Nuclear Techniques ›› 2018, Vol. 41 ›› Issue (11): 110203-110203.doi: 10.11889/j.0253-3219.2018.hjs.41.110203

• LOW ENERGY ACCELERATOR, RAY AND APPLICATIONS • Previous Articles     Next Articles

Study on FIR filter of the accelerator bunch-by-bunch digital feedback system

LYU Penghui1, YIN Di1, YUE Junhui1, CAO Jianshe1, WEI Shujun1, LAN Qinghong1,2, DU Yaoyao1, LIU Fang1, LU Yanhua1   

  1. 1 Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China;
    2 University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2017-11-21 Revised:2018-05-19 Online:2018-11-10 Published:2018-11-20

Abstract: [Background] When the beam goes through the high-frequency cavity and the vacuum chamber of the accelerator, the coupled-bunch instability caused by the high-order mode and the resistive wall will limit the threshold of the beam.[Purpose] This study aims to control the coupled-bunch instability by design of a longitudinal or transverse feedback system.[Methods] The accelerator digital feedback system was designed to filter the beam signal and make a 90° phase shift by using the finite impulse response (FIR) filter to finally obtain the feedback signal. The FIR filter can be designed by using the least square fitting method and the selective FIR filter method. The difference between the two methods was studied in the transverse and the longitudinal feedback system. After optimized the selective filter method, the operational reliability and filtering effect of the FIR filter designed by using the selective filter method are analyzed deeply.[Results] The results show that the selective filter method is more simple and better.[Conclusions] Proposed method can be referenced for designing FIR filter of the feedback system.

Key words: Transverse feedback, Longitudinal feedback, Finite impulse response filter, The least square fitting method, Selective FIR filter method

CLC Number: 

  • TL506