(Eds.) K.Tachikawa, T.Mito.
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"Studies on Advanced Superconductors for Fusion Device, Part 3 - High-Tc Oxide Superconductors -"
Date of publication:
high-T_c superconductors, material aspects, Bi-based oxide tape, application, Y-based oxide tape, Tl- and Hg-based oxide tapes, ac properties, mechanical tolerance, irradiation effect, current lead, melt processed bulk, magnetic shield
A series of reports on the present status of the development in Nb_3Sn and other advanced metallic superconductors has been published as NIFS-MEM0-20 (March, 1996) and NIFS-MEMO-22 (March, 1997). The third report of this series covers the recent development of different high-T_c oxide superconductors(HTS). Bi-based HTS tapes have been fabricated by powder-in-tube and other processes for power transmission cables operating at 77 K, superconducting magnets operating at 20 K, and ultra high-field insert coils operating at 4.2 K. Coated conductors of Y- and T1-based HTS with improved performance at higher temperatures and fields are being developed. The fabrication of Hg-based HTS with the highest T_c among HTS is also being studied. The ac performance and the mechanical tolerance of HTS, which are the key factors in the practical use, are described in this report. The intenational activities on the standardization of critical current measurement method in HTS tapes has been recently initiated. The irradiation effects on HTS has gained much interests for enhancing flux pinning in HTS. Meanwhile, the melt processed Y- and RE-based HTS bulk materials are being developed as strong permanent magnets. The development of HTS current leads has realized refrigerator-cooled superconducting magnets convenient for broad applications. High performance magnetic shielding facilities have been developed using HTS thick films coated on metal substrates. An appreciable progress in the performance of HTS may be expected through researches on the material science and processing technologies of HTS. The material aspects of HTS are described in detail in this report. Different HTS components, e.g. wires, current leads, magnetic shields, etc., may yield substantial contribution for the progress of fusion technologies in future.