Picosecond timing performances of the FERS time unit

Abstract Next-generation high-energy physics experiments will employ high-granularity detectors with thousands of readout channels, necessitating the use of low-power, compact ASICs. The CAEN FrontEnd Readout System (FERS) 5200 integrates these ASICs within small, synchronizable, and distributable systems featuring both Front and Back Ends. The A5203 FERS module incorporates the recently released CERN picoTDC ASIC, enabling high-resolution timing measurements for Time of Arrival (ToA) and Time over Threshold (ToT). In this work, we analyze the performance of the A5203 unit, which has a 3.125 ps least significant bit (LSB), delivering ToA measurements with an RMS resolution of approximately 7 ps for signals of fixed amplitude, and approximately 20 ps RMS for input signals with variable amplitude over a 50 dB dynamic range over a single board. The amplitude-dependent walk effect is corrected using ToT, which, in addition to walk correction, is also utilised for signal amplitude reconstruction and background reduction. The A5203 has been successfully applied across various experimental and industrial contexts. In the concluding section of this paper, we will discuss its application within the ProVision project: a PET scanner specialised in imaging aggressive prostate cancer at an early-stage.