Particles In Dusty Plasma Research Articles

On Anomalous Dissipation in Plasma of Dusty Mercury’s Exosphere

The anomalous dissipation related to the effect of charging of dust particles that gives rise to new physical phenomena, effects, and mechanisms represents one of the main specific features of dusty plasma that makes it different from conventional plasma containing no charged dust particles. We analyze the process of anomalous dissipation in the context of description of the dynamics of dust particles in dusty plasma of the Mercury’s exosphere. An analytical description of oscillations of a dust particle above the surface of Mercury is presented. The frequency of charging of dust particles that characterizes the anomalous dissipation determines the damping of such oscillations. It is demonstrated that the anomalous dissipation is important for substantiation of the model of levitating dust particles that is used for description of dusty plasma above Mercury. The results of numerical simulations that justify the use of the discussed model are presented.

Degradation of the surface of melamine formaldehyde particle in dusty plasma in neon and krypton

A comprehensive decrease in the particle size and a change in the surface morphology, depending on an exposure time in plasma in krypton, have been experimentally established. The results of the size degradation and the surface modification are compared with the results obtained in a lighter inert gas. It is shown that, under similar experimental conditions, the degradation of particles in the heavy gas begins faster.

Degradation of the Surfaces of Melamine Formaldehyde Particles in Dusty Plasma in Neon and Krypton

Degradation of the Surfaces of Melamine Formaldehyde Particles in Dusty Plasma in Neon and Krypton

Separation of Particles in Dusty Plasma in Mixtures of Inert Gases

Separation of Particles in Dusty Plasma in Mixtures of Inert Gases

Modification and Mass Loss of Melamine Formaldehyde Particles in Dusty Plasma Formed in Heavy Noble Gas

Modification and Mass Loss of Melamine Formaldehyde Particles in Dusty Plasma Formed in Heavy Noble Gas

Generalized non-ideal treatment and growth rates analysis of drift waves instabilities in a collisions-free magnetized dusty plasma

Dust acoustic wave propagation in weak magnetized homogeneous dusty plasmas has been extensively and successfully studied by different authors. Here, it is analyzed the behavior of electrostatic drift waves of very low frequency, appearing as due to the motion of plasma particles across the static magnetic field and the inhomogeneity introduced by the distribution of the particles in the dusty plasma generating the well-known diamagnetic effect. To study this situation, the kinetic Vlasov model in plasmas will be used. However, these models tend to behave unstably driven by the quasi-equilibrium of the diamagnetic current arising by the heavier species of dusty plasma particles. While other authors have used a standard state equation, such as the Van der Waals one, here, a more accurate model has been chosen as the equation of Ree and Hoover, a state equation that can be considered as a new form of the state equation. Together with the multipole approximation of the dispersion function, Z53 [P. Martin et al., J. Math. Phys. 21, 280–283 (1980)] allows a new derivation to obtain the simplest form of the dispersion relation in the form of a polynomial with complex coefficients. This mathematical approach was realized successfully and allowed straightforward calculus of the growth rate due to the drift unstable mode. This problem has been extensively analyzed in this work, including the non-ideal effect of dusty plasmas. These unstable modes are well discriminated and plotted as a function of the density of the grains in dusty plasma and their radius. Temperature gradients and charge fluctuation have been ignored.

Some aspects of fluctuations dynamics of particles in dusty plasma

Dusty plasmas are formed when micrometre particles of solid matter are introduced into glow discharge plasma. In the present research work, we investigated the fluctuation dynamics of the particles using the dynamic light scattering (DLS) technique and particle tracking with high-speed imaging technique. The DLS technique gives light intensity fluctuation which is analysed by fractal tools namely wavelet scalogram to give the Hurst parameter, “H” being associated with the fractional Brownian motion. The structural phases of particles are analysed using the pair correlation function. Particle trajectory analysis determines the transport characteristics of the charged dust particles. The scaling behaviour of the mean squared displacement (MSD) is investigated for different pressures. Results from both the DLS and MSD analysis are discussed regarding different transport mechanisms based on the fractional Brownian motion as the transport model. This study also highlighted the use of fractal analysis as a powerful tool for investigating fluctuation dynamics in dusty plasmas.

Excitation of Gould–Trivelpiece mode by streaming particles in dusty plasma-reinvestigated

Propagation of waves through a dusty plasma is of great importance, and its details are investigated. Recently, excitation of Gould–Trivelpiece mode by streaming particles in dusty plasma has been discussed by Kaur et al. (2019) [6]. We have looked into that work and our observations are presented here. Several discrepancies have been found in the work, and therefore, the results published in that paper may not be reliable.

About the mechanism of modification of melamine formaldehyde particles in dusty plasmas

The article presents the previously obtained results of the modification of spherical microparticles of melamine-formaldehyde injected as a dust component of complex plasma formed in stratified glow discharge in neon. Particular attention is paid to changing the particle size depending on the residence time in the plasma. A mechanism is proposed for heating particles by ion flow sustaining a stable charge of their surface. Calculations of the heat balance are presented, confirming the results obtained in the experiment.

Particle charge fluctuation and its consequences on aerosol dynamics in dusty plasmas: from continuous to discrete statistical models

In this work we investigated different approaches and models used for the estimation of the charge fluctuation of solid particles in dusty plasmas. We compared the charge distributions inferred from these models and analyzed the consequences in terms of coagulation kinetics and particle size distributions. We especially showed that taking explicitly into account the discrete nature of the charging process along with the enhancement of ion flux due to ion-neutral elastic collisions result in significantly larger values for the fractions of neutral and positively charged particles, which affects the coagulation kinetics and the predicted values of particle density. We also showed, by comparing sectional and modal approaches, that the typical size distributions obtained in the studied plasmas may be well described using a bimodal distribution with a single size nucleation mode and a Gaussian large size mode. Such a possibility enables a great simplification of the aerosol dynamic description and open up an interesting perspective as far as multidimensionnal self consistent modeling of dusty plasmas is concerned.

Excitation of Gould–Trivelpiece mode by streaming particles in dusty plasma

AbstractIn this paper, we study the excitation of Gould–Trivelpiece (TG) waves by streaming ions in dusty plasma and derive the dispersion relation of the excited waves using first-order perturbation theory. The motion of charged particles is controlled by electromagnetic fields in plasma. The energy transfer processes which occur in this collisionless plasma are believed to be based on wave–particle interactions. We have found that the TG waves may be generated in a streaming ion plasma via Cerenkov interaction, and the ions may be accelerated by TG waves via cyclotron interaction, which enable energy and momentum transfer. The variation in the growth rate of TG wave with dust grain size and relative density of negatively charged dust grains is also studied. The dust can cause an unstable TG mode to be stable in Doppler resonance, and can induce an instability in Cerenkov interaction.

The effect of magnetic field on plasma particles in dusty plasma

In this work, we present the investigation of the formation features and internal structure of dust clouds created in plasma of glow discharge in the external magnetic field corresponding to a range of moderate and strong fields, at which the ion component is magnetized. The analysis of the plasma magnetization in the presence of dust components is carried out. We defined the values of magnetic induction at which the changes in dynamics of plasma particles in magnetic field in light inert gases are expected. The experimental setup was built in two versions. For the purpose of generating of magnetic field, the first setup was equipped with ordinary magnetic coils, and the second one included a superconducting solenoid. The discharge tubes, the main chambers where plasma was ignited and maintained in a glow discharge in lowered pressure, also have certain peculiarities, which we describe below. While using helium as a bulk gas, our study focused only on the dust trap in the region of narrowing discharge current. For neon, we used two traps: the striation trap and one just mentioned above placed in the narrowing of the discharge tube. As a result, the steady dust structures in a glow discharge under the magnetization of ions and electrons were obtained for the first time. Dust structures were rotated and tended to form a dust cluster and shell structure. A number of parameters of magnetization achieved in experiments were calculated.

Computer modeling and simulation of electrically charged nano/micro-particles interaction into aqueous solution by the Brownian dissipative dynamics of their atomic counterions ensemble

On the basis of free energy functional of charged ions and equation of diffusion of ions in self-consistent electric potential, a method of Brownian dissipative dynamics of ions near electrically charged colloidal micro/nano-particles in aqueous solution or dusty plasma particles in the air is proposed for investigation of ionic atmosphere structure near charged surfaces, and electric interparticle force is calculated.

Effect of dust particle on dusty plasma’s dispersion characteristic

In this paper, the effect of dust particle on dusty plasma’s dispersion characteristic is studied under two possible conditions. Firstly, based on the known complex refractive index formula, the dispersion ability of the real and imaginary parts are determined. Then, the dispersion ability of the dusty plasma under two different conditions is discussed, according to the neutral conditions between particles in dusty plasma. The research results show that: (1) The magnitude of dispersion ability decreases significantly with the incident electromagnetic wave’s angular frequency increases; (2) The value of the dispersion ability under condition 1 is much smaller than the dispersion ability under condition 2. Finally, it is pointed that the dispersion ability difference between dusty and common plasma can be mainly attributed to the dust particle, and the effect of dust particle radius and number density on the dispersion ability of dusty plasma is similar.

Slowing down of charged particles in dusty plasmas with power‐law kappa‐distributions

We study the slowing down of a particle beam passing through the dusty plasma with power‐law κ‐distributions. Three plasma components, electrons, ions, and dust particles, can have a different κ‐parameter. By using Fokker‐Planck theory, the deceleration factor and slowing down time are derived and expressed by a hyper‐geometric κ‐function. Numerically, we study the slowing down property of an electron beam in the κ‐distributed dusty plasma. We show that the slowing down in the plasma depends strongly on the κ‐parameters of plasma components, and dust particles play a dominant role in the deceleration effects. We also show dependence of the slowing down on mass and charge of a dust particle in the kappa‐distributed plasma.

Memory effects in the velocity relaxation process of the dust particle in dusty plasma

In this paper, by comparing the timescales associated with the velocity relaxation and correlation time of the random force due to dust charge fluctuations, memory effects in the velocity relaxation of an isolated dust particle exposed to the random force due to dust charge fluctuations are considered, and the velocity relaxation process of the dust particle is considered as a non-Markovian stochastic process. Considering memory effects in the velocity relaxation process of the dust particle yields a retarded friction force, which is introduced by a memory kernel in the fractional Langevin equation. The fluctuation-dissipation theorem for the dust grain is derived from this equation. The mean-square displacement and the velocity autocorrelation function of the dust particle are obtained, and their asymptotic behavior, the dust particle temperature due to charge fluctuations, and the diffusion coefficient are studied in the long-time limit. As an interesting feature, it is found that by considering memory effects in the velocity relaxation process of the dust particle, fluctuating force on the dust particle can cause an anomalous diffusion in a dusty plasma. In this case, the mean-square displacement of the dust grain increases slower than linearly with time, and the velocity autocorrelation function decays as a power-law instead of the exponential decay. Finally, in the Markov limit, these results are in good agreement with those obtained from previous works on the Markov (memoryless) process of the velocity relaxation.

Twisted dust acoustic waves in dusty plasmas

We examine linear dust acoustic waves (DAWs) in a dusty plasma with strongly correlated dust grains, and discuss possibility of a twisted DA vortex beam carrying orbital angular momentum (OAM). For our purposes, we use the Boltzmann distributed electron and ion density perturbations, the dust continuity and generalized viscoelastic dust momentum equations, and Poisson’s equation to obtain a dispersion relation for the modified DAWs. The effects of the polarization force, strong dust couplings, and dust charge fluctuations on the DAW spectrum are examined. Furthermore, we demonstrate that the DAW can propagate as a twisted vortex beam carrying OAM. A twisted DA vortex structure can trap and transport dust particles in dusty plasmas.

Optical and kinetic properties of the dusty plasma in radiofrequency discharge

Dependence of diffusion coefficient of dusty particles in dusty plasma was experimentally obtained. A proportional increase of diffusion of the dust particles with the increase of the discharge power was experimentally found. The pair correlation functions of dusty particles were also obtained from the experiments and the change of dust cloud structure with the increase of the discharge power was observed. The influence of the dust particles on the spectrum of plasma glow was investigated using spatial spectrometer. It was shown that upon introduction of dust particles into the plasma bulk the overall intensity of the plasma glow decreases.

Stochastic heating of dust particles in complex plasmas as an energetic instability of a harmonic oscillator with random frequency

The paper describes the occurrence of stochastic heating of dust particles in dusty plasmas as an energy instability due to the correlations between dust grain charge and electric field fluctuations. The possibility that the mean energy (“temperature”) of dust particles can grow in time has been found both from the self-consistent kinetic description of dusty plasmas taking into account charge fluctuations [U. de Angelis, A. V. Ivlev, V. N. Tsytovich, and G. E. Morfill, Phys. Plasmas 12(5), 052301 (2005)] and from a Fokker-Planck approach to systems with variable charge [A. V. Ivlev, S. K. Zhdanov, B. A. Klumov, and G. E. Morfill, Phys. Plasmas 12(9), 092104 (2005)]. Here, a different derivation is given by using the mathematical techniques of the so called multiplicative stochastic differential equations. Both cases of “fast” and “slow” fluctuations are discussed.

New Model of Dusty Plasma Particles Interaction

AbstractThe main goal of this report is to obtain the macropotentials of dusty plasma particles interactions which account for the collective events in the medium and, then, to analyze their dependence on plasma parameters. It is shown that the attraction between conductive dust grains turns possible due to the polarization phenomenon (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)