Model for plasma response for a finite relative velocity between plasma and a rotating magnetic perturbation

A model is presented which allows the calculation of the torque transferred from a rotating perturbation field to the plasma. It is assumed that the perturbation field induces an electrical current at the singular layer of the plasma. Consistent with results from magnetic braking experiments, it is assumed that a turbulence develops in the current carrying layer such that the anomaly of the plasma resistivity is so large that the plasma can flow resistively through the magnetic islands. Applying the model to the TEXTOR DED case provides a toroidal torque larger than the one of imposed by the neutral beams and thus should be relevant.