DEVELOPMENT OF AG-SHEATHED BI(2223) SUPERCONDUCTING WIRES AND COILS

Silver-sheathed Bi(2223) superconducting wires with long length and hi gh J(c) of over 10(4) A/cm(2) at 77.3 K in a zero magnetic field were developed by using the powder-in-tube method, and the performance of m any application prototypes has progressed. For long wins, a multifilam entary structure is effective for good flexibility and it is easy to h andle the long wire without degradation of superconducting properties. We have fabricated the prototype of a refrigerator-cooled magnet with the react and wind technique. This magnet has been operated at 21 K a nd generated 3.0 T in a 40 phi mm room temperature bore (60 phi mm win ding bore) and 2.5 T continuously for over 150 h.