On the relation between plasma rotation induced by low-frequency resonant magnetic perturbations and transport in ergodic magnetic fields

The penetration of low-frequency resonant magnetic perturbations into a tokamak plasma and their influence on the plasma rotation are analyzed in linear and quaslisinear kinetic approaches. There are two explanations of experimentally observed acceleration of plasma rotation in the direction of the plasma current. First, it is a result of the resonant absorption of the momentum of the perturbation field by the plasma. Second, it is a result of a change in the radial electric field due to the ergodization of the magnetic field and the corresponding increase in the radial electron transport. It is shown that there is no contradiction between these two explanations. These are just two different interpretations of the same phenomenon.