Charged Dust Particles Research Articles

Spike-Like Traveling Waves at the Critical Point of Bifurcation in a Nonextensive Dusty Plasma With Dust Polarity

This article presents a detailed study on the basic features of bifurcation of dust ion acoustic (DIA) traveling waves in a dusty plasma comprising warm adiabatic ions, nonextensive electrons, and arbitrarily charged dust particles. A reduced dynamical system is obtained for plasma waves’ evolution, and the global dynamics of local bifurcation of waves’ motion are determined on the equilibrium points’ dust concentrations’ plane with respect to all possible plasma parametric combinations. The stability and phase portrait analysis indicate a sudden emergence of nonlinear periodic and solitary waves for critical values of negative (positive) dust concentration. At these critical values, waves’ dynamics exhibit a transcritical bifurcation with half-stable fixed points which support new spike-like traveling waves. The analytical and numerical solutions reveal that the decay rate of this localized structure is much slower than ordinary solitary waves that decay exponentially fast. Furthermore, the existence domain of bifurcation parameters and transitions between modes are found for different values of nonextensive electrons and arbitrarily charged dust concentrations. Our results could be applicable to different space and astrophysical plasma systems, particularly in earth atmosphere.

Electrostatic dust removal using adsorbed moisture-assisted charge induction for sustainable operation of solar panels.

Dust accumulation on solar panels is a major challenge, as it blocks a large portion of sunlight. Solar panels are therefore cleaned regularly using large quantities of pure water. Consumption of water for cleaning, especially in deserts, poses a substantial sustainability challenge. Here, we present a waterless approach for dust removal from solar panels using electrostatic induction. We find that dust particles, despite primarily consisting of insulating silica, can be electrostatically repelled from electrodes due to charge induction assisted by adsorbed moisture. We experimentally determine dust particle charge by conducting Stokes experiments under an electrostatic field. By considering electrostatic, van der Waals, and gravitational forces, we define the threshold electric potential for particle removal. We also demonstrate dust removal over a broad range of relative humidity, making our approach widely applicable. Last, we develop a lab-scale prototype and demonstrate up to 95% recovery of lost power output using our approach.

Effect of dust polarity on transcritical bifurcation of dust ion-acoustic waves in a nonextensive dusty plasma

In this paper, we combine bifurcation techniques and numerical simulations to fully analyze the nonlinear propagation of dust ion-acoustic waves in a complex dusty plasma consisting of warm adiabatic ions, nonextensive electrons, and negatively (positively) charged dust particles. An autonomous dynamical system is derived which captures the main features of traveling wave solutions and transition between nonlinear modes. It is shown that for a range of electron nonextensivity and negative (positive) dust concentration, there are different existence domains of stability regions. At the critical points of nonextensivity parameter and dust concentration, we show that the motion dynamics of low-frequency dust ion-acoustic traveling waves undergoes a transcritical bifurcation, where two equilibrium points coalesce, and then switch their stability. A new kind of solitary structure is also observed which is characterized by the transcritical bifurcation parameters with half-stable equilibrium points. It is found that an increase in negative (positive) dust concentration leads to the appearance of bifurcation points at larger (smaller) values of electron nonextensivity. In accordance with the phase portraits analysis, the coexistence of homoclinic orbits, nonlinear periodic and supernonlinear periodic orbits are also investigated for different conditions. It is shown that the nonextensive parameter and dust polarity play a crucial role in the transition between nonlinear traveling waves.

Influence of Metastable Argon Atoms and Dust Particles on Gas Discharge Plasma

The model of a DC glow discharge with metastable argon atoms and dust particles based on the Boltzmann equation for the electron energy distribution function (EEDF), dust particle charging, and balance equation for metastable argon atoms is presented. The processes of direct and stepwise electron impact ionization, metastable-metastable collisions, and recombination of electrons and ions on the dust particle surface and discharge tube wall are taken into account. The results show that the densities of metastable argon atoms and dust particles are in strong correlation, and both sufficiently influence gas discharge parameters.

Quantitative simulations of ratchet potential in a dusty plasma ratchet

Using a dusty plasma ratchet, one can realize the rectification of charged dust particle in a plasma. To obtain the ratchet potential dominating the rectification, here we perform quantitative simulations based on a two-dimensional fluid model of capacitively coupled plasma. Plasma parameters are firstly calculated in two typical cross sections of the dusty plasma ratchet which cut vertically the saw channel at different azimuthal positions. The balance positions of charged dust particle in the two cross sections then can be found exactly. The electric potentials at the two balance positions have different values. Using interpolation in term of a double-sine function from previous experimental measurement, an asymmetrical ratchet potential along the saw channel is finally obtained. The asymmetrical orientation of the ratchet potential depends on discharge conditions. Quantitative simulations further reproduce our previous experimental phenomena such as the rectification of dust particle in the dusty plasma ratchet.

Influence of an external electric field on plasma parameters around an isolated dust particle

The paper presents new numerical results on the behavior of plasma parameters around an isolated chargeddust particle under the action of the external electric field. For the first time, the model takes into account thedependence of mean electron energy on the reduced electric field strength. As a result of the calculations, thedependencies of self-consistent spatial distributions of the electron and ion densities and electric potentialaround the dust particle on reduced external electric field strength were obtained. These distributions wereanalyzed through the expansion into Legendre polynomials. The processes of ion focusing wakeformation behind the dust particle were studied. The dust particle charge and the dipole moment of the“ion cloud - dust particle” are calculated for different values of the reduced electric field and ion mean freepaths. It is shown that in the determination of electron density spatial profile and the dust particle charge thedependence of electron temperature on electric field strength plays a significant role. Key words: dusty plasma, dust particle charging, dipole moment, wake, plasma polarization.

Dust dynamics during the plasma afterglow

The charge and dynamics of dust particles in an afterglow plasma are studied using a 1D model in the diffusion approximation, taking into account the transition from ambipolar to free diffusion. It is analyzed how external conditions (dust particle size, neutral gas pressure and initial electron density) affect the dust motion. The dust particle dynamics has been examined in microgravity conditions and in presence of gravity. Without gravity, the location of dust particles in plasma volume may change essentially during the afterglow if the dust size and pressure are small (⩽10 nm and ⩽30 mTorr, respectively). At small pressures, in the very beginning of afterglow, small nanoparticles move to the plasma boundary because the ion drag force dominates over the electric force. At afterglow times when the electron temperature becomes time-independent, the ion drag force decreases faster with time than the electric force due to the ion density decrease, and dust particles may move to the slab center. In presence of gravity, the effect of gravity force on dust particles is important only at large afterglow times (t ⩾ 10 ms), when the electric and ion drag forces are small. The dust dynamics depends essentially on the initial plasma density. If the density is large (∼1012 cm−3), small nanoparticles (⩽10 nm) may deposit on plasma walls in the beginning of plasma afterglow because of an enhancement of the ion drag force.

Modulational Interaction in a Dusty Plasma of Meteoroid Wakes

This is a study of the possible modulational instability of electromagnetic waves in meteoroid wakes associated with the dust acoustic mode at altitudes of 80–120 km, which is a linear stage of modulational interaction. The parameters of meteoroid wakes at different altitudes in the Earth’s ionosphere are considered. It is shown that the charging of dust particles of meteoric matter creates conditions for the occurrence of dust acoustic waves. Dust acoustic disturbances are excited due to the modulational instability of electromagnetic waves from the meteoric trail. The influence of neutrals on the development of modulational interaction is taken into account. The concentration of neutrals in meteoric wakes is higher than the concentration of neutrals in the Earth’s ionosphere. It has been found that the condition for the excitation of a dust acoustic wave is satisfied for the typical parameters of dusty plasma of meteoroid wakes at altitudes of 100–120 km. Due to collisions between dust and neutrals, the development of modulation instability is suppressed at altitudes of 80–90 km, while inelastic collisions of neutrals with electrons and ions do not affect the development of modulational instability. The modulational instability of electromagnetic waves can explain the occurrence of low-frequency noise during the passage of meteoric bodies in a frequency range characteristic of dust acoustic waves. It is shown that the modulation instability has time to develop for characteristic temperatures and particle concentrations in meteoroid wakes. Equations for the charging of dust particles in meteoroid wakes are given. It has been found that the dust is positively charged, both in the daytime and at night, due to intense emission currents from the surface of dust particles.

Scattering Cross Section of Charged Dust Particles in Magnetized Plasma

Dust particles in magnetized plasma have generated considerable interest in the semiconductor industry, plasma crystals, Tokamaks, cosmological events, and so on. Upon introducing dust particles in dc glow discharge plasma, they get charged, and hence, a potential is developed surrounding the same. Coulomb potential or Yukawa potential is taken for the interaction of charged dust particles. The effect of magnetic field along the axis of the chamber and, subsequently, scattering cross section of charged dust particles due to the interaction of magnetic fields have been studied critically in this report. A generalized mathematical model is implemented, to find the scattering cross section of charged dust particles. The scattering parameter is introduced to reduce the complexity involved in the derivation of integral equations. Furthermore, to validate the mathematical model, the simulation of DC glow discharge plasma in COMSOL Multiphysics has been carried out. A rectangle chamber with charged dust particles is introduced and with varying magnetic fields, and the transport of dust particles is recorded. The scattering cross section of dust particles is determined from the velocity profile of dust particles and it has been observed that the scattering cross section decreases with the increase of the magnetic field.

Obliquely overtaking collisions of electrostatic N-soliton in the Thomas-Fermi dense magnetoplasma

Overtaking collision of unidirectional dust acoustic waves in the Thomas-Fermi dense magnetoplasma has been investigated. The system consists of classical negatively charged dust particles with degenerate electrons and ions. Nonlinear Korteweg-de Vries (KdV) equation that characterizing the dust acoustic solitons in such a plasma model is derived. The system admits only rarefactive solitary waves. Hirota's bilinear method is used to investigate the overtaking collision of two and three-soliton solutions. The exchange of energies due to the overtaking collisions is affected by physical parameters such as the electron equilibrium density, the dust temperature, and the obliquity angle. This causes the solitons behavior to be alternated. The amplitude, and width increase as the dust temperature and electron density decrease or when the dust density increases. The magnetic field affects only the soliton's width. The phase shifts are also affected by the system parameters. The current study is an attempt to illuminate the properties of N-soliton in Thomas-Fermi dense magnetoplasma that are applicable in compact astrophysical objects such as white dwarfs and high-intensity laser-solid matter interaction experiments.

Nonlinear excitations and dynamic features of dust ion-acoustic waves in a magnetized electron–positron–ion plasma

Abstract A wide class of nonlinear excitations and the dynamics of wave groups of finite amplitude ion-acoustic waves are investigated in multicomponent magnetized plasma system comprising warm ions, and superthermal electrons as well as positrons in presence of negatively charged impurities or dust particles. Employing the reductive perturbation technique (RPT), the Korteweg–de-Vries (KdV) equation, and extended KdV equation are derived. The presence of excess superthermal electrons as well as positrons and other plasma parameters are shown to influence the characteristics of both compressive and rarefactive solitons as well as double layers (DLs). Also, we extend our investigation by deriving the nonlinear Schrödinger equation from the extended KdV equation employing a suitable transformation to study the wave group dynamics for long waves. The analytical and numerical simulation results demonstrate that nonlinear wave predicts solitons, “table-top” solitons, DLs, bipolar structure, rogue waves, and breather structures. Moreover, implementing the concept of dynamical systems, phase portraits of nonlinear periodic, homoclinic trajectories, and supernonlinear periodic trajectories are presented through numerical simulation.

Trajectory optimization for the Horyu-VI international lunar mission

The Horyu-VI nano-satellite is an international lunar mission with the purpose of studying the lunar horizon glow (LHG)—a still unclear phenomenon caused by electrostatically charged lunar dust particles. This study analyzes the mission trajectory with the hypothesis that it is launched as a secondary payload of the NASA ARTEMIS-II mission. In particular, the effect of the solar gravity gradient is studied; in fact, depending on the starting relative position of the Moon, the Earth, and the Sun, the solar gradient acts differently on the trajectory—changing it significantly. Therefore, the transfer and lunar capture problem is solved in several cases with the initial Sun–Earth–Moon angle as the key parameter. Furthermore, the inclination with respect to the Moon at capture is constrained to be equatorial. Finally, the problem of stabilization and circularization of the lunar orbit is addressed in a specific case, providing an estimate of the total propellant cost to reach the final orbit around the Moon.

Dynamics of nanodust in the vicinity of a stellar corona: Effect of plasma corotation

Context. In the vicinity of the Sun or other stars, the motion of the coronal and stellar wind plasma must include some amount of corotation, which could affect the dynamics of charged dust particles. In the case of the Sun, this region is now investigated in situ by the Parker Solar Probe. Charged dust particles coming from the vicinity of the Sun can also reach, and possibly be detected by, the Solar Orbiter. Aims. We use numerical simulations and theoretical models to study the effect of plasma corotation on the motion of charged nanodust particles released from the parent bodies moving in Keplerian orbits, with particular attention to the case of trapped particles. Methods. We used two methods: the motion of nanodust is described either by numerical solutions of full equations of motion, or by a two-dimensional (distance vs. radial velocity) model based on the guiding centre approximation. The models of the plasma and magnetic field in the vicinity of the star are based on analytical solutions that satisfy the freezing-in equations. Results. Including plasma corotation does not prevent trapping of nanodust in the vicinity of the Sun or other stars. This result can be understood with the help of the model based on the guiding centre approximation. For the amount of corotation expected near the Sun, the outer limit of the trapped region is almost unaffected. If the corotation persists outside the trapping region, the speed of particles ejected from the Sun is moderately increased. A strong effect of plasma corotation on charged particle dynamics occurs for the star with a high rotation rate and/or a low value of the stellar wind speed.

Energy exchange in two-fraction systems of charged dust particles

A study of the processes of redistribution of stochastic kinetic energy between two fractions of dust particles with different sizes and temperatures, as well as its redistribution by degrees of freedom, is presented for conditions close to the conditions of experiments in gas-discharge plasma. The numerical simulation was carried out for two-layer ensembles and bulk clouds of charged particles in the gravity field, and for two-dimensional structures formed in the external electric fields under the influence of forces proportional to the square of dust radius. The influence of high temperatures on the energy balance in the analyzed systems is considered. A semiempirical approximation is proposed, which well describes the energy exchange in all considered cases.

Effect of Asymmetry Induced by Staggered Angle on the Rectification of Dust Particles in a Dusty Plasma Ratchet

Converting random motion into directional motion of charged dust particles in plasma, i.e., the rectification, can be achieved by using a dusty plasma ratchet, in which the asymmetry of system plays a very important role. Here, we use different staggered angles between the inner and outer gears to control the asymmetry of system and further study experimentally the effect of the asymmetry induced by staggered angle on the rectification of dust particles in a dusty plasma ratchet. Our results show that the spatial distribution and the velocity of dust particles along the saw channel are nonuniform. Decreasing the asymmetry can reduce the flow of dust particle in the saw channel.

Rotation of dust particles in an inhomogeneous weak magnetic field in a DC glow discharge

We report an explanation for the opposite direction of the rotation of the charged dust particles above and below the Helmholtz coil in an inhomogeneous weak magnetic field in the direct current glow discharge. Experiments with monodispersed melamine-formaldehyde particles were performed in an argon plasma in an inhomogeneous weak magnetic field (with the induction values 4, 12, and 18 mT). The linear and angular velocities of rotational motion of the clusters of dust particles formed in regions with an inhomogeneous weak magnetic field above and below the Helmholtz coil were analyzed. The peculiarity is that the directions of rotation in these areas are opposite, whereas there is no rotational motion in the region of a uniform magnetic field. To explain these observations, the theoretical model that takes into account the magnetic field inhomogeneity and provides good agreement with experimental data is presented.

Particle charge distributions in the effluent of a flow-through atmospheric pressure low temperature plasma

Atmospheric pressure low-temperature plasmas are often utilized to perform particle synthesis, treatment, and removal. It is well-known that dust particles are highly negatively charged in these plasmas; however, little is known about dust particle charging behavior as particles leave the plasma volume and pass through the spatial afterglow region. In this work, monodisperse particles of various sizes and work functions were introduced into an atmospheric pressure radiofrequency capacitively coupled flow-through plasma. Dust particle electrical mobility distributions downstream of the flow-through plasma were measured utilizing a differential mobility analyzer in conjunction with a condensation particle counter at various gas flow velocities. Charge distributions were determined from the measured electrical mobility distributions. Experiments confirm that particles become less negatively charged, and even net-positively charged after leaving the plasma volume, with a distribution that follows a shifted Boltzmann charge distribution. Additionally, particle charge in the effluent of the flow-through plasma is negligibly dependent on work function but highly size and flow velocity dependent. Larger particles were shown to have a higher magnitude of charge under all studied conditions; however, particle polarity was switchable by varying gas flow velocity. The charging dynamics were simulated utilizing a constant number Monte Carlo model that accounts for electron temperature decay and the transition from ambipolar to free diffusion of electrons and ions in the spatial afterglow. Simulation results also suggest that, at the same flow velocity, larger particles obtain a greater magnitude of charge, negative or positive. The decrease in electron mobility and the difference between ion and electron convective loss rates create an ion-rich region in the plasma effluent that promotes ion–particle collisions and drives particle charge removal and even reversal of polarity. Larger particles more favorably collide with energetic species in these environments, which results in higher charge states.

Plasma Parameters around a Chain-Like Structure of Dust Particles in an External Electric Field

The formation of a 1D chain-like structure of dust particles in a low-temperature argon plasma was studied. A new numerical model for calculation of the self-consistent spatial distribution of plasma parameters around a chain of dust particles was presented. The model described the motion of positively charged ions in the electric potential of several negatively charged dust particles, taking into account the action of an external electric field. The main advantage of the model was that the charges of the dust particles and the interparticle distances were determined self-consistently. As a result of numerical simulations, the dependencies of the spatial distributions of the plasma parameters (the densities of electrons and ions and the self-consistent electric potential) near the dust particles chain on the strength of the external electric field, an external force acted on the last particle, and the mean free path of the ions was determined. The obtained results made it possible to describe the process of the formation of chain-like structures of dust particles in discharge plasma.

The influence of surface charge on the coalescence of ice and dust particles in the mesosphere and lower thermosphere

Abstract. Agglomeration of charged ice and dust particles in the mesosphere and lower thermosphere is studied using a classical electrostatic approach, which is extended to capture the induced polarisation of surface charge. Collision outcomes are predicted whilst varying the particle size, charge, dielectric constant, relative kinetic energy, collision geometry and the coefficient of restitution. In addition to Coulomb forces acting on particles of opposite charge, instances of attraction between particles of the same sign of charge are discussed. These attractive forces are governed by the polarisation of surface charge and can be strong at very small separation distances. In the mesosphere and lower thermosphere, these interactions could also contribute to the formation of stable aggregates and contamination of ice particles through collisions with meteoric smoke particles.

A fully nonlinear solitary wave in six-component dusty cometary plasma

The dynamics of fully nonlinear structure of six-component dusty cometary plasma system with the help of Sagdeev pseudo-potential techniques have been investigated. This plasma system is made up of Oxygen (positively and negatively charged) ion pair, negatively charged dust particles, and kappa distributed ions of Hydrogen, hot solar electrons and slightly colder cometary electrons. The linear analysis is carried out and the linear dispersion relation is obtained and investigated with some relevant plasma parameters. As a result, the velocities in the fluid equations are normalized to a general acoustic speed instead of the particular form of acoustic speed. Employing pseudo-potential approach, the basic equations of plasma system were reduced to a single nonlinear ordinary differential equation (energy-balance). By means of Sagdeev potential curves and bifurcation analysis of phase-portrait, the existence and propagation of nonlinear waves are examined. In addition to the periodic solution, it is shown that the localized negative and positive amplitude electrostatic pulses may (co-) exist and propagate in plasma system depending on the Mach number intervals. The impact of some intrinsic plasma parameters on the main features of the solitary wave electrostatic potential profile and the associated electrostatic field are extensively investigated. The results of this research are relevant to plasmas in both laboratory plasmas and exclusively in space plasmas as, comet tails, rings of giant planets, solar wind, interstellar clouds, etc.