Patent ID: 7210216

Claim:
A method of producing Nb 3 Sn superconducting wire, comprising the steps of: preparing a plurality of rod-shaped Sn modules each obtained by burying a Sn-based metal core in a matrix comprising a first Cu-based metal; preparing a plurality of rod-shaped Nb modules each obtained by burying Nb-based metal filaments in a matrix comprising a second Cu-based metal; bundling the Nb modules and the Sn modules, such that each of the Nb modules surrounds the Sn modules, to obtain an assembly; introducing the assembly into a tubular member comprising a first tube, and a second tube inside the first tube, where the first tube comprises a third Cu-based metal and the second tube comprises Ta-based metal or Nb-based metal, which serves as a diffusion barrier, to obtain a composite; drawing the composite; and heat-treating the composite.