Design study of national centralized tokamak facility for the demonstration of steady state high beta plasma operation

Design studies are shown on the National Centralized Tokamak facility, NCT (formerly called JT-60SC). The machine design is carried out to estimate the capability for the flexibility in aspect ratio and shape controllability for the demonstration of the high-β steady state operation with nation-wide collaboration, in parallel with ITER towards DEMO. Two designs are proposed and assessed with respect to the physics requirements such as confinement, stability, current drive, divertor, and energetic particle confinement. The operation range in the aspect ratio and the plasma shape is widely enhanced in consistent with the sufficient divertor pumping. Evaluation of the plasma performance towards the determination of machine design are presented. (author)