Influence of SiPM single photon timing resolution on coincidence timing resolution with fast scintillator

Abstract

A coincidence timing resolution (CTR) of scintillation detectors based on SiPMs depends on both photodetector and scintillator properties. The photodetector-related contribution is very important and has a considerable impact on the CTR. The CTR dependence on photon detection efficiency (PDE) is well studied and clarified, but as soon as advances in developments of fast scintillators and fast SiPMs make CTR approaching to a fundamental limit, a role of a single photon timing resolution (SPTR) is increased, and it requires more attention and studies. This study presents results of CTR measurements of LYSO crystals with “old” standard and timing optimized KETEK SiPM samples of 3×3 mm2 size obtained with developed digital signal processing. To complement and extend the studies on LYSO CTR with analysis on how SPTR affects multi-photon timing resolution (MPTR) with different light intensity profiles, experiments with different light sources were carried out and results were compared with an analytical model of SiPM timing resolution.