Large coil task of IEA in the development of superconducting magnets for fusion

The huge superconducting magnets will be used in the toroidal field (TF) coils of the next generation Tokamaks like the INTOR. Therefore, the development of the large superconducting TF coils is urgently needed around the world. Under the auspices of the International Energy Agency, IEA, the big project about that now is going on and is called "The Large Coil Task, LCT" The project is carried out within an IEA-Implementing Agreement signed by EURATOM USA, Switzerland and Japan. US-DOE will act as an operating agent and will produce three coils. A facility for testing six coils in a toroidal array is constructed at ORNL. EURATOM, Switzerland and Japan will produce one coil each for testing with US coils. The test coils are designed to be a 2.5 × 3.5 m bore in D-shaped winding and generate a peak field of 8T. A pair of solenoids will be mounted in the bore of the selected coil to generate a pulsed field for the simulation of the effect of the poloidal field on the TF coils. Besides the main parameters of the test coil, there are significant differences among the six coil designs: superconductors (NbTi or Nb3Sn), structural materials, and cooling modes (pool boiling helium or forced flow cooling with supercritical helium gas). The test facility will provide the test stand, vacuum vessel, cryogenics, power supply, and data acquisition systems. The first testing with three pool boiling coils is scheduled to start from July 1982 and the full testing with the six coils from a late half of 1983.