Strain effects of high strength Nb/sub 3/Sn wire reinforced by jelly-rolled Nb/Cu composite and modification of the reinforcement

We are in the process of developing high strength Nb/sub 3/Sn wires reinforced by unique Nb/Cu composites made in a jelly-rolling process to miniaturize high field magnets. A bronze-processed (Nb,Ti)/sub 3/Sn superconducting wire incorporating the composite with a high Nb volume fraction has been made. The wire has shown a high 0.2% proof stress at 4.2 K of 350 MPa. The strain effects such as uni-axial strain dependence and bending strain tolerance on the critical current were examined this time. The influence of the Nb volume fraction in the jelly-rolled composite reinforcement was also investigated to improve the electrical conductivity of the reinforcement.