On the Turbulent Behavior of a Magnetically Confined Plasma Near the X-Point

TL;DR

This paper models turbulence near the X-point in a Tokamak, revealing that enstrophy cascades dominate the turbulent behavior, with analysis linking plasma turbulence to fluid dynamics principles.

Contribution

It introduces a reduced two-dimensional model for plasma turbulence near the X-point, connecting it to the incompressible Navier-Stokes equation and highlighting enstrophy cascade dominance.

Findings

Turbulence near the X-point is dominated by enstrophy cascade.

The model maps plasma turbulence to fluid dynamics, enabling analytical and numerical analysis.

Turbulence behavior aligns with typical Tokamak operation conditions.

Abstract

We construct a model for the turbulence near the X-point of a Tokamak device and, under suitable assumptions, we arrive to a closed equation for the electric field potential fluctuations. The analytical and numerical analysis is focused on a reduced two-dimensional formulation of the dynamics, which allows a direct mapping to the incompressible Navier-Stokes equation. The main merit of this study is to outline how the turbulence near the X-point, in correspondence to typical operation conditions of medium and large size Tokamaks, is dominated by the enstrophy cascade from large to smaller spatial scales.