Petiroc2A: Characterization and Experimental Results

Petiroc2A is a 32-channel SiPM readout ASIC, which has been designed for applications requiring precise timing and energy measurement such as time-of-flight positron emission tomography. In this work, experimental results of Petiroc2A are presented.Time and charge measurements for Petiroc2A have been performed at CERN with various SiPM models from FBK, Hamamatsu and Sensl. Scintillators used for the tests are mostly LSO:Ce,Ca crystals with dimensions ranging from 2x2x3mm³ up to 3x3x20mm³. Petiroc2A yields a single-photon time resolution (SPTR) of 90.7 ps FWHM when tested with FBK NUV 1x1mm² SiPM. Meanwhile, the obtained coincidence time resolution (CTR) values when tested with FBK NUV-HD 4x4mm² SiPM and 2x2x3mm³ LSO:Ce,Ca are 85.5 ps FWHM when measured externally and 127.3 ps FWHM when measured using the ASIC internal TDC. Using longer scintillators, 3x3x20mm³ LSO:Ce,Ca, and Hamamatsu S13360-3050PE SiPM with negative output, Petiroc2A yields a CTR value of 222.5 ps FWHM when measured with internal TDC. Using the same configuration outputting positive SiPM signal, Petiroc2A measured a nearly similar CTR, 225.3 ps FWHM. Similar setup yields, an energy resolution of 12.9% for 511 keV photon after correction when measured internally by Petiroc2A.