Processing and Critical Currents of Silver-Sheathed Bismuth-Based Superconducting Wires and Tapes

Wires and tapes of bismuth-based superconductors (e.g BSCCO) have been produced by the standard powder in tube technique, using Ag sheaths. Different geometries of samples have been processed, including single core wires, multi-filamentary wires and tapes. For each configuration, both straight samples and coils have been prepared and electrically characterized at 77K at zero field and at 4.2K in magnetic fields up to 15 T. At 77K, straight samples exhibit critical current densities up to 8000 A/cm exp 2 at zero magnetic field and up to 75 000 A/cm exp 2 at 4.2K. Due to a very weak field dependence, J sub c at 4.2K at 15 T is still higher than 20 000 A/cm exp 2 .