Effect of magnetic island geometry on ECRH/ECCD and consequences to the NTM stabilization dynamics

Abstract

In the majority of codes that model ECCD-based NTM stabilization, the analysis of the EC propagation and absorption is performed in terms of the axisymmetric magnetic field, ignoring effects due to the island topology. In this paper, we analyze the wave propagation, absorption and current drive in the presence of NTMs, as well as the ECCD-driven island growth, focusing on the effect of the island geometry on the wave deposition. A primary evaluation of the consequences of these effects on the NTM evolution is also made in terms of the modified Rutherford equation. © Owned by the authors, published by EDP Sciences, 2012.