Waveform digitization for high resolution timing detectors with silicon photomultipliers

The results of time resolution studies with silicon photomultipliers (SiPMs) read out with high bandwidth constant fraction discrimination electronics were presented earlier [1], [2], [3]. Here we describe the application of fast waveform digitization readout based on the DRS4 chip [4], a switched capacitor array (SCA) produced by the Paul Scherrer Institute, to further our goal of developing high time resolution detectors based on SiPMs. The influence of the SiPM signal shape on the time resolution was investigated. Different algorithms to obtain the best time resolution are described, and test beam results are presented.