Superconducting magnet development in Japan

The present state of R & D works on the superconducting magnet and its applications in Japan are presented. On electrical rotating machines, 30 MVA superconducting synchronous rotary condenser (Mitsubishi and Fuji) and 50 MVA generator are under construction. Two ways of ship propulsion by superconducting magnets are developing. A superconducting magnetically levitated and linear motor propelled train "MAGLEV" has developed by the Japan National Railways (JNR). A large scale test track of 7 Km was constructed in Kyushu and the test vehicle reached its target speed of 517 Km/hr. The first manned test running was made by three-vehicles train on new U-shaped guideway. The superconducting magnet development for fusion is the most active field in Japan. The Cluster Test program has beer demonstrated on a 10 T Nb3Sn coil and the first coil of Large Coil Task in IEA collaboration has been constructed and the domestic test was completed in JAERI. These works are for the development of toroidal coils of the next generation tokamak machine. R & D works on superconducting ohmic heating coil are in progress in JAERI and ETL. The latter group has constructed 3.8 MJ pulsed coil. A high ramp rate of changing field in pulsed magnet, 200 T/s, has been tested successfully, for burning tokamak device project in IPP, by joint work of Nihon University, ETL, Mitsubishi and IPP. High Energy Physics Laboratory (KEK) are conducting active works. The superconducting μ meson channel and π meson channel have been constructed and are operating successfully. KEK has also a project of big accelerator named "TRISTAN", which is similar to ISABELLE project of BNL. Superconducting synchrotron magnets are developed for this project. The development of superconducting three thin wall solenoid has been started. One of them, CDF, is progressing under USA-Japan collaboration.