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Title: Resonant-frequency discharge in a multi-cell radio frequency cavity

Journal Article · · Journal of Applied Physics
DOI:https://doi.org/10.1063/1.4900994· OSTI ID:22402579
; ; ;  [1];  [2]
  1. Department of Physics, Center for Accelerator Sciences, Old Dominion University, Norfolk, Virginia 23529 (United States)
  2. Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States)

We are reporting experimental results on a microwave discharge operating at resonant frequency in a multi-cell radio frequency (RF) accelerator cavity. Although the discharge operated at room temperature, the setup was constructed so that it could be used for plasma generation and processing in fully assembled active superconducting radio-frequency cryo-module. This discharge offers a mechanism for removal of a variety of contaminants, organic or oxide layers, and residual particulates from the interior surface of RF cavities through the interaction of plasma-generated radicals with the cavity walls. We describe resonant RF breakdown conditions and address the issues related to resonant detuning due to sustained multi-cell cavity plasma. We have determined breakdown conditions in the cavity, which was acting as a plasma vessel with distorted cylindrical geometry. We discuss the spectroscopic data taken during plasma removal of contaminants and use them to evaluate plasma parameters, characterize the process, and estimate the volatile contaminant product removal.

OSTI ID:
22402579
Journal Information:
Journal of Applied Physics, Vol. 116, Issue 17; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
Country of Publication:
United States
Language:
English