Dust Ion Research Articles

Parametric study of cylindrical and spherical dust ion acoustic shock waves with two temperature electrons in dusty plasma relevant to Saturn's E ring

AbstractWe have performed numerical analysis of the one‐dimensional dynamics of the cylindrical/spherical dust ion acoustic shock waves in unmagnetized dusty plasma consisting of positive ions, immobile dust particles, and nonextensive distributed cold and hot electrons. A multiple‐scale expansion method is used to derive Burgers Equation (BE) and modified Burgers equation (MBE) by including higher order nonlinearity. The basic characteristics of the shock waves have been analysed numerically and graphically for different physical parameters relevant to Saturn' E ring through 2D figures. The parametric dependence of dust ion acoustic shock waves on some plasma parameters nonextensive index, density, and temperature of cold and hot electrons, concentration of dust particles, thermal effects and kinematic viscosity of ions is explored. Furthermore, it is found that the nonplanar geometry effects have an important impact on the establishment of shock waves. The amplitude of the wave decreases faster as one departs away from the axis of the cylinder or centre of the sphere. Such decaying behaviour continues as time progresses. It is also found that an increasing dust concentration decreases the amplitude of the dust ion acoustic shock waves.

Dust-Ion-Acoustic waves in unmagnetized 4-component plasma

A theoretical study is presented for the propagation of Dust Ion Acoustic Waves in an unmagnetized four-component plasma, consisting of Maxwellian negative ions, cold mobile positive ions, κ-distributed electrons and positively charged dust grains. Based on the characteristics of Sagdeev pseudopotential and phase portraits, three types of nonlinear waves are observed – solitons, double layers and supersolitons. The conditions for the existence of such nonlinear waves are highly sensitive to the plasma parameters. The results obtained in this study may be of wide relevance in the field of space plasma as well as ultrasmall semiconductor devices in the laboratory.

Gravitational instability with dust charge gradient and ion drag forces in unmagnetized dusty plasma

The influence of dust charge gradient force and ion drag force on the fragmentation of unmagnetized, self-gravitating dust cloud has been studied. The thermal electrons satisfy the Boltzmann relation, while inertialess ions are affected by the ion-neutral collisions. The dynamics of dusty fluid are modified by ion drag, charge gradient, and gravitational forces. The onset criterion of pinching instability and gravitational instability is derived. The pinching instability depends upon the critical ion drag coefficient and dust charge variation parameter. In the laboratory complex plasma, with finite dust charge variations, the ion drag coefficient larger than the critical value causes pinching instability. This results in the fragmentation of the dusty cloud, which is affected due to the dust charge variations. The ion drag coefficient has destabilizing, while the dust charge variation parameter has stabilizing influence on the growth rate of the linear gravitational instability. The results have been discussed to understand the dust cloud collapse in the astrophysical system.

Relativistic Effect of Electrons on Dust Acoustic Solitary waves in unmagnetized plasma

In this paper, we study dust acoustic solitary waves (DASW) based on the dust charge Zd =equilibrium density of ions / equilibrium density of dust ions , initial dust speed do Udo and initial streaming speed \nueo of electrons with the introduction of relativistic effect. Only rarefactive solitons are found to exist in the unmagnetized dusty plasma in presence of relativity for electrons. It is observed that for greater values of dust charge Zd rarefactive solitons exist.

Analytical solitary wave solution of dust ion acoustic waves in nonextensive plasma in the framework of damped forced Korteweg–de Vries–Burgers equation

Dust ion acoustic waves (DIAWs) are investigated analytically in the framework of damped forced Korteweg–de Vries–Burgers (DFKdVB) equation in an unmagnetized collisional dusty plasma consisting of negatively charged stationary dust grains, positively charged ions and q-nonextensive distributed electrons. Reductive perturbation technique is used to obtain the DFKdVB equation for DIAWs. The effects of different physical parameters such as the entropic index (q), ratio of unperturbed number densities of electrons and ions $$(\mu )$$ , dust ion collision frequency $$(\nu _{\mathrm{id}0})$$ , kinematic viscosity ( $$\eta _0$$ ), the speed of the traveling wave $$(M_0)$$ , strength $$(f_0)$$ and frequency $$(\omega )$$ of the external periodic force on the analytical DIAWs are shown. The results of the present paper will be useful in laboratory and space plasmas.

Dust Ion Acoustic Solitary Waves in Unmagnetized Plasma with Kaniadakis Distributed Electrons

The propagation of dust ion acoustic solitary waves (DIASWs) is investigated in dusty plasma with non-Maxwellian electrons. The Korteweg-de Vries (KdV) equation and modified Korteweg-de Vries (mKdV) equation are derived with the help of reductive perturbation method and their solitary wave solutions are analyzed. The effects of relevant parameters (viz., κ-deformed parameter and dust concentration μ) on the dynamics of solitary structures are discussed in detail.

Simulations of ion–dust streaming instability in a highly collisional plasma

The excitation of low frequency dust acoustic (or dust density) waves in a dusty plasma can be driven by the flow of ions relative to dust. We consider the nonlinear development of the ion–dust streaming instability in a highly collisional plasma, where the ion and dust collision frequencies are a significant fraction of their corresponding plasma frequencies. This collisional parameter regime may be relevant to dusty plasma experiments under microgravity or ground-based conditions with high gas pressure. One-dimensional particle-in-cell simulations are presented, which take into account collisions of ions and dust with neutrals, and a background electric field that drives the ion flow. Ion flow speeds of the order of a few times thermal are considered. Waveforms of the dust density are found to have broad troughs and sharp crests in the nonlinear phase. The results are compared with the nonlinear development of the ion–dust streaming instability in a plasma with low collisionality.

The possibility of relaxation in Quadruple Beltrami states in a four-component magneto dusty plasma

The possibility of relaxation in Quadruple Beltrami states for a system of dusty plasma of opposite polarity dust particles, electrons, and ions has been investigated. The macroscopic magnetic field structures are investigated in alliance with the differential flows of electrons, ions, positively and negatively charged dust grains. For a certain set of Beltrami parameters, it is observed that the system self-organized to Quadruple Beltrami state which is characterized by four eigenvalues. To derive Quadruple Beltrami equation, two different cases are assumed. The system allows a fully diamagnetic structure by considering all the inertial forces. The development of paramagnetic and diamagnetic structures has been observed by just ignoring the inertial effects of electrons. It has been shown that the features (paramagnetic or diamagnetic) of the relaxed structures are significantly modified by the eigenvalues and masses of the oppositely charged dust particles.

Soliton turbulence in electronegative plasma due to head-on collision of multi solitons

Abstract Head-on interaction of four dust ion acoustic (DIA) solitons and the statistical properties of the wave field due to head-on interaction of solitons moving in opposite direction is studied in the framework of two Korteweg de Vries (KdV) equations. The extended Poincaré–Lighthill–Kuo (PLK) method is applied to obtain two opposite moving KdV equations from an unmagnetized four component plasma model consisting of Maxwellian negative ions, cold mobile positive ions, κ-distributed electrons and positively charged dust grains. Hirota’s bilinear method is adopted to obtain two-soliton solutions of both the KdV equations and accordingly act of soliton turbulence is presented due to head-on collision of four solitons. The amplitude and shape of the resultant wave profile at the point of strongest interaction are obtained. To see the effect of head-on collision on the statistical properties of wave field the first four moments are computed. It is observed that the head-on collision has no effect on the first integral moment while the second, third and fourth moments increase in the dominant interaction region of four solitons, which is a clean indication of soliton turbulence.

Dust Ion–Acoustic Shock Waves in Laboratory, Ionospheric, and Astrophysical Plasmas

Methods of description of ion–acoustic shock waves in dusty plasma are presented. A new type of dust ion–acoustic shock waves related to anomalous dissipation is described. The main dissipative processes related to charging of dust particles, absorption of ions by dust particles, Coulomb collisions between ions and dust particles, and Landau damping are analyzed. Proposed methods of theoretical analysis enable explaining all major specific features of dust ion–acoustic shock waves observed in the laboratory experiments. The shock waves of this type are present in the near-Earth plasma and the universe. Their investigation is possible in active ionospheric experiments of the Fluxus type. Important astrophysical problems in which the appearance of shock waves under consideration should be taken into consideration are the shock waves of supernovas, evolution of Local Interstellar medium, etc.

Dust as probes: Determining confinement and interaction forces.

Complex plasmas are interesting systems as the charged dust can self-assemble into different types of ordered structures. To understand the mechanisms which govern the transitions from one type of structure to another, it is necessary to know both the dust charge and the confining electric fields within the environment, parameters which are difficult to measure independently. As dust is usually confined in a plasma sheath where the ions stream from the bulk plasma to the negative lower electrode, the problem is further complicated by the ion wake field, which develops downstream of the dust grains in a flowing plasma. The differences in local ion density caused by the wake field change the equilibrium dust charge and shielding distance of the dust grains, and thus affect the interaction between grains. Here we use a molecular dynamics simulation of ion flow past dust grains to investigate the interaction between the dust particles and ions. We consider a long vertical chain of particles confined within a glass box placed on the lower electrode of a Gaseous Electronics Conference rf reference cell. We apply the model iteratively to self-consistently determine the dust charge, electric field, and ion density along the length of the chain as well as the ion flow speed. Simulation results indicate that the ion flow speed within the box is subsonic.

Variation in recent annual snow deposition and seasonality of snow chemistry at the east Greenland ice core project (EGRIP) camp, Greenland

We collected snow samples from two pits with depths of 4.02 and 3.18 m at the East Greenland Ice Core Project camp (75°37′N, 35°59′W), Greenland in the summer of 2016 to estimate recent annual snow deposition and examine seasonal variation in major ion species, stable isotopes of water and microparticles (dust). Dating based on clear seasonal variation in chemical components indicated that the 4.02- and 3.18-m-deep pits included snow deposition corresponding to ten years from 2006 to 2016 and seven years from 2009 to 2016, respectively. The mean values for annual snow deposition for the 4.02-m-deep pit were 138 and 145 mm yr−1 in water equivalent (mm w.e. Yr−1) in 2006–2016 and 2009–2016, respectively. The average deposition for the 3.18-m-deep pit was 149 mm w.e. Yr−1 between 2009 and 2016. Seasonal variation in concentrations of major ion species and dust were similar to those previously reported for Greenland. The maximum Cl−/Na+ concentration ratios in the summer were much higher than the ratios at other sites in Greenland.

Effect of non-thermal electron and positron on the dust ion acoustic solitary wave in the presence of relativistic thermal magnetized ions

The propagation characteristics of small-amplitude electrostatics solitary wave in magnetized dusty plasma in the presence of relativistic thermal ion with non-thermal electron and positron are investigated. Here, Zakharov–Kuznetsov (Z–K) equation is studied to observe the evolution of dust ion acoustic solitary waves with the help of perturbative procedures. In the present plasma system, the Mach number (phase velocity) is found to be in the supersonic range and it decreases (increases) with normalized positron density (thermal ion parameter). On the other hand, the plasma system behaves in the least nonlinear way when the non-thermal parameter of electrons and positrons has the lowest value allowing the solitary wave potential to propagate with maximum value. It is found that the non-thermal parameters of electrons and positrons, relativistic factor and dust density, can effectively control the variation of Mach number. The solitary wave potential has the least value when the thermal ion parameter increases, whereas it is the highest when the positron density has the highest.

Dust ion acoustic solitons in a complex dusty plasma system with an adiabatic state

In this theoretical work nonlinear behavior of dust ion acoustic solitary waves (SWs) has been investigated, and then the effect of the adiabatic change on them has been observed. The complex plasma system consists of inertial positive and negative ions, Maxwell's electrons, and positively and negatively charged stationary dust particles. The effects of dust polarity on the dust ion acoustic SWs have also been observed. Using the reductive perturbation method, we first derive K-dV equation which lets to analyze both the positive (bright) and negative (dark) solitons in a very limited region. After that mK-dV equation has been derived, and this let to analyze positive soliton for a large region, but cannot show the negative soliton. Finally, the Gardner equation has been derived employing the same method, through which we were able to analyze both the positive and negative solitons for a large region. It has been found that both the positive and negative solitons significantly depend on the mass number density, ion number density, and dust polarity in the adiabatic and isothermal system.

Inverse problem of the cylindrical Korteweg-de Vries equation for dust ion acoustic waves in unmagnetised plasma

Inverse problem of the cylindrical Korteweg-de Vries equation for dust ion acoustic waves in unmagnetised plasma

Propagation and interaction of dust ion acoustic solitary waves(DIASWs) for the damped forced modified Korteweg-de-Vries-Burger equation at some critical composition of parameters

The analytical solution of dust-ion-acoustic-solitary waves (DIASWs)with the influence of external periodic force are reported in a dusty plasma model which consists of dust-ion collisions. Using reduction perturbation technique (RPT) damped modified forced Korteweg-de-Vries-Burger (DMFKdVB)equation in some critical composition is obtained. Various physical parameters i.e. dust ion collision frequency (νid0), the entropic index (q), the velocity of travelling wave (M0) ,the ratio of the densities between electrons and ions (μ), viscosity coefficient (η), frequency (w) of the external perturbation and the strength(f0) of the perturbation are observed. This study may be helpful to interpret the characteristics of DIASWs in astrophysical rings, interstellar clouds and comet tails.

Analysis of periodic and solitary waves in a magnetosonic quantum dusty plasma

The propagation of nonlinear magnetosonic waves in electron–ion–dust (complex) plasmas has been studied by considering the effects of Bohm potential in the presence of an external magnetic field. By using the quantum hydrodynamic model and applying the reductive perturbation method, the Kadomtsev–Petviashvili (KP) equation is obtained. The compressive structures of magnetosonic solitary waves and periodic travelling waves are studied. The effects of the electron to dust density ratio, the quantum plasma parameter, and the dust equilibrium density on the nonlinear magnetosonic periodic travelling waves are discussed. It is observed that the wave structure is more sensitive to the changes in the ratio of electron to dust densities, as compared to the changes in other physical parameters. The obtained results may be useful for a better understanding of obliquely nonlinear magnetosonic travelling waves of localized structures with a small amplitude in dense magnetized quantum dusty plasmas.

Three-dimensional dusty plasma in a strong magnetic field: Observation of rotating dust tori

This paper reports on the dynamics of a 3-dimensional dusty plasma in a strong magnetic field. An electrostatic potential well created by a conducting or non-conducting ring in the rf discharge confines the charged dust particles. In the absence of the magnetic field, dust grains exhibit a thermal motion about their equilibrium position. As the magnetic field crosses a threshold value (B > 0.02 T), the edge particles start to rotate and form a vortex in the vertical plane. At the same time, the central region particles either exhibit thermal motion or E→×B→ motion in the horizontal plane. At B > 0.15 T, the central region dust grains start to rotate in the opposite direction resulting in a pair of counter-rotating vortices in the vertical plane. The characteristics of the vortex pair change with increasing the strength of the magnetic field (B ∼ 0.8 T). At B > 0.8 T, the dust grains exhibit very complex motion in the rotating torus. The angular frequency variation of rotating particles indicates a differential or sheared dust rotation in a vortex. The angular frequency increases with increasing the magnetic field from 0.05 T to 0.8 T. The ion drag force and dust charge gradient along with the E-field are considered as possible energy sources for driving the edge vortex flow and central region vortex motion, respectively. The directions of rotation also confirm the different energy sources responsible for the vortex motion.

Dust ion acoustic multi-shock wave excitations in the weakly relativistic plasmas with nonthermal nonextensive electrons and positrons

This article investigates the dust ion acoustic multi-shock wave excitations in weakly relativistic multi-component plasma by assuming nonthermal, nonextensive electrons and positrons, relativistic ion fluid having kinetic viscosity and immobile dust. Burgers equation is derived to investigate such excitations by applying the reductive perturbation method. The exponential functions are directly implemented to determine the novel multi-shock wave solution of Burgers equation. The dust ion acoustic (DIA) multi-shock wave excitations are investigated systematically to reveal the effects of parameters, namely, viscosity coefficient of ions, positron to electron density ratio, immobile dust to electron density ratio, ion to electron temperature ratio, electron to positron temperature ratio, and relativistic streaming factor of ions in the presence of nonthermal, nonextensive, and concurrently acting nonthermal and nonextensive electrons as well as positrons. It is found that the amplitudes and widths of not only single, but also multi-shock wave compressive and rarefactive electrostatic potential structures are changed with the influence of all plasma parameters. The obtained results may be useful to analyze the nature of DIA multi-shock wave phenomena in various astrophysical as well as space environments (particularly, in pulsar relativistic winds with supernova ejecta) and future studies in plasma laboratory.

Nonlinear Wave Interaction with Positron Beam in a Relativistic Plasma: Evaluation of Hypersonic Dust Ion Acoustic Waves

We studied the propagation of small-amplitude dust ion acoustic (DIA) solitary waves in four-component relativistic plasma comprised of nonthermal electrons, mobile positively charged ions, positron beam and negatively charged massive dust particles. By using the reductive perturbation method, the Korteweg–de-Vries (KdV) nonlinear wave equation is derived numerically. In this work, we have elucidated the role of energetic positron beam in the relativistic plasma and analyzed the existence region for ion-acoustic (IA) solitary wave formation. It is found that for certain plasma parameters, the propagation of both compressive and rarefactive solitary waves is possible. Here, the injecting streaming positron beam in plasma gives rise to the increase in the phase velocity (Mach number) and reaches up to the hypersonic regime of flow velocity. It is observed that the initial increase in relativistic factor of positron beam $${{\gamma }_{{{\text{br}}}}}$$, as well as temperature ratio of the positron beam to electrons $${{\sigma }_{{\text{b}}}}$$ decrease the characteristic features (the amplitude) of the compressive solitary wave potential profiles. On the other hand, on increasing dust grain charge $${{Z}_{{{\text{d0}}}}}$$, positron beam concentration ratio $${{\mu }_{{\text{b}}}}$$ as well as nonthermal electrons concentration result in enhancement of the amplitudes of IA solitary wave potential profiles. The findings of this work can be more helpful in understanding the Earth’s upper atmosphere (Aurora region of the ionosphere) as well as the space plasmas.