The effect of intermediate deformation by eccentric rolling on the J(c)(B)performance of multicore Bi-2223/Ag tapes

An eccentric rolling (ER) technique has been applied during the intermediat e deformation of commercial multicore Bi-2223/Ag tapes. The J(c)(B) perform ance of the tapes deformed by ER and standard 2-high rolling technique (FR) have been compared. It was shown, that at 77 K, the self-field J(c) can be increased by 12.6% and J(c)(1 T) by 21% if an optimum ER deformation is ap plied. The tapes subjected to ER show smaller J(c) drop in low magnetic fie lds (B-ex < 0.2 T) as a consequence of reduced number of transverse cracks and improved filament density. This is a vital aspect for further J(c) impr ovements by an optimal ER intermediate deformation applied for multicore Bi -2223/Ag tapes. ER tapes also have lower J(c)-anisotropy ratio at B-ex = 0. 5 T than FR ones: which may be advantageous to HTS coil manufacturers for v arious applications. (C) 2001 Elsevier Science B.V. All rights reserved.