Fast electronics for particle Time-Of-Flight measurement, with focus on the SAMPIC ASIC

International audienceMeasuring the Time Of Flight (TOF) of particles with picosecond (ps) precision opens new fields for particle physics and medical instrumentation. It indeed permits the localization of particle production with a few mm precision which is of direct use for PET scanners, but also permits associating particles coming from a common primary interaction in the case of high background in physics experiments. The progress in ultra-fast digitizing electronics (including high-end oscilloscopes) demonstrated that ps timing accuracy can be reached simply by directly sampling the detector signal at high rates and extracting time information by interpolation of the samples located in and around the leading edge of the signal. But when one has to deal with high integration levels, large number of channels, or high counting rates, a compact solution is mandatory and the new concept of Waveform Time to Digital Converter (WTDC) permits facing all these constraints in a very compact and powerful way. This paper will summarize the requirements for high-precision time measurements, explain the concept of WTDC, then focus on the SAMPIC ASIC and its associated boards and modules. The main characteristics will be described as well as the performances obtained on test benches and when coupling the modules to fast detectors