LLRF Activities in the China ADS Front-End Demo Linac (CAFe) at IMP


2023/09/14 10:00 – 11:30


東海1号館117会議室 + Zoom (※会場変更有 112→117会議室)


Qiu Feng氏 (The Institute of Modern Physics)





方 志高(PHS 4432)


Large particle accelerators, such as CiADS, demand consistently high beam availability, posing a significant challenge for the long-term reliability of the RF system. In the test facility of CiADS (CAFe), the RF transient instabilities caused by the 10 mA beam and the field-emission-induced cavity faults are primary challenges in achieving high-gradient operation for accelerators. We have developed a novel iterative learning control (ILC) scheme to compensate for beam loading. By utilizing prior knowledge of the beam, our algorithm could avoid complex matrix operations and enable the construction of an FPGA-based ILC algorithm. Additionally, we have developed a real-time digital filter with robustness to field emission-induced burst noise, resolving RF instability issues in an innovative way and improving machine reliability and performance.
Improving the accuracy of RF field measurements is a crucial means to enhance the precision of LLRF system control. We have introduced, for the first time, a measurement channel calibration algorithm in continuous wave mode, which eliminates the cross-talk of directional coupler coupling on measurement results. This algorithm has been adopted by the European Spallation Source (ESS), aiding them in achieving precise calibration of beam synchronous phase.