TOKASTAR: A Tokamak Stellarator Hybrid with Possible Bean-Shaped Operation

摘要

A high-beta configuration of low-aspect-ratio Tokamak-stellarator hybrid (named TOKASTAR) with a dee- or bean- shaped cross-section is proposed, which is produced by the application of the outer semi-helical field to the advanced shaped Tokamak plasma. In this configuration, the magnetic local shear near the bad-curvature region of the Tokamak plasma is enhanced by the outer helical field without sufficient change in the average shear. A bean-shaped operation of pure-Tokamak, pure-helical or hybrid configuration is possible in this system. A steady-state high-beta configuration stable to the ballooning mode may be realized by this TOKASTAR concept.