 5 × 5 NUV-HD SiPMs coupled to a 1" thick LaBr3:Ce. An energy resolution of 3.70 ± 0.05% has been achieved at 662 keV.