Strain Studies on Superconducting Nb3Sn Tape Using Differential Thermal Contraction and Other Methods

  • C. King
  • M. Benz
  • D. Grey
  • A. Mantone
  • M. Murray
Part of the Advances in Cryogenic Engineering Materials book series (ACRE, volume 42)

Abstract

Nb3Sn tape, manufactured by the General Electric Company for cryocooled, magnetic resonance imaging (MRI) magnets, was examined to determine the influence of strain on critical current, Ic, over a wide range of magnetic fields and temperatures. Copper stabilized Nb3Sn tapes were strained by differential thermal contraction by waxing or epoxying the samples to 4.7 cm diameter short sample test bobbins made of brass, stainless steel, Inconel, nickel, niobium and molybdenum. These samples were measured for Ic in transverse fields ranging from 0 to 7 Tesla (T) and over a temperature range of 4 2 to 16 Kelvin (K). Additionally, Nb3Sn tape, subjected to bend, twist and pressure stresses, was measured for Ic degradation to determine handling limits during manufacture and insulation of the tape, as well as magnet winding. Finally, unstabilized, reacted Nb3Sn foil subjected to various tensile loads was tested for Ic degradation. Surface metallography was used to relate cracking of the Nb3Sn layer to Ic degradation.

Keywords

Axial Strain Body Magnetic Resonance Imaging Cryogenic Engineer Nb3Sn Layer Differential Thermal Contraction 
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.N. Wilson, “Superconducting Magnets”, Clarendon Press, Oxford (1983) pgs. 294–297.Google Scholar
  2. 2.
    M. Murray et al., Effect of compressive and tensile strains on the critical current density of liquid-phase diffusion processed Nb3Sn, “Processing Long Lengths of Superconductors”, U. Balachandran, E.W. Collings and A. Goyal eds., TMS (1994)Google Scholar
  3. 3.
    U.S. Patent # 5,299,758, Superconducting Tape from Laminated FoilsGoogle Scholar
  4. 4.
    J.W. Ekin, IEEE Transactions on Magnetics, MAG-15:197 (1979)CrossRefGoogle Scholar
  5. 5.
    M. Esterman, Characterization of the critical current in Nb3Sn superconducting tape under different mechanical loading conditions, GEMS Design Record File, 1993Google Scholar
  6. 6.
    C. King. Nb3Sn tape drift vesus defect and handling limits, GEMS Design Record File. 1994Google Scholar
  7. 7.
    U.S. Patent # 5,140,266. Apparatus and method for the non-destructive evaluation of a bifilar superconducting windingGoogle Scholar
  8. 8.
    U.S. Patent # 5,109,593, Method of melt forming a superconducting joint between superconducting tapesGoogle Scholar
  9. 9.
    H. Kanithi et al., Fabrication and characterization of fine filaments of NbTi in a copper matrix, “Advances in Cryogenic Engineering (Materials)”, R.P. Reed and A.F. Clark, eds Vol. 32. 731–738 (1986)Google Scholar
  10. 10.
    B.X. Xu et al., A cryogen-free superconducting magnet with 95 cm warm bore for whole body MRI, MT-14, 1995Google Scholar
  11. 11.
    B.X. Xu et al., An open refrigerator cooled superconducting magnet for the special purpose of magnetic resonance imaging, MT-14, 1995Google Scholar
  12. 12.
    J.F. Schenk, et al., Superconducting open-configuration MR imaging system for image guided therapy, Radiology 1995; 195:805–814Google Scholar
  13. 13.
    J.W. Ekin, Strain scaling law for flux pinning in practical superconductors. Part 1 : basic relationship and application to Nb3Sn conductors. Cryogenics 20:611 (1980)CrossRefGoogle Scholar
  14. 14.
    J.W. Ekin, Transverse stress effect on multifilamentary Nb3Sn superconductors. “Advances in Cryogenic Engineering (Materials)”, R.P. Reed and A.F. Clark, eds., Vol. 34, 547–552 (1988)Google Scholar

Copyright information

© Springer Science+Business Media New York 1996

Authors and Affiliations

  • C. King
    • 1
  • M. Benz
    • 2
  • D. Grey
    • 1
  • A. Mantone
    • 1
  • M. Murray
    • 2
  1. 1.GE Medical SystemsFlorenceUSA
  2. 2.GE Corporate Research and Development CenterSchenectadyUSA

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