PLASMA ROTATION IN A RIPPLED-FIELD TOKAMAK IN THE ABSENCE OF A FAST-ION BEAM

A theory is developed for the plasma rotation in a rippled-field tokam ak under the conditions corresponding to the banana regime. In contras t with the previous study by Mikhailovskii [4], it is assumed that the fast-ion beam that gives rise to the plasma rotation is absent. In th is case, the plasma rotation is shown to be governed by the ripple-ind uced thermal force, i.e., by the temperature-gradient dependent compon ent of the frictional force related to collisions between the circulat ing and locally trapped ions. The drift kinetic equation is used to de rive analytical expressions both for the ripple-induced thermal force and for the ''velocity'' component of this frictional force, i.e., for the component that is proportional to the difference between the mean velocities of the circulating and locally trapped ions. From the cond ition that this component of the frictional force is equal to zero an expression for the equilibrium toroidal velocity of the plasma is obta ined.