Self-field Effects on JC(B,T) Measurements of Nb-Ti Strands in High Magnetic Fields

Ridgeon, F.J.; Raine, M.J.; Lakrimi, M.; Thomas, A.; Boutboul, T.; Hampshire, D.P.

Abstract

We have investigated the applied magnetic field, temperature, and self-field dependence of the critical current density of a Nb-Ti strand produced for the ITER Poloidal Field conductor. Measurements were made on a standard ITER barrel in magnetic fields from 4.0 to 8.0 T and temperatures from 3.5 to 6.0 K. We investigated the effect of self-field by changing the direction of the transport current, resulting in an inward or outward Lorentz force acting on the strand. At 4.2 K and 5 T, the difference in the measured JC between the two Lorentz force polarities was about 1%. From this low value, we conclude that self-field effects in the Nb-Ti strand are about 40 % of those expected using standard self-field calculations for fully transposed multifilamentary strands, consistent with theoretical considerations for annular filament transposition.

Citation

Ridgeon, F., Raine, M., Lakrimi, M., Thomas, A., Boutboul, T., & Hampshire, D. (2018). Self-field Effects on JC(B,T) Measurements of Nb-Ti Strands in High Magnetic Fields. IEEE Transactions on Applied Superconductivity, 28(4), Article 9001805. https://doi.org/10.1109/tasc.2018.2808370

• Journal Article Type: Article
• Acceptance Date: Feb 7, 2018
• Online Publication Date: Feb 21, 2018
• Publication Date: Jun 1, 2018
• Deposit Date: Feb 8, 2018
• Publicly Available Date: Mar 23, 2018
• Journal: IEEE Transactions on Applied Superconductivity
• Print ISSN: 1051-8223
• Electronic ISSN: 1558-2515
• Publisher: Institute of Electrical and Electronics Engineers
• Peer Reviewed: Peer Reviewed
• Volume: 28
• Issue: 4
• Article Number: 9001805
• DOI: https://doi.org/10.1109/tasc.2018.2808370
• Public URL: https://durham-repository.worktribe.com/output/1339543
• Related Public URLs: http://ieeexplore.ieee.org/document/8298512/