Applied Physics Letters
Feedback | Help | Exit
Applied Physics Letters
Search:
   
 
 
 
Previous Article
L10 FePt films deposited on pyramid-type Si substrate for perpendicular magnetic recording media
Tetragonal L10 FePt films are deposited on the pyramid-type Si substrates fabricated by chemical etching process from (100) Si wafers. The films are composed of different easy-axis orientation FePt gr...
Next Article
Room temperature ferromagnetism in two-step-prepared Co-doped ZnO bulks
We have prepared Co-doped ZnO bulks with a two-step method. The bulk samples are sintered at the temperature above 1000  °C to get pure single phase and then treated by Zn vapor in a vac...

Improved oxygen diffusion model to explain the effect of low-temperature baking on high field losses in niobium superconducting cavities

Appl. Phys. Lett. 89, 022507 (2006); doi:10.1063/1.2220059

Published 13 July 2006

You are not logged in to this journal. Log in

Gianluigi Ciovati
Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 and Department of Physics, Old Dominion University, Norfolk, Virginia 23529
Radio-frequency (rf) superconducting cavities made of high purity niobium are widely used to accelerate charged particle beams in particle accelerators. The major limitation to achieve rf field values approaching the theoretical limit for niobium is represented by "anomalous" losses which degrade the quality factor of the cavities starting at peak surface magnetic fields of about 100  mT, in the absence of field emission. These high field losses are often referred to as Q drop. It has been observed that the Q drop is drastically reduced by baking the cavities at 120  °C for about 48  h under ultrahigh vacuum. An improved oxygen diffusion model for the niobium-oxide system is proposed to explain the benefit of the low-temperature baking on the Q drop in niobium superconducting rf cavities. The model shows that baking at 120  °C for 48  h allows oxygen to diffuse away from the surface, and therefore increasing the lower critical field towards the value for pure niobium. ©2006 American Institute of Physics
History: Received 18 August 2005; accepted 1 June 2006; published 13 July 2006
Permalink: http://link.aip.org/link/?APPLAB/89/022507/1
BUY THIS ARTICLE   (US$24)
Download HTML Download Sectioned HTML Download PDF (67 kB) View Cart

KEYWORDS and PACS

Keywords
PACS
  • 74.70.Ad
    Superconducting metals; alloys and binary compounds (including A15, MgB2, etc.)
  • 74.25.Fy
    Transport properties of superconductors including electric and thermal conductivity, thermoelectric effects, etc
  • 74.25.Ha
    Magnetic properties of superconductors
  • 74.25.Op
    Mixed states, critical fields, and surface sheaths in superconductors
  • YEAR: 2006

RELATED DATABASES


To view database links for this article,
you need to log in.
To view database links for this article,
you need to log in.

PUBLICATION DATA

ISSN:
0003-6951 (print)   1077-3118 (online)
Publisher:
AIP is a member of CrossRef AIP

REFERENCES (19)
View in Separate Window/Tab
For access to fully linked references, you need to log in. For access to fully linked references, you need to Log in.
  1. B. Visentin, J. P. Charrier, B. Coadou, and D. Roudier, in Proceedings of the 9th Workshop on RF Superconductivity, Santa Fe, NM, 1999 edited by F. Krawczyk, (Los Alamos National Laboratory,Santa Fe, NM, 2000), p. 198.
  2. P. Kneisel, in Proceedings of the 9th Workshop on RF Superconductivity, Santa Fe, NM, 1999, edited by F. Krawczyk, (Los Alamos National Laboratory, Santa Fe, NM, 2000), p. 328.
  3. A. Dacca, G. Gemma, L. Mattera, and R. Parodi, Appl. Surf. Sci. 126, 219 (1998).
  4. B. R. King, H. C. Patel, D. A. Gulino, and D. J. Tatarchuk, Thin Solid Films 192, 351 (1990).
  5. Q. Ma, P. Ryan, J. W. Freeland, and R. A. Rosenberg, J. Appl. Phys. 96, 7675 (2004).
  6. G. Ciovati, J. Appl. Phys. 96, 1591 (2004).
  7. C. Y. Ang, Acta Metall. 1, 123 (1953).
  8. D. Richter and T. Springer, Phys. Rev. B 18, 126 (1978).
  9. C. Benvenuti, S. Calatroni, and V. Ruzinov, in Proceedings of the 10th Workshop on RF Superconductivity, Tsukuba, Japan, 2001, edited by S. Noguchi et al. (KEK, Tsukuba, Japan, 2001), p. 441.
  10. H. Safa, in Proceedings of the 10th Workshop on RF Superconductivity, Tsukuba, Japan, 2001, edited by S. Noguchi et al. (KEK, Tsukuba, Japan, 2003), p. 279.
  11. Q. Ma, (private communication).
  12. Q. Ma, and R. A. Rosenberg, in Proceedings of the 10th Workshop on RF Superconductivity, Tsukuba, Japan, 2001 edited by S. Noguchi et al. (KEK,Tsukuba, Japan, 2003), p. 368.
  13. B. R. King and B. J. Tatarchuk, Thin Solid Films 192, 371 (1990).
  14. I. Arfaoui, C. Guillot, J. Cousty, and C. Antoine, J. Appl. Phys. 91, 9319 (2002).
  15. G. P. Van der Mey, P. H. Kes, and D. De Klerk, Physica B 95, 369 (1978).
  16. C. C. Koch, J. O. Scarbrough, and D. M. Kroeger, Phys. Rev. B 9, 888 (1974).
  17. H. Padamsee, G. Eremeev, I. Bazarov, J. Kaufman, J. Shipman, and M. Liepe, in Proceedings of the Pushing the Limits of RF Superconductivity Workshop, Argonne, IL, 2004, edited by K. J. Kim and C. Eyberger (ANL, Argonne, IL, 2005), p. 291.
  18. K. Saito, in Proceedings of the 2003 Particle Accelerator Conference, Portland, OR, 2003, edited by J. Chew, P. Lucas, and S. Webber (IEEE Catalog Number: 03CH37423C), p. 462.
  19. R. D. Blois and W. de Sorbo, Phys. Rev. Lett. 12, 499 (1964).

CITING ARTICLES
For access to citing articles, you need to log in.
For access to citing articles, you need to Log in.


Copyright © American Institute of Physics