Charged Dust Particles Research Articles

Global dust density in two-dimensional complex plasma

The driven-dissipative Langevin dynamics simulation is used to produce a two-dimensional (2D) dense cloud, which is composed of charged dust particles trapped in a quadratic potential. A 2D mesh grid is built to analyze the center-to-wall dust density. It is found that the local dust density in the outer region relative to that of the inner region is more nonuniform, being consistent with the feature of quadratic potential. The dependences of the global dust density on equilibrium temperature, particle size, confinement strength, and confinement shape are investigated. It is found that the particle size, the confinement strength, and the confinement shape strongly affect the global dust density, while the equilibrium temperature plays a minor effect on it. In the direction where there is a stronger confinement, the dust density gradient is bigger.

Modeling of Electrostatic and Contact Interaction between Low-Velocity Lunar Dust and Spacecraft

The accumulation of highly adhesive dust on spacecraft presents a serious issue to hinder long-term extravehicular activity and the establishment of a permanent station on lunar surface. In contrast to the immediate physical damage caused by hypervelocity (>1.0 km/s) impacts, this adhesion observed at low-velocity (0.01 to 100 m/s) collisions can more unobtrusively and mortally degenerate the performance of equipment. This paper proposes a theoretical model aimed at comprehensively analyzing the dynamics of adhesion and escape phenomena occurring during low-velocity impacts between charged dust particles and spacecrafts enveloped by a plasma sheath. The electrostatic force is modeled using the image multipole method, and contact force is calculated based on the adhesive–elastic–plastic theory. The results reveal that the implementation of a dielectric coating possessing both low permittivity and low interface energy can substantially reduce energy dissipation during collisions. However, the ultimate adhesion on the surface or escape from the sheath for low-velocity charged dust is dominated by the long-range electrostatic interaction rather than short-range contact interaction. Positively charged particles of smaller sizes demonstrate a greater propensity for surface adhesion in comparison to negatively charged particles of larger sizes. Counterintuitively, without additional dust removal techniques, modifying the properties of the dielectric coating does not effectively reduce the accumulation of dust, which can be merely accomplished by decreasing the spacecraft’s potential. The model presented in this study serves as a crucial step toward understanding the mechanism of lunar dust pollution.

Propagation characteristics of nonlinear dust acoustic solitary waves in complex plasma with nonthermal electrons and trapped ions

The propagation characteristics of nonlinear dust acoustic solitary waves in a complex plasma system with nonthermal electrons and trapped ions are investigate in this work. The nonlinear dispersion relation of dust acoustic waves is obtained by using the linear method, and the two-dimensional autonomous system governing the motion of nonlinear dust acoustic waves is derived by using the Sagdeev potential method. At the same time, the specific expression of the Sagdeev potential function is obtained based on the Sagdeev potential equation. The numerical simulations are used to analyze the phase portraits of the two-dimensional autonomous system, revealing the linear periodic wave orbits, nonlinear periodic wave orbits, and homoclinic orbits co-existing in the complex dusty plasma system with nonthermal electrons and trapped ions. Furthermore, from the variations of the Sagdeev potential function with different system parameters it follows that only the compressive solitary waves exist in this complex plasma system. The significant influences of various system parameters on the amplitude, width, and waveform of the nonlinear dust acoustic solitary wave in the complex plasma system are discussed in detail. The results demonstrate that the Mach number, the nonthermal electrons and trapped ions, undisturbed dust particle number density, temperature, and charge have important effects on the propagating characteristics of the nonlinear dust acoustic solitary waves in a complex plasma with nonthermal electrons and trapped ions.

Analysis of dust charge fluctuations with double-ionized ions and plasma oscillations / instabilities in Hall thrusters

In an electric propulsion system such as thruster, dust particles are generated because of the thrusters' wall erosion, and these heavily charged dust particles affect the thrusters' performance and life span. In this article, the charge and potential of a dust grain for various dust and plasma parameters are analyzed in a Hall thruster plasma having high electron thermal energy in the presence of double-ionized ions. The charging time of the dust is shown to be reduced with the increase in size while the charge on it increases. This has been observed that the dust grains' charging time and floating potential decrease when the density of double-ionized ions is increased. An increment in the floating potential is observed for higher plasma potential and electron temperature, but this increment occurs slower for higher electron temperatures. The floating potential doesn't change with the size of the dust in the plasma with zero fluctuations, but it depends on the dust grain size for fluctuating plasma parameters and the frequency of these fluctuations.

Size-dependent charging of dust particles in protoplanetary disks

Context.Lightning can have a profound impact on the chemistry of planetary atmospheres. In a similar manner, as protoplanetary disks are the foundation of planet formation, the emergence of lightning in protoplanetary disks can substantially alter their chemistry.Aims.We aim to study under which conditions lightning could emerge within protoplanetary disks.Methods.We employed the PRODIMOcode to make 2D thermo-chemical models of protoplanetary disks. We included a new way of how the code handles dust grains, which allows the consideration of dust grains of different sizes. We investigated the chemical composition, dust charging behavior, and charge balance of these models to determine which regions could be most sufficient for lightning.Results.We identify six regions within the disks where the charge balance is dominated by different radiation processes and find that the emergence of lightning is most probable in the lower and warmer regions of the midplane. This is due to the low electron abundance (nе/n〈H〉< 10−15) in these regions and dust grains being the most abundant negative charge carriers (nZ/n〈H〉> 10−13). We find that NH4+is the most abundant positive charge carrier in those regions at the same abundances as the dust grains. We developed a method of inducing electric fields via turbulence within this mix of dust grains and NH4+. The electric fields generated with this mechanism are however several orders of magnitude weaker than required to overcome the critical electric field.

Oblique Arbitrary Amplitude Dust Ion Acoustic Solitary Waves in Anisotropic Non-Maxwellian Plasmas with Kappa-Distributed Electrons

In this paper, we investigate the behavior of dust ion acoustic solitary waves (DIASWs) with arbitrary amplitudes in a magnetized anisotropic dusty plasma that includes inertial hot ion fluid, electrons following a Kappa distribution, and negatively charged dust particles in the background. An ambient magnetic field aligns with the x-direction, while the wave propagation occurs obliquely to the ambient magnetic field. In the linear regime, two distinct modes, namely fast and slow modes, are observed. We employ the Sagdeev pseudo-potential method to analyze the fundamental properties of arbitrary amplitude DIASWs. Additionally, we examine how various physical parameters influence the existence and characteristics of symmetric planar dust ion acoustic solitary structures (DIASs). The characteristics of the solitary structures are greatly influenced by the dust concentration, the electrons superthermality (spectral) index, the obliquity parameter, the magnetic field, the parallel ion pressure and the perpendicular ion pressure. The results show that the amplitude and width of both compressive and rarefactive DIASWs are sensitive to the degree of electron superthermality and dust concentration. Additionally, it is shown that the propagation features of DIASWs are highly affected by the parallel component of ion pressure as compared to perpendicular component of ion pressure.

Investigation of the Rayleigh–Taylor instability in charged fluids

The present study shows that the Rayleigh–Taylor (RT) instability and its growth rate are strongly dependent on the charge-mass ratio of charged particles in a charged fluid. A higher charge-mass ratio of the charged fluid appears to result in a stronger effect of the magnetic field to suppress the RT instability. We study the RT instabilities for both dusty plasma (small charge-mass ratio of charged particles) and ion-electron plasma (large charge-mass ratio of charged particles). It is found that the impact of the external magnetic field to suppress the RT instability for ion-electron plasma is much greater than that for dusty plasma. It is also shown that, for a dusty plasma, in addition to region parameters such as the external magnetic field, region length, its gradient, as well as dust particle parameters such as number density, mass, and charge of dust particles, the growth rate of the RT instability in a dusty plasma also depends on parameters of both electrons and ions such as the number densities and temperatures of both electrons and ions.

Combine influence of charged particles and dust particles in tri-cross hybrid nanomaterials on 3D surface via GFET

Nanoparticles are used in many industrial processes due to their wider applications. The current inspection deals the utilization of nanoparticles to boost thermal efficiency. This research reports the inclusion of nanoparticles and dust particles for the flow of tri-hybridized nanofluid with thermal transport in a stretchable porous sheet with Hall and Ion slip contribution. The mechanism of thermal transport is carried out by engaging the radiation and Joule heating effects and the flow-presenting equations are derived from the principle of boundary layer theory in Cartesian coordinates. The principle of boundary layer theory was engaged to derive momentum transport for tri-hybridized nanoparticles, dust particles and thermal transport in the presence of Joule heating and external heat sources. The derived equations are in the form of coupled PDEs (partial differential equations) for three-dimensional model which are converted into coupled ODEs (ordinary differential equations) and the simplified expressions are handled numerically via finite element procedure. The results are prepared for the solution in the form of tables and graphs against different involved parameters. The results reveal that thermal enhancement and motion of the particles for the case of the fluid phase are higher than the thermal enhancement and motion for the case of the dusty phase and additionally, thermal performance for the case of tri-hybrid nano-structures (SiO2-TiO2-Al2O3/engine oil) is higher than thermal performance for the cases of hybrid nano-fluid.

Magnetized dusty plasma: On issues of its complexity and magnetization of charged dust particles

AbstractIt is possible to excite various linear and nonlinear low‐frequency modes in dusty plasma, which is an admixture of electrons, ions, gas atoms, and negatively charged solid particles. The experimental as well as theoretical study of these low‐frequency dynamical modes in dusty plasma is very complex because of the involvement of dynamics of electrons, ions, and neutrals. If the external magnetic field is introduced to dusty plasma, then the dynamics of it will be more complex. The complexity of magnetized dusty plasma where plasma species (electrons and ions) are magnetized is discussed in detail by keeping the experimental findings in mind. The requirement of theoretical modeling, as well as computation experiments in understanding the dynamics of dusty plasma in the presence of a strong magnetic field, is suggested in the context of experimental findings. The major challenges to magnetizing the massive charged particles in plasma experiments and some proposed solutions are discussed in this review report.

Dynamical charging of interstellar dust particles in the heliosphere

Interstellar dust (ISD) particles penetrate the solar system due to the relative motion of the Sun and the local interstellar cloud. Before entering the heliosphere, they pass through the heliospheric interface – the region of the solar wind interaction with the interstellar plasma. The size distribution and number density of dust grains are modified in the interface essentially. The modification depends on the charging of the dust particles along their trajectories. In this paper, we present modeling results of the charging of ISD particles passing through the heliospheric interface. The main physical processes responsible for the charging within the heliospheric conditions are the sticking of primary plasma particles, secondary electron emission, photoemission, and the effects of cosmic ray electrons. We consider two methods to calculate the electric charge of ISD particles based on (1) the classic steady-state assumption that the charge depends only on local plasma and radiation conditions and (2) the dynamical computation of charge along the particle trajectory. We demonstrate that the steady-state assumption is quite justified to model trajectories and number density distributions of relatively big ISD grains (radius of 100 nm and larger) penetrating the heliosphere. The estimates show that ISD grains of these sizes require less than 0.25 years (distance of ≈1 au) after transition from the LISM into the heliosphere to reach an equilibrium. For small particles ( radius of 10 nm), the dynamical computation of charge influences the trajectories and modifies the number density substantially. The dust density accumulations are distributed within a more elongated region along the heliopause in case of dynamically changed charge as compared with the use of a steady-state charge approximation. As a result, the magnitudes of number density at the points of density features differ several times between the results obtained by the two considered approaches.

Electron–positron plasma in BBN: Damped-dynamic screening

We characterize in detail the dense e−e+γ plasma present during the Big-Bang Nucleosynthesis (BBN) and explore how it is perturbed electromagnetically by “impurities, i.e., spatially dispersed protons and light nuclei undergoing thermal motion. The internuclear electromagnetic screened potential is obtained (analytically) using the linear response approach, allowing for the dynamic motion of the electromagnetic field sources and the damping effects due to plasma component scattering. We discuss the limits of the linear response method and suggest additional work needed to improve BBN reaction rates in the primordial Universe. Our theoretical methods describing the potential between charged dust particles align with previous studies on planetary and space dusty plasma and could have a significant impact on the interpretation of standard cosmological model results.

On the stability of a charged rotating liquid droplet in plasma

The instability condition of a charged liquid dust particle (droplet) immersed in a plasma is considered theoretically. Both charging process and rotation effect are incorporated in the model. The dependence of the critical charge on the droplet radius is obtained for the regimes of fast and slow fragmentation.

Comparative Analysis of Terahertz Propagation Under Dust Storm Conditions on Mars and Earth

Reliable Terahertz (THz) links are necessary for outdoor point-to-point communication with the exponential growth of wireless data traffic. This study presents a modified Monte Carlo simulation procedure for estimating THz link attenuation due to multiple scattering by charged dust particles on the THz beam propagation path. Scattering models are developed for beams through dust, based on Mie and Rayleigh approximations for corresponding frequencies on Earth (0.24 THz) and Mars (0.24 & 1.64 THz). The simulation results are compared, considering parameters such as the number of Monte-Carlo photon (MCP) packets, visibility, dust particle placement density along the beam, frequency, and distance between the transmitter and the receiver. Moreover, a channel capacity model was proposed, considering THz link attenuation due to dust storms, spreading loss, and molecular absorption loss for Earth and Mars outdoor environments. Simulation results for Earth show that the link attenuation increases with dust particle placement density, distance, and frequency, and attenuation decreases with visibility and MCP packets. On Mars, similar results are obtained for both frequencies, except that the attenuation varies around a constant value with the frequency increase. Moreover, attenuation is slightly higher at 0.24 THz frequency compared to 1.64 THz when more dust particles are present on the beam propagation path. Channel capacity is estimated for Earth and Mars environments considering time and distance-dependent scenarios. Time windows that show a sudden drop of dust particles along the beam provide opportunities to communicate with high reliability. Moreover, increasing the distance between the transmitter and receiver severely reduces the channel capacity measurement in strong dust storm conditions in both environments. Our study has found that weak dust storms have relatively little effect on Mars but much more significant effects on Earth.

Role of electron temperature at extremely low density in negative positive ion plasma

It is pointed out that the role of electrons in the dynamics of pair ion and negative positive ion plasmas cannot be neglected even at extremely low density of electrons, i.e., ne0n+0≪mem+ (where nj0 is the background density of jth species and mj is the mass of the particles of the j-species while j = e, +, −) because electron thermal velocity is almost always larger than thermal velocities of ions, i.e., vT± ≪ vTe. An analysis of electrostatic waves in unmagnetized negative positive ion electron (NPIE) and pair ion electron (PIE) plasmas is presented for the case ωpe ≪ ωp+ (where ωpj=(4πnj0e2mj)1/2 is the plasma oscillation frequency corresponding to j-species). The electron dynamics contribute to electrostatic perturbations at ion plasma oscillation time scale at longer wavelengths for λDe2k2<1 where λDe=(Te4πne0)1/2 is the electron Debye length. On the other hand, the electron plasma wave turns into thermal wave when the conditions ωpe ≪ ωp± and 1≪λDe2k2 hold simultaneously and ion acoustic wave approaches the sum of ion plasma oscillation frequencies of positive and negative ions. The only electrostatic normal mode of such a plasma is the ion plasma wave corresponding to longer wavelengths, which also includes the contribution of electrons. The electron thermal wave is separated from plasma oscillations and electron time scale disappears with respect to electrostatic perturbations. Similar situation also occurs in plasmas having negatively charged dust particles. To elaborate these points, the analytical results are applied to the two experiments with NPIE and PIE plasmas.

Propagation of Nonlinear Dust-Acoustic Waves in a Self-Gravitating Collision Magnetized Dusty Plasma in Earth’s Magnetosphere

The nonlinear propagation of different types of DANW acoustic dust nonlinear waves has been investigated in a magnetized dusty plasma consisting of negatively charged dust particles, Maxwellian electrons, and ions. Application of the standard reductive perturbation theory is used to derive the corresponding three-dimensional nonlinear a complex Ginzburg–Landau (3D-CGLE) equation which governs the dynamics of the dust-acoustic wave packets. The stationary analytical solutions of the CGLE are numerically analysed where the effect of the physical parameters of the dusty plasma model on the wave’s propagation is taken into account. It has been found that there can be a relationship between the appearance of soliton waves and electromagnetic waves, as well as between shock-like waves and periodic travelling waves. Expression of the importance of these findings is the cornerstone of explaining the true relationship between the propagation of nonlinear waves in the physics of space, for example, the Earth’s magnetic field.

Dynamics of dust and meteoroids due to electromagnetic transport in the heliosphere

ABSTRACT Observations of dust in the Solar system have indicated the existence of structures at higher ecliptic latitudes, the origin of which is still an ongoing debate. In a previous study, we studied how the interplanetary magnetic field affects the orbital motion of charged dust particles that are moving in co-orbital motion with Jupiter. Our findings revealed that the Lorentz force causes oscillations in orbital inclinations that lead to electromagnetic transport of the dust particles to higher ecliptic latitudes. In this work, using numerical simulations, we investigate how this transportation depends on orbital lifetime, strength of the background magnetic field, planetary mass, and distance from the Sun. In addition, we study the dynamics also outside resonance. We present our findings using the saturation curve, which gives a relation between the maximum amplitude in inclination with respect to the particle size ranging from 1 to 501 $\mu$m. We further study the influence of the solar radiation pressure, the Poynting–Robertson, and the solar wind effects on the shape of the saturation curve and find that a stronger gravitational influence of the planet leads to a steeper curve, decreasing the strength of the electromagnetic transport. The radiative forces lead to a gradual dampening of the latitudinal oscillations of particles inside resonance, while they are unchanged for objects outside of resonance. We argue that the dynamics of dust and meteoroids in the Solar system can only be understood by including space weathering effects.

Photoelectric charging of dust inprotoplanetary disks

The process of ionization-recombination of gas and charging of dust particles under the action of X-rays under space plasma conditions is considered. The conditions are found when, as a result of exposure to radiation, dust particles in a protoplanetary disk can acquire a positive charge even with low gas ionization.

Controlling the charge of dust particles in a plasma afterglow by timed switching of an electrode voltage

A method is demonstrated for controlling the charge of a dust particle in a plasma afterglow, allowing a wider range of outcomes than an earlier method. As in the earlier method, the dust particles are located near an electrode that has a DC voltage during the afterglow. Here, that DC voltage is switched to a positive value at a specified delay time, instead of maintaining a constant negative voltage as in the earlier method. Adjusting the timing of this switching allows one to control the residual charge gradually over a wide range that includes both negative and positive values of charge. For comparison, only positive residual charges were attained in the earlier method. We were able to adjust the residual charge from about −2000 e to +10 000 e, for our experimental parameters (8.35 µm particles, 8 mTorr argon pressure, and a DC voltage that was switched from −150 V to +125 V within the first two milliseconds of the afterglow). The plasma conditions near the dust particles changed from ion-rich to electron-rich, when the electrode was switched from cathodic to anodic. Making this change at a specified time, as the electrons and ions decay in the afterglow, provides this control capability. These results also give insight into the time development of a dust particle’s charge in the afterglow, on a sub-millisecond time scale.

Dust acoustic solitary waves in dusty plasma with nonuniform temperature

In this paper, the dust acoustic wave is studied in conditions where the dust temperature is not constant. This model includes negatively charged dust particles and thermal ions. The reductive perturbation technique is used and the new point in this study is the nonuniformity of the plasma temperature. The nonconstancy of the temperature is entered as a first-order perturbation in the calculations, and finally the modified Korteweg–de Vries (mKdV) equation is derived. The solution of the modified KdV equation clarifies the change in soliton shape of the wave when it moves in the perturbation plasma. We show how the soliton wave undergoes deformation and amplitude reduction during propagation when it encounters a region with a different temperature. The output of this research can be effective to better understand the wave behavior in a real plasma with nonuniform temperature.

Temporal afterglow between two pulses of repetitively pulsed argon-acetylene plasma: measuring electron and negatively charged species densities

The temporal afterglow between two pulses of a repetitively pulsed radio-frequency driven low-pressure argon-acetylene plasma is experimentally explored using laser-induced photodetachment combined with microwave cavity resonance spectroscopy. The densities of electrons and negatively charged species, i.e. anions and dust particles, are measured temporally resolved until 1.9 s in the temporal plasma afterglow. Two different plasma-on times are adjusted to investigate the dynamics of anions and dust particles in the afterglow phase. The measurements show that while electrons decay rapidly within the first few milliseconds of the afterglow phase, the negatively charged species reside much longer in the plasma after the plasma is switched off. The electron density decay is measured to be faster for a longer plasma-on time. This effect is attributed to an enhanced recombination rate due to a higher dust particle density and/or size. The density of negatively charged species decays within two different timescales. The first 20 milliseconds of the afterglow is marked with a rapid decay in the negatively charged species density, in contrast with their slow density decay in the second time scale. Moreover, a residual of the negatively charged species densities is detected as long as 1.9 s after extinguishing the plasma.