596 research outputs found
Instability of Shear Waves in an Inhomogeneous Strongly Coupled Dusty Plasma
It is demonstrated that low frequency shear modes in a strongly coupled,
inhomogeneous, dusty plasma can grow on account of an instability involving the
dynamical charge fluctuations of the dust grains. The instability is driven by
the gradient of the equilibrium dust charge density and is associated with the
finite charging time of the dust grains. The present calculations, carried out
in the generalized hydrodynamic viscoelastic formalism, also bring out
important modifications in the threshold and growth rate of the instability due
to collective effects associated with coupling to the compressional mode.Comment: 9 pages with 2 figure
Experimental study of nonlinear dust acoustic solitary waves in a dusty plasma
The excitation and propagation of finite amplitude low frequency solitary
waves are investigated in an Argon plasma impregnated with kaolin dust
particles. A nonlinear longitudinal dust acoustic solitary wave is excited by
pulse modulating the discharge voltage with a negative potential. It is found
that the velocity of the solitary wave increases and the width decreases with
the increase of the modulating voltage, but the product of the solitary wave
amplitude and the square of the width remains nearly constant. The experimental
findings are compared with analytic soliton solutions of a model Kortweg-de
Vries equation.Comment: The manuscripts includes six figure
Driven transverse shear waves in a strongly coupled dusty plasma
The linear dispersion properties of transverse shear waves in a strongly
coupled dusty plasma are experimentally studied by exciting them in a
controlled manner with a variable frequency external source. The dusty plasma
is maintained in the strongly coupled fluid regime with (1 < Gamma << Gamma_c)
where Gamma is the Coulomb coupling parameter and Gamma_c is the
crystallization limit. A dispersion relation for the transverse waves is
experimentally obtained over a frequency range of 0.1 Hz to 2 Hz and found to
show good agreement with viscoelastic theoretical results.Comment: The manuscripts contains five pages and 6 figure
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