Long multifilament Bi-2223 Ag-sheathed superconducting tapes and solenoids

Multifilament Ag-sheathed BiPbSrCaCuO (2223) superconducting tapes containing 49 filaments were fabricated by the powder-in-tube route and the roll-anneal process. The transport critical current density Jc was 1.3 x 104 A cm-2 at 77 K and 7 x 104 A cm-2 at 4.2 K in self-field. A 12-m-long tape was used to construct superconducting solenoids (50, 28, and 14 mm internal diameters) generating dc fields 380-1070 G at 4.2 K. Measurements of the variation of Jc with field (0-1.6 T) and bend strain (0-5%) are used to explain the performance of the solenoids. The critical bend strain of tapes was about 1.5%