The effect of Sn arrangement and intermediate pre-heating on critical current in internal tin processed Nb/sub 3/Sn wires

Internal tin processed Nb/sub 3/Sn wires of different diameters were locally heated before reaction heat treatment. Local heating at an intermediate stage of drawing process decreased the superconducting properties and workability. When the local heating temperatures were lower than the melting point of Sn, non-Cu J/sub c/´s decreased a little compared to non-locally heated wire. But when the local heating temperatures were higher than melting point of Sn, non-Cu J/sub c/´s decreased significantly. This study also suggested it is important that the Sn reservoir be arranged uniformly and is dispersed.