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Noble internal transport barriers and radial subdiffusion of toroidal magnetic lines

J. H. Misguich·J. D. Reuss·D. Constantinecu·Gy. Steinbrecher·M. Vlad·F. Spineanu·B. Weyssow·R. Balescu
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Abstract

Single trajectories of magnetic line motion indicate the persistence of a central protected plasma core, surrounded by a chaotic shell enclosed in a double-sided transport barrier : the latter is identified as being composed of two Cantori located on two successive "most-noble" numbers values of the perturbed safety factor, and forming an internal transport barrier (ITB). Magnetic lines which succeed to escape across this barrier begin to wander in a wide chaotic sea extending up to a very robust barrier (as long as L<1) which is identified mathematically as a robust KAM surface at the plasma edge. In this case the motion is shown to be intermittent, with long stages of pseudo-trapping in the chaotic shell, or of sticking around island remnants, as expected for a continuous time random walk.

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J. H. Misguich, J. D. Reuss, D. Constantinecu, Gy. Steinbrecher, M. Vlad, F. Spineanu, B. Weyssow, R. Balescu. 2002-05-31. Noble internal transport barriers and radial subdiffusion of toroidal magnetic lines. https://doi.org/10.1051/anphys%3A2004001

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