Jc distribution in the Bi-2223/Ag-AgMg tapes

Bismuth-based, silver-sheathed tapes are considered to have great possibilities for electric power applications. Remarkable progress in Bi-2223/Ag tapes has been made in the world. We also have been developing Bi-2223/Ag tape since 1989, and we can fabricate 1 km length tape now. One of the important properties for J(c) of Bi-2223/Ag tape is the distribution in the cross-section of tape, as well as that of longitudinal distribution. We measured J(c) distribution in the cross-section of tapes that were cut in the constant period from the edge of tape by using laser beam. It was cleared that J(c) increased periodically toward the center of the tape but J(c) slightly decreased at the center. We consider that J(c) distribution in the tape has good correlation with the density of filament. By this result, we succeeded in manufacturing the long Bi-2223/Ag-AgMg tape of J(c) = 31000 A/cm(2) and J(e) = 8000 A/cm(2). Furthermore, we achieved I-c = 50 A in Bi-2223/Ag-AgMg twisted long tape. (C) 2001 Elsevier Science B.V. All rights reserved.