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In this paper, the Crank-Nicholson method is applied to solve the one-dimensional nonlinear Burgers' equation in warm, dusty plasmas with dust charge variation. After obtaining numerical results, a thorough analysis is conducted and compared against analytical solutions. On the basis of the comparison, it is evident that the numerical results obtained from the analysis are in good agreement with the analytical solution. The error between the analytical and numerical solutions of the Burgers' equation is calculated by two error norms, namely L2 and L∞. A Von-Neumann stability analysis is performed on the present method, and it is found to be unconditionally stable according to the Von-Neumann analysis. [ABSTRACT FROM AUTHOR]

Melamine formaldehyde microspheres are widely used in dusty plasma experiments for their monodispersity, sphericity, low mass density, and well defined sizes. This paper summarizes problems that were encountered in numerous applications of these grains in different laboratory simulations. and the already published results are discussed in view of new experiments. The main results of this paper are connected with changes of the grain mass due to the decreased pressure and/or increased temperature and variations of the grain dimensions, its shape, and mass density under electron or ion bombardments. By contrast to the work function estimated from field emission properties, we have found the photoelectric work function (4.5 eV) being close to that expected. A sputtering of the grains using a 30-keV ion beam revealed their unexpected heterogeneity. [ABSTRACT FROM AUTHOR]

This paper discusses the newly discovered acoustic waves that arise from the equilibrium between the inertia of dust particles and plasma pressure. The propagation of these waves is demonstrated to be non-linear, with supersonic solitons exhibiting either a positive or negative electrostatic potential, and linear, with normal modes in a dusty plasma. Implementing the unified method and the generalized projective Ricatti equation technique, we generate a variety of optical wave structures for the governing framework. Using 3 D and 2 D dimensional illustrations, the fundamental behavior of the derived solutions is visually analyzed by choosing appropriate values for arbitrary parameters that satisfy the specified constraints. The employed methodologies are acknowledged to be a powerful and effective mechanism for creating solitary wave solutions for non-linear evolution models. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Applicability limit of the well-known phase diagram of dusty plasmas in κ-Γ plane (κ is structural parameter and κ is parameter of Coulomb nonideality) is under discussion. Existence of extensive domains with violation of plasma thermodynamic stability conditions (i.e., with negative isothermal compressibility) was also claimed if one uses well-known nonideal equations of state by (Hamaguchi S. et al., Phys. Rev. E, 1997) and (Khrapak S. et al., Phys. Rev. E, 2014). This paper is devoted to analysis of a range of applicability for basic assumption in Hamaguchi's phase diagram, i.e., linearized (Debye) screening of macroions by microions, which leads to the Yukawa form for effective interactions between macroions. Parameters of nonlinear screening for macroions were calculated within differential Poisson--Boltzmann equation. Two effects were revealed as a result of such calculations: 1) decomposition of all microions onto two subclasses, free and bound ones, and 2) significant reduction of effective charge Z* of initial bare macroion Z under nonlinear screening by small high-density envelope of bound ions. This effect leads to a renormalization of initial Γ and κ into Γ* and κ* (Γ* < Γ, κ* < κ). The main physical assumption is phase states of complex plasma under nonlinear screening, which are still the same as on the initial phase diagram, but in κ*-Γ* plane instead of κ-Γ one. Corresponding calculated shifts of phase states are discussed and illustrated. [ABSTRACT FROM AUTHOR]

Aiming to delineate the physical framework of blazars, we present an effective method to estimate four important parameters based on the idea proposed by Becker & Kafatos, including the upper limit of central black hole mass M, the Doppler factor δ, the distance along the axis to the site of the Îł -ray production d (which then can be transformed into the location of Îł -ray-emitting region R Îł ) and the propagation angle with respect to the axis of the accretion disk Φ. To do so, we adopt an identical sample with 809 Fermi-LAT-detected blazars which had been compiled in Pei et al. These four derived parameters stepping onto the stage may shed new light on our knowledge regarding Îł -ray blazars. With regard to the paper of Becker & Kafatos, we obtain several new perspectives, mainly in (1) putting forward an updated demarcation between BL Lacs and FSRQs based on the relation between broad-line region luminosity and disk luminosity both measured in Eddington units, i.e., L disk/ L Edd = 4.68 Ă— 10âˆ'3, indicating that there are some differences between BL Lacs and FSRQs on the accretion power in the disk; (2) proposing that there is a so-called “appareling zone,” a potential transition field between BL Lacs and FSRQs where the changing-look blazars perhaps reside; (3) the location of Îł -ray emission region is principally constrained outside the broad-line region, and for some BL Lacs are also away from the dusty molecular torus, which means the importance of emission components in the jet. [ABSTRACT FROM AUTHOR]

Cellulose is an abundant natural polymer and is thus promising for enforcing biobased plastics. A broader application of cellulose fibers as a filler in polymer composites is limited because of their hydrophilicity and hygroscopicity. The recent scientific literature on plasma methods for the hydrophobization of cellulose materials is reviewed and critically evaluated. All authors focused on the application of plasmas sustained in fluorine or silicon-containing gases, particularly tetrafluoromethane, and hexamethyldisiloxane. The cellulose materials should be pre-treated with another plasma (typically oxygen) for better adhesion of the silicon-containing hydrophobic coating. In contrast, deposition of fluorine-containing coatings does not require pre-treatment, which is explained by mild etching of the cellulose upon treatment with F atoms and ions. The discrepancy between the results reported by different authors is explained by details in the gas phase and surface kinetics, including the heating of samples due to exothermic surface reactions, desorption of water vapor, competition between etching and deposition, the influence of plasma radiation, and formation of dusty plasma. Scientific and technological challenges are highlighted, and the directions for further research are provided. [ABSTRACT FROM AUTHOR]

This paper presents the results of a recent study of the interaction between charged dust particles and plasma ions through the electrostatic and ion drag forces in a dc glow discharge plasma. Measurements of the dust particles motion are carried out using particle image velocimetry (PIV). When an electrostatic perturbation is applied to the dust cloud, the particle motion, in response to the perturbation, is shown to reverse direction as the gas pressure is increased. An analysis of the dust particle motion and background plasma parameters suggests that there is a change in the equilibrium position and competition between the electrostatic force and the ion drag force on the particles that lead to the asymmetric motion of the cloud. The ion drag and electric forces on the dust particles are calculated at each pressure using detailed measurements of the plasma parameters, as measured by a single Langmuir probe. The analysis of these measurements suggests that the reversal of direction is a result of the change in the electric field in the plasma, but that the effectiveness of the perturbation at displacing the dust cloud is controlled by the ion drag force. [ABSTRACT FROM PUBLISHER]

Dispersion is one of the important characteristics of dusty plasma. In this paper, the real and imaginary parts of the complex refractive index of dusty plasma are first deduced and verified by the Kramers–Kronig dispersion relation. And then, the dependence of dispersion ability on the temperature, pressure, angular frequency of incident electromagnetic wave, as well as the number density, radius, and charge of dust particles is given. Finally, the theoretical results indicate that: 1) the dispersion ability decreases with the increase of angular frequency; 2) the dispersion ability monotonically varies with the pressure approximately, but nonmonotonically varies with the temperature; and 3) the dispersion ability monotonically increases with the increase of dust particle’s charge, but nonmonotonically changes with the number density and radius of dust particles. In particular, the involved physical explanations are proposed. [ABSTRACT FROM AUTHOR]

This paper reports the levitation of micro-organisms in the sheath of radio-frequency (RF) plasma. Based on simple force-balance calculations, the required electric field for the levitation of micro-organisms has been estimated. It is predicted that micro-organisms could levitate at the periphery of the sheath. Experimental results demonstrate the levitation of two species of bacillus micro-organisms Escherichia coli (E. coli) and Klebsiella pneumoniae in an RF plasma. The almost monodiverse Klebsiella pneumoniae levitating in the RF plasma formed an ordered state similar to a 2-D Coulomb crystal. Diverse E. coli particles demonstrate the tendency that the levitating height of micro-organisms decreases as the radius of particles increases. Levitating micro-organisms in plasmas can be referred as dusty plasmas. [ABSTRACT FROM AUTHOR]

In dusty plasmas, dust particles are levitated by balance of forces inward to the plasmas (typically corresponding to electrostatic force) and outward from the plasmas (ion drag force) as well as gravity. The balance of the forces tends to make a region free from dust particles, so-called void at the center of the plasmas. This paper made it clear in measurements of ion density and electron temperature with a double-probe method that the void was a region involving ionization. The dust particles were distributed in the other region diffusion dominant for electrons and ions. The void is shown to be reduced by restricting the region involving ionization. [ABSTRACT FROM AUTHOR]

This special Issue focuses on the field of dusty plasmas or also referred to as complex plasmas. Most of the papers were presented at the 8th International Conference on the Physics of Dusty Plasmas (8 ICPDP, ), which was hosted by Charles University and held in Prague, Czech Republic, on May 20–25, 2017. We would like to join the continuous tradition of special issues of the IEEE Transactions on Plasma Science from April 1994, 2001, 2004, 2007, 2010, 2013, and 2016 associated with the other most important triennial meeting for the community, the Workshop on the Physics of Dusty Plasmas. We believe that these two conferences and papers connected to them reflect the current state of the art and progress in the field. [ABSTRACT FROM AUTHOR]

This paper presents a new approach to determining the dimensions of particles that can be lifted to a coma by the sublimation flux of water ice. Due to the diverse colour of the cometary surfaces, in the presented calculations we take into account the influence of the reflectance coefficient (hemispherical albedo) on the size of particles lifted from the surface of the nucleus. A Cary 5000 spectrometer was used to measure hemispherical albedo. Spectroscopic measurements used dust particles that consisted of pure silicate or were a mixture of pure silicate and organic compounds such as charcoal, soot, and ash. In addition, these admixtures acted as a means of darkening the tested sample. Depending on the colour of the sample and the wavelength, the measured value of hemispherical albedo oscillated in the range from 4.93 per cent to 48.65 per cent. A thermodynamic model of cometary matter emission was developed based on the results of hemispherical albedo measurements. The performed numerical simulations show that the temperature decreases with the increase of the hemispherical albedo, which translates into the sublimation flux and the dynamics of the dust-ice particles present on the surface of the cometary nucleus. Taking into account the extreme values of the hemispherical albedo, the differences in the size of particles carried away from the surface of the nucleus are in the order of centimeters. [ABSTRACT FROM AUTHOR]

In this paper, we have presented our investigation on the characteristic of nonlinear dust acoustic waves (DAWs) propagating in an inhomogeneous collisionless magnetized dusty plasma (MDP). In this problem, we have considered a collisionless plasma consisting of nonthermal ions, non-extensive electrons and negatively charged dust grains. Using the reductive perturbation theory (RPT) we have derived the modified Zakharov-Kuznetsov (m-ZK) equation. The solution of m-ZK equation indicates the nonlinear characteristics of the DASWs in plasma. Our investigation also predicts how the amplitudes of nonlinear DASWs are significantly modified due to the influence of magnetic field, non-extensive electrons and inhomogeneity parameters in plasma. The results obtained in this investigation may be useful for understanding the propagation characteristics and modification of structures of nonlinear waves in both laboratory and astrophysical plasmas. [ABSTRACT FROM AUTHOR]

This paper presents the results of experimental and numerical investigation of the influence of dust nanoparticles on glow discharge plasma properties. A special apparatus was developed to provide a steady input of dust nanoparticles into ac glow discharge plasma. The plasma was created in a large-volume coaxial gridded hollow cathode. A novel simulation approach of dusty plasma was developed specifically for the experimental conditions. An extended fluid approach with drift-diffusion approximation for the electron and ion fluxes was modified to account for charged dust nanoparticles’ contribution to net charge and for ion and electron loss on the surface of particles. Uniform distribution of dust particles in plasma and instantaneous charging process were assumed during simulations. Experimental measurements were carried out using Langmuir probe. Simulations and probe measurements were carried out before and after input of dust particles into plasma. Under the conditions studied both methods showed a decrease by a factor of 5 in electron density caused by input of dust nanoparticles. [ABSTRACT FROM AUTHOR]

Energy absorption of electromagnetic (EM) waves in collisional dusty plasmas is attracting much attention from researchers due to its applications in many fields, such as plasma antennas, blackout research during reentry, plasma stealth technology, and the design of microwave transmission in plasmas. In this paper, the propagation characteristics, in particular, the energy absorption effects of EM waves in partially ionized unmagnetized collisional dusty plasmas, are investigated. The results show that the effective energy absorption of EM waves is mainly due to the interaction between electrons and waves, and the plasmas with proper collisional frequencies can be used as a broadband frequency EM wave absorption medium with moderate absorption efficiency. Quantitative analyses of the characteristics of the EM waves that propagate in the collisional dusty plasmas are also included in this study. [ABSTRACT FROM AUTHOR]

Linear and nonlinear properties of obliquely propagating waves are studied in a degenerate dense cold magnetoplasma, comprising of Thomas–Fermi distributed electrons and ions as well as non-degenerate negatively charged dust particulates. By using the plane wave approximation, a linear dispersion relation for the dust-cyclotron (DC) and dust-acoustic (DA) waves is derived and analyzed numerically. For fully nonlinear waves, a Sagdeev pseudopotential theory is employed to derive an energy-balance equation and the soliton existence domain depending upon the dust concentration $(h)$ , obliqueness $(L_{z})$ , and Mach number $(M)$. Numerical analysis reveals that the parameter $h$ enhances the domain for allowed Mach numbers, i.e., $M_{1} < M < M_{2}$ and therefore favoring the solitary excitations, where $M_{1}$ and $M_{2}$ are the lower and upper Mach numbers, respectively. In addition, the dust concentration significantly reduces the amplitude and the profile sharpness of the solitary pulses. Similarly, variations in the obliqueness parameter and the Mach numbers modify the wave characteristics. This paper is important for understanding the nonlinear properties of electrostatic excitations in degenerate dusty magnetoplasma, relevant to white dwarfs (WDs), namely $GD56,\,\,GD29-38,\,\,GD362$ , and $WD2115-560$ , being termed as the DUSTY DAZ WDs. [ABSTRACT FROM AUTHOR]

In this paper, we present the results of experimental investigation of the properties of dusty plasma formed in a pulsed plasma accelerator (IPU-30) through the interaction of pulsed plasma beams with a carbon-based target. In the experiments, the interaction of beams of the pulsed plasma with the surface of the carbon plates affords instantaneous heating of the target substrate and subsequent ejection of dust particles from the surface of the plates into the plasma bulk. These dust particles are dragged by the plasma beam creating a moving plasma-dust cloud. A high-speed camera (Phantom VEO710S) is used to obtain the velocity of the dust particles in a beam of the pulsed plasma. Ejection of dust particles is investigated at two different values of the discharge voltage (7 and 12 kV). [ABSTRACT FROM AUTHOR]

Over the past 25 years, the dust acoustic wave has been a subject of intense study and the impact that thermal effects have on the dispersion relation has been a subject of investigation. Recently, a theory of dust correlations and the effect that these correlations have on the propagation of compressional modes has been developed that incorporates the effects of the confinement of the dust cloud in a finite volume within the larger plasma volume. This paper applies this model to a systemic study of the dispersion relation over a wide range of experimental conditions in a radio frequency (RF) discharge plasma. It is found the dust thermal pressure is larger than the dust electrostatic pressure and that both pressures are the square of the dust charge calculated using the orbit-motion-limited (OML) theory. It is also observed that the dust temperature and thermal pressure decreases with increasing neutral gas pressure. [ABSTRACT FROM AUTHOR]

Modeling the dynamics of charged dust particles, confined in a glass box placed on the lower electrode of a Gaseous Electronics Conference cell, requires that the interactions between the charged dust, plasma, and boundaries need to be accounted for in a self-consistent manner. The charged lower electrode affects the plasma conditions throughout the glass box, altering the electron and ion densities and temperatures within the plasma sheath. These plasma characteristics determine the charge collected on the walls of the surrounding glass box, the electric potential within the glass box, the dust charge, and ultimately the dynamics of the dust. This paper describes the steps taken to build a simple model of the relationship between the plasma conditions and the potential within the box as well as the expected dust charge near the center of the box. The calculated potential and dust charge are used to construct acceleration maps for the dust, which are compared to experimentally measured acceleration of the dust within the box. [ABSTRACT FROM AUTHOR]

In complex plasma, asymmetric ion flow toward the sheath gives rise to a well-known attractive oscillatory wake potential. In this paper, an investigation of effect of ion flow-induced wake potential on thermal conductivity and shear viscosity in strongly coupled complex plasmas has been reported for the first time. Green–Kubo formalism along with Langevin dynamics simulation has been used to estimate the thermal conductivity and the shear viscosity of strongly coupled dust fluid in the presence of external magnetic field and attractive wake potential superimposed with repulsive Debye–Hückel potential for a wide range of the Coulomb coupling parameter ($\Gamma $), the screening parameter ($\kappa $), the neutral pressure ($n_{\mathrm{ n}}$), and the magnetic field $B$. [ABSTRACT FROM AUTHOR]

This paper presents an analysis of the application of the time-resolved Hilbert transform to simulated measurements of the wave structure in the dust acoustic wave. It is shown that the observation of structures in the dominant frequency modes that have been made in experimental measurements of the driven dust acoustic wave is due to the nonlinearity in the wave mode and that the time-resolved Hilbert transform can be used to measure the nonlinearity in the driven wave mode. This was tested on experimental data and excellent agreement was observed. [ABSTRACT FROM PUBLISHER]

In this paper, the influence of the additional impact of electrostatic field on dusty and buffer plasma parameters is investigated. It is shown that the addition of a light gas to heavy one and the additional impact of a constant field on the radio frequency discharge lead to changes in the spatial characteristics of the buffer plasma and the location of the plasma-dust structure in the interelectrode space. [ABSTRACT FROM PUBLISHER]

Intermediate-luminosity red transients (ILRTs) are a class of observed transient posited to arise from the production of an electron-capture supernova from a super-asymptotic giant branch star within a dusty cocoon. In this paper, we present a systematic analysis of narrow Na  i D absorption as a means of probing the circumstellar environment of these events. We find a wide diversity of evolution in ILRTs in terms of line strength, time-scale, and shape. We present a simple toy model designed to predict this evolution as arising from ejecta from a central supernova passing through a circumstellar environment wherein Na  ii is recombining to Na  i over time. We find that while our toy model can qualitatively explain the evolution of a number of ILRTs, the majority of our sample undergoes evolution more complex than predicted. The success of using the Na  i D doublet as a diagnostic tool for studying circumstellar material will rely on the availability of regular high-resolution spectral observations of multiple ILRTs, and more detailed spectral modelling will be required to produce models capable of explaining the diverse range of behaviours exhibited by ILRTs. In addition, the strength of the Na  i D absorption feature has been used as a means of estimating the extinction of sources, and we suggest that the variability visible in ILRTs would prevent such methods from being used for this class of transient, and any others showing evidence of variability. [ABSTRACT FROM AUTHOR]

Effects of nonuniform weakly ionized dusty plasma on the polarization properties of obliquely incident electromagnetic (EM) waves were theoretically investigated in this paper. The dielectric coefficient of magnetized dusty plasma is obtained based on the Bhatnagar–Gross–Krook collision model. Then, the effects of external magnetic field, dust radii, and density on the polarization mismatch loss of obliquely incident EM waves in the L-band were analyzed using the equivalent impedance method. Results indicate that the larger the external magnetic field, the greater the polarization mismatch loss. In addition, we also found that dusty particles alleviate the deterioration of the polarization state significantly; regulating and controlling dust radius and density can avoid polarization reversal and reduce the polarization mismatch loss. We further analyzed the variation of the polarization state under different reentry heights. Our analysis reveals interesting features concerning polarization properties of obliquely incident EM waves, which provide an important theoretical basis for information reception in the plasma sheath containing ablative particles. [ABSTRACT FROM AUTHOR]

Under investigation is the discrete modified Korteweg-de Vries (mKdV) equation, which is an integrable discretization of the continuous mKdV equation that can describe some physical phenomena such as dynamics of anharmonic lattices, solitary waves in dusty plasmas, and fluctuations in nonlinear optics. Through constructing the discrete generalized m , N − m -fold Darboux transformation for this discrete system, the various discrete soliton solutions such as the usual soliton, rational soliton, and their mixed soliton solutions are derived. The elastic interaction phenomena and physical characteristics are discussed and illustrated graphically. The limit states of diverse soliton solutions are analyzed via the asymptotic analysis technique. Numerical simulations are used to display the dynamical behaviors of some soliton solutions. The results given in this paper might be helpful for better understanding the physical phenomena in plasma and nonlinear optics. [ABSTRACT FROM AUTHOR]

Present paper studies the contribution of both the quantum effect and the dust size distribution effect on the shock wave characters. It is concluded that the quantum effect of dust particles is negligible, while the quantum effects of both electrons and ions on the shock wave of a quantum dusty plasma cannot be neglected in certain cases. It is found that the speed and the amplitude of the shock wave, considering the dust size distribution, are larger than that of the quantum dusty plasma with the average dust size of a monosized dust plasma. Furthermore, the speed and the amplitude of the shock wave increase, while the width of the shock wave decreases as the ratios of the maximum dust size to the minimum one increases. The quantum effects may affect both the amplitude and width of the shock wave, while it has no effect on the shock wave speed. The width of the shock wave increases, while its amplitude decreases as H e and H i increase. [ABSTRACT FROM AUTHOR]

In this paper, the propagation properties of a terahertz (THz) wave in a collisional and inhomogeneous dusty plasma with a ceramic substrate and oblique angle of incidence are studied using the scattering matrix method. The influence of the various corresponding parameters, such as the frequency of the THz wave, angle of incidence, electron density, radius and density of the dust particles, and the collision frequency, on the absorbance and transmittance is calculated. The results of the simulation indicate that an increase in the wave frequency increases the transmittance and decreases the absorbance. Moreover, the absorbance of a THz wave in a dusty plasma with a ceramic substrate increases with an increase in the incident angle, maximum electron density, coefficient of steepness, density and radius of the dust particles, and collision frequency. These results provide an important theoretical basis for the problem of communication blackout between ground and spacecraft. [ABSTRACT FROM AUTHOR]

This paper studies the (3 + 1) extended Zakharov–Kuznetsov (EZK) dynamical equation that is utilized to describe nonlinear three-dimensional dust-ion-acoustic solitary waves in a magnetized two-ion-temperature dusty plasma. The bifurcation theory for planar dynamical systems is applied to the EZK equation. For a given restriction on the parameters, some new traveling wave solutions are characterized in terms of Jacobi-elliptic functions. These solutions are clarified in a graphical way. Physically, these wave solutions represent the related electric potential. Based on Maxwell equations, we calculate the corresponding electric magnetic fields, and we clarify them graphically. [ABSTRACT FROM AUTHOR]

In this paper, characteristics of small amplitude nonlinear dust acoustic wave have been investigated in a unmagnetized, collisionless, Lorentzian dusty plasma where electrons and ions are inertialess and modeled by generalized Lorentzian Kappa distribution. Dust grains are inertial and equilibrium dust charge is negative. Both adiabatic and nonadiabatic fluctuation of charges on dust grains have been taken under consideration. For adiabatic dust charge variation reductive perturbation analysis gives rise to a KdV equation that governs the nonlinear propagation of dust acoustic waves having soliton solutions. For nonadiabatic dust charge variation nonlinear propagation of dust acoustic wave obeys KdV-Burger equation and gives rise to dust acoustic shock waves. Numerical estimation for adiabatic grain charge variation shows the existence of rarefied soliton whose amplitude and width varies with grain charges. Amplitude and width of the soliton have been plotted for different electron Kappa indices keeping ion velocity distribution Maxwellian. For non adiabatic dust charge variation, ratio of the coefficients of Burger term and dispersion term have been plotted against charge fluctuation for different kappa indices. All these results approach to the results of Maxwellian plasma if both electron and ion kappa tends to infinity. [ABSTRACT FROM AUTHOR]

This paper discusses the design of the new Magnetized Dusty Plasma eXperiment (MDPX) device that is currently under construction at Auburn University. This device, which is envisioned to be operated as a multiuser facility, has incorporated many of the features of current dusty plasma experiments that make use of strong magnetic fields while adding new features—such as an extended plasma volume, programmable linear magnetic field gradients, and variable magnetic field geometries—that will greatly extend the operating space of the new device. This paper discusses the physics criteria used to define the operating parameters of the MDPX device and presents a discussion of the initial configuration of the experiment. [ABSTRACT FROM PUBLISHER]

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A new technique for investigating dust charging in the PMSE (polar mesospheric summer echoes) source region is proposed and discussed in this paper. The first high‐frequency (HF) modulation of the PMSE with varying pump power was employed during a recent experimental campaign at EISCAT (European Incoherent Scatter Scientific Association). Two experiment setups including HF pump power stepping as well as quasi‐continuous power sweeping were used. The experiment was designed based on a computational model capable of simulation of PMSE evolution during HF pump modulation in order to develop a new approach for studying the dust charging process in the PMSE source region. The charge state of dust particles along with background dusty plasma parameters is estimated using the experimental and computational results. A detailed future experimental design based on background dusty‐plasma parameters is proposed. Key Points: First radio modulation of PMSE source region with varying HF pump power is presentedDirect observation of dust charging in the mesosphere through controlled Te/Ti is observedPower stepping and continuous power sweeping can be used for charge state validation and saturated charge state determination, respectively [ABSTRACT FROM AUTHOR]

In this paper, the effect of charge gradient in a one-dimensional dusty plasma crystal is considered to investigate shock structure. Under the continuum limit, the nonlinear Korteweg–de Vries (KdV)–Burgers equation with a charge gradient effect is derived using the reductive perturbation method. Then, the shock solution based on the KdV–Burgers equation is obtained. The influence of the parameter ε, which measures the effect of charge gradient on the dynamic of the shock wave, is discussed in detail. It is found that the shock amplitude and strength increase with the increase in the parameter ε. Furthermore, it is also found that charge gradient effect makes oscillatory shock more easily converted to monotonic shock. [ABSTRACT FROM AUTHOR]

The quantum hydrodynamic model is considered to investigate the Jeans instability of three species ultracold inhomogeneous dusty plasma. The formulation of this paper is based on the assumption that the electron and ion inertial force is negligible in comparison with the electron and ion pressure and force associated with the electron and ion correlations at the quantum scale. The gravitational force acting on the negatively charged dust grains is considered in the presence of both the electrostatic and polarization forces taking into account the quantum diffraction and statistical contributions of dust particles. The modified dispersion relation is derived and analyzed to obtain the instability criterion by including the dust polarization force and the quantum corrections. Numerical results are presented to show the effect of these modifications on the growth rate of Jeans instability. The present investigation is relevant to the collapse of ultracold astrophysical objects like the inner core of white dwarf and neutron star. [ABSTRACT FROM PUBLISHER]

We made use of a combination of three models that describe plasma equilibrium, cluster kinetics, and aerosol dynamics in order to investigate solid carbonaceous dust formation in a dc gas discharge where the carbon source is provided by a graphite cathode sputtering. This enabled us to determine the time evolution of some of the particle characteristics, e.g., total density, mean diameter, and average charge, as a function of the sputtering yield. We showed that for a few minutes of discharge duration, the particle density reaches 10^7 – 10^8 cm ^-3 , the particle mean diameter is approximately 40 nm and the particle size distributions are bimodal for all the investigated conditions. We also showed that the variation of the sputtering yield affects in a quite unexpected way the interplay between the phenomena involved in the aerosol dynamics. Basically, larger sputtering yields result in larger density and coagulation rate on one hand, and in a limited nucleation and surface sticking kinetics on the other hand. [ABSTRACT FROM PUBLISHER]

In this paper, the effect of the magnetic field on dust dynamic and lifetime in the edge fusion plasma has been studied. A computational model of tungsten dust evolution formed on the surface of the reactor wall was constructed on the basis of particle-in-cell and Monte Carlo methods. The time dependence of the characteristic parameters (charge, temperature and radius, and heat fluxes) of the dust particle was determined. On the basis of these calculations, estimates of the tungsten dust lifetime in the edge fusion plasma were made. It was found that the magnetic field can have a significant effect on charging processes and lifetime of dust particles in the edge fusion plasma. The obtained results show that the larger the dust particle size, the stronger the magnetic field affects its charge, which leads to the suppression of the heat flux of plasma particles on the dust surface and an increase in its lifetime. Also, the magnetic field increases the charging time of small dust particles due to the limitation of the trajectory along the magnetic field lines. [ABSTRACT FROM AUTHOR]

Incandescent dust particles are observed to the naked eye in pure acetylene plasmas excited at electron cyclotron resonance (ECR). Their transport in a plane parallel to the magnets is studied using fast imaging combined with a tracking algorithm. The dynamics of dust particles exhibit specific trends depending on the direction considered within the magnetic field ($\vec {B}$), the position in the plasma reactor, and the time after plasma ignition. This transport is discussed considering the electric and the ion drag forces. Although the transport of dust particles is governed by the space-charge electric field in the direction parallel to $\vec {B}$ , it involves cross-field mechanisms in the direction perpendicular to $\vec {B}$ related, specifically, to the ambipolar $\boldsymbol { }\vec {E}\boldsymbol {\times }\vec {B}$ drift as supported by a simple model. However, to fully describe these transport phenomena, one would also consider spatial and time-evolutions of plasma parameters in the dusty plasma. [ABSTRACT FROM AUTHOR]

Dust kinetic temperature is a measure of the energy of the stochastic motion of a dust particle and is a result of the combination of the Brownian motion and the fluctuations in the dust charge and confining electric field. A method using the equilibrium value of the mean square displacement was recently introduced to obtain the dust kinetic temperature experimentally. As a follow up, this paper investigates the relationship between the dust kinetic energy derived from the mean square displacement technique and a technique using the probability distribution of the displacements obtained from random fluctuations of the dust particle. The experimental results indicate that the harmonic confinement potential acting on the dust particle can be obtained by combining the two methods, allowing the nonlinear effect of the confining force to be investigated. The thermal expansion in a 1-D vertical chain is discussed as a representative application as it is related to the nonlinear confinement force, or the asymmetric confinement potential. [ABSTRACT FROM AUTHOR]

The effect of an external magnetic field on the dust particle charging in gas discharge plasmas has been studied using the particle-in-cell and Monte Carlo methods at 1, 2, and 4 T. This paper presents the results for the dust particle charge and the characteristic dust particle charging time for different values of the magnetic field induction. Our simulations have shown that the external magnetic field reduces the absolute value of the dust particle charge and extends the characteristic charging time. In addition, the number density of electrons and ions decreases in the vicinity of the dust particle due to the magnetic force, which we interpret as the action of the external magnetic field hampering plasma flow to the surface of the charged dust particle. To visualize this effect, we show the trajectories of the electrons and ions around the dust particle at different values of the magnetic field induction. [ABSTRACT FROM AUTHOR]

An experimental method of producing dusty plasma with high dusty particle density is proposed and implemented. Microdusty particles are immersed into an ac glow discharge plasma with large scale by applying electronically controlled vibratory screen mesh and continuous equidistributional dusty environment is formed. The impact of dusty particles on microwave propagation in a laboratory plasma device can be observed. The gigahertz microwave transmittance through the dusty plasma region is measured with vector network analyzer and horn antenna placed in the sides of plasma region. The results show that the dusty particles can synergize the influence on propagation of microwave in plasma. [ABSTRACT FROM AUTHOR]

Motivated by observations of localized electrostatic wavepackets by the Voyager 1 and 2 and Cassini missions in Saturn's magnetosphere, we have investigated the evolution of modulated electrostatic wavepackets in a dusty plasma environment. The well-known dust-ion acoustic (DIA) mode was selected to explore the dynamics of multidimensional structures, by means of a Davey–Stewartson (DS) model, by taking into account the presence of a highly energetic (suprathermal, kappa-distributed) electron population in combination with heavy (immobile) dust in the background. The modulational (in)stability profile of DIA wavepackets for both negative as well as positive dust charge is investigated. A set of explicit criteria for modulational instability (MI) to occur is obtained. Wavepacket modulation properties in 3D dusty plasmas are shown to differ from e.g. Maxwellian plasmas in 1D. Stronger negative dust concentration results in a narrower instability window in the K (perturbation wavenumber) domain and to a suppressed growth rate. In the opposite manner, the instability growth rate increases for higher positive dust concentration and the instability window gets larger. In a nutshell, negative dust seems to suppress instability while positive dust appears to favour the amplitude modulation instability mechanism. Finally, stronger deviation from the Maxwell–Boltzmann equilibrium, i.e. smaller κ e values, lead(s) to stronger instability growth in a wider wavenumber window – hence suprathermal electrons favour MI regardless of the dust charge sign (i.e. for either positive or negative dust). The wavepacket modulation properties in 2D dusty plasmas thus differ from e.g. Maxwellian plasmas in 1D, both quantitatively and qualitatively, as indicated by a generalized dispersion relation explicitly derived in this paper (for the amplitude perturbation). Our results can be compared against existing experimental data in space, especially in Saturn's magnetosphere. [ABSTRACT FROM AUTHOR]

Editorial. Introduces the articles featured in the April 2001 issue of the `IEEE Transactions on Plasma Science,' which deal with dusty plasmas. Background on dusty plasmas; Categories of the papers dealing with dusty plasmas; Dedication of the issue to physicist D. Asoka Mendis.

Investigation of linear dust-acoustic (DA) waves was analyzed in a system of collisionless, dissipative, and unmagnetized four-component dusty plasma consisting of cold positively and negatively charged particles of dust, with ions and electrons are of the Boltzmann distribution. The compatibility condition is obtained by using the normal mode analysis. The Korteweg de Vries–Burgers (KdV–Burgers) equation is obtained when the plasma system is nonlinearly analyzed by the reductive perturbation method. To study the nonlinear waves, we obtain some interesting physical solutions. These solutions are in the form of soliton, a combination between a shock and a soliton, and finally monotonic and oscillatory shock waves. Graphical illustration for these solutions was presented. The characteristics of the DA solitary and shock waves are significantly modified by the presence of positive and negative dust ions, the ratio of the ion to electron temperatures, and it is also found that the basic features are affected by the dust kinematic viscosity. The planar dynamical systems bifurcation theory, which was used to establish the existence of solitary wave solutions and periodic traveling wave solutions, has been established. Accordingly, the phase portrait topology and the potential diagram are illustrated for the KdV–Burgers equation. As a result of different phase orbits, there is an advantage to predict different classes of traveling wave solutions. The electric field is determined. Generalization of the obtained results in this paper can be used to investigate the nature of plasma waves in both laboratory and space. [ABSTRACT FROM AUTHOR]

The Einstein frequency $\Omega _{E}$ was experimentally determined for a 2-D dusty plasma. We found $\Omega _{E}= 49.4 ~\text{s}^{-1}$ and 50.2 s−1 for the collection of microspheres in a crystalline and liquid-like state, respectively. Comparing to the nominal 2-D dust plasma frequency $\omega _{\mathrm {pd}}$ , we found the ratio $\Omega _{ E}$ / $\omega _{\mathrm {pd}}\approx 1$ / $\surd 3$. This experimental ratio is consistent with previous predictions of Yukawa simulations. Our results were obtained by analyzing images of the microspheres to obtain their positions, charge, and the screening length; we used these measurements to calculate resonant frequencies of test particles. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

A theoretical investigation of the phase-mixing phenomenon of Langmuir oscillations (LOs) in a multi-component dusty plasma is presented. The plasma under study is a four-component plasma consisting of electrons, positrons, singly ionised positive ions and positive (or negative) polarity dust grains. The massive dust grains are assumed to form a fixed charge neutralising background, while the electrons, positrons and ions are considered to take part in the wave dynamics. A simple perturbative analysis of the governing fluid-Maxwell's equations leads us to an approximate relation for phase-mixing time of LOs, improving some earlier existing results. It is revealed that even though the dust grains remain motionless in the background, they still have significant impact on the phase-mixing process of LOs in such plasmas. It is found that the nature of the charge on the dust grains and the equilibrium dust density profoundly affect the phase-mixing time. The results of this investigation is expected to have relevance in space-plasma environments. [ABSTRACT FROM AUTHOR]

Arcs between carbon electrodes present some specific differences compared with metallic arcs. The arc voltage is higher, but does not attain a stable value displaying large fluctuations. Indeed, the arcs are produced by the direct sublimation of the electrodes, without passing through a molten phase. The arc production is also facilitated by both circuit breaking and electric field breakdown. In this paper, arcing has been examined under various conditions (voltage, current, and opening or fixed interelectrode gap) and particular attention has been given to the ability of the system to sustain the arc due to reignition. Small-angle X-ray scattering has been used to examine the formation of particles within carbon arcs and again the results are different from what is found with metallic electrodes, the particles being larger with rougher surfaces. The ultimate aim of this paper was to gain new knowledge concerning these arcs and their consequences for electrical safety (arc faults in wires). [ABSTRACT FROM PUBLISHER]

In this paper, a reductive perturbation theory is used to derive a Korteweg–de Vries equation for a magnetized dusty plasma consisting of cold dust grains, Boltzmann distributed electrons, and Boltzmann distributed ions at two different temperatures. The renormalization method is used to obtain stationary solutions of these coupled equations. The effects of two-temperature ions and external magnetic field on the properties of solitary waves are studied. Such a study showed that the presence of the hot and cold ions modifies the nature of dust-acoustic solitary structures and admits mainly solitary waves with negative potential. However, for a small amount of electron density, the plasma may allow rarefactive dust-acoustic solitary waves to exist in such a dusty plasma system. [ABSTRACT FROM PUBLISHER]

Over the past twenty years, the dust-acoustic wave (DAW) has been a subject of intense study. In this paper, high-speed video imaging is employed to measure the evolution of wavefronts of a propagating DAW as it propagates through a weakly coupled dusty plasma system in an argon dc glow discharge plasma. In particular, measurements of the growth, saturation, and, then, damping of the wave mode as the wave propagates through the cloud are reported. It is observed that the wave amplitude initially exhibits rapid growth while the wavefront compresses. After this initial growth, the width of the wavefront remains relatively constant, while the amplitude of the wavefront evolves like the background dust medium. In some cases, it is also observed that the wave amplitude can decay more quickly than the background dust medium. [ABSTRACT FROM PUBLISHER]