Design and evaluation of front-end electronics prototype for the HIAF-HIRIBL gamma array detector

Abstract The Institute of Modern Physics, Chinese Academy of Sciences, is currently constructing the High Intensity Heavy Ion Accelerator Facility (HIAF). HIAF is capable of accelerating heavy ions ranging from protons to uranium, delivering high-energy ion beams with intensities of up to 10 11 ions per second. The High-Rigidity Radioactive Ion Beam Line (HIRIBL) is a key component of HIAF. A high-performance GeV-energy muon beam can be generated using the HIAF-HIRIBL facility. The gamma array detector is a critical component of HIRIBL. The gamma array detector utilizes a thallium-doped cesium iodide (CsI(TI)) crystals coupled with avalanche photodiodes (APDs), capable of detecting gamma rays as well as other types of charged particles. The detector array consists of multiple detection units. A group of 32 detection units is connected to the readout electronics, providing 32 independent readout channels. The readout electronics system comprises a front-end amplification unit (FAU), which integrates 32 charge-sensitive amplifier modules (CSAs), and a readout control unit (RCU). Additionally, a high-voltage power supply is employed to provide the bias voltage to the crystal detector. The charge-sensitive amplifier features adjustable gain, enabling the processing of signals with both high and low amplitudes. The signal enters the readout control unit, where it is processed by the ADC and FPGA, and the resulting data is transmitted to the data acquisition system via a 6 GSPS fiber-optic link. The prototype's readout electronics system has been manufactured and subjected to comprehensive electrical performance testing, including baseline, noise, and channel linearity tests. The readout electronics system was tested in conjunction with a cesium iodide detector. When tested with a 60 Co radioactive source, the results indicated that the system's dual-peak energy resolutions reached 7.39% and 6.52%, respectively.