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arXiv · 1403.5896

A mixed SOC-turbulence model for nonlocal transport and Levy-fractional Fokker-Planck equation

Alexander V. Milovanov·Jens Juul Rasmussen
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Abstract

The phenomena of nonlocal transport in magnetically confined plasma are theoretically analyzed. A hybrid model is proposed, which brings together the notion of inverse energy cascade, typical of drift-wave- and two-dimensional fluid turbulence, and the ideas of avalanching behavior, associable with self-organized critical (SOC) behavior. Using statistical arguments, it is shown that an amplification mechanism is needed to introduce nonlocality into dynamics. We obtain a consistent derivation of nonlocal Fokker-Planck equation with space-fractional derivatives from a stochastic Markov process with the transition probabilities defined in reciprocal space. The hybrid model observes the Sparre Andersen universality and defines a new universality class of SOC.

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Alexander V. Milovanov, Jens Juul Rasmussen. 2014-03-24. A mixed SOC-turbulence model for nonlocal transport and Levy-fractional Fokker-Planck equation. https://doi.org/10.1016/j.physleta.2014.03.047

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