Study on Coincidence Time Resolution with SiPM and TOFPET-ASIC Utilizing LYSO, GAGG and GFAG

The performance of a detection system is defined by the interaction of scintillator, detector and readout electronics. KETEK silicon photomultipliers in combination with PETsys TOFPET-ASICs provide a high-performance detection chain, which will be studied in combination with 3x3x5 mm³ LYSO, GFAG and GAGG crystals. As a detector, a 3x3 mm² timing-optimized KETEK PM3350T silicon photomultiplier with 50 µm cell pitch was used. The TOFPET-ASIC provides 64 channels, each with 25 ps r.m.s intrinsic time resolution and 300 pC dynamic range. First measurements with LYSO yield a CTR of 294 ps FWHM in a temperature stabilized setup environment at 18°C. The studies with GFAG amd GAGG showed, that the time-over-threshold principle is sensitive towards the longer decay time constants and therefore different pulse shapes of GFAG and GAGG. A CTR of 660 ps FWHM for GFAG and 743 ps FWHM for GAGG could be achieved, which has been benchmarked on a dedicated reference setup to be 329 ps for GFAG and 663 ps for GAGG. Both materials could not fully exploit their intrinsic performance. The first results of this setup are very promising, as the performance for LYSO with 294 ps FWHM is close to the reference measurements with 248 ps FWHM. Forthcoming work will utilize a new generation ASIC and temperature stabilized setup environment, which overcomes the current limitations to handle any scintillator at maximum performance.      «

The performance of a detection system is defined by the interaction of scintillator, detector and readout electronics. KETEK silicon photomultipliers in combination with PETsys TOFPET-ASICs provide a high-performance detection chain, which will be studied in combination with 3x3x5 mm³ LYSO, GFAG and GAGG crystals. As a detector, a 3x3 mm² timing-optimized KETEK PM3350T silicon photomultiplier with 50 µm cell pitch was used. The TOFPET-ASIC provides 64 channels, each with 25 ps r.m.s intrinsic ti...     »