AC-Losses of a Prototype 10 kA Cable-in-Conduit NbTi Superconductor for SMES Applications
We measured the hysteresis and coupling losses of a prototype braided and twisted NbTi cable-inconduit superconductor for direct cooling by supercritical He. The conductor has been designed for a 180 MJ magnetic energy storage model coil with Bmax = 5.4 T at Imax = 10 kA. We also measured separately the ac losses of the subcables and of the basic NbTi multifilament strands. A chromium coating of the strands reduced the coupling losses in the cable considerably. We also determined the influence of cable void fraction on the coupling losses. Concerning a further potential ac loss reduction it turns out, that for our envisaged coil discharge velocity it would be necessary to reduce the hysteresis losses in the filaments.
KeywordsVoid Fraction Loss Reduction Chromium Coating Coupling Loss Steel Jacket
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- 1.L.J.M. van de Klundert, Proceedings of the International Symposium on AC Superconductors,Smolenice, CSFR, 24 (1991).Google Scholar
- 2.K. Kwasnitza and Ch. Widmer, Proceedings of the International Symposium on AC Superconductors, Smolenice, CSFR, 58 (1991).Google Scholar
- 3.A. Eikelbohm, Twente University, Enschede, Thesis “AC Losses in Prototype Conductors for the NET Toroidal Field Coils”.Google Scholar
- 4.J.M. Mower and Y. Iwasa, “Advances in Cryogenic Engineering”, Vol. 32, Plenum Press New York, 771 (1986).Google Scholar
- 6.To be submitted by the authors to Cryogenics.Google Scholar