Abstract: A precursor for fabricating a Nb3Sn superconducting wire by an internal Sn process includes one or a plurality of stabilizing copper portions collectively disposed in the center, each stabilizing copper portion being provided with a diffusion barrier layer in the periphery thereof, and a superconducting matrix portion disposed so as to surround the one or the plurality of stabilizing copper portions, the superconducting matrix portion including a Nb or Nb-based alloy core and a Sn or Sn-based alloy core embedded in a Cu or Cu-based alloy matrix.

Abstract: A method for producing an Nb3Sn superconductive wire material using a powder process is provided, in which a powdered raw material is filled in a sheath made of Nb or an Nb-based alloy, and the above sheath is subjected to diameter reduction to form a wire, followed by heat treatment to form a superconducting layer at the interface between the sheath and the filled powder. The above powdered raw material contains powdered Sn, powdered Cu, and a powdered alloy or a powdered intermetallic compound, which is formed from Sn and at least one metal selected from the group consisting of Ti, Zr, Hf, V, and Ta.

Abstract: A precursor for manufacturing a Nb3Sn superconducting wire according to the present invention includes a mono-element wire including a Sn or Sn-based alloy core disposed at the, a Cu or Cu-based alloy matrix and a plurality of Nb or Nb-based alloy filaments surrounding the Sn or Sn-based alloy core, and a diffusion barrier layer and a stabilizing copper layer surrounding the Cu or Cu-based alloy matrix. In a final shape after a reduction process, the average diameter of the Nb or Nb-based alloy filaments is set to 5 ?m to 30 ?m, and the average distance between the Sn or Sn-based alloy core and the Nb or Nb-based alloy filaments nearest the Sn or Sn-based alloy core is set to 100 ?m or less.

Abstract: Disclosed is a manufacturing method of an Nb3Sn superconductive wire using a powder technique, the method including the steps of: filling, as a raw powder, an intermetallic compound powder obtained from a metallic powder containing at least one metallic powder selected from Ta powder and Nb powder, and Sn powder, or a mixture of the metallic powder and the Sn powder into a sheath made of Nb or an Nb based alloy; performing a diameter-reduction process on the sheath to form a wire; heat treating the wire; and, forming a superconductive layer on the interface between the sheath and the powder, wherein at least one of the metallic powders selected from the Ta powder and the Nb powder is obtained by aggregating fine particles (primary) in shape of coral to form secondary particles.

Abstract: A precursor for manufacturing a Nb3Sn superconducting wire by bronze method, in which plural Nb or Nb-based alloy cores are buried in a Cu—Sn-based alloy base material. The Cu—Sn-based alloy base material comprises Ti and/or Zr in addition to Sn, and these components satisfy the equations (1) and (2) below: 0.4?(X?15.6)/Y?1.9??(1) and 15.6<X?19 ??(2) where the symbol X denotes the content of Sn in mass % and the symbol Y denotes the total content of Ti and Zr in mass %.

Abstract: A bobbin for a superconducting coil includes a cylindrical drum, and a tapered portion extending from each end of the drum. A superconducting wire or a precursor of the superconducting wire shaped like a tape is helically wound around the drum in multiple layers. The tapered portion has a tapered surface that is inclined at an arbitrary angle.

Abstract: A method for manufacturing a powder-metallurgy processed Nb3Sn superconducting wire is provided. In the method, a sheath made of Nb or a Nb alloy is filled with a raw material powder containing Sn. The sheath filled with the raw material powder is subjected to diameter reduction to form a wire. The wire is heat-treated to form a superconducting phase at the internal surface of the sheath. The raw material powder is prepared by adding a Sn powder to a Cu—Sn alloy powder or a Cu—Sn intermetallic compound powder, and is compacted under isotropic pressure.

Abstract: A method for fabricating a Nb3Sn superconducting wire includes the steps of loading or inserting a core material containing at least Sn into a pipe member made of Nb or a Nb alloy, inserting the pipe member into a Cu billet to form a composite member, subjecting the composite member to diameter reduction, and then heat-treating the composite member to form a Nb3Sn superconducting layer from the inner surface of the pipe member, wherein, in the pipe member made of Nb or the Nb alloy after the diameter reduction, the average crystal grain size is 0.1 to 2 ?m, and preferably, the total concentration of oxygen, nitrogen, and carbon is 120 ppm or less.