Effective fluid model of turbulent dynamics and transport in tokamak core plasmas

Abstract

A relatively simple dynamic model of low-frequency plasma convection is proposed to simulate turbulent cross-field transport in the tokamak core. The model is based on a special set of nonlinear weakly dissipative adiabatically reduced MHD-like equations, which self-consistently describe both turbulent plasma fluctuations and the resulting nondiffusive transport. Transient regimes with a fast turn on, turn off, and spatial redistribution of electron-cyclotron heating, as well as regimes with sawtooth oscillations were simulated numerically at time intervals exceeding the plasma energy confinement time. The results obtained demonstrate fast nonlocal responses of the resulting transport processes to the fast changes in external conditions and are in reasonable agreement with experiments in various tokamaks.