Timing Resolution of Monolithic Scintillators Coupled to Laige SiPM Arrays

Timing resolution is one of the most important parameters of scintillation detectors in many applications One of the major fields in which timing resolution with SiPMs is studied are pixelated detectors for medical imaging and TOF PET. However there are many applications in which timing information from large, monolithic crystals is needed. The aim of this work is to study the timing resolution of large SiPM arrays in readout of various, monolithic scintillators. The presented measurements are made with S12642-1616PB-50(X) Hamamatsu TSV MPPC array having a 50×50 μm cell size and effective active area of 48×48 mm (16×16 channels). During the tests, MPPC is treated as a single/large detector. The different active areas of MPPC are achieved by readout of subareas of the device. In the first part of the study, experiments are made with the smallest 10×10×5 mm LSO scintillator and various number of readout channels in order to understand the influence of the detector area (or capacitance). Next, the timing spectra are recorded for 4 types of scintillators: CeBr 3 (1”, 2”), LaBr 3 (1”, 2”), Nal(Tl) (1”, 2”) and BC408 (2”). The optimization steps and the main aspects affecting the timing resolution of large MPPC arrays are discussed.