The construction of China Accelerator Facility for Superheavy Elements(CAFe2) is advancing based on Chinese ADS Front-end Demo Linac(CAFe). However, the original Beam Position Monitor(BPM) read-out electronics of CAFe 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 was developed. This array served as the RF signal conditioning front-end, together with the RF front-end and digital signal processing platform, to constitute a complete BPM read-out electronics. Laboratory testing validated the feasibility of the high-speed RF switch array and the entire read-out electronics. Compared with traditional read-out electronics, the read-out electronics equipped with the high-speed RF switch array enables the measurement of 32 signals from 8 BPM probes. This approach significantly improves the system's integration and reusability, while offers an efficient solution for implementing multi-channel time-division multiplexing measurement under different beam intensities and operating frequencies. Additionally, by simultaneously accessing signals from multiple BPM probes, this system better supports differential measurement. Overall, the high-speed RF switch array not only meets the requirements of CAFe2 but is also applicable for other accelerators with multiple BPM probes.

Beam Position Monitors (BPM) are the non-destructive monitors used most frequently at nearly all linacs, cyclotrons, and synchrotrons. The most basic function of BPM is to provide the accurate position of the centre of mass of the beam for closed orbit feedback and other demands. However, due to the error of actual processing, the k value and the actual electric center will be different with the ideal k value and electric center of BPM, which requires us to accurately measure the k value and offset value of each set of BPM offline. There are 72 sets of BPMs in HIAF BRing & SRing, with 10 specifications and plate radius ranging from 180mm to 330mm, but the shape and size of the front and back pipes connected to bpms are variety during actual installation. Based on theoretical analysis, the k value and offset value of the BPM which electrode plates are too close to the flange are greatly affected by the pipes connected to bpm at both ends, and the measurement error can even reach 9mm. Therefore, this paper takes HIAF BRing and SRing BPM calibration as examples to explain how to accurately calibrate BPM.

The Large Hadron Collider (LHC) is equipped with NiTb superconducting magnets operating at the cryogenic temperature of 2.9 K. A tiny fraction of proton beam at 7 TeV impacting the magnet coils has the potential to generate enough heat, leading to the loss of superconductivity in the magnets. Consequently, it is imperative for machine performance to detect such beam losses before the quench event occurs. To enhance the sensitivity of magnet quench detection through the measurement of beam losses, ongoing efforts focus on the development of cryogenic beam loss monitors. This contribution outlines the design improvements made to a semiconductor-based beam loss detector installed inside the magnet cryostat, positioned just outside the vacuum vessel of the superconductive LHC dispersion suppressor magnets.