16-Channel high-resolution time and charge measurement module for the external target experiment in the CSR of HIRFL

High precision time measurement is required in the readout of the neutron wall and TOF walls in the external target experiment of the Cooling Storage Ring (CSR) project in the Heavy Ion Research Facility in Lanzhou (HIRFL). Considering the time walk correction, both time and charge are measured in the readout electronics. In this 16-channel measurement module, time and charge information are digitized by TDCs at the same time based on the Time-Over-Threshold (TOT) method; meanwhile, by employing high-density ASIC chips, the electronics complexity is effectively reduced. Test results indicate that this module achieves a time resolution better than 25 ps and a charge resolution better than 5% over the input amplitude range from 50 mV to 3 V.