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Local Measurement of Current Density by Magneto-Optical Current Reconstruction in Normally and Overpressure Processed Bi-2223 Tapes

S. Patnaik·D. M. Feldmann·A. Polyanskii·Y. Yuan·J. Jiang·X. Y. Cai·E. E. Hellstrom·D. C. Larbalestier·Y. Huang
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Abstract

Magneto-optical current reconstruction has been used for detailed analysis of the local critical current density (Jc) variation in monocore Bi-2223 tapes. We find, even in high quality tapes with bulk transport Jc ~ 40 kA/cm^2 (77K, 0T), that there exist local regions which possess current densities of more than 200 kA/cm^2. Overpressure processing at 148 bar significantly improved Jc to 48 kA/cm^2 by improving the connectivity. For the overpressure-processed sample we find that the current distribution is more uniform and that the maximum local current density at 77 K is increased almost to 300 kA/cm^2.

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S. Patnaik, D. M. Feldmann, A. Polyanskii, Y. Yuan, J. Jiang, X. Y. Cai, E. E. Hellstrom, D. C. Larbalestier, Y. Huang. 2002-08-16. Local Measurement of Current Density by Magneto-Optical Current Reconstruction in Normally and Overpressure Processed Bi-2223 Tapes. https://doi.org/10.1109/tasc.2003.812056

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