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Abstract
XVIII Sympozjum PTZE, Zamość 2008
PLASMA WAVE MODIFICATIONS
IN THE PRESENCE OF DUST
Barbara Atamaniuk (1) , Andrzej J. Turski (1) Alexander S. Volokitin (2)
(1) Institute of Fundamental Technological Research, PAS,
Warsaw, Poland
(2) Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation,
Moscow, Russia
The study of waves and instabilities has always been important in plasma physics. Physics of
dusty plasmas is recently studied intensively because of its importance for a number of
applications in space plasmas, earth’s environment as well as in the laboratory. Dusty plasma
consists of charged dust grain embedded in ambient plasma. Depending on their concentrations,
one has isolated screened dust grains (dust-in-plasma) or real collective dusty plasmas where the
charged dust participated in Debye screening. We shall mainly discuss space dusty plasmas
although many of the conclusions are valid for the laboratory plasmas as well. We call ''dusty
plasma'' when number of grains in Debye sphere is greater than one and ''dust in a plasma'' when
number density of grains is less than one.
The presence of dust in astrophysical environments has been known for a long time, from
different types of remote observations, as for the dust around and between stars. There are
beautiful examples of dust, like the molecular clouds seen in the Orion, Coalsack, Horsehead and
Eagle nebulae. We observe these because of the attenuation and extinction of the light coming
from more distant stars.
There is also plenty of dust in the heliosphere, associated with planetary rings, cometary comae
and tails, meteoric impacts...
The simplest way, theoretically, dust effects have been investigated by extending the usual two
component treatment of plasmas with the addition of third component – the dust. In dusty plasma,
a large fraction of the negative charge ids bound to the particles. The depletion of electrons by
absorption on the dust particle affects all kinds of plasma wave mode.
Due to the unusually low charge-to-mass ratio of the dust, the characteristic dust frequencies are
well below those typical for typical plasma. Small characteristic frequencies will give rise to new
low-frequency eigenmodes of the combined plasma, clearly separated from the usual plasma
modes.
One striking aspect of these dust waves is that they can be imaged by video camera recording
scattered light.
In this presentation we make some review and we give some particular examples of waves in
dusty plasmas.
This research is supported by KBN grant 0TOOA01429
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