Effective model of turbulent plasma convection in the tokamak core

It has been shown that low-frequency turbulent convection self-consistently developed in the tokamak core can be effectively described in the framework of a relatively simple model based on a closed system of weakly dissipative reduced magnetohydrodynamic-type equations. The results of the numerical simulation of transient regimes, including regimes with sawtooth oscillations and with a fast spatial redistribution of the auxiliary heating power, are reported. The results indicate that the response of the resulting transport processes to fast changes in the external conditions is nondiffusive and nonlocal and are in reasonable agreement with experiments at various tokamaks.