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Effect of low-temperature baking on the radio-frequency properties of niobium superconducting cavities for particle accelerators

J. Appl. Phys. 96, 1591 (2004); doi:10.1063/1.1767295

Issue Date: 1 August 2004

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Gianluigi Ciovati
Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 and Department of Physics, Old Dominion University, Norfolk, Virginia 23529
Radio-frequency superconducting (SRF) cavities are widely used to accelerate a charged particle beam in particle accelerators. The performance of SRF cavities made of bulk niobium has significantly improved over the last ten years and is approaching the theoretical limit for niobium. Nevertheless, RF tests of niobium cavities are still showing some "anomalous" losses that require a better understanding in order to reliably obtain better performance. These losses are characterized by a marked dependence of the surface resistance on the surface electromagnetic field and can be detected by measuring the quality factor of the resonator as a function of the peak surface field. A low-temperature (100–150  °C) "in situ" bake under ultrahigh vacuum has been successfully applied as final preparation of niobium RF cavities by several laboratories over the last few years. The benefits reported consist mainly of an improvement of the cavity quality factor at low field and a recovery from "anomalous" losses (so-called "Q drop") without field emission at higher field. A series of experiments with a CEBAF single-cell cavity have been carried out at Jefferson Lab to carefully investigate the effect of baking at progressively higher temperatures for a fixed time on all the relevant material parameters. Measurements of the cavity quality factor in the temperature range 1.37–280  K and resonant frequency shift between 6–9.3  K provide information about the surface resistance, energy gap, penetration depth, and mean free path. The experimental data have been analyzed with the complete BCS theory of superconductivity. The hydrogen content of small niobium samples inserted in the cavity during its surface preparation was analyzed with nuclear reaction analysis. The single-cell cavity has been tested at three different temperatures before and after baking to gain some insight on thermal conductivity and Kapitza resistance and the data are compared with different models. This paper describes the results of these experiments and comments on existing models to explain the effect of baking on the performance of niobium RF cavities. ©2004 American Institute of Physics
History: Received 19 March 2004; accepted 7 May 2004
Permalink: http://link.aip.org/link/?JAPIAU/96/1591/1
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KEYWORDS and PACS

Keywords
PACS
  • 74.25.Nf
    Superconductor response to electromagnetic fields (nuclear magnetic resonance, surface impedance, etc.)
  • 74.70.Ad
    Superconducting metals; alloys and binary compounds (including A15, MgB2, etc.)
  • 85.25.Qc
    Superconducting surface acoustic wave devices and other superconducting devices
  • 29.17.+w
    Electrostatic, collective, and linear accelerators
  • 72.15.Lh
    Relaxation times and mean free paths (metals/alloys)
  • 74.20.Fg
    BCS theory of superconductivity and its development
  • 74.25.Fy
    Transport properties of superconductors including electric and thermal conductivity, thermoelectric effects, etc
  • 74.25.Jb
    Electronic structure of superconductors
  • 67.40.Pm
    Transport processes, second and other sounds, and thermal counterflow; Kapitza resistance (liquid 4He)
  • YEAR: 2004

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PUBLICATION DATA

ISSN:
0021-8979 (print)   1089-7550 (online)
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REFERENCES (28)
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  1. S. Calatroni, C. Benvenuti, and V. Ruzinov, 10th Workshop on RF Superconductivity, Tsukuba, Japan, 2001.
  2. Q. Ma and R. A. Rosenberg, 10th Workshop on RF Superconductivity, Tsukuba, Japan, 2001.
  3. B. Bonin and R. W. Roeth, 5th Workshop on RF Superconductivity, Hamburg, Germany, 1991.
  4. W. A. Lanford, Nucl. Instrum. Methods Phys. Res. B 66, 65 (1992).
  5. URL: http://www.jlab.org
  6. J. Halbritter, J. Appl. Phys. 41, 4581 (1971).
  7. G. Ciovati, JLAB-TN-03-003, 2003.
  8. J. Halbritter, FZK 3/70-6, 1970.
  9. P. Kneisel, O. Stoltz, and J. Halbritter, J. Appl. Phys. 45, 2296 (1974).
  10. A. Phillipp and J. Halbritter, IEEE Trans. Magn. 19, 999 (1983).
  11. J. Halbritter, Z. Phys. 266, 209 (1974).
  12. R. Schwab, Externer Bericht 6023, FZK Karlsruhe, 1997.
  13. C. C. Koch, J. O. Scarbrough, and D. M. Kroeger, Phys. Rev. B 9, 888 (1974).
  14. A. Dacca`, G. Gemme, L. Mattera, and R. Parodi, Appl. Surf. Sci. 126, 219 (1998).
  15. C. Z. Antoine, A. Aspart, M. Berthelot, Y. Gasser, J. P. Poupeau, and F. Valin, 9th Workshop on RF Superconductivity, Albuquerque, NM.
  16. K. Kowalski, A. Bernasik, W. Singer, W. Singer, and J. Camra, 11th Workshop on RF Superconductivity, Travemuende, Germany, 2003.
  17. P. Kneisel, 9th Workshop on RF Superconductivity, Albuquerque, NM, 1999.
  18. J. Halbritter, 1st Workshop on RF Superconductivity, Karlsruhe, Germany, 1980.
  19. J. Halbritter, 38th Eloisatron Workshop, Erice, Italy, 1999.
  20. B. Visentin, J. P. Charrier, B. Coadou, and D. Roudier, 9th Workshop on RF Superconductivity, Albuquerque, 1999.
  21. J. Halbritter, 11th Workshop on RF Superconductivity, Travemuende, Germany, 2003.
  22. M. Fouaidy, S. Bousson, T. Junquera, N. Hammoudi, J. C. Le Scornet, and J. Lesrel, 9th Workshop on RF Superconductivity, Albuquerque, NM, 1999.
  23. J. Halbritter, IEEE Trans. Appl. Supercond. 11, 1864 (2001).
  24. K. Saito, 2003 Particle Accelerator Conference, Portland, OR, 2003.
  25. G. Eremeev, M. Liepe, H. Padamsee, and R. Roy, 11th Workshop on RF Superconductivity, Travemuende, Germany, 2003.
  26. M. Ono, E. Kako, T. Shishido, S. Noguchi, and T. Yokoi, 9th Workshop on RF Superconductivity, Albuquerque, 1999.
  27. B. Visentin, 11th Workshop on RF Superconductivity, Travemuende, Germany, 2003.
  28. J. Knobloch, R. L. Geng, M. Liepe, and H. Padamsee, 9th Workshop on RF Superconductivity, Albuquerque, NM, 1999.

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