Influence of resonant magnetic perturbations on plasma edge turbulence

This work reports alterations on plasma-edge equilibrium profiles and on edge turbulence, and anomalous transport induced by resonant perturbing magnetic fields in the TBR (Brazilian Tokamak) tokamak [J. Fusion Energy 12, 295 (1993)]. Thus, these perturbations have reduced the equilibrium parameters and the spectral power of the fluctuations and enhanced their phase velocity. They have also reduced the particle flux at the plasma edge. All these electrostatic edge parameters have been computed by taking into account temperature fluctuation corrections. Although the perturbation slightly affected just the linear correlation between electrostatic fluctuations, its bispectral analysis shows a reduction of the quadratic mode coupling. Furthermore, the energy transferred between different spectral components, with and without the magnetic perturbation, did not have the same direction for all fluctuations. Finally, the normal probability distribution functions of the fluctuations show significant non-Gaussian features, although the fluctuating potential distribution became near Gaussian with the magnetic perturbation.