RF tests of an 805 MHz pillbox cavity at Lab G of Fermilab

Derun Li, J. Corlett, R. MacGill, J. Wallig, M. Zisman, A. Moretti, Z. Qian, V. Wu, R. Rimmer, J. Norem, Y. Torun

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

1 Citation (Scopus)

Abstract

We report recent high power RF tests on an 805 MHz RF pillbox cavity with demountable windows over beam apertures at Lab G of Fermilab, a dedicated facility for testing of MUCOOL (muon cooling) components. The cavity is installed inside a superconducting solenoidal magnet. A 12 MW peak RF power klystron is used for the tests. The cavity has been processed both with and without magnetic field. Without magnetic field, a gradient of 34 MV/m was reached rather quickly with very low sparking rate. In a 2.5 T solenoidal field, a 16 MV/m gradient was achieved, following several weeks of conditioning. Strong multipacting effects associated with high radiation levels were measured during processing with the magnetic field. More recently Be windows with TiN-coated surface have been installed and tested with and without the external magnetic field. 16 MV/m gradient without magnetic field was reached quickly as planned. Less multipacting was observed during the conditioning, indicating that the TiN-coated surface on the windows had indeed helped to reduce the secondary electron emission significantly. A gradient of 16.5 MV/m was finally achieved with magnet on in solenoidal mode and the field up to 4 T. Preliminary inspection of the Be window surface found no visual damage, in comparison with Cu windows where substantial surface damage was found. Preliminary understanding of conditioning the cavity in a strong magnetic field has been developed. More thorough window and cavity surface inspection is under way.
Original languageEnglish
Title of host publicationProceedings of the IEEE Particle Accelerator Conference
Pages1246-1248
Number of pages3
Publication statusPublished - 1 Dec 2003
Externally publishedYes
EventPAC 2003 - Proceedings of the 2003 IEEE Particle Accelerator Conference - Portland, OR, United States
Duration: 12 May 200316 May 2003

Conference

ConferencePAC 2003 - Proceedings of the 2003 IEEE Particle Accelerator Conference
CountryUnited States
CityPortland, OR
Period12/05/0316/05/03

ASJC Scopus subject areas

  • Engineering(all)

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