Fabrication of multifilament Nb3Sn conductors

Abstract

Multifilament conductors have been fabricated using niobium tubes with a sheathed tin-copper alloy inside and pure copper matrix outside. These composites have good workability, cold drawn without any intermediate heat treatment. Sample evaluation has included measurements of critical temperature, resistivity, and critical current density. The Nb3Sn formed by this method has much higher critical current density than the previous one with approximately the same tin concentration (12 at.%), but lies on the line extrapolated from the bronze method over the solid solubility limit.