Synergy of turbulent and neoclassical transport through poloidal convective cells

The role of poloidal convective cells-i.e. low frequency axisymmetric modes of the electric potential-on transport processes is studied with the full-F gyrokinetic code GYSELA. In order to understand the impact of convective cells, we apply a numerical filter to convective cells and compare the simulation results with and without the filter. The energy flux driven by the magnetic drifts (due to the curvature of the magnetic field lines and to the gradient of the magnetic field intensity del B) Q(i)(D) turns out to be reduced by a factor of about 2 once the numerical filter is applied. A careful analysis reveals that the frequency spectrum of the convective cells is well-correlated with that of the turbulent Reynolds stress tensor, giving credit to their turbulence driven origin. The impact of convective cells on Q(i)(D) can be interpreted as a synergy between turbulence and neoclassical dynamics.