Dynamics of Transport Barriers and ELM-Like Behaviour in Electrostatic Turbulence

摘要

The self-consistent development of transport barriers is investigated analytically and numerically in flux driven interchange turbulence. Numerical simulations show the turbulence leading to a homogenization of Lagrangian invariants by mixing, resulting in quasi-steady pressure profiles predicted by turbulent equipartition. Below a critical aspect ratio α = L_y/L_x ≈ 3.8, which is related to the rotational transform, large scale poloidal flows develop. They quench the turbulence, constitute transport barriers for the turbulent fluxes, but are intermittently disrupted by strong bursts in the transport, which may be related to the strong Edge Localized Modes (ELM) observed in toroidal devices.