A mixed SOC-turbulence model for nonlocal transport and Lévy-fractional Fokker–Planck equation |
| |
Authors: | Alexander V Milovanov Jens Juul Rasmussen |
| |
Institution: | 1. ENEA National Laboratory, Centro Ricerche Frascati, I-00044 Frascati, Rome, Italy;2. Department of Space Plasma Physics, Space Research Institute, Russian Academy of Sciences, 117997 Moscow, Russia;3. Physics Department, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark |
| |
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. |
| |
Keywords: | Random processes and Lé vy flights Self-organized criticality Fractional kinetics Drift-wave turbulence |
本文献已被 ScienceDirect 等数据库收录! |
|