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Bibliographic Details
Main Authors: Scarivaglione, Luisa, Servidio, Sergio
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2505.03029
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Table of Contents:
  • Understanding turbulence via simplified fluid models is crucial for optimizing magnetic confinement in tokamak devices. In this work, we propose a novel high-order turbulence law that describes the turbulent cascade at the edges of fusion plasmas, namely valid within the Scrape-off Layer (SOL), in the framework of the Braginskii fluid model. Using the Yaglom-Monin approach, we derive an exact relation characterizing density fluctuations in these strongly magnetized systems. We obtain a third-order von Kármán-Howarth equation in increment form for the case of electrostatic Braginskii model, applied to a decaying turbulence regime. The new Yaglom-Braginskii law is validated through direct numerical simulations within a reduced (two-dimensional) model. Our analysis reveals that the plasma dynamics obey the cross-scale balance, exhibiting a well-defined inertial range of turbulence. This third-order law can provide an accurate measure of the cascade rate of density fluctuations in the scrape-off layer of laboratory plasmas.