HIGH-T-C SUPERCONDUCTING CURRENT LEADS

Metal-sheathed high-T-c superconducting current leads of J(c) = 1.6-1. 8 x 10(4) A cm(-2) at 77 K under self-field condition were fabricated using a modified short tape processing technique. It was found that se ction-wise uniaxial pressing can be used to provide the necessary inte rmediate mechanical deformation between heat treatments of long silver -sheathed (Bi,Pb)(2)Sr2Ca2Cu3O10+x superconductor. The overlapping of pressing up to 400 MPa does not impose non-uniformity of transport J(c ) to the final product. By stacking of single-core tapes, multi-layer current leads can be made. The I-c of this multi-layer current lead is additive, as in normal current in parallel-connected circuits. There is a lateral variation of J(c) in the superconducting core of these le ads. (C) 1998 Elsevier Science B.V. All rights reserved.