Multipacting in a coaxial coupler with bias voltage for SRF operation with a large beam current. (30th September 2016)

• Record Type: Journal Article
• Authors: Liu, Z.-K.; Wang, Ch.; Chang, F.-Y.; Chang, L.-H.; Chang, M.-H.; Chen, L.-J.; Chung, F.-T.; Lin, M.-C.; Lo, C.-H.; Tsai, C.-L.; Tsai, M.-H.; Yeh, M.-S.; Yu, T.-C.
• Is Part Of: Journal of instrumentation. Volume 11:Number 9(2016:Sep.)
• Page Start: P09015
• Page End: P09015
• Publication Date: 2016-09-30
• Subjects: Accelerator Subsystems and Technologies -- Acceleration cavities and magnets superconducting (high-temperature superconductor; radiation hardened magnets; normal-conducting; permanent magnet devices; wigglers and undulators) -- Instrumentation for particle accelerators and storage rings - high energy (linear accelerators, synchrotrons); Scientific apparatus and instruments -- Periodicals; 502.84
• DOI: 10.1088/1748-0221/11/09/P09015
• Languages: English
• ISSNs: 1748-0221

Abstract

Abstract: A superconducting radio-frequency (SRF) module is commonly used for a high-energy accelerator; its purpose is to provide energy to the particle beam. Because of the low power dissipation and smaller impedance of a higher-order mode for this module, it can provide more power to the particle beam with better stability through decreasing the couple bunch instability. A RF coupler is necessary to transfer the high power from a RF generator to the cavity. A coupler of coaxial type is a common choice. With high-power operation, it might suffer from multipacting, which is a resonance phenomenon due to re-emission of secondary electrons. Applying a bias voltage between inner and outer conductors of the coaxial coupler might increase or decrease the strength of the multipacting effect. We studied the effect of a bias voltage on multipacting using numerical simulation to track the motion of the electrons. The simulation results and an application for SRF operation with a large beam current are presented in this paper.