Design and testing results of the swiss LCT coil

The Swiss contribution to the Large Coil Task at Oak Ridge National Laboratory in Tennessee, U.S.A. is a D-shaped 2.5- × 3.5-m²bore, superconducting toroidal field coil of 8-T field using forced-flow-cooled filamentary NbTi conductor. Switzerland joined this international collaboration in September 1978 and the coil arrived at the International Fusion Superconducting Magnet Test Facility on February 2, 1984. In the summer of the same year the coil was successfully cooled down. The first opportunity to energize the Swiss coil arose in spring 1986 during the ongoing six-coil test. This paper presents the main principles guiding the design, describes the related theoretical calculations, and the supporting experimental program. It discusses the fabrication experience and summarizes the test results obtained to date.