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 J_c (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.