Studies of a Scalable Electronic Readout Design for a 100 ps Coincidence Time Resolution TOF-PET System

We have developed a scalable detector readout design for a 100 ps coincidence time resolution (CTR) TOF- PET system. The basic PET detector elements are based on 3×3×10 mm3“LGSO” scintillation crystals sidecoupled to arrays of three 3×3 mm2SiPMs. We employed a novel mixed-signal front-end electronic configuration and a low timing jitter FPGA-based TDC for data acquisition. Coincidence data were experimentally acquired for several SiPM bias voltages, comparator thresholds, and timing channels. Before final optimizations, the measured CTR was 103.3 ± 1.5 ps for 3×3×10 mm3 fast LGSO crystals. Furthermore, this readout architecture is scalable to modules and eventually a clinical system with a goal to achieve 100 ps CTR.