A NEW METHOD FOR JOINING OF BI(2223) AG TAPES

A superconducting joint between Bi(2223)/Ag-sheathed tapes has been fa bricated with approximately 90% of the current capacity of the tape it self. The silver sheath was mechanically or chemically removed from on e side of each tape without disturbing the superconducting core. The e xposed superconducting cores of the two tapes are brought into contact , wrapped up with a thin silver foil, and pressed so as to again seal the superconductor in a silver sheath. Then a series of different reac tion anneal and mechanical treatments were performed on the joined tap es to obtain an optimum heat-treatment condition. The optical microgra phs of a longitudinal section of the entire joint shows that there is no constriction of the superconducting core throughout the joint. (C) 1998 Elsevier Science B.V.