Development of Bi-2212/Ag round-shaped wire and magnet application

Recent achievements in the newly-developed Bi-2212/Ag round-shaped wire with tape-shaped multifilaments are summarized. The new round-shaped wire includes 126-1320 tape-shaped filaments with triple rotation symmetry, having a good crystal alignment of Bi-2212 in each filament. We refer to the new wire as ROSATwire, (ROtation-Symmetric Arranged Tape-in-tube wire). The ROSATwire fabrication process markedly improved productivity and lowered the cost, and also improved the transport Jc of the wire. The Ic and Jc reached values greater than 340 A and 1000 A mm-2 , respectively, at 28 T and 4 K. Insulated wires of over 400 m length, 2 mm in diameter, are now available and ready for magnet winding. Several solenoid magnets with a 130-160 mm outer diameter and 100-600 mm height are now under fabrication. (author)