Original scientific paper
Linear waves in a self-gravitating dusty plasma with dust charge fluctuation
K. K. Mondal
; Department of Physics, Raja Peary Mohan College, Uttarpara, Hooghly, West Bengal India, Pin-712258
Abstract
In astrophysical environments, dynamics of large bodies such as planets, stars and satellites is solely governed by gravitational force, whereas electromagnetic force is the only force effective in controlling the dynamics of electrons, ions. It is very interesting to note that for the micron and submicron size dust grains these two forces become comparable, i.e. Gm2 d/q2 d ≈ O(1) and the interplay between the gravitational and the electrostatic forces in the dynamics of such grains leads to various novel phenomena in the terrestrial and solar environment. Our motivation is to study linear waves excited in a dusty plasma due to self gravity. The constituents of our plasma system are electrons, ions, and micron- and submicron-sized dust grains. We consider this dusty plasma to be infinite, homogeneous with spatially uniform densities of the species. The ratio G md2/q d2 is very small for the electrons and ions, and so the effects of self gravity for these species may be neglected. Moreover, we have taken into account the ion-dynamics together with the dust-dynamics and charge fluctuation of the dust grains. Then we have derived a dispersion law associated with the analysis of the linear gravitational instability of the waves. In our analysis, we disregard the zero-order gravitational field and so Poisson's equation for the gravitational potential, ψ, has to be modified. The dispersion law has been analysed in detail and various cases are discussed.
Keywords
dusty plasma; gravitational and electrostatic force; linear waves; charge fluctuation of the dust grains; dispersion law
Hrčak ID:
304458
URI
Publication date:
1.3.2007.
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