Showing papers on "Dusty plasma published in 2013"

Bifurcations of dust ion acoustic travelling waves in a magnetized dusty plasma with a q-nonextensive electron velocity distribution

Abstract: Nonlinear ion acoustic waves in the magnetized dusty plasma in the presence of superthermal electron have been studied. We have used the reductive perturbation method to derive a Kadomtsev-Petviashili equation for dust ion acoustic waves in a magnetized dusty plasma with q-nonextensive velocity distributed electrons. By applying the bifurcation theory of planar dynamical systems to this equation, the existence of solitary wave solutions and periodic travelling wave solutions is proved. Two exact solutions of the above waves are obtained.

Dust-ion-acoustic supersolitons in dusty plasmas with nonthermal electrons.

Abstract: Supersolitons are a recent addition to the literature on large-amplitude solitary waves in multispecies plasmas. They are distinguished from the usual solitons by their associated electric field profiles which are inherently distinct from traditional bipolar structures. In this paper, dust-ion-acoustic modes in a dusty plasma with stationary negative dust, cold fluid protons, and nonthermal electrons are investigated through a Sagdeev pseudopotential approach to see where supersolitons fit between ranges of ordinary solitons and double layers, as supersolitons always have finite amplitudes. They therefore cannot be described by reductive perturbation treatments, which rely on a weak amplitude assumption. A systematic methodology and discussion is given to distinguish the existence domains in solitary wave speed and amplitude for the different solitons, supersolitons and double layers, in terms of compositional parameters for the plasma model under consideration.

Dusty plasma at the surface of the moon

Abstract: A theoretical model that provides a self-consistent description of the concentrations of photoelectrons and dust particles located over the illuminated part of the lunar surface is presented. The model takes account of the observation point location and the effects of production of photoelectrons at the surfaces of the Moon and dust particles, the dynamics of dust particles in the electric and gravitational fields, and the charging of dust particles through their interaction with the solar radiation photons, the solar wind electrons and ions, photoelectrons, etc. An expression that describes the distribution of photoelectrons over the illuminated part of the lunar surface is obtained. The size and elevation distributions of the charged dust particles located over the illuminated part of the lunar surface are calculated for different angles between the local normal and the direction to the Sun. It is shown that no substantial restrictions are imposed on the choice of the landing site for future lunar spacecraft missions aimed at studying the near-surface dust on the Moon.

Simulating the dynamics of complex plasmas

Abstract: Complex plasmas are low-temperature plasmas that contain micrometer-size particles in addition to the neutral gas particles and the ions and electrons that make up the plasma. The microparticles interact strongly and display a wealth of collective effects. Here we report on linked numerical simulations that reproduce many of the experimental results of complex plasmas. We model a capacitively coupled plasma with a fluid code written for the commercial package comsol. The output of this model is used to calculate forces on microparticles. The microparticles are modeled using the molecular dynamics package lammps, which we extended to include the forces from the plasma. Using this method, we are able to reproduce void formation, the separation of particles of different sizes into layers, lane formation, vortex formation, and other effects.

Dusty plasma effects in comets: expectations for rosetta

Abstract: [1] Despite their small masses, comets have played an extraordinary role in enhancing our understanding of cosmic physics. It was the calculation of comet Halley's orbit and the successful prediction of its return in 1758 that firmly established the correctness of Newton's law of universal gravitation. It was the morphology of the dusty tails of comets that provided the earliest information of the nature of the interaction of solar electromagnetic radiation with dust, and it was the orientation and structure of the plasma tails of comets that led to the discovery of the solar wind. More recently, the role of the changing dusty plasma environments of comets as natural space laboratories for the study of dust-plasma interactions, and their physical and dynamical consequences, has been recognized. The forthcoming Rosetta-Philae rendezvous and lander mission will provide a unique opportunity to revisit the entire range of earlier observations of dusty plasma phenomena in a single comet, as it moves around the Sun. In this topical review, motivated by the Rosetta mission, we discuss the varying modes of interaction of the comet as it approaches the Sun, and the different dusty plasma phenomena that are expected in each case, drawing on the earlier observations, including their interpretations and prevailing open questions.

Dust-acoustic wave modulation in the presence of q-nonextensive electrons and/or ions in dusty plasma

Abstract: A study is presented of the nonlinear self-modulation of low-frequency electrostatic dust acoustic waves (DAWs) propagating in a dusty plasma, within the theoretical framework of the nonextensive statistics proposed by Tsallis. Using the reductive perturbation method (RPM), the nonlinear Schrodinger equation (NLSE) which governs the modulational instability (MI) of the DAWs is obtained. The presence of the nonextensive electron/ion distribution is shown to influence the MI of the waves. Furthermore it is observed that nonextensive distributed ions has more effect on the MI of the DAW than electrons.

Dust-acoustic Gardner solitons and double layers in dusty plasmas with nonthermally distributed ions of two distinct temperatures

Abstract: A rigorous theoretical investigation has been performed on dust-acoustic (DA) solitary structures in an unmagnetized dusty plasma, consisting of negatively charged mobile dust grains, Boltzmann distributed electrons, and nonthermally distributed ions of two distinct temperatures. The Korteweg-de Vries (K-dV), modified K-dV (mK-dV) and Gardner equations, and their solitary waves (SWs) and double layer (DL) (in case of Gardner equation) solutions are derived by using the reductive perturbation technique. The basic features of the DA Gardner solitons (GSs) and DLs are studied analytically as well as numerically. It has been observed that the GSs significantly differ from K-dV and mK-dV solitons, and only positive potential DLs exist in the system. It is also studied that two-temperature nonthermal ions significantly modify the nature and basic properties of the DA SWs. The present investigation can be very effective for understanding and studying the nonlinear characteristics of the DA waves in laboratory and space dusty plasmas.

Effects of bi-kappa distributed electrons on dust-ion-acoustic shock waves in dusty superthermal plasmas

Abstract: The basic properties of dust-ion-acoustic (DIA) shock waves in an unmagnetized dusty plasma (containing inertial ions, kappa distributed electrons with two distinct temperatures, and negatively charged immobile dust grains) are investigated both numerically and analytically. The hydrodynamic equation for inertial ions has been used to derive the Burgers equation. The effects of superthermal bi-kappa electrons and ion kinematic viscosity, which are found to modify the basic features of DIA shock waves significantly, are briefly discussed.

Dust-ion-acoustic solitary waves and their multi-dimensional instability in a magnetized nonthermal dusty electronegative plasma

Abstract: A rigorous theoretical investigation has been made on multi-dimensional instability of obliquely propagating electrostatic dust-ion-acoustic (DIA) solitary structures in a magnetized dusty electronegative plasma which consists of Boltzmann electrons, nonthermal negative ions, cold mobile positive ions, and arbitrarily charged stationary dust. The Zakharov-Kuznetsov (ZK) equation is derived by the reductive perturbation method, and its solitary wave solution is analyzed for the study of the DIA solitary structures, which are found to exist in such a dusty plasma. The multi-dimensional instability of these solitary structures is also studied by the small-k (long wave-length plane wave) perturbation expansion technique. The combined effects of the external magnetic field, obliqueness, and nonthermal distribution of negative ions, which are found to significantly modify the basic properties of small but finite-amplitude DIA solitary waves, are examined. The external magnetic field and the propagation directions of both the nonlinear waves and their perturbation modes are found to play a very important role in changing the instability criterion and the growth rate of the unstable DIA solitary waves. The basic features (viz. speed, amplitude, width, instability, etc.) and the underlying physics of the DIA solitary waves, which are relevant to many astrophysical situations (especially, auroral plasma, Saturn’s E-ring and F-ring, Halley’s comet, etc.) and laboratory dusty plasma situations, are briefly discussed.

Langmuir probe analysis of highly electronegative plasmas

Abstract: A Langmuir probe analysis of highly electronegative plasmas is proposed. Analytical models are used to fit the IV-characteristics and their second derivatives above and below the plasma potential. Ion and electron densities are obtained for α (negative ion to electron density ratio) up to 3000, and the temperature of negative and positive ions is obtained for α ranging from 100 to 3000. The transport across a localized magnetic barrier is studied using this technique. It is shown that an ion-ion (electron free) plasma is formed downstream from the barrier at the highest magnetic field.

Dust ion-acoustic shock waves in nonextensive dusty plasma

Abstract: A parametric survey on the propagation characteristics of the dust ion-acoustic (DIA) shock waves showing the effect of nonextesivity with nonextensive electrons in a dissipative dusty plasma system has been carried out using the reductive perturbation technique. We have considered continuity and momentum equations for inertial ions, q-distributed nonextensive electrons, and stationary charged dust grains, to derive the Burgers equation. It has been found that the basic features of DIA shock waves are significantly modified by the effects of electron nonextensivity and ion kinematic viscosity. Depending on the degree of nonextensivity of electrons, the dust ion-acoustic shock structures exhibit compression and rarefaction. The implications of our results would be useful to understand some astrophysical and cosmological scenarios like stellar polytropes, hadronic matter and quark-gluon plasma, protoneutron stars, dark-matter halos, etc., where effects of nonextensivity can play the significant roles.

Effects of nonthermal ions of distinct temperatures on dust acoustic shock waves in a dusty plasma

Abstract: The nonlinear propagation of dust acoustic (DA) waves in an unmagnetized dusty plasma system consisting of negatively charged mobile dust fluid, Boltzmann distributed electrons, and two-temperature nonthermally distributed ions, is rigorously investigated. The reductive perturbation method has been employed to derive the Burgers equation. The hydrodynamic equation for inertial dust grains has been used to derive the Burgers equation. The effects of two temperature nonthermally distributed ions and dust kinematic viscosity, which are found to significantly modify the basic features of DA shock waves, are briefly discussed. Our present investigation can be effectively utilized in many astrophysical situations (e.g. satellite or spacecraft observations, Saturn’s E ring, etc.), which are discussed briefly in this analysis.

Magnetoplasmons in Rotating Dusty Plasmas

Abstract: A rotating dusty plasma apparatus was constructed to provide the possibility of experimental emulation of extremely high magnetic fields by means of the Coriolis force, observable in a corotating measurement frame. We present collective excitation spectra for different rotation rates with a magnetic induction equivalent of up to 3200 T. We identify the onset of magnetoplasmon-equivalent mode dispersion in the rotating macroscopic two-dimensional single-layer dusty plasma. The experimental results are supported by molecular dynamics simulations of 2D magnetized Yukawa systems.

Coulomb stable structures of charged dust particles in a dynamical trap at atmospheric pressure in air

Abstract: A mathematical simulation of a dust particle's behavior in the electrodynamic linear quadrupole trap with closing end electrodes allowed us to reveal several features of the phenomena Regions of stable confinement of a single particle, in dependence of frequency and charge-to-mass ratio, were determined With an increase of the medium's dynamical viscosity, the region for confining charged particles by the trap becomes wider We obtained values of the maximum quantities of charged particles confined by the trap at atmospheric pressure in air Firstly, we presented observations of ordered Coulomb structures of charged dust particles obtained in the quadrupole trap in air at atmospheric pressure The structures consisted of positively charged oxide aluminum particles 10?15??m in size and hollow glass microspheres 30?50??m in diameter The ordered structure could contain particles of different sizes and charges The trap could confine a limited number of charged particles The ordered structures of charged micro-particles obtained in the experiments can be used to study Coulomb systems without neutralizing the plasma background and action of ion and electron flows, which are always present in non-homogeneous plasma

Formation of layered structures of particles with anisotropic pair interaction

Abstract: The results of the numerical investigation of a layered structure formation in systems of particles with anisotropic pair interaction are presented. A simulation was carried out for extended homogeneous structures consisting of one or several layers of interacting particles over a wide range of parameters which correspond to the conditions usually observed in laboratory dusty plasma experiments. For the first time a detailed analysis of the development of various instabilities in such systems has been undertaken.

Bifurcations of dust ion acoustic travelling waves in a magnetized quantum dusty plasma

Abstract: Bifurcation behavior of nonlinear dust ion acoustic travelling waves in a magnetized quantum dusty plasma has been studied. Applying the reductive perturbation technique (RPT), we have derived a Kadomtsev-Petviashili (KP) equation for dust ion acoustic waves (DIAWs) in a magnetized quantum dusty plasma. By using the bifurcation theory of planar dynamical systems to the KP equation, we have proved that our model has solitary wave solutions and periodic travelling wave solutions. We have derived two exact explicit solutions of the above travelling waves depending on different parameters.

Higher order nonlinear equations for the dust-acoustic waves in a dusty plasma with two temperature-ions and nonextensive electrons

Abstract: The nonlinear propagation of dust-acoustic waves in a dusty plasma whose constituents are negatively charged dust, Maxwellian ions with two distinct temperatures, and electrons following q-nonextensive distribution, is investigated by deriving a number of nonlinear equations, namely, the Korteweg-de-Vries (K-dV), the modified Korteweg-de-Vries (mK-dV), and the Gardner equations. The basic characteristics of the hump (positive potential) and dip (negative potential) shaped dust-acoustic (DA) Gardner solitons are found to exist beyond the K-dV limit. The effects of two temperature ions and electron nonextensivity on the basic features of DA K-dV, mK-dV, and Gardner solitons are also examined. It has been observed that the DA Gardner solitons exhibit negative (positive) solitons for q qc) (where qc is the critical value of the nonextensive parameter q). The implications of our results in understanding the localized nonlinear electrostatic perturbations existing in stellar polytropes, quark-gluon plasma...

Dust-acoustic supersolitons in a three-species dusty plasma with kappa distributions

Abstract: Supersolitons are a form of soliton characterised, inter alia, by additional local extrema superimposed on the usual bipolar electric field signature. Previous studies of supersolitons supported by three-component plasmas have dealt with ion-acoustic structures. An analogous problem is now considered, namely, dust-acoustic supersolitons in a plasma composed of fluid negative dust grains and two kappa-distributed positive ion species. Calculations illustrating some supersoliton characteristics are presented.

Cylindrical and spherical dust-ion-acoustic modified Gardner solitons in dusty plasmas with two-temperature superthermal electrons

Abstract: A rigorous theoretical investigation has been performed on the propagation of cylindrical and spherical Gardner solitons (GSs) associated with dust-ion-acoustic (DIA) waves in a dusty plasma consisting of inertial ions, negatively charged immobile dust, and two populations of kappa distributed electrons having two distinct temperatures. The well-known reductive perturbation method has been used to derive the modified Gardner (mG) equation. The basic features (amplitude, width, polarity, etc.) of nonplanar DIA modified Gardner solitons (mGSs) have been thoroughly examined by the numerical analysis of the mG equation. It has been found that the characteristics of the nonplanar DIA mGSs significantly differ from those of planar ones. It has been also observed that kappa distributed electrons with two distinct temperatures significantly modify the basic properties of the DIA solitary waves and that the plasma system under consideration supports both compressive and rarefactive DIA mGSs. The present investigation should play an important role for understanding localized electrostatic disturbances in space and laboratory dusty plasmas where stationary negatively charged dust, inertial ions, and superthermal electrons with two distinct temperatures are omnipresent ingredients.

Effects of double temperature superthermal electrons on dust-ion-acoustic shock waves in electron-positron-ion dusty plasmas

Abstract: A rigorous theoretical investigation on the characteristics of dust-ion-acoustic (DIA) shock waves in an unmagnetized multi component electron-positron-ion dusty plasma (consisting of inertial ions, electrons of two distinct temperatures referred to as low and high temperature superthermal electrons where superthermality is introduced via the κ-type of nonthermal distribution, Boltzmann distributed positrons, and negatively charged immobile dust grains) has been made both theoretically and analytically. The hydrodynamic equation for inertial ions has been used to derive the Burgers equation. The influence of superthermal electrons, Maxwellian positrons and ion kinematic viscosity, which are found in this investigation, significantly modify the basic features of DIA shock waves, are briefly discussed. The present investigation can be very effective for studying and understanding the basic characteristics of shock wave propagation through different astrophysical situations where distinct temperature superthermal electrons dominate the wave dynamics.

Time dependent cylindrical and spherical DIA solitary waves with two populations of thermal electrons in dusty plasma

Abstract: The propagation of Gardner solitons (GSs) in a nonplanar (cylindrical and spherical) geometry associated with a dusty plasma whose constituents are non-inertial negative static dust, inertial ions, and two population of Boltzmann electrons with two distinctive temperatures, are investigated by deriving the modified Gardner (mG) equation using the reductive perturbation method. The basic features of nonplanar dust-ion-acoustic GSs are analyzed by numerical solutions of mG equation. It has been found that the basic characteristics of GSs, which are shown to exist for the values of μ c =n e10/n i0 around 0.319 for n e20/n i0=0.04 and T e1/T e2=0.2 [where n e10 (n e20) is the cold (hot) electron number density at equilibrium, T e1 (T e2) is the temperature of the cold (hot) electron species] are different from those of K-dV (Korteweg-de Vries) solitons, which do not exist around μ c ≃0.319. The implications of our results in understanding the nonlinear electrostatic perturbations observed in many laboratory and astrophysical situations (viz. double-plasma machines, rf discharge plasma, noctilucent cloud region in Earth’s atmosphere, source regions of Auroral Kilometric Radiation, Saturn’s E-ring, etc.) where electrons with different temperatures can significantly modify the wave dynamics, are also briefly discussed.

Nonlinear dust acoustic waves in inhomogeneous four-component dusty plasma with opposite charge polarity dust grains

Abstract: The reductive perturbation technique is employed to investigate the propagation properties of nonlinear dust acoustic (DA) waves in a four-component inhomogeneous dusty plasma (4CIDP). The 4CIDP consists of both positive- and negative-charge dust grains, characterized by different mass, temperature, and density, in addition to a background of Maxwellian electrons and ions. The inhomogeneity caused by nonuniform equilibrium values of particle densities, fluid velocities, and electrostatic potential leads to a significant modification to the nature of nonlinear DA solitary waves. It is found that this model reveals two DA wave velocities, one slow, λs, and the other is fast, λf. The nonlinear wave evolution is governed by a modified Kortweg-de Vries equation, whose coefficients are space dependent. Both the two soliton types; compressive and rarefactive are allowed corresponding to λs. However, only compressive soliton is created corresponding to λf. The numerical investigations illustrate the dependence of...

Three dimensional dust-acoustic solitary waves in an electron depleted dusty plasma with two-superthermal ion-temperature

Abstract: A theoretical investigation is carried out to study the existence and characteristics of propagation of dust-acoustic (DA) waves in an electron-depleted dusty plasma with two-temperature ions, which are modeled by kappa distribution functions. A three-dimensional cylindrical Kadomtsev-Petviashvili equation governing evolution of small but finite amplitude DA waves is derived by means of a reductive perturbation method. The influence of physical parameters on solitary wave structure is examined. Furthermore, the energy integral equation is used to study the existence domains of the localized structures. It is found that the present model can be employed to describe the existence of positive as well as negative polarity DA solitary waves by selecting special values for parameters of the system, e.g., superthermal index of cold and/or hot ions, cold to hot ion density ratio, and hot to cold ion temperature ratio. This model may be useful to understand the excitation of nonlinear DA waves in astrophysical objects.

Bohm criterion in a dusty plasma with nonextensive electrons and cold ions

Abstract: The Bohm criterion in a dusty plasma containing nonextensively distributed electrons and cold ions is investigated within the framework of probe model including the effects of dust charge fluctuation. It is shown that the critical Mach number upshifts with the decrease of electron nonextensive parameter (qe) and the increase of the ion-to-electron number density ratio (Rn) when the effects of dust charge fluctuation are out of consideration. Once the effects of dust charge fluctuation are included, with the increase of Rn, the critical Mach number increases first, then decreases. The slop of the critical Mach number curves in the region Rn≫1 for qe>1 becomes more gradual than that for qe<1. When critical Mach number is defined with respect to modified ion acoustic wave speed, it should be larger than unity in the case free of dust charge fluctuation. Whereas when Rn≫1, it may be smaller than unity due to the effect of dust charge fluctuation.

Head on collision of dust ion acoustic solitary waves in magnetized quantum dusty plasmas

Abstract: The Head on collision of dust ion acoustic solitary waves (DIASWs) in a magnetized quantum dusty plasma is investigated. Two sides Korteweg-de Vries (KdV) equations are obtained, the analytical phase shifts and the trajectories after the head-on collision of two DIASWs in a three species quantum dusty plasma are derive by using the extended version of Poincare-Lighthill-Kuo (PLK) method. It is observed that the phase shifts are significantly affected by the quantum parameters like quantum diffraction, the ion cyclotron frequency and the ratio of the densities of electrons to ions.

Dust acoustic solitary waves in a magnetized electron depleted superthermal dusty plasma

Abstract: A theoretical investigation has been made on the oblique propagation of arbitrary dust-acoustic solitary waves in an electron depleted magnetized dusty plasma which consists of kappa distributed ions and negatively charged warm dust fluid. The electron number density is assumed to be sufficiently depleted owing to the electron attachment during the dust charging process, i.e., ne≪ni. The propagation properties of two possible modes (in the linear regime) are investigated. It is found that deviation of ions from thermodynamic equilibrium leads to a decrease of the phase velocity of both modes. A nonlinear pseudopotential approach is employed to derive an energy-like equation which admits to investigate the occurrence of stationary solitary wave solution for the propagation of arbitrary amplitude. The effects of superthermality, obliqueness, and external magnetic field on the existence domain and nature of these solitary waves are discussed. Only negative polarity of solitary waves is found to exist. It is ...

Dust-ion-acoustic shock waves in a two-electron-temperature dusty plasma

Abstract: Properties of dust-ion-acoustic shock waves (DIASWs) in an unmagnetized dusty plasma (containing inertial ions, Maxwellian electrons with two distinctive temperatures and negatively charged immobile dust) are investigated. The hydrodynamic equation for inertial ions has been used to derive the Burgers equation. The effects of two-electron-temperature and ion kinematic viscosity, which are found to significantly modify the basic features of the DIASWs, are discussed.

Observation of Ω mode electron heating in dusty argon radio frequency discharges

Abstract: The time-resolved emission of argon atoms in a dusty plasma has been measured with phase-resolved optical emission spectroscopy using an intensified charge-coupled device camera. For that purpose, three-dimensional dust clouds have been confined in a capacitively coupled rf argon discharge with the help of thermophoretic levitation. While electrons are exclusively heated by the expanding sheath (α mode) in the dust-free case, electron heating takes place in the entire plasma bulk when the discharge volume is filled with dust particles. Such a behavior is known as Ω mode, first observed in electronegative plasmas. Furthermore, particle-in-cell simulations have been carried out, which reproduce the trends of the experimental findings. These simulations support previous numerical models showing that the enhanced atomic emission in the plasma can be attributed to a bulk electric field, which is mainly caused by the reduced electrical conductivity due to electron depletion.

Waves in a dusty plasma over the illuminated part of the Moon

Abstract: Waves in a dusty plasma over the lunar dayside are considered. It is shown that the relative motion of the solar wind with respect to the photoelectrons over the lunar surface leads to the excitation of high-frequency oscillations with frequencies in the range of Langmuir and electromagnetic waves. The dust acoustic wave excitation is possible in the vicinity of the lunar terminator.