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Field Orientation Dependence of Losses in Rectangular Multifilamentary Superconductors

  • J. H. Murphy
  • W. J. CarrJr.
  • M. S. Walker
  • P. D. Vecchio
Part of the Advances in Cryogenic Engineering book series (ACRE, volume 22)

Abstract

The need for low-loss, stable, high current density superconducting windings has led to the development of twisted multifilament composite superconductors. For coils with high packing density that are capable of withstanding mechanical loading, the composites are often made rectangular in cross section, and the capability for production of conductors with high aspect ratios has been developed. Tapes of twisted multifilament Nb3Sn composites are in fact now being made in order to reduce the strain in the filaments during winding[1].

Keywords

Relative Permeability Mixed Matrix Eddy Current Loss High Packing Density Field Coil 
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.

Notation

a

length of semimajor axis for the outermost filaments

a

unit vector

b

length of semiminor axis for the outermost filaments

ƒ

frequency of alternating magnetic field

H

magnetic field vector

HA

applied magnetic field

H0

bias magnetic field

L

twist pitch

Nx Ny

demagnetizing factors for conductor stacking

P

total power loss

Pe

eddy current power loss

t

time

T

temperature of sample

u,v,w

lengths of the stacked sample along cartesian axes

V

volume

x, y, z

cartesian coordinates

Greek symbols

a,ß

constants

λsc

local fraction superconductor

μ

relative permeability for fields transverse to the filament axis

μ

permeabihty of free space, 4πx10−7

θ

angle measured from conductor major axis to the magnetic field vector H

ω

f, angular frequency of alternating magnetic field

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References

  1. 1.
    E. Gregory, W. G. Marancik, and F. T. Ormond, IEEE Trans. Magn. MAG-11(2):295 (1975).CrossRefGoogle Scholar
  2. 2.
    W. J. Carr Jr., J. Appl. Phys. 45:929 (1974).CrossRefGoogle Scholar
  3. 3.
    M. N. Wilson, C. R. Walters, J. D. Lewin, and P. F. Smith, J. Phys. D Appl. Phys. 3:1517 (1970).CrossRefGoogle Scholar
  4. 4.
    G. H. Morgan, J. Appl. Phys. 41: 3673 (1970).CrossRefGoogle Scholar
  5. 5.
    G. Reis and H. Brechna, Pub. KFK1372, Institut für Experimentelle Kernphysik, Karlsruhe, Germany (1972).Google Scholar
  6. 6.
    W. J. Carr Jr., M. S. Walker, and J. H. Murphy, J. Appl Phys. 46:4048 (1975).CrossRefGoogle Scholar
  7. 7.
    J. A. Osborn, Phys. Rev. 67:351 (1945).CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1977

Authors and Affiliations

  • J. H. Murphy
    • 1
  • W. J. CarrJr.
    • 1
  • M. S. Walker
    • 1
  • P. D. Vecchio
    • 1
  1. 1.Westinghouse Research LaboratoriesPittsburghUSA

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