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Statistical theory of plasma turbulence

Kim, E. and Anderson, J. (2009) Statistical theory of plasma turbulence. Plasma and Fusion Research, 4. Art no. 030. ISSN 1880-6821

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Abstract

We present a statistical theory of intermittency in plasma turbulence based on short-lived coherent structures (instantons). In general, the probability density functions (PDFs) of the flux R are shown to have an exponential scaling P(R) ∝ exp (-cRs ) in the tails. In ion-temperature-gradient turbulence, the exponent takes the value s = 3/2 for momentum flux and s = 3 for zonal flow formation. The value of s follows from the order of the highest nonlinear interaction term and the moments for which the PDFs are computed. The constant c depends on the spatial profile of the coherent structure and other physical parameters in the model. Our theory provides a powerful mechanism for ubiquitous exponential scalings of PDFs, often observed in various tokamaks. Implications of the results, in particular, on structure formation are further discussed.

Item Type: Article
Copyright, Publisher and Additional Information: © 2009 the Japan Society of Plasma Science and Nuclear Fusion Research. Reproduced in accordance with the publisher's self-archiving policy.
Keywords: turbulence; structure; shear flow; confinement; probability density function (PDF)
Institution: The University of Sheffield
Academic Units: The University of Sheffield > Faculty of Science (Sheffield) > School of Mathematics and Statistics (Sheffield)
Depositing User: Mrs Megan Hobbs
Date Deposited: 29 Mar 2010 12:01
Last Modified: 08 Jun 2014 08:49
Published Version: http://dx.doi.org/10.1585/pfr.4.030
Status: Published
Publisher: the Japan Society of Plasma Science and Nuclear Fusion Research
Identification Number: 10.1585/pfr.4.030
URI: http://eprints.whiterose.ac.uk/id/eprint/10501

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