Feasibility study for dual higher-order-modes for plasma processing of FRIB superconducting coaxial resonators
Year: 2024
Type: conference-paper
Abstract: In-situ plasma processing is a promising technique to reduce field emission in superconducting radio-frequency cavities and thus maintain maximum accelerator performance for long-term operation. Continuous-wave accelerators such as FRIB are more challenging than pulsed accelerators due to relatively weak coupling (Qext = 2E6 to 1E7 for FRIB) via the fundamental power coupler (FPC). This results in an unfavorable mismatch at room temperature and makes fundamental-mode plasma processing difficult. Hence we have investigated the use of higher-order-modes (HOMs) with less FPC mismatch. Several HOMs are promising for lower-mismatch plasma generation. However, HOMs often present a less favorable plasma distribution. To improve the plasma distribution, we are studying techniques to drive the plasma with two HOMs simultaneously. Plasma development results will be presented for FRIB beta = 0.085 quarter wave resonators, including ignition threshold measurements and plasma distribution assessments.
Source: JACOW
Authors: Tutt,Patrick, Elliott,Kyle, Berrutti,Paolo, Kim,Sang-Hoon, Xu,Ting, Hartung,Walter, Chang,Wei
Language: English
Subfield: Aerospace Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
OpenAlex ID: W6906846287