High-field performance of (Nb, Ta)₃Sn superconducting wires fabricated by a new process

Abstract

A thick (Nb, Ta)₃Sn layer can be synthesised in the Ta-Sn core/Nb (Nb-Ta) sheath composite. The diffusion of Nb from the sheath to the core seems to play a key roll to enhance that of Sn from the core to the sheath synthesizing (Nb, Ta)₃Sn layer. In the present study, new Jelly Roll processed (Nb, Ta)₃Sn wires are fabricated using Sn-Ta sheets richer in Sn and Nb sheets. The JR wires exhibit attractive high-field performance, and a small amount of Cu addition to the Sn-Ta sheet effectively decreases the reaction temperature.