Study on time measurement for CSA-based readout electronics in STCF ECAL

Abstract

Super Tau-Charm Facility (STCF) will provide unique support for particle physics research in China owing to its high luminosity and large dynamic range. Its electromagnetic calorimeter (ECAL) is designed as a new type of calorimeter which can perform high-precision energy and time measurement at the same time. Considering the high event rate and pile up induced by high luminosity, and the large channel number scale of ECAL, the readout electronics needs to adopt a high-precision, unconventional, and real-time processing method to reduce the data amount in transmission. Based on the charge-sensitive front-end electronics in energy measurement, an online time measurement method based on waveform fitting algorithm has been studied and implemented in this work. The parameters which would affect the time resolution are analyzed according to simulation and experimental test. After the optimization of electronics, a time resolution of 165 ps at the equivalent deposition energy of 1 GeV is achieved, which indicates that the waveform fitting method based on charge-sensitive readout electronics can meet the future requirements.