HOM coupler design for 166.6 MHz SC cavity

  • Xuerui HaoEmail author
  • Zhongquan Li
  • Pei Zhang
  • Fanbo Meng
Original Paper



Higher-order modes (HOMs) may affect beam stability and refrigeration requirements of superconducting cavity such as the 166.6 MHz SC cavity, which is studied at IHEP. Under certain conditions, beam-induced HOMs can accumulate sufficient energy to destabilize the beam or quench the superconducting cavities.


In order to limit these effects, we consider the use of the HOM coupler with HOMs extraction on the cutoff tubes of the 166.6 MHz SC cavity.


The HOM coupler can deeply suppress the fundamental mode and efficiently extract dangerous high-order modes.


In this paper, the HOM coupler design process is presented, which operates at 166.6 MHz. The RF and thermal behavior are discussed. In order to verify the designs, a rapid prototype for the favored coupler was fabricated and characterized on a low-power test stand.


HOMs \(Q_{\mathrm{ext}}\) \(Q_{\mathrm{load}}\) S21 R/Q 



I would like to thank Dr. Zhang Xinying and Dr. Zheng Hongjuan from RF Group of Accelerator Division in IHEP for discussing design options and thank Dr. Luo Yuanli from RF Group of Accelerator Division in IHEP for his help in the test. This work has been supported by the HEPSTF project funding.


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Copyright information

© Institute of High Energy Physics, Chinese Academy of Sciences; Nuclear Electronics and Nuclear Detection Society 2019

Authors and Affiliations

  1. 1.Institute of High Energy PhysicsBeijingPeople’s Republic of China
  2. 2.University of Chinese Academy of SciencesBeijingPeople’s Republic of China

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