The Radial Propagation of Heat in Strongly Driven Non-Equilibrium Fusion Plasmas

Entropy

Luis García¹  Javier Nicolau¹  Benjamin Carreras¹  Boudewijn van Milligen² 

[1] Departamento de Física, Universidad Carlos III de Madrid, Av. de la Universidad 30, 28911 Leganés, Madrid, Spain;Laboratorio Nacional de Fusión, CIEMAT, Av. Complutense 40, 28040 Madrid, Spain;

关键词: magnetic confinement fusion;    turbulence;    heat transport;   

DOI  :  10.3390/e21020148

来源: DOAJ

【 摘 要 】

Heat transport is studied in strongly heated fusion plasmas, far from thermodynamic equilibrium. The radial propagation of perturbations is studied using a technique based on the transfer entropy. Three different magnetic confinement devices are studied, and similar results are obtained. “Minor transport barriers„ are detected that tend to form near rational magnetic surfaces, thought to be associated with zonal flows. Occasionally, heat transport “jumps„ over these barriers, and this “jumping„ behavior seems to increase in intensity when the heating power is raised, suggesting an explanation for the ubiquitous phenomenon of “power degradation„ observed in magnetically confined plasmas. Reinterpreting the analysis results in terms of a continuous time random walk, “fast„ and “slow„ transport channels can be discerned. The cited results can partially be understood in the framework of a resistive Magneto-HydroDynamic model. The picture that emerges shows that plasma self-organization and competing transport mechanisms are essential ingredients for a fuller understanding of heat transport in fusion plasmas.

【 授权许可】

Unknown