Ideal And Resistive Magnetohydrodynamic Modes

    Authors

    B. K. Shivamoggi

    Comments

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    Abbreviated Journal Title

    Int. J. Theor. Phys.

    Keywords

    Hydromagnetic Surface-Waves; Resonance-Absorption; Alfven Waves; Spectrum; Plasma; MHD; Dissipation; Decay; Physics, Multidisciplinary

    Abstract

    This paper gives a further discussion of the analytical properties of both discrete and continuous Alfven wave spectra in an incompressible as well as compressible plasma. Although the continuous MHD modes produced by a well-behaved initial perturbation decay according to a power law, some singular solutions exist and are found to behave differently. In particular, it is possible to exhibit the existence of a new continuous mode which decays exponentially, and not as an inverse power of time, and this exponential damping is not the consequence of a continuous variation of the magnetic field. Even the set of discrete magnetohydrodynamic modes is shown to be empty unless certain conditions are satisfied. Next, we consider resistive modes and give explicit solutions for them which are valid in the neighborhood of the Alfven resonance layer and discuss their implications for plasma heating schemes. Finally, we study discrete and continuous Alfven wave spectra in a compressible plasma and discuss how they behave differently from those in an incompressible plasma. In particular, we show that though compressibility of the plasma is responsible for the slow mode continuum, strong compressibility will eliminate it. The discrete modes in a compressible plasma undergo an exponential damping even in an ideal plasma if the compressibility is strong.

    Journal Title

    International Journal of Theoretical Physics

    Volume

    31

    Issue/Number

    12

    Publication Date

    1-1-1992

    Document Type

    Article

    Language

    English

    First Page

    2121

    Last Page

    2141

    WOS Identifier

    WOS:A1992JX00700010

    ISSN

    0020-7748

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