A scalable digital pulse process module for the MRPC detector of muon tomography

Muon tomography with cosmic ray muons is a novel technology for high-Z material detection, which requires large-scale, high-efficiency, high spatial resolution detectors to track the muons. From previous studies, we conclude that the multi-gap resistive plate chamber (MRPC) will be an excellent and inexpensive choice for this application, which also offers the possibility of introducing energy information of muons by TOF measurement to image reconstruction of muon tomography owning to the inherent high time resolution of MRPC. To get enough spatial resolution, the dedicated electronics is required to be able to handle thousands of readout channels. To keep the flexibility of charge and time measurement for detector research purpose, a fast preamp with waveform sampling combined with the Digital Pulse Process (DPP) technology was chosen as the readout solution. At present, an 8-ch current sensitive preamp ASIC has been designed and implemented for the SDPP module, and the switched capacitor array (SCA) chip DRS4 designed by the PSI was chosen as the sampler of the SDPP.