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. © 2014 Elsevier B.V.
Titolo: | A mixed SOC-turbulence model for nonlocal transport and Lévy-fractional Fokker-Planck equation |
Data di pubblicazione: | 2014 |
Rivista: | |
Handle: | http://hdl.handle.net/20.500.12079/2838 |
Appare nelle tipologie: | 1.1 Articolo in rivista |