A new symmetrical arrangement of tape-shaped multifilaments for Bi-2212/Ag round-shaped wire

A new Bi-2212/Ag found-shaped wire with tape-shaped multifilaments has been successfully developed. The wire includes 126-960 tape-shaped Filaments with triple rotation symmetry, having a good crystal alignment in each filament. We refer the the new wire at ROSATwire, (ROtation-Symmetric Arranged Tape-in-tube wire). Since the ROSATwire structure yields complete symmetrical arrangement of the tape-shaped filaments. it is eliminates the need of a rolling machine, but allows us to use a drawing or extrusion machine. We found that the present wire fabrication process markedly improves not only productivity and lowers cost, but also enhances the transport J(c) of the Bi-21212/Ag wire. The I-c and J(c) reached >340A and 1000A/mm(2) at 28T and 4K.