THO710
ビーム診断・高周波源 8月7日 7号館71A/71B 17:20-17:40
LIPAc RFカプラにおける電子マルチパクタおよびそれに対する磁気バイアスの効果についてのシミュレーション
Electron simulation about multipactor and effect of magnetic bias in LIPAc RF couplers
○板垣 智信1, Scantamburlo Francesco2, 廣澤 航輝1, 玄 知奉1, 高山 健3, Carin Yann2, Dzitko Herve2（1QST, 2F4E, 3KEK）
○Tomonobu Itagaki1, Francesco Scantamburlo2, Kouki Hirosawa1, Jibong Hyun1, Ken Takayama3, Yann Carin2, Herve Dzitko2（1QST, 2F4E, 3KEK）
During the LIPAc Phase B+ commissioning from 2021 to 2024, visible light emissions were detected from the rubber O-ring RF couplers for the RFQ alongside with damage observed on several O-rings, despite prior enhancement in the cooling capacity of the coupler’s inner conductor. This issue is suspected to be caused by secondary electrons originating from multi-pactoring. A definitive solution involving the implementation of brazed RF couplers had been recommended early on, and high-power testing of these couplers is currently ongoing. Meanwhile, the application of a magnetic field bias to control electron trajectories in the existing O-ring RF couplers has been proposed. Recent electron simulations conducted using CST Studio Suite comprehensively characterized the multipactor behavior in these couplers. The simulation demonstrated that introducing a magnetic field bias can effectively reduce multipactor occurrences over a wide range of RF power. Based on these promising simulation results, preparations are underway for high-power RF tests of an O-ring RF coupler equipped with magnetic bias.