High critical current densities in long lengths of mono- and multifilamentary Ag-sheathed Bi(2223) tapes

By optimizing the tape fabrication process, high critical current densities over long length (up to 25 m) of Bi,Pb(2223) Ag-sheathed tapes were reproducibly obtained. The critical current densities of multifilamentary tapes (up to 55 filaments) are typically in the range of 25-30 kA/cm/sup 2/. At 77 K, up to 35 kA/cm/sup 2/ were recently measured for a monofilamentary tape of 0.5 m length. Detailed measurements of the transport properties of these tapes as well as of test pancakes and currents leads will be presented.