Design optimization study of the JT-60 superconducting coil modification

Design optimization of the full superconducting coil tokamak JT-60SC is described. Geometries of both toroidal and poloidal field coils have been changed to allow a lower aspect ratio plasma up to A /spl sim/ 2.8. However, the toroidal magnetic field and flux swing capability are kept as close as possible to the original values to sustain a long flattop period under the break-even class plasma condition using the newly-developed superconducting conductors.