Magnetic Characteristics and Measurements of Filamentary Nb-Ti Wire for the Superconducting Super Collider
In synchrotron accelerator applications, such as the Superconducting Super Collider (SSC), superconducting magnets are cycled in magnetic field. Desirable properties of the magnets include field uniformity, field stability with time, small residual field, and fairly small energy losses upon cycling. This paper discusses potential sources of problems in achieving these goals, describes important magnetic characteristics to be considered, and reviews measurement techniques for magnetic evaluation of candidate SSC wires. Instrumentation that might be practical for use in a wire-fabrication environment is described. We report on magnetic measurements of prototype SSC wires and cables and speculate on causes for instability in multipole fields of dipole magnets constructed with such cables.
KeywordsDipole Magnet Hysteresis Loss Filament Diameter Flux Creep Flux Jump
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- 3.M. N. Wilson, “Superconducting Magnets,” Oxford University Press, Oxford, U.K. (1983), pp. 171–174.Google Scholar
- 4.M. N. Wilson, “Superconducting Magnets,” Oxford University Press, Oxford, U.K. (1983),, pp. 139–140, pp. 194–197, p. 308.Google Scholar
- 6.E. W. Collings, Stabilizer design considerations in fine-filament Cu/NbTi composites, Adv. Cryo. Engr. (Materials) 34:867 (1988).Google Scholar
- 8.D. A. Herrup, M. J. Syphers, D. E. Johnson, R. P. Johnson, A. V. Tollestrup, R. W. Hanft, B. C. Brown, M. J. Lamm, M. Kuchnir, and A. D. Mclnturff, Time variations of fields in superconducting magnets and their effects on accelerators, IEEE Trans. Magn. 25:1643.Google Scholar
- 9.R. W. Hanft, B. C. Brown, D. A. Herrup, M. J. Lamm, A. D. Mclnturff, and M. J. Syphers, Studies of time dependence of fields in Tevatron superconducting dipole magnets, IEEE Trans. Magn. 25:1647.Google Scholar
- 10.M. Kuchnir and A. V. Tollestrup, Flux creep in a Tevatron cable, IEEE Trans. Magn. 25:1839.Google Scholar
- 15.M. N. Wilson, Electronic integration technique for measuring magnetization of hysteretic superconducting materials, Rev. Sci. Instrum. 36, pp. 243–245.Google Scholar
- 16.P. J. Flanders, Instrumentation for magnetic moment and hysteresis curve measurements, in: “Conference on Magnetism and Magnetic Materials,” American Institute of Electrical Engineers, New York (1957), T-91, pp. 315–317.Google Scholar
- 21.J. A. Good, A variable temperature high sensitivity SQUID magnetometer, in: “SQUID: Superconducting Quantum Interference Devices and their Applications,” H. D. Hahlbohm and H. Lübbig, eds., Walter de Gruyter, Berlin (1977), pp. 225–238.Google Scholar
- 29.E. W. Collings, K. R. Marken Jr., M. D. Sumption, R. B. Goldfarb, and R. J. Loughran, AC loss measurements of two multifilamentary NbTi composite strands, paper AY-05, this conference.Google Scholar
- 30.D.-X. Chen and R. B. Goldfarb, Kim model for magnetization of type-II superconductors, J. Appl. Phys. 66:2510 (1989).Google Scholar
- 33.M. N. Wilson, Flux creep and activation energies at the grain boundaries of Y-Ba-Cu-O superconductors, Phys. Rev. B 39, pp. 176–181. (1989).Google Scholar