Charged Dust Particles Research Articles

COMPLEX TECHNOLOGY OF THE CLEANING OF AGGLOMERATION GASES FROM DUST AND HARMFUL GASES WITH OBTAINING A GOOD PRODUCT

The purpose of the work is to improve the design of the dust-catching device of the sintering machine, to increase the efficiency of catching charged dust particles in laminar layers near the precipitating elements, the configuration and location of the elements of the precipitating elements, to establish the dependence of the effective (calculated) drift speed of charged dispersed particles on the speed of the medium being cleaned, with classical the process of electrogas purification and the combined flow of gases in electrofilters. It was established that the combined movement of gases in a modular unit ensures the charging of the entire population of dust particles to the limit values ​​by organizing a highly turbulent flow and keeping dust particles in the zones with the greatest tension in the corona charge covers, as well as effective trapping of charged dust particles in laminar layers near the precipitating elements . Mathematical modeling of the deposition block was carried out in order to optimize the configuration. The main dependences of the number and mutual location of precipitating elements to ensure maximum dust deposition were established. Studies of gas medium velocity spectra in models of new electrostatic precipitators have been carried out. The optimal live cross-sections of the aerodynamic partitions are determined to ensure favorable conditions for charging suspended particles and uniform distribution of the cleaned flow through the catching holes. The MV-2 modular type electric gas purification device with a capacity of 30 thousand nm3/h has been developed, based on innovative developments in the field of KEIT (combined electro-ion gas purification technology) in the field of conversion and control of cascade energy and aerodynamics of turbulent and laminar flows during inertial deposition dispersed suspension of flue gases. An apparatus for cleaning gases from a sinter machine with a capacity of up to 400,000 nm3/h is proposed. with an efficiency of 99 %, for replacing existing equipment (multicyclones). "MV-2JS" electric device was developed. This is a plasma-catalytic reactor, which allows you to produce the necessary amount of ozone in a low-cost way to oxidize the harmful components (SO2, NOx, CO) of the outgoing gases. The use of this device allows, in addition to the cleaning of flue gases from harmful gas impurities, to obtain commercial products (fertilizers, gypsum, sulfuric acid, etc.) at the output and to completely get rid of solid and liquid waste during gas desulfurization.

Self‐Organization of Relaxed Structures in the Lunar Atmosphere

ABSTRACTThe study investigates the relaxation of a three‐component dusty plasma in the lunar atmosphere. By employing Ampère's law with momentum balance equation of the plasma species, which includes an electron, a positive ion, and a negatively charged dust particle, a Triple Beltrami (TB) state is obtained. This TB state is characterized by three scale parameters, which may be real or complex. The Cartesian coordinate geometry is employed to analyze the magnetic field profiles. The Beltrami parameters, mass of negative charged dust particulates and density variations at different height and angle have a significant impact on the magnetic properties of the self‐organized structures in lunar atmosphere. The study reveals that all scale parameters associated with diamagnetic structures are real and complex, while all scale parameters for paramagnetic structures are real. It has been shown that the magnetic field, along with its complex conjugate and real part, increases with height and angle, and only diamagnetic structures are formed in the lunar atmosphere. The findings of this study should help to explain relaxed structures found in other astronomical objects and in lab settings including negatively charged dust particles, ions, and electrons.

Design of the electrode structure for the dust removal efficiency optimization of electrostatic precipitator

Abstract Air dust pollution prevention and control is a global environmental concern. Electrostatic precipitators (ESPs) play a crucial role in dust pollution control, and its electrode structure significantly affects plasma parameters and the movement of charged dust particles, which in turn influences the dust removal efficiency. This study focuses on optimizing the commonly used wire-plate dust removal device, experimental research is conducted first, revealing that the hole-hole electrode structure of an ESP exhibits higher peak currents at the same voltage compared to both plate-hole and plate-plate electrode configurations. For the removal efficiency of particles with a radius greater than 1 μm, the ESP with a hole-hole electrode structure performs better than those with plate-hole and plate-plate electrode structures. Moreover, the particle collection efficiency is positively correlated with particle radius, larger particles correspond to higher dust removal efficiency. Based on experimental findings, simulations are conducted to provide a deeper analysis and understanding of the dust removal mechanisms of ESPs. This paper primarily utilizes COMSOL Multiphysics numerical simulation software to simulate traditional wire-plate ESPs and a new wire-hole ESP. It explores the multiphysical characteristics of ESPs under different electrode structure configurations, and investigates in depth the impact of electrode structure on dust removal efficiency. The simulation results indicate that compared to flat collecting electrodes, porous collecting electrodes exhibit a significant increase in electric field intensity at the openings, and they have a lower surface charge density than flat plates, thereby reducing reverse corona phenomena. Ion wind affects the internal airflow dynamics of ESPs, thereby influencing their efficiency in capturing fine particulate matter. This negative impact of ion wind can be mitigated by introducing perforations in the collection plates.

Depinning and evolution of charged dust particles in the presence of external force

Depinning and evolution of charged dust particles in the presence of external force

Aluminum dust concentration detection based on LSTM-Kalman filter

Industrial dust emissions present serious hazards, including respiratory issues and explosion risks. Traditional dust concentration detection methods are often compromised by environmental factors. This study introduces a novel FFT-KF-LSTM-NET model to predict high-concentration aluminum powder levels, utilizing 128 sets of electrostatic induction measurement data. By applying the Fast Fourier Transform (FFT) to eliminate low-frequency interference, integrating Long Short-Term Memory (LSTM) networks for advanced time series analysis, and using the Kalman Filter (KF) for rapid model convergence, this approach significantly enhances prediction accuracy. The model achieves an 82% improvement in Mean Squared Error (MSE), reducing it to 0.1336, outperforming traditional methods. Furthermore, by modeling the voltage signal generated by charged dust particles in the electrostatic induction sensor's sensing area and using the first derivative of the voltage signal as a learning feature, the model's prediction speed is increased from 1.5 s-2 s–0.5 s, with improved anti-interference capabilities. These advancements position the FFT-KF-LSTM-NET model as a crucial tool for real-time, reliable dust concentration detection in industrial environments.

On Anomalous Dissipation in Plasma of Dusty Mercury’s Exosphere

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

Dynamical generation of macroscale magnetic fields and fast flows in a four-component astrophysical plasma

We explore the possibility of the generation or amplification of macroscale magnetic fields and flows in a four-component astrophysical dusty plasma composed of mobile massless electrons and positrons, inertial positive ions and negatively charged static dust particles. The investigation demonstrates that when microscopic turbulent ambient plasma energy is predominantly kinetic, a straight dynamo (DY) mechanism is feasible. Conversely, a unified reverse-dynamo/dynamo (RDY/DY) mechanism is possible when the microscopic turbulent ambient plasma energy is primarily magnetic. Additionally, the evolution of Alfvén Mach numbers at the macro- and microscale are significantly affected by plasma species densities and invariant helicities. The potential implications of the present study for astrophysical settings are also highlighted.

Role of Cairns–Gurevich ion distribution on nonlinear wave propagation in negatively charged dusty plasma

The study of dust-acoustic (DA) nonlinear electrostatic waves in dusty plasma is crucial for understanding plasma behavior in both astrophysical and laboratory environments. Dusty plasmas, characterized by the presence of negatively charged dust particles, exhibit complex dynamics influenced by various factors, including nonthermal electron and ion populations following Cairns–Gurevich distributions. This study addresses the problem of understanding wave propagation under these specific conditions by employing a set of fluid hydrodynamic equations for dust fluid, alongside appropriate electron and Cairns–Gurevich ion distributions, to model the dynamics and propagation of DA nonlinear electrostatic waves under specific plasma conditions with negatively charged dust particles. We derived a nonlinear Zakharov–Kuznetsov (ZK) equation to model the evolution of these waves and further transformed it into the nonlinear Schrödinger (NLS) equation to analyze rogue wave formation and identify unstable and stable zones within the plasma. We focused our analysis on the effects of key parameters, such as the nonthermal index, magnetic field strength, negative dust temperature ratio, polarization force, and density ratio, on the behavior of dust-acoustic waves (DAWs). The results demonstrated that soliton waves, explosive waves, and kink waves exhibit distinct behaviors depending on these parameters and the spatial context of Earth's magnetosphere. These findings provide new insights compared to previous studies into the conditions under which these waveforms emerge and evolve, especially in magnetized environments where earlier models were less effective at accurately characterizing or predicting wave behavior. By applying two different analytical methods, a direct integration approach and a generalized Kudryashov method, we expanded our understanding of nonlinear wave phenomena in dusty plasmas. Our results not only advance theoretical knowledge but also have practical implications for interpreting space plasma observations and guiding experimental design in plasma physics research. This study thus contributes to a more comprehensive understanding of plasma dynamics, with potential applications to astrophysical observation and laboratory plasma experimentation.

Charging and Mobilization of Dust Particles on a Surface in Plasma.

We present first experimental results showing that single dust particles on a dielectric surface are mobilized and lofted due to exposure to an electron beam or ultraviolet radiation. It is shown that secondary electrons and/or photoelectrons emitted from a substrate surface are recollected on the surfaces within microcavities between a dust particle and the substrate surface, resulting in large negative charges and subsequently causing mobilization of the dust particle due to Coulomb repulsion. Dust mobility tested against the electron beam energy is shown to follow the secondary electron yield curve of the substrate surface in both the experimental and modeling results. The results verified the role of emitted electrons from the substrate surface in charging and mobilization of single dust particles.

Zakharov–Kuznetsov Equation for Describing Low-Frequency Nonlinear Dust Acoustic Perturbations in Saturn’s Dusty Magnetosphere

A description is given of low-frequency nonlinear dust acoustic waves in Saturn’s dusty magnetosphere, which contains electrons of two types (hot and cold) obeying the kappa distribution, magnetospheric ions, and charged dust particles. For the corresponding conditions, the derivation of the Zakharov–Kuznetsov equation is given, which describes the nonlinear dynamics of dust acoustic waves in the case of low frequencies and a pancake-shaped wave packet along an external magnetic field. It is shown that under the conditions of Saturn’s magnetosphere there exist solutions of the Zakharov–Kuznetsov equation in the form of one-dimensional and three-dimensional solitons. Possible observations of the considered solitons in future space missions are discussed.

Symmetrical vortices and laminar dust flow induced by an intense electron beam interacting with a strongly coupled dusty plasma

A strongly coupled quasi-two-dimensional dusty plasma confined electrostatically in the plasma sheath of a radio frequency (RF) plasma is irradiated by a collimated and mono-energetic pulsed electron beam (e-beam) with an energy of 13 keV and a high peak current per pulse of 30 mA. A stream of rapidly moving charged dust particles is created inside the dust crystal due to the drag force of the electrons in the e-beam. The dust flow is split into two symmetrical branches when it reaches the boundary of the round dust crystal, each following the limit of the circular confining region. This results in the formation of a double vortex flow pattern with the dust particles being transported along the irradiation direction and then aside, eventually back to the entrance position of the e-beam. The observed flow regime is laminar at all times, with the speed in the central region increasing up to 12 mm s−1 in the first 200 ms and then diminishing gradually to a steady value of about 5–6 mm s−1 during a stress relaxation time period of 360 ms. The vorticity follows a similar trend with peak values −3.8 and 3.8 s−1 and steady state values between −2.5 and 2.5 s−1 in the two symmetrical vortices. Time-resolved particle-image-velocimetry and particle-tracking-velocimetry are used to characterize the flow. Molecular dynamics simulations confirm qualitatively the experimental observations showing dust stream and double vortex formation.

Dust particle surface potential in an argon-helium plasma using the (r,q)-distribution function

Abstract In this paper, the dust particle surface potential for argon-helium plasma is evaluated analytically and numerically in the context of negatively charged dust particles by employing a power-law r , q -distribution function. Recent studies have reported the argon-helium plasma and conducted a brief theoretical and experimental survey. To deepen our understanding further, this study aims to analyze the argon-helium plasma comprehensively using the same pattern but with the r , q -distribution function. For this purpose, the current balance equations are derived for electron, helium and argon ions, when these charge species attain the quasineutrality condition. We numerically examined the currents of plasma species for a broad range of effective distribution function parameters r and q . It is revealed that the surface potential of dust particles is significantly affected by the parameters r and q , helium ion-to-electron temperature ratio, argon ion-to-electron temperature ratio, and helium ion to argon ion number density ratio. By incorporating the multi-ion (argon-helium) species, the significance of low-temperature non-Maxwellian dusty (complex) plasma is briefly examined.

The effect of the electron κ-distribution on the dust particle charging in the radio-frequency thermal-sheaths

In order to investigate collisionless radiofrequency plasma sheaths containing dust particles, three models are utilized: the novel kinetic scheme Ensemble-in-Spacetime (EST) model for calculating sheath parameters, the Dust Particle Charging model, and the Single Dust Particle model. The EST model has been modified to account for κ-electron distributions. This model is applicable to radiofrequency plasma sheaths found in tokamaks equipped with an ion cyclotron radiofrequency (ICRF) wave heating system, such as JET, West(Tore Supra), EAST, ASDEX-U, and KSTAR. The calculated sheath parameters are utilized to determine the electron and ion currents of the dust particles. In the intermediate radio-frequency regime, when the ion plasma frequency is comparable to the ICRF, the flux and energy of the ions are modulated in time within the sheath. The ions are not inertialess, and the value of κ affects the electron and ion densities. As the value of κ increases, the time-averaged electron and ion densities, sheath edge position, and area of the sheath voltage-sheath charge hysteresis loop also increase. However, the ion energy distribution remains insensitive to the κ distribution. The dust particles are charged with different negative charges based on their radius, position within the sheath, κ-electron distribution, and sheath potential. These particles exhibit oscillatory motion due to their interactions with the plasma and gravitational fields and are accelerated toward the plasma core.

Photoelectric charging and lofting of dust particles on a conducting surface with external electric fields

We present a laboratory study of photoelectric charging of dust particles and their lofting on a conducting surface in the presence of external electric fields. Insulating particles with diameter <45 μm are dispersed on a conducting surface exposed to ultraviolet (UV) light. In addition to the UV exposure, a positive or negative external electric field is applied. Independent of the orientation of the external electric field, the dust particles are found to be positively charged but with different mechanisms. It is shown that the orientation of the external electric field controls the dynamics of photoelectrons emitted from the dust particles and the conducting substrate surface. Distinctly different lofting results are shown between these two electric field cases. The results provide insight for understanding dust charging and release and helping develop mitigation solutions in particle accelerators, semiconductor manufacturing, fusion reactors, and space exploration to planetary bodies.

Complex shock structure in multi-species dusty plasma with nonextensive electrons and two-temperature nonthermal ions

A theoretical investigation has been made to explore the behavior of nonplanar (cylindrical and spherical) electrostatic shock waves in a dusty plasma system that consists of arbitarily charged dust particles, negatively charged heavy ions following Cairn’s distribution, positively charged ions with two different temperatures, and nonextensive electrons. The reductive perturbation technique is used to derive a modified Burgers equation analytically. Analytical analysis shows that the characteristics of the nonplanar shock waves, including their polarity, amplitude, width, and phase speed, undergo significant alterations due to factors such as the charges on dust particles, the number density of particles, the temperatures of heavy and light ions, nonextensive electron behavior, and dust kinematic viscosity. Furthermore, this study found shock structures with either a positive or negative potential, depending on the critical value of the proportion of ions to the density of dust particles. The findings maybe useful in understanding the characteristics of shock waves both in space plasma environments and laboratory plasmas.

Parameters of dust particle chains levitated vertically in a gas discharge plasma

The structural parameters of the dust particle chains suspended vertically in the electric field of a gas discharge are studied here. The investigations are performed by a numerical multi-block model based on a mean field approximation. The model describes the movement of ions and dust particles under the action of an external electric field, the electric field (Coulomb) of each charged dust particle, and the field of bulk plasma charge (ions and electrons) that screens the charges of dust particles. The gravity and the ion drag forces acting on the dust particles are also taken into account. Self-consistent chain parameters are calculated and compared for different number (1, 3, 5, and 7) and two different diameters (3.4 and 8.94 mcm) of dust particles in the chains. It is shown that an “ion wake” is formed behind the dust structures, and it grows with the number of dust particles and their size. With an increase in the number of dust particles in the chain, the charge of the first (top) dust particle increases. In the case of small dust particles, with an addition of new particles into the chain, the centers of the chains almost remain at the position of a single particle in the vertical direction. The chains of big dust particles move as a whole down in the direction of gravity with an increase in the number of particles.

Experimental modeling of atmospheric discharge phenomena and charged dust particle interactions

Experimental modeling of atmospheric discharge phenomena and charged dust particle interactions

Effect of Multi-Frequency Excitation on Dust Particle Charging in Weakly Collisional Radio-Frequency Capacitive Discharge

Effect of Multi-Frequency Excitation on Dust Particle Charging in Weakly Collisional Radio-Frequency Capacitive Discharge

Role of polarized force on dust-acoustic structures in the presence of suprathermal electrons

The modulational instability (MI) of dust-acoustic wave (DAW) in an unmagnetized dusty plasma including dust, ions, and electrons is studied. Electrons are kappa-distributed, ions follow a Maxwellian distribution, and negatively charged dust particles display dynamic behavior. A nonlinear Schrödinger equation (NLSE) is generated using the Krylov–Bogoliubov–Mitropolsky approach to explore MI. Using the essential physical characteristics, the steady and unstable portions of the modulated wave packets are properly characterized. The impact of polarization force, suprathermal index (κ), effective temperature of electron to ion temperature ratios, and other physical factors in stable and unstable DAW zones is numerically studied. In unstable zones, unpredictable amplitude perturbations cause freak/rogue waves for which the essential studies on the localized solutions of the NLSE are done extensively.

The influence of an externally applied electric field on residual microparticle charge in a spatio-temporal afterglow plasma

The residual charge of dust particles in spatial and temporal afterglow plasmas is relevant in many fundamental research fields and technological applications. It has been shown in both spatial and temporal afterglow plasmas that the presence of an externally applied electric field can greatly influence the residual dust particle charge. However, this has not yet been explored in a combined spatiotemporal afterglow plasma. In this work, the influence of an externally applied electric field on the residual microparticle charge is, therefore, investigated in a spatiotemporal afterglow plasma. It is found that the measured charge is predominantly affected by changes to the spatial component of the spatiotemporal afterglow when an electric field is applied, while the influence on the temporal component seems to be significantly less relevant. Our results contribute to an improved understanding of particle (de-)charging in afterglow plasmas and are highly relevant to the design of applications in which afterglow plasmas are present and where the charge of dust particles needs to be controlled for the sake of (nano)contamination control.