Gyrokinetic simulation of the toroidal rotation driven by the ambipolar radial electric field induced by stochastic magnetic perturbations in a tokamak plasma.

Gyrokinetic simulation of the toroidal rotation of plasma with a stochastic magnetic field perturbation is carried out. The simulation results suggest that the stochastic magnetic perturbation drives the plasma to toroidally rotate through the ambipolar radial electric field E r established on the timescale of electron transit time. It is found that this spontaneous flow driven on the timescale less than an ion–ion collision time is the parallel return flow of the E r × B drift. The ion–ion collisional effect further changes the parallel return flow to the toroidal rigid-body flow after a few ion–ion collision times. This simulation result is consistent with the toroidal rigid-body rotation observed in tokamak experiments with a stochastic layer induced by the externally applied resonant magnetic perturbation. [ABSTRACT FROM AUTHOR]