Readout electronics system for MUSIC detectors in HFRS at HIAF

The High Intensity Heavy-Ion Accelerator Facility (HIAF) is currently under construction in China. As a key component of HIAF, the High Energy Fragment Separator (HFRS) is designed to investigate the properties of rare isotopes far from the beta stability line and their associated nuclear reactions of astrophysical interest. HFRS employs the B$\rho$-TOF-$△$E method, which enables high magnetic rigidity, large ion-optical acceptance, and precise particle identification, making it well-suited for nuclear fragmentation secondary beam experiments. A crucial element in particle identification within HFRS is the energy loss detector ($△$E), which is implemented using the twins Multiple Sampling Ionization Chamber (twins-MUSIC). This design significantly enhances the energy resolution of the gas ionization chamber through multiple sampling. Each twins-MUSIC detector consists of nine channels, including eight anode channels and one cathode channel for correction. The corresponding readout electronics system comprises nine charge-sensitive amplifier (CSA) modules, a readout control module (RCM), and a sub-clock module. The measured data are transmitted to the data acquisition (DAQ) system via a 10 GSPS optical fiber link. The readout electronics system has been fabricated and subjected to comprehensive electrical performance evaluations, including baseline stability, channel linearity, and temperature response tests. Furthermore, joint testing with a radioactive source and the twins-MUSIC detector demonstrated an energy resolution better than 1.04%, confirming the system’s high performance in energy loss measurements.