The effect of resonant magnetic perturbations on L and H-mode plasmas on MAST

Abstract Experiments have been performed on MAST using in-vessel (n = 3) resonant magnetic perturbation coils. The application of the RMPs to L-mode discharges has shown a clear density pump out when the pitch angle at the low field side of the plasmas is well aligned with the coils. The size of the pump out is correlated with the resonant component of the applied field. The toroidal rotation of the plasma does not affect the size of the density pump out. In type I ELM-ing H-mode discharges at a particular value of q95 the ELM frequency can be increased by a factor of 5 by the application of the RMPs. This effect on the ELMs is not correlated with the width of the region for which the (vacuum field) Chirikov parameter is greater than 1 but may be correlated with the size of the resonant component of the applied field.