Development of Multi-Channel Beam Signal Conditioning Front-end Based on Time-Division Multiplexing

The construction of the China Accelerator Facility for Superheavy Elements (CAFE2) is advancing based on the Chinese ADS Front-end Demo Linac (CAFe) developed by Institute of Modern Physics. However, the original Beam Position Monitor (BPM) read-out electronics could not meet the requirements of the CAFe2 BPM probes in terms of quantity and the measurement demands of low-intensity heavy ion beams. In response to this challenge, a high-speed RF switch array supporting multi-channel multiplexing, adjustable gain and filtering, and web parameter configuration for different conditions was developed. This array functions as the RF signal conditioning front-end, in combination with the existing RF front-end and digital signal processing platform, constitutes a new BPM read-out electronics system optimized for CAFE2. It enables time-division multiplexed measurement of multiple beam signals across varying beam intensities and operating frequencies. Laboratory test results demonstrate that the high-speed RF switch array supports microsecond-scale switching, provides bandpass filtering with four selectable center frequencies, and offers an adjustable gain range exceeding 60 dB. The superior performance of the switch array-based readout electronics ensures reliable operation and robust support for the BPM system at CAFE2.