Electrical Resistivity of a High-Tc Superconductor for Electric Current Higher Than Ic

  • M. Shiotsu
  • K. Hata
  • A. Sakurai
  • C. Suzawa
  • S. Isojima
  • K. Sato
  • T. Fukui
Part of the Advances in Cryogenic Engineering book series (ACRE, volume 44)

Abstract

The electrical resistivity of a high-Tc superconductor for I > I c is not clarified until now as a function of electric current through the conductor, I, and temperature of the conductor, T, because T varies with I due to joule heating. An estimation method of the electrical resistvity based on non-boiling heat transfer coefficients for exponentially increased heat inputs to the high-Tc test sample in LN2 was developed: exponential heat inputs, Q = Q 0 e t/T, with the periods, T, ranging from 10 ms to 10 s were given to a silver sheathed BiPbSrCaCuO tape in LN2, and electrical current I through the sheathed tape and the terminal voltage V between potential taps on the tape during the transient heating were measured. An empirical equation for the electrical resistance U. of the sheathed tape was obtained as a function of I and T: two constants in the equation were fitted iteratively so that the value of T at each time obtained from the measured values of I and V at the time by using the equation of R may agree with the theoret ical solution of nonboiling heat transfer for the exponential period. The distribution ratio of the electric current through the superconductor and the Ag sheath, I N /I, and the flow resistivity of the superconductor itself were estimated by using this method.

Keywords

Electrical Resistivity Distribution Ratio Natural Convection Heat Transfer Flow Resistivity Transient Heat Transfer 
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

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Copyright information

© Springer Science+Business Media New York 1998

Authors and Affiliations

  • M. Shiotsu
    • 1
  • K. Hata
    • 2
  • A. Sakurai
    • 3
  • C. Suzawa
    • 4
  • S. Isojima
    • 4
  • K. Sato
    • 4
  • T. Fukui
    • 4
  1. 1.Graduate School of Energy ScienceKyoto Univ.Uji, Kyoto 611Japan
  2. 2.Institute of Advanced EnergyKyoto Univ.Uji, Kyoto 611Japan
  3. 3.Future Energy Research Assoc.Sakyo-ku, Kyoto 606Japan
  4. 4.Sumitomo Electric Ind. Ltd.Konohana-ku Osaka 554Japan

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