Development of Nb_3Sn superconducting wires for high field magnets at Kobe Steel and JASTEC

摘要

Research and development activities and some recent results related to Nb_3Sn superconducting wires in Kobe Steel, Ltd. (KSL) and Japan Superconductor Technology Inc. (JASTEC) are introduced. First, an outline of the activities is described briefly from a historical point of view. Following that, improvements in the characteristics (i.e., critical current density (J_c), n-value and mechanical properties) of bronze-processed Nb_3Sn wires are reviewed. Finally, the status of development for the Ta-Sn powder-in-tube (TS-PIT) process is briefly discussed.