Superconducting magnet development

Major strides were made during 1986 in the performance of the international Large Coil Task (LCT) program of testing six different superconducting toroidal field coils. The six-coil test array, with a cold mass of 420,000 kg, was cooled to liquid helium temperature; each coil was tested to full design current and magnetic field (8 T); and testing in pulsed fields was begun. Operations and maintenance groups at the International Fusion Superconducting Magnet Test Facility overcame technical problems and achieved a high availability factor for the test facility over most of the year. Coil testing and analysis produced much valuable information. In all six coils, a high degree of quality assurance was achieved. All met LCT specifications, but tests elucidated significant differences, advantages, and disadvantages among the six designs and manufacturing techniques. International collaboration in the LCT work at ORNL continued to be quite effective