Recent R&D progress on DI-BSCCO wires with high critical current properties

Abstract Sumitomo Electric has been developing the silver-sheathed Bi2223 multi-filamentary wires since the discovery of Bi-based superconductors. DI-BSCCO is the high performance wires produced with the controlled-overpressure (CT-OP) sintering technique. The present commercial DI-BSCCO can provide the uniform high critical current, I c , up to 180 A over 2000 m, and recently 200 A were succeeded to obtain with the same kind of 1000 m-long wires, resulting from the improvement and control of the microstructure in Bi2223 multi-filaments. The short trial wires of several meter have exhibited over 240 A as the highest I c at 77 K, self-field (corresponding to 580 A per 1 cm-width) according with high T c over 112 K. Besides, the optimization of carrier density after CT-OP led to further enhancement of I c , reaching 250 A. All the derivative products have also uniform critical current property over the entire length even after lamination with the reinforcements. The performances of DI-BSCCO can meet the growing needs for various high temperature superconducting applications involving high in-field properties, such as magnets and motors. The recent progress on I c including in-field properties along with the remarkable findings on the performances of DI-BSCCO will be shown.