Nb (3) Sn superconducting wire capable of obtaining high critical current density and method for producing the same

摘要

PROBLEM TO BE SOLVED: To provide an Nb3 Sn superconductive wire member in which compactness can be realized when it is applied to a superconductive magnet, and in which a high critical current density can be obtained at a magnetic field of 11T or more, a manufacturing method thereof, and a superconductive magnet using the Nb3 Sn superconductive wire member. SOLUTION: For an Nb3 Sn superconductive wire member in which plural filaments of Nb or Nb alloy are embedded in base material comprising Cu-Sn base alloy, the diameter of the filament is 3 m or less in the case where the material is used in a magnetic field of 11-18T, and the diameter of the filament is 3-8 m in the case where it is used in a magnetic field of 18T or more. In manufacturing the Nb3 Sn superconductive wire member, a coil to form a magnetic field of 11-18T is heat-treated at 600-700 deg.C, and a coil to form a magnetic field of 18T or more is heat-treated at 700-800 deg.C for obtaining a higher critical current density.