The image charge effects on plasma waves in the presence of neutral dust grains (original) (raw)

The effects of image charge on waves in dusty plasma

2004

A quantitative analysis of the image charge effects in dusty plasmas is presented. It is emphasized that the electrostatic interaction caused by the induced charge on grains can play an important role in dusty plasmas even in the case when in the equilibrium dust grains are not charged. As an example, the behavior of the ion electrostatic perturbations propagating in a plasma containing static and neutral (i.e., uncharged) dust grains is examined. A dispersion equation describing a dispersive and always unstable ion wave is obtained. Both the wave dispersion and the instability are a direct consequence of the image charge effect.

Electrostatic waves in a Maxwellian dusty plasma with variable charge on dust particles

Brazilian Journal of Physics, 2006

A kinetic formulation developed to analyze wave propagation in dusty plasmas, which takes into account the variation of the charge of the dust particles due to inelastic collisions with electrons and ions, is utilized to study the propagation and damping of electrostatic waves with wave number exactly parallel to the external magnetic field and Maxwellian distributions for the electrons and ions in the equilibrium. It is shown that, due to the presence of the dust, the damping of Langmuir waves in the region of large wavelengths is increased as compared to conventional Landau damping. Langmuir waves in the occurrence of collisional charging of dust particles also feature weak damping for small wavelengths, which vanishes if the effect of collisional charging of the dust particles is neglected in the dispersion relation. It is also shown that the damping of ion-acoustic waves is modified by the presence of the dust, and that some damping effect due to the dust particles remains even if the effect of collisional charging of dust particles is neglected in the dispersion relation.

Effects of dust charge variation on electrostatic waves in dusty plasmas with temperature anisotropy

Brazilian Journal of Physics, 2009

We utilize a kinetic approach to the problem of wave propagation in dusty plasmas, taking into account the variation of the charge of the dust particles due to inelastic collisions with electrons and ions. The components of the dielectric tensor are written in terms of a finite and an infinite series, containing all effects of harmonics and Larmor radius. The formulation is quite general and valid for the whole range of frequencies above the plasma frequency of the dust particles, which are assumed motionless. The formulation is employed to the study of electrostatic waves propagating along the direction of the ambient magnetic field, in the case for which ions and electrons are described by bi-Maxwellian distributions. The results obtained in a numerical analysis corroborate previous analysis, about the important role played by the dust charge variation, particularly on the imaginary part of the dispersion relation, and about the very minor role played in the case of electrostatic waves by some additional terms appearing in the components of the dielectric tensor, which are entirely due to the occurrence of the dust charge variation.

Effects of charge dispersion in dusty plasmas

Journal of Plasma Physics, 1995

We investigate the charge-dispersive effects on a sheath of monosized dust particles in equilibrium. This is done through describing the dust particles by using equations in (x, v) space (kinetic space) that include terms originating from the charge distribution of the dust particles. The charge-dispersive terms are assumed to be completely determined by the local charging processes. We find that the effects due to these terms are opposed by the ordinary gradient terms in the current equation in kinetic space, and they are therefore smaller than first expected. We also identify kinetic effects that are not included in the usual expression for the dust charge in hydrodynamic space.

Oscillations in a Dusty Plasma Medium

2002

Novel properties introduced by charged particulates in a plasma medium and how they influence excitation and propagation of waves are discussed. Such a medium, commonly known as dusty plasma, is generated in the near Earth environment by dust and other debris of meteoric origin and exhausts and effluents from space platforms. A novel feature of dusty plasma is that the charge to mass ratio can become a dynamical variable and represent an additional degree of freedom unavailable to a classical plasma. Charged dust particles in a plasma introduce unique potential structures and significantly alter the short and long range forces which can affect the short and long range ordering of the dust grains.

Electrostatic interaction in dusty plasma

Physical Review E, 2002

Two modifications of the standard description of electrostatic interaction in a dusty plasma are emphasized. First, the Coulomb-type potential profile is not applicable at very short distances around a dust grain, due to the polarization of the charge on the grain, i.e., the image charge effect, and, second, at larger distances, the standard Debye-Hückel potential screening is modified due to nonlinear corrections in the expanded Boltzmann distribution for plasma particles.

Dust acoustic and drift waves in a non-Maxwellian dusty plasma with dust charge fluctuation

Journal of Plasma Physics, 2015

The properties of dust acoustic and drift waves are investigated in a charge varying magnetized dusty plasma. The plasma is composed of non-thermal electrons and ions with dynamic dust particles. The mathematical expression which describes the dust charge fluctuation is obtained using${\it\kappa}$-distribution for both the electrons and ions. A dispersion relation is derived and analysed numerically by choosing space plasma parameters. It is found that the inclusion of variable dust charge along with the non-thermal effects of electrons and ions significantly affect linear/nonlinear properties of the dust acoustic and dust drift waves. The effects of different physical parameters including spectral index (${\it\kappa}$), dust charge number ($Z_{d}$), electron density ($n_{e}$) and ion temperature ($T_{i}$) on the wave dispersion and instability are presented. It is found that the presence of the non-thermal electron and ion populations reduce the growth rate of the instability which...

High-Frequency Surface Waves in Dust-Containing Plasmas

The comprehensive studies of collective processes in bounded plasmas are stimulated by significant success achieved in recent years by new low-temperature plasma technologies . Many low-temperature technological plasma are contaminated by highly charged impurities or dust. The presence of the latter is naturally caused by erosion of the processed surfaces or polymerization in the gaseous phase . Therefore, the modelling of dust-contaminated gas discharges is actual. The massive (in comparison with the plasma ions) particles significantly affect the charge balance in plasmas, accumulating the considerable amount of negative charge and producing the specific dust-charge fluctuations . The problem of influence of dust on dispersion characteristics of plasma waves needs detailed examination, and there are many important factors significantly affecting the process. Specifically, we would like to emphazise the open character of plasma-dust system demanding rigorous account of collision mechanisms specific to dust-contaminated plasmas, especially those leading to plasma recombination ("sinks"). The account of the latter is natural for open systems like most of gas discharges.