High-field superconducting properties of the composite-processed Nb3Sn with Nb-Ti alloy cores

Abstract

The Nb3Sn layer growth rate, the upper critical field and the critical current density in high fields of the composite-processed Nb3Sn are greatly enhanced by the titanium addition to the niobium core. This addition yields a Jc (Nb3Sn layer) value of over 1×105 A/cm2 at 15 T. After the reaction, large amount of titanium is incorporated into the Nb3Sn layer. The optimal amount of titanium addition to the niobium core is about 2 at. %. The Nb-Ti/Cu-Sn composite wire seems to be quite promising for applications in magnetic fields up to at least 15 T.