Magnetic Studies of AC Loss in Pressurized Rutherford Cables with Coated Strands and Resistive Cores

  • E. W. Collings
  • M. D. Sumption
  • R. M. Scanlan
  • S. W. Kim
  • M. Wake
  • T. Shintomi
Part of the Advances in Cryogenic Engineering Materials book series (ACRE, volume 42)

Abstract

The most recent results in an ongoing study of the influence of interstrand crossover contact resistance, Rc, strand coating, and cable design, on coupling (eddy current) loss in NbTi-strand Rutherford cables for advanced accelerator applications are presented and discussed. Inductive measurements of AC loss in six-layer stacks of Rutherford cable have been made with the applied field both normal to and parallel to the plane of the cable. Cables studied had bare-Cu, Ni-plated, and stabrite-coated strands; the latter were also furnished with metallic or insulating interlayers (cores) of, respectively, unalloyed Ti, stainless steel, and kapton ribbon. The cable packs were cured under pressure (-90 MPa) at temperatures of 150 to 250°C. After pressure release the AC loss was measured under pressures of 0, 36, and 78 MPa. Lowest coupling loss was obtained with bare Cu cable provided the curing temperature was kept below 200°C. The stabrite cable, which exhibited relatively low loss when cured below 170°C and measured under zero pressure, became extremely lossy under 36 MPa and even more so under 78 MPa. Insertion of any of the ribbon interlayers into the stabrite cable tended to eliminate the Rc-based coupling loss, resulting in a cable whose AC loss was small, controllable, and independent of final pressure.

Keywords

Contact Resistance Wide Face Coupling Loss Lawrence Berkeley Laboratory Total Energy Dissipation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    M. Wake, D. Gross, R. Yamada, and D. Blatchley, AC loss in energy doubler magnets, IEEE Trans. Magn. MAG-15, 141–142 (1979).CrossRefGoogle Scholar
  2. 2.
    V.E. Sytnikov, G.G. Svalov, S.G. Akopov, and LB. Peshkov, Coupling losses in superconducting transposed conductors located in changing magnetic fields, Cryogenics 29, 926–930 (1989).CrossRefGoogle Scholar
  3. 3.
    A.P. Verweij, A. den Ouden, B. Sachse, and H.H.J ten Kate, The effect of transverse pressure on the inter-strand coupling loss of Rutherford type of cables, Adv. Cryo. Eng. (Materials) 40, 521–527 (1994).Google Scholar
  4. 4.
    A.J.M. Roovers, A.J. van Pelt, and L.J.M. van de Klundert, AC losses in a prototype NbTi cable for the LHC dipole magnets, Adv. Cryo. Eng. (Materials) 36, 183–190 (1990).CrossRefGoogle Scholar
  5. 5.
    A.P. Verweij, L.E. Eriksson, and H.H.J. ten Kate, Study on the AC magnetization of LHC type of Rutherford cables, in Superconductor 5, ed. by P. Hale (Plenum press, NY 1994) pp. 587–590.Google Scholar
  6. 6.
    Y.Z. Lei, T. Shintomi, A. Terashima, and H. Hirabayashi, AC loss measurements of Rutherford type superconducting cables under mechanical stresses, IEEE Trans. Appl. Superconductivity 3, 747–750 (1993).CrossRefGoogle Scholar
  7. 7.
    A. Kimura, S.W. Kim, N. Kimura, Y. Makida, T. Shintomi, et al, Proceedings Appl. Superconductivity Conf, Boston, MA, October 18, 1994 — to be published.Google Scholar
  8. 8.
    A. Kimura, N. Kimura, Y. Makida, A. Terashima, T. Shintomi, et al, IEEE Trans. Magn. 30, 2515–2518 (1994).CrossRefGoogle Scholar
  9. 9.
    T. Shintomi, A. Kimura, Y.Z. Lei, A. Terashima, and H. Hirabayashi, AC losses of Rutherford-type superconducting cables, Adv. Cryo. Eng. (Materials) 40, 501–508 (1994).Google Scholar
  10. 10.
    M. Polâk, L. Krempasky, I. Hlâsnik, and J. Perot, Losses in 23 strands NbTi and Nb3Sn flat cables, IEEE Trans. Magn. MAG-17, 2035–2038 (1981).CrossRefGoogle Scholar
  11. 11.
    G.T. Mallick, Jr., D. Natelson, W.J. Carr, Jr., G. Snitchler, and V. Kovachev, Results of AC loss measurements on heat treated SSC cables, IEEE Trans. Appl. Superconductivity 3, 744–746 (1993).CrossRefGoogle Scholar
  12. 12.
    A. Kimura, Electromagnetic properties of superconducting compacted stranded conductors, Doctoral Dissertation, The Graduate University for Advanced Studies, 1–1 Oho, Tsukuba-shi, Ibaraki 305, Japan.Google Scholar
  13. 13.
    M.D. Sumption, E.W. Collings, R.M. Scanlan, A. Nijhuis and H.H.J ten Kate, Calorimetric measurements of the effect of Ni and stabrite coatings and resistive interlayers on AC loss in accelerator cables under fixed pressure, companion paper in these Proceedings.Google Scholar
  14. 14.
    V.T. Kovachev, M.J. Neal, D.W. Capone II, et al, Interstrand resistances of SSC magnets, Cryogenics 34, 813–820 (1994).CrossRefGoogle Scholar
  15. 15.
    S. Takâcs, H. Kaneko, and J. Yamamoto, Time constants of normal metals and superconductors at different ramp rates during a cycle, Cryogenics 34, 679 (1994).CrossRefGoogle Scholar
  16. 16.
    E.W. Collings, Applied Superconductivity, Metallurgy and Physics of Titanium Alloys, (Plenum Press, 1986) pp.338–346.CrossRefGoogle Scholar
  17. 17.
    M. Wake, results of as-yet unplublished research.Google Scholar
  18. 18.
    O. Kubaschewski and B.E. Hopkins, Oxidation of Metals and Alloys, (Butterworth and Co., London, 1962) p.38.Google Scholar
  19. 19.
    M.D. Sumption, H.H.J ten Kate, R.M. Scanlan, and E.W. Collings, Contact resistance and cable loss measurements of coated strands and cables wound from them, Proceedings Appl. Superconductivity Conf, Boston, MA, October 18, 1994 — to be published.Google Scholar
  20. 20.
    U.R. Evans, The Corrosion and Oxidation of Metals, First Supplementary Volume, (St. Martin’s Press, New York, 1968).Google Scholar
  21. 21.
    M.D. Sumption and E.W. Collings, results of as-yet unplublished research.Google Scholar

Copyright information

© Springer Science+Business Media New York 1996

Authors and Affiliations

  • E. W. Collings
    • 1
  • M. D. Sumption
    • 1
  • R. M. Scanlan
    • 2
  • S. W. Kim
    • 3
  • M. Wake
    • 3
  • T. Shintomi
    • 3
  1. 1.Department of Materials Science and EngineeringThe Ohio State UniversityColumbusUSA
  2. 2.Lawrence Berkeley LaboratoryBerkeleyUSA
  3. 3.National Laboratory for High Energy Physics (KEK)Ibaraki 305Japan

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