抄録
Multifilamentary Nb3Sn wires are fabricated starting from Nb/Cu-Sn or Nb/Cu/Sn composites, which facilitates their mass production. Nb3Sn superconducting wires are now one of the key materials in modern science and technology, such as NMR, fusion and refrigerator cooled magnets. Present volume is the special issue on the recent status of mass productionscaled Nb3Sn conductors in Japan. Then this article describes aspects of Nb3Sn conductors, and overviews recent activities in foreign industries. Bronze process and internal tin process are common fabrication process of Nb3Sn multifilamentary wires, whose features are briefly described in this article. The former process is dominantly used in Japan and Europe including Russia, while the latter is rather frequently used in USA, Korea and China. Thus countries are divided into roughly two groups with respect to the major fabrication technology of Nb3Sn. Beside these, Nb tube process and powder-in-tube process are being proceeded in foreign industries. Nb3Sn conductors still have a possibility of improvement in their fabrication technologies, and will continue to contribute for the application of superconductivity.
