MHD modeling in diverted tokamak configurations

In the advanced tokamak scenarios, plasma performance is strongly limited by the External Kink Mode (EKM) which, coupled inductively with a resistive wall, is transformed in a Resistive Wall Mode (RWM). In this paper we present our contribution to calculations of RWMs in diverted tokamak configurations. By choosing a coordinate system with straight field lines, we have calculated the vacuum field due to the helical perturbation of the EKM, by using the concept of surface currents via the single layer potential theory. The possible presence of a diverted tokamak plasma configuration has been taken into account. Finally, we have calculated the response of a nonuniform resistive wall to an external kink instability of a tokamak, taking toroidal and poloidal plasma rotations with respect to the wall into account.