Suppression of m=0 modes in an RFP by toroidal field coils

Summary form only given. The Reversatron RFP (reversed field pinch) is normally operated with the toroidal fields coils connected in series. The effects of parallel connected coils has been tested by adding an auxiliary set of 36 coils. These are connected in parallel but are not connected to any supply. The toroidal flux is generated by the series-connected coils which generate voltage but not current in the parallel-connected coils. With the auxiliary coils, the discharge duration is increased from 500 to 550 /spl mu/sec, the plasma current is increased from 50 kA to 60 kA, F is more negative, /spl theta/ is larger, and there is less shot-to-shot variation in the discharges. The m=0 fluctuations measured by 43 surface coils are, however, only slightly reduced.