The china spallation neutron source (CSNS) is a high-current proton accelerator, which relies on its beam loss monitor (BLM) system for critical roles in equipment machine protection and residual activation dose control; in CSNS Phase I, the BLM system adopted NI’s PXIe-6358 acquisition card combined with self-developed front-end analog electronics, while the rapid cycling synchrotron (RCS) of CSNS-II requires an upgraded and fully localized BLM system to meet enhanced operational demands.

This study aims to develop a novel ZYNQ-based BLM electronics system to replace the existing NI data acquisition system in CSNS-II RCS, realizing comprehensive functions including beam loss signal acquisition, gain control, Machine Protection Signal (MPS) output, and EPICS PV publishing.

The system comprises custom-developed components: a 19-inch 3U chassis with a dedicated backplane bus, 3 kV low-ripple high-voltage power modules, front-end analog boards, and digital acquisition boards based on the ZYNQ7020 system-on-chip (SOC) integrated with AD7060 and LTC2668, along with developed Linux drivers (including an AXI-DMA-based ADC driver and an AXI-GPIO-based gain control driver) and EPICS IOC software; it was subjected to laboratory functional tests using 25 Hz, 50 μs–1 ms pulse signals to simulate ion chamber outputs and on-beam tests at the RCS local station.

Laboratory tests validated key functions such as external trigger waveform acquisition, gain control, MPS threshold output, and background subtraction, while on-beam tests at the RCS local station clearly captured beam loss signals and extraction interference signals, with the system achieving 100% localization and meeting all engineering specifications.

In conclusion, the ZYNQ-based BLM system has completed the development of core components and demonstrated full functionality, enabling it to effectively replace the existing NI acquisition system and making it well-suited for beam loss measurement in CSNS-II.