Advances in fabrication of Ag-clad Bi-2223 superconductors

Powder-in-tube (PIT) processing was used to fabricate multifilamentary Ag-clad Bi/sub 2/Sr/sub 2/Ca/sub 2/Cu/sub 3/O/sub y/ (Bi-2223) superconductors for various electric power applications. The transport current properties of long lengths of multifilament tapes were enhanced by increasing the packing density of the precursor powder, improving the mechanical deformation, and adjusting the cooling rate. The dependence of the critical current density on magnetic field and temperature for the optimally processed tapes was measured. J/sub c/ was >10/sup 4/ A/cm/sup 2/ at 20 K in magnetic fields up to 3 T and parallel to the c-axis, which is of interest for use in refrigerator-cooled magnets.