Spectral energy transfer and generation of turbulent structures in toroidal plasma

Abstract

The nonlinear energy cascades in turbulent spectra was analyzed using the spectral energy transfer and the amplitude correlation technique. It was shown that an inverse energy cascade of the spectral energy is responsible for the generation of the large scale coherent structures dominating turbulent spectra. The zonal flows present in these structures are also generated via the inverse cascade. The zonal flows are generated with the increased strength in the nonlinear energy transfer.