The effects of the stellarator windings located on the large-major-radius side of the tokamak are studied experimentally. The strong focussing effect provided by the stellarator field significantly improves positional stability.
An idea is suggested which leads to a significant reduction in the required number of toroidal field coils and to a dramatic improvement in access for tokamak maintenance and diagnostics. It is found that a two or four coil system may be practical. The basic concept is presently being used for designing RST (Radio Frequency Driven, Steady-State Tokamak) of General Atomic Company.