PRECURSOR OF POWDER-METHOD Nb3Sn SUPERCONDUCTING WIRE ROD, AND POWDER-METHOD Nb3Sn SUPERCONDUCTING WIRE ROD

摘要

There is provided a Nb 3 Sn superconducting wire having excellent superconducting properties, the wire being produced by a powder process, and a precursor of the Nb 3 Sn superconducting wire produced by a powder process, the precursor being capable of increasing the efficiency of the formation reaction of Nb 3 Sn even in a relatively low practical temperature range of about 600°C to about 750°C. The precursor of the present invention is a precursor of a Nb 3 Sn superconducting wire produced by a powder process including filling a sheath containing at least Nb with a material powder containing at least Sn, subjecting the resulting sheath filled with the powder to diameter reduction to form a wire, and subjecting the resulting wire to heat treatment to form a superconducting layer at the interface between the sheath and the powder. The material powder contains a Cu component. The sheath has a structure in which a Nb or Nb-based-alloy portion is combined with a Cu or Cu-based-alloy portion.