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


2023/09/14 10:00 – 11:30


Tokai 1st Bulid. Room-117 + Zoom (*Venue changed from 112 to 117)


Qiu Feng (The Institute of Modern Physics)





FANG Zhigao (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.

Release date 2023/09/05 Updated 2024/03/02