RF Breakdown Studies in Tungsten and Copper Structures

Laurent, L; Adolphsen, C; Beebe, S; Pearson, C; Scheitrum, G; Doebert, S; Rodriguez, J A; Wuensch, W; Luhmann, Jr, N C

doi:10.1063/1.2409154

Title: RF Breakdown Studies in Tungsten and Copper Structures

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Abstract

This paper reports on experimental results from the SLAC NLC accelerator structure closeout program, and discusses a study that was conducted to improve the smoothness of machined tungsten for use in high gradient structures. At the Next Linear Collider Test Accelerator (NLCTA), an X-band (11.424 GHz) structure was operated at a lower temperature to determine whether this would decrease the low rate of breakdowns that still occur after initial processing. Also, various vacuum venting experiments were performed to determine the impact of air, airborne particulates, and oxidation on the performance of a processed accelerator structure. As part of a more long-range high-gradient structure development program, alternative materials to copper are being explored. The CLIC study group at CERN has conducted several accelerator experiments at 30 GHz with structures that have tungsten and molybdenum iris inserts. SLAC has also tested versions of the CLIC 30 GHz design scaled to 11.424 GHz. The results have prompted a tungsten material study directed at exploring new fabrication processes that would provide a cleaner and smoother tungsten surface topography suitable for high gradient applications. A significantly improved tungsten surface finish resulted from this material study, and a single cell X-band cavity containing noses with suchmore »« less

Authors:

Laurent, L; Adolphsen, C; Beebe, S; Pearson, C; Scheitrum, G ^[1]; Doebert, S; Rodriguez, J A; Wuensch, W ^[2]; Luhmann, Jr, N C ^[3]

Stanford Linear Accelerator Center, 2575 Sand Hill Rd, Menlo Park, CA 94025 (United States)
CERN, Geneva (Switzerland)
University of California Davis, Dept. of Applied Science, Davis, CA 95616 (United States)

Publication Date:: 2006-11-27

OSTI Identifier:: 20898691

Resource Type:: Journal Article

Journal Name:: AIP Conference Proceedings

Additional Journal Information:: Journal Volume: 877; Journal Issue: 1; Conference: 12. advanced accelerator concepts workshop, Lake Geneva, WI (United States), 10-15 Jul 2006; Other Information: DOI: 10.1063/1.2409154; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0094-243X

Country of Publication:: United States

Language:: English

Subject:: 43 PARTICLE ACCELERATORS; 36 MATERIALS SCIENCE; BREAKDOWN; COPPER; GHZ RANGE 01-100; LINEAR COLLIDERS; MOLYBDENUM; OXIDATION; PARTICULATES; PERFORMANCE; RF SYSTEMS; ROUGHNESS; STANFORD LINEAR ACCELERATOR CENTER; TOPOGRAPHY; TUNGSTEN

Citation Formats


                    Laurent, L, Adolphsen, C, Beebe, S, Pearson, C, Scheitrum, G, Doebert, S, Rodriguez, J A, Wuensch, W, and Luhmann, Jr, N C. RF Breakdown Studies in Tungsten and Copper Structures.  United States: N. p., 2006. 
        Web.  doi:10.1063/1.2409154.

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                    Laurent, L, Adolphsen, C, Beebe, S, Pearson, C, Scheitrum, G, Doebert, S, Rodriguez, J A, Wuensch, W, & Luhmann, Jr, N C. RF Breakdown Studies in Tungsten and Copper Structures.  United States.  https://doi.org/10.1063/1.2409154

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                    Laurent, L, Adolphsen, C, Beebe, S, Pearson, C, Scheitrum, G, Doebert, S, Rodriguez, J A, Wuensch, W, and Luhmann, Jr, N C. 2006.  
        "RF Breakdown Studies in Tungsten and Copper Structures".  United States.  https://doi.org/10.1063/1.2409154.

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@article{osti_20898691,

  title        = {RF Breakdown Studies in Tungsten and Copper Structures},

  author       = {Laurent, L and Adolphsen, C and Beebe, S and Pearson, C and Scheitrum, G and Doebert, S and Rodriguez, J A and Wuensch, W and Luhmann, Jr, N C},

  abstractNote = {This paper reports on experimental results from the SLAC NLC accelerator structure closeout program, and discusses a study that was conducted to improve the smoothness of machined tungsten for use in high gradient structures. At the Next Linear Collider Test Accelerator (NLCTA), an X-band (11.424 GHz) structure was operated at a lower temperature to determine whether this would decrease the low rate of breakdowns that still occur after initial processing. Also, various vacuum venting experiments were performed to determine the impact of air, airborne particulates, and oxidation on the performance of a processed accelerator structure. As part of a more long-range high-gradient structure development program, alternative materials to copper are being explored. The CLIC study group at CERN has conducted several accelerator experiments at 30 GHz with structures that have tungsten and molybdenum iris inserts. SLAC has also tested versions of the CLIC 30 GHz design scaled to 11.424 GHz. The results have prompted a tungsten material study directed at exploring new fabrication processes that would provide a cleaner and smoother tungsten surface topography suitable for high gradient applications. A significantly improved tungsten surface finish resulted from this material study, and a single cell X-band cavity containing noses with such tungsten surfaces will be high power tested soon.},

  doi          = {10.1063/1.2409154},

  url          = {https://www.osti.gov/biblio/20898691},
  journal      = {AIP Conference Proceedings},

  issn         = {0094-243X},

  number       = 1,

  volume       = 877,

  place        = {United States},

  year         = {2006},

  month        = {11}

}

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