Nuclear Science and Techniques

《核技术》(英文版) ISSN 1001-8042 CN 31-1559/TL     2019 Impact factor 1.556

Nuclear Science and Techniques ›› 2018, Vol. 29 ›› Issue (6): 83 doi: 10.1007/s41365-018-0418-9


Study of the crosstalk evaluation for cavity BPM

Jian Chen 1,2 • Yong-Bin Leng 1 • Lu-Yang Yu 1 • Long-Wei Lai 1 • Ren-Xian Yuan 1   

  1. 1 Shanghai Institute of Applied Physics, Chinese Academy of Science, Shanghai 201204, China
    2 University of the Chinese Academy of Science, Beijing 100049, China
  • Contact: Yong-Bin Leng
  • Supported by:

    This work was partially supported by the National Natural Science Foundation of China (Nos. 11575282 and 11305253).

Jian Chen, Yong-Bin Leng, Lu-Yang Yu, Long-Wei Lai, Ren-Xian Yuan. Study of the crosstalk evaluation for cavity BPM.Nuclear Science and Techniques, 2018, 29(6): 83     doi: 10.1007/s41365-018-0418-9


In order to pursue high-precision beam position measurements for free-electron laser facilities, a cavity beam position monitor (CBPM) is employed to measure the transverse position that can meet the requirement of position resolution at a sub-micrometer or even nanometer scale. However, for the pill-box cavity BPM, crosstalk between the cavities will have an effect on the accurate measurement of beam position. To reduce the effect of crosstalk on CBPM performance and ease the measurement of the isolation between the cavities, the cavities with a slight difference in resonant frequency were designed and applied in the Dalian coherent light source and Shanghai soft X-ray free-electron laser facilities. Furthermore, two methods, the principal component analysis method and the method of harmonic analysis, are proposed in this paper to evaluate the crosstalk. The results demonstrate that the two methods are feasible in evaluating the crosstalk between the cavities.

Key words: Crosstalk, Pill-box cavity BPM, PCA, Harmonic analysis, Resolution