• K. Yonehara, M. Chung, A. Jansson, A. Moretti, M. Popovic, A.V. Tollestrup
  Fermilab, Batavia
• M. Alsharo'a, R.P. Johnson, M. Notani
  Muons, Inc, Batavia
• D. Huang
  IIT, Chicago, Illinois
• Z. Insepov
  ANL, Argonne
• T. Oka, H. Wang
  University of Chicago, Chicago, Illinois
• D. Rose
  Voss Scientific, Albuquerque, New Mexico

A high pressurizing hydrogen gas filled RF cavity has a great potential to apply for muon colliders. It generates high electric field gradients in strong magnetic fields with various conditions. As the remaining demonstration, it must work under high radiation conditions. A high intensity muon beam will generate a beam-induced electron swarm via the ionization process in the cavity. A large amount of RF power will be consumed into the swarm. We show the recent non-beam test and discuss the electron swarm dynamics which plays a key role to develop a high pressure RF cavity.