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ABSTRACT
Flute Instability
is of great importance in magnetically confined plasmas. It appears
in applications such as fusion energy and space physics. Our aim is
to develop a general analysis of nonlinear dynamics of drift-flute waves,
applicable to arbitrary plasma beta and arbitrary spatial scales in
comparison with the ion Larmor radius. This study is of interest for
fundamental plasma theory as well as for the interpretation of Z-pinch
and laboratory astrophysics experiments. Description of low-frequency
waves and in particular drift flute waves in a high beta plasma, generally
speaking, require a kinetic approach, based on the Vlasov-Maxwell set
of equations. In the present work we show that the alternative two-fluid
description can adequately describe the ion perturbations with arbitrary
ratio of the characteristic spatial scales to the ion Larmor radius
in so-called Pade approximation. For this purpose reduced two-fluid
hydrodynamic equations, which describe nonlinear dynamics of the flute
waves with, arbitrary spatial scales and arbitrary plasma beta are derived.
The linear dispersion relation of the flute waves and the Rayleigh-Taylor
instability are analyzed. A general nonlinear dispersion relation, which
describes generation of large-scale zonal structures by the flute waves,
is presented and analyzed.
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