Edge Plasma Structure with Rotating Resonant Magnetic Perturbations at TEXTOR

Rotating Resonant Magnetic Perturbations impose a characteristic modulation to the electron density and temperature in the TEXTOR plasma edge ($r/a>0.9$). The modulation matches the position of the magnetic topology modeled in vacuum approximation for low relative rotation of $f_{rel}=-0.2\,kHz$ between RMP field and toroidal plasma rotation. With increasing relative rotation ($f_{rel}=1.8\,kHz$), the plasma structure at the outermost rational flux surface is shifted by $\pi/2$ in counter-$B_t$ direction due to internal plasma response. The shift is correlated to a smaller displacement of the plasma structure in front of the RMP coils of $0.1\pi$. This indicates a competition between the near-field of the RMP coils and the net magnetic field at the rational flux surface.