Results of ITER Superconducting Magnet R&D

The ITER magnets are among the most time-critical of the tokomak components. Over the last two years, as well as finalising the magnet design, the final elements of the magnet R&D have been completed. These elements include the resolution of the Nb3Sn strand performance degradation reported for some conductor samples, the PF conductor performance demonstration in the PF insert coil, the CS conductor jacket, the studies of radiation resistant insulation, a basic demonstration of the performance of the uniaxial glass fibre precompression rings (an important element in the TF coil out of plane support) and 68 kA HTS current leads. The focus of the work is now moving to qualification of components made under industrial conditions, the qualification of processes and tooling and the fabrication process optimisation to reduce costs. First in this respect are the fabrication routes for the TF coil radial plates and structures, and the design/manufacture of the TF coil winding, transfer and insulation tooling. Overall the progress in the work shows that a satisfactory performance of Nb3Sn conductor could be reached; and the manufacture feasibility of the ITER magnet is confirmed.