Experimental observations of plasma response to Resonant Magnetic Perturbation on TEXTOR

The plasma response to a resonant magnetic perturbation (RMP) is experimentally measured on the TEXTOR tokamak using a fast movable magnetic probe. It is shown that, due to the plasma response, the magnetic field significantly differs from the vacuum field. Clear linear and non-linear responses to RMP are observed by varying the intensity of these perturbations or the plasma edge safety factor. Both the radial profile evolution and the dependence of plasma response on the edge safety factor show a stronger resonant effect when the RMP rotates at 5 kHz in the counter-current direction