Geodesic acoustic modes excited by finite beta drift waves

Nikhil Kumar Chakrabarti, P.N. Guzdar, R.G. Kleva, Volker Naulin, Jens Juul Rasmussen, P.K Kaw

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    Abstract

    Presented in this paper is a mode-coupling analysis for the nonlinear excitation of the geodesic acoustic modes (GAMs) in tokamak plasmas by finite beta drift waves. The finite beta effects give rise to a strong stabilizing influence on the parametric excitation process. The dominant finite beta effect is the combination of the Maxwell stress, which has a tendency to cancel the primary drive from the Reynolds stress, and the finite beta modification of the drift waves. The zonal magnetic field is also excited at the GAM frequency. However, it does not contribute to the overall stability of the three-wave process for parameters of relevance to the edge region of tokamaks.
    Original languageEnglish
    JournalPhysics of Plasmas
    Volume15
    Issue number11
    Pages (from-to)112310
    ISSN1070-664X
    DOIs
    Publication statusPublished - 2008

    Bibliographical note

    Copyright (2008) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.

    Keywords

    • EXCITATION
    • ZONAL FLOWS
    • EXPLANATION
    • N=0 CHIRPING MODE
    • ALFVEN TURBULENCE
    • TOKAMAK
    • PLASMAS

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