SRF2025 - 22nd International Conference on RF Superconductivity

Higher order modes couplers tuning optimization of 1.3 GHz 9 cell SRF cavities for SHINE project

MOP66

22 Sept 2025, 14:30

3h

Ito International Research Center

Board: MOP66

Poster Presentation MC4: SRF Technologies Monday Poster Session

Speaker

xiaoyun pu (Shanghai Advanced Research Institute, Chinese Academy of Sciences)

Description

The Shanghai HIgh repetition rate XFEL aNd Extreme light facility (SHINE) project has entered its construction phase. This state-of-the-art facility includes an 8 GeV electron linear accelerator, which utilizes superconducting radio frequency (SRF) cavities. Each cryomodule within the accelerator comprises eight standard TESLA 1.3 GHz 9-cell superconducting cavities with two Higher Order Modes (HOM) couplers. Effective suppression of HOM is crucial to maintain beam quality and stability. This paper discusses the performance and adjustment experiences related to the HOM couplers integrated within SHINE's 1.3 GHz cryomodules. We present detailed results from vertical and horizontal tests, emphasizing the successful HOM notch filter tuning to maintain the fundamental mode HOM Qext above 3×10¹¹ at 2K. Optimization strategies and revised specifications for HOM tuning have been established and formally approved.