Sn-Ta (-Cu) alloys with enough ductility to be fabricated into a thin sheet were synthesized by melting a mixture of Sn+Ta (+Cu) powder. The (Nb, Ta)3Sn wires were prepared by Jelly Roll (JR) process and filamentary process. In the JR process a Sn-Ta (-Cu) sheet was laminated with a Nb sheet and wound into a JR composite. In the filamentary process a Sn-Ta (-Cu) sheet was wrapped around Nb-1 at%Ta rods and bundled into a filamentary composite. Both composites were fabricated into wires without intermediate annealing and then heat treated. The composition and micro-structure of (Nb, Ta)3Sn layers formed in the wires were studied. Ta in the sheet improves the high-field performance, while Cu addition to the sheet decreases the reaction temperature of the wire. The non-Cu Jc of the JR wire without Cu addition to the sheet and reacted at 900°C is about 1.0×108 A/m2 at 23 T and 4.2 K. A nearly the same non-Cu Jc of the wire is obtained at 25 T and 2.1 K, the upper critical field of the wire being about 28.5 T. The JR wire and 13-core filamentary wire with a few mass% Cu addition to the sheet and reacted at 800°C show a non-Cu Jc of about 1.0×108 A/m2 at 22 T and 4.2 K. Both wires exhibit a n value of about 30 at 22-23 T and 4.2 K, which represents a potentiality of the wires for high magnetic field use.
