Japanese contributions to the procurement of the ITER superconducting magnet

Okuno, Kiyoshi; Nakajima, Hideo; Sugimoto, Makoto; Isono, Takaaki

Japan is expected to make a major contribution to the procurement of the ITER superconducting magnet system. The ITER magnet system consists of 18 TF coils, one CS with six modules and six PF coils. The TF coils and CS have major features in unprecedented size of the magnets and structures and operations at 11 to 13 T high fields that require NbSn superconductor. Because of these features, significant efforts were made towards developing superconducting magnet technology to a level that will allow the ITER magnets to be built with confidence. The construction and testing of the CS and TF model coils have therefore been performed during the ITER Engineering Design Activity (EDA), and all ITER RD goals have been achieved. Based on these achievements, further development activities are now being performed at JAERI in tight collaboration with industry for the preparation of the ITER construction. The activities include analytic studies on design improvement and optimization, manufacturing studies to identify the detailed fabrication processes and tools, and manufacturing demonstrations on full-scale structural components (several tens of tons) such as made of new cryogenic materials, JJ1 and strengthened 316LN. Results from these activities will provide firm technical basis to achieve required performance of the magnets while maintaining both project schedule and cost and to reduce technical risks that may happen during the manufacturing phase.