Ponderomotive effects of a high-power EC wave upon perpendicular injection in a tokamak

The effect that the injection of a high-power electron cyclotron (EC) wave has on the dynamics of a tokamak plasma through its ponderomotive force is studied. A plasma rotation mechanism is analyzed, produced by the EC wave propagating perpendicular to the magnetic field, exhibiting its effect on the charged particles directly. It is shown that a particle flow in the poloidal direction is created, consistent with the action of a ponderomotive force associated with the wave, which in presence of a collisional force gives rise to a radial velocity. Under the influence of the in-out asymmetry of the tokamak the plasma spins up in the poloidal direction. Additional to this, there is also a field-aligned motion resulting from the decreasing wave amplitude, which is seen from the particle trajectories. For electrons, this motion would give rise to a parallel current, thus providing an alternative mechanism for driving current non inductively.