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

Abstract

Abstract Sumitomo Electric has been developing the silver-sheathed Bi2223 multi-filamentary wires since the discovery of Bi-based superconductors. DI-BSCCO is the superconducting wire with high and uniform critical current properties produced using 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 with length over 2000 m, and recently over 200 A with length over 1000 m were produced successfully, resulting from the improvement and control of the microstructure in Bi2223 multi-filaments. The short trial wires of several meters have exhibited the highest I c over 240 A at 77 K in self-field (corresponding to 580 A per 1 cm-width). Besides, the optimization of carrier density after CT-OP have led to further enhancement of I c, reached 250 A at 77 K in self-field. All the derivative products also have uniform critical current properties over entire length even after lamination with the reinforcing metals. The performances of DI-BSCCO can meet the growing needs for various applications of high temperature superconductor like high in-field applications, such as magnets and motors. The recent progress in transport properties of commercial DI-BSCCO and R&D short trial wires is shown.