Externally Induced Rotation of the Resistive Wall Modes in RFX-mod

Introduction During the last years, significant progress was made in the control of resistive wall modes (RWMs) in reversed field pinches (RFPs). It was demonstrated on several different devices that static current driven RWMs can be completely suppressed and controlled [1,2]. It is well known that also tokamak advanced scenarios suffer from RWM instabilities. The RWM in a tokamak is typically detached from the wall and rotates together with the plasma. In fact, plasma rotation is one of the most important stabilizing mechanisms present in the tokamak case, though it is expected to be strongly reduced in ITER. This RWM rotation is one of the main differences between tokamaks and RFPs. In RFP plasmas, RWMs are usually detected as non-resonant, wall locked instabilities, and the only possible stabilization strategy is the use of an active coil system.