Simulations Campaign of the Turbulent Diffusion at Tokamaks Edges

TL;DR

This paper uses a simplified 2D model based on reduced Braginskii equations to study turbulent diffusion and blob dynamics at tokamak edges, highlighting the roles of magnetic shear and plasma profiles.

Contribution

It introduces a numerical simulation approach combining Eulerian and Lagrangian analyses to explore turbulent transport in tokamak edge regions.

Findings

Magnetic shear and plasma profiles significantly influence transport properties.

Lagrangian tracers reveal diffusive transients at scales larger than blobs.

The model successfully describes blob formation and evolution in the scrape-off layer.

Abstract

The understanding of cross-field transport is crucial in order to optimize the properties of magnetic confinement in modern fusion devices. In this work, a two-dimensional, simplified model is used to study the turbulent dynamics in the region of the scrape-off layer. We show how the numerical model, based on the reduced Braginskii equations, is able to describe the formation and the evolution over time of blobs structures. We study these complex dynamics by using both classical Eulerian analysis and the Lagrangian approach, by varying the ambient conditions of the plasma. We have found that both the magnetic shear and the plasma profiles are crucial for the properties of the transport. By following Lagrangian tracers, we observed diffusive transients for the radial transport, at lengthscales larger than the typical blob size. This work is relevant for the comprehension of the turbulent transport at the edges of tokamak devices.