ECRH EXPERIMENTS ON TEARING MODE PHYSICS AT TEXTOR
Combining the potential of ECRH, ECE-Imaging and the generation of resonant magnetic perturbations (RMP) by the dynamic ergodic divertor provide new insights into the physics of tearing modes. ECE-I measurements reveal the two dimensional propagation of heat pulses around magnetic islands. Inside an island with a flat temperature profile, the electron heat transport is shown to be strongly reduced with respect to the surrounding plasma. ECRH or co-ECCD localized at the resonant surface is found to lead to a higher threshold for the penetration of RMP. Analysis of the generalized Rutherford equation shows that under TEXTOR conditions the heating effect dominates over the effect of current drive in agreement with the experimental observations. On ITER, both are expected to be of the same order of magnitude.
