Abstract
The degradation of the critical current of several impregnated and insulated Rutherford type Nb3Sn cables is investigated under an applied transverse load and magnetic field. The cables are made of a new TWCA modified jelly-roll strand material which has been optimized for an extremely high critical current density. The cables have various keystone angles and compaction factors and the dependency of the degradation on these parameters is described. The voltage-current characteristics are determined for the magnetic field ranging from 5 to 11 T and pressure up to 250 MPa. A micro-analysis of the strands is performed before and after the tests to determine possible damage to the filaments. It is found that the initial degradation and subsequent sensitivity to transverse pressure show a strong dependence on the compaction at the narrow edge during cabling. For a cable in which the strands are deformed by 33%, an initial degradation due to cabling is found to be 67%, with a relative degradation of 25% at 150 MPa. For a rectangular cable with a deformation of only 11%, the initial damage is less than 2%, with 3% degradation at 150 MPa. Moreover, the heavily compacted cables tend to show irreversible damage, whereas the less compacted cables show a full recovery.
Keywords
- Critical Current
- Initial Degradation
- Transverse Pressure
- Compaction Factor
- High Critical Current Density
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.
This work was supported by the Director, Office of Energy Research, Office of High Energy and Nuclear Physics, High Energy Physics Division, U.S. Department of Energy, under contract No. DE-ACO3-76SF0098.
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References
H. Boschman, L.J.M. van de Klundert, Effects of transverse stress on the current carrying capacity of multifilamentary wires, Adv. Cryog. Eng. 36A: 93 (1990).
W. Specking, W.Goldacker and R. Fluidger, Effect of transverse compression on I of Nb3Sn multifilamentary wire, Adv. Cryogenic Eng. 34: 569 (1989).
J.W. Ekin, Effect of transverse compressive stress on the critical current and upper critical field of Nb3Sn, J. of Appl. Ph. 62 - 12: 4829 (1987).
H. Boschman, A.P. Verweij, S. Wessel, H.H.J. ten Kate and L.J.M. van de Klundert, The effect of transverse loads up to 300 MPa on the critical currents of Nb3Sn cables, IEEE Trans. on Magn. 27 - 2: 1831 (1991).
B. Jakob and G. Pasztor, Effect of transverse compressive stress on the critical current of cabled Nb3Sn conductor, IEEE Trans. on Magn. MAG-25: 2379 (1989).
H.H.J. ten Kate, B. ten Haken, S. Wessel, J.A. Eikelboom and E.M. Hornsveld, Critical current measurements of prototype cables for the CERN LHC up to 50 kA and between 7 and 13 tesla using a superconducting transformer circuit, in: Proc. MT-11, Tsukuba, Japan, 1989, T Sekingushi, S. Shimmoto, ed., Elsevier Appl. Science, London, N.Y., 60 (1990).
G.B.J. Mulder, H.H.J. ten Kate, H.J.G. Krooshoop and L.J.M. van de Klundert, On the inductive method for maximum current testing of superconducting cables, in: Proc. MT-11, Tsukuba, Japan, 1989, T Sekingushi, S. Shimmoto, ed., Elsevier Appl. Science, London, N.Y., 479 (1990).
A.P. Verweij, De invloed van transversale druk op de spanning-stroom karakteristiek van Nb3Sn-kabels tot 340 MPa en tot 11 T, University of Twente, Enschede, The Netherlands, M.S. Thesis (1990).
H.W. Weijers, Degradatie van de kritieke stroom van Nb3Sn kabels door transversale druk tot 200 MPa in magneetvelden van 9-11 T, University of Twente, Enschede, The Netherlands, M.S. Thesis (1991).
H.H.J. ten Kate, H.W. Weijers and J.M. van Oort, Critical current degradation in Nb3Sn cables under transverse pressure, IEEE Trans. on Appl. Supercond., 3 - 1: 1334 (1993).
J.W. Ekin, Four-dimensional J-B-T-e critical surface for superconductors, Journ. of Appl. Phys., 54 - 1: 303 (1983).
A.Asner, R. Perin, S. Wenger and F. Zerobin, First Nb3Sn, lm long superconducting dipole model magnets for the LHC break the 10 Tesla field threshold, in: Proc. MT-11, Tsukuba, Japan, 1989, T Sekingushi, S. Shimmoto, ed., Elsevier Appl. Science, London, N.Y., 36 (1990).
J.M. van Oort, R.M. Scanlan, H.W. Weijers, S. Wessel and H.H.J. ten Kate, The reduction of the critical current in Nb3Sn cables under transverse loads, IEEE Trans. on Appl. Supercond. 3 - 1: 559 (1993).
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© 1994 Springer Science+Business Media New York
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van Oort, J.M., Scanlan, R.M., Weijers, H.W., ten Kate, H.H.J. (1994). The Reduction of the Critical Current under Transverse Pressure in a New TWCA MJR Cabled Conductor. In: Reed, R.P., Fickett, F.R., Summers, L.T., Stieg, M. (eds) Advances in Cryogenic Engineering Materials . An International Cryogenic Materials Conference Publication, vol 40. Springer, Boston, MA. https://doi.org/10.1007/978-1-4757-9053-5_111
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DOI: https://doi.org/10.1007/978-1-4757-9053-5_111
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