Effective Temperature of 2D Dusty Plasma Liquids at the Discrete Level
Io, C.-W.; Chan, C.-L.; I Lin
2007-07-13
Fluctuation-dissipation theory has been used to measure the effective temperature of non-equilibrium system. In this work, using a 2D dusty plasma liquid formed by the negatively charged fine particles suspending in weakly ionized discharges and sheared by two CW counter parallel laser beams, we measure the micro-transport at the kinetic level. The effective temperatures Teff at different time scales are obtained through the Stokes-Einstein relation which relates the diffusion coefficient (D) and the viscosity ({eta}). The external energy is cascaded from the slow hopping modes to the fast caging modes through mutual coupling, which leads to the higher effective temperature of the slow hopping modes.
Jones, M.E.; Winske, D.; Keinigs, R.; Lemons, D.
1996-05-01
This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The objective of this project has been to develop a fundamental understanding of dusty plasmas at the Laboratory. While dusty plasmas are found in space in galactic clouds, planetary rings, and cometary tails, and as contaminants in plasma enhanced fabrication of microelectronics, many of their properties are only partially understood. Our work has involved both theoretical analysis and self-consistent plasma simulations to understand basic properties of dusty plasmas related to equilibrium, stability, and transport. Such an understanding can improve the control and elimination of plasma dust in industrial applications and may be important in the study of planetary rings and comet dust tails. We have applied our techniques to the study of charging, dynamics, and coagulation of contaminants in plasma processing reactors for industrial etching and deposition processes and to instabilities in planetary rings and other space plasma environments. The work performed in this project has application to plasma kinetics, transport, and other classical elementary processes in plasmas as well as to plasma waves, oscillations, and instabilities.
Advances in Dusty Plasmas 5.Strongly Coupled Dusty Plasmas
NASA Astrophysics Data System (ADS)
Hamaguchi, Satoshi
We review thermodynamical and dynamical properties of strongly coupled dusty plasmas, focusing on the recent development of molecular dynamics (MD) simulations. In the present paper, dusty plasmas are modeled by the Yukawa system, which is a collection of particles interacting through Yukawa (i.e., screened Coulomb) potentials. The phase diagram, wave dispersion relations and some transport coefficients of Yukawa systems are discussed.
Numerical simulation of dusty plasmas
Winske, D.
1995-09-01
The numerical simulation of physical processes in dusty plasmas is reviewed, with emphasis on recent results and unresolved issues. Three areas of research are discussed: grain charging, weak dust-plasma interactions, and strong dust-plasma interactions. For each area, we review the basic concepts that are tested by simulations, present some appropriate examples, and examine numerical issues associated with extending present work.
Analysis Of Phase Transitions In Quasi-Two-Dimensional Dusty Systems In RF-Discharge Plasma
Adamovich, X. G.; Vaulina, O. S.; Khrustalev, Yu. V.; Nekhaevsky, Yu. Yu.; Petrov, O. F.; Fortov, V. E.
2008-09-07
In this work, we investigate the phase transitions in quasi-two-dimensional systems of dusty plasma in RF discharge. The quasi-2D systems are considered, where the areas with different phase states (dusty liquid and dusty crystal) coexist. The parameters of these areas of dusty subsystem are estimated, the obtained results are analysed and compared with theoretical predictions.
Interparticle Attraction in 2D Complex Plasmas
NASA Astrophysics Data System (ADS)
Kompaneets, Roman; Morfill, Gregor E.; Ivlev, Alexei V.
2016-03-01
Complex (dusty) plasmas allow experimental studies of various physical processes occurring in classical liquids and solids by directly observing individual microparticles. A major problem is that the interaction between microparticles is generally not molecularlike. In this Letter, we propose how to achieve a molecularlike interaction potential in laboratory 2D complex plasmas. We argue that this principal aim can be achieved by using relatively small microparticles and properly adjusting discharge parameters. If experimentally confirmed, this will make it possible to employ complex plasmas as a model system with an interaction potential resembling that of conventional liquids.
Shock wave in a two-dimensional dusty plasma crystal
Ghosh, Samiran
2009-10-15
Two-dimensional (2D) shock structures of longitudinal dust lattice wave (LDLW) in a hexagonal Yukawa crystal are studied. The nonlinear evolution equation derived for dusty plasma crystal is found to be a 2D Burgers' equation, where the Burgers' term, i.e., the dissipation is provided by ''hydrodynamic damping'' due to irreversible processes that take place within the system. Analytical and numerical solutions of this equation on the basis of crystal experimental parameters show the development of compressional shock structures of LDLW in 2D dusty plasma crystal. The shock strength decreases (increases) with the increase in lattice parameter {kappa} (angle of propagation of the nonlinear wave). The results are discussed in the context of 2D monolayer hexagonal dusty plasma crystal experiments.
Dusty-Plasma Particle Accelerator
NASA Technical Reports Server (NTRS)
Foster, John E.
2005-01-01
A dusty-plasma apparatus is being investigated as means of accelerating nanometer- and micrometer-sized particles. Applications for the dusty-plasma particle accelerators fall into two classes: Simulation of a variety of rapidly moving dust particles and micrometeoroids in outer-space environments that include micrometeoroid streams, comet tails, planetary rings, and nebulae and Deposition or implantation of nanoparticles on substrates for diverse industrial purposes that could include hardening, increasing thermal insulation, altering optical properties, and/or increasing permittivities of substrate materials. Relative to prior apparatuses used for similar applications, dusty-plasma particle accelerators offer such potential advantages as smaller size, lower cost, less complexity, and increased particle flux densities. A dusty-plasma particle accelerator exploits the fact that an isolated particle immersed in plasma acquires a net electric charge that depends on the relative mobilities of electrons and ions. Typically, a particle that is immersed in a low-temperature, partially ionized gas, wherein the average kinetic energy of electrons exceeds that of ions, causes the particle to become negatively charged. The particle can then be accelerated by applying an appropriate electric field. A dusty-plasma particle accelerator (see figure) includes a plasma source such as a radio-frequency induction discharge apparatus containing (1) a shallow cup with a biasable electrode to hold the particles to be accelerated and (2) a holder for the substrate on which the particles are to impinge. Depending on the specific design, a pair of electrostatic-acceleration grids between the substrate and discharge plasma can be used to both collimate and further accelerate particles exiting the particle holder. Once exposed to the discharge plasma, the particles in the cup quickly acquire a negative charge. Application of a negative voltage pulse to the biasable electrode results in the
Zakharov equations in quantum dusty plasmas
Sayed, F.; Vladimirov, S. V.; Ishihara, O.
2015-08-15
By generalizing the formalism of modulational interactions in quantum dusty plasmas, we derive the kinetic quantum Zakharov equations in dusty plasmas that describe nonlinear coupling of high frequency Langmuir waves to low frequency plasma density variations, for cases of non-degenerate and degenerate plasma electrons.
Optical diagnostics of dusty plasmas
NASA Astrophysics Data System (ADS)
Remy, Jerome Alphonse Robert
The central topic of this thesis is dusty plasmas, in which particles are generated or injected. Such plasmas, when ignited in silane-based gas mixtures, are widely used in the semiconductor industry for depositing silicon layers (amorphous, micro-crystalline or polymorphous). These layers have applications in flat panel displays, sensors, and solar cells for instance. The inclusion of nano-crystallites in the amorphous silicon layer produces cells with enhanced properties but calls at the same time for a better comprehension and control of the particles' formation and growth. The role played by silicon-based radical species in these processes more particularly prompts detailed studies. Dusty plasmas are also a field of enduring interest to the astrophysics community. The interstellar medium can be simulated in a laboratory plasma to identify the carbon-based molecular complexes (Polycyclic Aromatic Hydrocarbons or PAHs) whose ions are thought to be responsible for unidentified emission and absorption bands seen in the spectra of starlight. This thesis covers some aspects of both industry-oriented and astrophysical dusty plasmas. The experimental study on silane-based plasmas includes optical measurements performed in emission, absorption, and by analyzing the light scattered by particles grown in-situ. The negative charge acquired by the particles while immersed in the plasma disturbs their dynamics but also the electrical properties of the discharge. Based on the monitoring of the plasma impedance, it is shown that the plasma is affected by the particles' presence, independently from the nature of the silane carrier gas. Optical emission spectroscopy performed on SiH, H a and H 2 excited states indicates that the silane dissociation occurs in the vicinity of the RF-powered electrode. A Fourier Transform Infrared (FTIR) time-dependent analysis of the silane consumption after plasma ignition demonstrates that the silane dissociation is actually a slow but
Brodin, G.; Marklund, M.; Zamanian, J.
2008-09-07
A fluid model is derived, taking into account the effect of spin magnetization of electrons as well as of magnetized dust grains. The model is analyzed, and it is found that both the acoustic velocity and the Alfven velocity is decreased due to the magnetization effects. Furthermore, for low-temperature high density plasmas, it is found that the linear wave modes can be unstable, due to the magnetic attraction of individual fluid elements. The significance of our results are discussed.
NASA Astrophysics Data System (ADS)
Mendis, A.
2012-12-01
Ionized gases, contaminated with fine (nanometer to micrometer-sized) charged dust, loosely referred to a dusty plasmas, occur in a wide variety of cosmic and laboratory environments. In this topical review I will discuss the underlying theory of such plasmas, with emphasis on the space environment. Central to the discussion is the electrostatic charging of the dust grains by the various currents that they experience in the plasma and radiative environment in which they are immersed. This charging could lead to both physical and dynamical consequences for the dust as well as for the plasma. Among the physical effects for the dust are electrostatic disruption and electrostatic levitation from charged surfaces. The dynamics of the charged dust is affected by the Lorentz force they experience, since space plasmas are generally magnetized. The physical effects for plasma result from the fact that the dust can act both as a sink and as a source of electrons in different space environments. The dynamical effects on the plasma arise from the fact that the charged dust can alter the phase velocity of normal wave modes (e.g., the Ion acoustic mode) by changing the charge equilibrium in the plasma. Additionally the charged dust can also participate in the wave dynamics, leading, for example, to the very low frequency, novel, "dust-acoustic" wave that has been observed in the laboratory. Finally the possibility that charged dust in a space plasma, may indirectly influence the propagation of electromagnetic radiation through it, will also be, briefly, discussed.
Study of Photoemissive Dusty Plasma
Gavrikov, A. V.; Fortov, V. E.; Petrov, O. F.; Babichev, V. N.; Filippov, A. V.; Pal', A. F.; Starostin, A. N.
2008-09-07
The present work deals with the experimental and theoretical investigation of photoemissive charging of polydisperse dust particles. The characteristic size of dust particles under consideration was 0.1-25 mkm. The experimental part of this work was devoted to the study of positive charging of macroparticles under UV-radiation that acted on dusty formations. Investigations were carried out in argon at normal pressure with particles of different materials. Dust structure was subjected to radiation. The power and frequency spectrum of this radiation was close to corresponding parameters of sun radiation near the top layers of Earth atmosphere. Owing to electron photoemission the macroparticles became positively charged. On the basis of experimental data the estimation of this charge was performed. It was about 500 elementary charges for micron particles. The theoretical part of present work included the numerical simulation of photoemissive dusty plasma decay in a drift-diffusion approximation. The model included equilibrium equation for positively charged macroparticles (in experiment, the percent of these particles was about 90), negatively charged dust particles (about 10%), positive ions (those were born by electron strike of buffered gas atoms) and electrons. Also the model included the Poisson equation for determination of potential distribution in the discharge region. The results of numerical calculations were in a satisfactory correspondence with experimental data both for time dependences of positively and negatively charged macroparticles concentrations and for their velocities.
Cooperative particle motion in complex (dusty) plasmas
NASA Astrophysics Data System (ADS)
Zhdanov, Sergey; Morfill, Gregor
2014-05-01
Strongly coupled complex (dusty) plasmas give us a unique opportunity to go beyond the limits of continuous media and study various generic processes occurring in liquids or solids at the kinetic level. A particularly interesting and challenging topic is to study dynamic cooperativity at local and intermediate scales. As an important element of self-organization, cooperative particle motion is present in many physical, astrophysical and biological systems. As a rule, cooperative dynamics, bringing to life 'abnormal' effects like enhanced diffusion, self-dragging, or self-propelling of particles, hold aspects of 'strange' kinetics. The synergy effects are also important. Such kind of cooperative behavior was evidenced for string-like formations of colloidal rods, dynamics of mono- and di-vacancies in 2d colloidal crystals. Externally manipulated 'dust molecules' and self-assembled strings in driven 3d particle clusters were other noticeable examples. There is a certain advantage to experiment with complex plasmas merely because these systems are easy to manipulate in a controllable way. We report on the first direct observation of microparticle cooperative movements occurring under natural conditions in a 2d complex plasma.
Collisional Effects in Complex (Dusty) Plasmas
Khrapak, S. A.
2008-09-07
This is a short overview of recent results demonstrating the importance of ion-neutral collisions for different processes naturally occurring in complex (dusty) plasmas. Most important developments are briefly discussed and relevant references are provided.
Experiments and Theory of Dusty Plasmas
Shukla, P. K.
2011-11-29
The purpose of this paper is to present the most important theoretical and experimental discoveries that have been made in the area of dusty plasma physics. We describe the physics and observations of the well celebrated dust acoustic wave (DAW) and the dust ion-acoustic wave (DIAW) in dusty plasmas with weakly coupled dust grains, as well as the dust Coulomb crystal and dust lattice oscillations (DLOs) in dusty plasmas with strongly coupled dust grains. In dusty plasmas, the dust charge fluctuation is a dynamical variable, which provides a novel collisionless damping of the DA and DIA waves. The latter and the DLOs are excited by external sources, which are here discussed. Besides the Debye-Hueckel short-range repulsive force between like charged dust grains, there are novel attractive forces (e.g. due to dipole-dipole dust particle interactions, overlapping Debye spheres, ion focusing and ion wakefields, dipole magnetic moments etc.), which provide unique possibilities for attracting charged dust particles of similar polarity. The dust particle attraction is responsible for the formation of dust Coulomb crystals in laboratory dusty plasmas, as well as for the formation of planets and large astrophysical bodies in the Milky Way galaxy and in interstellar media. Furthermore, the nonlinear DAW, DIAW, and DLOs also appear in the form of solitary and shock waves, the physics and observations of which are briefly discussed. Finally, we discuss possible applications of dust-in-plasmas and dusty plasmas in laboratory and space.
Dusty Plasmas in Planetary Magnetospheres Award
NASA Technical Reports Server (NTRS)
Horanyi, Mihaly
2005-01-01
This is my final report for the grant Dusty Plasmas in Planetary Magnetospheres. The funding from this grant supported our research on dusty plasmas to study: a) dust plasma interactions in general plasma environments, and b) dusty plasma processes in planetary magnetospheres (Earth, Jupiter and Saturn). We have developed a general purpose transport code in order to follow the spatial and temporal evolution of dust density distributions in magnetized plasma environments. The code allows the central body to be represented by a multipole expansion of its gravitational and magnetic fields. The density and the temperature of the possibly many-component plasma environment can be pre-defined as a function of coordinates and, if necessary, the time as well. The code simultaneously integrates the equations of motion with the equations describing the charging processes. The charging currents are dependent not only on the instantaneous plasma parameters but on the velocity, as well as on the previous charging history of the dust grains.
MHDust: A 3-fluid dusty plasma code
NASA Astrophysics Data System (ADS)
Lazerson, Samuel
MHDust is a next generation 3-fluid magnetized dusty plasma code, treating the inertial dynamics of both the dust and ion components. Coded in ANSI C, the numerical method employs Leap-Frog and Dufort-Frankel integration schemes. Features include: nonlinear collisional terms, quasi-neutrality or continuity based electron densities, and dynamical dust charge number. Tests of wave-mode propagation (Acoustic and Electromagnetic) allow a comparison to linear wave mode theory. Additional nonlinear phenomena are presented including magnetic reconnection and shear-flow instabilities. Relevant parameters for the space environment are considered, allowing a comparison to be made with previous dusty plasma codes (DENISIS). The utility of the code is expanded through the possibility of small dust mass. This allows MH- Dust to be used as a 2-ion plasma code. MHDust considerably expands the range of numerical investigations into nonlinear phenomena in the field of astrophysical dusty plasmas.
Nonplanar waves with electronegative dusty plasma
Zobaer, M. S.; Mukta, K. N.; Nahar, L.; Mamun, A. A.; Roy, N.
2013-04-15
A rigorous theoretical investigation has been made of basic characteristics of the nonplanar dust-ion-acoustic shock and solitary waves in electronegative dusty plasma containing Boltzmann electrons, Boltzmann negative ions, inertial positive ions, and charge fluctuating (negatively charged) stationary dust. The Burgers' and Korteweg-de Vries (K-dV) equations, which is derived by reductive perturbation technique, is numerically solved to examine the effects of nonplanar geometry on the basic features of the DIA shock and solitary waves formed in the electronegative dusty plasma. The implications of the results (obtained from this investigation) in space and laboratory experiments are briefly discussed.
Application of Dusty Plasmas for Space
NASA Astrophysics Data System (ADS)
Bhavasar, Hemang; Ahuja, Smariti
In space, dust particles alone are affected by gravity and radiation pressure when near stars and planets. When the dust particles are immersed in plasma, the dust is usually charged either by photo ionization, due to incident UV radiation, secondary electron emission, due to collisions with energetic ions and electrons, or absorption of charged particles, due to collisions with thermal ions and electrons. A 1 micron radius dust particle in a plasma with an electron temperature of a few eV, will have a charge corresponding to a few thousand electron volts, with a resulting charge to mass ratio, Q/m ¡1. They will also be affected by electric and magnetic fields. Since the electrons are magnetized in these regions, electron E B or diamagnetic cross-field drifts may drive instabilities. Dust grains (micron to sub-micron sized solid particles) in plasma and/or radiative environments can be electrically charged by processes such as plasma current collection or photoemission. The effect of charged dust on known electrojet instabil-ities and low frequency dust acoustic and dust drift instabilities. As the plasma affects the dust particles, the dust particles can affect the plasma environment. In Dust Plasma, Plasma is Combination of ions and electrons. Dusty plasmas (also known as complex plasmas) are ordinary plasmas with embedded solid particles consisting of electrons, ions, and neutrals. The particles can be made of either dielectric or conducting materials, and can have any shape. The typical size range is anywhere from 100 nm up to say 100 m. Most often, these small objects or dust particles are electrically charged. Dusty plasmas are ubiquitous in the universe as proto-planetary and solar nebulae, molecular clouds, supernova explosions, interplanetary medium, circumsolar rings, and steroids. Closer to earth, there are the noctilucent clouds, clouds of tiny (charged) ice particles that form in the summer polar mesosphere at an altitude of about 85 km. In processing
Lunar Dust and Dusty Plasma Physics
NASA Technical Reports Server (NTRS)
Wilson, Thomas L.
2009-01-01
In the plasma and radiation environment of space, small dust grains from the Moon s surface can become charged. This has the consequence that their motion is determined by electromagnetic as well as gravitational forces. The result is a plasma-like condition known as "dusty plasmas" with the consequence that lunar dust can migrate and be transported by magnetic, electric, and gravitational fields into places where heavier, neutral debris cannot. Dust on the Moon can exhibit unusual behavior, being accelerated into orbit by electrostatic surface potentials as blow-off dust, or being swept away by moving magnetic fields like the solar wind as pick-up dust. Hence, lunar dust must necessarily be treated as a dusty plasma subject to the physics of magnetohydrodynamics (MHD). A review of this subject has been given before [1], but a synopsis will be presented here to make it more readily available for lunar scientists.
Structural Analysis of Dusty Plasma Formations Based on Spatial Spectra
Khakhaev, A. D.; Luizova, L. A.; Piskunov, A. A.; Podryadchikov, S. F.; Soloviev, A. V.
2008-09-07
Some advantages of studying the structure of dusty plasma formations using spatial spectra are illustrated by simulated experiments and by processing actual images of dusty structures in dc glow discharge in inert and molecular gases.
Turbulence in strongly coupled dusty plasmas using generalized hydrodynamic description
Tiwari, Sanat Kumar; Dharodi, Vikram Singh; Das, Amita; Patel, Bhavesh G.; Kaw, Predhiman
2015-02-15
The properties of decaying turbulence have been studied with the help of a Generalized Hydrodynamic (GHD) fluid model in the context of strongly coupled dusty plasma medium in two dimensions. The GHD model treats the strongly coupled dusty plasma system as a visco-elastic medium. The incompressible limit of the GHD model is considered here. The studies carried out here are, however, applicable to a wider class of visco-elastic systems, and are not merely confined to the dusty plasma medium. Our simulations studies show that an initial spectrum that is confined in a limited domain of wave numbers becomes broad, even when the Reynold's number is much less than the critical value required for the onset of turbulence in Newtonian fluids. This is a signature of elastic turbulence, where Weissenberg's number also plays an important role on the onset of turbulence. This feature has been observed in several experiments. It is also shown that the existence of memory relaxation time parameter and the transverse shear wave inhibit the normal process (for 2-D systems) of inverse spectral cascade in this case. A detailed simulation study has been carried out for the understanding of this inhibition.
A Proposed Magnetized Dusty Plasma User Facility
NASA Astrophysics Data System (ADS)
Thomas, E.; Merlino, R. L.; Rosenberg, M.
2009-11-01
As the experimental study of dusty (complex) plasmas has advanced over the last two decades, a great deal of new insight has been gained on the complex interaction between the background plasma and charged microparticles. Even through the charged dust grains in a typical experiment can acquire several thousand elementary charges, the large mass of the grains ensures that the charge-to-mass ratio is quite low. As a result, it has been considered experimentally challenging to design an experiment that can achieve full magnetization of ions, electrons, and the charged dust grains. However, with continuing improvements in magnet design and sub-micron particle imaging technologies, it is now possible to contemplate the development of a Magnetized Dusty Plasma Facility. This presentation discusses the design, experimental parameters, and scientific motivation for a flexible, superconducting, 4 Tesla magnetic field user facility for the study of magnetized dusty plasmas. This work is supported by NSF grant number PHY-0936470 (AU), DOE Grant No. DE-FG01-04ER54795 (UI) and DOE Grant No. DE-FG02-04ER54804 (UCSD)
Discrete breathers in hexagonal dusty plasma lattices
Koukouloyannis, V.; Kourakis, I.
2009-08-15
The occurrence of single-site or multisite localized vibrational modes, also called discrete breathers, in two-dimensional hexagonal dusty plasma lattices is investigated. The system is described by a Klein-Gordon hexagonal lattice characterized by a negative coupling parameter epsilon in account of its inverse dispersive behavior. A theoretical analysis is performed in order to establish the possibility of existence of single as well as three-site discrete breathers in such systems. The study is complemented by a numerical investigation based on experimentally provided potential forms. This investigation shows that a dusty plasma lattice can support single-site discrete breathers, while three-site in phase breathers could exist if specific conditions, about the intergrain interaction strength, would hold. On the other hand, out of phase and vortex three-site breathers cannot be supported since they are highly unstable.
Waves in a 1D electrorheological dusty plasma lattice
NASA Astrophysics Data System (ADS)
Rosenberg, M.
2015-08-01
The behavior of waves in a one-dimensional (1D) dusty plasma lattice where the dust interacts via Yukawa and electric dipole interactions is discussed theoretically. This study is motivated by recent reports on electrorheological dusty plasmas (e.g. Ivlev et al. 2008 Phys. Rev. Lett. 100, 095003) where the dipole interaction arises due to an external uniaxial AC electric field that distorts the Debye sphere surrounding each grain. Application to possible dusty plasma experimental parameters is discussed.
Viscoplastic Deformation of Crystal-like Dusty Plasma Structures
Fortov, V. E.; Gavrikov, A. V.; Goranskaya, D. N.; Ivanov, A. S.; Petrov, O. F.; Timirkhanov, R. A.
2008-09-07
The experimental investigation of a dusty plasma liquid without shearing forces is presented. The boundary value of coupling parameter was determinated, at which clusters began to form. The possible explanation of non-Newtonian behavior of dusty plasma liquid was suggested. The second part of the present work is devoted to the experimental study of viscoplastic flow in the dusty plasma crystal. It was for the first time the viscoplastic flow of dusty plasma crystal was obtained. The threshold type of this viscoplastic flow was demonstrated.
Time of relaxation in dusty plasma model
NASA Astrophysics Data System (ADS)
Timofeev, A. V.
2015-11-01
Dust particles in plasma may have different values of average kinetic energy for vertical and horizontal motion. The partial equilibrium of the subsystems and the relaxation processes leading to this asymmetry are under consideration. A method for the relaxation time estimation in nonideal dusty plasma is suggested. The characteristic relaxation times of vertical and horizontal motion of dust particles in gas discharge are estimated by analytical approach and by analysis of simulation results. These relaxation times for vertical and horizontal subsystems appear to be different. A single hierarchy of relaxation times is proposed.
Mode-coupling instability of monolayer complex (dusty) plasmas
NASA Astrophysics Data System (ADS)
Zhdanov, Sergey; Ivlev, Alexei; Morfill, Gregor
2010-05-01
Strongly coupled complex (dusty) plasmas give us a unique opportunity to go beyond the limits of continuous media and study various generic processes occurring in liquids or solids, in regimes ranging from the onset of cooperative phenomena to large strongly coupled systems at the most detailed kinetic (atomistic) level. On the other hand, there is certain peculiarity of the interparticle interactions in complex plasmas. This can be easily understood if we divide the complete set of elementary charges in complex plasmas into two distinct categories - a subsystem of charges bound to the microparticles, and a subsystem of free plasma charges in the surrounding wakes. Plasma wakes play the role of a "third body" in the mutual particle-particle interaction and, hence, make the pair interaction nonreciprocal. We carried out rigorous theoretical investigation of the DL wave mode coupling occurring in 2D complex plasmas due to particle-wake interactions. The analysis of the mode coupling shows that if the strength of the vertical confinement is below a certain critical value, then resonance coupling between the longitudinal in-plane mode and out-of-plane mode sets in. This results in the emergence of a hybrid mode and drives the mode-coupling instability. The universal dependence of the critical confinement frequency on plasma parameters is calculated, which allows us to specify the conditions when stable 2D highly ordered complex plasma can be formed in experiments.
The Lunar Surface: A Dusty Plasma Laboratory
NASA Astrophysics Data System (ADS)
Horanyi, M.; Brain, D.; Kempf, S.; Munsat, T.; Robertson, S. H.; Sternovsky, Z.
2011-12-01
The lunar surface is an excellent laboratory to study dusty plasma processes that are relevant to all airless planetary objects. The solar wind and UV radiation lead to charging of exposed surfaces, and the formation of plasma sheaths above them. Near-surface intense electric fields are thought to be capable of mobilizing and transporting small charged dust particles. Remote sensing and in situ observations indicating dust transport on the Moon date back to the Apollo era and remain highly controversial. There are many unresolved issues about the physical processes that have to this point prevented the development of a coherent explanation for the existing observations. Dust transport on airless bodies can significantly alter our interpretation of spectral identification of asteroids, the small-scale surface features of Mercury, and the Martian moons Phobos and Deimos. Understanding the behavior of dust laden plasma sheaths is of interest in basic plasma and planetary sciences, and holds the key to efficient dust hazard mitigation for the long-term use of optical and mechanical equipment used for robotic and/or human exploration. NASA Lunar Science Institute's Colorado Center of Lunar Dust is focused on experimental and theoretical investigations of dusty plasmas, and the effects of hypervelocity dust impacts on surfaces. This presentation will describe a series of small-scale laboratory experiments investigating the properties of photoelectron sheaths, and the emergence of intense electric fields near boundaries of lit and dark surfaces and regions shielded and exposed to the solar wind plasma flow. Our progress in the analysis and interpretation of the laboratory observations using simple analytic models and complex plasma simulation tools indicates that these models can be used to predict the expected properties of the lunar near-surface environment with increasing confidence. Based on our laboratory and theoretical efforts, we will also report on the status of
Grain charging in dusty plasmas (Invited)
NASA Astrophysics Data System (ADS)
Horanyi, M.
2013-12-01
Dusty plasmas represent the most general form of space, laboratory, and industrial plasmas. Interplanetary space, comets, planetary rings, asteroids, and aerosols in the atmosphere, are all examples where electrons, ions, and dust particles coexist. Dust particles immersed in plasmas and UV radiation collect electrostatic charges and respond to electromagnetic forces in addition to all the other forces acting on uncharged grains. Simultaneously, dust can alter its plasma environment. Dust particles in plasmas are unusual charge carriers. They are many orders of magnitude heavier than any other plasma particles, and they can have many orders of magnitude larger (negative or positive) time-dependent charges. The presence of dust can influence the collective plasma behavior, for example, by altering the traditional plasma wave modes and by triggering new types of waves and instabilities. This talk will focus on the charging processes, including the collection of electrons and ions in multi-species plasmas, and discuss the expected charge distribution on the dust particles as function of their size, and the dust density itself. Examples where these effects could result in novel plasma physics phenomena include Noctilucent clouds, and comets.
Scattering of radiation in collisionless dusty plasmas
Tolias, P.; Ratynskaia, S.
2013-04-15
Scattering of electromagnetic waves in collisionless dusty plasmas is studied in the framework of a multi-component kinetic model. The investigation focuses on the spectral distribution of the scattered radiation. Pronounced dust signatures are identified in the coherent spectrum due to scattering from the shielding cloud around the dust grains, dust acoustic waves, and dust-ion acoustic waves. The magnitude and shape of the scattered signal near these spectral regions are determined with the aid of analytical expressions and its dependence on the dust parameters is investigated. The use of radiation scattering as a potential diagnostic tool for dust detection is discussed.
Shock Propagation in Dusty Plasmas by MD Simulations
NASA Astrophysics Data System (ADS)
Marciante, Mathieu; Murillo, Michael
2014-10-01
The study of shock propagation has become a common way to obtain statistical information on a medium, as one can relate properties of the undisturbed medium to the shock dynamics through the Rankine-Hugoniot (R-H) relations. However, theoretical investigations of shock dynamics are often done through idealized fluid models, which mainly neglect kinetic properties of the medium constituents. Motivated by recent experimental results, we use molecular dynamics simulations to study the propagation of shocks in 2D-dusty plasmas, focusing our attention on the influence of kinetic aspects of the plasma, such as viscosity effects. This study is undertaken on two sides. On a first side, the shock wave is generated by an external electric field acting on the dust particles, giving rise to a shock wave as obtained in a laboratory experiment. On another side, we generate a shock wave by the displacement of a two-dimensional piston at constant velocity, allowing to obtain a steady-state shock wave. Experiment-like shock waves propagate in a highly non-steady state, what should ask for a careful application of the R-H relations in the context of non-steady shocks. Steady-state shock waves show an oscillatory pattern attributed to the dominating dispersive effect of the dusty plasma.
Electromagnetic waves in a polydisperse dusty plasma
Prudskikh, V. V.; Shchekinov, Yu. A.
2013-10-15
The properties of low-frequency electromagnetic waves in a polydisperse dusty plasma are studied. The dispersion relation for the waves propagating at an arbitrary angle to the external magnetic field is derived, with the coefficients explicitly determined by the dust-size distribution function. The dependence of wave dispersion on properties of the dust-size distribution function is analysed. It is shown that the cutoff for an oblique propagation in plasma with a wide scatter of dust sizes takes place at a much lower frequency than in a plasma with monosized dust particles. It is found that dispersion properties of a transversal magnetosonic wave mode around dust–cyclotron frequencies considerably differ from those in a plasma with monosized dust. In a plasma with low mass fraction of dust particles, the dispersion is smooth without the cutoff and the resonance intrinsic for a plasma with monosized dust. Increase of the dust fraction results in splitting of the dispersion curve on to two branches. Further increase of the dust fraction leads to emergence of the third branch located between the cutoffs and restricted from the lower and higher frequencies by two resonances. The dependence of the frequencies of cutoffs and resonances on the width of the dust-size distribution, its slope and the dust mass fraction are analysed. It is shown that the transparency frequency windows in a plasma with polydisperse dust are wider for transversal elecromagnetic waves, but narrower for longitudinal or oblique waves.
Propagation of electromagnetic waves in a weakly ionized dusty plasma
NASA Astrophysics Data System (ADS)
Jia, Jieshu; Yuan, Chengxun; Gao, Ruilin; Wang, Ying; Liu, Yaoze; Gao, Junying; Zhou, Zhongxiang; Sun, Xiudong; Wu, Jian; Li, Hui; Pu, Shaozhi
2015-11-01
Propagation properties of electromagnetic (EM) waves in weakly ionized dusty plasmas are the subject of this study. Dielectric relation for EM waves propagating at a weakly ionized dusty plasma is derived based on the Boltzmann distribution law while considering the collision and charging effects of dust grains. The propagation properties of EM energy in dusty plasma of rocket exhaust are numerically calculated and studied, utilizing the parameters of rocket exhaust plasma. Results indicate that increase of dust radius and density enhance the reflection and absorption coefficient. High dust radius and density make the wave hardly transmit through the dusty plasmas. Interaction enhancements between wave and dusty plasmas are developed through effective collision frequency improvements. Numerical results coincide with observed results by indicating that GHz band wave communication is effected by dusty plasma as the presence of dust grains significantly affect propagation of EM waves in the dusty plasmas. The results are helpful to analyze the effect of dust in plasmas and also provide a theoretical basis for the experiments.
Nonplanar Shock Waves in Dusty Plasmas
Mamun, A. A.; Shukla, P. K.
2011-11-29
Nonplanar (viz. cylindrical and spherical) electro-acoustic [dust-ion-acoustic (DIA) and dust-acoustic (DA)] shock waves have been investigated by employing the reductive perturbation method. The dust charge fluctuation (strong correlation among highly charged dust) is the source of dissipation, and is responsible for the formation of the DIA (DA) shock structures. The effects of cylindrical and spherical geometries on the time evolution of DIA and DA shock structures are examined and identified. The combined effects of vortex-like electron distribution and dust charge fluctuation (dust-correlation and effective dust-temperature) on the basic features of nonplanar DIA (DA) shock waves are pinpointed. The implications of our results in laboratory dusty plasma experiments are briefly discussed.
Nonplanar Shock Waves in Dusty Plasmas
NASA Astrophysics Data System (ADS)
Mamun, A. A.; Shukla, P. K.
2011-11-01
Nonplanar (viz. cylindrical and spherical) electro-acoustic [dust-ion-acoustic (DIA) and dust-acoustic (DA)] shock waves have been investigated by employing the reductive perturbation method. The dust charge fluctuation (strong correlation among highly charged dust) is the source of dissipation, and is responsible for the formation of the DIA (DA) shock structures. The effects of cylindrical and spherical geometries on the time evolution of DIA and DA shock structures are examined and identified. The combined effects of vortex-like electron distribution and dust charge fluctuation (dust-correlation and effective dust-temperature) on the basic features of nonplanar DIA (DA) shock waves are pinpointed. The implications of our results in laboratory dusty plasma experiments are briefly discussed.
Dusty plasma of the Enceladus plume
NASA Astrophysics Data System (ADS)
Yaroshenko, Victoria; Lühr, Hermann
2016-01-01
Geological active south-pole fractures of the icy moon Enceladus produce a specific region, a so-called plume that extends up to 1000 km into space. The main constituents of the plume are electrons, ions, water molecules, and charged nanograins, which are responsible for the unusual properties of this kind of low-temperature dusty plasma. The examples discussed represent our results in this field within the last few years, and mostly such cases were chosen, in which measurements of different Cassini instruments could be compared with theory or where the phenomenon has a diagnostic application. Dust charging, role of dust size distributions and dust charge fluctuations are discussed. The findings are used for interpretations of the Cassini Plasma Spectrometer data and improve constraints on the dust characteristics. Then the main forces and dust dynamics are discussed in conditions relevant for the near-Enceladus plasma. It is also examined how the charged dust can affect the plasma shielding length which is of importance for the reliable Cassini Langmuir probe measurements. Considering the dust grains as heavy negative ion species, the electric conductivity tensor is modified, whose elements are the key quantities for understanding the magnetic field perturbations registered by the Cassini Magnetometer during Enceladus flybys.
Dusty plasmas in the solar system
NASA Astrophysics Data System (ADS)
Goertz, C. K.
1989-05-01
The processes that lead to charging of dust grains in a plasma are briefly reviewed. Whereas for single grains the results have been long known, the reduction of the average charge on a grain by 'Debye screening' has only recently been discovered. This reduction can be important in the Jovian ring and in the rings of Uranus. The emerging field of gravitoelectrodynamics which deals with the motion of charged grains in a planetary magnetosphere is then reviewed. Important mechanisms for distributing grains in radial distance are due to stochastic fluctuations of the grain charge and a systematic variation due to motion through plasma gradients. The electrostatic levitation model for the formation of spokes is discussed, and it is shown that the radial transport of dust contained in the spokes may be responsible for the rich radial structure in Saturn's rings. Finally, collective effects in dusty plasmas are discussed which affect various waves, such as density waves in planetary rings and low-frequency plasma waves. The possibility of charged grains forming a Coulomb lattice is briefly described.
Ion- and dust-acoustic instabilities in dusty plasmas
NASA Technical Reports Server (NTRS)
Rosenberg, M.
1993-01-01
Dust ion-acoustic and dust-acoustic instabilities in dusty plasmas are investigated using a standard Vlasov approach. Possible applications of these instabilities to various cosmic environments, including protostellar clouds and planetary rings, are briefly discussed.
Kinetic theory of partially ionized complex (dusty) plasmas
Tsytovich, V.N.; De Angelis, U.; Ivlev, A.V.; Morfill, G.E.
2005-08-15
The general approach to the kinetic theory of complex (dusty) plasmas [Tsytovich and de Angelis, Phys. Plasmas 6, 1093 (1999)], which was formulated with the assumption of a regular (nonfluctuating) source of plasma particles, is reformulated to include ionization by electron impact on neutrals as the plasma source and the effects of collisions of ions and dust particles with neutrals.
Consistent description of kinetics and hydrodynamics of dusty plasma
Markiv, B.; Tokarchuk, M.; National University “Lviv Polytechnic,” 12 Bandera St., 79013 Lviv
2014-02-15
A consistent statistical description of kinetics and hydrodynamics of dusty plasma is proposed based on the Zubarev nonequilibrium statistical operator method. For the case of partial dynamics, the nonequilibrium statistical operator and the generalized transport equations for a consistent description of kinetics of dust particles and hydrodynamics of electrons, ions, and neutral atoms are obtained. In the approximation of weakly nonequilibrium process, a spectrum of collective excitations of dusty plasma is investigated in the hydrodynamic limit.
Theory of correlation effects in dusty plasmas
Avinash, K.
2015-03-15
A theory of correlation effects in dusty plasmas based on a suitably augmented Debye Huckel approximation is proposed. A model which takes into account the confinement of the dust within the plasma (by external fields) is considered. The dispersion relation of compressional modes with correlation effects is obtained. Results show that strong coupling effects may be subdominant even when Γ ≫ 1. Thus, in the limit Γ→0 and/or κ → ∞, one obtains the weakly coupled dust thermal mode. In the range of values of Γ ≫ 1, the strong coupling effects scale with κ instead of Γ; increasing Γ increases the dust acoustic waves phase velocity C{sub DAW} in this regime. In the limit Γ≫1,κ≪1, one obtains the weakly coupled dust acoustic wave. Only in the limit Γ≫1,κ≥1, one obtains strong coupling effects, e.g., the dust lattice waves (κ=a/λ{sub d}, a is the mean particle distance and λ{sub d} is the Debye length). Observations from a number of experiments are explained.
Dusty Plasma Effects in the Interplanetary Medium?
NASA Astrophysics Data System (ADS)
Mann, Ingrid; Issautier, Karine; Meyer-Vernet, Nicole; Le Chat, Gaétan; Czechowski, Andrzej; Zaslavsky, Arnaud; Zouganelis, Yannis; Belheouane, Soraya
Cosmic dust particles exist in a variety of compositions and sizes in the interplanetary medium. There is little direct information on the composition, but those interplanetary dust particles that are collected in the upper Earth’s atmosphere and can be studied in the laboratory typically have an irregular, sometimes porous structure on scales <100 nm. They contain magnesium-rich silicates and silicon carbide, iron-nickel and iron-sulfur compounds, calcium- and aluminum oxides, and chemical compounds that contain a large mass fraction of carbon (e.g. carbonaceous species). A fraction of the dust originates from comets, but because of their bulk material temperature of about 280 K near 1 AU, most icy compounds have disappeared. The dust particles are embedded in the solar wind, a hot plasma with at 1 AU kinetic temperatures around 100 000 K and flow direction nearly radial outward from the Sun at supersonic bulk velocities around 400 km/s. Since the dust particles carry an electric surface charge they are subject to electromagnetic forces and the nanodust particles are efficiently accelerated to velocities of order of solar wind speed. The acceleration of the nanodust is similar, but not identical to the formation of pick-up ions. The S/WAVES radio wave instrument on STEREO measured a flux of nanodust at 1 AU [1]. The nanodust probably forms in the region inward of 1 AU and is accelerated by the solar wind as discussed. We also discuss the different paths of dust - plasma interactions in the interplanetary medium and their observations with space experiments. Comparing these interactions we show that the interplanetary medium near 1 AU can in many cases be described as “dust in plasma" rather than "dusty plasma”. [1] S. Belheouane, N. Meyer-Vernet, K. Issautier, G. Le Chat, A. Zaslavsky, Y. Zouganelis, I. Mann, A. Czechowski: Dynamics of nanoparticles detected at 1 AU by S/WAVES onboard STEREO spacecraft, in this session.
Solitary kinetic Alfven waves in dusty plasmas
Li Yangfang; Wu, D. J.; Morfill, G. E.
2008-08-15
Solitary kinetic Alfven waves in dusty plasmas are studied by considering the dust charge variation. The effect of the dust charge-to-mass ratio on the soliton solution is discussed. The Sagdeev potential is derived analytically with constant dust charge and then calculated numerically by taking the dust charge variation into account. We show that the dust charge-to-mass ratio plays an important role in the soliton properties. The soliton solutions are comprised of two branches. One branch is sub-Alfvenic and the soliton velocity is obviously smaller than the Alfven speed. The other branch is super-Alfvenic and the soliton velocity is very close to or greater than the Alfven speed. Both compressive and rarefactive solitons can exist. For the sub-Alfvenic branch, the rarefactive soliton is bell-shaped and it is much narrower than the compressive one. However, for the super-Alfvenic branch, the compressive soliton is bell-shaped and narrower, and the rarefactive one is broadened. When the charge-to-mass ratio of the dust grains is sufficiently high, the width of the rarefactive soliton, in the super-Alfvenic branch, will broaden extremely and a electron depletion will be observed. It is also shown that the bell-shaped soliton can transition to a cusped structure when the velocity is sufficiently high.
Dust structurization observed in a dc glow discharge dusty plasma
NASA Astrophysics Data System (ADS)
Heinrich, Jonathon R.; Kim, Su-Hyun; Merlino, Robert L.
2010-11-01
Dusty plasmas, which are inherently open systems which require an ionization source to replenish the plasma absorbed on the grains, tend to exhibit self-organization. Various structures have been observed in dusty plasmas such as dust crystals, voids, and vortices. Due to the presence of drifting ions in dc discharge plasmas, spontaneously excited dust acoustic waves are also a common occurrence. By adjusting the discharge parameters we have observed a new phenomenon in dusty plasmas -- the spontaneous formation of three-dimensional stationary dust density structures. These structures appear as an ordered pattern consisting of alternating regions of high and low dust density arranged in a nested bowl-type configuration The stationary structure evolves from dust density waves that slow down as their wavelength decreases and eventually stop moving when the wavelength reaches some minimum size.
Space dusty plasmas: recent developments, advances, and unsolved problems
NASA Astrophysics Data System (ADS)
Popel, Sergey; Zelenyi, Lev
2016-07-01
The area of space dusty plasma research is a vibrant subfield of plasma physics that belongs to frontier research in physical sciences. This area is intrinsically interdisciplinary and encompasses astrophysics, planetary science, and atmospheric science. Dusty plasmas are ubiquitous in the universe; examples are proto-planetary and solar nebulae, molecular clouds, supernovae explosions, interplanetary medium, circumsolar rings, and asteroids. Within the solar system, we have planetary rings (e.g., Saturn and Jupiter), Martian atmosphere, cometary tails and comae, dust at the Moon, etc. Dust and dusty plasmas are also found in the vicinity of artificial satellites and space stations. The present review covers the main aspects of the area of space dusty plasma research. Emphasis is given to the description of dusty plasmas at the Moon which is important from the viewpoint of the future lunar missions and lunar observatory. This work was supported in part by the Presidium of the Russian Academy of Sciences (under Fundamental Research Program No. 7, "Experimental and Theoretical Study of the Solar System Objects and Stellar Planet Systems. Transient Explosion Processes in Astrophysics" and the Russian Foundation for Basic Research (Project No. 15-02-05627-a).
The physics and chemistry of dusty plasmas: A laboratory and theoretical investigation
NASA Technical Reports Server (NTRS)
Whipple, E. C.
1986-01-01
Theoretical work on dusty plasmas was conducted in three areas: collective effects in a dusty plasma, the role of dusty plasmas in cometary atmospheres, and the role of dusty plasmas in planetary atmospheres (particularly in the ring systems of the giant planets). Laboratory investigations consisted of studies of dust/plasma interactions and stimulated molecular excitation and infrared emission by charged dust grains. Also included is a list of current publications.
Visco-elastic effects in strongly coupled dusty plasmas
Bandyopadhyay, P.; Prasad, G.; Sen, A.; Kaw, P. K.
2008-09-07
We report on experimental evidence of visco-elastic effects in a strongly coupled dusty plasma through investigations of the propagation characteristics of low frequency dust acoustic waves and by excitations of transverse shear waves in a DC discharge Argon plasma.
Dusty Plasma Technology of DCM with Nanostructure Surface Layer Production
Gavrikov, A. V.; Ivanov, A. S.; Petrov, O. F.; Shulga, Yu. M.; Starostin, A. N.; Fortov, V. E.
2008-09-07
The technique of disperse composite material (DCM) production was developed. The technique based on using special dusty plasma trap in RF plasma, in which fine particles levitate and are exposed by the atomic beam. The two types of covering were obtained: ''cauliflower'' or smooth, depending on process condition.
The dielectric function of weakly ionized dusty plasmas
NASA Astrophysics Data System (ADS)
Li, Hui; Wu, Jian; Zhou, Zhong-Xiang; Yuan, Chengxun; Jia, Jieshu
2016-07-01
Using classical Boltzmann kinetic theory, the dielectric function of weakly ionized unmagnetized dusty plasma is derived. The elastic Coulomb collision and inelastic charging collision of electrons with charged dust particle as well as charge variation on dust surface are taken into account. The theoretical result is applied to analyze the propagation of electromagnetic wave in a dusty plasma. It is demonstrated that the additional collision mechanism provided by charged dust particle can significantly increase the absorbed power of electromagnetic wave. These increases are mainly determined by the dust radius, density, and the charge numbers on the dust surface. The obtained results will support an enhanced understanding of the wave propagation processes in space and laboratory dusty plasmas.
A brief review of dusty plasma effects in the solar system
Winske, D.
1997-08-01
Dusty plasmas are commonly found in the solar system and in the rest of space. In this paper we briefly describe some of the more common dusty plasmas: the rings of Saturn, dust tails of comets, dust streams from Jupiter, and noctilucent clouds in the upper atmosphere. We also discuss some of the theoretical issues related to grain charging, dust particle dynamics, waves in dusty plasmas, and dusty plasma crystals.
Solitary waves and double layers in a dusty electronegative plasma
Mamun, A. A.; Shukla, P. K.; Eliasson, B.
2009-10-15
A dusty electronegative plasma containing Boltzmann electrons, Boltzmann negative ions, cold mobile positive ions, and negatively charged stationary dust has been considered. The basic features of arbitrary amplitude solitary waves (SWs) and double layers (DLs), which have been found to exist in such a dusty electronegative plasma, have been investigated by the pseudopotential method. The small amplitude limit has also been considered in order to study the small amplitude SWs and DLs analytically. It has been shown that under certain conditions, DLs do not exist, which is in good agreement with the experimental observations of Ghim and Hershkowitz [Y. Ghim (Kim) and N. Hershkowitz, Appl. Phys. Lett. 94, 151503 (2009)].
Electro-acoustic shock structures in dusty plasmas
NASA Astrophysics Data System (ADS)
Mamun, A. A.; Mamun
2014-12-01
Two types of electro-acoustic shock structures, namely dust-ion-acoustic (DIA) and dust-acoustic (DA) shock structures, formed in two different kind of dusty plasma systems have been theoretically investigated. The sources of dissipation, which are responsible for the formation of DIA and DA shock structures in these dusty plasma systems, are identified. The conditions for the formation of these shock structures and their new basic features are pinpointed. The implications of the results in experimental observations are also discussed.
Kinetic theory of Jeans instability of a dusty plasma.
Pandey, B P; Lakhina, G S; Krishan, V
1999-12-01
A kinetic theory of the Jeans instability of a dusty plasma has been developed in the present work. The effect of grain charge fluctuations due to the attachment of electrons and ions to the grain surface has been considered in the framework of Krook's collisional model. We demonstrate that the grain charge fluctuations alter the growth rate of the gravitational collapse of the dusty plasma. The Jeans length has been derived under limiting cases, and its dependence on the attachment frequency is shown. In the absence of gravity, we see that the damping rate of the dust acoustic mode is proportional to the electron-dust collision frequency. PMID:11970688
Jeans instability of a dusty plasma with dust charge variations
Hakimi Pajouh, H. Afshari, N.
2015-09-15
The effect of the dust charge variations on the stability of a self-gravitating dusty plasma has been theoretically investigated. The dispersion relation for the dust-acoustic waves in a self-gravitating dusty plasma is obtained. It is shown that the dust charge variations have significant effects. It increases the growth rate of instability and the instability cutoff wavenumbers. It is found that by increasing the value of the ions temperature and the absolute value of the equilibrium dust charge, the cutoff wavenumber decreases and the stability region is extended.
Solitary waves in two-dimensional dusty plasma crystal: Effects of weak magnetic field
Ghosh, Samiran; Gupta, M. R.
2010-03-15
It is shown that in the presence of weak magnetic field, the dust lattice solitary wave in two-dimensional (2D) hexagonal dusty plasma crystal is governed by a gyration-modified 2D Korteweg-de Vries equation due to the action of Lorentz force on the dust particles. Numerical solutions reveal that only for weak magnetic field an apparently single hump solitary wave solution exist. But, for strong magnetic field dust lattice solitary wave becomes unstable showing repetitive solitary hump of increasing magnitude with time.
Electron energy distribution in a dusty plasma: analytical approach.
Denysenko, I B; Kersten, H; Azarenkov, N A
2015-09-01
Analytical expressions describing the electron energy distribution function (EEDF) in a dusty plasma are obtained from the homogeneous Boltzmann equation for electrons. The expressions are derived neglecting electron-electron collisions, as well as transformation of high-energy electrons into low-energy electrons at inelastic electron-atom collisions. At large electron energies, the quasiclassical approach for calculation of the EEDF is applied. For the moderate energies, we account for inelastic electron-atom collisions in the dust-free case and both inelastic electron-atom and electron-dust collisions in the dusty plasma case. Using these analytical expressions and the balance equation for dust charging, the electron energy distribution function, the effective electron temperature, the dust charge, and the dust surface potential are obtained for different dust radii and densities, as well as for different electron densities and radio-frequency (rf) field amplitudes and frequencies. The dusty plasma parameters are compared with those calculated numerically by a finite-difference method taking into account electron-electron collisions and the transformation of high-energy electrons at inelastic electron-neutral collisions. It is shown that the analytical expressions can be used for calculation of the EEDF and dusty plasma parameters at typical experimental conditions, in particular, in the positive column of a direct-current glow discharge and in the case of an rf plasma maintained by an electric field with frequency f=13.56MHz. PMID:26465570
Application of tomographic particle image velocimetry to complex (dusty) plasmas
Williams, Jeremiah
2011-11-29
Over the past decade, particle image velocimetry (PIV) techniques have been used to obtain detailed measurements of the thermal and transport properties of weakly-coupled dusty plasmas. This paper reports on the application of an extension of these techniques, tomographic PIV (tom-PIV), which provides an instantaneous volumetric measurement of the particle transport.
Beam-Plasma Interaction and Instabilities in a 2D Yukawa Plasma
NASA Astrophysics Data System (ADS)
Kyrkos, S.; Kalman, G.; Rosenberg, M.
2008-11-01
In a complex plasma, penetrating charged particle beams may lead to beam-plasma instabilities. When either the plasma, the beam, or both, are strongly interacting [1], the features of the instability are different from those in a weakly coupled plasma. We consider the case when a 2D dusty plasma forms a lattice, and the beam is moving in the lattice plane. Both the grains and the beam particles interact through a Yukawa potential; the beam particles are weakly coupled to each other and to the lattice. The system develops both a longitudinal and a transverse instability. Based on the phonon spectrum of a 2D hexagonal Yukawa lattice [2], we determine and compare the transverse and longitudinal growth rates. As a function of the wavenumber, the growth rates exhibit remarkable gaps, where no instability is excited. The gap locations are governed by the ratio of the lattice and the beam plasma frequencies. The behavior of the growth rates also depends on the direction of the beam and on the relationship between the beam speed and the longitudinal and transverse sound speeds. [1] GJ Kalman, M Rosenberg, JPA 36, 5963 (2003). [2] T Sullivan, GJ Kalman, S Kyrkos, P Bakshi, M Rosenberg, Z Donko, JPA 39, 4607 (2006).
Dusty (complex) plasmas: recent developments, advances, and unsolved problems
NASA Astrophysics Data System (ADS)
Popel, Sergey
The area of dusty (complex) plasma research is a vibrant subfield of plasma physics that be-longs to frontier research in physical sciences. This area is intrinsically interdisciplinary and encompasses astrophysics, planetary science, atmospheric science, magnetic fusion energy sci-ence, and various applied technologies. The research in dusty plasma started after two major discoveries in very different areas: (1) the discovery by the Voyager 2 spacecraft in 1980 of the radial spokes in Saturn's B ring, and (2) the discovery of the early 80's growth of contaminating dust particles in plasma processing. Dusty plasmas are ubiquitous in the universe; examples are proto-planetary and solar nebulae, molecular clouds, supernovae explosions, interplanetary medium, circumsolar rings, and asteroids. Within the solar system, we have planetary rings (e.g., Saturn and Jupiter), Martian atmosphere, cometary tails and comae, dust clouds on the Moon, etc. Close to the Earth, there are noctilucent clouds and polar mesospheric summer echoes, which are clouds of tiny (charged) ice particles that are formed in the summer polar mesosphere at the altitudes of about 82-95 km. Dust and dusty plasmas are also found in the vicinity of artificial satellites and space stations. Dust also turns out to be common in labo-ratory plasmas, such as in the processing of semiconductors and in tokamaks. In processing plasmas, dust particles are actually grown in the discharge from the reactive gases used to form the plasmas. An example of the relevance of industrial dusty plasmas is the growth of silicon microcrystals for improved solar cells in the future. In fact, nanostructured polymorphous sili-con films provide solar cells with high and time stable efficiency. These nano-materials can also be used for the fabrication of ultra-large-scale integration circuits, display devices, single elec-tron devices, light emitting diodes, laser diodes, and others. In microelectronic industries, dust has to be
Dressed soliton in quantum dusty pair-ion plasma
Chatterjee, Prasanta; Muniandy, S. V.; Wong, C. S.; Roy, Kaushik
2009-11-15
Nonlinear propagation of a quantum ion-acoustic dressed soliton is studied in a dusty pair-ion plasma. The Korteweg-de Vries (KdV) equation is derived using reductive perturbation technique. A higher order inhomogeneous differential equation is obtained for the higher order correction. The expression for a dressed soliton is calculated using a renormalization method. The expressions for higher order correction are determined using a series solution technique developed by Chatterjee et al. [Phys. Plasmas 16, 072102 (2009)].
Observation of the Taylor instability in a dusty plasma
Pacha, K. A.; Heinrich, J. R.; Kim, S.-H.; Merlino, R. L.
2012-01-15
Observations of the Taylor instability in a laboratory dusty plasma are presented. The dust cloud, formed in a dc argon glow-discharge plasma, is stratified into regions of high and low dust densities. The instability was triggered by a spontaneous intrusion of the low density dust fluid into the high density dust fluid at the interface. The instability in the dust fluid was phenomenologically similar to the hydrodynamic Taylor instability that occurs when a light fluid is accelerated into a heavy fluid.
Nanoparticle coagulation in fractionally charged and charge fluctuating dusty plasmas
Nunomura, Shota; Kondo, Michio; Shiratani, Masaharu; Koga, Kazunori; Watanabe, Yukio
2008-08-15
The kinetics of nanoparticle coagulation has been studied in fractionally charged and charge fluctuating dusty plasmas. The coagulation occurs when the mutual collision frequency among nanoparticles exceeds their charging and decharging/neutralization frequency. Interestingly, the coagulation is suppressed while a fraction (several percent) of nanoparticles are negatively charged in a plasma, in which stochastic charging plays an important role. A model is developed to predict a phase diagram of the coagulation and its suppression.
Ion-acoustic dressed solitons in a dusty plasma
Tiwari, R.S.; Mishra, M.K.
2006-06-15
Using the reductive perturbation method, equations for ion-acoustic waves governing the evolution of first- and second-order potentials in a dusty plasma including the dynamics of charged dust grains have been derived. The renormalization procedure of Kodama and Taniuti is used to obtain a steady state nonsecular solution of these equations. The variation of velocity and width of the Korteweg-de Vries (KdV) as well as dressed solitons with amplitude have been studied for different concentrations and charge multiplicity of dust grains. The higher-order perturbation corrections to the KdV soliton description significantly affect the characteristics of the solitons in dusty plasma. It is found that in the presence of positively charged dust grains the system supports only compressive solitons. However, the plasma with negatively charged dust grains can support compressive solitons only up to a certain concentration of dust. Above this critical concentration of negative charge, the dusty plasma can support rarefactive solitons. An expression for the critical concentration of negatively charged dust in terms of charge and mass ratio of dust grains with plasma ions is also derived.
Dust acoustic instability in a strongly coupled dusty plasma
NASA Astrophysics Data System (ADS)
Rosenberg, M.; Kalman, G. J.; Hartmann, P.; Goree, J.
2013-10-01
Dusty plasmas are plasmas containing charged micron to sub-micron size dust grains (solid particulates). Because the grains can be multiply charged and are much more massive than the ions, the presence of dust can lead to novel waves such as the dust acoustic wave, which is a compressional wave that can be excited by a flow of ions that is driven by an electric field. Moreover, the large dust charge can result in strong Coulomb coupling between the dust grains, where the electrostatic energy between neighboring grains is larger than their thermal (kinetic) energy. When the coupling between dust grains is strong, but not large enough for crystallization, the dust is in the strongly coupled liquid phase. This poster theoretically investigates the dust acoustic instability, which is driven by sub-thermal ion flow, in a three-dimensional dusty plasma in the strongly coupled liquid phase. It is found that strong coupling enhances the instability. The application is to microgravity experiments with dusty plasma planned for the PK-4 and PlasmaLab instruments, which are in development for the International Space Station. Microgravity conditions enable the preparation of dust clouds under these sub-thermal ion flow conditions by avoiding the need for strong electric fields to levitate the dust grains.
Twisted Landau damping rates in multi-component dusty plasmas
NASA Astrophysics Data System (ADS)
Ali, S.; Bukhari, S.; Mendonca, J. T.
2016-03-01
Keeping in view the kinetic treatment for plasma particles, the electrostatic twisted dust-acoustic (DA) and dust-ion-acoustic (DIA) waves are investigated in a collisionless unmagnetized multi-component dusty plasma, whose constituents are the electrons, singly ionized positive ions, and negatively charged massive dust particulates. With this background, the Vlasov-Poisson equations are coupled together to derive a generalized dielectric constant by utilizing the Laguerre-Gaussian perturbed distribution function and electrostatic potential in the paraxial limit. The dispersion and damping rates of twisted DA and DIA waves are analyzed with finite orbital angular momentum states in a multi-component dusty plasma. Significant modifications concerning the real wave frequencies and damping rates appeared with varying twisted dimensionless parameter and dust concentration. In particular, it is shown that dust concentration enhances the phase speed of the DIA waves in contrary to DA waves, whereas the impact of twisted parameter reduces the frequencies of both DA and DIA waves. The results should be useful for the understanding of particle transport and trapping phenomena caused by wave excitation in laboratory dusty plasmas.
Electrostatic twisted modes in multi-component dusty plasmas
NASA Astrophysics Data System (ADS)
Ayub, M. K.; Ali, S.; Ikram, M.
2016-01-01
Various electrostatic twisted modes are re-investigated with finite orbital angular momentum in an unmagnetized collisionless multi-component dusty plasma, consisting of positive/negative charged dust particles, ions, and electrons. For this purpose, hydrodynamical equations are employed to obtain paraxial equations in terms of density perturbations, while assuming the Gaussian and Laguerre-Gaussian (LG) beam solutions. Specifically, approximated solutions for potential problem are studied by using the paraxial approximation and expressed the electric field components in terms of LG functions. The energy fluxes associated with these modes are computed and corresponding expressions for orbital angular momenta are derived. Numerical analyses reveal that radial/angular mode numbers as well as dust number density and dust charging states strongly modify the LG potential profiles attributed to different electrostatic modes. Our results are important for understanding particle transport and energy transfer due to wave excitations in multi-component dusty plasmas.
Low frequency drift instabilities in a dusty plasma
Rosenberg, M.; Krall, N.A.
1996-02-01
Low frequency drift instabilities are investigated in a dusty magnetized plasma with negatively charged grains in which locally there is an electron density gradient which is opposite in sign to a dust density gradient. Frequencies less than the ion gyrofrequency but much larger than the dust gyrofrequency are considered. Two different equilibria are considered that are characterized by {rho}{sub {ital d}}{lt_or_gt}{ital L}{sub {ital nd}}, where {rho}{sub {ital d}} is the dust gyroradius and {ital L}{sub {ital nd}} is the dust density scale length. Instabilities analogous to the universal instability and to the lower-hybrid-drift instability (with the lower-hybrid frequency in this case associated with the dust) are investigated. Possible applications to dusty space plasmas such as the spoke regions of Saturn{close_quote}s B-ring are discussed. {copyright} {ital 1996 American Institute of Physics.}
Instability of dusty particle system in gas-discharge plasma
Filinov, V.S.; Petrov, O.F.; Fortov, V.E.; Molotkov, V.I.
2005-10-31
An effective anisotropic potential is proposed for the interaction between dust particles in a gas-discharge plasma. In addition to the Coulomb repulsion this potential takes into account attraction due to the spatial positive plasma charge originating from focusing of the ionic fluxes by dusty particles. The time evolution of the dust particle kinetic and potential energies from random initial configurations have been investigated by the Brownian dynamics method. Results of our simulation showed that the attraction between dusty particles can be the main physical reason of formation and decay of classical bound dust particle pairs and many particle complexes with low potential energy, while the kinetic energy (temperature) of unbound dust particles and particle oscillating in bound complexes may increase on three order as observed in experiments.
A Novel Experimental Setup to Investigate Magnetized Dusty Plasmas
NASA Astrophysics Data System (ADS)
Romero-Talamas, C. A.; Larocque, P.; Alvarez, J.; Sardin, J.
2013-10-01
Progress on the design and construction of a novel experimental setup to investigate dusty plasmas at the University of Maryland, Baltimore County (UMBC) is presented. The setup includes separation adjustability of discharge electrodes and their orientation with respect to gravity without breaking vacuum, and a pair of water-cooled coils to produce magnetic fields with strengths of up to several Tesla. The coils' orientation is also designed to be adjustable with respect to gravity. A pulse-forming network to power the coils with flattop times of several seconds is under design. The setup is mounted inside a large glass bell jar to provide wide optical access to the dusty plasmas, and to minimize interference of chamber walls and mounts with imposed electric or magnetic fields. Planned experiments include crystallization and wave propagation under strong magnetic fields.
Collective dynamics in strongly coupled dusty plasma medium
NASA Astrophysics Data System (ADS)
Das, Amita; Dharodi, Vikram; Tiwari, Sanat; Tiwari
2014-12-01
A simplified description of dynamical response of strongly coupled medium is desirable in many contexts of physics. The dusty plasma medium can play an important role in this regard due to its uniqueness, as its dynamical response typically falls within the perceptible grasp of human senses. Furthermore, even at room temperature and normal densities it can be easily prepared to be in a strongly coupled regime. A simplified phenomenological fluid model based on the visco - elastic behaviour of the medium is often invoked to represent the collective dynamical response of a strongly coupled dusty plasma medium. The manuscript reviews the role of this particular Generalized Hydrodynamic (GHD) fluid model in capturing the collective properties exhibited by the medium. In addition the paper also provides new insights on the collective behaviour predicted by the model for the medium, in terms of coherent structures, instabilities, transport and mixing properties.
Dusty Plasma in He-Ar Glow Discharge
Maiorov, S. A.; Ramazanov, T. S.; Dzhumagulova, K. N.; Dosbolayev, M. K.; Jumabekov, A. N.
2008-09-07
The paper reports on the first experiments with plasma-dust formations in dc gas discharge plasma for He-Ar mixture. It is shown that under the conventional conditions of the experiments with dusty structures in plasma, the choice of light and heavy gases for the mixture suppresses electron heating in electric field and results in a supersonic jet with high Mach numbers. Distribution functions for drifting ions in the gas mixture are calculated for various mixture concentrations, electric field strengths and gas pressures.
Shear waves in an inhomogeneous strongly coupled dusty plasma
Janaki, M. S.; Banerjee, D.; Chakrabarti, N.
2011-09-15
The properties of electrostatic transverse shear waves propagating in a strongly coupled dusty plasma with an equilibrium density gradient are examined using the generalized hydrodynamic (GH) equation. In the usual kinetic limit, the resulting equation has similarity to zero energy Schrodinger's equation. This has helped in obtaining some exact eigenmode solutions in both Cartesian and cylindrical geometries for certain nontrivial density profiles. The corresponding velocity profiles and the discrete eigenfrequencies are obtained for several interesting situations and their physics discussed.
Ion-Acoustic Waves in Self-Gravitaing Dusty Plasma
Kumar, Nagendra; Kumar, Vinod; Kumar, Anil
2008-09-07
The propagation and damping of low frequency ion-acoustic waves in steady state, unmagnetised, self-gravitating dusty plasma are studied taking into account two important damping mechanisms creation damping and Tromso damping. It is found that imaginary part of wave number is independent of frequency in case of creation damping. But when we consider the case of creation and Tromso damping together, an additional contribution to damping appears with the increase in frequency attributed to Tromso effect.
Nonlinear Generalized Hydrodynamic Wave Equations in Strongly Coupled Dusty Plasmas
Veeresha, B. M.; Sen, A.; Kaw, P. K.
2008-09-07
A set of nonlinear equations for the study of low frequency waves in a strongly coupled dusty plasma medium is derived using the phenomenological generalized hydrodynamic (GH) model and is used to study the modulational stability of dust acoustic waves to parallel perturbations. Dust compressibility contributions arising from strong Coulomb coupling effects are found to introduce significant modifications in the threshold and range of the instability domain.
FDTD Simulation on Terahertz Waves Propagation Through a Dusty Plasma
NASA Astrophysics Data System (ADS)
Wang, Maoyan; Zhang, Meng; Li, Guiping; Jiang, Baojun; Zhang, Xiaochuan; Xu, Jun
2016-08-01
The frequency dependent permittivity for dusty plasmas is provided by introducing the charging response factor and charge relaxation rate of airborne particles. The field equations that describe the characteristics of Terahertz (THz) waves propagation in a dusty plasma sheath are derived and discretized on the basis of the auxiliary differential equation (ADE) in the finite difference time domain (FDTD) method. Compared with numerical solutions in reference, the accuracy for the ADE FDTD method is validated. The reflection property of the metal Aluminum interlayer of the sheath at THz frequencies is discussed. The effects of the thickness, effective collision frequency, airborne particle density, and charge relaxation rate of airborne particles on the electromagnetic properties of Terahertz waves through a dusty plasma slab are investigated. Finally, some potential applications for Terahertz waves in information and communication are analyzed. supported by National Natural Science Foundation of China (Nos. 41104097, 11504252, 61201007, 41304119), the Fundamental Research Funds for the Central Universities (Nos. ZYGX2015J039, ZYGX2015J041), and the Specialized Research Fund for the Doctoral Program of Higher Education of China (No. 20120185120012)
Large amplitude ion-acoustic solitons in dusty plasmas
Tiwari, R. S.; Jain, S. L.; Mishra, M. K.
2011-08-15
Characteristics of ion-acoustic soliton in dusty plasma, including the dynamics of heavily charged massive dust grains, are investigated following the Sagdeev Potential formalism. Retaining fourth order nonlinearities of electric potential in the expansion of the Sagdeev Potential in the energy equation for a pseudo particle and integrating the resulting energy equation, large amplitude soliton solution is determined. Variation of amplitude (A), half width (W) at half maxima and the product P = AW{sup 2} of the Korteweg-deVries (KdV), dressed and large amplitude soliton as a function of wide range of dust concentration are numerically studied for recently observed parameters of dusty plasmas. We have also presented the region of existence of large amplitude ion-acoustic soliton in the dusty plasma by analyzing the structure of the pseudo potential. It is found that in the presence of positively charged dust grains, system supports only compressive solitons, on the other hand, in the presence of negatively charged dust grains, the system supports compressive solitons up to certain critical concentration of dust grains and above this critical concentration, the system can support rarefactive solitons also. The effects of dust concentration, charge, and mass of the dust grains, on the characteristics of KdV, dressed and large amplitude the soliton, i.e., amplitude (A), half width at half maxima (W), and product of amplitude (A) and half width at half maxima (P = AW{sup 2}), are discussed in detail.
Current driven instability in collisional dusty plasmas
NASA Astrophysics Data System (ADS)
Pandey, B. P.; Vladimirov, S. V.; Samarian, A.
2009-11-01
The current driven electromagnetic instability in a collisional, magnetized, dusty medium is considered in the present work. It is shown that in the presence of the magnetic field aligned current, the low-frequency waves in the medium can become unstable if the ratio of the current to the ambient field is larger than the light speed times the wave number. The growth rate of the instability depends upon the ratio of the Alfvén to the dust cyclotron frequency as well as on the ratio of the current density J to the dust charge density Zend, where Z is the number of electronic charge on the grain, e is the electron charge, and nd is the dust number density. The typical growth rate of this instability is on the order of Alfvén frequency which compares favorably with the electrostatic, cross-field current driven, Farley-Buneman instability and thus could play an important role in the Earth's ionosphere.
Electrostatic solitary waves in dusty pair-ion plasmas
Misra, A. P.; Adhikary, N. C.
2013-10-15
The propagation of electrostatic waves in an unmagnetized collisionless pair-ion plasma with immobile positively charged dusts is studied for both large- and small-amplitude perturbations. Using a two-fluid model for pair-ions, it is shown that there appear two linear ion modes, namely the “fast” and “slow” waves in dusty pair-ion plasmas. The properties of these wave modes are studied with different mass (m) and temperature (T) ratios of negative to positive ions, as well as the effects of immobile charged dusts (δ). For large-amplitude waves, the pseudopotential approach is performed, whereas the standard reductive perturbation technique is used to study the small-amplitude Korteweg-de Vries (KdV) solitons. The profiles of the pseudopotential, the large amplitude solitons as well as the dynamical evolution of KdV solitons, are numerically studied with the system parameters as above. It is found that the pair-ion plasmas with positively charged dusts support the propagation of solitary waves (SWs) with only the negative potential. The results may be useful for the excitation of SWs in laboratory dusty pair-ion plasmas, electron-free industrial plasmas as well as for observation in space plasmas where electron density is negligibly small compared to that of negative ions.
Self-diffusion in a stochastically heated two-dimensional dusty plasma
NASA Astrophysics Data System (ADS)
Sheridan, T. E.
2016-09-01
Diffusion in a two-dimensional dusty plasma liquid (i.e., a Yukawa liquid) is studied experimentally. The dusty plasma liquid is heated stochastically by a surrounding three-dimensional toroidal dusty plasma gas which acts as a thermal reservoir. The measured dust velocity distribution functions are isotropic Maxwellians, giving a well-defined kinetic temperature. The mean-square displacement for dust particles is found to increase linearly with time, indicating normal diffusion. The measured diffusion coefficients increase approximately linearly with temperature. The effective collision rate is dominated by collective dust–dust interactions rather than neutral gas drag, and is comparable to the dusty-plasma frequency.
Electrostatic solitary waves in a magnetized dusty plasma
Maharaj, S. K.; Bharuthram, R.; Singh, S. V.; Lakhina, G. S.; Pillay, S. R.
2008-11-15
The nonlinear evolution of driven low-frequency electrostatic waves is investigated in a three-component magnetized dusty plasma comprised of a warm dust fluid, electrons, and ions. Electrons as well as ions are considered to have Boltzmann distributions. The fluid equations for the dust along with the quasineutrality condition are used to obtain a single nonlinear differential equation for the electric field. Periodic solutions of the nonlinear differential equation yield sinusoidal, sawtooth and bipolar structures which are similar to nonlinear structures supported in electron-ion plasmas. Results of our findings are applied to Saturn's rings.
The width of the solitary wave in dusty plasma
NASA Astrophysics Data System (ADS)
Malekolkalami, Behrooz; Alipanah, Amjad
2016-01-01
The Sagdeev potential method is employed to compute the width of the ion-acoustic solitary wave propagated in a dusty plasma containing three components (dust-ion-electron). The results indicate that the width is a continuous function over the allowable ranges of plasma parameters. The complexity of the resulting equations is an obstacle to the expression of the width function in an explicit form in terms of the parameters. Thus, computer algebra is needed to plot the graph of the width function versus the parameters, which helps us to understand the width changes as the parameters change.
Ion sphere model for Yukawa systems (dusty plasmas)
NASA Astrophysics Data System (ADS)
Khrapak, S. A.; Khrapak, A. G.; Ivlev, A. V.; Thomas, H. M.
2014-12-01
Application of the ion sphere model (ISM), well known in the context of the one-component-plasma, to estimate thermodynamic properties of model Yukawa systems is discussed. It is shown that the ISM approximation provides fairly good estimate of the internal energy of the strongly coupled Yukawa systems, in both fluid and solid phases. Simple expressions for the excess pressure and isothermal compressibility are derived, which can be particularly useful in connection to wave phenomena in strongly coupled dusty plasmas. It is also shown that in the regime of strong screening a simple consideration of neighboring particles interactions can be sufficient to obtain quite accurate estimates of thermodynamic properties of Yukawa systems.
On vortex dust structures in magnetized dusty plasmas
Nebbat, E.; Annou, R.
2010-09-15
To explain the generation of vortex patterns of dust grains in a magnetized dusty plasma [Huang et al., Plasma Sci. Technol. 9, 1 (2007)], a time dependent nonlinear model that describes vortices as a result of an instability is proposed. Grain-grain as well as grain-ion interactions, particle attachment, and grains drift and diffusion are key elements in the present model. It is found that the latter reproduces the experimental results quite well, whereas the stability analysis shows that the vortex core is grain size dependent.
Formation Of Voids In Dusty Lorentzian Plasma
Bahamida, S.; Annou, K.; Annou, R.
2008-09-07
We study the possibility of formation of voids in Lorentzian plasmas containing of dust particles obeying to vortex-like velocity distribution. The size of the void is found to be ion spectral index dependent.
A 1-D dusty plasma photonic crystal
Mitu, M. L.; Ticoş, C. M.; Toader, D.; Banu, N.; Scurtu, A.
2013-09-21
It is demonstrated numerically that a 1-D plasma crystal made of micron size cylindrical dust particles can, in principle, work as a photonic crystal for terahertz waves. The dust rods are parallel to each other and arranged in a linear string forming a periodic structure of dielectric-plasma regions. The dispersion equation is found by solving the waves equation with the boundary conditions at the dust-plasma interface and taking into account the dielectric permittivity of the dust material and plasma. The wavelength of the electromagnetic waves is in the range of a few hundred microns, close to the interparticle separation distance. The band gaps of the 1-D plasma crystal are numerically found for different types of dust materials, separation distances between the dust rods and rod diameters. The distance between levitated dust rods forming a string in rf plasma is shown experimentally to vary over a relatively wide range, from 650 μm to about 1350 μm, depending on the rf power fed into the discharge.
Small Dust Cluster Probes within a Dusty Plasma
NASA Astrophysics Data System (ADS)
Kong, Jie; Qiao, Ke; Matthews, Lorin; Hyde, Truell
2014-10-01
Small-number dust particle clusters are often seen in dusty plasmas. Interestingly, such clusters can often be used as in-situ probes providing plasma diagnostics. The number of dust particles, as well as the cluster size and shape, can be easily controlled employing a glass box placed on the powered lower electrode within a GEC rf reference chamber to provide confinement of the dust. Adjusting the rf power alters the plasma conditions creating structural changes within the cluster. This effect can be used to probe the relationship between the rf power and other plasma parameters of interest. This experiment employs the sloshing and breathing modes of small cluster oscillations to examine the relationship between the system's rf power and the plasma screening length inside the glass box as well as determine the particle charge. Experimental results indicate that both the screening length and the dust charge decrease as the rf power inside the box increases.
Coulomb Crystals in Cylindrical Dusty Plasmas under Gravity/Microgravity
NASA Astrophysics Data System (ADS)
Takahashi, Kazuo; Totsuji, Hiroo; Adachi, Satoshi
2014-10-01
Coulomb crystals of dusty plasmas have been studied under microgravity with utilities boarding on the International Space Station in a joint Russian/German research project. Dynamics of the Coulomb crystals in cylindrical plasmas is investigated with the apparatus of PK-4 being launched till the end of 2014. A science team in Japan studied the cylindrical dusty plasmas to contribute to the project with the PK-4J modified original for microgravity experiments of parabolic flights in Japan. In the experiments, the dust particles distributed at the off-centered position close to the bottom in balancing of gravity. Under microgravity, they changed the distribution and formed a Coulomb crystal around the center axis in the plasmas. Several particles arranged in a line parallel to the axis, and the lines piled up to a bundle. Spatial distribution of the dust particles affects on plasma parameters of ion density and electron temperature. Structures of the Coulomb crystals connected to the parameters are discussed. The present study were supported by JAXA and Diamond Air Service.
Nonlinear inertial Alfven wave in dusty plasmas
Mahmood, S.; Saleem, H.
2011-11-29
Solitary inertial Alfven wave in the presence of positively and negatively charged dust particles is studied. It is found that electron density dips are formed in the super Alfvenic region and wave amplitude is increased for the case of negatively charged dust particles in comparison with positively charged dust particles in electron-ion plasmas.
Waterspout - an Atmospheric Aerosol Dusty Plasma
Rantsev-Kartinov, V.A.
2005-10-31
An aerosol -- capillary electrostatic model of a waterspout is submitted. The waterspout is treated as a long-living filament of aerosol plasma, which is formed at electric breakdown of interval between a charged cloud and a vertically floating cylinder, which is individual block of ocean's skeletal structures of revealed recently by author.
Nonlinear screening of dust grains and structurization of dusty plasma
Tsytovich, V. N. Gusein-zade, N. G.
2013-07-15
A review of theoretical ideas on the physics of structurization instability of a homogeneous dusty plasma, i.e., the formation of zones with elevated and depressed density of dust grains and their arrangement into different structures observed in laboratory plasma under microgravity conditions, is presented. Theoretical models of compact dust structures that can form in the nonlinear stage of structurization instability, as well as models of a system of voids (both surrounding a compact structure and formed in the center of the structure), are discussed. Two types of structures with very different dimensions are possible, namely, those smaller or larger than the characteristic mean free path of ions in the plasma flow. Both of them are characterized by relatively regular distributions of dust grains; however, the first ones usually require external confinement, while the structures of the second type can be self-sustained (which is of particular interest). In this review, they are called dust clusters and self-organized dust structures, respectively. Both types of the structures are characterized by new physical processes that take place only in the presence of the dust component. The role of nonlinearities in the screening of highly charged dust grains that are often observed in modern laboratory experiments turns out to be great, but these nonlinearities have not received adequate study as of yet. Although structurization takes place upon both linear and nonlinear screening, it can be substantially different under laboratory and astrophysical conditions. Studies on the nonlinear screening of large charges in plasma began several decades ago; however, up to now, this effect was usually disregarded when interpreting the processes occurring in laboratory dusty plasma. One of the aims of the present review was to demonstrate the possibility of describing the nonlinear screening of individual grains and take it into account with the help of the basic equations for the
Tiling analysis of melting in strongly-coupled dusty plasma*
NASA Astrophysics Data System (ADS)
Suranga Ruhunusiri, W. D.; Feng, Yan; Liu, Bin; Goree, John
2010-11-01
A dusty plasma is an ionized gas containing micron-size particles of solid matter, which collect electrons and ions and become negatively charged. Due to large Coulomb interparticle potential energies, the microparticles represent a strongly-coupled plasma. In the absence of an external disturbance, the microparticles self-organize, arranging themselves in a crystalline lattice, due to their Coulomb interaction. If kinetic energy is added, the arrangement of microparticles becomes disordered, like atoms in a liquid. This melting process can be characterized by a proliferation of defects, which previous experimenters measured using Voronoi analysis. Here we use another method, tiling [1] to quantify defects. We demonstrate this method, which until now has been used only in simulations, in a dusty plasma experiment. A single layer of 4.83 μm polymer microparticles was electrically levitated in a glow discharge argon plasma. The lattice was melted by applying random kicks to the micoparticles from rastered laser beams. We imaged the particle positions and computed the corresponding tiling for both the crystalline lattice and liquid states. [1] Matthew A. Glaser, Phys. Rev A 41, 4585 (1990) ^*Work supported by NSF and NASA.
The acoustic instabilities in magnetized collisional dusty plasmas
Pandey, B. P.; Vladimirov, S. V.; Dwivedi, C. B.
2014-09-15
The present work investigates the wave propagation in collisional dusty plasmas in the presence of electric and magnetic field. It is shown that the dust ion-acoustic waves may become unstable to the reactive instability whereas dust-acoustic waves may suffer from both reactive and dissipative instabilities. If the wave phase speed is smaller than the plasma drift speed, the instability is of reactive type whereas in the opposite case, the instability becomes dissipative in nature. Plasma in the vicinity of dust may also become unstable to reactive instability with the instability sensitive to the dust material: dielectric dust may considerably quench this instability. This has implications for the dust charging and the use of dust as a probe in the plasma sheath.
Dust acoustic waves in strongly coupled dusty plasmas
Rosenberg, M. Kalman, G.
1997-12-01
Dust grains, or solid particles of {mu}m to sub-{mu}m sizes, are observed in various low-temperature laboratory plasmas such as process plasmas and dust plasma crystals. The massive dust grains are generally highly charged, and it has been shown within the context of standard plasma theory that their presence can lead to new low-frequency modes such as dust acoustic waves. In certain laboratory plasmas, however, the dust may be strongly coupled, as characterized by the condition {Gamma}{sub d}=Q{sub d}{sup 2}exp({minus}d/{lambda}{sub D})/dT{sub d}{ge}1, where Q{sub d} is the dust charge, d is the intergrain spacing, T{sub d} is the dust thermal energy, and {lambda}{sub D} is the plasma screening length. This paper investigates the dispersion relation for dust acoustic waves in a strongly coupled dusty plasma comprised of strongly coupled negatively charged dust grains, and weakly correlated classical ions and electrons. The dust grains are assumed to interact via a (screened Coulomb) Yukawa potential. The strongly coupled gas phase (liquid phase) is considered, and a quasilocalized charge approximation scheme is used, generalized to take into account electron and/or ion screening of the dust grains. The scheme relates the small-k dispersion to the total correlation energy of the system, which is obtained from the results of published numerical simulations. Some effects of collisions of charged particles with neutrals are taken into account. Applications to laboratory dusty plasmas are discussed. {copyright} {ital 1997} {ital The American Physical Society}
The Interaction of Terahertz Waves and a Dusty Plasma Slab with Epstein Distribution
NASA Astrophysics Data System (ADS)
Wang, Maoyan; Xu, Zhitao; Dong, Yuliang; Xu, Jun; Zhang, Meng
2016-01-01
The Auxiliary Differential Equation Finite Difference Time Domain (ADE-FDTD) method is applied to study the electromagnetic scattering of a dusty plasma sheath with Epstein distribution. The charging response factor of dust particles and angular plasma frequency of the dusty plasma are functions of space-varying electron density with an Epstein profile. The verification of the numerical ADE-FDTD algorithm for the dusty plasma is given. The propagation properties of Terahertz (THz) waves through a dusty plasma slab affected by the characteristic parameter and modulation factor of the Epstein distribution are discussed. The absorption coefficients of the slab influenced by the electron density, density of dust particles, and effective collision frequency are studied. It is shown that Terahertz waves may be an efficient tool for high density dusty plasmas detection and diagnostics.
nMHDust: A 4-Fluid Partially Ionized Dusty Plasma Code
NASA Astrophysics Data System (ADS)
Lazerson, Samuel
2008-11-01
nMHDust is a next generation 4-fluid partially ionized magnetized dusty plasma code, treating the inertial dynamics of dust, ion and neutral components. Coded in ANSI C, the numerical method is based on the MHDust 3-fluid fully ionized dusty plasma code. This code expands the features of the MHDust code to include ionization/recombination effects and the netCDF data format. Tests of this code include: ionization instabilities, wave mode propagation (electromagnetic and acoustic), shear-flow instabilities, and magnetic reconnection. Relevant parameters for the space environment are considered, allowing a comparison to be made with previous dusty plasma codes (MHDust and DENISIS). The utility of the code is expanded through the possibility of a small dust mass. This allows nMHDust to be used as a 2-ion plasma code. nMHDust completes the array of fluid dusty plasma codes available for numerical investigations into nonlinear phenomena in the field of astrophysical dusty plasmas.
Nonlinear Landau damping of transverse electromagnetic waves in dusty plasmas
Tsintsadze, N. L.; Chaudhary, Rozina; Shah, H. A.; Murtaza, G.
2009-04-15
High-frequency transverse electromagnetic waves in a collisionless isotropic dusty plasma damp via nonlinear Landau damping. Taking into account the latter we have obtained a generalized set of Zakharov equations with local and nonlocal terms. Then from this coupled set of Zakharov equations a kinetic nonlinear Schroedinger equation with local and nonlocal nonlinearities is derived for special cases. It is shown that the modulation of the amplitude of the electromagnetic waves leads to the modulation instability through the nonlinear Landau damping term. The maximum growth rate is obtained for the special case when the group velocity of electromagnetic waves is close to the dust acoustic velocity.
Nonlinear wave propagation in a strongly coupled collisional dusty plasma
Ghosh, Samiran; Gupta, Mithil Ranjan; Chakrabarti, Nikhil; Chaudhuri, Manis
2011-06-15
The propagation of a nonlinear low-frequency mode in a strongly coupled dusty plasma is investigated using a generalized hydrodynamical model. For the well-known longitudinal dust acoustic mode a standard perturbative approach leads to a Korteweg-de Vries (KdV) soliton. The strong viscoelastic effect, however, introduced a nonlinear forcing and a linear damping in the KdV equation. This novel equation is solved analytically to show a competition between nonlinear forcing and dissipative damping. The physical consequence of such a solution is also sketched.
Nonlinear wave propagation in a strongly coupled collisional dusty plasma.
Ghosh, Samiran; Gupta, Mithil Ranjan; Chakrabarti, Nikhil; Chaudhuri, Manis
2011-06-01
The propagation of a nonlinear low-frequency mode in a strongly coupled dusty plasma is investigated using a generalized hydrodynamical model. For the well-known longitudinal dust acoustic mode a standard perturbative approach leads to a Korteweg-de Vries (KdV) soliton. The strong viscoelastic effect, however, introduced a nonlinear forcing and a linear damping in the KdV equation. This novel equation is solved analytically to show a competition between nonlinear forcing and dissipative damping. The physical consequence of such a solution is also sketched. PMID:21797497
Evolution of an expanding dusty plasma with negative ions
Kechouri, B.; Djebli, M.
2006-11-15
The dusty plasma radial expansion is studied in the case of a spherical as well as cylindrical configuration. The effect of negative ions is introduced through the dust charge fluctuation equation. Electrons, positive, and negative ions are modelled by the Boltzmann distribution function and the dust grains by fluid equations. Using the self-similar theory, the nonlinear set of differential equations is solved numerically. It is found that the dust charge presents a critical value which depends on the negative ion species type. It is also found that the dust expansion ends earlier and the lighter particle densities profiles depend on the dust initial charge.
High frequency drift instabilities in a dusty plasma
NASA Technical Reports Server (NTRS)
Rosenberg, M.; Krall, N. A.
1994-01-01
High frequency drift instabilities with omega(sub ce) much greater than omega which is greater than omega(sub ci) are investigated in a dusty magnetized plasma in which locally there is an electron density gradient which is opposite in sign to a dust density gradient. Two different equilibria are considered, characterized by rho(sub d) greater than L(sub d) and less than L(sub d), where rho(sub d) is the dust gyroradius and L(sub nd) is the dust density scale length. Possible application to Saturn's F-ring is discussed.
Radial Distributions of Dusty Plasma Parameters in a Glow Discharge
Fedoseev, A. V.; Sukhinin, G. I.
2011-11-29
A self-consistent model for radial distributions of dusty plasma parameters in a DC glow discharge based on the non-local Boltzmann equation for EEDF, the drift-diffusion equation for ions, and the Poisson equation for self-consistent electric field is presented. The results show that for the case of high dust particles density when the recombination of electrons and ions exceeds the ionization near the tube axis, radial electron and ion fluxes change their direction toward the center of the tube, and the radial electric field is reversed.
Landau damping in a multi-component dusty plasma
Zhang, Heng; Yang, Yang; Zhang, Jie; Hong, Xue-Ren; Lin, Mai-Mai; Qi, Xin E-mail: duanws@nwnu.edu.cn; Duan, Wen-Shan E-mail: duanws@nwnu.edu.cn; Yang, Lei
2014-11-15
Effect of the dust size distribution on the landau damping and the wave frequency is studied in the present paper. It is found that wave frequency increases as either the difference between the largest and the smallest dust size increases or the wave number increases. It seems that wave frequency is smaller for dusty plasma whose density of the smaller grains is larger than that of the larger ones, while it is larger in the opposite case. The effect of the dust size distribution can increase the Landau damping in the cases where the temperature of the dust grains is small enough or high enough.
Dusty Plasma Structures in Gas Mixtures
Popova, D. V.; Antipov, S. N.; Petrov, O. F.; Fortov, V. E.
2008-09-07
The possibility of attainment of large Mach numbers is analyzed for the case of heavy ions drifting in a light gas. Under conditions of typical experiments with dust structures in plasmas, the use of the mixture of light and heavy gases is shown to make it possible to suppress the ion heating in the electric field and to form supersonic flows characterized by large Mach numbers. The drift of krypton ions in helium is considered as an example. Experiments with dc glow discharge at 1-10% of Kr show that the transition to the discharge in mixture leads to increase of interaction anisotropy and reinforcement of coupling of dust particles in the direction of ion drift. On the other hand, under certain conditions the phenomenon of abnormal 'heating' of dust particles was observed when the particles can obtain high kinetic energy which is several orders of magnitude higher than typical.
Diagnostics for transport phenomena in strongly coupled dusty plasmas
NASA Astrophysics Data System (ADS)
Goree, J.; Liu, Bin; Feng, Yan
2013-12-01
Experimental methods are described for determining transport coefficients in a strongly coupled dusty plasma. A dusty plasma is a mixture of electrons, ions and highly charged microspheres. Due to their large charges, the microspheres are a strongly coupled plasma, and they arrange themselves like atoms in a crystal or liquid. Using a video microscopy diagnostic, with laser illumination and a high speed video camera, the microspheres are imaged. Moment-method image analysis then yields the microspheres' positions and velocities. In one approach, these data in the particle paradigm are converted into the continuum paradigm by binning, yielding hydrodynamic quantities like number density, flow velocity and temperature that are recorded on a grid. To analyze continuum data for two-dimensional laboratory experiments, they are fit to the hydrodynamic equations, yielding the transport coefficients for shear viscosity and thermal conductivity. In another approach, the original particle data can be used to obtain the diffusion and viscosity coefficients, as is discussed in the context of future three-dimensional microgravity experiments.
Design and Assembly of the Magnetized Dusty Plasma Experiment (MDPX)
NASA Astrophysics Data System (ADS)
Fisher, Ross; Artis, Darrick; Lynch, Brian; Wood, Keith; Shaw, Joseph; Gilmore, Kevin; Robinson, Daniel; Polka, Christian; Konopka, Uwe; Thomas, Edward; Merlino, Robert; Rosenberg, Marlene
2013-10-01
Over the last two years, the Magnetized Dusty Plasma Experiment (MDPX) has been under construction at Auburn University. This new research device, whose assembly will be completed in late Summer, 2013, uses a four-coil, superconducting, high magnetic field system (|B | >= 4 Tesla) to investigate the confinement, charging, transport, and instabilities in a dusty plasma. A new feature of the MDPX device is the ability to operate the magnetic coils independently to allow a variety of magnetic configurations from highly uniform to quadrapole-like. Envisioned as a multi-user facility, the MDPX device features a cylindrical vacuum vessel whose primary experimental region is an octagonal chamber that has a 35.5 cm inner diameter and is 19 cm tall. There is substantial diagnostics and optical access through eight, 10.2 cm × 12.7 cm side ports. The chamber can also be equipped with two 15.2 cm diameter, 76 cm long extensions to allow long plasma column experiments, particularly long wavelength dust wave studies. This presentation will discuss the final design, assembly, and installation of the MDPX device and will describe its supporting laboratory facility. This work is supported by a National Science Foundation - Major Research Instrumentation (NSF-MRI) award, PHY-1126067.
Propagation of electromagnetic waves in a weak collisional and fully ionized dusty plasma
NASA Astrophysics Data System (ADS)
Jia, Jieshu; Yuan, Chengxun; Liu, Sha; Yue, Feng; Gao, Ruilin; Wang, Ying; Zhou, Zhong-Xiang; Wu, Jian; Li, Hui
2016-04-01
The propagation properties of electromagnetic (EM) waves in fully ionized dusty plasmas is the subject of this study. The dielectric relationships for EM waves propagating in a fully ionized dusty plasma was derived from the Boltzmann distribution law, taking into consideration the collision and charging effects of the dust grains. The propagation properties of the EM waves in a dusty plasma were numerically calculated and studied. The study results indicated that the dusty grains with an increased radius and charge were more likely to impede the penetration of EM waves. Dust grains with large radii and high charge cause the attenuation of the EM wave in the dusty plasma. The different density of the dust in the plasma appeared to have no obvious effect on the transmission of the EM waves. The propagation of the EM waves in a weakly ionized dusty plasma varies from that in a fully ionized dusty plasma. The results are helpful to analyze the effects of dust in dusty plasmas and also provide a theoretical basis for future studies.
Final Progress Report for Ionospheric Dusty Plasma In the Laboratory [Smokey Plasma
Robertson, Scott
2010-09-28
“Ionospheric Dusty Plasma in the Laboratory” is a research project with the purpose of finding and reproducing the characteristics of plasma in the polar mesosphere that is unusually cold (down to 140 K) and contains nanometer-sized dust particles. This final progress report summarizes results from four years of effort that include a final year with a no-cost extension.
Numerical Experiments In Strongly Coupled Complex (Dusty) Plasmas
NASA Astrophysics Data System (ADS)
Hou, L. J.; Ivlev A.; Hubertus M. T.; Morfill, G. E.
2010-07-01
Complex (dusty) plasma is a suspension of micron-sized charged dust particles in a weakly ionized plasma with electrons, ions, and neutral atoms or molecules. Therein, dust particles acquire a few thousand electron charges by absorbing surrounding electrons and ions, and consequently interact with each other via a dynamically screened Coulomb potential while undergoing Brownian motion due primarily to frequent collisions with the neutral molecules. When the interaction potential energy between charged dust particles significantly exceeds their kinetic energy, they become strongly coupled and can form ordered structures comprising liquid and solid states. Since the motion of charged dust particles in complex (dusty) plasmas can be directly observed in real time by using a video camera, such systems have been generally regarded as a promising model system to study many phenomena occurring in solids, liquids and other strongly-coupled systems at the kinetic level, such as phase transitions, transport processes, and collective dynamics. Complex plasma physics has now grown into a mature research field with a very broad range of interdisciplinary facets. In addition to usual experimental and theoretical study, computer simulation in complex plasma plays an important role in bridging experimental observations and theories and in understanding many interesting phenomena observed in laboratory. The present talk will focus on a class of computer simulations that are usually non-equilibrium ones with external perturbation and that mimic the real complex plasma experiments (i. e., numerical experiment). The simulation method, i. e., the so-called Brownian Dynamics methods, will be firstly reviewed and then examples, such as simulations of heat transfer and shock wave propagation, will be present.
Ghosh, Samiran
2014-09-01
The propagation of a nonlinear low-frequency mode in two-dimensional (2D) monolayer hexagonal dusty plasma crystal in presence of external magnetic field and dust-neutral collision is investigated. The standard perturbative approach leads to a 2D Korteweg-de Vries (KdV) soliton for the well-known dust-lattice mode. However, the Coriolis force due to crystal rotation and Lorentz force due to magnetic field on dust particles introduce a linear forcing term, whereas dust-neutral drag introduce the usual damping term in the 2D KdV equation. This new nonlinear equation is solved both analytically and numerically to show the competition between the linear forcing and damping in the formation of quasilongitudinal soliton in a 2D strongly coupled complex (dusty) plasma. Numerical simulation on the basis of the typical experimental plasma parameters and the analytical solution reveal that the neutral drag force is responsible for the usual exponential decay of the soliton, whereas Coriolis and/or Lorentz force is responsible for the algebraic decay as well as the oscillating tail formation of the soliton. The results are discussed in the context of the plasma crystal experiment. PMID:25314548
Heat transport in a two-dimensional complex (dusty) plasma at melting conditions
NASA Astrophysics Data System (ADS)
Nosenko, V.; Ivlev, A. V.; Zhdanov, S.; Morfill, G.; Goree, J.; Piel, A.
2007-11-01
The heat transport in a two-dimensional complex (dusty) plasma undergoing a phase transition was studied experimentally. A single layer of highly charged polymer microspheres was suspended in a plasma sheath. In the absence of manipulation, the suspension forms a 2D triangular lattice. To melt this lattice and form a liquid, we used a laser-heating method. Two focused laser beams were moved rapidly around in the monolayer. The kinetic temperature of the particles increased with the laser power applied, and above a threshold a melting transition occurred. We used video microscopy for direct imaging and particle tracking. The spatial profiles of the particle kinetic temperature were calculated. Using the heat transport equation with an additional term to account for the energy dissipation due to the gas drag, we analyzed the temperature profiles to find a thermal conductivity, which did not depend on temperature.
Early time evolution of artificially created dusty space plasmas
NASA Astrophysics Data System (ADS)
Scales, Wayne
An alternate approach to studying natural dust layers in the earth's upper atmosphere is to perform active space experiments in which a dust cloud is created in a controlled manner. Its evolution can then be more carefully observed and studied and then compared to characteristics of natural dust clouds. Such space experiments are currently under development are planned for the near future. Several important issues to be investigated include dust charging processes, plasma flows, electrodynamic structure, plasma irregularities, and coupling between the neutral components of the upper atmosphere and the dust clouds. Also possibilities of remote sensing plasma processes in these clouds through radar measurements will be studied. This talk will address some of the physical processes expected to be important during the early time phase after creation of an artificial dust cloud in the earth's ionosphere. Of principal importance will be the production of plasma irregularities which may lead to radar echoes and the possibility of their relationship to well known radar echoes observed from natural dusty space plasmas. First, a plasma model will be described that may be used for investigating early time evolution after expansion of an artificial dust cloud across the magnetic field in the ionosphere. This model will then be used to investigate the electrodynamics and possible plasma irregularity generation mechanisms after creation of an artificial dust cloud. Finally, possibilities of radar signatures observed from the dust cloud will be considered.
Dusty plasma in the region of the lunar terminator
NASA Astrophysics Data System (ADS)
Popel, S. I.; Zelenyi, L. M.; Atamaniuk, B.
2016-05-01
Dusty plasma in the region of the lunar terminator is considered. It is shown that, in this region, a structure resembling a plasma sheath forms near the lunar surface. This sheath creates a potential barrier, due to which electrons over the illuminated part of the Moon are confined by electrostatic forces. The width of the sheath-like structure is on the order of the ion Debye length. In this structure, significant (about several hundred V/m) electric fields arise, which lift charged micron-size dust grains to heights of several tens of centimeters. The suggested effect may be used to explain the glow observed by the Surveyor spacecraft over the lunar terminator.
Dressed ion-acoustic solitons in magnetized dusty plasmas
El-Labany, S. K.; El-Shamy, E. F.; El-Warraki, S. A.
2009-01-15
In the present research paper, the characteristics of ion acoustic solitary waves are investigated in hot magnetized dusty plasmas consisting of negatively charged dust grains, positively charged ion fluid, and isothermal electrons. Applying a reductive perturbation theory, a nonlinear Korteweg-de Vries (KdV) equation for the first-order perturbed potential and a linear inhomogeneous KdV-type equation for the second-order perturbed potentials are derived. Stationary solutions of these coupled equations are obtained using a renormalization method. The effects of the external oblique magnetic field, hot ion fluid, and higher-order nonlinearity on the nature of the ion acoustic solitary waves are discussed. The results complement and provide new insights into previously published results on this problem [R. S. Tiwari and M. K. Mishra, Phys. Plasmas 13, 062112 (2006)].
Localized excitations of charged dust grains in dusty plasma lattices
Kourakis, Ioannis; Shukla, Padma Kant; Basios, Vassileios
2005-10-31
The nonlinear aspects of charged dust grain motion in a one-dimensional dusty plasma (DP) monolayer are discussed. Both horizontal (longitudinal, acoustic mode) and vertical (transverse, optic mode) displacements are considered, and various types of localized excitations are reviewed, in a continuum approximation. Dust crystals are shown to support nonlinear kink-shaped supersonic longitudinal solitary excitations, as well as modulated envelope (either longitudinal or transverse) localized modes. The possibility for Discrete Breather (DB-) type excitations (Intrinsic Localized Modes, ILMs) to occur is investigated, from first principles. These highly localized excitations owe their existence to lattice discreteness, in combination with the interaction and/or substrate (sheath) potential nonlinearity. This possibility may open new directions in DP- related research. The relation to previous results on atomic chains as well as to experimental results on strongly-coupled dust layers in gas discharge plasmas is discussed.
Propagation of electromagnetic wave in dusty plasma and the influence of dust size distribution
NASA Astrophysics Data System (ADS)
Li, Hui; Wu, Jian; Zhou, Zhongxiang; Yuan, Chengxun
2016-07-01
The effect of charged dust particle and their size distribution on the propagation of electromagnetic wave in a dusty plasma is investigated. It is shown that the additional collision mechanism provided by charged dust particles can significantly alter the electromagnetic properties of a plasma, leading to the appearance of attenuation of electromagnetic wave through dusty plasma. The attenuation coefficient mainly depends on the dust density, radius, and the charge numbers on the dust surface. The results described here will be used to enhance understanding of electromagnetic wave propagation processed in space and laboratory dusty plasma.
Synchronization pattern observed in a complex (dusty) plasma
NASA Astrophysics Data System (ADS)
Zhdanov, Sergey; Couedel, Lenaic; Morfill, Gregor
2015-04-01
Complex or dusty plasmas are weakly ionized gases containing micron-size particles called dust particles or microparticles. In a laboratory radio-frequency (rf) plasma these particles are negatively charged. Due to their strong interactions with the plasma and with each other, they can form strongly coupled systems. Complex plasmas are ideal model systems for phase transitions, self-organization and transport processes. We report on the kinematics of dust particles during the early stage of mode-coupling induced melting of a two-dimensional plasma crystal. It was found that the formation of the hybrid mode causes the particle vibrations to partially synchronize at the hybrid frequency. The system self-organizes in a rhythmic pattern of alternating in-phase and anti-phase oscillating chains of particles. Phase- and frequency-locked hybrid particle motion in both vertical and horizontal directions is evidenced. The spatial orientation of the synchronization pattern correlates well with the directions of the maximal increment of the shear-free hybrid mode. Dynamically, a two-dimensional plasma crystal can be seen as an ensemble of coupled nonlinear oscillators. Spontaneous emergence of synchronized signals and spontaneous symmetry breaking are typical behaviors in such large populations of interacting units.
Initial Results from the Magnetized Dusty Plasma Experiment (MDPX)
NASA Astrophysics Data System (ADS)
Thomas, Edward; Konopka, Uwe; Lynch, Brian; Adams, Stephen; Leblanc, Spencer; Artis, Darrick; Dubois, Ami; Merlino, Robert; Rosenberg, Marlene
2014-10-01
The MDPX device is envisioned as a flexible, multi-user, research instrument that can perform a wide range of studies in fundamental and applied plasma physics. The MDPX device consists of two main components. The first is a four-coil, open bore, superconducting magnet system that is designed to produce uniform magnetic fields of up to 4 Tesla and non-uniform magnetic fields with gradients up to up to 2 T/m configurations. Within the warm bore of the magnet is placed an octagonal vacuum chamber that has a 46 cm outer diameter and is 22 cm tall. The primary missions of the MDPX device are to: (1) investigate the structural, thermal, charging, and collective properties of a plasma as the electrons, ions, and finally charged microparticles become magnetized; (2) study the evolution of a dusty plasma containing magnetic particles (paramagnetic, super-paramagnetic, or ferromagnetic particles) in the presence of uniform and non-uniform magnetic fields; and, (3) explore the fundamental properties of strongly magnetized plasmas (``i.e., dust-free'' plasmas). This presentation will summarize the initial characterization of the magnetic field structure, initial plasma parameter measurements, and the development of in-situ and optical diagnostics. This work is supported by funding from the NSF and the DOE.
Nonlinear plasma voids (holes) in a charge-varying dusty plasma
Tribeche, Mouloud; Ait Gougam, Leila; Aoutou, Kamel; Zerguini, Taha Houssine
2005-09-15
Nonlinear large amplitude plasma voids are investigated in a charge-varying dusty plasma. Numerical solutions of highly nonlinear equations are carried out including dust charging and ion trapping. The results complement previously published results on this problem. It is found that under certain conditions the effect of dust charge variation can be quite important. In particular, it may be noted that the dust charge variation leads to an additional enlargement of the nonlinear plasma voids.
NASA Astrophysics Data System (ADS)
Fortov, Vladimir
Dusty, or complex plasmas are composed of a weakly ionized gas and charged microparticles. Dust and dusty plasmas are ubiquitous in space -- they are present in planetary rings, cometary tails, interplanetary and interstellar clouds, the mesosphere, thunderclouds, they are found in the vicinity of artificial satellites and space stations, etc. Dusty plasmas formed by micronsize particles are actively investigated in many laboratories. This research has many interesting applications like nanomaterial synthesis, nanoparticle handling or particle waste removal just to mention a few. But, the most interesting application of dusty plasmas is the use as model systems for fundamental physics. It allows investigation on the most fundamental -- the kinetic level and provides insights into physics of solids and liquids with a precision not achievable in natural systems. Experiments performed on Earth are always altered or even hindered by gravity. Microgravity conditions are necessary to make investigations of large homogeneous 3-dimensional dusty plasma systems. Here we present the survey of results of the dusty plasma physics investigations under microgravity conditions with the help of experimental installations ``Plasma Crystal-1'' (PK-1) and ``PK-2'' used on the Orbital Station ``Mir'', and the unique experimental installations ``PK-3'' and ``PK-3 Plus'' used on the International Space Station. The use of these installations has given a possibility to obtain new knowledge on the dusty plasma properties. The phase transition from the isotropic liquid dusty plasma system to the so-called electrorheological plasma has been performed. The transition is the isotropic one and is fully reversible. The other interesting phenomenon is an interpenetration of two clouds of microparticles of different sizes. When a velocity of the penetrating particles is rather high the lane formation has been observed. This phenomenon is the non-equilibrium transition, depends upon peculiarities
Nonlinear wave propagation in strongly coupled dusty plasmas.
Veeresha, B M; Tiwari, S K; Sen, A; Kaw, P K; Das, A
2010-03-01
The nonlinear propagation of low-frequency waves in a strongly coupled dusty plasma medium is studied theoretically in the framework of the phenomenological generalized hydrodynamic (GH) model. A set of simplified model nonlinear equations are derived from the original nonlinear integrodifferential form of the GH model by employing an appropriate physical ansatz. Using standard perturbation techniques characteristic evolution equations for finite small amplitude waves are then obtained in various propagation regimes. The influence of viscoelastic properties arising from dust correlation contributions on the nature of nonlinear solutions is discussed. The modulational stability of dust acoustic waves to parallel perturbation is also examined and it is shown that dust compressibility contributions influenced by the Coulomb coupling effects introduce significant modification in the threshold and range of the instability domain. PMID:20365882
Nonlinear wave propagation in strongly coupled dusty plasmas
Veeresha, B. M.; Tiwari, S. K.; Sen, A.; Kaw, P. K.; Das, A.
2010-03-15
The nonlinear propagation of low-frequency waves in a strongly coupled dusty plasma medium is studied theoretically in the framework of the phenomenological generalized hydrodynamic (GH) model. A set of simplified model nonlinear equations are derived from the original nonlinear integrodifferential form of the GH model by employing an appropriate physical ansatz. Using standard perturbation techniques characteristic evolution equations for finite small amplitude waves are then obtained in various propagation regimes. The influence of viscoelastic properties arising from dust correlation contributions on the nature of nonlinear solutions is discussed. The modulational stability of dust acoustic waves to parallel perturbation is also examined and it is shown that dust compressibility contributions influenced by the Coulomb coupling effects introduce significant modification in the threshold and range of the instability domain.
Nonlinear waves in nonplanar and nonuniform dusty plasmas
Xue Jukui; Zhang Liping
2006-02-15
The nonlinear properties of the dust acoustic solitary wave and shock wave in inhomogeneous nonplanar dusty plasmas are considered theoretically and numerically. The effects of nonthermally distributed ions, nonadiabatic dust charge fluctuation, and the inhomogeneity caused by nonuniform equilibrium particle density, nonuniform equilibrium charging, and nonplanar geometry on waves are presented. When {tau}{sub ch}/{tau}{sub d} is small but finite, where {tau}{sub ch} is the charging time scale and {tau}{sub d} is the hydrodynamical time scale, a variable coefficients nonplanar Korteweg-de Vries (KdV) Burgers equation governing the nonlinear waves is derived by the perturbation method. The analytical expressions for the evolution of soliton and shock wave (both oscillatory and monotone shock) are obtained and the theoretical results are confirmed by the numerical solution of the nonlinear wave equation.
Shearing the Cold Dusty Plasma Liquid at Discrete Level
NASA Astrophysics Data System (ADS)
Yang, Chi; Chen, Meng-Chun; I, Lin
The dynamics of the cold dusty plasma liquid sheared by a laser beam is investigated experimentally, through direct optical visualization. When the cold liquid is weakly sheared, a stick-slip type flow is found due to the presence of the crystalline ordered domain. The vortical cooperative motion of particle, identified by the analysis of bond angle variation, is found to be similar to the shear-free case. The rotation of large ordered patch through rupturing into multiple rotating patches followed by the healing process is the key mechanism of vortical motion. When the liquid is strongly sheared, the emergence of the fluidized band induced by the serious domain rupture makes the vortical motion different from the weakly sheared case.
Gas flow driven by thermal creep in dusty plasma
Flanagan, T. M.; Goree, J.
2009-10-15
Thermal creep flow (TCF) is a flow of gas driven by a temperature gradient along a solid boundary. Here, TCF is demonstrated experimentally in a dusty plasma. Stripes on a glass box are heated by laser beam absorption, leading to both TCF and a thermophoretic force. The design of the experiment allows isolating the effect of TCF. A stirring motion of the dust particle suspension is observed. By eliminating all other explanations for this motion, we conclude that TCF at the boundary couples by drag to the bulk gas, causing the bulk gas to flow, thereby stirring the suspension of dust particles. This result provides an experimental verification, for the field of fluid mechanics, that TCF in the slip-flow regime causes steady-state gas flow in a confined volume.
Electrostatic drift modes in quantum dusty plasmas with Jeans terms
Ren Haijun; Wu Zhengwei; Cao Jintao; Chu, Paul K.
2009-10-15
Electrostatic drift waves (EDWs) are investigated in nonuniform quantum magnetized dusty plasmas by taking into account dust gravitational effects with the help of the quantum hydrodynamic model. Ions and electrons are viewed as low-temperature Fermi gases, whereas quantum effects are neglected for the dust grains. The analytical dispersion relationship of the quantum EDWs is derived. Quantum effects are shown to affect the dispersion of EDW significantly. The Jeans terms induce a driftlike instability, which does not exist with the absence of gravitational effects. The criteria and growth rate of the kind of instability are presented. Our results are relevant to dense astrophysical objects such as the interiors of astrophysical compact objects (e.g., white dwarfs and neutron stars)
Hydrodynamic waves and correlation functions in dusty plasmas
Wang, X.; Bhattacharjee, A.
1997-11-01
A hydrodynamic description of strongly coupled dusty plasmas is given when physical quantities vary slowly in space and time and the system can be assumed to be in local thermodynamic equilibrium. The linear waves in such a system are analyzed. In particular, a dispersion equation is derived for low-frequency dust acoustic waves, including collisional damping effects, and compared with experimental results. The linear response of the system is calculated from the fluctuation-dissipation theorem and the hydrodynamic equations. The requirement that these two calculations coincide constrains the particle correlation function for slowly varying perturbations. It is shown that in the presence of weakly damped, long-wavelength dust-acoustic waves, the dust autocorrelation function is of the Debye{endash}H{umlt u}ckel form and the characteristic shielding distance is the dust Debye length. {copyright} {ital 1997 American Institute of Physics.}
Do nonlinear waves evolve in a universal manner in dusty and other plasma environments?
NASA Astrophysics Data System (ADS)
Bharuthram, R.; Singh, S. V.; Maharaj, S. K.; Moolla, S.; Lazarus, I. J.; Reddy, R. V.; Lakhina, G. S.; Lakhina
2014-12-01
Using a fluid theory approach, this article provides a comparative study on the evolution of nonlinear waves in dusty plasmas, as well as other plasma environments, viz electron-ion, and electron-positron plasmas. Where applicable, relevance to satellite measurements is pointed out. A range of nonlinear waves from low frequency (ion acoustic and ion cyclotron waves), high frequency (electron acoustic and electron cyclotron waves) in electron-ion plasmas, ultra-low frequency (dust acoustic and dust cyclotron waves) in dusty plasmas and in electron-positron plasmas are discussed. Depending upon the plasma parameters, saw-tooth and bipolar structures are shown to evolve.
Alfven waves in dusty plasmas with plasma particles described by anisotropic kappa distributions
Galvao, R. A.; Ziebell, L. F.; Gaelzer, R.; Juli, M. C. de
2012-12-15
We utilize a kinetic description to study the dispersion relation of Alfven waves propagating parallelly to the ambient magnetic field in a dusty plasma, taking into account the fluctuation of the charge of the dust particles, which is due to inelastic collisions with electrons and ions. We consider a plasma in which the velocity distribution functions of the plasma particles are modelled as anisotropic kappa distributions, study the dispersion relation for several combinations of the parameters {kappa}{sub Parallel-To} and {kappa}{sub Up-Tack }, and emphasize the effect of the anisotropy of the distributions on the mode coupling which occurs in a dusty plasma, between waves in the branch of circularly polarized waves and waves in the whistler branch.
2-D Magnetohydrodynamic Modeling of A Pulsed Plasma Thruster
NASA Technical Reports Server (NTRS)
Thio, Y. C. Francis; Cassibry, J. T.; Wu, S. T.; Rodgers, Stephen L. (Technical Monitor)
2002-01-01
Experiments are being performed on the NASA Marshall Space Flight Center (MSFC) MK-1 pulsed plasma thruster. Data produced from the experiments provide an opportunity to further understand the plasma dynamics in these thrusters via detailed computational modeling. The detailed and accurate understanding of the plasma dynamics in these devices holds the key towards extending their capabilities in a number of applications, including their applications as high power (greater than 1 MW) thrusters, and their use for producing high-velocity, uniform plasma jets for experimental purposes. For this study, the 2-D MHD modeling code, MACH2, is used to provide detailed interpretation of the experimental data. At the same time, a 0-D physics model of the plasma initial phase is developed to guide our 2-D modeling studies.
Complex (dusty) plasmas-kinetic studies of strong coupling phenomena
Morfill, Gregor E.; Ivlev, Alexei V.; Thomas, Hubertus M.
2012-05-15
'Dusty plasmas' can be found almost everywhere-in the interstellar medium, in star and planet formation, in the solar system in the Earth's atmosphere, and in the laboratory. In astrophysical plasmas, the dust component accounts for only about 1% of the mass, nevertheless this component has a profound influence on the thermodynamics, the chemistry, and the dynamics. Important physical processes are charging, sputtering, cooling, light absorption, and radiation pressure, connecting electromagnetic forces to gravity. Surface chemistry is another important aspect. In the laboratory, there is great interest in industrial processes (e.g., etching, vapor deposition) and-at the fundamental level-in the physics of strong coupling phenomena. Here, the dust (or microparticles) are the dominant component of the multi-species plasma. The particles can be observed in real time and space, individually resolved at all relevant length and time scales. This provides an unprecedented means for studying self-organisation processes in many-particle systems, including the onset of cooperative phenomena. Due to the comparatively large mass of the microparticles (10{sup -12}to10{sup -9}g), precision experiments are performed on the ISS. The following topics will be discussed: Phase transitions, phase separation, electrorheology, flow phenomena including the onset of turbulence at the kinetic level.
Dusty Plasmas - Kinetic Studies of Strong Coupling Phenomena
NASA Astrophysics Data System (ADS)
Morfill, Gregor
2011-10-01
``Dusty plasmas'' can be found almost everywhere - in the interstellar medium, in star and planet formation, in the solar system in the Earth's atmosphere and in the laboratory. In astrophysical plasmas the dust component accounts for only about 1% of the mass, nevertheless this component has a profound influence on the thermodynamics, the chemistry and the dynamics. Important physical processes are charging, sputtering, cooling, light absorption and radiation pressure, connecting electromagnetic forces to gravity. Surface chemistry is another important aspect. In the laboratory there is great interest in industrial processes (e.g. etching, vapor deposition) and at the fundamental physics level - the main topic here - the study of strong coupling phenomena. Here the dust (or microparticles) are the dominant component of the multi-species plasma. The particles can be observed in real time and pace, individually resolved at all relevant length and time scales. This provides an unprecedented means for studying self-organisation processes in many particle systems including the onset of cooperative phenomena. Due to the comparatively large mass of the microparticles (10-12 to 10-9 g) precision experiments are performed on the ISS. The following topics will be discussed: Phase transitions, phase separation, electrorheology, flow phenomena including the onset of turbulence at the kinetic level.
Solitons in dusty plasmas with positive dust grains
Baluku, T. K.; Hellberg, M. A.; Mace, R. L.
2008-03-15
Although ''typical'' micrometer-sized dust grains in a space or laboratory plasma are often negatively charged because of collisions with the mobile electrons, there are environments in which grains may take on a positive charge. We consider a dusty plasma composed of electrons, positive ions and positive dust grains, and use the fluid dynamic paradigm to identify existence domains in parameter space for both dust-acoustic (DA) and dust-modified ion-acoustic (DIA) solitons. Only positive potential DA solitons are found. This represents an expected antisymmetry with the case of negative dust, where previously only negative solitons were reported. However, whereas for negative dust DIA solitons of either sign of potential may exist, we find that for the case of positive dust, DIA solitons are restricted to positive potentials only. The results for both positive and negative dust are consistent with an hypothesis that, in the absence of flows, the sign(s) of the soliton potential coincide(s) with the sign(s) of the species whose inertia is included in the calculation; i.e., the cold, supersonic species present in the plasma.
Farley-Buneman instability in dusty space plasma
Atamaniuk, B.; Rothkaehl, H.; Volokitin, A.
2011-11-29
The dusty plasma and turbulent plasma properties in the vicinity of Jupiter and particularly inside the Ganymede magnetosphere can be a key parameters for understanding the plasma processes The complex system magnetic and electric field inside the Jowian magnetosphere can drive electrojet. If these currents exceed a certain critical amplitude, a streaming instability called the Farley-Buneman or a collisional two-stream instability develops. This instability grows more rapidly at shorter wavelengths and the waves propagate nearly perpendicular to the magnetic field. It is well known that even system with finite number of interacting waves can realize a turbulent state in active media. In such cases, when the number of cooperating waves remains small due to a competition of processes of their instability and attenuation, the turbulence appears in the result of their stochastic behavior. We study of nonlinear stabilization and influence of the dust component, conditions of stochasticity and the different regimes in the conditions when the number of interacting waves keeps small by the strong competition of processes wave damping and instabilities are considered.
Dusty Plasma Experimental (DPEx) device for complex plasma experiments with flow
NASA Astrophysics Data System (ADS)
Jaiswal, S.; Bandyopadhyay, P.; Sen, A.
2015-11-01
A versatile table-top dusty plasma experimental device to study flow induced excitations of linear and nonlinear waves/structures in a complex plasma is presented. In this Π-shaped apparatus, a DC glow discharge plasma is produced between a disc shaped anode and a grounded long cathode tray by applying a high voltage DC in the background of a neutral gas (argon) and subsequently a dusty plasma is created by introducing micron sized dust particles that get charged and levitated in the sheath region. A flow of the dust particles is induced in a controlled manner by adjusting the pumping speed and the gas flow rate into the device. A full characterisation of the plasma, using Langmuir and emissive probe data, and that of the dusty plasma using particle tracking data with the help of an idl based (super) Particle Identification and Tracking (sPIT) code is reported. Experimental results on the variation of the dust flow velocity as a function of the neutral pressure and the gas flow rate are given. The neutral drag force acting on the particles and the Epstein coefficient are estimated from the initial acceleration of the particles. The potential experimental capabilities of the device for conducting fundamental studies of flow induced instabilities are discussed.
Dusty Plasma Experimental (DPEx) device for complex plasma experiments with flow.
Jaiswal, S; Bandyopadhyay, P; Sen, A
2015-11-01
A versatile table-top dusty plasma experimental device to study flow induced excitations of linear and nonlinear waves/structures in a complex plasma is presented. In this Π-shaped apparatus, a DC glow discharge plasma is produced between a disc shaped anode and a grounded long cathode tray by applying a high voltage DC in the background of a neutral gas (argon) and subsequently a dusty plasma is created by introducing micron sized dust particles that get charged and levitated in the sheath region. A flow of the dust particles is induced in a controlled manner by adjusting the pumping speed and the gas flow rate into the device. A full characterisation of the plasma, using Langmuir and emissive probe data, and that of the dusty plasma using particle tracking data with the help of an idl based (super) Particle Identification and Tracking (sPIT) code is reported. Experimental results on the variation of the dust flow velocity as a function of the neutral pressure and the gas flow rate are given. The neutral drag force acting on the particles and the Epstein coefficient are estimated from the initial acceleration of the particles. The potential experimental capabilities of the device for conducting fundamental studies of flow induced instabilities are discussed. PMID:26628131
The Perspectives of Laboratory Dusty Plasmas for the Applications in Astrophysics
Kovacevic, E.; Berndt, J.; Boufendi, Laifa; Mutschke, Harald; Stefanovic, I.; Winter, J.; Pendleton, Yvonne J.
2008-09-07
It is very well known fact that dust and dusty plasmas are ubiquitous in the space: from interstellar media, to cometary dust, planetary rings and so on. The phenomena concerning the dust in space, seems to have an immense number of facets. The help for the identification of some of the phenomena, or tracing the new ones, has coming during last few decades more and more from the physics of dusty plasmas. We present an overview on the development in the application of laboratory dusty plasmas seizing from the production of interstellar analogs, investigations connected with the field of the interplanetary dust and planet-formation, charging phenomena and their future possibilities of the dusty plasma applications in this field.
A Synopsis of Recent Experimental Developments in Complex (Dusty) Plasma Physics
NASA Astrophysics Data System (ADS)
Morfill, G. E.
2002-12-01
A brief summary is presented of recent developments in laboratory studies of complex (dusty) plasmas, both in terrestrial laboratories and under microgravity conditions, together with a short discussion of possible future developments.
Phase Transitions in Quasi-2D Plasma-Dust Systems: Simulations and Experiments
NASA Astrophysics Data System (ADS)
Petrov, Oleg; Vasiliev, Mikhail; Statsenko, Konstantin; Koss, Xeniya; Vasilieva, Elena; Myasnikov, Maxim; Lisin, Evgeny
2015-11-01
A nature of phase transition in quasi-2D dusty plasma structures was studied and the influence of the quasi-2D cluster size (a number of particles in it) on the features of the phase transition was investigated. Experiments and numerical simulation was conducted for the systems consisting of small (~ 10) and large (~ 103) number of particles. To investigate the phase state of the system with 7, 18 and 100 particles observed in numerical and laboratory experiments, we used the method based on analysis of dynamic entropy. Numerical modeling of small systems was conducted by the Langevin molecular dynamic method with the Langevin force, responsible for the stochastic nature of the motion of particles with a given kinetic temperature. Phase state of systems with the number of elements in the order of 103, was studied using the methods of statistical thermodynamics. Here we present new results of an experimental study of the change of translational and orientational order and topological defects, and the pair interactions at 2D melting of dust cluster in rf discharge plasma. The experimental results have revealed the existence of hexatic phase as well as solid-to-hexatic phase and hexatic-to-liquid transitions. This work was supported by the Russian Science Foundation (O.F. Petrov, M.M.Vasiliev, K.B. Stacenko, X.G. Koss, E.V. Vasilieva, M.I.Myasnikov and E.?.Lisin) through Grant No. 14-12-01440).
Rescaling effects on a low-frequency drift wave in dusty plasmas
NASA Astrophysics Data System (ADS)
Qiu, Xin; Liu, Sanqiu
2015-03-01
The effect of dust on the low-frequency drift wave in inhomogeneous magnetized dusty plasmas is investigated. It is shown that a low-frequency drift wave can be modeled by the Hasegawa-Mima equation (HME) both in mobile and immobile dusty plasmas, which are dust-modified HME and HME in dusty background, respectively. The former is rescaled significantly by the presence of the dust and the space-time scale greatly increases with the increasing density and mass of dust, while the latter is not rescaled, but an additional driving force appears to drive the drift waves.
3D dust clouds (Yukawa Balls) in strongly coupled dusty plasmas
Melzer, A.; Passvogel, M.; Miksch, T.; Ikkurthi, V. R.; Schneider, R.; Block, D.; Piel, A.
2010-06-16
Three-dimensional finite systems of charged dust particles confined to concentric spherical shells in a dusty plasma, so-called 'Yukawa balls', have been studied with respect to their static and dynamic properties. Here, we review the charging of particles in a dusty plasma discharge by computer simulations and the respective particle arrangements. The normal mode spectrum of Yukawa balls is measured from the 3D thermal Brownian motion of the dust particles around their equilibrium positions.
Particle position and velocity measurement in dusty plasmas using particle tracking velocimetry
NASA Astrophysics Data System (ADS)
Feng, Yan; Goree, J.; Haralson, Zach; Wong, Chun-Shang; Kananovich, A.; Li, Wei
2016-06-01
> Methods of imaging and image analysis are presented for dusty plasma experiments. Micron-sized polymer spheres, electrically suspended in a partially ionized gas, are illuminated by a sheet of laser light and imaged by video cameras. Image analysis methods yield particle positions and velocities of individual particles in each video image. Methods to minimize errors in the particle positions and velocities, which are now commonly used in the dusty plasma community, are described.
Effect of radio frequency discharge power on dusty plasma parameters
Sheridan, T. E.
2009-08-01
The parameters of a two-dimensional dusty plasma consisting of six, 9 mum diameter particles trapped inside a radio frequency (rf) plasma sheath have been measured as a function of rf power in a 13.5 mtorr (1.8 Pa) argon discharge. The center-of-mass and breathing frequencies are found by projecting the cluster's Brownian motion onto the associated normal mode. The center-of-mass frequency (i.e., radial confinement) is insensitive to rf power. The Debye shielding parameter kappa, as found from the breathing frequency, increases from approx =0.5 to 2 as the square root of rf power. The Debye length decreases from approx =2.7 to 0.7 mm as the inverse of the square root of rf power. The average particle charge qapprox =-17 000e is effectively independent of rf power. These results are consistent with an electron temperature that is independent of rf power and an ion density that is directly proportional to rf power, where the Debye length is determined by the ion density in combination with the electron temperature.
Dusty Plasma Physics Facility for the International Space Station
NASA Astrophysics Data System (ADS)
Goree, John; Hahn, Inseob
2015-09-01
The Dusty Plasma Physics Facility (DPPF) is an instrument planned for the International Space Station (ISS). If approved by NASA, JPL will build and operate the facility, and NASA will issue calls for proposals allowing investigators outside JPL to carry out research, public education, and outreach. Microgravity conditions on the ISS will be useful for eliminating two unwanted effects of gravity: sedimentation of dust particles to the bottom of a plasma chamber, and masking weak forces such as the ion drag force that act on dust particles. The DPPF facility is expected to support multiple scientific users. It will have a modular design, with a scientific locker, or insert, that can be exchanged without removing the entire facility. The first insert will use a parallel-plate radio-frequency discharge, polymer microspheres, and high-speed video cameras. This first insert will be designed for fundamental physics experiments. Possible future inserts could be designed for other purposes, such as engineering applications, and experimental simulations of astrophysical or geophysical conditions. The design of the facility will allow remote operation from ground-based laboratories, using telescience.
Construction of a hybrid rf/dc discharge source for dusty plasma studies
NASA Astrophysics Data System (ADS)
Krupa, Justin; Williams, Jeremiah
2014-10-01
A complex (dusty) plasma is a four-component system composed of ions, electrons, neutral particles and charged microparticles. The presence of the microparticles gives rise to new plasma phenomena at time scales on the order of Hertz. Over the last several years, the Wittenberg University Plasma Laboratory has studied these dusty plasma systems in a dc discharge plasma. In this poster, we present work on a dual rf/dc hybrid discharge system to replace the dc glow discharge system currently in use. Details of the design and use of 3D printing in the construction will be presented. This work supported by National Science Foundation Grant Number PHY-0953595.
Cross correlation analysis of plasma perturbation in amplitude modulated reactive dusty plasmas
NASA Astrophysics Data System (ADS)
Ito, Teppei; Soejima, Masahiro; Yamashita, Daisuke; Seo, Hyunwoong; Itagaki, Naho; Koga, Kazunori; Shiratani, Masaharu; Kobayashi, Tatsuya; Inagaki, Shigeru
2015-09-01
Interactions between plasmas and nano-interface are one of the most important issues in plasma processing. We have studied effects of plasma perturbation on growth of nanoparticles in amplitude modulated reactive dusty plasmas and have clarified that amplitude modulation (AM) leads to suppression of growth of nanoparticles [1]. Here we report results of cross correlation analysis of time evolution of laser light scattering intensity from nanoparticles in reactive plasmas. Experiments were carried out using a capacitively-coupled rf discharge reactor with a two-dimensional laser light scattering (LLS) system. We employed Ar +DM-DMOS discharge plasmas to generate nanoparticles. The peaks at higher harmonics and subharmonics in spectra of laser light scattering intensity were detected, suggesting nonlinear coupling between plasma and nanoparticle amount. We found high cross correlation t between waves at AM frequency and its higher harmonics. Namely, perturbation at fAM closely correlates with those at higher harmonics.
Galvao, R. A.; Ziebell, L. F.
2012-09-15
In this work, we detail the derivation of a plasma kinetic theory leading to the components of the dielectric tensor for a magnetized dusty plasma with variable charge on the dust particles, considering that the dust component of the plasma contains spherical dust particles with different sizes, which are charged both by inelastic collisions of electrons and ions and by photoionization.
Hydrodynamic Waves and Correlation Functions in Dusty Plasmas
NASA Astrophysics Data System (ADS)
Bhattacharjee, A.; Wang, Xiaogang
1997-11-01
A hydrodynamic description of strongly coupled dusty plasmas is given when physical quantities vary slowly in space and time and the system can be assumed to be in local thermodynamic equilibrium. The linear waves in such a system are analyzed. In particular, a dispersion equation is derived for low-frequency dust acoustic waves, including collisional damping effects, and compared with experimental results. The linear response of the system is calculated from the fluctuation-dissipation theorem and the hydrodynamic equations. The requirement that these two calculations coincide constrains the particle correlation function for slowly varying perturbations [L. P. Kadanoff and P. C. Martin, Ann. Phys. 24, 419 (1963)]. It is shown that in the presence of the slow dust-acoustic waves, the dust auto-correlation function is of the Debye-Hekel form and the shielding distance is the dust Debye length. In the short-wavelength regime, an integral equation is derived from kinetic theory and solved numerically to yield particle correlation functions that display ``liquid-like'' behavior and have been observed experimentally [R. A.. Quinn, C. Cui, J. Goree, J. B. Pieper, H. Thomas and G. E. Morfill, Phys. Rev. E 53, R2049 (1996)].
Spherical crystals in dusty plasmas - Simulation and theory
NASA Astrophysics Data System (ADS)
Bonitz, M.; Henning, C.; Golubnychiy, V.; Baumgartner, H.; Ludwig, P.; Arp, O.; Block, D.; Piel, A.; Melzer, A.; Kraeft, W. D.
2006-10-01
Coulomb crystals in spherically symmetric traps have been found in trapped cold ions and, recently, in dusty plasmas at room temperature [1] allowing for precision measurements, including individual particle positions and trajectories. Thus, for the first time, strong correlation phenomena can be studied directly on the microscopic level which allows for detailed comparisons with theoretical results and computer simulations. We present molecular dynamics and Monte Carlo simulations of Coulomb crystals in the range from 10 to 10,000 particles which agree very well with the measurements [3]. The results include the ground state shell configurations and symmetry properties [2,3], the crystal stability and melting behavior. Finally, a thermodynamic theory is developed and compared to simpler models, such as shell models [4]. [1] O. Arp, D. Block, A. Piel, and A. Melzer, Phys. Rev. Lett. 93, 165004 (2004). [2] P. Ludwig, S. Kosse, and M. Bonitz, Phys. Rev. E 71, 046403 (2005). [3] M. Bonitz, D. Block, O. Arp, V. Golubnychiy, H. Baumgartner, P. Ludwig, A. Piel, and A. Filinov, Phys. Rev. Lett. 96, 075001 (2006). [4] C. Henning et al., submitted for publication.
Effect of random charge fluctuation on strongly coupled dusty Plasma
Issaad, M.; Rouiguia, L.; Djebli, M.
2008-09-07
Modeling the interaction between particles is an open issue in dusty plasma. We dealt with strongly coupled dust particles in two dimensional confined system. For small number of clusters, we investigate the effect of random charge fluctuation on background configuration. The study is conducted for a short rang as well as a long rang potential interaction. Numerical simulation is performed using Monte-Carlo simulation in the presence of parabolic confinement and at low temperature. We have studied the background configurations for a dust particles with constant charge and in the presence of random charge fluctuation due to the discrete nature of charge carriers. The latter is studied for a positively charged dust when the dominant charging process is due to photo-emission from the dust surface. It is found, for small classical cluster consisting of small number of particles, short rang potential gives the same result as long rang one. It is also found that the random charge fluctuation affect the background configurations.
Kolmogorov flow in two dimensional strongly coupled dusty plasma
Gupta, Akanksha; Ganesh, R. Joy, Ashwin
2014-07-15
Undriven, incompressible Kolmogorov flow in two dimensional doubly periodic strongly coupled dusty plasma is modelled using generalised hydrodynamics, both in linear and nonlinear regime. A complete stability diagram is obtained for low Reynolds numbers R and for a range of viscoelastic relaxation time τ{sub m} [0 < τ{sub m} < 10]. For the system size considered, using a linear stability analysis, similar to Navier Stokes fluid (τ{sub m} = 0), it is found that for Reynolds number beyond a critical R, say R{sub c}, the Kolmogorov flow becomes unstable. Importantly, it is found that R{sub c} is strongly reduced for increasing values of τ{sub m}. A critical τ{sub m}{sup c} is found above which Kolmogorov flow is unconditionally unstable and becomes independent of Reynolds number. For R < R{sub c}, the neutral stability regime found in Navier Stokes fluid (τ{sub m} = 0) is now found to be a damped regime in viscoelastic fluids, thus changing the fundamental nature of transition of Kolmogorov flow as function of Reynolds number R. A new parallelized nonlinear pseudo spectral code has been developed and is benchmarked against eigen values for Kolmogorov flow obtained from linear analysis. Nonlinear states obtained from the pseudo spectral code exhibit cyclicity and pattern formation in vorticity and viscoelastic oscillations in energy.
Current-driven dust ion-acoustic instability in a collisional dusty plasma
Merlino, R.L.
1997-02-01
A fluid analysis of the excitation of dust ion-acoustic (DIA) waves in a collisional dusty plasma is presented. The DIA waves are excited by a relative drift of the electrons and ions produced by a steady-state electric field applied to the plasma. The DIA instability is more easily excited if the relative concentration of negatively charged dust is increased. The current interest in dusty plasmas is due to the realization of their importance in various astrophysical and geophysical environments (e.g., interstellar space, comet tails, planetary ring systems, and the polar mesosphere) as well as in industrial plasma processing devices used in semiconductor manufacturing.
Observations of imposed ordered structures in a dusty plasma at high magnetic field
NASA Astrophysics Data System (ADS)
Thomas, Edward; Lynch, Brian; Konopka, Uwe; Merlino, Robert L.; Rosenberg, Marlene
2015-03-01
Dusty plasmas have been studied in argon, rf glow discharge plasmas at magnetic fields up to 2 T, where the electrons and ions are strongly magnetized. In this experiment, plasmas are generated between two parallel plate electrodes where the lower, powered electrode is solid and the upper, electrically floating electrode supports a semi-transparent, titanium mesh. We report on the formation of an ordered dusty plasma, where the dust particles form a spatial structure that is aligned to the mesh. We discuss possible mechanisms that may lead to the formation of the "dust grid" and point out potential implications and applications of these observations.
Observations of imposed ordered structures in a dusty plasma at high magnetic field
Thomas, Edward Lynch, Brian; Konopka, Uwe; Merlino, Robert L.; Rosenberg, Marlene
2015-03-15
Dusty plasmas have been studied in argon, rf glow discharge plasmas at magnetic fields up to 2 T, where the electrons and ions are strongly magnetized. In this experiment, plasmas are generated between two parallel plate electrodes where the lower, powered electrode is solid and the upper, electrically floating electrode supports a semi-transparent, titanium mesh. We report on the formation of an ordered dusty plasma, where the dust particles form a spatial structure that is aligned to the mesh. We discuss possible mechanisms that may lead to the formation of the “dust grid” and point out potential implications and applications of these observations.
Salient features of solitary waves in dusty plasma under the influence of Coriolis force
Das, G. C.; Nag, Apratim
2007-08-15
The main interest is to study the nonlinear acoustic wave in rotating dusty plasma augmented through the derivation of a modified Sagdeev potential equation. Small rotation causes the interaction of Coriolis force in the dynamical system, and leads to the complexity in the derivation of the nonlinear wave equation. As a result, the finding of solitary wave propagation in dusty plasma ought to be of merit. However, the nonlinear wave equation has been successfully solved by the use of the hyperbolic method. Main emphasis has been given to the changes on the evolution and propagation of soliton, and the variation caused by the dusty plasma constituents as well as by the Coriolis force have been highlighted. Some interesting nonlinear wave behavior has been found which can be elaborately studied for the interest of laboratory and space plasmas. Further, to support the theoretical investigations, numeric plasma parameters have been taken for finding the inherent features of solitons.
NASA Astrophysics Data System (ADS)
Matsubayashi, Yasuhito; Urabe, Keiichiro; Stauss, Sven; Terashima, Kazuo
2015-11-01
Dusty plasmas are a class of plasmas that not only have repercussions for many branches of plasma science and technology, but also thermodynamics and statistical mechanics. However, in ground-based experiments, gravity influences the dynamics and formation of plasma crystals, and the realization of zero-gravity dusty plasmas in space is very costly and time-consuming. To overcome some of these limitations, we propose dusty plasmas in supercritical fluids as a means for realizing ground-based experiments under pseudo-microgravity conditions, to study the formation and self-organization of plasma crystals. Dusty plasmas were realized by using surface dielectric barrier discharges (DBDs) generated in supercritical carbon dioxide (\\text{scC}{{\\text{O}}2} ), and the motion of fine particles above the electrode surface was studied by high-speed imaging. The plasmas deposited charge on the particles, and the particles formed a self-organized structure above the surface DBD reactor. The particle charge estimated from the analysis of particle motion was on the order of -104 to -105 e C, and the estimation of the Coulomb coupling parameter of the charged particles with a value of 102 to 104 confirmed the formation of strongly coupled plasmas.
Dust-acoustic waves and stability in the permeating dusty plasma. II. Power-law distributions
Gong Jingyu; Du Jiulin; Liu Zhipeng
2012-08-15
The dust-acoustic waves and the stability theory for the permeating dusty plasma with power-law distributions are studied by using nonextensive q-statistics. In two limiting physical cases, when the thermal velocity of the flowing dusty plasma is much larger than, and much smaller than the phase velocity of the waves, we derived the dust-acoustic wave frequency, the instability growth rate, and the instability critical flowing velocity. As compared with the formulae obtained in part I [Gong et al., Phys. Plasmas 19, 043704 (2012)], all formulae of the present cases and the resulting plasma characteristics are q-dependent, and the power-law distribution of each plasma component of the permeating dusty plasma has a different q-parameter and thus has a different nonextensive effect. Further, we make numerical analyses of an example that a cometary plasma tail is passing through the interplanetary space dusty plasma and we show that these power-law distributions have significant effects on the plasma characteristics of this kind of plasma environment.
Characteristics of the surface plasma wave in a self-gravitating magnetized dusty plasma slab
Lee, Myoung-Jae; Jung, Young-Dae
2015-11-15
The dispersion properties of surface dust ion-acoustic waves in a self-gravitating magnetized dusty plasma slab are investigated. The dispersion relation is derived by using the low-frequency magnetized dusty dielectric function and the surface wave dispersion integral for the slab geometry. We find that the self-gravitating effect suppresses the frequency of surface dust ion-acoustic wave for the symmetric mode in the long wavelength regime, whereas it hardly changes the frequency for the anti-symmetric mode. As the slab thickness and the wave number increase, the surface wave frequency slowly decreases for the symmetric mode but increases significantly for the anti-symmetric mode. The influence of external magnetic field is also investigated in the case of symmetric mode. We find that the strength of the magnetic field enhances the frequency of the symmetric-mode of the surface plasma wave. The increase of magnetic field reduces the self-gravitational effect and thus the self-gravitating collapse may be suppressed and the stability of dusty objects in space is enhanced.
Influence of the nonlinear dynamic plasma screening on the electron-dust collision in dusty plasmas
Ki, Dae-Han; Jung, Young-Dae
2012-05-07
The nonlinear dynamic plasma screening effects on the elastic electron-dust grain collision are investigated in dusty plasmas. The results show that the nonlinear dynamic screening effect significantly increases the magnitude of the eikonal phase shift. It is also found that the magnitude of the phase shift decreases with an increase of the thermal energy. In addition, it is found that the differential eikonal cross section shows the oscillatory behavior, and the oscillating peaks approach to the collision center with increasing thermal energy. It is also found that the total eikonal cross section decreases with an increase of the thermal energy.
Tribeche, Mouloud
2005-07-15
A theoretical model is presented to show the existence, formation, and possible realization of large-amplitude solitary potentials in a charge varying dusty plasma with trapped dust particles. These nonlinear localized structures are self-consistent solutions of the Vlasov equation in which the dust response is non-Maxwellian due to the dust trapping in the large-amplitude plasma potentials. The soliton suffers the well-known anomalous damping, the importance of which is roughly proportional to the dust grain velocity. Our investigation may be taken as a prerequisite for the understanding of the electrostatic solitary waves that may occur in space dusty plasmas.
Correlation between nanoparticle and plasma parameters with particle growth in dusty plasmas
Chai, Kil Byoung; Seon, C. R.; Choe, Wonho; Chung, C. W.; Yoon, N. S.
2011-01-01
Since plasma parameters are altered by dust particles, studying how plasma parameters are related to dust particle growth is an important research issue in dusty plasma. In this paper, the correlation between plasma parameters (electron temperature and ion flux) and particle parameters (particle radius and density) is investigated in silane plasma both experimentally using a floating probe and theoretically by solving balance equations including an additional electron and ion loss to the dust. The results reveal that while the ion flux shows two peak values in the early discharge phase and at the end of coagulation phase, the electron temperature shows a sudden increase in the coagulation step and a gradual decrease in the molecular accretion step. Moreover, the calculated results with the secondary electron emission taken into account produce the best fit with the experimental results. Thus the study confirms that the secondary electron emission plays a crucial role in the coagulation of the dust particles.
On the Anderson localization conjecture in Dusty Plasma
NASA Astrophysics Data System (ADS)
Liaw, Constanze; Busse, Kyle; Matthews, Lorin; Hyde, Truell
2015-11-01
In 1958, Anderson suggested that sufficiently large impurities in a semi-conductor could lead to spatial localization of electrons. This idea unfolded into the field of Anderson Localization, one of the most fascinating phenomena in solid-state physics as it plays a major role in the conductive properties of imperfectly ordered materials. The Anderson Localization Conjecture claims that random disorder of any strength causes localization of electrons in the medium. The problem has proven to be highly non-trivial. Over the years the community has argued whether spatial localization occurs in 2D for small impurities. From a mathematical standpoint, the conjecture is still considered an open question. In 2013, Liaw challenged the commonly held assumption that localization holds in 2D by introducing a new mathematically more rigorous method to test for extended states, and applying it to the discrete random Schrödinger operator. One of the advantages of the underlying method is its versatility. It can be applied to any ordered system such as colloids, crystals, and atomic lattices. In a cross-disciplinary effort we merge this method with a numerical code used to simulate 2D physics systems, in preparation for experimentally testing the theory against complex plasma crystals.
Properties of ion-particle interaction and the ion drag force in complex (dusty) plasmas
Khrapak, Sergey A.
2009-11-10
In this paper a concise overview of recent results concerning the properties of ion-particle interaction and the ion drag force in complex (dusty) plasmas is presented. Two main theoretical approaches to calculate the ion drag force--binary collision and linear plasma response formalisms are discussed. When possible, theoretical results are compared with the results from experiments and numerical simulations.
Electrostatic solitary structures in a dusty plasma with dust of opposite polarity.
Mamun, A A
2008-02-01
A four-component dusty plasma consisting of electrons, ions, positively charged warm adiabatic dust, and negatively charged cold dust is considered. The basic features of the electrostatic solitary structures in such a four-component dusty plasma are investigated by the reductive perturbation method, which is valid for the small amplitude solitary waves, and by the pseudopotential approach which is valid for the arbitrary amplitude solitary waves. It is found that the presence of the positive dust component does not only significantly modify the basic properties of the solitary potential structures, but also causes the coexistence of the positive and negative solitary potential structures, which is an interesting feature shown in a dusty plasma with the dust of opposite polarity. The basic features and the underlying physics of the electrostatic solitary structures, which are relevant to cometary tails, upper mesosphere, Jupiter's magnetosphere, etc., are briefly discussed. PMID:18352132
Dusty plasma sheath-like structure in the region of lunar terminator
NASA Astrophysics Data System (ADS)
Popel, S. I.; Zelenyi, L. M.; Atamaniuk, B.
2015-12-01
The main properties of the dusty plasma layer near the surface over the illuminated and dark parts of the Moon are described. They are used to realize dusty plasma behaviour and to determine electric fields over the terminator region. Possibility of the existence of a dusty plasma sheath-like structure in the region of lunar terminator is shown. The electric fields excited in the terminator region are demonstrated to be on the order of 300 V/m. These electric fields can result in rise of dust particles of the size of 2-3 μm up to an altitude of about 30 cm over the lunar surface that explains the effect of "horizon glow" observed at the terminator by Surveyor lunar lander.
Dusty plasma sheath-like structure in the region of lunar terminator
Popel, S. I.; Zelenyi, L. M.; Atamaniuk, B.
2015-12-15
The main properties of the dusty plasma layer near the surface over the illuminated and dark parts of the Moon are described. They are used to realize dusty plasma behaviour and to determine electric fields over the terminator region. Possibility of the existence of a dusty plasma sheath-like structure in the region of lunar terminator is shown. The electric fields excited in the terminator region are demonstrated to be on the order of 300 V/m. These electric fields can result in rise of dust particles of the size of 2–3 μm up to an altitude of about 30 cm over the lunar surface that explains the effect of “horizon glow” observed at the terminator by Surveyor lunar lander.
Beam-Plasma Instabilities in a 2D Yukawa Lattice
Kyrkos, S.; Kalman, G. J.; Rosenberg, M.
2009-06-05
We consider a 2D Yukawa lattice of grains, with a beam of other charged grains moving in the lattice plane. In contrast to Vlasov plasmas, where the electrostatic instability excited by the beam is only longitudinal, here both longitudinal and transverse instabilities of the lattice phonons can develop. We determine and compare the transverse and longitudinal growth rates. The growth rate spectrum in wave number space exhibits remarkable gaps where no instability can develop. Depending on the system parameters, the transverse instability can be selectively excited.
Ghosh, Samiran; Sarkar, Subrata; Khan, Manoranjan; Gupta, M R
2011-12-01
The effects of dust charge variations on low-frequency wave modulations in an electronegative dusty plasma are investigated. The dynamics of the modulated wave is governed by a nonlinear Schrödinger equation with a dissipative term. The dissipation arises due to the nonsteady (nonadiabatic) dust charge variations. Theoretical and numerical investigations predict the formation of dissipative bright (envelope) and dark solitons. The nonsteady charge-variation-induced dissipation reduces the modulational instability growth rate and introduces a characteristic time scale to observe bright solitons. Results are discussed in the context of electronegative dusty plasma experiments. PMID:22304202
Viscosity calculated in simulations of strongly coupled dusty plasmas with gas friction
Feng Yan; Goree, J.; Liu Bin
2011-05-15
A two-dimensional strongly coupled dusty plasma is modeled using Langevin and frictionless molecular dynamical simulations. The static viscosity {eta} and the wave-number-dependent viscosity {eta}(k) are calculated from the microscopic shear in the random motion of particles. A recently developed method of calculating the wave-number-dependent viscosity {eta}(k) is validated by comparing the results of {eta}(k) from the two simulations. It is also verified that the Green-Kubo relation can still yield an accurate measure of the static viscosity {eta} in the presence of a modest level of friction as in dusty plasma experiments.
Transverse Instability of Dust-Acoustic Solitary Waves in Magnetized Dusty Plasmas
NASA Astrophysics Data System (ADS)
Liu, Congbo; Wang, Linxue; Yang, Xue; Shi, Yuren
2015-04-01
We theoretically investigated the transverse instability of three-dimensional (3D) dust-acoustic solitary waves in a magnetized dusty plasma. First, a 3D nonlinear Zakharov-Kuznetsov (ZK) equation, which can be used to describe the time-evolution of dust-acoustic solitary waves in magnetized dusty plasmas, is derived by using the reductive perturbation method. Second, we established a numerical scheme to study the transverse instability of the solitary waves described by the ZK equation. It was found that both stable and unstable solitary waves exist. supported by National Natural Science Foundation of China (No. 11047010)
Shukla, Padma Kant; Kourakis, Ioannis; Stenflo, Lennart
2005-10-31
A generalized linear theory for electromagnetic waves in a homogeneous dusty magnetoplasma is presented. The waves described are characterized by a frequency which is much smaller (larger) than the electron gyrofrequency (dust plasma and dust gyrofrequencies), and a long wavelength (in comparison with the ion gyroradius and the electron skin depth). The generalized Hall-magnetohydrodynamic (GH-MHD) equations are derived by assuming massive charged dust macroparticles to be immobile, and Fourier transformed to obtain a general dispersion relation. The latter is analyzed to understand the influence of immobile charged dust grains on various electromagnetic wave modes in a magnetized dusty plasma.
Arbitrary Amplitude DIA and DA Solitary Waves in Adiabatic Dusty Plasmas
Mamun, A. A.; Jahan, N.; Shukla, P. K.
2008-10-15
The dust-ion-acoustic (DIA) as well as the dust-acoustic (DA) solitary waves (SWs) in an adiabatic dusty plasma are investigated by the pseudo-potential approach which is valid for arbitrary amplitude SWs. The role of the adiabaticity of electrons and ions in modifying the basic features (polarity, speed, amplitude and width) of arbitrary amplitude DIA and DA SWs are explicitly examined. It is found that the effects of the adiabaticity of electrons and ions significantly modify the basic features (polarity, speed, amplitude and width) of the DIA and DA SWs. The implications of our results in space and laboratory dusty plasmas are briefly discussed.
Design and Fabrication of a Magnetic System to Investigate Magnetized Dusty Plasmas
NASA Astrophysics Data System (ADS)
Bates, Evan M.; Romero-Talamas, Carlos A.
2013-10-01
The interest in researching the dynamics and equilibrium of magnetized dusty plasma crystallization has led to the design and fabrication of a novel experimental setup at UMBC. The proposed magnets will be an important subsystem of this setup, and will produce a uniform magnetic field of several tesla for a duration of several seconds. The magnets will be arranged in the Helmholtz configuration and will have a cooling system for temperature compensation of the coils, as well as the ability to adjust the orientation of the magnetic field with respect to gravity. Planned experiments include propagation of magnetized waves in dusty plasma crystals under various boundary conditions.
Electrostatic shock structures in a multi-species nonthermal dusty plasma
NASA Astrophysics Data System (ADS)
Tanisha, N. Y.; Tasnim, I.; Sultana, S.; Salahuddin, M.; Mamun, A. A.
2014-09-01
Propagation of the dust-acoustic shock waves (DASWs) in a dusty plasma containing arbitrarily charged dust, positive and negative ions following nonthermal (Cairn's) distribution, and electrons following q-(nonextensive) distribution, has been investigated. The reductive perturbation technique is used to derive the Burgers equation for dust's fluid dynamics. The basic features (viz. polarity, amplitude, speed, etc.) of DASWs are found to be significantly modified due to the effects of arbitrarily charged dust, number density and temperatures of heavier/lighter ions, nonextensive electrons, and dust kinematic viscosity. The present investigation can be very effective for understanding the nonlinear characteristics of the DASWs in space and laboratory dusty plasmas.
Dynamics and interactions of pulsed laser generated plasma bubbles in dusty plasma liquids
Chu Hongyu; Liao Chenting; I Lin
2005-10-31
The plasma bubble with dust particle depletion can be generated by a nano-second laser pulse focused on one of the dust particles suspended in a strongly coupled dusty plasma liquid. The bubble dynamics at different time scales, including the initial forming and later traveling stages are investigated. In the first stage, dust particles are pushed outward by the outward ion flow associated with the plume generated by the more intensed plasma. The bubble then travels downward at a speed about 60 mm/s associated with a surrounding dipole-like dust flow field. Two bubbles can also be simultaneously generated at different locations by separated laser pulses to study their interactions. Strong coupling is observed between two vertical bubbles. However, two horizontal bubbles are weakly coupled. The possible mechanism is discussed.
Polygon construction to investigate melting in two-dimensional strongly coupled dusty plasma
Ruhunusiri, W. D. Suranga; Goree, J.; Feng Yan; Liu Bin
2011-06-15
The polygon construction method of Glaser and Clark is used to characterize melting and crystallization in a two-dimensional (2D) strongly coupled dusty plasma. Using particle positions measured by video microscopy, bonds are identified by triangulation, and unusually long bonds are deleted. The resulting polygons have three or more sides. Geometrical defects, which are polygons with more than three sides, are found to proliferate during melting. Pentagons are found in liquids, where they tend to cluster with other pentagons. Quadrilaterals are a less severe defect, so that disorder can be characterized by the ratio of quadrilaterals to pentagons. This ratio is found to be less in a liquid than in a solid or a superheated solid. Another measure of disorder is the abundance of different kinds of vertices, according to the type of polygons that adjoin there. Unexpectedly, spikes are observed in the abundance of certain vertex types during rapid temperature changes. Hysteresis, revealed by a plot of a disorder parameter vs temperature, is examined to study sudden heating. The hysteresis diagram also reveals features suggesting a possibility of latent heat in the melting and rapid cooling processes.
Dusty plasmas: synthesis, structure and dynamics of a dust cloud in a plasma
NASA Astrophysics Data System (ADS)
Mikikian, M.; Couëdel, L.; Cavarroc, M.; Tessier, Y.; Boufendi, L.
2010-01-01
Plasmas are energetic media that can give birth to dust particles due to the presence of reactive gases or plasma-surface interactions. Industrial plasmas are often concerned by these dust particles that can be either unwanted or useful for the process. For fusion plasmas, production of dust particles from wall erosion is a serious issue for performance and safety reasons. In this article, some aspects of dusty plasmas with potential implications for plasma experimenters will be discussed. Convenient ways for detecting the presence or the growth of dust particles will be presented. The spatial distribution of the dust cloud during the plasma phase determines the subsequent dust particle deposition. It will be shown that some reactor regions can attract or repeal these dust particles. Finally, the dust particle dynamics after the plasma extinction will be investigated. A special attention will be paid on the residual electric charge that can stay attached on the dust particle surface and on its implications for dust particle control or deposition.
Fractal dynamics of light scattering intensity fluctuation in disordered dusty plasmas
Safaai, S. S.; Muniandy, S. V.; Chew, W. X.; Asgari, H.; Yap, S. L.; Wong, C. S.
2013-10-15
Dynamic light scattering (DLS) technique is a simple and yet powerful technique for characterizing particle properties and dynamics in complex liquids and gases, including dusty plasmas. Intensity fluctuation in DLS experiments often studied using correlation analysis with assumption that the fluctuation is statistically stationary. In this study, the temporal variation of the nonstationary intensity fluctuation is analyzed directly to show the existence of fractal characteristics by employing wavelet scalogram approach. Wavelet based scale decomposition approach is used to separate non-scaling background noise (without dust) from scaling intensity fluctuation from dusty plasma. The Hurst exponents for light intensity fluctuation in dusty plasma at different neutral gas pressures are determined. At low pressures, weaker damping of dust motions via collisions with neutral gases results in stronger persistent behavior in the fluctuation of DLS time series. The fractal scaling Hurst exponent is demonstrated to be useful for characterizing structural phases in complex disordered dusty plasma, especially when particle configuration or sizes are highly inhomogeneous which makes the standard pair-correlation function difficult to interpret. The results from fractal analysis are compared with alternative interpretation of disorder based on approximate entropy and particle transport using mean square displacement.
Interpretive 2-D treatment of scrape-off-layer plasmas
Umansky, M.; Allen, A.; Daughton, W.
1996-12-31
The width of the scrape-off-layer in a tokamak is determined by cross field transport. In Alcator C-mod the plasma parameters in the scrape-off-layer are measured at upstream and divertor plate locations. We solve a 2-D scrape-off-layer heat conduction equation in the flux geometry (as determined by EFIT) of the C-mod experiment. Bolometric measurements are utilized for the radiative loss term. We use the end wall probe measurements of electron temperature as a boundary condition and the fast scanning probe measurements of upstream temperature are treated as constraints to determine the cross field transport and thermal conductivity. Results are compared with 1-D onion-skin-model predictions.
Dust-acoustic solitary waves in a four-component adiabatic magnetized dusty plasma
Akhter, T. Mannan, A.; Mamun, A. A.
2013-07-15
Theoretical investigation has been made on obliquely propagating dust-acoustic (DA) solitary waves (SWs) in a magnetized dusty plasma which consists of non-inertial adiabatic electron and ion fluids, and inertial negatively as well as positively charged adiabatic dust fluids. The reductive perturbation method has been employed to derive the Korteweg-de Vries equation which admits a solitary wave solution for small but finite amplitude limit. It has been shown that the basic features (speed, height, thickness, etc.) of such DA solitary structures are significantly modified by adiabaticity of plasma fluids, opposite polarity dust components, and the obliqueness of external magnetic field. The SWs have been changed from compressive to rarefactive depending on the value of {mu} (a parameter determining the number of positive dust present in this plasma model). The present investigation can be of relevance to the electrostatic solitary structures observed in various dusty plasma environments (viz. cometary tails, upper mesosphere, Jupiter's magnetosphere, etc.)
Collective modes in strongly correlated yukawa liquids: waves in dusty plasmas.
Kalman, G; Rosenberg, M; DeWitt, H E
2000-06-26
We determine the collective mode structure of a strongly correlated Yukawa fluid, with the purpose of analyzing wave propagation in a strongly coupled dusty plasma. We identify a longitudinal plasmon and a transverse shear mode. The dispersion is characterized by a low- k acoustic behavior, a frequency maximum well below the plasma frequency, and a high- k merging of the two modes around the Einstein frequency of localized oscillations. The damping effect of collisions between neutrals and dust grains is estimated. PMID:10991116
Dust-gas Interactions in Dusty X-ray Emitting Plasmas
NASA Technical Reports Server (NTRS)
Dwek, Eli
2006-01-01
Dusty shocked plasmas cool primarily by infrared emission from dust that is collisionally heated by the ambient hot gas. The infrared emission provides therefore an excellent diagnostic of the conditions (density and temperature) of the shocked gas. In this review I will discuss the physical processes in these plasmas, with a particular emphasis on recent infrared observations of the interaction between the blast wave of SN1987a and its equatorial ring.
The effect of elementary reactions on solitary waves in dusty plasmas
Tahraoui, A.; Annou, R.
2012-01-15
The conditions of existence of solitons have been determined by Wang et al.[Phys. Lett. A 339, 96 (2005)], in negative ions containing dusty plasmas where Boltzmannian ions and electrons are assumed. The study is revisited taking into account actual elementary reactions in plasma conditions, viz., particles attachment by grains as well as neutrals and electron impact ionization of neutrals. Dust charge variation is self-consistently introduced leading to the Boltzmannian approximation relaxation.
Salimullah, M.; Shah, H. A.; Murtaza, G.
2007-11-15
Dust charge fluctuation instability in a dusty plasma in the presence of equilibrium density and external/ambient static magnetic field inhomogeneities has been examined in detail. The plasma ions acquire a uniform drift speed due to the equilibrium magnetic field gradient. For strongly magnetized electrons and ions, the dust charge fluctuation effect is contributed dominantly by ion dynamics. This results in an instability when the ion drift speed exceeds the perpendicular phase velocity of the waves under consideration.
2D modeling of electromagnetic waves in cold plasmas
Crombé, K.; Van Eester, D.; Koch, R.; Kyrytsya, V.
2014-02-12
The consequences of sheath (rectified) electric fields, resulting from the different mobility of electrons and ions as a response to radio frequency (RF) fields, are a concern for RF antenna design as it can cause damage to antenna parts, limiters and other in-vessel components. As a first step to a more complete description, the usual cold plasma dielectric description has been adopted, and the density profile was assumed to be known as input. Ultimately, the relevant equations describing the wave-particle interaction both on the fast and slow timescale will need to be tackled but prior to doing so was felt as a necessity to get a feeling of the wave dynamics involved. Maxwell's equations are solved for a cold plasma in a 2D antenna box with strongly varying density profiles crossing also lower hybrid and ion-ion hybrid resonance layers. Numerical modelling quickly becomes demanding on computer power, since a fine grid spacing is required to capture the small wavelengths effects of strongly evanescent modes.
Dust as In-Situ Probes for Plasma Magnetic Field Interactions in a Dusty Plasma
NASA Astrophysics Data System (ADS)
Dropmann, Michael; Laufer, Rene; Herdrich, Georg; Matthews, Lorin; Hyde, Truell
2014-10-01
A series of experiments were conducted inside a GEC rf reference cell to map the forces in three dimensions above a magnet placed in a dusty plasma and employing both horizontal and vertical orientations. Micron sized dust particles were used as in-situ probes to investigate the interaction between the low-temperature plasma produced and a magnetic field close to a non-conductive surface. Dust particles were dropped into the plasma where they obtained a negative charge leading to trajectories, which were strongly influenced by both electric and ion drag forces. By recording the trajectories of the particles, which were illuminated by a vertical laser plane, the forces onto the particles were determined. A strong influence of the magnetic field onto the plasma sheath was observed. Given the electrons are strongly magnetized by the magnet while ions remain comparatively unaffected by the magnet a charge separation takes place, which leads to strong electric fields. As a result the sheath thickness varies significantly within the magnetic field, showing strong horizontal force components. Based on these observations, analogies to the interaction of the lunar plasma with known lunar magnetic anomalies will be drawn to contribute to the explanation of the formation of lunar swirls.
Vertical Q-machine configuration for investigating ion-streaming effects in dusty plasmas
NASA Astrophysics Data System (ADS)
Koepke, M. E.; Sato, N.
2003-10-01
We have designed an experiment to electrostatically confine quiescent plasma in the Vertical Q Machine (VQ) to study the phase transition between dust-crystal and dust-fluid equilibria. The vertical orientation is for indefinitely confining a dusty-plasma layer since it permits the convenient and independent adjustment of the background neutral pressure and the magnitude, direction, and inhomogeneity of ion-relative-to-dust streaming. We will investigate the competition between neutral-particle cooling and streaming-ion energization in dusty-plasma crystallization and decrystallization over a wide range of neutral-particle pressure. Because VQ plasma production is insensitive to collisions, neutral pressure can be varied by 10000 without significantly affecting the VQ plasma properties, making the device well suited for investigating the separate roles of viscous drag and streaming instabilities in dusty-plasma, processes that compete before, during, and after the phase transition in establishing the dust kinetic temperature. The sheath-accelerated (directed), ExB (directed), and thermal (random) streaming of ions will be monitored using laser-induced fluorescence. Dust kinetic energy will be monitored by video imaging of grain-scattered laser light. We will control ion streaming using dc electric fields that are produced with biased electrodes.
Initial application of tomographic particle image velocimetry to complex (dusty) plasmas
NASA Astrophysics Data System (ADS)
Williams, J.
2010-11-01
Over the last decade, two-dimensional and stereoscopic particle image velocimetry (PIV) techniques have been applied in the study of wave, transport and thermal properties of complex (dusty) plasma. While a great deal of insight has been gained from these studies, these studies have also indicated that volumetric three-dimensional information is needed. To address this need, the Wittenberg University Plasma Laboratory (WUPL) has recently acquired and installed a tomographic PIV (tomo-PIV) diagnostic system for dusty plasma investigations. It employs a synchronized dual YAG laser, four camera system for measuring the particle transport in three dimensions over an extended volume. This poster will present information on this diagnostic technique and preliminary results.
Linear and nonlinear dynamics of current-driven waves in dusty plasmas
Ahmad, Ali; Ali Shan, S.; Haque, Q.; Saleem, H.
2012-09-15
The linear and nonlinear dynamics of a recently proposed plasma mode of dusty plasma is studied using kappa distribution for electrons. This electrostatic wave can propagate in the plasma due to the sheared flow of electrons and ions parallel to the external magnetic field in the presence of stationary dust. The coupling of this wave with the usual drift wave and ion acoustic wave is investigated. D'Angelo's mode is also modified in the presence of superthermal electrons. In the nonlinear regime, the wave can give rise to dipolar vortex structures if the shear in flow is weaker and tripolar vortices if the flow has steeper gradient. The results have been applied to Saturn's magnetosphere corresponding to negatively charged dust grains. But the theoretical model is applicable for positively charged dust as well. This work will be useful for future observations and studies of dusty environments of planets and comets.
Dust-acoustic shock waves in a magnetized non-thermal dusty plasma
NASA Astrophysics Data System (ADS)
Shahmansouri, M.; Mamun, A. A.; Mamun
2014-08-01
A theoretical investigation is carried out to study the basic properties of dust-acoustic (DA) shock waves propagating in a magnetized non-thermal dusty plasma (containing cold viscous dust fluid, non-thermal ions, and non-thermal electrons). The reductive perturbation method is used to derive the Korteweg-de Vries-Burgers equation. It is found that the basic properties of DA shock waves are significantly modified by the combined effects of dust fluid viscosity, external magnetic field, and obliqueness (angle between external magnetic field and DA wave propagation direction). It is shown that the dust fluid viscosity acts as a source of dissipation, and is responsible for the formation of DA shock structures in the dusty plasma system under consideration. The implications of our results in some space and laboratory plasma situations are briefly discussed.
Effect of nonthermality fraction on dust acoustic growth rate in inhomogeneous viscous dusty plasmas
NASA Astrophysics Data System (ADS)
El-Shewy, E. K.; El-Wakil, S. A.; El-Hanbaly, A. M.; Sallah, M.; Darweesh, H. F.
2015-04-01
The properties of linear dust acoustic (DA) waves in inhomogeneous viscous dusty plasmas with non-thermal electrons and ions have been investigated. A linear dispersion relation is obtained with the non-adiabatic dust charge fluctuation and fraction of nonthermality of electron-ion. The dependence of frequency and the damping rate of waves on the nonthermality fraction and dust kinematic viscosity coefficient are discussed. To study the dust acoustic shock waves, KdV-Burgers (KdV-B) equation for homogeneous dissipative dusty plasma has been considered and solved by means of tanh method. The obtained solution is a particular combination of a solitary wave with a Burgers shock wave. The present results are useful in the context of space plasma.
NASA Astrophysics Data System (ADS)
Melzer, André; Schella, André
2014-04-01
The method of symbolic transfer entropy has been applied to analyze the behavior of charged-particle systems under the influence of an ion focus (wakefield) in a dusty plasma. Using long-run experiments under various plasma and trapping conditions, it is revealed from the transfer entropy that information is transported from the upper particle in an ion flow to the lower. The information transfer increases with smaller interparticle distance and with reduced height in the sheath. This can be consistently explained by the formation of the ion focus by an ion flow in the sheath. From the analysis of two-particle and many-particle systems, the symbolic entropy transfer can be judged as a reliable measure for information asymmetry, and hence interaction asymmetry, in dusty plasma systems.
Melzer, André; Schella, André
2014-04-01
The method of symbolic transfer entropy has been applied to analyze the behavior of charged-particle systems under the influence of an ion focus (wakefield) in a dusty plasma. Using long-run experiments under various plasma and trapping conditions, it is revealed from the transfer entropy that information is transported from the upper particle in an ion flow to the lower. The information transfer increases with smaller interparticle distance and with reduced height in the sheath. This can be consistently explained by the formation of the ion focus by an ion flow in the sheath. From the analysis of two-particle and many-particle systems, the symbolic entropy transfer can be judged as a reliable measure for information asymmetry, and hence interaction asymmetry, in dusty plasma systems. PMID:24827184
General features and master equations for structurization in complex dusty plasmas
Tsytovich, V. N.; Morfill, G. E.
2012-02-15
Dust structurization is considered to be typical for complex plasmas. Homogeneous dusty plasmas are shown to be universally unstable. The dusty plasma structurization instability is similar to the gravitational instability and can results in creation of different compact dust structures. A general approach for investigation of the nonlinear stage of structurization in dusty plasmas is proposed and master equations for the description of self-organized structures are formulated in the general form that can be used for any nonlinear model of dust screening. New effects due to the scattering of ions on the nonlinearly screened grains are calculated: nonlinear ion dust drag force and nonlinear ion diffusion. The physics of confinement of dust and plasma components in the equilibria of compact dust structures is presented and is supported by numerical calculations of master equations. The necessary conditions for the existence of equilibrium structures are found for an arbitrary nonlinearity in dust screening. Features of compact dust structures observed in recent experiments agree with the numerically calculated ones. Some proposals for future experiments in spherical chamber are given.
The quantum dusty magnetosonic solitary wave in magnetized plasma
Wang Yunliang; Qiu Hong; Wang Fengping; Lu Yanzhen; Zhou Zhongxiang
2012-01-15
The effects of quantum statistic and quantum diffraction on the weakly two-dimensional fast quantum dusty magnetosonic wave propagating perpendicular to the external magnetic field are investigated by considering the inertialess electron, inertialess ion, and inertial cold dust in the low frequency limit. A Kadomstev-Petviashvili equation is derived for the magnetosonic solitary wave by using reductive perturbation method. The results show that the amplitude of soliton increases with the increasing of quantum diffraction effects of both electrons and ions, while the amplitude of the soliton decreases with the increasing of the quantum statistic effects. By using the numerical investigations, the interaction law of the nontrivial line-solitons with rich web structure in the interaction area among the line-solitons is studied by the Wronskian determinant method, which shows that there is no exchange of the energy, the momentum, and the angular momentum in the interaction.
NASA Astrophysics Data System (ADS)
El-Bedwehy, N. A.
2016-07-01
The reductive perturbation technique is used for investigating an ion beam-dusty plasma system consisting of two opposite polarity dusty grains, and superthermal electrons and ions in addition to ion beam. A two-dimensional Kadomtsev-Petviashvili equation is derived. The solution of this equation, employing Painlevé analysis, leads to cnoidal waves. The dependence of the structural features of these waves on the physical plasma parameters is investigated.
Dusty plasma sheath-like structure in the lunar terminator region
NASA Astrophysics Data System (ADS)
Popel, Sergey; Zelenyi, Lev; Atamaniuk, Barbara
2016-07-01
The main properties of the dusty plasma layer near the surface over the illuminated and dark parts of the Moon are described. They are used to realize dusty plasma behaviour and to determine electric fields over the terminator region. Possibility of the existence of a dusty plasma sheath-like structure [1] in the region of lunar terminator is shown. The electric fields excited in the terminator region are demonstrated to be on the order of 300 V/m. These electric fields can result in rise of dust particles of the size of a few micrometers up to an altitude of about 30 cm over the lunar surface that explains the effect of ``horizon glow" observed at the terminator by Surveyor lunar lander. This work was supported in part by the Presidium of the Russian Academy of Sciences (under Fundamental Research Program No. 7, ``Experimental and Theoretical Study of the Solar System Objects and Stellar Planet Systems. Transient Explosion Processes in Astrophysics" and the Russian Foundation for Basic Research (Project No. 15-02-05627-a). [1] S. I. Popel, L. M. Zelenyi, and B. Atamaniuk, Phys. Plasmas 22, 123701 (2015); doi: 10.1063/1.4937368.
Dust-ion acoustic cnoidal waves and associated nonlinear ion flux in a nonthermal dusty plasma
NASA Astrophysics Data System (ADS)
Ur-Rehman, Hafeez; Mahmood, S.
2016-09-01
The dust-ion acoustic nonlinear periodic (cnoidal) waves and solitons are investigated in a dusty plasma containing dynamic cold ions, superthermal kappa distributed electrons and static charged dust particles. The massive dust particles can have positive or negative charge depending on the plasma environment. Using reductive perturbation method (RPM) with appropriate periodic boundary conditions, the evolution equations for the first and second order nonlinear potentials are derived. The first order potential is determined through Korteweg-de Vries (KdV) equation which gives dust-ion acoustic cnoidal waves and solitons structures. The solution of second order nonlinear potential is obtained through an inhomogeneous differential equation derived from collecting higher order terms of dynamic equations, which is linear for second order electrostatic potential. The nonlinear ion flux associated with the cnoidal waves is also found out numerically. The numerical plots of the dust-ion acoustic cnoidal wave and soliton structures for both positively and negatively charged dust particles cases and nonthermal electrons are also presented for illustration. It is found that only compressive nonlinear electrostatic structures are formed in case of positively dust charged particles while both compressive and rarefactive nonlinear structures are obtained in case of negatively charged particles depending on the negatively charged dust density in a nonthermal dusty plasma. The numerical results are obtained using data of the ionospheric region containing dusty plasma exist in the literature.
From Dusty Plasmas in Space to Complex Plasmas under Microgravity Conditions
NASA Astrophysics Data System (ADS)
Morfill, Gregor
"Dusty Plasmas" can be found almost everywhere - in the interstellar medium, in star and planet formation, in the solar system in the Earth's atmosphere and in the laboratory. In astrophysical plasmas the dust component accounts for only about 1 percent of the mass, nevertheless this component has a profound influence on the thermodynamics, the chemistry and the dynamics. Important physical processes are charging, sputtering, cooling, light absorption and radiation pressure, connecting electromagnetic forces to gravity. Surface chemistry is another important aspect. In the laboratory there is great interest in industrial processes (e.g. etching, vapor deposition) and at the fundamental physics level - the main topic here - the study of strong coupling phenomena. Here the dust (or microparticles) are the dominant component of the multi-species plasma. The particles can be observed in real time and pace, individually resolved at all relevant length and time scales. This provides an unprecedented means for studying self-organisation processes in many particle systems including the onset of cooperative phenomena. Due to the comparatively large mass of the microparticles (10-12 to 10-9 g) precision experiments are performed on the ISS. The following topics will be discussed: Phase transitions, phase separation, electrorheology, flow phenomena including the onset of turbulence at the kinetic level.
Summary of initial results from the Magnetized Dusty Plasma Experiment (MDPX) device
NASA Astrophysics Data System (ADS)
Thomas, Edward
2015-11-01
Dusty (or complex) plasmas are four-component plasma systems consisting of electrons, ions, neutral atoms and charged, solid particulates. These particulates, i.e., the ``dust,'' become charged through interactions with the surrounding plasma particles and are therefore fully coupled to the background. The study of dusty plasmas began with astrophysical studies and has developed into a distinct area of plasma science with contributions to industrial, space, and fundamental plasma science. However, the vast majority of the laboratory studies are performed without the presence of a magnetic field. This is because, compared to the masses of the electrons and ions, the dust particles are significantly more massive and therefore the charge-to-mass ratio of the dust is very small. As a result, large (B > 1 T) magnetic fields are required to achieve conditions in which the dynamics of electrons, ions, and dust particles are dominated by the magnetic field. This presentation will provide a brief description of the design of the large bore (50 cm diameter x 158 cm long), multi-configuration, 4-Tesla class, superconducting magnet and integrated plasma chamber optimized for the study of dusty plasmas at high magnetic field - the MDPX device. The presentation will then focus on initial results of measurements made using MDPX - including observations of a new type of imposed ordered structures formed by the dust particles in a magnetized plasma, E x B driven flows of the particles, and observations of instabilities. This work is a collaboration of the author with Uwe Konopka (Auburn), Robert L. Merlino (Univ. of Iowa), Marlene Rosenberg (UCSD), and the MDPX team at Auburn University. Construction of the MDPX device was supported by the NSF-MRI program. Operations are supported by the NSF and DOE.
NASA Astrophysics Data System (ADS)
El-Hanbaly, A. M.; El-Shewy, E. K.; Sallah, M.; Darweesh, H. F.
2016-05-01
The nonlinear characteristics of the dust acoustic (DA) waves are studied in a homogeneous, collisionless, unmagnetized, and dissipative dusty plasma composed of negatively charged dusty grains, superthermal electrons, and nonextensive ions. Sagdeev pseudopotential technique has been employed to study the large amplitude DA waves. It (Sagdeev pseudopotential) has an evidence for the existence of compressive and rarefractive solitons. The global features of the phase portrait are investigated to understand the possible types of solutions of the Sagdeev form. On the other hand, the reductive perturbation technique has been used to study small amplitude DA waves and yields the Korteweg-de Vries-Burgers (KdV-Burgers) equation that exhibits both soliton and shock waves. The behavior of the obtained results of both large and small amplitude is investigated graphically in terms of the plasma parameters like dust kinematic viscosity, superthermal and nonextensive parameters.
Dust ion-acoustic solitary waves in a dusty plasma with positive and negative ions
Sayed, F.; Haider, M. M.; Mamun, A. A.; Shukla, P. K.; Eliasson, B.; Adhikary, N.
2008-06-15
Properties of small but finite amplitude dust ion-acoustic (DIA) solitary waves in a dusty plasma composed of inertialess electrons, positive and negative inertial ions, and immobile negative/positive charged dust grains are investigated. By using the multifluid dusty plasma model, the Kortweg-de Vries equation and energy integral for small and large amplitude solitary pulses, are derived. It is found that the presence of the negative ions modifies the properties of the solitary DIA waves, and provides the possibility of positive and negative solitary potential structures to coexist. The present results may be useful for understanding the salient features of localized DIA excitations that may appear in data from forthcoming laboratory experiments and space observations.
Electrostatic solitary structures in dusty plasmas with nonthermal and superthermal electrons
Aoutou, Kamel; Tribeche, Mouloud; Zerguini, Taha Houssine
2008-01-15
A theoretical model is presented to show the existence, formation, and possible realization of arbitrary amplitude solitary potentials in a dusty plasma with both nonthermal and superthermal electrons. A physically meaningful {kappa}-like electron distribution function is outlined. It is shown that due to electron superthermality, the present dusty plasma model can support subsonic as well as supersonic electrostatic solitary waves involving cusped potential humps. Interestingly, one finds that the effect of increasing the spectral index {kappa} is to reduce and restrict the domain of allowable dust Mach numbers. An increase of the nonthermal parameter {alpha} would lead to a shift of this domain and a drastic restriction of the spectral index regime in which compressive and rarefactive solitons can coexist. Our results may provide an explanation for the strong spiky waveforms observed in auroral electric fields measurements by Viking and Fast.
On the existence of vapor-liquid phase transition in dusty plasmas
NASA Astrophysics Data System (ADS)
Kundu, M.; Avinash, K.; Sen, A.; Ganesh, R.
2014-10-01
The phenomenon of phase transition in a dusty-plasma system (DPS) has attracted some attention in the past. Earlier Farouki and Hamaguchi [J. Chem. Phys. 101, 9876 (1994)] have demonstrated the existence of a liquid to solid transition in DPS where the dust particles interact through a Yukawa potential. However, the question of the existence of a vapor-liquid (VL) transition in such a system remains unanswered and relatively unexplored so far. We have investigated this problem by performing extensive molecular dynamics simulations which show that the VL transition does not have a critical curve in the pressure versus volume diagram for a large range of the Yukawa screening parameter κ and the Coulomb coupling parameter Γ. Thus, the VL phase transition is found to be super-critical, meaning that this transition is continuous in the dusty plasma model given by Farouki and Hamaguchi. We provide an approximate analytic explanation of this finding by means of a simple model calculation.
Dust acoustic shock wave in electronegative dusty plasma: Roles of weak magnetic field
Ghosh, Samiran; Ehsan, Z.; Murtaza, G.
2008-02-15
The effects of nonsteady dust charge variations and weak magnetic field on small but finite amplitude nonlinear dust acoustic wave in electronegative dusty plasma are investigated. The dynamics of the nonlinear wave are governed by a Korteweg-de Vries Burger equation that possesses dispersive shock wave. The weak magnetic field is responsible for the dispersive term, whereas nonsteady dust charge variation is responsible for dissipative term, i.e., the Burger term. The coefficient of dissipative term depends only on the obliqueness of the magnetic field. It is found that for parallel propagation the dynamics of the nonlinear wave are governed by the Burger equation that possesses monotonic shock wave. The relevances of the findings to cometary dusty plasma, e.g., Comet Halley are briefly discussed.
On the existence of vapor-liquid phase transition in dusty plasmas
Kundu, M.; Sen, A.; Ganesh, R.; Avinash, K.
2014-10-15
The phenomenon of phase transition in a dusty-plasma system (DPS) has attracted some attention in the past. Earlier Farouki and Hamaguchi [J. Chem. Phys. 101, 9876 (1994)] have demonstrated the existence of a liquid to solid transition in DPS where the dust particles interact through a Yukawa potential. However, the question of the existence of a vapor-liquid (VL) transition in such a system remains unanswered and relatively unexplored so far. We have investigated this problem by performing extensive molecular dynamics simulations which show that the VL transition does not have a critical curve in the pressure versus volume diagram for a large range of the Yukawa screening parameter κ and the Coulomb coupling parameter Γ. Thus, the VL phase transition is found to be super-critical, meaning that this transition is continuous in the dusty plasma model given by Farouki and Hamaguchi. We provide an approximate analytic explanation of this finding by means of a simple model calculation.
Micro Dynamics of Pulsed Laser Induced Bubbles in Dusty Plasma Liquids
Teng, L.-W.; Tsai, C.-Y.; Tseng, Y.-P.; I Lin
2008-09-07
We experimentally study the micro dynamics of the laser induced plasma bubble in a dusty plasma liquid formed by negatively charged dust particles suspended in a low pressure rf Ar glow discharge. The plume from the ablation of the suspended dust particles pushes away dust particle and generates a dust-free plasma bubble. It then travels downward. The spatio-temporal evolution of the dust density fluctuation surrounding the bubble is monitored by directly tracking dust motion through optical video microscopy. The micro dynamics of the bubble associated dust acoustic type solitary oscillation in the wake field is investigated and discussed.
Dust acoustic solitary waves in a charge varying relativistic dusty plasma
Tribeche, Mouloud; Boukhalfa, Soufiane; Zerguini, Taha Houssine
2010-06-15
The problem of nonlinear variable charge dust acoustic solitary waves in dusty plasma with relativistic electrons and ions is addressed. The appropriate relativistic charging currents, derived within the theoretical framework of the orbit-limited motion theory, are used. Our results show that in such a plasma, rarefactive spatially localized dust acoustic waves can exist. Their spatial patterns are significantly modified by the relativistic effects. In particular, it may be noted that relativistic effects make the solitary structure spikier. Our results should help to understand the salient features of coherent nonlinear structures that may occur in relativistic space plasmas.
Dust-acoustic Solitary Waves in Dusty Plasma with Non-thermal Ions
Saini, Nareshpal Singh; Gill, Tarsem Singh; Kaur, Harvinder
2005-10-31
In the present research paper, characteristics of dust-acoustic solitary waves in dusty plasma are studied. The dust charge is treated as variable. KdV equation has been derived using reductive perturbation method. The effect of relative number density, relative ion temperature, non-thermal parameter and variable charge has been numerically studied for possibility of both type of dust-acoustic solitary waves.
Linear study of the nonmodal growth of drift waves in dusty plasmas
Manz, P.; Greiner, F.
2010-06-15
The main effect of dust on drift wave turbulence is the enhancement of the nonadiabaticity. Previous work found that nonmodal behavior is important in the nonadiabatic regime of the drift wave system. Here, the modal and nonmodal properties of the linear Hasegawa-Wakatani system of dusty plasmas are investigated. The non-normality of the linear evolution operator can lead to enhanced transient growth rates compared to the modal growth rates.
Transient bow shock around a cylinder in a supersonic dusty plasma
Meyer, John K.; Merlino, Robert L.
2013-07-15
Visual observations of the formation of a bow shock in the transient supersonic flow of a dusty plasma incident on a biased cylinder are presented. The bow shock formed when the advancing front of a streaming dust cloud was reflected by the obstacle. After its formation, the density jump of the bow shock increased as it moved upstream of the obstacle. A physical picture for the formation of the electrohydrodynamic bow shock is discussed.
Dust-acoustic solitary waves in dusty plasmas with non-thermal ions
Asgari, H.; Muniandy, S. V.; Wong, C. S.
2013-02-15
Most studies on dusty plasmas have assumed that electrons and ions follow Maxwellian distributions. However, in the presence of energetic ions, the distribution of ions tends to be non-Maxwellian. It is shown here that the existence of non-thermal ions would increase the phase velocity of a dust-acoustic wave. It is also found that the change in the phase velocity profoundly affects the characteristics of a dust-acoustic solitary wave.
Nonlinear localized dust acoustic waves in a charge varying dusty plasma with nonthermal ions
Tribeche, Mouloud; Amour, Rabia
2007-10-15
A numerical investigation is presented to show the existence, formation, and possible realization of large-amplitude dust acoustic (DA) solitary waves in a charge varying dusty plasma with nonthermal ions. These nonlinear localized structures are self-consistent solutions of the collisionless Vlasov equation with a population of fast particles. The spatial patterns of the variable charge DA solitary wave are significantly modified by the nonthermal effects. The results complement and provide new insights into previously published results on this problem.
Three-dimensional stereoscopy of Yukawa (Coulomb) balls in dusty plasmas
Kaeding, Sebastian; Melzer, Andre
2006-09-15
A stereoscopic approach with standard video cameras for positioning and tracking of micrometer sized polymer particles in a radio-frequency gas discharge is presented. The stereoscopy is applied to simultaneously determine the positions of all particles in a three-dimensional strongly coupled spherical dusty plasma (Yukawa ball). The accuracy of the stereoscopic method is discussed. The shell structure and the occupation number of various Yukawa balls are determined and compared to recent simulations and models.
Stability of a charged interface between a magnetoradiative dusty plasma and vacuum
Tsintsadze, N. L.; Chaudhary, Rozina; Shah, H. A.; Murtaza, G.
2007-07-15
The stability of a charged surface of a magnetoradiative dusty plasma is investigated. It is shown that for a particular condition, the surface can become unstable through two different mechanisms: one is when the surface is charged, while the other arises due to dissipation instabilities caused by the radiation energy flux. In the linear approximation, a general dispersion relation is derived, taking into account magnetoradiative effect, surface charge, and gravity.
Williams, Jeremiah D.
2011-05-15
Over the past twelve years, two-dimensional and stereoscopic particle image velocimetry (PIV) techniques have been used to obtain detailed measurements of the thermal and transport properties of the microparticle component of dusty plasma systems. This letter reports on an extension of these techniques to obtain a volumetric, three-dimensional velocity vector measurement using tomographic PIV. Initial measurements using the tomographic PIV diagnostic are presented.
Computing the complex : Dusty plasmas in the presence of magnetic fields and UV radiation
NASA Astrophysics Data System (ADS)
Land, V.
2007-12-01
About 90% of the visible universe is plasma. Interstellar clouds, stellar cores and atmospheres, the Solar wind, the Earth's ionosphere, polar lights, and lightning are all plasma; ionized gases, consisting of electrons, ions, and neutrals. Not only many industries, like the microchip and solar cell industry, but also future fusion power stations, rely heavily on the use of plasma. More and more, home appliances include plasma technologies, like compact fluorescent light sources, and plasma screens. Dust particles, which can disrupt plasma processes, enter these plasmas, through chemical reactions in the plasma, or through interactions between plasma and walls. For instance, during microchip fabrication, dust particles can destroy the tiny, nanometre-sized structures on the surface of these chips. On the other hand, dust particles orbiting Young Stellar Objects coagulate and form the seeds of planets. In order to understand fundamental processes, such as planet formation, or to optimize industrial plasma processes, a thorough description of dusty plasma is necessary. Dust particles immersed in plasma collect ions and electrons from the plasma and charge up electrically. Therefore, the presence of dust changes plasma, while at the same time many forces start acting on the dust. Therefore, the dust and plasma become coupled, making dusty plasma a very complex medium to describe, in which many length and time scales play a role, from the Debye length to the length of the electrodes, and from the inverse plasma frequencies to the dust transport times. Using a self-consistent fluid model, we simulate these multi-scale dusty plasmas in radio frequency discharges under micro-gravity. We show that moderate non-linear scattering of ions by the dust particles is the most important aspect in the calculation of the ion drag force. This force is also responsible for the formation of a dust-free 'void' in dusty plasma under micro-gravity, caused by ions moving from the centre of
Perturbed soliton excitations of Rao-dust Alfvén waves in magnetized dusty plasmas
NASA Astrophysics Data System (ADS)
Kavitha, L.; Lavanya, C.; Senthil Kumar, V.; Gopi, D.; Pasqua, A.
2016-04-01
We investigate the propagation dynamics of the perturbed soliton excitations in a three component fully ionized dusty magnetoplasma consisting of electrons, ions, and heavy charged dust particulates. We derive the governing equation of motion for the two dimensional Rao-dust magnetohydrodynamic (R-D-MHD) wave by employing the inertialess electron equation of motion, inertial ion equation of motion, the continuity equations in a plasma with immobile charged dust grains, together with the Maxwell's equations, by assuming quasi neutrality and neglecting the displacement current in Ampere's law. Furthermore, we assume the massive dust particles are practically immobile since we are interested in timescales much shorter than the dusty plasma period, thereby neglecting any damping of the modes due to the grain charge fluctuations. We invoke the reductive perturbation method to represent the governing dynamics by a perturbed cubic nonlinear Schrödinger (pCNLS) equation. We solve the pCNLS, along the lines of Kodama-Ablowitz multiple scale nonlinear perturbation technique and explored the R-D-MHD waves as solitary wave excitations in a magnetized dusty plasma. Since Alfvén waves play an important role in energy transport in driving field-aligned currents, particle acceleration and heating, solar flares, and the solar wind, this representation of R-D-MHD waves as soliton excitations may have extensive applications to study the lower part of the earth's ionosphere.
Longitudinal singular response of dusty plasma medium in weak and strong coupling limits
Kumar Tiwari, Sanat; Das, Amita; Kaw, Predhiman; Sen, Abhijit
2012-01-15
The longitudinal response of a dusty plasma medium in both weak and strong coupling limits has been investigated in detail using analytic as well as numerical techniques. In particular, studies on singular response of the medium have been specifically investigated here. A proper Galilean invariant form of the generalized hydrodynamic fluid model has been adopted for the description of the dusty plasma medium. For weak non-linear response, analytic reductive perturbative approach has been adopted. It is well known that in the weak coupling regime for the dusty plasma medium, such an analysis leads to the Korteweg-de Vries equation (KdV) equation and predicts the existence of localized smooth soliton solutions. We show that the strongly coupled dust fluid with the correct Galilean invariant form does not follow the KdV paradigm. Instead, it reduces to the form of Hunter-Saxton equation, which does not permit soliton solutions. The system in this case displays singular response with both conservative as well as dissipative attributes. At arbitrary high amplitudes, the existence and spontaneous formation of sharply peaked cusp structures in both weak and strong coupling regimes has been demonstrated numerically.
Future lunar missions and investigation of dusty plasma processes on the Moon
NASA Astrophysics Data System (ADS)
Popel, Sergey I.; Zelenyi, Lev M.; Zelenyi
2013-08-01
From the Apollo era of exploration, it was discovered that sunlight was scattered at the terminators giving rise to ``horizon glow'' and ``streamers'' above the lunar surface. Subsequent investigations have shown that the sunlight was most likely scattered by electrostatically charged dust grains originating from the surface. A renaissance is being observed currently in investigations of the Moon. The Luna-Glob and Luna-Resource missions (the latter jointly with India) are being prepared in Russia. Some of these missions will include investigations of lunar dust. Here we discuss the future experimental investigations of lunar dust within the missions of Luna-Glob and Luna-Resource. We consider the dusty plasma system over the lunar surface and determine the maximum height of dust rise. We describe mechanisms of formation of the dusty plasma system over the Moon and its main properties, determine distributions of electrons and dust over the lunar surface, and show a possibility of rising dust particles over the surface of the illuminated part of the Moon in the entire range of lunar latitudes. Finally, we discuss the effect of condensation of micrometeoriod substance during the expansion of the impact plume and show that this effect is important from the viewpoint of explanation of dust particle rise to high altitudes in addition to the dusty plasma effects.
Dusty plasmas over the Moon: theory research in support of the upcoming lunar missions
NASA Astrophysics Data System (ADS)
Popel, Sergey; Zelenyi, Lev; Zakharov, Alexander; Izvekova, Yulia; Dolnikov, Gennady; Dubinskii, Andrey; Kopnin, Sergey; Golub, Anatoly
The future Russian lunar missions Luna 25 and Luna 27 are planned to be equipped with instruments for direct detection of nano- and microscale dust particles and determination of plasma properties over the surface of the Moon. Lunar dust over the Moon is usually considered as a part of a dusty plasma system. Here, we present the main our theory results concerning the lunar dusty plasmas. We start with the description of the observational data on dust particles on and over the surface of the Moon. We show that the size distribution of dust on the lunar surface is in a good agreement with the Kolmogorov distribution, which is the size distribution of particles in the case of multiple crushing. We discuss the role of adhesion which has been identified as a significant force in the dust particle launching process. We evaluate the adhesive force for lunar dust particles with taking into account the roughness and adsorbed molecular layers. We show that dust particle launching can be explained if the dust particles rise at a height of about dozens of nanometers owing to some processes. This is enough for the particles to acquire charges sufficient for the dominance of the electrostatic force over the gravitational and adhesive forces. The reasons for the separation of the dust particles from the surface of the Moon are, in particular, their heating by solar radiation and cooling. We consider migration of free protons in regolith from the viewpoint of the photoemission properties of the lunar soil. Finally, we develop a model of dusty plasma system over the Moon and show that it includes charged dust, photoelectrons, and electrons and ions of the solar wind. We determine the distributions of the photoelectrons and find the characteristics of the dust which rise over the lunar regolith. We show that there are no significant constraints on the Moon landing sites for future lunar missions that will study dusty plasmas in the surface layer of the Moon. We discuss also waves in
Yamamoto, K.; Mizuno, Y.; Hibino, S.; Inuzuka, H.; Cao, Y.; Liu, Y.; Yazawa, K.
2006-01-15
Simulations of dusty plasmas were performed using GRAPE-6, a special-purpose computer designed for gravitational N-body problems. The collective behavior of dust particles, which are injected into the plasma, was studied by means of three-dimensional computer simulations. As an example of a dusty plasma simulation, experiments on Coulomb crystals in plasmas are simulated. Formation of a quasi-two-dimensional Coulomb crystal has been observed under typical laboratory conditions. Another example was to simulate movement of dust particles in plasmas under microgravity conditions. Fully three-dimensional spherical structures of dust clouds have been observed. For the simulation of a dusty plasma in microgravity with 3x10{sup 4} particles, GRAPE-6 can perform the whole operation 1000 times faster than by using a Pentium 4 1.6 GHz processor.
Optical Spectroscopic Diagnostics Of Dusty Plasma In RF Discharge
Orazbayev, S. A.; Jumagulov, M. N.; Dosbolayev, M. K.; Silamiya, M.; Ramazanov, T. S.; Boufendi, L.
2011-11-29
The parameters of the buffer plasma containing dust particles were measured by means of spectroscopic methods. The change in the emission spectrum of the buffer plasma with addition of dust was observed. It seems to relate to changing in temperature and number density of electrons due to the influence of dusts.
Landau damping of the dust-acoustic surface waves in a Lorentzian dusty plasma slab
NASA Astrophysics Data System (ADS)
Lee, Myoung-Jae; Jung, Young-Dae
2016-01-01
Landau damping of a dust-acoustic surface wave propagating at the interfaces of generalized Lorentzian dusty plasma slab bounded by a vacuum is kinetically derived as the surface wave displays the symmetric and the anti-symmetric mode in a plasma slab. In the limiting case of small scaled wave number, we have found that Landau damping is enhanced as the slab thickness is increased. In particular, the damping of anti-symmetric mode is much stronger for a Lorentzian plasma than for a Maxwellian plasma. We have also found that the damping is more affected by superthermal particles in a Lorentzian plasma than by a Maxwellian plasma for both of the symmetric and the anti-symmetric cases. The variations of Landau damping with various parameters are also discussed.
Whispering Gallery Mode Spectroscopy as a Diagnostic for Dusty Plasmas
Thieme, G.; Basner, R.; Ehlbeck, J.; Roepcke, J.; Maurer, H.; Kersten, H.; Davies, P. B.
2008-09-07
Whispering-gallery-mode spectroscopy is being assessed as a diagnostic method for the characterisation of size and chemical composition of spherical particles levitated in a plasma. With a pulsed laser whispering gallery modes (cavity resonances) are excited in individual microspheres leading to enhanced Raman scattering or fluorescence at characteristic wavelengths. This method can be used to gain specific information from the particle surface and is thus of great interest for the characterisation of layers deposited on microparticles, e.g. in molecular plasmas. We present investigations of different microparticles in air and results from fluorescent particles levitated in an Argon rf plasma.
Interaction of nanosecond ultraviolet laser pulses with reactive dusty plasma
NASA Astrophysics Data System (ADS)
van de Wetering, F. M. J. H.; Oosterbeek, W.; Beckers, J.; Nijdam, S.; Gibert, T.; Mikikian, M.; Rabat, H.; Kovačević, E.; Berndt, J.
2016-05-01
Even though UV laser pulses that irradiate a gas discharge are small compared to the plasma volume (≲3%) and plasma-on time (≲6 × 10-6%), they are found to dramatically change the discharge characteristics on a global scale. The reactive argon-acetylene plasma allows the growth of nanoparticles with diameters up to 1 μm, which are formed inside the discharge volume due to spontaneous polymerization reactions. It is found that the laser pulses predominantly accelerate and enhance the coagulation phase and are able to suppress the formation of a dust void.
Propagation modes for a dusty plasma ionization instability under electron beam injection
Donoso, J. M.; Conde, L.
2008-09-07
The low frequency electrostatic linear modes of a dusty plasma penetrated by an energized electron beam are investigated in the frame of a one-dimensional multifluid equations. This plasma contains with thermal and non-thermal electrons, ions and charged dust grains. The stable and unstable modes of the ionization instability are examined in relation to the injected electron beam current density. We pay special attention to the relation of the unstable modes and the injected electron current and ionization cross-section dependence with beam energy, which are proved to be the critical parameters for triggering the instability. This latter could be monitored in the laboratory experiments.
Tunable Diode Laser Absorption Spectroscopy of Metastable Atoms in Dusty Plasmas
Hoang Tung Do; Hippler, Rainer
2008-09-07
Spatial density profile of neon metastable produced in dusty plasma was investigated by means of tunable diode laser absorption spectroscopy. The line averaged measured density drops about 30% with the presence of dust particles. The observations provide evidence for a significant interaction between atoms and powder particles which are important for energy transfer from plasma to particles. The power per unit area absorbed by dust particles due to the collision of metastable atoms with dust particle surface is about some tens of mW/m{sup 2}.
Stability of an elliptical vortex in a strongly coupled dusty plasma
Jana, Sayanee; Banerjee, Debabrata; Chakrabarti, Nikhil
2015-08-15
The stability of a long scale equilibrium vortex structure to short scale perturbations is studied in a strongly coupled dusty plasma in the framework of a generalized hydrodynamic model. It is shown that the free energy associated with the velocity shear of the vortex can drive secondary instabilities consisting of transverse shear waves when the resonance condition between the vortex rotation frequency and the secondary wave frequency is met. Such a process can transfer energy from the long scale vortex to the short scale secondary wave and thereby provide a saturation mechanism for long scale vortices in plasmas in a manner analogous to that in neutral fluids.
NASA Astrophysics Data System (ADS)
El-Bedwehy, N. A.; El-Attafi, M. A.; El-Labany, S. K.
2016-09-01
The properties of solitary waves in an unmagnetized, collisionless dusty plasma consisting of nonthermal ions, cold and hot dust grains and Maxwellian electrons have been investigated. Under a suitable coordinate transformation, the three-dimensional cylindrical Kadomtsev-Petviashvili (3D-CKP) equation is obtained. The effect of the nonthermal parameter, the negative charge number of hot and cold dust on the solitary properties are investigated. Furthermore, the solitary profile in the radial, axial, and polar angle coordinates with the time is examined. The present investigation may be applicable in space plasma such as F-ring of Saturn.
Tribeche, Mouloud; Bacha, Mustapha
2012-12-15
The combined effects of an oblique magnetic field and electron suprathermality on weak dust-acoustic (DA) waves in a charge varying electronegative dusty plasmas with application to the Halley Comet are investigated. The correct suprathermal electron charging current is derived based on the orbit-motion limited approach. A weakly nonlinear analysis is carried out to derive a Korteweg-de Vries-Burger equation. The electron suprathermality, the obliqueness, and magnitude of the magnetic field are found to modify the dispersive properties of the DA shock structure. Our results may aid to explain and interpret the nonlinear oscillations that may occur in the Halley Comet plasma.
Weakly nonlinear dust ion-acoustic shock waves in a dusty plasma with nonthermal electrons
Berbri, Abderrezak; Tribeche, Mouloud
2009-05-15
Weakly nonlinear dust ion-acoustic (DIA) shock waves are investigated in a dusty plasma with nonthermal electrons. A modified Korteweg-de Vries equation with a cubic nonlinearity is derived. Due to the net negative dust charge {mu}Z{sub d} and electron nonthermality, the present plasma model can admit compressive and rarefactive weak DIA shock waves. The effect of increasing {mu}Z{sub d} is to lower the critical nonthermal parameter {beta}{sub c} above which only rarefactive DIA shock waves are admitted. Our investigation may help to understand the nonlinear structures observed in the auroral acceleration regions.
Effects of the relative motion of different particles on the wave instability in dusty plasmas
Gao, Dong-Ning; Hong, Xue-Ren; Lin, Mai-mai; Han, Juan-fang; Duan, Wen-shan; Yang, Lei
2014-06-15
Theoretical study is carried out for the dust acoustic waves in a dusty plasma. The dispersion relation is obtained from the fluid dynamical model. It is found that the wave frequency depends on the electron number density, wave number, and the speed of electrons or ions. The dependencies of the instability on the system parameters are also discussed. It is found that the long wavelength wave is usually unstable, which may be useful in the plasma physics, especially in the magnetic confined fusion system or the charged beam dynamics in the accelerated driven system.
Collective Modes in Strongly Correlated Yukawa Liquids: Waves in Dusty Plasmas
Kalman, G.; Rosenberg, M.; DeWitt, H. E.
2000-06-26
We determine the collective mode structure of a strongly correlated Yukawa fluid, with the purpose of analyzing wave propagation in a strongly coupled dusty plasma. We identify a longitudinal plasmon and a transverse shear mode. The dispersion is characterized by a low-k acoustic behavior, a frequency maximum well below the plasma frequency, and a high-k merging of the two modes around the Einstein frequency of localized oscillations. The damping effect of collisions between neutrals and dust grains is estimated. (c) 2000 The American Physical Society.
Maitra, Sarit; Banerjee, Gadadhar
2014-11-15
The influence of dust size distribution on the dust ion acoustic solitary waves in a collisional dusty plasma is investigated. It is found that dust size distribution changes the amplitude and width of a solitary wave. A critical wave number is derived for the existence of purely damping mode. A deformed Korteweg-de Vries (dKdV) equation is obtained for the propagation of weakly nonlinear dust ion acoustic solitary waves and the effect of different plasma parameters on the solution of this equation is also presented.
Ion wake effects on the Coulomb ion drag in complex dusty plasmas
Ki, Dae-Han; Jung, Young-Dae
2010-09-06
The ion wake effects on the Coulomb drag force are investigated in complex dusty plasmas. It is shown that the ion wake effects significantly enhance the Coulomb ion drag force. It is also found that the ion wake effects on the Coulomb drag force increase with an increase in the Debye length. In addition, the ion wake effects on the momentum transfer cross section and Coulomb drag force are found to be increased with increasing thermal Mach number, i.e., decreasing plasma temperature. It is also found that the Coulomb ion drag force would be stronger for smaller dust grains.
Stability of an elliptical vortex in a strongly coupled dusty plasma
NASA Astrophysics Data System (ADS)
Jana, Sayanee; Banerjee, Debabrata; Chakrabarti, Nikhil
2015-08-01
The stability of a long scale equilibrium vortex structure to short scale perturbations is studied in a strongly coupled dusty plasma in the framework of a generalized hydrodynamic model. It is shown that the free energy associated with the velocity shear of the vortex can drive secondary instabilities consisting of transverse shear waves when the resonance condition between the vortex rotation frequency and the secondary wave frequency is met. Such a process can transfer energy from the long scale vortex to the short scale secondary wave and thereby provide a saturation mechanism for long scale vortices in plasmas in a manner analogous to that in neutral fluids.
NASA Astrophysics Data System (ADS)
Thomas, Edward; Konopka, Uwe; Merlino, Robert L.; Rosenberg, Marlene
2016-05-01
The Magnetized Dusty Plasma Experiment at Auburn University has been operational for over one year. In that time, a number of experiments have been performed at magnetic fields up to B = 2.5 T to explore the interaction between magnetized plasmas and charged, micron-sized dust particles. This paper reports on the initial results from studies of: (a) the formation of imposed, ordered structures, (b) the properties of dust wave waves in a rotating frame, and (c) the generation of plasma filaments.
Interaction of energetic electrons with dust whistler-mode waves in magnetospheric dusty plasmas
NASA Astrophysics Data System (ADS)
Jafari, S.
2016-04-01
In this Letter, a new conceptual approach has been presented to investigate the interaction of energetic electrons with dust whistler-mode waves in magnetospheric dusty (complex) plasmas. Dust whistler-mode waves generated in the presence of charged dust grains in the magnetized dusty plasma, can scatter the launched electrons into the loss-cone leading to precipitation into the upper atmosphere which is an important loss process in the radiation belts and provides a major source of energy for the diffuse and pulsating aurora. To study the scattered electrons and chaotic regions, a Hamiltonian model of the electron-dust wave interaction has been employed in the magnetospheric plasma by considering the launched electron beam self-fields. Numerical simulations indicate that an electron beam interacting with the whistler-mode wave can easily trigger chaos in the dust-free plasma, while in the presence of dust charged grains in the plasma, the chaotic regions are quenched to some extent in the magnetosphere. Consequently, the rate of scattered electrons into the loss-cone reduces for the regions that the dust grains are present.
Vortices of self-gravitating grains in dusty plasmas
Nebbat, E.; Annou, R.
2012-09-15
Vortices are an attractive expression of the non-linear dynamics of fluids along with plasmas. In complex plasmas, Nebbat and Annou [Phys. Plasmas 17, 093702 (2010)] proposed a time dependent non-linear model that considers vortices as a consequence of an instability. The model is augmented hereafter by incorporating the gravitational grain-grain attraction, particle drift due to self-gravity field, self-consistent inter-particle distance, the permeability of grains along with the grain charge excess due to the non-linear dependence of the grain capacitance on its size. Effects of the latter parameters as well as the effect of grain mass to charge ratio on the characteristics of the vortex such as density are investigated.
Experimental study of interacting solitons in a complex (dusty) plasma
NASA Astrophysics Data System (ADS)
Harvey, Paul; Samsonov, Dmitry; Morfill, Gregor
2008-11-01
A plasma is an ionised gas which consists of a mixture of electrons, positive ions and neutral molecules. In complex plasmas, small micron-sized microspheres are introduced. The grains become negatively charged and form a monolayer lattice. A soliton is a stable, solitary wave that retains its shape as it propagates through a medium. The apparatus for this experiment consists of a discharge chamber containing two electrodes. The lower electrode delivers RF-power into the chamber, maintaining the argon gas in the plasma state. The particles are confined radially within a bowl-shaped potential. Two parallel wires run along opposite sides of the monolayer lattice. A negative pulse on both wires excites two solitons to propagate inwards. A thin sheet of laser light illuminates the lattice which is then captured on video at a high frame rate. The kinetic movement of the microspheres can then be analysed. The propagation of the two solitons through this crystal lattice has been traced. Interaction has been observed to occur between two soliton waves within the complex plasma.
Dusty plasma cavities: Probe-induced and natural
NASA Astrophysics Data System (ADS)
Harris, B. J.; Matthews, L. S.; Hyde, T. W.
2015-06-01
A comprehensive exploration of regional dust evacuation in complex plasma crystals is presented. Voids created in three-dimensional crystals on the International Space Station have provided a rich foundation for experiments, but cavities in dust crystals formed in ground-based experiments have not received as much attention. Inside a modified Gaseous Electronics Conference rf cell, a powered vertical probe was used to clear the central area of a dust crystal, producing a cavity with high cylindrical symmetry. Cavities generated by three mechanisms are examined. First, repulsion of micrometer-sized particles by a negatively charged probe is investigated. A model of this effect developed for a dc plasma is modified and applied to explain experimental data in rf plasma. Second, the formation of natural cavities is surveyed; a radial ion drag proposed to occur due to a curved sheath is considered in conjunction with thermophoresis and a flattened confinement potential above the center of the electrode. Finally, cavity formation upon increasing the probe potential above the plasma floating potential is justified by a combination of ion drag and sheath edge modification. The cavities produced by these methods appear similar, but each is shown to be facilitated by fundamentally different processes.
Dusty plasma cavities: Probe-induced and natural.
Harris, B J; Matthews, L S; Hyde, T W
2015-06-01
A comprehensive exploration of regional dust evacuation in complex plasma crystals is presented. Voids created in three-dimensional crystals on the International Space Station have provided a rich foundation for experiments, but cavities in dust crystals formed in ground-based experiments have not received as much attention. Inside a modified Gaseous Electronics Conference rf cell, a powered vertical probe was used to clear the central area of a dust crystal, producing a cavity with high cylindrical symmetry. Cavities generated by three mechanisms are examined. First, repulsion of micrometer-sized particles by a negatively charged probe is investigated. A model of this effect developed for a dc plasma is modified and applied to explain experimental data in rf plasma. Second, the formation of natural cavities is surveyed; a radial ion drag proposed to occur due to a curved sheath is considered in conjunction with thermophoresis and a flattened confinement potential above the center of the electrode. Finally, cavity formation upon increasing the probe potential above the plasma floating potential is justified by a combination of ion drag and sheath edge modification. The cavities produced by these methods appear similar, but each is shown to be facilitated by fundamentally different processes. PMID:26172806
2-D Imaging of Electron Temperature in Tokamak Plasmas
T. Munsat; E. Mazzucato; H. Park; C.W. Domier; M. Johnson; N.C. Luhmann Jr.; J. Wang; Z. Xia; I.G.J. Classen; A.J.H. Donne; M.J. van de Pol
2004-07-08
By taking advantage of recent developments in millimeter wave imaging technology, an Electron Cyclotron Emission Imaging (ECEI) instrument, capable of simultaneously measuring 128 channels of localized electron temperature over a 2-D map in the poloidal plane, has been developed for the TEXTOR tokamak. Data from the new instrument, detailing the MHD activity associated with a sawtooth crash, is presented.
NASA Astrophysics Data System (ADS)
Zaghbeer, S. K.; Salah, H. H.; Sheta, N. H.; El-Shewy, E. K.; Elgarayhi, A.; Elgarayhi
2014-03-01
A theoretical investigation has been made of obliquely propagating nonlinear electrostatic shock structures. The reductive perturbation method has been used to derive the Korteweg-de Vries-Burger (KdV-Burger) equation for dust acoustic shock waves in a homogeneous system of a magnetized collisionless plasma comprising a four-component dusty plasma with massive, micron-sized, positively, negatively dust grains and non-extensive electrons and ions. The effect of dust viscosity coefficients of charged dusty plasma of opposite polarity and the non-extensive parameters of electrons and ions have been studied. The behavior of the oscillatory and monotonic shock waves in dusty plasma has been investigated. It has been found that the presence of non-extensive parameters significantly modified the basic properties of shock structures in space environments.
NASA Astrophysics Data System (ADS)
Zhukhovitskii, Dmitry I.; Petrov, Oleg F.; Hyde, Truell W.; Herdrich, Georg; Laufer, Rene; Dropmann, Michael; Matthews, Lorin S.
2015-05-01
We discuss the inductively heated plasma generator (IPG) facility in application to the generation of the thermal dusty plasma formed by the positively charged dust particles and the electrons emitted by them. We develop a theoretical model for the calculation of plasma electrical conductivity under typical conditions of the IPG. We show that the electrical conductivity of dusty plasma is defined by collisions with the neutral gas molecules and by the electron number density. The latter is calculated in the approximations of an ideal and strongly coupled particle system and in the regime of weak and strong screening of the particle charge. The maximum attainable electron number density and corresponding maximum plasma electrical conductivity prove to be independent of the particle emissivity. Analysis of available experiments is performed, in particular, of our recent experiment with plasma formed by the combustion products of a propane-air mixture and the CeO2 particles injected into it. A good correlation between the theory and experimental data points to the adequacy of our approach. Our main conclusion is that a level of the electrical conductivity due to the thermal ionization of the dust particles is sufficiently high to compete with that of the potassium-doped plasmas.
Melting scenarios for three-dimensional dusty plasma clusters
NASA Astrophysics Data System (ADS)
Schella, André; Miksch, Tobias; Melzer, André; Schablinski, Jan; Block, Dietmar; Piel, Alexander; Thomsen, Hauke; Ludwig, Patrick; Bonitz, Michael
2011-11-01
The melting transition of finite three-dimensional dust clouds (Yukawa balls) from a solid-like to a liquid-like state is systematically studied with high spatial and temporal resolution of the individual grains by means of stereoscopy. Two different melting scenarios are reported: Melting is induced first by an increase of plasma power, and second by laser-induced heating. The experiments confirm that melting starts with a loss of orientational correlation, followed by a loss of the radial order upon further heating. While the plasma-power melting is driven via the ion wakefield, laser heating provides a more equilibrium scenario. The internal loss of correlations is well captured by the triple correlation function (TCF) which is insensitive to particle exchanges and the rotation of the cluster as a whole. The critical Coulomb coupling parameter for N=35 is determined as Γcrit≈570. The experimental findings are in good agreement with thermodynamic Monte Carlo simulations.
Dust Acoustic Solitons in the Dusty Plasma of the Earth's Ionosphere
Kopnin, S.I.; Kosarev, I.N.; Popel, S.I.; Yu, M.Y.
2005-03-15
Stratified structures that are observed at heights of 80-95 km in the lower part of the Earth's ionosphere are known as noctilucent clouds and polar mesosphere summer echoes. These structures are thought to be associated with the presence of vast amounts of charged dust or aerosols. The layers in the lower ionosphere where there are substantial amounts of dust are called the dusty ionosphere. The dust grains can carry a positive or a negative charge, depending on their constituent materials. As a rule, the grains are ice crystals, which may contain metallic inclusions. A grain with a sufficiently large metallic content can acquire a positive charge. Crystals of pure ice are charged negatively. The distribution of the dust grains over their charges has a profound impact on the ionizational and other properties of dust structures in the dusty ionosphere. In the present paper, a study is made of the effect of the sign of the dust charge on the properties of dust acoustic solitons propagating in the dusty ionosphere. It is shown that, when the dust charge is positive, dust acoustic solitons correspond to a hill in the electron density and a well in the ion density. When the dust is charged negatively, the situation is opposite. These differences in the properties of dust acoustic solitons can be used to diagnose the plasmas of noctilucent clouds and polar mesosphere summer echoes.
Rayleigh-Taylor instability in dusty plasma experiment
Avinash, K.; Sen, A.
2015-08-15
The stability of a stratified dust cloud levitated in an anodic plasma is studied in the weakly and strongly coupled dust regimes. It is shown that the cloud is predominantly unstable to a Rayleigh-Taylor (RT) instability driven by a component of the ambient gravity in a direction opposite to the direction of dust density stratification in the cloud. The elasticity of the strongly coupled dust is shown to set a threshold for the RT instability, which is consistent with experimental observations.
Mechanism behind self-sustained oscillations in direct current glow discharges and dusty plasmas
Cho, Sung Nae
2013-04-15
An alternative explanation to the mechanism behind self-sustained oscillations of ions in direct current (DC) glow discharges is provided. Such description is distinguished from the one provided by the fluid models, where oscillations are attributed to the positive feedback mechanism associated with photoionization of particles and photoemission of electrons from the cathode. Here, oscillations arise as consequence of interaction between an ion and the surface charges induced by it at the bounding electrodes. Such mechanism provides an elegant explanation to why self-sustained oscillations occur only in the negative resistance region of the voltage-current characteristic curve in the DC glow discharges. Furthermore, this alternative description provides an elegant explanation to the formation of plasma fireballs in the laboratory plasma. It has been found that oscillation frequencies increase with ion's surface charge density, but at the rate which is significantly slower than it does with the electric field. The presented mechanism also describes self-sustained oscillations of ions in dusty plasmas, which demonstrates that self-sustained oscillations in dusty plasmas and DC glow discharges involve common physical processes.
NASA Astrophysics Data System (ADS)
Alam, M. S.; Masud, M. M.; Mamun, A. A.
2015-02-01
The basic properties of nonplanar (viz. cylindrical and spherical) dust-ion-acoustic (DIA) shock waves in an unmagnetized dusty plasma system [consisting of inertial ions, negatively charged immobile dust, and superthermal electrons with two distinct temperatures] are investigated by employing the reductive perturbation method. The modified Burgers equation is derived and is numerically analyzed in order to examine the basic properties of DIA shock structures. The effects of nonplanar geometry, electron superthermality, and ion kinematic viscosity on the basic features of DIA shock waves are discussed. It is found that the properties of the cylindrical and spherical DIA shock waves in dusty plasmas with two-temperature superthermal electrons significantly differ from those of one-dimensional planar shocks. The implications of our results in space plasmas [viz. star formation, supernovae explosion, solar wind, pulsar magnetosphere, Saturn's outer magnetosphere (R ˜13-18 R S , where R S is the radius of Saturn), Saturn's inner magnetosphere (R <9 R S , etc.)] and laboratory plasmas (viz. laser-induced implosion, capsule implosion, shock tube, etc.), where superthermal electrons with two distinct temperatures occurs, are briefly discussed.
NASA Astrophysics Data System (ADS)
Khan, Shahab Ullah; Adnan, Muhammad; Qamar, Anisa; Mahmood, Shahzad
2016-07-01
The propagation of linear and nonlinear electrostatic waves is investigated in magnetized dusty plasma with stationary negatively or positively charged dust, cold mobile ions and non-extensive electrons. Two normal modes are predicted in the linear regime, whose characteristics are investigated parametrically, focusing on the effect of electrons non-extensivity, dust charge polarity, concentration of dust and magnetic field strength. Using the reductive perturbation technique, a Zakharov-Kuznetsov (ZK) type equation is derived which governs the dynamics of small-amplitude solitary waves in magnetized dusty plasma. The properties of the solitary wave structures are analyzed numerically with the system parameters i.e. electrons non-extensivity, concentration of dust, polarity of dust and magnetic field strength. Following Allen and Rowlands (J. Plasma Phys. 53:63, 1995), we have shown that the pulse soliton solution of the ZK equation is unstable, and have analytically traced the dependence of the instability growth rate on the nonextensive parameter q for electrons, dust charge polarity and magnetic field strength. The results should be useful for understanding the nonlinear propagation of DIA solitary waves in laboratory and space plasmas.
Electrical conductivity of the dusty plasma in the Enceladus plume
NASA Astrophysics Data System (ADS)
Yaroshenko, V. V.; Lühr, H.
2016-11-01
The plasma conductivity is an important issue for understanding the magnetic field structure registered by Cassini in the Enceladus proximity. We have revise the conductivity mechanism to incorporate the plume nanograins as a new plasma species and take into account the relevant collisional processes including those accounting for the momentum exchange between the charged dust and co-rotating ions. It is concluded that in the Enceladus plume the dust dynamics affects the Pedersen and Hall conductivity more efficiently than the electron depletion associated with the presence of the negatively charged dust as has been suggested by Simon et al. (Simon, S., Saur, J., Kriegel, H., Neubauer, F. M., Motschmann, U., and Dougherty, U. [2011] J. Geophys. Res., 116, A04221, doi:10.1029/2010JA016338). The electron depletion remains a decisive factor for only the parallel conductivity. In the parameter regime relevant for the Enceladus plume, one finds increase of the Pedersen and decrease of the parallel components, whereas for the Hall conductivity the charged dust changes both - its value and the sign. The associated reversed Hall effect depends significantly upon the local dust-to-plasma density ratio. An onset of the reversed Hall effect appears to be restricted to outer parts of the Enceladus plume. The results obtained can significantly modify Enceladus' Alfvén wing structure and thus be useful for interpretations of the magnetic field perturbations registered by the Cassini Magnetometer during the close Enceladus flybys.
Solitary and freak waves in a dusty plasma with negative ions
Abdelsalam, U. M.; Moslem, W. M.; Khater, A. H.; Shukla, P. K.
2011-09-15
It is shown that solitary and freak waves can propagate in a dusty plasma composed of positive and negative ions, as well as nonextensive electrons. The evolution of the solitary waves is described by the Korteweg-de Vries (KdV) equation. However, when the frequency of the carrier wave is much smaller than the ion plasma frequency then the KdV equation is also used to study the nonlinear evolution of modulationally unstable modified ion-acoustic wavepackets through the derivation of the nonlinear Schroedinger (NLS) equation. In order to show that the characteristics of the solitary and freak waves are influenced by the plasma parameters, the relevant numerical analysis of the appropriate nonlinear solutions is presented. The relevance of the present investigation to nonlinear waves in astrophysical plasma environments is discussed.
Modification and damping of Alfven waves in a magnetized dusty plasma
NASA Astrophysics Data System (ADS)
Salimullah, M.; Dasgupta, B.; Watanabe, K.; Sato, T.
1994-10-01
The dispersion characteristics of the circularly polarized electromagnetic waves along a homogeneous magnetic field in a dusty plasma have been investigated theoretically. The Vlasov equation has been employed to find the response of the magnetized plasma particles where the dust grains form a static background of highly charged and massive centers having certain correlations. It is found that in addition to the unusual Landau damping, which is negligible in the low temperature approximation, a novel mechanism of damping of the Alfven waves due to the dust comes into play. The modification and damping of the Alfven waves depend on the dust perturbation parameters, unequal densities of plasma particles, the average correlation length of the dust grains, temperature of the plasma and the magnetic field.
Trapping effects in a self-gravitating quantum dusty plasma
NASA Astrophysics Data System (ADS)
Ayub, M.; Shah, H. A.; Qureshi, M. N. S.
2011-10-01
The effects of trapping on the nonlinear properties of dust-acoustic waves in an unmagnitized collisionless self-gravitating plasma were studied by treating the ions to be Maxwellian, the dust to be cold and the electrons to be degenerate. The effect of trapping and the gravitational potential on the nonlinear structures was investigated by employing the Sagdeev potential approach, which shows that the features of solitary wave structures are affected by changes in Mach number as well as ion temperature and other physical parameters of the system. Modulational stability analysis is also presented, and the regions of stability and instability are discussed.
Debye Shielding and Particle Correlations in Strongly Coupled Dusty Plasmas
Otani, N.; Bhattacharjee, A.
1997-02-01
A particle-in-cell simulation method is shown effective in modeling strongly coupled plasmas, exhibiting good energy conservation properties and good resolution of the dust-particle interaction. For coupling parameters of order unity, the simulation dust particles exhibit Debye shielding on the spatial scale of the dust Debye length. When initialized with a large coupling parameter, the dust particles do not organize themselves into a crystalline structure as expected, but instead are scattered by the presence of substantial electrostatic wave activity. Liquid-like or crystal-like correlations among the dust particles occur only when annealing is imposed. {copyright} {ital 1997} {ital The American Physical Society}
Laser-induced incandescence applied to dusty plasmas
NASA Astrophysics Data System (ADS)
van de Wetering, F. M. J. H.; Oosterbeek, W.; Beckers, J.; Nijdam, S.; Kovačević, E.; Berndt, J.
2016-07-01
This paper reports on the laser heating of nanoparticles (diameters ≤slant 1 μm) confined in a reactive plasma by short (150 ps) and intense (∼ 63 mJ) UV (355 nm) laser pulses (laser-induced incandescence, LII). Important parameters such as the particle temperature and radius follow from analysis of the emission spectrum of the heated nanoparticles. The nanoparticles are not ideal black bodies, which is taken into account by calculating their emissivity using a light-scattering theory relevant to our conditions (Mie theory). Three sets of refractive index data from the literature serve as model input. The obtained radii range between 100 and 165 nm, depending on the choice of refractive index data set. By fitting the temperature decay of the particles to a heat exchange model, the product of their mass density and specific heat is determined as (1.3+/- 0.5) J K‑1 cm‑3, which is considerably smaller than the value for bulk graphite at the temperature our particles attain (3000 K): 4.8 J K‑1 cm‑3. The particle sizes obtained in situ with LII are compared with ex situ scanning electron microscopy analysis of collected particles. Quantitative assessment of the LII measurements is hampered by transport of particles in the plasma volume and the fact that LII probes locally, whereas the samples with collected particles have a more global character.
Melting scenarios for three-dimensional dusty plasma clusters
Schella, Andre; Miksch, Tobias; Melzer, Andre; Schablinski, Jan; Block, Dietmar; Piel, Alexander; Thomsen, Hauke; Ludwig, Patrick; Bonitz, Michael
2011-11-15
The melting transition of finite three-dimensional dust clouds (Yukawa balls) from a solid-like to a liquid-like state is systematically studied with high spatial and temporal resolution of the individual grains by means of stereoscopy. Two different melting scenarios are reported: Melting is induced first by an increase of plasma power, and second by laser-induced heating. The experiments confirm that melting starts with a loss of orientational correlation, followed by a loss of the radial order upon further heating. While the plasma-power melting is driven via the ion wakefield, laser heating provides a more equilibrium scenario. The internal loss of correlations is well captured by the triple correlation function (TCF) which is insensitive to particle exchanges and the rotation of the cluster as a whole. The critical Coulomb coupling parameter for N=35 is determined as {Gamma}{sub crit}{approx_equal}570. The experimental findings are in good agreement with thermodynamic Monte Carlo simulations.
Wave processes in dusty plasma near the Moon's surface
NASA Astrophysics Data System (ADS)
Morozova, T. I.; Kopnin, S. I.; Popel, S. I.
2015-10-01
A plasma—dust system in the near-surface layer on the illuminated side of the Moon is described. The system involves photoelectrons, solar-wind electrons and ions, neutrals, and charged dust grains. Linear and nonlinear waves in the plasma near the Moon's surface are discussed. It is noticed that the velocity distribution of photoelectrons can be represented as a superposition of two distribution functions characterized by different electron temperatures: lower energy electrons are knocked out of lunar regolith by photons with energies close to the work function of regolith, whereas higher energy electrons are knocked out by photons corresponding to the peak at 10.2 eV in the solar radiation spectrum. The anisotropy of the electron velocity distribution function is distorted due to the solar wind motion with respect to photoelectrons and dust grains, which leads to the development of instability and excitation of high-frequency oscillations with frequencies in the range of Langmuir and electromagnetic waves. In addition, dust acoustic waves can be excited, e.g., near the lunar terminator. Solutions in the form of dust acoustic solitons corresponding to the parameters of the dust—plasma system in the near-surface layer of the illuminated Moon's surface are found. Ranges of possible Mach numbers and soliton amplitudes are determined.
Active interrogation of plasma-liquid boundary using 2D plasma-in-liquid apparatus
NASA Astrophysics Data System (ADS)
Lai, Janis; Foster, John
2015-09-01
Plasma medicine and plasma-based water purification technologies rely on the production and transport of plasma-derived (direct or indirect) reactive species into the bulk medium. This interaction takes place at the interface between the gas phase plasma and the liquid medium. The nature of radical production and subsequent radical transport from this region or boundary layer is not well understood due to the difficulty of implementing diagnostics to interrogate this region. We present a 2-D plasma-in-liquid water apparatus that makes the interface region assessable to optical diagnostics. Using colorimetric chemical probes, acidification and oxidation fronts are tracked using high-speed imaging and spectroscopy. Additionally, observed, plasma-induced fluid dynamical effects are also discussed. Forces at the interface can play a key role in the transport of radicals into the bulk solution. The role of plasma-driven interfacial forces as well as that of the applied, local electric field on chemical front propagation velocity and induced circulation are also discussed. Supported by grants NSF CBET 1336375 and DOE DE-SC0001939.
Damping of dust-acoustic waves due to dust-dust interactions in dusty plasmas
NASA Astrophysics Data System (ADS)
de Angelis, U.; Shukla, P. K.
1998-08-01
The results of a kinetic model are presented which includes dust-dust collisions as a damping mechanism for the low-phase velocity dust-acoustic waves which have been observed [Pieper and Goree, Phys. Rev. Lett. 77 (1976) 3137] in a dusty plasma device. A comparison of our theoretical results with those of observations exhibits a good agreement, and it also leads to quantitative estimates that are close to the predictions of the modified fluid theory, which has introduced a damping rate in an ad hoc manner.
Envelope solitary waves exist and collide head-on without phase shift in a dusty plasma
Zhang, Heng; Qi, Xin; Duan, Wen-Shan; Yang, Lei
2015-01-01
The rarefactive KdV solitary waves in a dusty plasma have been extensively studied analytically and found experimentally in the previous works. Though the envelope solitary wave described by a nonlinear Schrödinger equation (NLSE) has been proposed by using the reductive perturbation method, it is first verified by using the particle-in-cell (PIC) numerical method in this paper. Surprisingly, there is no phase shift after the head on collision between two envelope solitary waves, while it is sure that there are phase shifts of two colliding KdV solitary waves after head on collision. PMID:26383642
Shock wave in magnetized dusty plasmas with dust charging and nonthermal ion effects
Zhang Liping; Xue Jukui
2005-04-15
The effects of the external magnetized field, nonadiabatic dust charge fluctuation, and nonthermally distributed ions on three-dimensional dust acoustic shock wave in dusty plasmas have been investigated. By using the reductive perturbation method, a Korteweg-de Vries (KdV) Burger equation governing the dust acoustic shock wave is derived. The results of numerical integrations of KdV Burger equation show that the external magnetized field, nonthermally distributed ions, and nonadiabatic dust charge fluctuation have strong influence on the shock structures.
Envelope solitary waves exist and collide head-on without phase shift in a dusty plasma.
Zhang, Heng; Qi, Xin; Duan, Wen-Shan; Yang, Lei
2015-01-01
The rarefactive KdV solitary waves in a dusty plasma have been extensively studied analytically and found experimentally in the previous works. Though the envelope solitary wave described by a nonlinear Schrödinger equation (NLSE) has been proposed by using the reductive perturbation method, it is first verified by using the particle-in-cell (PIC) numerical method in this paper. Surprisingly, there is no phase shift after the head on collision between two envelope solitary waves, while it is sure that there are phase shifts of two colliding KdV solitary waves after head on collision. PMID:26383642
Shahmansouri, M.; Alinejad, H.
2015-04-15
We give a theoretical investigation on the dynamics of nonlinear electrostatic waves in a strongly coupled dusty plasma with strong electrostatic interaction between dust grains in the presence of the polarization force (i.e., the force due to the polarized Debye sheath). Adopting a reductive perturbation method, we derived a three-dimensional Kadomtsev-Petviashvili equation that describes the evolution of weakly nonlinear electrostatic localized waves. The energy integral equation is used to study the existence domains of the localized structures. The analysis provides the localized structure existence region, in terms of the effects of strong interaction between the dust particles and polarization force.
Arp, O.; Caliebe, D.; Piel, A.
2011-06-15
The penetration of a projectile into a strongly coupled dusty plasma was studied in a radio-frequency discharge under microgravity conditions. A supersonic projectile produces an elongated dust-free cavity in its wake. The dynamics of the cavity is analyzed and compared with Langevin dynamics simulations. Besides a three-dimensional Mach cone structure, the simulation shows that the cavity dynamics can be subdivided into three phases: An opening phase with fixed time scale, a closing phase, whose duration is affected by the projectile speed and, finally, a phase of particle realignment in the target cloud, which persists for a long time after the closure of the cavity.
Phenomena associated with complex (dusty) plasmas in the ionosphere during high-speed meteor showers
Kopnin, S. I.; Popel, S. I.; Yu, M. Y.
2009-06-15
Formation of dusty plasmas in the Earth's ionosphere at 80-120 km altitudes during high-speed meteor showers and its detectable manifestations are discussed. Emphasis is given to ground-based observations such as detection of low-frequency (<50 Hz) ionospheric radio noise, ground-based observations of infrasonic waves, and amplification of the intensity of green radiation at 557.7 nm from a layer at the 110-120 km altitude in the lower ionosphere. The physical processes responsible for these manifestations are considered.
El-Labany, S. K. Zedan, N. A.; El-Taibany, W. F. E-mail: eltaibany@du.edu.eg
2015-07-15
Cylindrical and spherical amplitude modulations of dust acoustic (DA) solitary wave envelopes in a strongly coupled dusty plasma containing nonthermal distributed ions are studied. Employing a reductive perturbation technique, a modified nonlinear Schrödinger equation including the geometrical effect is derived. The influences of nonthermal ions, polarization force, and the geometries on the modulational instability conditions are analyzed and the possible rogue wave structures are discussed in detail. It is found that the spherical DA waves are more structurally stable to perturbations than the cylindrical ones. Possible applications of these theoretical findings are briefly discussed.
Molecular dynamics simulations of soliton-like structures in a dusty plasma medium
Tiwari, Sanat Kumar Das, Amita; Sen, Abhijit; Kaw, Predhiman
2015-03-15
The existence and evolution of soliton-like structures in a dusty plasma medium are investigated in a first principles approach using molecular dynamic (MD) simulations of particles interacting via a Yukawa potential. These localized structures are found to exist in both weakly and strongly coupled regimes with their structures becoming sharper as the correlation effects between the dust particles get stronger. A surprising result, compared to fluid simulations, is the existence of rarefactive soliton-like structures in our non-dissipative system, a feature that arises from the charge conjugation symmetry property of the Yukawa fluid. Our simulation findings closely resemble many diverse experimental results reported in the past.
Oblique collision of dust acoustic solitons in a strongly coupled dusty plasma
Boruah, A.; Sharma, S. K. Bailung, H.; Nakamura, Y.
2015-09-15
The oblique collision between two equal amplitude dust acoustic solitons is observed in a strongly coupled dusty plasma. The solitons are subjected to oblique interaction at different colliding angles. We observe a resonance structure during oblique collision at a critical colliding angle which is described by the idea of three wave resonance interaction modeled by Kadomtsev-Petviashvili equation. After collision, the solitons preserve their identity. The amplitude of the resultant wave formed during interaction is measured for different collision angles as well as for different colliding soliton amplitudes. At resonance, the maximum amplitude of the new soliton formed is nearly 3.7 times the initial soliton amplitude.
Coupling of dust acoustic and shear mode through velocity shear in a strongly coupled dusty plasma
Garai, S. Janaki, M. S.; Chakrabarti, N.
2015-07-15
In the strongly coupled limit, the generalized hydrodynamic model shows that a dusty plasma, acquiring significant rigidity, is able to support a “shear” like mode. It is being demonstrated here that in presence of velocity shear gradient, this shear like mode gets coupled with the dust acoustic mode which is generated by the compressibility effect of the dust fluid due to the finite temperatures of the dust, electron, and ion fluids. In the local analysis, the dispersion relation shows that velocity shear gradient not only couples the two modes but is also responsible for the instabilities of that coupled mode which is confirmed by nonlocal analysis with numerical techniques.
Correlation effects due to an axial propagation of projectiles in a dusty plasma
Ali, S.; Nasim, M.H.; Murtaza, G.
2005-03-01
Generalized expressions for the Debye potential and the wake field potential are derived due to an axial propagation of dust grain projectiles. The dust grain projectiles are assumed to lie on sets of concentric circles propagating through the dusty plasma with a constant velocity along the z axis. Each circle carries N number of dust grain projectiles having radius r{sub l} and angular position (2{pi}m)/N. A couple of specific cases of electrostatic potential due to four and eight projectiles are studied in some detail both analytically and numerically.
Particle dynamics in a strongly-coupled dusty plasma
NASA Astrophysics Data System (ADS)
Goree, J.; Pieper, J. B.
1996-11-01
We have used video imaging to study the dynamics of 9 μ m plastic spheres suspended in low-power Krypton discharges. The spheres, which are highly charged and levitated by the electrode sheath, form a strongly-coupled system. Using a digitized series of images, we tracked individual particles and measured collective and random particle motions.footnote J. B. Pieper and J. Goree, submitted to PRL Dust acoustic waves were excited at <= 10 Hz and their dispersion relation verified. Fitting the measured and theoretical dispersion relations also give a measurement of the particle charge and the "linearized" Debye length. The temperature of random particle motion in the horizontal plane (parallel to the electrode) was measured to be 2-10 times room temperature and about 2 times the temperature in the vertical plane. It is proposed that the particles are heated by low-frequency (kHz) electrostatic plasma fluctuations. Work supported by NSF and NASA
Particle dynamics in a strongly-coupled dusty plasma
NASA Astrophysics Data System (ADS)
Quinn, R. A.; Goree, J.; Pieper, J. B.
1996-10-01
We have used video imaging to study the dynamics of 9 μ m plastic spheres in low-power Krypton discharges. The spheres, which are highly charged and levitated by the electrode sheath, form a strongly-coupled system. Using a digitized series of images, we tracked individual particles and measured collective and random particle motions.footnote Pieper and Goree, submitted to PRL Dust acoustic waves were excited at <= 10 Hz and their dispersion relation verified. The temperature of random particle motion in the horizontal plane (parallel to the electrode) was measured to be 2-10 times room temperature and about 2 times the temperature in the vertical plane. It is proposed that the particles are heated by low-frequency (kHz) electrostatic plasma fluctuations.
Diffuse spreading of inhomogeneities in the ionospheric dusty plasma
Shalimov, S. L.; Kozlovsky, A.
2015-08-15
According to results of sounding of the lower ionosphere at altitudes of about 100 km, the duration of radio reflections from sufficiently dense ionized meteor trails, which characterizes their lifetime, can reach a few tens of seconds to several tens of minutes. This is much longer than the characteristic spreading time (on the order of fractions of a second to several seconds) typical in meteor radar measurements. The presence of dust in the lower ionosphere is shown to affect the ambipolar diffusion coefficient, which determines the spreading of plasma inhomogeneities. It is found that the diffusion coefficient depends substantially on the charge and size of dust grains, which allows one to explain the results of ionospheric sounding.
Dust-acoustic shocks in strongly coupled dusty plasmas
NASA Astrophysics Data System (ADS)
Cousens, S. E.; Yaroshenko, V. V.; Sultana, S.; Hellberg, M. A.; Verheest, F.; Kourakis, I.
2014-04-01
Electrostatic dust-acoustic shock waves are investigated in a viscous, complex plasma consisting of dust particles, electrons, and ions. The system is modelled using the generalized hydrodynamic equations, with strong coupling between the dust particles being accounted for by employing the effective electrostatic temperature approach. Using a reductive perturbation method, it is demonstrated that this model predicts the existence of weakly nonlinear dust-acoustic shock waves, arising as solutions to Burgers's equation, in which the nonlinear forces are balanced by dissipative forces, in this case, associated with viscosity. The evolution and stability of dust-acoustic shocks is investigated via a series of numerical simulations, which confirms our analytical predictions on the shock characteristics.
Landau damping effects on dust-acoustic solitary waves in a dusty negative-ion plasma
Barman, Arnab; Misra, A. P. E-mail: apmisra@gmail.com
2014-07-15
The nonlinear theory of dust-acoustic waves (DAWs) with Landau damping is studied in an unmagnetized dusty negative-ion plasma in the extreme conditions when the free electrons are absent. The cold massive charged dusts are described by fluid equations, whereas the two-species of ions (positive and negative) are described by the kinetic Vlasov equations. A Korteweg-de Vries (KdV) equation with Landau damping, governing the dynamics of weakly nonlinear and weakly dispersive DAWs, is derived following Ott and Sudan [Phys. Fluids 12, 2388 (1969)]. It is shown that for some typical laboratory and space plasmas, the Landau damping (and the nonlinear) effects are more pronounced than the finite Debye length (dispersive) effects for which the KdV soliton theory is not applicable to DAWs in dusty pair-ion plasmas. The properties of the linear phase velocity, solitary wave amplitudes (in presence and absence of the Landau damping) as well as the Landau damping rate are studied with the effects of the positive ion to dust density ratio (μ{sub pd}) as well as the ratios of positive to negative ion temperatures (σ) and masses (m)
Landau damping effects on dust-acoustic solitary waves in a dusty negative-ion plasma
NASA Astrophysics Data System (ADS)
Barman, Arnab; Misra, A. P.
2014-07-01
The nonlinear theory of dust-acoustic waves (DAWs) with Landau damping is studied in an unmagnetized dusty negative-ion plasma in the extreme conditions when the free electrons are absent. The cold massive charged dusts are described by fluid equations, whereas the two-species of ions (positive and negative) are described by the kinetic Vlasov equations. A Korteweg-de Vries (KdV) equation with Landau damping, governing the dynamics of weakly nonlinear and weakly dispersive DAWs, is derived following Ott and Sudan [Phys. Fluids 12, 2388 (1969)]. It is shown that for some typical laboratory and space plasmas, the Landau damping (and the nonlinear) effects are more pronounced than the finite Debye length (dispersive) effects for which the KdV soliton theory is not applicable to DAWs in dusty pair-ion plasmas. The properties of the linear phase velocity, solitary wave amplitudes (in presence and absence of the Landau damping) as well as the Landau damping rate are studied with the effects of the positive ion to dust density ratio (μpd) as well as the ratios of positive to negative ion temperatures (σ) and masses (m).
NASA Astrophysics Data System (ADS)
Merlino, Robert
2011-10-01
In 1990, Rao, Shukla, and Yu (Planet. Space Sci. 38, 543) predicted the existence of the dust acoustic (DA) wave, a low-frequency (~ few Hz), compressional dust density wave that propagates through a dusty plasma at a phase speed ~ several cm/s. The DA wave was first observed by Chu et. al., (J. Phys. D: Appl. Phys. 27, 296, 1994) in an rf-produced dusty plasma, and by Barkan et. al., (Barkan et. al. Phys. Plasmas 2, 2161, 1995) who obtained video images of the DA wave trains using light scattering from a dust suspension confined in an anodic glow discharge plasma formed within a Q machine plasma. The dispersion relation for DAWs was measured by Thompson et. al., (Phys. Plasmas 4, 2331, 1997) in a dc glow discharge dusty plasma by modulating the discharge current at a set frequency. DAWs have been investigated by many groups both in weakly-coupled and strongly-coupled dusty plasmas (E. Thomas, Jr., Contrib. Plasma Phys. 49, 316, 2009). In most experiments where DA waves are present, the wave amplitude is relatively high, indicating that they are nonlinear. In this talk, results of our recent experiments on DAWs will be presented. The following experiments, performed in a dc glow-discharge dusty plasma will be described: (1) Observations of spontaneously excited nonlinear, cylindrical DAWs, which exhibit confluence of waves propagating at different speeds. (2) Investigations of self-steepening DAWs that develop into DA shocks with thicknesses comparable to the interparticle separation (Heinrich et. al., Phys. Rev. Lett. 103, 115001, 2009). (3) Measurements of the linear growth rates of DAWs excited in merging dust clouds. (4) The formation of stationary, stable dust density structures appearing as non-propagating DAWs (Heinrich et. al., Phys. Rev. E, in press, 2011). This work was performed in collaboration with S. H. Kim, J. R. Heinrich, and J. K. Meyer. Work supported by DOE Grant No. DE-FG01-04ER54795
Ion heating in a dusty plasma due to the dust/ion acoustic instability
Winske, D.; Gary, S.P.; Jones, M.E.
1995-08-01
The drift of plasma ions relative to charged grains in a dusty plasma can give rise to a dust/ion acoustic instability. The authors investigate the linear properties of the instability by numerically solving an appropriate linear dispersion equation and examine the nonlinear behavior through one-dimensional electrostatic particle simulations, in which the plasma and dust ions are treated as discrete particles and the electrons are modeled as a Boltzmann fluid. The instability is slightly weaker when the dust particles have a range of sizes, and corresponding range of charges and masses. It is argued that due to dust particles that comprise planetary rings, this process can contribute to ion heating and diffusion observed in the linear magnetosphere of Saturn. 14 refs., 4 figs.
NASA Astrophysics Data System (ADS)
Misra, A. P.; Chowdhury, A. Roy; Paul, S. N.
2004-09-01
Characteristic features of low frequency transverse wave propagating in a magnetised dusty plasma have been analysed considering the effect of dust-charge fluctu- ation. The distinctive behaviours of both the left circularly polarised and right circularly polarised waves have been exhibited through the analysis of linear and non-linear disper- sion relations. The phase velocity, group velocity, and group travel time for the waves have been obtained and their propagation characteristics have been shown graphically with the variations of wave frequency, dust density and amplitude of the wave. The change in non-linear wave number shift and Faraday rotation angle have also been exhibited with respect to the plasma parameters. It is observed that the effects of dust particles are significant only when the higher order contributions are considered. This may be referred to as the `dust regime' in plasma.
Nonlinear dust acoustic waves in a charge varying dusty plasma with suprathermal electrons
Tribeche, Mouloud; Bacha, Mustapha
2010-07-15
Arbitrary amplitude dust acoustic waves in a dusty plasma with a high-energy-tail electron distribution are investigated. The effects of charge variation and electron deviation from the Boltzmann distribution on the dust acoustic soliton are then considered. The dust charge variation makes the dust acoustic soliton more spiky. The dust grain surface collects less electrons as the latter evolves far away from their thermodynamic equilibrium. The dust accumulation caused by a balance of the electrostatic forces acting on the dust grains is more effective for lower values of the electron spectral index. Under certain conditions, the dust charge fluctuation may provide an alternate physical mechanism causing anomalous dissipation, the strength of which becomes important and may prevail over that of dispersion as the suprathermal character of the plasma becomes important. Our results may explain the strong spiky waveforms observed in auroral plasmas.
El-Labany, S. K.; Behery, E. E.; El-Shamy, E. F.
2013-12-15
The propagation and oblique collision of ion-acoustic (IA) solitary waves in a magnetized dusty electronegative plasma consisting of cold mobile positive ions, Boltzmann negative ions, Boltzmann electrons, and stationary positive/negative dust particles are studied. The extended Poincaré-Lighthill-Kuo perturbation method is employed to derive the Korteweg-de Vries equations and the corresponding expressions for the phase shifts after collision between two IA solitary waves. It turns out that the angle of collision, the temperature and density of negative ions, and the dust density of opposite polarity have reasonable effects on the phase shift. Clearly, the numerical results demonstrated that the IA solitary waves are delayed after the oblique collision. The current finding of this work is applicable in many plasma environments having negative ion species, such as D- and F-regions of the Earth's ionosphere and some laboratory plasma experiments.
The finite probe size effect in fluctuation measurements; application to dusty plasmas
NASA Astrophysics Data System (ADS)
Tolias, P.; Ratynskaia, S.; de Angelis, U.; Lazzaro, E.
2016-04-01
> The effect of the finite probe size in plasma fluctuation measurements is revisited for dusty plasmas, where it has been argued that dust leads to a significant low-frequency enhancement in the spectral densities of ion density fluctuations, which can constitute the physical basis of a dust diagnostic technique. Theoretical predictions for the spectral modifications are presented and the dust acoustic mode contribution is analysed. The finite probe size effect is treated within the volume average approach, which introduces geometry dependent form factors that are calculated for spherical and cylindrical probes. The volume average approach is compared with the typically employed cutoff wavenumber approximation for various dust and plasma parameters. The contribution of temperature fluctuations to the spectral density of current fluctuations is also evaluated.
On nonlinear excitation of voids in dusty plasmas
NASA Astrophysics Data System (ADS)
Nebbat, E.; Annou, R.; Bharuthram, R.
2007-09-01
The void, which is a dust-free region inside the dust cloud in the plasma, results from a balance of the electrostatic force and the ion-drag force on a dust particulate that has numerous forms, some of which are based on models whereas others are driven from first principles. To explain the generation of voids, K. Avinash, A. Bhattacharjee, and S. Hu [Phys. Rev. Lett. 90, 075001 (2003)] proposed a time-dependent nonlinear model that describes the void as a result of an instability. We augment this model by incorporating the grain drift and reintroducing the velocity convective term as well as by replacing the modeled ion-drag force by a more accurate one. The analysis is conducted in a spherical configuration. It is revealed that the void formation is a threshold phenomenon, i.e., it depends on the grain size. Furthermore, the void possesses a sharp boundary beyond which the dust density decreases and may present a corrugated aspect. For big size grains, the use of both ion-drag forces leads to voids of the same dimension, though for grains of small sizes, the Avinash force drives voids of a higher dimension. The model shows good agreement with the experiment.
On nonlinear excitation of voids in dusty plasmas
Nebbat, E.; Annou, R.; Bharuthram, R.
2007-09-15
The void, which is a dust-free region inside the dust cloud in the plasma, results from a balance of the electrostatic force and the ion-drag force on a dust particulate that has numerous forms, some of which are based on models whereas others are driven from first principles. To explain the generation of voids, K. Avinash, A. Bhattacharjee, and S. Hu [Phys. Rev. Lett. 90, 075001 (2003)] proposed a time-dependent nonlinear model that describes the void as a result of an instability. We augment this model by incorporating the grain drift and reintroducing the velocity convective term as well as by replacing the modeled ion-drag force by a more accurate one. The analysis is conducted in a spherical configuration. It is revealed that the void formation is a threshold phenomenon, i.e., it depends on the grain size. Furthermore, the void possesses a sharp boundary beyond which the dust density decreases and may present a corrugated aspect. For big size grains, the use of both ion-drag forces leads to voids of the same dimension, though for grains of small sizes, the Avinash force drives voids of a higher dimension. The model shows good agreement with the experiment.
Grain-grain interaction in stationary dusty plasma
Lampe, Martin; Joyce, Glenn
2015-02-15
We present a particle-in-cell simulation study of the steady-state interaction between two stationary dust grains in uniform stationary plasma. Both the electrostatic force and the shadowing force on the grains are calculated explicitly. The electrostatic force is always repulsive. For two grains of the same size, the electrostatic force is very nearly equal to the shielded electric field due to a single isolated grain, acting on the charge of the other grain. For two grains of unequal size, the electrostatic force on the smaller grain is smaller than the isolated-grain field, and the force on the larger grain is larger than the isolated-grain field. In all cases, the attractive shadowing force exceeds the repulsive electrostatic force when the grain separation d is greater than an equilibrium separation d{sub 0}. d{sub 0} is found to be between 6λ{sub D} and 9λ{sub D} in all cases. The binding energy is estimated to be between 19 eV and 900 eV for various cases.
2D Melting of Plasma Crystals: Equilibrium and Nonequilibrium Regimes
Nosenko, V.; Zhdanov, S. K.; Ivlev, A. V.; Knapek, C. A.; Morfill, G. E.
2009-07-03
Comprehensive experimental investigations of melting in two-dimensional complex plasmas were carried out. Different experiments were performed in steady and unsteady heating regimes. We demonstrate an Arrhenius dependence of the defect concentration on the kinetic temperature in steady-state experiments, and show the evidence of metastable quenching in unsteady experiments, where the defect concentration follows a power-law temperature scaling. In all experiments, independent indicators suggest a grain-boundary-induced melting scenario.
NASA Astrophysics Data System (ADS)
Birmingham, W. J.; Bates, E. M.; Romero-Talamás, Carlos; Rivera, W. F.
2015-11-01
For the purpose of analyzing magnetized dusty plasma at the University of Maryland Baltimore County (UMBC) Dusty Plasma Laboratory, we are designing a resistive water cooled Bitter-Type electromagnet. When completed, the magnet will be programmable to generate fields of up to 10 T for at least 10 seconds and up to several minutes. An analytic thermal design method was developed for establishing the location of elongated axial cooling passages. Comparisons with finite element analysis (FEA) data reveals that the thermal design method was capable of generating cooling channel patterns which establish manageable temperature profiles within the magnet. With our analytic method, cooling hole patterns can be generated in seconds instead of hours with FEA software. To further validate our thermal analysis as well as manufacturing techniques of our magnet design, we are now constructing a prototype electromagnet. The prototype is designed to operate continuously at 1 T with a current of 750 A, and has four diagnostic ports that can accommodate thermocouples and optical access to the water flow. A 1.25 inch diameter bore allows for axial field measurements and provides space for small scale experiments. Thermal analysis and specifics of the electromagnet design are presented.
Ion beam driven resonant ion-cyclotron instability in a magnetized dusty plasma
Prakash, Ved; Vijayshri; Sharma, Suresh C.; Gupta, Ruby
2014-03-15
Electrostatic ion cyclotron waves are excited by axial ion beam in a dusty plasma via Cerenkov and slow cyclotron interaction. The dispersion relation of the instability is derived in the presence of positively/negatively charged dust grains. The minimum beam velocity needed for the excitation is estimated for different values of relative density of negatively charged dust grains. It is shown that the minimum beam velocity needed for excitation increases as the charge density carried by dust increases. Temperature of electrons and ions, charge and mass of dust grains, external static magnetic field and finite boundary of dusty plasma significantly modify the dispersion properties of these waves and play a crucial role in the growth of resonant ion cyclotron instability. The ion cyclotron modes with phase velocity comparable to the beam velocity possess a large growth rate. The maximum value of growth rate increases with the beam density and scales as the one-third power of the beam density in Cerenkov interaction and is proportional to the square root of beam density in slow cyclotron interaction.
Development of a Split Bitter-type Magnet System for Dusty Plasma Experiments
NASA Astrophysics Data System (ADS)
Bates, Evan; Romero-Talamas, Carlos A.; Birmingham, William J.; Rivera, William F.
2014-10-01
A 10 Tesla Bitter-type magnetic system is under development at the Dusty Plasma Laboratory of the University of Maryland, Baltimore County (UMBC). We present here an optimization technique that uses differential evolution to minimize the omhic heating produced by the coils, while constraining the magnetic field in the experimental volume. The code gives us the optimal dimensions for the coil system including: coil length, turn thickness, disks radii, resistance, and total current required for a constant magnetic field. Finite element parametric optimization is then used to establish the optimal design for water cooling holes. Placement of the cooling holes will also take into consideration the magnetic forces acting on the copper alloy disks to ensure the material strength is not compromised during operation. The proposed power and cooling water delivery subsystems for the coils are also presented. Upon completion and testing of the magnet system, planned experiments include the propagation of magnetized waves in dusty plasma crystals under various boundary conditions, and viscosity in rotational shear flow, among others.
Head-on collision of dust-acoustic shock waves in strongly coupled dusty plasmas
NASA Astrophysics Data System (ADS)
EL-Shamy, E. F.; Al-Asbali, A. M.
2014-09-01
A theoretical investigation is carried out to study the propagation and the head-on collision of dust-acoustic (DA) shock waves in a strongly coupled dusty plasma consisting of negative dust fluid, Maxwellian distributed electrons and ions. Applying the extended Poincaré-Lighthill-Kuo method, a couple of Korteweg-deVries-Burgers equations for describing DA shock waves are derived. This study is a first attempt to deduce the analytical phase shifts of DA shock waves after collision. The impacts of physical parameters such as the kinematic viscosity, the unperturbed electron-to-dust density ratio, parameter determining the effect of polarization force, the ion-to-electron temperature ratio, and the effective dust temperature-to-ion temperature ratio on the structure and the collision of DA shock waves are examined. In addition, the results reveal the increase of the strength and the steepness of DA shock waves as the above mentioned parameters increase, which in turn leads to the increase of the phase shifts of DA shock waves after collision. The present model may be useful to describe the structure and the collision of DA shock waves in space and laboratory dusty plasmas.
Head-on collision of dust-acoustic shock waves in strongly coupled dusty plasmas
EL-Shamy, E. F.; Al-Asbali, A. M.
2014-09-15
A theoretical investigation is carried out to study the propagation and the head-on collision of dust-acoustic (DA) shock waves in a strongly coupled dusty plasma consisting of negative dust fluid, Maxwellian distributed electrons and ions. Applying the extended Poincaré–Lighthill–Kuo method, a couple of Korteweg–deVries–Burgers equations for describing DA shock waves are derived. This study is a first attempt to deduce the analytical phase shifts of DA shock waves after collision. The impacts of physical parameters such as the kinematic viscosity, the unperturbed electron-to-dust density ratio, parameter determining the effect of polarization force, the ion-to-electron temperature ratio, and the effective dust temperature-to-ion temperature ratio on the structure and the collision of DA shock waves are examined. In addition, the results reveal the increase of the strength and the steepness of DA shock waves as the above mentioned parameters increase, which in turn leads to the increase of the phase shifts of DA shock waves after collision. The present model may be useful to describe the structure and the collision of DA shock waves in space and laboratory dusty plasmas.
Lee, Myoung-Jae; Jung, Young-Dae
2015-02-15
The nonthermal and geometric effects on the propagation of the surface dust acoustic waves are investigated in a Lorentzian dusty plasma slab. The symmetric and anti-symmetric dispersion modes of the dust acoustic waves are obtained by the plasma dielectric function with the spectral reflection conditions the slab geometry. The variation of the nonthermal and geometric effects on the symmetric and the anti-symmetric modes of the surface plasma waves is also discussed.
Nonlinear electrostatic waves in a magnetized dusty plasma with two-temperature ions
Maharaj, S. K.; Bharuthram, R.; Pillay, S. R.; Singh, S. V.; Reddy, R. V.; Lakhina, G. S.
2008-09-07
Nonlinear low frequency electrostatic waves which arise from the coupling between two linear modes, viz., the dust-acoustic and dust-cyclotron waves, are studied in a magnetized dusty plasma comprising Boltzmann electrons, a negatively charged warm dust fluid, and two ion species of different temperatures with both species having isothermal Boltzmann distributions. The fluid equations for the dust are combined with the quasineutrality condition to obtain a single equation which governs the nonlinear evolution of the electric field for wave propagation oblique to an external magnetic field. The numerically obtained solutions for the electric field are found to have sinusoidal waveforms for small values of the initial driver electric field amplitudes and Mach numbers, whereas, spiky structures are found to be supported for larger values. Furthermore, the periods of the waveforms are found to depend on various plasma parameters such as hot and cool ion number densities and temperatures, dust drift speed and dust temperature.
Tolias, P.; Ratynskaia, S.; Angelis, U. de
2015-08-15
The soft mean spherical approximation is employed for the study of the thermodynamics of dusty plasma liquids, the latter treated as Yukawa one-component plasmas. Within this integral theory method, the only input necessary for the calculation of the reduced excess energy stems from the solution of a single non-linear algebraic equation. Consequently, thermodynamic quantities can be routinely computed without the need to determine the pair correlation function or the structure factor. The level of accuracy of the approach is quantified after an extensive comparison with numerical simulation results. The approach is solved over a million times with input spanning the whole parameter space and reliable analytic expressions are obtained for the basic thermodynamic quantities.
Stochastic dynamics of charge fluctuations in dusty plasma: A non-Markovian approach
Asgari, H.; Muniandy, S. V.; Wong, C. S.
2011-08-15
Dust particles in typical laboratory plasma become charged largely by collecting electrons and/or ions. Most of the theoretical studies in dusty plasma assume that the grain charge remains constant even though it fluctuates due to the discrete nature of the charge. The rates of ions and electrons absorption depend on the grain charge, hence its temporal evolution. Stochastic charging model based on the standard Langevin equation assumes that the underlying process is Markovian. In this work, the memory effect in dust charging dynamics is incorporated using fractional calculus formalism. The resulting fractional Langevin equation is solved to obtain the amplitude and correlation function for the dust charge fluctuation. It is shown that the effects of ion-neutral collisions can be interpreted in phenomenological sense through the nonlocal fractional order derivative.
Nonuniform charging effects on ion drag force in drifting dusty plasmas
Chang, Dong-Man; Chang, Won-Seok; Jung, Young-Dae
2006-03-01
The nonuniform polarization charging effects on the ion drag force are investigated in drifting dusty plasmas. The ion drag force due to the ion-dust grain interaction is obtained as a function of the dust charge, ion charge, plasma temperature, Mach number, Debye length, and collision energy. The result shows that the nonuniform charging effects enhance the momentum transfer cross section as well as the ion drag force. It is found that the momentum transfer cross section and the ion drag force including nonuniform polarization charging effects increase with increasing the Mach number and also the ion drag force increases with increasing the temperature. In addition, it is found that the ion drag force is slightly decreasing with an increase of the Debye length.
Dust ion-acoustic solitary waves in a dusty plasma with nonextensive electrons
NASA Astrophysics Data System (ADS)
Bacha, Mustapha; Tribeche, Mouloud; Shukla, Padma Kant
2012-05-01
The dust-modified ion-acoustic waves of Shukla and Silin are revisited within the theoretical framework of the Tsallis statistical mechanics. Nonextensivity may originate from correlation or long-range plasma interactions. Interestingly, we find that owing to electron nonextensivity, dust ion-acoustic (DIA) solitary waves may exhibit either compression or rarefaction. Our analysis is then extended to include self-consistent dust charge fluctuation. In this connection, the correct nonextensive electron charging current is rederived. The Korteweg-de Vries equation, as well as the Korteweg-de Vries-Burgers equation, is obtained, making use of the reductive perturbation method. The DIA waves are then analyzed for parameters corresponding to space dusty plasma situations.
Dust kinetic Alfvén solitary and rogue waves in a superthermal dusty plasma
Saini, N. S. Singh, Manpreet; Bains, A. S.
2015-11-15
Dust kinetic Alfvén solitary waves (DKASWs) have been examined in a low-β dusty plasma comprising of negatively charged dust grains, superthermal electrons, and ions. A nonlinear Korteweg-de Vries (KdV) equation has been derived using the reductive perturbation method. The combined effects of superthermality of charged particles (via κ), plasma β, obliqueness of propagation (θ), and dust concentration (via f) on the shape and size of the DKASWs have been examined. Only negative potential (rarefactive) structures are observed. Further, characteristics of dust kinetic Alfvén rogue waves (DKARWs), by deriving the non-linear Schrödinger equation (NLSE) from the KdV equation, are studied. Rational solutions of NLSE show that rogue wave envelopes are supported by this plasma model. It is observed that the influence of various plasma parameters (superthermality, plasma β, obliqueness, and dust concentration) on the characteristics of the DKARWs is very significant. This fundamental study may be helpful in understanding the formation of coherent nonlinear structures in space and astrophysical plasma environments where superthermal particles are present.
Dust kinetic Alfvén solitary and rogue waves in a superthermal dusty plasma
NASA Astrophysics Data System (ADS)
Saini, N. S.; Singh, Manpreet; Bains, A. S.
2015-11-01
Dust kinetic Alfvén solitary waves (DKASWs) have been examined in a low-β dusty plasma comprising of negatively charged dust grains, superthermal electrons, and ions. A nonlinear Korteweg-de Vries (KdV) equation has been derived using the reductive perturbation method. The combined effects of superthermality of charged particles (via κ), plasma β, obliqueness of propagation (θ), and dust concentration (via f) on the shape and size of the DKASWs have been examined. Only negative potential (rarefactive) structures are observed. Further, characteristics of dust kinetic Alfvén rogue waves (DKARWs), by deriving the non-linear Schrödinger equation (NLSE) from the KdV equation, are studied. Rational solutions of NLSE show that rogue wave envelopes are supported by this plasma model. It is observed that the influence of various plasma parameters (superthermality, plasma β, obliqueness, and dust concentration) on the characteristics of the DKARWs is very significant. This fundamental study may be helpful in understanding the formation of coherent nonlinear structures in space and astrophysical plasma environments where superthermal particles are present.
Transmission characteristics of microwave in a glow-discharge dusty plasma
NASA Astrophysics Data System (ADS)
Jia, Jieshu; Yuan, Chengxun; Gao, Ruilin; Liu, Sha; Yue, Feng; Wang, Ying; Zhou, Zhong-Xiang; Wu, Jian; Li, Hui
2016-07-01
In this study, the propagation characteristics of electromagnetic wave in a glow discharge plasma with dust particles are experimentally investigated. A helium alternating current glow discharge plasmas have been successfully generated. Measurements of the plasma parameters using Langmuir probes, in the absence of dust particles, provide plasma densities (ne) of 1017 m-3 and electron temperatures (Te) ranging from 2 to 4 eV. Dusty plasmas are made by adding 30 nm radius aluminum oxide (Al2O3) particles into the helium plasma. The density of the dust particle (nd) in the device is about 1011-1012 m-3. The propagation characteristics of electromagnetic waves are determined by a vector network analyzer with 4-6 GHz antennas. An apparent attenuation by the dust is observed, and the measured attenuation data are approximately in accordance with the theoretical calculations. The effects of gas pressure and input power on the propagation are also investigated. Results show that the transmission attenuation increases with the gas pressure and input power, the charged dust particles play a significant role in the microwave attenuation.
A Study of Ion Drag for Ground and Microgravity Dusty Plasma Experiments
NASA Astrophysics Data System (ADS)
Hall, Taylor; Thomas, Edward
2015-11-01
This presentation presents the results of a recent study of the interaction between charged dust particles and plasma ions through the ion drag force 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 competition between the ion drag and electric forces on the particles. These forces are calculated for a range of pressures using detailed measurements of the plasma parameters carried out by a single Langmuir probe. The analysis of these measurements suggests that a change in the relative magnitude of the Coulomb collision ion drag compared to the electric force is a probable explanation for the observed reversal of direction of motion as the neutral gas pressure is increased. The application of these results to microgravity studies of dusty plasmas will be discussed. Support provided by NASA-JPL (JPL-RSA 1471384).
Rouhani, M. R.; Akbarian, A.; Mohammadi, Z.
2013-08-15
The behavior of quantum dust ion acoustic soliton and shocks in a plasma including inertialess quantum electrons and positrons, classical cold ions, and stationary negative dust grains are studied, using arbitrary amplitude approach. The effect of dissipation due to viscosity of ions is taken into account. The numerical analysis of Sagdeev potential for small value of quantum diffraction parameter (H) shows that for chosen plasma, only compressive solitons can exist and the existence domain of this type of solitons is decreased by increasing dust density (d). Additionally, the possibility of propagation of both subsonic and supersonic compressive solitons is investigated. It is shown that there is a critical dust density above which only supersonic solitons are observed. Moreover, increasing d leads to a reduction in the existence domain of compressive solitons and the possibility of propagation of rarefactive soliton is provided. So, rarefactive solitons are observed only due to the presence of dust particles in this model quantum plasma. Furthermore, numerical solution of governed equations for arbitrary amplitude shock waves has been investigated. It is shown that only compressive large amplitude shocks can propagate. Finally, the effects of plasma parameters on these structures are investigated. This research will be helpful in understanding the properties of dense astrophysical (i.e., white dwarfs and neutron stars) and laboratory dusty plasmas.
Shock waves with higher order effects in an electron depleted dusty Plasma
NASA Astrophysics Data System (ADS)
Ghai, Yashika; Singh Saini, Nareshpal; Singh, Manpreet
2016-07-01
Shock waves are characterized as a sudden change in properties of the medium that propagate faster than the speed of sound. A plasma system in which dissipation is dominant over dispersion of the medium, the balance between dissipation and nonlinearity leads to the formation of shock structures. A number of observations and in-situ measurements have confirmed the presence of excess superthermal populations in astrophysical and space plasmas. In fact, two temperature superthermal ion populations have been observed by Geotail spacecraft in earth's magnetotail. Moreover, charging of dust by accumulation of electrons in plasma leads to electron depleted plasma. In present investigation, shocks in an electron depleted dusty plasma with two temperature superthermal ions have been studied by using Burger's equation. Further, to incorporate higher order nonlinear effects, we have derived modified Burger's equation and studied its shock solution. The effects of various physical parameters such as superthermality of ions, kinematic viscosity and dust concentration have been observed on properties of shock structures. The results of present investigation may be useful in understanding the nonlinear structures formed in earth's atmosphere where dust and two temperature superthermal ions are observed.
Haloperidol plasma concentration in Japanese psychiatric subjects with gene duplication of CYP2D6
Ohnuma, Tohru; Shibata, Nobuto; Matsubara, Yoichiro; Arai, Heii
2003-01-01
Aims The cytochrome P-450 2D6 (CYP2D6) gene duplication/multiduplication producing an increase in enzyme activity, and the common Japanese mutation, CYP2D6*10A producing a decrease of enzyme activity were screened in a large number of Japanese psychiatric subjects (n = 111) in order to investigate whether these mutated alleles affected the plasma concentration of haloperidol. Methods Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was performed to identify the CYP2D6*10A and CYP2D6*2 genotypes in subjects who had been taking haloperidol. For the screening of duplicated active CYP2D6 gene, allele-specific long PCR was performed. Plasma concentration of haloperidol was measured by the enzyme immunoassay, and expressed as ‘plasma concentration dose ratio’ to normalize individual differences. Results The plasma concentration–dose ratio showed large interindividual differences of approximately 18-fold. PCR-RFLP methods revealed that 29 (26.1%), 10 (9.0%), 39 (35.1%), 0 (0%), seven (6.3%) and 26 (23.4%) cases possessed the CYP2D6 genotypes *1/*1, *1/*2, *1/*10A, *2/*2, *2/*10A and *10 A/*10A, respectively. Six cases (5.4%) had duplicated CYP2D6 genes. There were no significant differences of plasma concentration–dose ratio between the groups classified by CYP2D6*10A and *2 genotypes (Kruskal–Wallis test; P = 0.37), even in those cases whose daily doses were lower than 20 mg (n = 90, P = 0.91). Subjects having duplicated genes (n = 6) did not show significant differences of plasma concentration–dose ratio by comparison with subjects who had no duplicated genes (Mann–Whitney U-test; P = 0.80). Conclusions Gene duplication, and the common Japanese mutation CYP2D6*10A on CYP2D6 gene are not likely to be the main modulatory factors of plasma concentration of haloperidol in Japanese psychiatric subjects. PMID:12919180
Statistics of particle transport in a two-dimensional dusty plasma cluster
Ratynskaia, S.; Knapek, C.; Rypdal, K.; Khrapak, S.; Morfill, G.
2005-02-01
Statistical analysis is performed on long time series of dust particle trajectories in a two-dimensional dusty plasma cluster. Particle transport is found to be superdiffusive on all time scales until the range of particle displacements approaches the size of the cluster. Analysis of probability distribution functions and rescaled range analysis of the position increments show that the signal is non-Gaussian self-similar with Hurst exponent H=0.6, indicating that the superdiffusion is caused by long-range dependencies in the system. Investigation of temporal and spatial characteristics of persistent particle slips demonstrates that they are associated with collective events present on all time scales and responsible for the non-Gaussianity and long-memory effects.
Cooperative microexcitations in 2+1D chain-bundle dusty plasma liquids
Io, C.-W.; Chan, C.-L.; Lin I
2010-05-15
Through direct visualization at the discrete level, the microexcitations in cold 2+1D dusty plasma liquids formed by negatively charged dusts suspended in low pressure gaseous discharges were experimentally investigated, in which the downward ion flow wake field induces strong vertical coupling and chain bundle structure. It is found that the horizontal structure and motion are similar to those of the two-dimensional liquid. Different types of basic cooperative chain excitations: straight vertical chains with small amplitude jittering, chain tilting-restraightening, bundle twisting-restraightening, and chain breaking-reconnection, are observed. The region with good (poor) horizontal structural order prefers the straight (tilted or broken) chains with little (large) titling and tilting rate.
Formation and evolution of vortices in a collisional strongly coupled dusty plasma
NASA Astrophysics Data System (ADS)
Jana, Sayanee; Banerjee, Debabrata; Chakrabarti, Nikhil
2016-07-01
Formation and evolution of vortices are studied in a collisional strongly coupled dusty plasma in the framework of a Generalized Hydrodynamic model (GH). Here we mainly present the nonlinear dynamical response of this strongly coupled system in presence of dust-neutral collisional drag. It is shown that the interplay between the nonlinear elastic stress and the dust-neutral collisional drag results in the generation of non-propagating monopole vortex for some duration before it starts to propagate like transverse shear wave. It is also found that the interaction between two unshielded monopole vortices having both same (co-rotating) and opposite (counter rotating) rotations result in the formation of two propagating dipole vortices of equal and unequal strength respectively. These results will provide some new understanding on the transport properties in such a strongly coupled system. The numerical simulation is carried out using a de-aliased doubly periodic pseudo-spectral code with Runge-Kutta-Gill time integrator.
Observation of dust acoustic shock wave in a strongly coupled dusty plasma
NASA Astrophysics Data System (ADS)
Sharma, Sumita K.; Boruah, A.; Nakamura, Y.; Bailung, H.
2016-05-01
Dust acoustic shock wave is observed in a strongly coupled laboratory dusty plasma. A supersonic flow of charged microparticles is allowed to perturb a stationary dust fluid to excite dust acoustic shock wave. The evolution process beginning with steepening of initial wave front and then formation of a stable shock structure is similar to the numerical results of the Korteweg-de Vries-Burgers equation. The measured Mach number of the observed shock wave agrees with the theoretical results. Reduction of shock amplitude at large distances is also observed due to the dust neutral collision and viscosity effects. The dispersion relation and the spatial damping of a linear dust acoustic wave are also measured and compared with the relevant theory.
Nonlinear features of ion acoustic shock waves in dissipative magnetized dusty plasma
Sahu, Biswajit; Sinha, Anjana; Roychoudhury, Rajkumar
2014-10-15
The nonlinear propagation of small as well as arbitrary amplitude shocks is investigated in a magnetized dusty plasma consisting of inertia-less Boltzmann distributed electrons, inertial viscous cold ions, and stationary dust grains without dust-charge fluctuations. The effects of dissipation due to viscosity of ions and external magnetic field, on the properties of ion acoustic shock structure, are investigated. It is found that for small amplitude waves, the Korteweg-de Vries-Burgers (KdVB) equation, derived using Reductive Perturbation Method, gives a qualitative behaviour of the transition from oscillatory wave to shock structure. The exact numerical solution for arbitrary amplitude wave differs somehow in the details from the results obtained from KdVB equation. However, the qualitative nature of the two solutions is similar in the sense that a gradual transition from KdV oscillation to shock structure is observed with the increase of the dissipative parameter.
Sheared Flow Driven Drift Instability and Vortices in Dusty Plasmas with Opposite Polarity
NASA Astrophysics Data System (ADS)
Mushtaq, A.; Shah, AttaUllah; Ikram, M.; Clark, R. E. H.
2016-02-01
Low-frequency electrostatic drift waves are studied in an inhomogeneous dust magnetoplasma containing dust with components of opposite polarity. The drift waves are driven by the magnetic-field-aligned (parallel) sheared flows in the presence of electrons and ions. Due to sheared flow in the linear regime, the electrostatic dust drift waves become unstable. The conditions of mode instability, with the effects of dust streaming and opposite polarity, are studied. These are excited modes which gain large amplitudes and exhibit interactions among themselves. The interaction is governed by the Hasegawa-Mima (HM) nonlinear equation with vector nonlinearity. The stationary solutions of the HM equation in the form of a vortex chain and a dipolar vortex, including effects of dust polarity and electron (ion) temperatures, are studied. The relevance of the present work to space and laboratory four component dusty plasmas is noted.
NASA Astrophysics Data System (ADS)
Seadawy, Aly R.
2015-12-01
The propagation of dust-ion-acoustic waves with high-energy electrons and positrons in three-dimensional is considered. The Zakharov-Kuznetsov-Burgers (ZKB) equations for the dust-ion-acoustic waves in dusty plasmas is obtained. The conservations laws and integrals of motion for the ZKB equation are deduced. In the present study, by applying the modified direct algebraic method, we found the electric field potential, electric field and quantum statistical pressure in form water wave solutions for three-dimensional ZKB equation. The solutions for the ZKB equation are obtained precisely and efficiency of the method can be demonstrated. The stability of the obtained solutions and the movement role of the waves by making the graphs of the exact solutions are discussed and analyzed.
Head-on-collision of modulated dust acoustic waves in strongly coupled dusty plasma
El-Labany, S. K.; El-Depsy, A.; Zedan, N. A.; El-Taibany, W. F.; El-Shamy, E. F.
2012-10-15
The derivative expansion perturbation method is applied to a strongly coupled dusty plasma system consisting of negatively charged dust grains, electrons, and ions. The basic equations are reduced to a nonlinear Schroedinger type equation appropriate for describing the modulated dust acoustic (DA) waves. We have examined the modulation (in) stability and the dependence of the system physical parameters (angular frequency and group velocity) on the polarization force variation. Finally, the extended Poincare-Lighthill-Kuo technique is employed to investigate the head-on collision (HoC) between two DA dark solitons. The analytical phase shifts and the trajectories of these dark solitons after the collision are derived. The numerical illustrations show that the polarization effect has strong influence on the nature of the phase shifts and the trajectories of the two DA dark solitons after collision.
Force measurements in dusty plasmas under microgravity by means of laser manipulation
Wolter, Matthias; Melzer, Andre; Arp, Oliver; Klindworth, Markus; Piel, Alexander
2007-12-15
Experiments in a dusty plasma under the microgravity conditions of parabolic flights are presented. Under microgravity, extended dust structures and a central dust-free region ('void') are formed. Here, the forces and the force balance at the void boundary are studied by means of laser manipulation of the dust particles: A focused laser beam is moved in a controlled way to drive particles in the extended dust cloud and at the void boundary. From the observed particle motion, the forces on the particles in the dust cloud and at the void boundary are derived. Together with Langmuir probe measurements, a quantitative description of the force balance has been achieved. Special attention has been paid to the ion drag force, which is crucial in understanding the void formation. The results are compared to prevalent ion drag models.
Tribeche, Mouloud; Boumezoued, Ghania
2008-05-15
The effect of nonthermal electrons with excess of fast energetic electrons on large amplitude electrostatic solitary waves is investigated in a charge varying dusty plasma. The correct nonthermal electron charging is investigated based on the orbit-motion-limited approach. It is found that the nonlinear localized potential structure shrinks when the electrons deviate from isothermality. The dust particles are locally expelled and pushed out the region of the soliton localization as the electrons evolve far away from their thermodynamic equilibrium. Under certain conditions, the dust charge fluctuation may provide an alternate physical mechanism causing anomalous dissipation, the strength of which becomes important and may prevail over that of dispersion as the value of the electron nonthermal parameter {alpha} increases.
Collisionless damping of dust-acoustic waves in a charge varying dusty plasma with nonextensive ions
Amour, Rabia; Tribeche, Mouloud
2014-12-15
The charge variation induced nonlinear dust-acoustic wave damping in a charge varying dusty plasma with nonextensive ions is considered. It is shown that the collisionless damping due to dust charge fluctuation causes the nonlinear dust acoustic wave propagation to be described by a damped Korteweg-de Vries (dK-dV) equation the coefficients of which depend sensitively on the nonextensive parameter q. The damping term, solely due to the dust charge variation, is affected by the ion nonextensivity. For the sake of completeness, the possible effects of nonextensivity and collisionless damping on weakly nonlinear wave packets described by the dK-dV equation are succinctly outlined by deriving a nonlinear Schrödinger-like equation with a complex nonlinear coefficient.
Dust acoustic dromions in a magnetized dusty plasma with superthermal electrons and ions
NASA Astrophysics Data System (ADS)
Saini, N. S.; Ghai, Yashika; Kohli, Ripin
2016-06-01
An investigation of dust acoustic (DA) dromions in a magnetized dusty plasma consisting of inertial dust fluid, kappa-type distributed electrons, and ions is presented. Using reductive perturbation technique, we have derived coupled nonlinear evolution equations of (2 + 1) dimensions (called Davey-Stewartson (DS-I) equations). Hirota bilinear method has been employed to derive the analytical solution of DS-I equations. The solutions of such equations are exponentially localized and are called dromions. The combined effects of various physical parameters such as superthermality of charged particles, strength of magnetic field, and dust concentration have been studied on the existence regions and propagation properties of DA dromions in context with observations of POLAR satellite in the presence of superthermal particles in polar cap boundary layer region of Earth's atmosphere.
Liu, Bin; Goree, J.
2014-06-15
The diffusion of projectiles drifting through a target of strongly coupled dusty plasma is investigated in a simulation. A projectile's drift is driven by a constant force F. We characterize the random walk of the projectiles in the direction perpendicular to their drift. The perpendicular diffusion coefficient D{sub p⊥} is obtained from the simulation data. The force dependence of D{sub p⊥} is found to be a power law in a high force regime, but a constant at low forces. A mean kinetic energy W{sub p} for perpendicular motion is also obtained. The diffusion coefficient is found to increase with W{sub p} with a linear trend at higher energies, but an exponential trend at lower energies.
Collisionless damping of dust-acoustic waves in a charge varying dusty plasma with nonextensive ions
NASA Astrophysics Data System (ADS)
Amour, Rabia; Tribeche, Mouloud
2014-12-01
The charge variation induced nonlinear dust-acoustic wave damping in a charge varying dusty plasma with nonextensive ions is considered. It is shown that the collisionless damping due to dust charge fluctuation causes the nonlinear dust acoustic wave propagation to be described by a damped Korteweg-de Vries (dK-dV) equation the coefficients of which depend sensitively on the nonextensive parameter q. The damping term, solely due to the dust charge variation, is affected by the ion nonextensivity. For the sake of completeness, the possible effects of nonextensivity and collisionless damping on weakly nonlinear wave packets described by the dK-dV equation are succinctly outlined by deriving a nonlinear Schrödinger-like equation with a complex nonlinear coefficient.
Nonlinear features of ion acoustic shock waves in dissipative magnetized dusty plasma
NASA Astrophysics Data System (ADS)
Sahu, Biswajit; Sinha, Anjana; Roychoudhury, Rajkumar
2014-10-01
The nonlinear propagation of small as well as arbitrary amplitude shocks is investigated in a magnetized dusty plasma consisting of inertia-less Boltzmann distributed electrons, inertial viscous cold ions, and stationary dust grains without dust-charge fluctuations. The effects of dissipation due to viscosity of ions and external magnetic field, on the properties of ion acoustic shock structure, are investigated. It is found that for small amplitude waves, the Korteweg-de Vries-Burgers (KdVB) equation, derived using Reductive Perturbation Method, gives a qualitative behaviour of the transition from oscillatory wave to shock structure. The exact numerical solution for arbitrary amplitude wave differs somehow in the details from the results obtained from KdVB equation. However, the qualitative nature of the two solutions is similar in the sense that a gradual transition from KdV oscillation to shock structure is observed with the increase of the dissipative parameter.
Nonplanar dust acoustic solitary waves in a strongly coupled dusty plasma with superthermal ions
El-Labany, S. K. Zedan, N. A.; El-Taibany, W. F. E-mail: eltaibany@du.edu.eg; El-Shamy, E. F.
2014-12-15
The nonplanar amplitude modulation of dust acoustic (DA) envelope solitary waves in a strongly coupled dusty plasma (SCDP) has been investigated. By using a reductive perturbation technique, a modified nonlinear Schrödinger equation (NLSE) including the effects of geometry, polarization, and ion superthermality is derived. The modulational instability (MI) of the nonlinear DA wave envelopes is investigated in both planar and nonplanar geometries. There are two stable regions for the DA wave propagation strongly affected by polarization and ion superthermality. Moreover, it is found that the nonlinear DA waves in spherical geometry are the more structurally stable. The larger growth rate of the nonlinear DA MI is observed in the cylindrical geometry. The salient characteristics of the MI in the nonplanar geometries cannot be found in the planar one. The DA wave propagation and the NLSE solutions are investigated both analytically and numerically.
Energy loss for the assemblies of charged projectiles in a dusty plasma
Ali, S.; Murtaza, G.; Nasim, M.H.
2005-07-15
Expressions for the electrostatic potential and the energy loss are derived for a variety of arrays of dust grain projectiles, arranged at different orientations and separations and moving with a constant velocity along the z axis in an unmagnetized collisionless dusty plasma, using linear dielectric theory. By employing the dielectric constant of dust acoustic wave, the Debye and wake potentials are calculated for the projectiles. It is found that a projectile moving with high speed forms a negative wake behind and a shock in front of it. Further, for particular values of interspacing, the three different assemblies exhibit almost similar behavior of the energy loss and thus permit the possibility of all of them to move in unison to establish a dynamical equilibrium in a hexagonal geometry.
Kelvin-Helmholtz instability in a strongly coupled dusty plasma medium
Tiwari, Sanat Kumar; Das, Amita; Patel, Bhavesh G.; Angom, Dilip; Kaw, Predhiman
2012-07-15
The Kelvin-Helmholtz (KH) instability in the context of strongly coupled dusty plasma medium has been investigated. In particular, the role of transverse shear and the compressional acoustic modes in both the linear and nonlinear regimes of the KH instability has been studied. It is observed that in addition to the conventional nonlocal KH instability, there exists a local instability in the strong coupling case. The interplay of the KH mode with this local instability shows up in the simulations as an interesting phenomenon of recurrence in the nonlinear regime. Thus, a cyclic KH instability process is observed to occur. These cyclic events are associated with bursts of activity in terms of transverse and compressional wave generation in the medium.
El-Taibany, W. F. E-mail: eltaibany@hotmail.com; Selim, M. M.; Al-Abbasy, O. M.; El-Bedwehy, N. A.
2014-07-15
The propagation of both linear and nonlinear dust acoustic waves (DAWs) in an inhomogeneous magnetized collisional and warm dusty plasma (DP) consisting of Boltzmann ions, nonextensive electrons, and inertial dust particles is investigated. The number density gradients of all DP components besides the inhomogeneities of electrostatic potential and the initial dust fluid velocity are taken into account. The linear dispersion relation and a nonlinear modified Zakharov-Kusnetsov (MZK) equation governing the propagation of the three-dimensional DAWs are derived. The analytical solution of the MZK reveals the creation of both compressive and rarefactive DAW solitons in the proposed model. It is found that the inhomogeneity dimension parameter and the electron nonextensive parameter affect significantly the nonlinear DAW's amplitude, width, and Mach number. The relations of our findings with some astrophysical situations have been given.
Final Scientific/Technical Report for "Strongly-Coupled Dusty Plasmas"
John Goree
2010-08-14
The subject of the project is the basic-plasma physics topic of strongly-coupled plasmas, as studied experimentally using dusty plasmas. This topic is highly interdisciplinary, with significant overlap with astrophysics, space physics, and condensed matter physics. Among the successes of this project during the most recent four-year period are the 23 papers were produced for peer-reviewed scientific journals. These papers mostly report experiments, as well as some numerical simulations. Coauthors of the papers include collaborators in Germany, Hungary, and Russia, as well as the U.S. Research topics included traditional plasma physics themes such as transport, waves, instabilities, and experimental diagnostics. They also included interdisciplinary topics of melting (condensed matter physics) and rarefied gas dynamics (fluid mechanics). All of the research topics were chosen to have a high impact. Our success in achieving a high impact is demonstrated by the seven papers published in Physical Review Letters over a four-year period, and a significant number of invited talks. The project included a broader-impact element that included not only training of graduate students and public dissemination of research results, but also an outreach program. The outreach Included presentations motivated by the sound-wave experiments in this project for the 'Family Science Adventures' (for children and parents of Iowa City area) and hands-on experiments at a K12 school (3rd and 4th grades in 2007, and 5th and 6th grades in 2008).
Dust-ion-acoustic shock waves in nonextensive dusty multi-ion plasmas
NASA Astrophysics Data System (ADS)
Ema, S. A.; Ferdousi, M.; Sultana, S.; Mamun, A. A.
2015-03-01
A theoretical and numerical analysis of dust-ion-acoustic (DIA) shock waves has been carried out in an unmagnetized dusty multi-ion plasma containing nonextensive electrons, inertial negatively charged heavy ions, positively charged Maxwellian light ions, and negatively charged stationary dusts. The normal mode analysis is used to examine the linear properties of DIA waves (DIAWs). The reductive perturbation technique is employed in order to derive the nonlinear time evolution Burgers type equation (which describes the shock waves properties). The basic features ( viz. polarity, amplitude, width, etc.) of the DIA shock waves are investigated. It is found that the basic features of DIA shock waves are significantly modified depending on the intrinsic parameters ( viz. electron nonextensivity, heavy ions kinematic viscosity, heavy-to-light ion number density ratio, electron-to-light ion temperature ratio, etc.) of the considered plasma system. Both polarities (positive and negative potential) are also found to exist in the plasma under consideration in this paper. The findings of this investigation may be used in understanding the wave propagation in laboratory and space plasmas.
Compressive and rarefactive dust-ion-acoustic Gardner solitons in a multi-component dusty plasma
Ema, S. A.; Ferdousi, M.; Mamun, A. A.
2015-04-15
The linear and nonlinear propagations of dust-ion-acoustic solitary waves (DIASWs) in a collisionless four-component unmagnetized dusty plasma system containing nonextensive electrons, inertial negative ions, Maxwellian positive ions, and negatively charged static dust grains have been investigated theoretically. The linear properties are analyzed by using the normal mode analysis and the reductive perturbation method is used to derive the nonlinear equations, namely, the Korteweg-de Vries (K-dV), the modified K-dV (mK-dV), and the Gardner equations. The basic features (viz., polarity, amplitude, width, etc.) of Gardner solitons (GS) are found to exist beyond the K-dV limit and these dust-ion-acoustic GS are qualitatively different from the K-dV and mK-dV solitons. It is observed that the basic features of DIASWs are affected by various plasma parameters (viz., electron nonextensivity, negative-to-positive ion number density ratio, electron-to-positive ion number density ratio, electron-to-positive ion temperature ratio, etc.) of the considered plasma system. The findings of our results obtained from this theoretical investigation may be useful in understanding the nonlinear structures and the characteristics of DIASWs propagating in both space and laboratory plasmas.
NASA Astrophysics Data System (ADS)
Bernhardt, P. A.; Siefring, C. L.; Gatling, G.; Briczinski, S. J., Jr.; Vierinen, J.; Bhatt, A.; Holzworth, R. H., II; McCarthy, M.; Gustavsson, B.; La Hoz, C.; Latteck, R.
2015-12-01
A sounding rocket launched from Andoya, Norway in September 2015 carried 37 rocket motors and a multi-instrument daughter payload into the ionosphere to study the generation of plasma wave electric fields and ionospheric density disturbances by the high-speed injection of dust particles. The primary purpose of the CARE II mission is to validate the dress-particle theory of enhanced incoherent scatter from a dusty plasma and to validate models of plasma instabilities driven by high-speed charged particles. The CARE II chemical payload produces 66 kg of micron-sized dust particles composed of aluminium oxide. In addition to the dust, simple molecular combustion products such as N2, H2, CO2, CO, H20 and NO will be injected into the bottomside of the F-layer. Charging of the dust and ion charge exchange with the molecules yields plasma particles moving at hypersonic velocities. Streaming instabilities and shear electric fields causes plasma turbulence that can be detected using ground radars and in situ plasma instruments. The instrument payload was separated from the chemical release payload soon after launch to measure electric field vectors, electron and ion densities, and integrated electron densities from the rocket to the ground. The chemical release of high speed dust was directed upward on the downleg of the rocket trajectory to intersect the F-Layer. The instrument section was about 600 meters from the dust injection module at the release time. Ground HF and UHF radars were operated to detected scatter and refraction by the modified ionosphere. Optical instruments from airborne and ground observatories were used to map the dispersal of the dust using scattered sunlight. The plasma interactions are being simulated with both fluid and particle-in-cell (PIC) codes. CARE II is a follow-on to the CARE I rocket experiment conducted from Wallops Island Virginia in September 2009.
Catapano, F. Zimbardo, G.; Artemyev, A. V. Vasko, I. Y.
2015-09-15
We develop current sheet models which allow to regulate the level of plasma temperature and density inhomogeneities across the sheet. These models generalize the classical Harris model via including two current-carrying plasma populations with different temperature and the background plasma not contributing to the current density. The parameters of these plasma populations allow regulating contributions of plasma density and temperature to the pressure balance. A brief comparison with spacecraft observations demonstrates the model applicability for describing the Earth magnetotail current sheet. We also develop a two dimensional (2D) generalization of the proposed model. The interesting effect found for 2D models is the nonmonotonous profile (along the current sheet) of the magnetic field component perpendicular to the current sheet. Possible applications of the model are discussed.
Maharaj, S. K.; Bharuthram, R.; Pillay, S. R.; Singh, S. V.; Reddy, R. V.; Lakhina, G. S.
2008-09-07
In view of the observations of parallel (to Earth's magnetic field) spiky electric field structures by the FAST satellite, a theoretical study is conducted using a dusty plasma model comprising Boltzmann distributed hot and cool ions, Boltzmann electrons and a negatively charged cold dust fluid to investigate the existence of similar low frequency nonlinear electrostatic waves in a dusty plasma which could have a similar appearance as the observed waveforms. Charge separation effects are incorporated into our model by the inclusion of Poisson's equation as opposed to assuming quasineutrality. The system of nonlinear equations is then numerically solved. The resulting electric field structure is examined as a function of various plasma parameters such as Mach number, driving electric field amplitude, bulk dust drift speed, particle densities and particle temperatures.
2-D PSD Diagnostic System for the Pellet Trajectory in LHD Plasmas
NASA Astrophysics Data System (ADS)
Hoshino, Mitsuyasu; Sakamoto, Ryuichi; Yamada, Hiroshi; Itoh, Yasuhiko; Kumagai, Kohki; Kumazawa, Ryuhei; Watari, Tetsuo; LHD Experimental Group
Ablation of a solid hydrogen pellet in hot plasmas of Large Helical Device (LHD) has been studied. A position sensitive detector (PSD) diagnostics has been newly installed to measure the trajectory of ablating pellets. 2-D diagnostics enables the measurement with high time (1 MHz) and spatial resolutions (80 μm). A 3-D pellet trajectory can be described by a combination of 2-D images and information of initial pellet direction and velocity. A deflection of the pellet trajectory in the neutral beam injection (NBI) heated plasmas of LHD has been observed. Means of improving the measurement accuracy of this system are also discussed.
Obliquely propagating cnoidal waves in a magnetized dusty plasma with variable dust charge
Yadav, L. L.; Sayal, V. K.
2009-11-15
We have studied obliquely propagating dust-acoustic nonlinear periodic waves, namely, dust-acoustic cnoidal waves, in a magnetized dusty plasma consisting of electrons, ions, and dust grains with variable dust charge. Using reductive perturbation method and appropriate boundary conditions for nonlinear periodic waves, we have derived Korteweg-de Vries (KdV) equation for the plasma. It is found that the contribution to the dispersion due to the deviation from plasma approximation is dominant for small angles of obliqueness, while for large angles of obliqueness, the dispersion due to magnetic force becomes important. The cnoidal wave solution of the KdV equation is obtained. It is found that the frequency of the cnoidal wave depends on its amplitude. The effects of the magnetic field, the angle of obliqueness, the density of electrons, the dust-charge variation and the ion-temperature on the characteristics of the dust-acoustic cnoidal wave are also discussed. It is found that in the limiting case the cnoidal wave solution reduces to dust-acoustic soliton solution.
Dust-ion-acoustic Gardner solitons in a dusty plasma with bi-Maxwellian electrons
Masud, M. M.; Asaduzzaman, M.; Mamun, A. A.
2012-10-15
The nonlinear propagation of dust-ion-acoustic (DIA) waves in a dusty plasma with bi-Maxwellian electrons, namely, lower and higher temperature electrons (composed of negatively charged stationary dust, inertial ions, and non-inertial two-temperature-electrons) is investigated by deriving the Gardner equation using the reductive perturbation technique. The basic features (amplitude, width, etc.) of the hump (positive potential) and dip (negative potential) shaped DIA solitons (Gardner solitons, i.e., GSs) are found to exist beyond the Korteweg-de Vries (K-dV) limit. These DIA-GSs are qualitatively different from the K-dV and modified K-dV solitons. It is also shown that depending on the parameter {sigma} (where {sigma}=T{sub e1}/T{sub e2}, T{sub e1} and T{sub e2} being the temperatures of two distinct electrons and T{sub e1} Much-Less-Than T{sub e2}), the DIA-GSs exhibit hump and dip shape solitary structures. The implications of our results in understanding the localized nonlinear electrostatic perturbations observed in double-plasma machines, rf discharge plasma, noctilucent cloud region in Earths atmosphere, etc., where population of two thermal electrons can significantly dominate the wave dynamics, are also briefly addressed.
NASA Astrophysics Data System (ADS)
El-Hanbaly, A. M.; El-Shewy, E. K.; Sallah, M.; Darweesh, H. F.
2015-05-01
The propagation of linear and nonlinear dust acoustic waves in a homogeneous unmagnetized, collisionless and dissipative dusty plasma consisted of extremely massive, micron-sized, negative dust grains has been investigated. The Boltzmann distribution is suggested for electrons whereas vortex-like distribution for ions. In the linear analysis, the dispersion relation is obtained, and the dependence of damping rate of the waves on the carrier wave number , the dust kinematic viscosity coefficient and the ratio of the ions to the electrons temperatures is discussed. In the nonlinear analysis, the modified Korteweg-de Vries-Burgers (mKdV-Burgers) equation is derived via the reductive perturbation method. Bifurcation analysis is discussed for non-dissipative system in the absence of Burgers term. In the case of dissipative system, the tangent hyperbolic method is used to solve mKdV-Burgers equation, and yield the shock wave solution. The obtained results may be helpful in better understanding of waves propagation in the astrophysical plasmas as well as in inertial confinement fusion laboratory plasmas.
Radiative condensation instability in partially ionized dusty plasma with polarization force
NASA Astrophysics Data System (ADS)
Sharma, Prerana; Jain, Shweta
2016-01-01
This paper studies the effect of polarization force on the radiative condensation (RC) instability of a partially ionized dusty medium both in the presence and absence of self-gravitation. The temperature and density dependent heat loss function is considered in the process of heating and radiative cooling. The linear-perturbation analysis is used to derive general dispersion relation and criteria for both the Jeans and RC instability. The condition of Jeans instability is modified due to the RC, polarization force, magnetic field and dust thermal speed, whereas in the case of RC instability the instability criterion is modified due to the presence of dust thermal speed, magnetic field and polarization force. The effects of various parameters have been numerically estimated on RC instability. It is clear from figure that the presence of polarization parameter and density dependent heat-loss function destabilize the system while the presence of temperature dependent heat-loss function, dust neutral collision frequency and ratio of neutral dust density stabilize the system. These findings are relevant for many areas of space and laboratory plasma research prime examples being the formation of dense molecular clouds in interstellar and intergalactic medium, condensations in planetary nebulae and in laboratory plasmas like tokamak edge plasma.
Nonplanar dynamics of variable size dust grains in nonextensive dusty plasma
NASA Astrophysics Data System (ADS)
Behery, E. E.; Selim, M. M.; El-Taibany, W. F.
2015-11-01
The nonplanar propagation of variable size dust grains in an unmagnetized, collisionless nonplanar (cylindrical) dusty plasma is investigated. The plasma is composed of cold positive and negative dust fluids and nonextensively distributed ions and electrons. The dust size distribution (DSD) is proposed to obey a power law distribution function which is widely applicable in space plasmas. The reductive perturbation technique is employed, and a cylindrical Kadomtsev-Petviashvili equation, describing the nonlinear propagation of dust acoustic waves (DAWs), is obtained. New solutions of this evolution equation (hyperbolic, trigeometrical, and rational) are obtained using G ' / G -expansion method. In addition, the proposed model permits the two soliton types, i.e., the rarefactive and compressive solitons. It is found that the DSD and nonextensive distributions have drastic effects on the basic properties of the nonlinear cylindrical DAWs; the phase velocity, the amplitude, and the width. The applications of the present findings in certain astrophysics environments (such as Jupiter's magnetosphere and Earth's mesosphere), where both of the DSD and the geometrical effects are important, are discussed.
Experiments on 2D Vortex Patterns with a Photoinjected Pure Electron Plasma
NASA Astrophysics Data System (ADS)
Durkin, Daniel; Fajans, Joel
1998-11-01
The equations governing the evolution of a strongly magnetized pure electron plasma are analogous to those of an ideal 2D fluid; plasma density is analogous to fluid vorticity. Therefore, we can study vortex dynamics with pure electron plasmas. We generate our electron plasma with a photocathode electron source. The photocathode provides greater control over the initial profile than previous thermionic sources and allows us to create complicated initial density distributions, corresponding to complicated vorticity distributions in a fluid. Results on the stability of 2D vortex patterns will be presented: 1) The stability of N vortices arranged in a ring; 2) The stability of N vortices arranged in a ring with a central vortex; 3) The stability of more complicated vortex patterns.(http://socrates.berkeley.edu/ )fajans/
Gupta, Ruby; Sharma, Suresh C.; Prakash, Ved
2011-05-15
A density modulated electron beam propagating through a conductor-dusty plasma interface drives electromagnetic surface plasma waves (SPWs) to instability via Cerenkov and cyclotron interaction. The SPWs propagate across an external magnetic field parallel to the interface. Numerical calculations of the growth rate and unstable mode frequencies have been carried out for the typical parameters of the SPWs. The frequency and the growth rate of the unstable wave instability increase with the relative density of negatively charged dust grains {delta} (= n{sub io}/n{sub eo}, where n{sub io} is the ion plasma density and n{sub eo} is the electron plasma density). The phase velocity of the unstable waves also increases with {delta}. In addition, the growth rate of the instability increases with the beam density and scales as one-third power of the beam density in Cerenkov interaction and square root of beam density in fast cyclotron interaction. Moreover, the dispersion relation of SPWs has been retrieved in the absence of the modulated beam and without dust grains.
Effect of a floating circular aperture on a dc glow discharge dusty plasma
NASA Astrophysics Data System (ADS)
Heinrich, Jonathon R.; Kim, Su-Hyun; Merlino, Robert L.
2009-11-01
We have investigated novel effects observed when a floating aperture, either 6 mm or 8 mm in diameter, is placed 1-2 cm in front of an anode disk (4 cm diameter) that is used to form a dc glow discharge dusty plasma. Dust is incorporated into the anode glow plasma from a tray located below the anode which contained kaolin powder. The glow discharge traps particles with an average size of 1 micron. When the aperture is placed in front of the disk, well-defined pear-shaped or spherical dust clouds are formed, depending on the diameter of the aperture and its distance from the anode. The dust interacts with the aperture through the potential structure associated with the floating (negative) plate in which the aperture is located. The dust cloud is imaged using a CCD camera and a thin sheet of 532 nm laser light. Some of the effects observed include: outwardly expanding spherical dust acoustic waves and shocks, dust rotation around a void formed at the aperture, and a dust/discharge instability in which the discharge is periodically quenched and reignited while the dust cloud expands and contracts, with the dust retaining a residual charge.
The effect of a dust size distribution on electrostatic sheaths in unmagnetized dusty plasmas
Benlemdjaldi, D.; Tahraoui, A.; Hugon, R.; Bougdira, J.
2013-04-15
In this work, the structure of plasma sheaths in presence of dust particles with different sizes is investigated numerically in a multifluid framework, where the dust size distribution is modeled by Gauss' law. For this, we have established a 1D, stationary, unmagnetized, and weakly collisional electronegative dusty plasma sheath model. The electrons and negative ions are considered in a local thermodynamic equilibrium, therefore, described by a Boltzmann distribution. On the other hand, positive ions and dust grains are described by fluid equations. The charging process is described by the orbit motion limited model. It is shown that taking into account dust grains with different sizes reduces considerably the sheath thickness. The behavior of dust surface potential is not affected, but the dust charge number is reduced, as well as the electrostatic force. It results in a decrease of layered structure. The presence of negative ions makes the structure of the electrostatic potential more oscillatory. The other physical parameters are also analyzed and discussed.
Non-Markovian dynamics of dust charge fluctuations in dusty plasmas
NASA Astrophysics Data System (ADS)
Asgari, H.; Muniandy, S. V.; Ghalee, Amir; Ghalee
2014-06-01
Dust charge fluctuates even in steady-state uniform plasma due to the discrete nature of the charge carriers and can be described using standard Langevin equation. In this work, two possible approaches in order to introduce the memory effect in dust charging dynamics are proposed. The first part of the paper provides the generalization form of the fluctuation-dissipation relation for non-Markovian systems based on generalized Langevin equations to determine the amplitudes of the dust charge fluctuations for two different kinds of colored noises under the assumption that the fluctuation-dissipation relation is valid. In the second part of the paper, aiming for dusty plasma system out of equilibrium, the fractionalized Langevin equation is used to derive the temporal two-point correlation function of grain charge fluctuations which is shown to be non-stationary due to the dependence on both times and not the time difference. The correlation function is used to derive the amplitude of fluctuations for early transient time.
The magnetized sheath of a dusty plasma with nanosize dust grains
Mehdipour, H.; Foroutan, G.
2010-08-15
The magnetized sheath of a dusty plasma is investigated via numerical simulations of stationary multifluid equations by taking into account the electric, magnetic, gravitational, ion drag, neutral drag, and thermophoretic forces. Dependence of the sheath properties on the characteristics of the magnetic field and plasma parameters is explored. The sheath dynamics is mainly governed by the electric and ion drag forces and the effect of gravitation is negligible. The sheath demonstrates a nonmonotonic behavior against variations of the magnetic intensity and its angle of incidence. The sheath thickness and the maximum of dust density distribution decrease with increasing the ion to electron density ratio at the sheath edge, but increase with growing electron temperature and the positive temperature gradient of the neutrals. The effects of ion drag are similar to those of the gravitational force as both of them accelerate the dust to the wall. By a suitable configuration of the temperature gradient in the neutral gas, thermophoretic force can be utilized to deposit the building units of nanostructures on a substrate or remove any unwanted contaminant from its neighborhood.
Dispersion relation for pure dust Bernstein waves in a non-Maxwellian magnetized dusty plasma
Deeba, F.; Ahmad, Zahoor; Murtaza, G.
2011-07-15
Pure dust Bernstein waves are investigated using non-Maxwellian kappa and (r,q) distribution functions in a collisionless, uniform magnetized dusty plasma. Dispersion relations for both the distributions are derived by considering waves whose frequency is of the order of dust cyclotron frequency, and dispersion curves are plotted. It is observed that the propagation band for dust Bernstein waves is rather narrow as compared with that of the electron Bernstein waves. However, the band width increases for higher harmonics, for both kappa and (r,q) distributions. Effect of dust charge on dispersion curves is also studied, and one observes that with increasing dust charge, the dispersion curves shift toward the lower frequencies. Increasing the dust to ion density ratio ((n{sub d0}/n{sub i0})) causes the dispersion curve to shift toward the higher frequencies. It is also found that for large values of spectral index kappa ({kappa}), the dispersion curves approach to the Maxwellian curves. The (r,q) distribution approaches the kappa distribution for r = 0, whereas for r > 0, the dispersion curves show deviation from the Maxwellian curves as expected. Relevance of this work can be found in astrophysical plasmas, where non-Maxwellian velocity distributions as well as dust particles are commonly observed.
NASA Astrophysics Data System (ADS)
Rahman, O.
2015-12-01
The nonlinear propagation of dust-ion-acoustic (DIA) solitary waves (SWs) in an unmagnetized four-component dusty plasma containing electrons and negative ions obeying vortex-like (trapped) velocity distribution, cold mobile positive ions and arbitrarily charged stationary dust has been theoretically investigated. The properties of small but finite amplitude DIASWs are studied by employing the reductive perturbation technique. It has been found that owing to the departure from the Maxwellian electron and Maxwellian negative ion distribution to a vortex-like one, the dynamics of such DIASWs is governed by a modified Korteweg-de Vries (mKdV) equation which admits SW solution under certain conditions. The basic properties (speed, amplitude, width, etc.) of such DIASWs are found to be significantly modified by the presence of trapped electron and trapped negative ions. The implications of our results to space and laboratory dusty electronegative plasmas (DENPs) are briefly discussed.
Rahman, O.; Mamun, A. A.
2011-08-15
The nonlinear propagation of dust-ion-acoustic (DIA) waves in a dusty plasma containing trapped electrons following vortex-like distribution, cold mobile ions, and arbitrarily charged static dust is theoretically investigated. The properties of small but finite amplitude DIA solitary waves (SWs) are studied by employing the reductive perturbation technique. It is found that owing to the departure from the Maxwellian electron distribution to a vortex-like one, the dynamics of such DIA SWs is governed by a modified Korteweg-de Vries equation. The basic features (amplitude, width, speed, etc.) of such DIA SWs, which are found to be significantly modified by the vortex-like electron distribution and dust polarity, are also examined. The implications of our results to space and laboratory dusty plasmas are briefly discussed.
Alinejad, H.; Tribeche, M.
2010-12-15
A weakly nonlinear analysis is carried out to investigate the properties of dust ion-acoustic shock waves in a charge varying dusty plasma with vortexlike electron distribution. We use the ionization model, hot ions with equilibrium streaming speed and a trapped electron charging current derived from the well-known orbit limited motion theory. A new modified Burger equation is derived. Besides nonlinear trapping, this equation involves two kinds of dissipation (the anomalous one inherent to nonadiabatic dust charge fluctuation and the one due to the particle loss and ionization). These two kinds of dissipation can act concurrently. The traveling wave solution has been acquired by employing the modified extended tanh-function method. The shocklike solution is numerically analyzed based on the typical numerical data from laboratory dusty plasma devices. It is found that ion temperature, trapped particles, and weak dissipations significantly modify the shock structures.
NASA Astrophysics Data System (ADS)
Garai, S.; Jana, S.; Janaki, M. S.; Chakrabarti, N.
2016-06-01
A visco-elastic medium, such as a strongly coupled dusty plasma (SCDP), permits both the propagation of longitudinal dust acoustic mode due to compressibility and transverse shear mode due to elasticity. In the presence of finite velocity shear, these two modes get coupled with each other and eventually the coupled mode becomes unstable. In a non-Newtonian dust fluid, it has been found that the viscosity gradient has a modulating effect on this shear-driven instability under various parametric regimes. A detailed investigation has been carried out on the effect of viscosity gradient on the stability characteristics of a strongly coupled dusty plasma by using the conventional dust fluid equations; both analytically and numerically. These results can be helpful in understanding the phenomena associated with mechanical instabilities in highly viscous fluids; such as metallic glasses, Earth's mantle etc.
Gong Jingyu; Du Jiulin
2012-06-15
We study the secondary electron emissions induced by the impact of electrons on dust grains and the resulting dust charging processes in the nonequilibrium dusty plasma with power-law distributions. We derive new expressions of the secondary emitted electron flux and the dust charging currents that are generalized by the power-law q-distributions, where the nonlinear core functions are numerically studied for the nonextensive parameter q. Our numerical analyses show that the power-law q-distribution of the primary electrons has a significant effect on both the secondary emitted electron flux and the dust charging currents, and this effect depends strongly on the ratio of the electrostatic potential energy of the primary electrons at the dust grain's surface to the thermodynamic energy, implying that a competition in the dusty plasma between these two energies plays a crucial role in this novel effect.
El-Labany, S. K.; Selim, M. M. E-mail: mselim2000@yahoo.com; Al-Abbasy, O. M.; El-Bedwehy, N. A.
2015-02-15
The effects of adiabatic dust grain charge fluctuation and inhomogeneity on the nonlinear properties of dust acoustic (DA) solitary waves are studied. The plasma under consideration is a hot magnetized dusty plasma consisting of negatively charged dust particles, Boltzmann ions, and nonextensive electrons. A modified Zakharov-Kusnetsov equation, which admits a solitary wave solution, is derived using the reductive perturbation theory. It is found that the charge fluctuation of the dust grain modifies the nature of DA solitary structures. The numerical results may be useful to understand phenomena in laboratory and astrophysical plasmas.
NASA Astrophysics Data System (ADS)
Mayout, Saliha; Sahu, Biswajit; Tribeche, Mouloud
2015-12-01
A theoretical study on the nonlinear propagation of nonplanar (cylindrical and spherical) dust ion-acoustic solitary waves (DIASW) is carried out in a dusty plasma, whose constituents are inertial ions, superthermal electrons, and charge fluctuating stationary dust particles. Using the reductive perturbation theory, a modified Korteweg-de Vries equation is derived. It is shown that the propagation characteristics of the cylindrical and spherical DIA solitary waves significantly differ from those of their one-dimensional counterpart.
Mayout, Saliha; Tribeche, Mouloud; Sahu, Biswajit
2015-12-15
A theoretical study on the nonlinear propagation of nonplanar (cylindrical and spherical) dust ion-acoustic solitary waves (DIASW) is carried out in a dusty plasma, whose constituents are inertial ions, superthermal electrons, and charge fluctuating stationary dust particles. Using the reductive perturbation theory, a modified Korteweg-de Vries equation is derived. It is shown that the propagation characteristics of the cylindrical and spherical DIA solitary waves significantly differ from those of their one-dimensional counterpart.
NASA Astrophysics Data System (ADS)
Alam, M. S.; Masud, M. M.; Mamun, A. A.
2013-11-01
The basic properties of dust-ion-acoustic (DIA) shock waves in an unmagnetized dusty plasma (containing inertial ions, kappa distributed electrons with two distinct temperatures, and negatively charged immobile dust grains) are investigated both numerically and analytically. The hydrodynamic equation for inertial ions has been used to derive the Burgers equation. The effects of superthermal bi-kappa electrons and ion kinematic viscosity, which are found to modify the basic features of DIA shock waves significantly, are briefly discussed.
Two-dimensional phase transition in a strongly nonideal dusty plasma
Petrov, O. F. Vasiliev, M. M.; Tun, Ye; Statsenko, K. B.; Vaulina, O. S.; Vasilieva, E. V.; Fortov, V. E.
2015-02-15
We consider the results of experimental observation of melting of a plasma-dust monolayer (2D phase transition) in a low-pressure gas discharge. Pair and bond-angular correlation functions as well as the number of topological defects in the monolayer are measured and analyzed. The change of profile of the bond-angular correlation functions confirms the existence of the solid-hexatic phase-liquid phase transition, which completely correlates with the Berezinskii-Kosterlitz-Thouless theory.
NASA Astrophysics Data System (ADS)
Singh, Manpreet; Singh Saini, Nareshpal; Ghai, Yashika; Kaur, Nimardeep
2016-07-01
Dusty plasma is a fully or partially ionized gas which contain micron or sub-micron sized dust particles. These dust particles can be positively or negatively charged, depending upon the mechanism of charging . Dusty plasma is often observed in most of the space and astrophysical plasma environments. Presence of these dust particles can modify the dispersion properties of waves in the plasma and can introduce several new wave modes, e.g., dust acoustic (DA) waves, dust-ion acoustic (DIA) waves, dust-acoustic shock waves etc. In this investigation we have studied the small amplitude dust acoustic waves in an unmagnetized plasma comprising of electrons, positively charged ions, negatively charged hot as well as cold dust. Electrons and ions are described by superthermal distribution which is more appropriate for modeling space and astrophysical plasmas. Kadomtsev- Petviashvili (KP) equation has been derived using reductive perturbation technique. Positive as well as negative potential structures are observed, depending upon some critical values of parameters. Amplitude and width of dust acoustic solitary waves are modified by varying these parameters such as superthermality of electrons and ions, direction of propagation of the wave, relative concentration of hot and cold dust particles etc. This study may be helpful in understanding the formation and dynamics of nonlinear structures in various space and astrophysical plasma environments such Saturn's F-rings.
Conde, L.
2006-03-15
The large wavenumber suppression of unstable modes by space charge effects of the ionization instability in a weakly ionized and unmagnetized dusty plasma is investigated. The charge losses in the initial equilibrium state are balanced by electron impact ionizations originated by both the thermal electron populations and an additional monoenergetic electron beam. The multifluid dimensionless equations are deduced by using the time and length scales for elastic collisions between ions and neutral atoms and the Poisson equation relates the plasma potential fluctuations with charged particle densities instead of the quasineutral approximation. A general dimensionless dispersion relation is obtained from the linearized transport equations, where the ratios between the characteristic velocities, as the dust ion acoustic (IA), dust acoustic (DA), ion sound, and thermal speeds permits us to evaluate the weight of the different terms. In the long wavelength limit the results obtained using the quasineutral approximation are recovered. The differences found between roots of both dispersion equations are discussed, as well as those of previous models. The unstable mode of the linear ionization instability is originated by the imbalance between ion and electron densities in the rest state caused by the negative charging of dust grains. Contrary to dust free plasmas, the unstable mode exists, even in the absence of the ionizing electron beam. The numerical calculations of the roots of the full dispersion equation present a maximum unstable wavenumber not predicted by the quasineutral approximation, which is related with the minimum allowed length for space charge fluctuations within a fluid model. This upper limit of unstable wave numbers hinders the predicted resonant coupling in the long wavenumber regime between the DA and DIA waves.
Direct three-dimensional imaging of structure in a strongly-coupled dusty plasma
NASA Astrophysics Data System (ADS)
Quinn, R. A.; Goree, J.; Pieper, J. B.
1996-11-01
Using direct imaging of 9 μ m plastic spheres suspended in low-power Krypton discharges, we have constructed three-dimensional images showing the crystalline structure of a strongly-coupled dusty plasma. The spheres, which are highly charged and levitated by the electrode sheath, form a strongly-coupled system. A horizontal laser sheet illuminates a slice through the suspension, and a video camera views at 90^circ . Using a vertical stack of digitized images of particles in equally-spaced horizontal planes, we reconstructed the 3-D structure. We found bcc (body-centered cubic) and simple hexagonal structures coexisting in the same suspension. This coexistence is attributed to a bistability owing to an attractive potential region downstream of a charged grain in the presence of flowing ions. The probability of the system arranging in itself in the bcc or simple hexagonal phases is found to depend on the rf power that is used to sustain the discharge, and this in turn affects the particle charge and Debye length.(J. B. Pieper, J. Goree, R. A. Quinn, submitted to Phys. Rev. E) Work supported by NSF and NASA
Upper-hybrid wave-driven Alfvenic turbulence in magnetized dusty plasmas
Misra, A. P.; Banerjee, S.
2011-03-15
The nonlinear dynamics of coupled electrostatic upper-hybrid (UH) and Alfven waves (AWs) is revisited in a magnetized electron-ion plasma with charged dust impurities. A pair of nonlinear equations that describe the interaction of UH wave envelopes (including the relativistic electron mass increase) and the density as well as the compressional magnetic field perturbations associated with the AWs are solved numerically to show that many coherent solitary patterns can be excited and saturated due to modulational instability of unstable UH waves. The evolution of these solitary patterns is also shown to appear in the states of spatiotemporal coherence, temporal as well as spatiotemporal chaos, due to collision and fusion among the patterns in stochastic motion. Furthermore, these spatiotemporal features are demonstrated by the analysis of wavelet power spectra. It is found that a redistribution of wave energy takes place to higher harmonic modes with small wavelengths, which, in turn, results in the onset of Alfvenic turbulence in dusty magnetoplasmas. Such a scenario can occur in the vicinity of Saturn's magnetosphere as many electrostatic solitary structures have been observed there by the Cassini spacecraft.
Effects Of Relative Strength Of Dispersion On The Formation Of Nonlinear Waves In Dusty Plasmas
Asgari, H.; Muniandy, S. V.; Wong, C. S.; Yap, S. L.
2009-07-07
In this paper, we studied the effect of strength of dispersion on the formation of solitons and shock waves in un-magnetized dusty plasma using the reductive perturbative technique. Different relational forms of strength parameter epsilon were chosen such a way that it altered the stretching of space, x and time, t variables, thereby leading to different nonlinearities. First, we considered the form zeta = sq root(epsilon(x-v{sub 0}t)) and tau = sq root(epsilont), where v{sub 0} is the phase velocity, with 0
Dust-ion-acoustic double layers in multi-ion dusty plasma
Mamun, A. A.; Deeba, F.
2015-08-15
A theoretical investigation has been made on nonplanar (cylindrical and spherical) dust-ionacoustic (DIA) double layers (DLs) in a multi-ion dusty plasma system containing inertial positive and negative ions and arbitrarily charged stationary dust. The dust particles have been considered as arbitrarily (either positively or negatively) charged in order to observe the effects of the dust polarity on the DIA DLs. The ion species were considered to be at different temperatures to observe the effects of the temperatures on that waves. The modified Gardner equation, which has been derived by employing the reductive perturbation method, has been used to analyze time-dependent nonplanar and planar DIA DLs. It has been found that the time evolution of DIA DLs is significantly modified not only by the nonplanar geometry, but also by the polarity, temperature, and mass ratio of the constituent particles. It has been also found that the amplitude of cylindrical DIA DL structures is larger than that of 1D planar ones, but smaller than that of the spherical ones.
Dust-ion-acoustic double layers in multi-ion dusty plasma
NASA Astrophysics Data System (ADS)
Mamun, A. A.; Deeba, F.
2015-08-01
A theoretical investigation has been made on nonplanar (cylindrical and spherical) dust-ionacoustic (DIA) double layers (DLs) in a multi-ion dusty plasma system containing inertial positive and negative ions and arbitrarily charged stationary dust. The dust particles have been considered as arbitrarily (either positively or negatively) charged in order to observe the effects of the dust polarity on the DIA DLs. The ion species were considered to be at different temperatures to observe the effects of the temperatures on that waves. The modified Gardner equation, which has been derived by employing the reductive perturbation method, has been used to analyze time-dependent nonplanar and planar DIA DLs. It has been found that the time evolution of DIA DLs is significantly modified not only by the nonplanar geometry, but also by the polarity, temperature, and mass ratio of the constituent particles. It has been also found that the amplitude of cylindrical DIA DL structures is larger than that of 1D planar ones, but smaller than that of the spherical ones.
Dust ion-acoustic rogue waves in a three-species ultracold quantum dusty plasmas
Sun, Wen-Rong; Tian, Bo Liu, Rong-Xiang; Liu, De-Yin
2014-10-15
Dust ion-acoustic (DIA) rogue waves are reported for a three-component ultracold quantum dusty plasma comprised of inertialess electrons, inertial ions, and negatively charged immobile dust particles. The nonlinear Schrödinger (NLS) equation appears for the low frequency limit. Modulation instability (MI) of the DIA waves is analyzed. Influence of the modulation wave number, ion-to-electron Fermi temperature ratio ρ and dust-to-ion background density ratio N{sub d} on the MI growth rate is discussed. The first- and second-order DIA rogue-wave solutions of the NLS equation are examined numerically. It is found that the enhancement of N{sub d} and carrier wave number can increase the envelope rogue-wave amplitudes. However, the increase of ρ reduces the envelope rogue-wave amplitudes. - Highlights: • The nonlinear Schrödinger equation is derived for the low frequency limit. • Modulational instability growth rate is discussed. • The first- and second-order dust ion-acoustic rogue waves are examined numerically.
NASA Astrophysics Data System (ADS)
Pulinets, Sergey; Ouzounov, Dimitar
Natural radioactivity of the Earth through ionization creates a large number of new ions in the boundary layer of atmosphere from the ground surface up to near 1 km altitude. In specific conditions the ion concentration can reach 10 (6) -10 (7) cm (-3) . This sharp increase of ion concentration leads to the process of so called Ion Induced Nucleation (IIN) when due to ion's hydration the large complex ion clusters are formed with the very low recombination rate, i.e. we deal with formation of dusty atmospheric plasma in the boundary layer. Our theoretical estimates and experimental results of ground based and remote sensing satellite monitoring revealed two main consequences of IIN: release of large amount of the latent heat leading to the changes of air temperature and humidity, and sharp changes of air conductivity in the vertical column of the Global Electric Circuit (GEC) leading to formation of large scale irregularities of electron concentration in the ionosphere. The mechanism has universal character and its effects are observed in different natural and anthropogenic disasters like hurricanes, earthquakes, volcano eruption, artificial ionization, emergencies at atomic power plants, etc. Experimental evidences for many cases demonstrating effects of IIN are presented.
NASA Astrophysics Data System (ADS)
Yang, Chi; Wang, Wen; I, Lin
2016-01-01
We experimentally investigate the spatiotemporal dynamical behaviors of the avalanche structural rearrangement through micro-cracking-healing in weakly stressed cold dusty plasma liquids, and the kinetic origins for their different spatial and temporal classifications. The crystalline ordered domains can be cracked or temporarily sustain and transfer the weak stress to remote regions for cracking-healing. It is found that cracking sites form a fractal network with cluster size following power law distribution in the x y t space. The histograms of the persistent times for sustaining regional ordered and disordered structure, the temporal cracking burst width, and quiescent time between two bursts all follow power law decays with fast descending tails. Cracking can be classified into a single temporal burst with simple line like spatial patterns and the successive cracking fluctuation with densely packed cracking clusters. For an ordered region, whether the Burgers vectors of the incoming dislocations from the boundary allow direct dislocation reduction is the key for the above two classifications through cracking a large ordered domain into medium scale corotating ordered domains or small patches. The low regional structural order at the end of a cracking burst can be regarded as an alarm for predicting the short quiescent period before the next cracking burst.
Chang, Mei-Chu; Tseng, Yu-Ping; I, Lin
2011-03-15
The microscopic channeling dynamics of projectiles in subexcitable chain bundle dusty plasma liquids consisting of long chains of negatively charged dusts suspended in low pressure glow discharges is investigated experimentally using fast video-microscopy. The long distance channeling of the projectile in the channel formed by the surrounding dust chain bundles and the excitation of a narrow wake associated with the elliptical motions of the background dusts are demonstrated. In the high projectile speed regime, the drag force due to wake wave excitation increases with the decreasing projectile speed. The excited wave then leads the slowed down projectile after the projectile speed is decreased below the resonant speed of wave excitation. The wave-projectile interaction causes the increasing projectile drag below the resonant speed and the subsequent oscillation around a descending average level, until the projectile settles down to the equilibrium point. Long distance projectile surfing through the resonant crest trapping by the externally excited large amplitude solitary wave is also demonstrated.
Perpendicular diffusion of a dilute beam of charged particles in the PK-4 dusty plasma
NASA Astrophysics Data System (ADS)
Liu, Bin; Goree, John
2015-09-01
We study the random walk of a dilute beam of projectile dust particles that drift through a target dusty plasma. This random walk is a diffusion that occurs mainly due to Coulomb collisions with target particles that have a different size. In the direction parallel to the drift, projectiles exhibit mobility-limited motion with a constant average velocity. We use a 3D molecular dynamics (MD) simulation of the dust particle motion to determine the diffusion and mobility coefficients for the dilute beam. The dust particles are assumed to interact with a shielded Coulomb repulsion. They also experience gas drag. The beam particles are driven by a prescribed net force that is not applied to the target particles; in the experiments this net force is due to an imbalance of the electric and ion drag forces. This simulation is motivated by microgravity experiments, with the expectation that the scattering of projectiles studied here will be observed in upcoming PK-4 experiments on the International Space Station. Supported by NASA and DOE.
Upper-hybrid wave-driven Alfvénic turbulence in magnetized dusty plasmas.
Misra, A P; Banerjee, S
2011-03-01
The nonlinear dynamics of coupled electrostatic upper-hybrid (UH) and Alfvén waves (AWs) is revisited in a magnetized electron-ion plasma with charged dust impurities. A pair of nonlinear equations that describe the interaction of UH wave envelopes (including the relativistic electron mass increase) and the density as well as the compressional magnetic field perturbations associated with the AWs are solved numerically to show that many coherent solitary patterns can be excited and saturated due to modulational instability of unstable UH waves. The evolution of these solitary patterns is also shown to appear in the states of spatiotemporal coherence, temporal as well as spatiotemporal chaos, due to collision and fusion among the patterns in stochastic motion. Furthermore, these spatiotemporal features are demonstrated by the analysis of wavelet power spectra. It is found that a redistribution of wave energy takes place to higher harmonic modes with small wavelengths, which, in turn, results in the onset of Alfvénic turbulence in dusty magnetoplasmas. Such a scenario can occur in the vicinity of Saturn's magnetosphere as many electrostatic solitary structures have been observed there by the Cassini spacecraft. PMID:21517632
Bohm criterion in a dusty plasma with nonextensive electrons and cold ions
Liu, Y.; Zhou, L.; Liu, S. Q.
2013-04-15
The Bohm criterion in a dusty plasma containing nonextensively distributed electrons and cold ions is investigated within the framework of probe model including the effects of dust charge fluctuation. It is shown that the critical Mach number upshifts with the decrease of electron nonextensive parameter (q{sub e}) and the increase of the ion-to-electron number density ratio (R{sub n}) when the effects of dust charge fluctuation are out of consideration. Once the effects of dust charge fluctuation are included, with the increase of R{sub n}, the critical Mach number increases first, then decreases. The slop of the critical Mach number curves in the region R{sub n} Much-Greater-Than 1 for q{sub e}>1 becomes more gradual than that for q{sub e}<1. When critical Mach number is defined with respect to modified ion acoustic wave speed, it should be larger than unity in the case free of dust charge fluctuation. Whereas when R{sub n} Much-Greater-Than 1, it may be smaller than unity due to the effect of dust charge fluctuation.
Instability of plasma waves during relaxation of 2D turbulent flows
NASA Astrophysics Data System (ADS)
Kabantsev, A. A.; Drsicoll, C. F.
2015-11-01
We observe strong excitation of novel low-frequency z-dependent plasma waves (mθ = 0 ,kz = 1) , occurring during the nominally 2D relaxation of turbulent initial conditions (10 -100 interacting vortices) in strongly magnetized electron columns. This initial relaxation often results in ``2D vortex crystal'' states. Here we describe experiments showing the concomitant growth of ill-understood low-frequency plasma waves, probably due to ``leakage'' of 2D turbulent potential energy into z-dependent fluctuations. With plasma injection, the lowest regular Trivelpiece- Gould mode (mθ = 0 ,kz = 1) is observed at fTG (t) ~ 2 . 8 MHz and exponential decay time τTG ~ 1 msec. Also, we observe rapid exponential growth of a novel low-frequency mode with fLF (t) ~ 0 . 3 MHz, nominally also with mθ = 0 ,kz = 1 . In a few milliseconds (several tens of rotation times at B = 10kG), the LF-mode becomes highly nonlinear, developing up to a dozen temporal harmonics. When a LF-harmonic resonates with the decaying TG-mode, LF-mode energy is transferred into the TG-mode, and both modes remain at moderate amplitudes until the 2D turbulent relaxation abates (hundreds of rotation times). The ill-understood fLF is independent of B, even though the growth and duration times follow scale as B1 from the 2D flows. Supported by National Science Foundation Grant PHY-1414570, Department of Energy Grants DE-SC0008693.
Phase Transitions in a Capacitively Coupled Dusty Plasma with Conducting Dust
NASA Astrophysics Data System (ADS)
Carmona-Reyes, Jorge; Matthews, Lorin; Hyde, Truell
2011-10-01
Complex plasma is present in a variety of environments including planetary rings, cometary tails, interplanetary clouds and semiconductor manufacturing and fusion environments. Understanding the physics behind such complex plasmas, particularly those comprised of conducting dust, is not well understood. In this work, a GEC reference cell is employed to examine the translational and orientational order of conducting dust contained within crystal lattice structures formed in a complex plasma. The Pair Correlation function, bond orientation function and Voronoi and polygon construction diagrams are used to measure dislocations and disclinations, yielding a quantitative measure of the overall phase of the structure. The role this phase transition process plays in the melting of conducting and non-conducting 2D structures will be discussed.
NASA Astrophysics Data System (ADS)
Akbari-Moghanjoughi, M.
2012-06-01
More recently, Roy et al. [Phys. Plasmas 19, 033705 (2012)] have investigated the occurrence of nonlinear solitary and double-layers in an ultrarelativistic dusty electron-positron-ion degenerate plasma using a Sagdeev potential method. They have considered a full parametric examination on Mach-number criteria for existence of such nonlinear excitations using the specific degeneracy limits of Chandrasekhar equation of state (EoS) for Fermi-Dirac plasmas. In this comment, we point-out a misleading extension of polytropic EoS to study the Fermi-Dirac relativistically degenerate plasmas.
Akbari-Moghanjoughi, M.
2012-06-15
More recently, Roy et al.[Phys. Plasmas 19, 033705 (2012)] have investigated the occurrence of nonlinear solitary and double-layers in an ultrarelativistic dusty electron-positron-ion degenerate plasma using a Sagdeev potential method. They have considered a full parametric examination on Mach-number criteria for existence of such nonlinear excitations using the specific degeneracy limits of Chandrasekhar equation of state (EoS) for Fermi-Dirac plasmas. In this comment, we point-out a misleading extension of polytropic EoS to study the Fermi-Dirac relativistically degenerate plasmas.
2D Doppler backscattering using synthetic aperture microwave imaging of MAST edge plasmas
NASA Astrophysics Data System (ADS)
Thomas, D. A.; Brunner, K. J.; Freethy, S. J.; Huang, B. K.; Shevchenko, V. F.; Vann, R. G. L.
2016-02-01
Doppler backscattering (DBS) is already established as a powerful diagnostic; its extension to 2D enables imaging of turbulence characteristics from an extended region of the cut-off surface. The Synthetic Aperture Microwave Imaging (SAMI) diagnostic has conducted proof-of-principle 2D DBS experiments of MAST edge plasma. SAMI actively probes the plasma edge using a wide (±40° vertical and horizontal) and tuneable (10-34.5 GHz) beam. The Doppler backscattered signal is digitised in vector form using an array of eight Vivaldi PCB antennas. This allows the receiving array to be focused in any direction within the field of view simultaneously to an angular range of 6-24° FWHM at 10-34.5 GHz. This capability is unique to SAMI and is a novel way of conducting DBS experiments. In this paper the feasibility of conducting 2D DBS experiments is explored. Initial observations of phenomena previously measured by conventional DBS experiments are presented; such as momentum injection from neutral beams and an abrupt change in power and turbulence velocity coinciding with the onset of H-mode. In addition, being able to carry out 2D DBS imaging allows a measurement of magnetic pitch angle to be made; preliminary results are presented. Capabilities gained through steering a beam using a phased array and the limitations of this technique are discussed.
Landau damping of Gardner solitons in a dusty bi-ion plasma
NASA Astrophysics Data System (ADS)
Misra, A. P.; Barman, Arnab
2015-07-01
The effects of linear Landau damping on the nonlinear propagation of dust-acoustic solitary waves (DASWs) are studied in a collisionless unmagnetized dusty plasma with two species of positive ions. The extremely massive, micron-seized, cold, and negatively charged dust particles are described by fluid equations, whereas the two species of positive ions, namely, the cold (heavy) and hot (light) ions are described by the kinetic Vlasov equations. Following Ott and Sudan [Phys. Fluids 12, 2388 (1969)], and by considering lower and higher-order perturbations, the evolution of DASWs with Landau damping is shown to be governed by Korteweg-de Vries (KdV), modified KdV (mKdV), or Gardner (KdV-mKdV)-like equations. The properties of the phase velocity and the Landau damping rate of DASWs are studied for different values of the ratios of the temperatures (σ) and the number densities (μ) of hot and cold ions as well as the cold to hot ion mass ratio m. The distinctive features of the decay rates of the amplitudes of the KdV, mKdV, and Gardner solitons with a small effect of Landau damping are also studied in different parameter regimes. It is found that the Gardner soliton points to lower wave amplitudes than the KdV and mKdV solitons. The results may be useful for understanding the localization of solitary pulses and associated wave damping (collisionless) in laboratory and space plasmas (e.g., the F-ring of Saturn), in which the number density of free electrons is much smaller than that of ions and the heavy, micron seized dust grains are highly charged.
NASA Astrophysics Data System (ADS)
Thomas, Edward; Konopka, Uwe; Lynch, Brian; Adams, Stephen; LeBlanc, Spencer; Merlino, Robert L.; Rosenberg, Marlene
2015-11-01
Dusty plasmas have been studied in argon, radio frequency (rf) glow discharge plasmas at magnetic fields up to 2.5 T where the electrons and ions are strongly magnetized. Plasmas are generated between two parallel plate electrodes where the lower, powered electrode is solid and the upper electrode supports a dual mesh consisting of #24 brass and #30 aluminum wire cloth. In this experiment, we study the formation of imposed ordered structures and particle dynamics as a function of magnetic field. Through observations of trapped particles and the quasi-discrete (i.e., "hopping") motion of particles between the trapping locations, it is possible to make a preliminary estimate of the potential structure that confines the particles to a grid structure in the plasma. This information is used to gain insight into the formation of the imposed grid pattern of the dust particles in the plasma.
Thomas, Edward Konopka, Uwe; Lynch, Brian; Adams, Stephen; LeBlanc, Spencer; Merlino, Robert L.; Rosenberg, Marlene
2015-11-15
Dusty plasmas have been studied in argon, radio frequency (rf) glow discharge plasmas at magnetic fields up to 2.5 T where the electrons and ions are strongly magnetized. Plasmas are generated between two parallel plate electrodes where the lower, powered electrode is solid and the upper electrode supports a dual mesh consisting of #24 brass and #30 aluminum wire cloth. In this experiment, we study the formation of imposed ordered structures and particle dynamics as a function of magnetic field. Through observations of trapped particles and the quasi-discrete (i.e., “hopping”) motion of particles between the trapping locations, it is possible to make a preliminary estimate of the potential structure that confines the particles to a grid structure in the plasma. This information is used to gain insight into the formation of the imposed grid pattern of the dust particles in the plasma.
Experiments with an rf dusty plasma and an external plasma jet
NASA Astrophysics Data System (ADS)
Ticoş, C. M.
2010-12-01
A plasma jet produced in a coaxial plasma gun was aimed at a cloud of dust particles levitated in the sheath of a radio-frequency (rf) plasma produced between two parallel-plate electrodes. A high-speed camera with a side-view on the dust cloud was used to track the dust particles. Several cases of dust motion could be observed. When the jet was parallel with the horizontal electrodes of the rf plasma the dust particles were either pushed out of the trapping region by the plasma jet or were only perturbed from their equilibrium position, oscillating with a frequency of the order of a few kHz. In the first case the trajectory of the dust particles followed the curvature of the sheath. In the second case, when the jet was fired at a small angle with the horizontal electrodes the dust particles hit the bottom electrode and ricocheted back into the sheath. Finally, another situation was observed when the jet perturbed the rf plasma and its sheath and the whole dust crystal fell to the electrode.
NASA Astrophysics Data System (ADS)
Shahmansouri, M.; Mamun, A. A.
2015-07-01
The effects of strong electrostatic interaction among highly charged dust on multi-dimensional instability of dust-acoustic (DA) solitary waves in a magnetized strongly coupled dusty plasma by small- k perturbation expansion method have been investigated. We found that a Zakharov-Kuznetsov equation governs the evolution of obliquely propagating small amplitude DA solitary waves in such a strongly coupled dusty plasma. The parametric regimes for which the obliquely propagating DA solitary waves become unstable are identified. The basic properties, viz., amplitude, width, instability criterion, and growth rate, of these obliquely propagating DA solitary structures are found to be significantly modified by the effects of different physical strongly coupled dusty plasma parameters. The implications of our results in some space/astrophysical plasmas and some future laboratory experiments are briefly discussed.
NASA Astrophysics Data System (ADS)
Prajapati, R. P.; Bhakta, S.
2015-10-01
The influence of dust charge fluctuation, thermal speed and polarization force due to massive charged dust grains is studied on the radiative condensation instability (RCI) of magnetized self-gravitating astrophysical dusty (complex) plasma. The dynamics of the charged dust and inertialess electrons are considered while the Boltzmann distributed ions are assumed to be thermal. The dusty fluid model is formulated and the general dispersion relations are derived analytically using the plane wave solutions under the long wavelength limits in both the presence and the absence of dust charge fluctuations. The combined effects of polarization force, dust thermal speed, dust charge fluctuation and dust cyclotron frequency are observed on the low frequency wave modes and radiative modified Jeans Instability. The classical criterion of RCI is also derived which remains unaffected due to the presence of these parameters. Numerical calculations have been performed to calculate the growth rate of the system and plotted graphically. We find that dust charge fluctuation, radiative cooling and polarization force have destabilizing while dust thermal speed and dust cyclotron frequency have stabilizing influence on the growth rate of Jeans instability. The results have been applied to understand the radiative cooling process in dusty molecular cloud when both the dust charging and polarization force are dominant.
Shielding effect and wakefield pattern of a moving test charge in a non-Maxwellian dusty plasma
Ali, S.; Khan, S.
2013-07-15
By using the Vlasov-Poisson equations, we calculate an expression for the electrostatic potential caused by a test charge in an unmagnetized non-Maxwellian dusty plasma, whose constituents are the superthermal hot-electrons, the mobile cold-electrons with a neutralizing background of cold ions, and charge fluctuating isolated dust grains. The superthermality effects due to hot electrons not only modify the dielectric constant of the electron-acoustic waves but also significantly affect the electrostatic potential. The latter can be decomposed into the Debye-Hückel and oscillatory wake potentials. Analytical and numerical results reveal that the Debye-Hückel and wakefield potentials converge to the Maxwellian case for large values of superthermality parameter. Furthermore, the plasma parameters play a vital role in the formation of shielding and wakefield pattern in a two-electron temperature plasma. The present results should be important for laboratory and space dusty plasmas, where hot-electrons can be assumed to follow the non-Maxwellian distribution function.
Nonplanar dust-acoustic Gardner solitons in a four-component dusty plasma.
Mannan, A; Mamun, A A
2011-08-01
The nonlinear propagation of Gardner solitons (GSs) in a nonplanar (cylindrical and spherical) four-component dusty plasma (composed of inertial positively and negatively dust, Boltzmann electrons, and ions) is studied by the reductive perturbation method. The modified Gardner equation is derived and numerically solved. It has been found that the basic characteristics of the dust-acoustic (DA) GSs, which are shown to exist for μ around its critical value μ(c) [where μ=Z(dp)m(dn)/Z(dn)m(dp), Z(dn) (Z(dp)) is the number of electrons (protons) residing on a negative (positive) dust, m(dp) (m(dn)) is the mass of the positive (negative) dust, μ(c) is the value of μ corresponding to the vanishing of the nonlinear coefficient of the Korteweg-de Vries (KdV) equation, e.g., μ(c)≃0.174 for μ(e)=n(e0)/Z(dn)n(dn0)=0.2, μ(i)=n(i0)/Z(d)}n(dn0)=0.4, and σ=T(i)/T(e)=0.1, n(e0), n(i0), and n(dn0) are, respectively, electron, ion, and dust number densities, and T(i) (T(e)) is the ion (electron) temperature], are different from those of the KdV solitons, which do not exist for μ around μ(c). It has been also found that the propagation characteristics of nonplanar DA GSs significantly differ from those of planar ones. PMID:21929121
Solitonic and chaotic behaviors for the nonlinear dust-acoustic waves in a magnetized dusty plasma
NASA Astrophysics Data System (ADS)
Zhen, Hui-Ling; Tian, Bo; Xie, Xi-Yang; Wu, Xiao-Yu; Wen, Xiao-Yong
2016-05-01
A model for the nonlinear dust-ion-acoustic waves in a two-ion-temperature, magnetized dusty plasma is studied in this paper. Via the symbolic computation, one-, two- and N-soliton solutions are obtained. It is found that when √{μeμi }<2 T/i2 Te2 +T/i Te , the soliton amplitude is positively related to μe, μi, Ti, Zd, and B0, but inversely related to Te and md, with Te, Ti, μe, and μi as the temperature of an electron, temperature of a positive ion, normalized initial density of electrons, and normalized initial density of positive ions, respectively, Zd, B0, and md as the charge number of a dust particle, strength of the static magnetic field, and mass of a dust particle, respectively. It is also found that the two solitons are always parallel during the propagation on the x - y, x - t, and y - t planes, where x, y, and z are the scaled spacial coordinates, and t is the retarded time. Upon the introduction of the driving force Γ(t ) , both the developed and weak chaotic motions as well as the effect of Γ(t ) are explored. Via the phase projections and power spectra, we find the difference between the two chaotic motions roots in the relative magnitude of nonlinearity and external force. Increasing the frequency of the external force or the strength of the damped term can weaken the chaotic motions of such a forced model.
Nonplanar dust-acoustic Gardner solitons in a four-component dusty plasma
Mannan, A.; Mamun, A. A.
2011-08-15
The nonlinear propagation of Gardner solitons (GSs) in a nonplanar (cylindrical and spherical) four-component dusty plasma (composed of inertial positively and negatively dust, Boltzmann electrons, and ions) is studied by the reductive perturbation method. The modified Gardner equation is derived and numerically solved. It has been found that the basic characteristics of the dust-acoustic (DA) GSs, which are shown to exist for {mu} around its critical value {mu}{sub c}[where {mu}=Z{sub dp}m{sub dn}/Z{sub dn}m{sub dp}, Z{sub dn} (Z{sub dp}) is the number of electrons (protons) residing on a negative (positive) dust, m{sub dp} (m{sub dn}) is the mass of the positive (negative) dust, {mu}{sub c} is the value of {mu} corresponding to the vanishing of the nonlinear coefficient of the Korteweg-de Vries (KdV) equation, e.g., {mu}{sub c}{approx_equal}0.174 for {mu}{sub e}=n{sub e0}/Z{sub dn}n{sub dn0}=0.2, {mu}{sub i}=n{sub i0}/Z{sub dn}n{sub dn0}=0.4, and {sigma}=T{sub i}/T{sub e}=0.1, n{sub e0}, n{sub i0}, and n{sub dn0} are, respectively, electron, ion, and dust number densities, and T{sub i} (T{sub e}) is the ion (electron) temperature], are different from those of the KdV solitons, which do not exist for {mu} around {mu}{sub c}. It has been also found that the propagation characteristics of nonplanar DA GSs significantly differ from those of planar ones.
A 2-D Self-Consistent DSMC Model for Chemically Reacting Low Pressure Plasma Reactors
Bartel, Timothy J.; Economou, Demetre; Johannes, Justine E.
1999-06-17
This paper will focus on the methodology of using a 2D plasma Direct Simulation Monte Carlo technique to simulate the species transport in an inductively coupled, low pressure, chemically reacting plasma system. The pressure in these systems is typically less than 20 mtorr with plasma densities of approximately 10{sup 17} {number_sign}/m{sup 3} and an ionization level of only 0.1%. This low ionization level tightly couples the neutral, ion, and electron chemistries and interactions in a system where the flow is subsonic. We present our strategy and compare simulation results to experimental data for Cl{sub 2} in a Gaseous Electronics Conference (GEC) reference cell modified with an inductive coil.
Wavelet characterization of 2D turbulence and intermittency in magnetized electron plasmas
NASA Astrophysics Data System (ADS)
Romé, M.; Chen, S.; Maero, G.
2016-06-01
A study of the free relaxation of turbulence in a two-dimensional (2D) flow is presented, with a focus on the role of the initial vorticity conditions. Exploiting a well-known analogy with 2D inviscid incompressible fluids, the system investigated here is a magnetized pure electron plasma. The dynamics of this system are simulated by means of a 2D particle-in-cell code, starting from different spiral density (vorticity) distributions. A wavelet multiresolution analysis is adopted, which allows the coherent and incoherent parts of the flow to be separated. Comparison of the turbulent evolution in the different cases is based on the investigation of the time evolution of statistical properties, including the probability distribution functions and structure functions of the vorticity increments. It is also based on an analysis of the enstrophy evolution and its spectrum for the two components. In particular, while the statistical features assess the degree of flow intermittency, spectral analysis allows us not only to estimate the time required to reach a state of fully developed turbulence, but also estimate its dependence on the thickness of the initial spiral density distribution, accurately tracking the dynamics of both the coherent structures and the turbulent background. The results are compared with those relevant to annular initial vorticity distributions (Chen et al 2015 J. Plasma Phys. 81 495810511).
NASA Astrophysics Data System (ADS)
Ali, S.; Nasim, M. H.; Murtaza, G.
2003-11-01
The expressions for the Debye and the wake potential are derived by incorporating dust-charge fluctuations of a single projectile, as well as of an array of dust grain projectiles, propagating through a partially ionized dusty plasma with a constant velocity. Numerically, the effects of the dust-charge fluctuations and the dust-neutral collisions on the electrostatic potential for a single, three, six and ten projectiles are examined. The dust-charge relaxation rate modifies the shape of the Debye as well as the wake potential. For smaller values of the relaxation rates a potential well is formed instead of Debye potential.
Song, Y. L.; Huang, F.; He, Y. F.; Wu, L.; Liu, Y. H.; Chen, Z. Y.; Yu, M. Y.
2015-06-15
Influence of the system temperature on the micro-structures and dynamics of dust clusters in dusty plasmas is investigated through laboratory experiment and molecular dynamics simulation. The micro-structures, defect numbers, and pair correlation function of the dust clusters are studied for different system temperatures. The dust grains' trajectories, the mean square displacement, and the corresponding self-diffusion coefficient of the clusters are calculated for different temperatures for illustrating the phase properties of the dust clusters. The simulation results confirm that with the increase in system temperature, the micro-structures and dynamics of dust clusters are gradually changed, which qualitatively agree with experimental results.
NASA Astrophysics Data System (ADS)
Gao, Dong-Ning; Qi, Xin; Hong, Xue-Ren; Yang, Xue; Duan, Wen-Shan; Yang, Lei; Yang
2014-06-01
Numerical and theoretical investigations are carried out for the stability of the dust acoustic waves (DAWs) under the transverse perturbation in a two-ion temperature magnetized and collisionless dusty plasma. The Zakharov-Kuznetsov (ZK) equation, modified ZK equation, and Extended ZK (EZK) equation of the DAWs are given by using the reductive perturbation technique. The cut-off frequency is obtained by applying higher-order transverse perturbations to the soliton solution of the EZK equation. The propagation velocity of solitary waves, the real cut-off frequency, as well as the growth rate of the higher-order perturbation to the solitary wave are obtained.
Benzekka, Moufida; Tribeche, Mouloud
2013-08-15
Dust acoustic (DA) solitons are addressed in a charge varying dusty plasma in the presence of ion nonthermality and background nonextensivity. A physically meaningful nonthermal nonextensive ion distribution is outlined. The correct non-Maxwellian ion charging current is derived based on the orbit-limited motion theory. Under grain-current balance, the variable dust charge is expressed in terms of the Lambert function. It is found that nonthermality and its nonextensive nature may act concurrently and influence the restoring force and hence the soliton profile. Due to the flexibility provided by the nonextensive parameter, we think that our model should provide a better fit of the space observations.
Dust-ion acoustic shock waves in a dusty multi-ion plasma with negatively dust-charge fluctuation
NASA Astrophysics Data System (ADS)
Wang, Hongyan; Zhang, Kaibiao
2015-01-01
The nonlinear propagation of dust-ion acoustic shock waves in a collisionless, unmagnetized multi-ion dusty plasma contains Botlzemann-distributed electrons, negative and positive ions with extremely massive and stationary negative charge dust grains with dust charge fluctuations is investigated. By employing the reductive perturbation method, we obtain a Burgers equation that describes the two-ion fluid dynamics. The dust charge variation is found to play an important role in the formation of such dust-ion acoustic shock structures. The viscosity only affects the thickness of the shock waves. The dependences of the shock wave's velocity, height and thickness on the system parameters are investigated.
A gedankenexperiment for anomalous diffusion in a charge-fluctuating dusty plasma
Kopp, Andreas; Shchekinov, Yuri A.
2014-02-15
possible prototype of anomalous diffusion. We discuss briefly possible implications to space and astrophysical dusty plasma. In particular, we show that in a plasma with polydisperse dust particles, a superposition of the three regimes of the anomalous diffusion can simultaneously come into play.
Berbri, Abderrezak; Tribeche, Mouloud
2009-05-15
A weakly nonlinear analysis is carried out to derive a Korteweg-de Vries Burgers-like equation for small but finite amplitude dust ion-acoustic (DIA) waves in a charge varying dusty plasma with non thermally distributed electrons. The correct expression for the nonthermal electron charging current is used. Interestingly, it may be noted that due to electron nonthermality and finite equilibrium ion streaming velocity, the present dusty plasma model can admit compressive as well as rarefactive DIA solitary waves. Furthermore, there may exist DIA shocks which have either monotonic or oscillatory behavior and the properties of which depend sensitively on the number of fast nonthermal electrons. Our results should be useful to understand the properties of localized DIA waves that may occur in space dusty plasmas.
Alam, M. S.; Masud, M. M.; Mamun, A. A.
2013-12-15
A rigorous theoretical investigation has been performed on the propagation of cylindrical and spherical Gardner solitons (GSs) associated with dust-ion-acoustic (DIA) waves in a dusty plasma consisting of inertial ions, negatively charged immobile dust, and two populations of kappa distributed electrons having two distinct temperatures. The well-known reductive perturbation method has been used to derive the modified Gardner (mG) equation. The basic features (amplitude, width, polarity, etc.) of nonplanar DIA modified Gardner solitons (mGSs) have been thoroughly examined by the numerical analysis of the mG equation. It has been found that the characteristics of the nonplanar DIA mGSs significantly differ from those of planar ones. It has been also observed that kappa distributed electrons with two distinct temperatures significantly modify the basic properties of the DIA solitary waves and that the plasma system under consideration supports both compressive and rarefactive DIA mGSs. The present investigation should play an important role for understanding localized electrostatic disturbances in space and laboratory dusty plasmas where stationary negatively charged dust, inertial ions, and superthermal electrons with two distinct temperatures are omnipresent ingredients.
Dispersion properties of a 2D magnetized plasma metallic photonic crystal
Fu, T.; Yang, Z.; Shi, Z.; Lan, F.; Li, D.; Gao, X.
2013-02-15
This is a study on a 2D magnetized plasma-filled metal photonic crystal (PMPC). We analyze the dispersion relation of the magnetized PMPC by using the finite-difference time-domain method. Results show a cutoff frequency for the PMPC, and two flat bands and new forbidden band gaps appear due to the external magnetic field. Adjusting the external magnetic field can control the positions of the flat bands, cutoff frequency, and location and width of the local gap. These results provide theoretical basis for designing tunable photonic crystal devices.
Intracellular ROS mediates gas plasma-facilitated cellular transfection in 2D and 3D cultures
Xu, Dehui; Wang, Biqing; Xu, Yujing; Chen, Zeyu; Cui, Qinjie; Yang, Yanjie; Chen, Hailan; Kong, Michael G.
2016-01-01
This study reports the potential of cold atmospheric plasma (CAP) as a versatile tool for delivering oligonucleotides into mammalian cells. Compared to lipofection and electroporation methods, plasma transfection showed a better uptake efficiency and less cell death in the transfection of oligonucleotides. We demonstrated that the level of extracellular aqueous reactive oxygen species (ROS) produced by gas plasma is correlated with the uptake efficiency and that this is achieved through an increase of intracellular ROS levels and the resulting increase in cell membrane permeability. This finding was supported by the use of ROS scavengers, which reduced CAP-based uptake efficiency. In addition, we found that cold atmospheric plasma could transfer oligonucleotides such as siRNA and miRNA into cells even in 3D cultures, thus suggesting the potential for unique applications of CAP beyond those provided by standard transfection techniques. Together, our results suggest that cold plasma might provide an efficient technique for the delivery of siRNA and miRNA in 2D and 3D culture models. PMID:27296089
Intracellular ROS mediates gas plasma-facilitated cellular transfection in 2D and 3D cultures.
Xu, Dehui; Wang, Biqing; Xu, Yujing; Chen, Zeyu; Cui, Qinjie; Yang, Yanjie; Chen, Hailan; Kong, Michael G
2016-01-01
This study reports the potential of cold atmospheric plasma (CAP) as a versatile tool for delivering oligonucleotides into mammalian cells. Compared to lipofection and electroporation methods, plasma transfection showed a better uptake efficiency and less cell death in the transfection of oligonucleotides. We demonstrated that the level of extracellular aqueous reactive oxygen species (ROS) produced by gas plasma is correlated with the uptake efficiency and that this is achieved through an increase of intracellular ROS levels and the resulting increase in cell membrane permeability. This finding was supported by the use of ROS scavengers, which reduced CAP-based uptake efficiency. In addition, we found that cold atmospheric plasma could transfer oligonucleotides such as siRNA and miRNA into cells even in 3D cultures, thus suggesting the potential for unique applications of CAP beyond those provided by standard transfection techniques. Together, our results suggest that cold plasma might provide an efficient technique for the delivery of siRNA and miRNA in 2D and 3D culture models. PMID:27296089
Alinejad, H.; Shahmansory, M.
2012-08-15
The properties of low intensity dust ion acoustic shock waves are studied in a charge varying dusty plasma with nonextensive electrons. Owing to the departure from the Maxwellian electron distribution to a nonextensive one, the modified electrostatic charging of a spherical dust particle in plasma with ion streaming speed is considered. Based on the weakly nonlinear analysis, a new relationship between the low intensity localized disturbances and nonextensive electrons is derived. It is found that both strength and steepness of shock structures arise as the electrons evolve far from their thermodynamic equilibrium in such plasma with parameter ranges corresponding to Saturn's rings. It is also shown that the ion temperature and population of electrons reduce the possibility of the formation of the shock profile.
NASA Astrophysics Data System (ADS)
A. N., Dev; Sarma, J.; M. K., Deka; A. P., Misra; N. C., Adhikary
2014-12-01
We study the nonlinear propagation of dust-ion acoustic (DIA) shock waves in an un-magnetized dusty plasma which consists of electrons, both positive and negative ions and negatively charged immobile dust grains. Starting from a set of hydrodynamic equations with the ion thermal pressures and ion kinematic viscosities included, and using a standard reductive perturbation method, the Kadomtsev—Petviashivili—Burgers (K-P-Burgers) equation is derived, which governs the evolution of DIA shocks. A stationary solution of the K-P-Burgers equation is obtained and its properties are analysed with different plasma number densities, ion temperatures and masses. It is shown that a transition from shocks with negative potential to positive one occurs depending on the negative ion concentration in the plasma and the obliqueness of propagation of DIA waves.
NASA Astrophysics Data System (ADS)
Tsai, Ya-Yi; Tsai, Jun-Yi; I, Lin
2016-06-01
Rogue waves--rare uncertainly emerging localized events with large amplitudes--have been experimentally observed in many nonlinear wave phenomena, such as water waves, optical waves, second sound in superfluid He II (ref. ) and ion acoustic waves in plasmas. Past studies have mainly focused on one-dimensional (1D) wave behaviour through modulation instabilities, and to a lesser extent on higher-dimensional behaviour. The question whether rogue waves also exist in nonlinear 3D acoustic-type plasma waves, the kinetic origin of their formation and their correlation with surrounding 3D waveforms are unexplored fundamental issues. Here we report the direct experimental observation of dust acoustic rogue waves in dusty plasmas and construct a picture of 3D particle focusing by the surrounding tilted and ruptured wave crests, associated with the higher probability of low-amplitude holes for rogue-wave generation.
2D PIC/MC simulations of electrical asymmetry effect in capacitive coupled plasma
NASA Astrophysics Data System (ADS)
Zhang, Quan-Zhi; Jiang, Wei; Wang, You-Nian
2011-10-01
Recently a so-called electrical asymmetry effect (EAE), which could achieve high-degree separate control of ion flux and energy in dual-frequency capacitively coupled plasmas, was discovered theoretically by Heil et al. and was confirmed by experiments and theory/numerical simulations later on. However, since there always is a bigger grounded surface area for experiment devices, which reduces the geometrical symmetry, and all the simulations were limited to 1D before, it is, thus, worth studying the EAE when coupling the electrically and geometrically asymmetric discharges theoretically. Here, we perform 2D PIC/MC simulations, which can include both electrically and geometrically asymmetric factors. The EAE on plasma parameters, such as dc self-bias voltage, density profiles, ion energy distribution and power absorption of electron have been examined for different pressures and geometry conditions. Recently a so-called electrical asymmetry effect (EAE), which could achieve high-degree separate control of ion flux and energy in dual-frequency capacitively coupled plasmas, was discovered theoretically by Heil et al. and was confirmed by experiments and theory/numerical simulations later on. However, since there always is a bigger grounded surface area for experiment devices, which reduces the geometrical symmetry, and all the simulations were limited to 1D before, it is, thus, worth studying the EAE when coupling the electrically and geometrically asymmetric discharges theoretically. Here, we perform 2D PIC/MC simulations, which can include both electrically and geometrically asymmetric factors. The EAE on plasma parameters, such as dc self-bias voltage, density profiles, ion energy distribution and power absorption of electron have been examined for different pressures and geometry conditions. This work was supported by the National Natural Science Foundation of China (Grant No 10635010) and the Important National Science & Technology Specific Project (Grant No
Plasmas for environmental issues: from hydrogen production to 2D materials assembly
NASA Astrophysics Data System (ADS)
Tatarova, E.; Bundaleska, N.; Sarrette, J. Ph; Ferreira, C. M.
2014-12-01
generation in water discharges of intense UV radiation, shock waves and active radicals (OH, O, H2O2, etc), which are all effective agents against many biological pathogens and harmful chemicals, make these discharges suitable for decontamination, sterilization and purification processes. Moreover, plasmas appear as invaluable tools for the synthesis and engineering of new nanomaterials and in particular 2D materials. A brief overview on plasma-synthesized carbon nanostructures shows the high potential of such materials for energy conversion and storage applications.
Tribeche, Mouloud; Bacha, Mustapha
2013-10-15
Weak dust-acoustic waves (DAWs) are addressed in a nonthermal charge varying electronegative magnetized dusty plasmas with application to the Halley Comet. A weakly nonlinear analysis is carried out to derive a Korteweg-de Vries-Burger equation. The positive ion nonthermality, the obliqueness, and magnitude of the magnetic field are found to modify the dispersive and dissipative properties of the DA shock structure. Our results may aid to explain and interpret the nonlinear oscillations that may occur in the Halley Comet Plasma.
Structural properties of dusty plasma in direct current and radio frequency gas discharges
Ramazanov, T. S.; Dzhumagulova, K. N.; Jumabekov, A. N.; Dosbolayev, M. K.
2008-05-15
This paper presents radial distribution functions of dust particles obtained experimentally in dc and rf discharges. Pressure and interaction energy of dusty particles were calculated on the basis of these functions. The Langevin dynamics computer simulation for each experiment was performed. The comparisons with computer simulations are made.
Tasnim, I.; Mamun, A. A.; Masud, M. M.; Asaduzzaman, M.
2013-03-15
A rigorous theoretical investigation has been performed on dust-acoustic (DA) solitary structures in an unmagnetized dusty plasma, consisting of negatively charged mobile dust grains, Boltzmann distributed electrons, and nonthermally distributed ions of two distinct temperatures. The Korteweg-de Vries (K-dV), modified K-dV (mK-dV) and Gardner equations, and their solitary waves (SWs) and double layer (DL) (in case of Gardner equation) solutions are derived by using the reductive perturbation technique. The basic features of the DA Gardner solitons (GSs) and DLs are studied analytically as well as numerically. It has been observed that the GSs significantly differ from K-dV and mK-dV solitons, and only positive potential DLs exist in the system. It is also studied that two-temperature nonthermal ions significantly modify the nature and basic properties of the DA SWs. The present investigation can be very effective for understanding and studying the nonlinear characteristics of the DA waves in laboratory and space dusty plasmas.
Tsai, C.-Y.; Teng, L.-W.; Chang, M.-C.; Tseng, Y.-P.; I, Lin
2009-06-15
The Eulerian/Lagrangian dynamics in the narrow wake field of the dusty plasma bubble is explored by directly tracking dust motion at the microscopic level. The bubble is induced by the focused laser pulse ablation in three-dimensional quiescent dusty plasma liquids operated in the pressure higher than the critical pressure for the self-excitation of dust acoustic wave by the downward ion wind. It is found that, after bubble expansion ceases, the collective excitation maintains its width and travels downward as a solitary wave, led by an ultrasonic rarefaction front contributed by the dust motion below the lower boundary, and trailed by the few compressional crests with descending crest heights and speeds in the narrow wake, under the symmetry breaking by the downward ion flow. The quick damping of the waves propagating along other directions leads to a narrow wake. Increasing the background pressure causes the more isotropic collapsing of the bubble without wake field oscillation. The role played by dust motion on interacting with and sustaining the wake field evolution is identified and discussed.
NASA Astrophysics Data System (ADS)
Tsai, Chen-Yu; Teng, Lee-Wen; Chang, Mei-Chu; Tseng, Yu-Ping; I, Lin
2009-06-01
The Eulerian/Lagrangian dynamics in the narrow wake field of the dusty plasma bubble is explored by directly tracking dust motion at the microscopic level. The bubble is induced by the focused laser pulse ablation in three-dimensional quiescent dusty plasma liquids operated in the pressure higher than the critical pressure for the self-excitation of dust acoustic wave by the downward ion wind. It is found that, after bubble expansion ceases, the collective excitation maintains its width and travels downward as a solitary wave, led by an ultrasonic rarefaction front contributed by the dust motion below the lower boundary, and trailed by the few compressional crests with descending crest heights and speeds in the narrow wake, under the symmetry breaking by the downward ion flow. The quick damping of the waves propagating along other directions leads to a narrow wake. Increasing the background pressure causes the more isotropic collapsing of the bubble without wake field oscillation. The role played by dust motion on interacting with and sustaining the wake field evolution is identified and discussed.
Isotopic exchange processes in cold plasmas of H2/D2 mixtures.
Jiménez-Redondo, Miguel; Carrasco, Esther; Herrero, Víctor J; Tanarro, Isabel
2011-05-28
Isotope exchange in low pressure cold plasmas of H(2)/D(2) mixtures has been investigated by means of mass spectrometric measurements of neutrals and ions, and kinetic model calculations. The measurements, which include also electron temperatures and densities, were performed in a stainless steel hollow cathode reactor for three discharge pressures: 1, 2 and 8 Pa, and for mixture compositions ranging from 100% H(2) to 100% D(2). The data are analyzed in the light of the model calculations, which are in good global agreement with the experiments. Isotope selective effects are found both in the surface recombination and in the gas-phase ionic chemistry. The dissociation of the fuel gas molecules is followed by wall recycling, which regenerates H(2) and D(2) and produces HD. Atomic recombination at the wall is found to proceed through an Eley-Rideal mechanism, with a preference for reaction of the adsorbed atoms with gas phase D atoms. The best fit probabilities for Eley-Rideal abstraction with H and D are: γ(ER H) = 1.5 × 10(-3), γ(ER D) = 2.0 × 10(-3). Concerning ions, at 1 Pa the diatomic species H(2)(+), D(2)(+) and HD(+), formed directly by electron impact, prevail in the distributions, and at 8 Pa, the triatomic ions H(3)(+), H(2)D(+), HD(2)(+) and D(3)(+), produced primarily in reactions of diatomic ions with molecules, dominate the plasma composition. In this higher pressure regime, the formation of the mixed ions H(2)D(+) and HD(2)(+) is favoured in comparison with that of H(3)(+) and D(3)(+), as expected on statistical grounds. The model results predict a very small preference, undetectable within the precision of the measurements, for the generation of triatomic ions with a higher degree of deuteration, which is probably a residual influence at room temperature of the marked zero point energy effects (ZPE), relevant for deuterium fractionation in interstellar space. In contrast, ZPE effects are found to be decisive for the observed distribution of
Garai, S.; Banerjee, D.; Janaki, M. S.; Chakrabarti, N.
2014-02-11
In strongly coupled limit the general hydrodynamic (GH) model shows that the dusty plasma, acquiring significant rigidity, is able to support the 'shear' like mode [P. K. Kaw and A. Sen, Phys. Plasmas 5, 3552 (1998)]. In presence of velocity shear, this shear like mode is coupled with the dust acoustic mode which is generated by the compressibility effect of the dust fluid due to the finite temperature of the dust, electron and ion fluids. Local dispersion shows the velocity shear is also responsible for the instabilities of the shear mode, acoustic mode, as well as the shear-acoustic coupled mode. The present work, carried out in GH visco-elastic formalism, also gives the clear insight of the instabilities of the coupled mode in non local regime with a hyperbolic tangent velocity shear profile over a finite width.
NASA Astrophysics Data System (ADS)
Bacha, Mustapha; Tribeche, Mouloud
2016-08-01
The combined effects of an oblique magnetic field and electron trapping on dissipative dust-acoustic waves are examined in varying charge electronegative dusty plasmas with application to the Halley Comet plasma (˜104 km from the nucleus). A weakly nonlinear analysis is carried out to derive a modified Korteweg-de Vries-Burger-like equation. Making use of the equilibrium current balance equation, the physically admissible values of the electron trapping parameter are first constrained. We then show that the Burger dissipative term is solely due to the dust charge variation process. It is found that an increase of the magnetic field obliqueness or a decrease of its magnitude renders the shock structure more dispersive.
NASA Astrophysics Data System (ADS)
Garai, S.; Janaki, M. S.; Chakrabarti, N.
2016-09-01
The nonlinear propagation of low frequency waves, in a collisionless, strongly coupled dusty plasma (SCDP) with a density dependent viscosity, has been studied with a proper Galilean invariant generalized hydrodynamic (GH) model. The well known reductive perturbation technique (RPT) has been employed in obtaining the solutions of the longitudinal and transverse perturbations. It has been found that the nonlinear propagation of the acoustic perturbations govern with the modified Korteweg-de Vries (KdV) equation and are decoupled from the sheared fluctuations. In the regions, where transversal gradients of the flow exists, coupling between the longitudinal and transverse perturbations occurs due to convective nonlinearity which is true for the homogeneous case also. The results, obtained here, can have relative significance to astrophysical context as well as in laboratory plasmas.
Asaduzzaman, M; Mamun, A A
2012-07-01
A rigorous theoretical investigation has been made of the effects of nonthermal ions and polarization force (which arises due to the dust density inhomogeneity) on the propagation of dust-acoustic (DA) waves in a density-varying unmagnetized dusty plasma (consisting of nonthermal ions, Maxwellian electrons, and negatively charged mobile dust) by the normal mode analysis. It has been shown that the dispersion properties of the DA waves are significantly modified by the presence of nonthermal ions and polarization force. It has been also found that the phase speed of the DA waves, as well as the dust density perturbation, increases (decreases) with the increase of nonthermal ions (polarization force), and that the potential associated with the DA waves decreases with the increase of the equilibrium dust number density. The implications of our results in the specific situation of space environments (dust-ion plasma situation) are also briefly discussed. PMID:23005552
NASA Astrophysics Data System (ADS)
Lee, Myoung-Jae; Jung, Young-Dae
2016-03-01
The dispersion relation for the dust ion-acoustic surface waves propagating at the interface of semi-bounded Lorentzian dusty plasma with supersonic ion flow has been kinetically derived to investigate the nonthermal property and the ion wake field effect. We found that the supersonic ion flow creates the upper and the lower modes. The increase in the nonthermal particles decreases the wave frequency for the upper mode whereas it increases the frequency for the lower mode. The increase in the supersonic ion flow velocity is found to enhance the wave frequency for both modes. We also found that the increase in nonthermal plasmas is found to enhance the group velocity of the upper mode. However, the nonthermal particles suppress the lower mode group velocity. The nonthermal effects on the group velocity will be reduced in the limit of small or large wavelength limit.
2D surface temperature measurement of plasma facing components with modulated active pyrometry
Amiel, S.; Loarer, T.; Pocheau, C.; Roche, H.; Gauthier, E.; Aumeunier, M.-H.; Courtois, X.; Jouve, M.; Balorin, C.; Moncada, V.; Le Niliot, C.; Rigollet, F.
2014-10-01
In nuclear fusion devices, such as Tore Supra, the plasma facing components (PFC) are in carbon. Such components are exposed to very high heat flux and the surface temperature measurement is mandatory for the safety of the device and also for efficient plasma scenario development. Besides this measurement is essential to evaluate these heat fluxes for a better knowledge of the physics of plasma-wall interaction, it is also required to monitor the fatigue of PFCs. Infrared system (IR) is used to manage to measure surface temperature in real time. For carbon PFCs, the emissivity is high and known (ε ~ 0.8), therefore the contribution of the reflected flux from environment and collected by the IR cameras can be neglected. However, the future tokamaks such as WEST and ITER will be equipped with PFCs in metal (W and Be/W, respectively) with low and variable emissivities (ε ~ 0.1–0.4). Consequently, the reflected flux will contribute significantly in the collected flux by IR camera. The modulated active pyrometry, using a bicolor camera, proposed in this paper allows a 2D surface temperature measurement independently of the reflected fluxes and the emissivity. Experimental results with Tungsten sample are reported and compared with simultaneous measurement performed with classical pyrometry (monochromatic and bichromatic) with and without reflective flux demonstrating the efficiency of this method for surface temperature measurement independently of the reflected flux and the emissivity.
Multichannel reconfigurable measurement system for hot plasma diagnostics based on GEM-2D detector
NASA Astrophysics Data System (ADS)
Wojenski, A. J.; Kasprowicz, G.; Pozniak, K. T.; Byszuk, A.; Chernyshova, M.; Czarski, T.; Jablonski, S.; Juszczyk, B.; Zienkiewicz, P.
2015-12-01
In the future magnetically confined fusion research reactors (e.g. ITER tokamak), precise determination of the level of the soft X-ray radiation of plasma with temperature above 30 keV (around 350 mln K) will be very important in plasma parameters optimization. This paper presents the first version of a designed spectrography measurement system. The system is already installed at JET tokamak. Based on the experience gained from the project, the new generation of hardware for spectrography measurements, was designed and also described in the paper. The GEM detector readout structure was changed to 2D in order to perform measurements of i.e. laser generated plasma. The hardware structure of the system was redesigned in order to provide large number of high speed input channels. Finally, this paper also covers the issue of new control software, necessary to set-up a complete system of certain complexity and perform data acquisition. The main goal of the project was to develop a new version of the system, which includes upgraded structure and data transmission infrastructure (i.e. handling large number of measurement channels, high sampling rate).
2D surface temperature measurement of plasma facing components with modulated active pyrometry
NASA Astrophysics Data System (ADS)
Amiel, S.; Loarer, T.; Pocheau, C.; Roche, H.; Gauthier, E.; Aumeunier, M.-H.; Le Niliot, C.; Rigollet, F.; Courtois, X.; Jouve, M.; Balorin, C.; Moncada, V.
2014-10-01
In nuclear fusion devices, such as Tore Supra, the plasma facing components (PFC) are in carbon. Such components are exposed to very high heat flux and the surface temperature measurement is mandatory for the safety of the device and also for efficient plasma scenario development. Besides this measurement is essential to evaluate these heat fluxes for a better knowledge of the physics of plasma-wall interaction, it is also required to monitor the fatigue of PFCs. Infrared system (IR) is used to manage to measure surface temperature in real time. For carbon PFCs, the emissivity is high and known (ɛ ˜ 0.8), therefore the contribution of the reflected flux from environment and collected by the IR cameras can be neglected. However, the future tokamaks such as WEST and ITER will be equipped with PFCs in metal (W and Be/W, respectively) with low and variable emissivities (ɛ ˜ 0.1-0.4). Consequently, the reflected flux will contribute significantly in the collected flux by IR camera. The modulated active pyrometry, using a bicolor camera, proposed in this paper allows a 2D surface temperature measurement independently of the reflected fluxes and the emissivity. Experimental results with Tungsten sample are reported and compared with simultaneous measurement performed with classical pyrometry (monochromatic and bichromatic) with and without reflective flux demonstrating the efficiency of this method for surface temperature measurement independently of the reflected flux and the emissivity.
Liver/kidney microsomal antibody type 1 targets CYP2D6 on hepatocyte plasma membrane
Muratori, L; Parola, M; Ripalti, A; Robino, G; Muratori, P; Bellomo, G; Carini, R; Lenzi, M; Landini, M; Albano, E; Bianchi, F
2000-01-01
BACKGROUND—Liver/kidney microsomal antibody type 1 (LKM1) is the marker of type 2 autoimmune hepatitis (AIH) and is detected in up to 6% of patients with hepatitis C virus (HCV) infection. It recognises linear and conformational epitopes of cytochrome P450IID6 (CYP2D6) and may have liver damaging activity, provided that CYP2D6 is accessible to effector mechanisms of autoimmune attack. METHODS—The presence of LKM1 in the plasma membrane was investigated by indirect immunofluorescence and confocal laser microscopy of isolated rat hepatocytes probed with 10 LKM1 positive sera (five from patients with AIH and five from patients with chronic HCV infection) and a rabbit polyclonal anti-CYP2D6 serum. RESULTS—Serum from both types of patient stained the plasma membrane of non-permeabilised cells, where the fluorescent signal could be visualised as discrete clumps. Conversely, permeabilised hepatocytes showed diffuse submembranous/cytoplasmic staining. Adsorption with recombinant CYP2D6 substantially reduced plasma membrane staining and LKM1 immunoblot reactivity. Plasma membrane staining of LKM1 colocalised with that of anti-CYP2D6. Immunoprecipitation experiments showed that a single 50 kDa protein recognised by anti-CYP2D6 can be isolated from the plasma membrane of intact hepatocytes. CONCLUSIONS—AIH and HCV related LKM1 recognise CYP2D6 exposed on the plasma membrane of isolated hepatocytes. This observation supports the notion that anti-CYP2D6 autoreactivity may be involved in the pathogenesis of liver damage. Keywords: liver/kidney microsomal antibody type 1; autoimmunity; autoimmune hepatitis; hepatitis C virus infection; confocal microscopy PMID:10716687
Numerical Study of Microwave Reflectometry in Plasmas with 2D Turbulent Fluctuations
E. Mazzucato
1998-02-01
This paper describes a numerical study of the role played by 2D turbulent fluctuations in microwave reflectometry -- a radar technique for density measurements using the reflection of electromagnetic waves from a plasma cutoff. The results indicate that, if the amplitude of fluctuations is below a threshold which is set by the spectrum of poloidal wavenumbers, the measured backward field appears to originate from a virtual location behind the reflecting layer, and to arise from the phase modulation of the probing wave, with an amplitude given by 1D geometric optics. These results suggest a possible scheme for turbulence measurements in tokamaks, where the backward field is collected with a wide aperture antenna, and the virtual reflecting layer is imaged onto the plane of an array of detectors. Such a scheme should be capable of providing additional information on the nature of the short-scale turbulence observed in tokamaks, which still remains one of the unresolved issues in fusion research.
Paul, A.; Mandal, G.; Amin, M. R.; Mamun, A. A.
2013-10-15
The nonlinear propagation of dust-acoustic (DA) waves in an unmagnetized dusty plasma consisting of nonthermal electrons, vortex-like (trapped) distributed ions and mobile negative dust have been investigated by employing the reductive perturbation technique. The effects of nonthermal electrons and trapped ions are found to modify the properties of the DA solitary waves.
Development of 2D imaging of SXR plasma radiation by means of GEM detectors
NASA Astrophysics Data System (ADS)
Chernyshova, M.; Czarski, T.; Jabłoński, S.; Kowalska-Strzeciwilk, E.; Poźniak, K.; Kasprowicz, G.; Zabołotny, W.; Wojeński, A.; Byszuk, A.; Burza, M.; Juszczyk, B.; Zienkiewicz, P.
2014-11-01
Presented 2D gaseous detector system has been developed and designed to provide energy resolved fast dynamic plasma radiation imaging in the soft X-Ray region with 0.1 kHz exposure frequency for online, made in real time, data acquisition (DAQ) mode. The detection structure is based on triple Gas Electron Multiplier (GEM) amplification structure followed by the pixel readout electrode. The efficiency of detecting unit was adjusted for the radiation energy region of tungsten in high-temperature plasma, the main candidate for the plasma facing material for future thermonuclear reactors. Here we present preliminary laboratory results and detector parameters obtained for the developed system. The operational characteristics and conditions of the detector were designed to work in the X-Ray range of 2-17 keV. The detector linearity was checked using the fluorescence lines of different elements and was found to be sufficient for good photon energy reconstruction. Images of two sources through various screens were performed with an X-Ray laboratory source and 55Fe source showing a good imaging capability. Finally offline stream-handling data acquisition mode has been developed for the detecting system with timing down to the ADC sampling frequency rate (~13 ns), up to 2.5 MHz of exposure frequency, which could pave the way to invaluable physics information about plasma dynamics due to very good time resolving ability. Here we present results of studied spatial resolution and imaging properties of the detector for conditions of laboratory moderate counting rates and high gain.
Thermochemical Nonequilibrium 2D Modeling of Nitrogen Inductively Coupled Plasma Flow
NASA Astrophysics Data System (ADS)
Yu, Minghao; Yusuke, Takahashi; Hisashi, Kihara; Ken-ichi, Abe; Kazuhiko, Yamada; Takashi, Abe; Satoshi, Miyatani
2015-09-01
Two-dimensional (2D) numerical simulations of thermochemical nonequilibrium inductively coupled plasma (ICP) flows inside a 10-kW inductively coupled plasma wind tunnel (ICPWT) were carried out with nitrogen as the working gas. Compressible axisymmetric Navier-Stokes (N-S) equations coupled with magnetic vector potential equations were solved. A four-temperature model including an improved electron-vibration relaxation time was used to model the internal energy exchange between electron and heavy particles. The third-order accuracy electron transport properties (3rd AETP) were applied to the simulations. A hybrid chemical kinetic model was adopted to model the chemical nonequilibrium process. The flow characteristics such as thermal nonequilibrium, inductive discharge, effects of Lorentz force were made clear through the present study. It was clarified that the thermal nonequilibrium model played an important role in properly predicting the temperature field. The prediction accuracy can be improved by applying the 3rd AETP to the simulation for this ICPWT. supported by Grant-in-Aid for Scientific Research (No. 23560954), sponsored by the Japan Society for the Promotion of Science
2D electrostatic PIC algorithm for laser induced studying plasma in vacuum
NASA Astrophysics Data System (ADS)
Álvarez, C. A.; Riascos, H.; Gonzalez, C.
2016-02-01
Particle-In-Cell(PIC) method is widely used for simulating plasma kinetic models. A 2D-PIC electrostatic algorithm is implemented for simulating the expansion of a laser- induced plasma plume. For potential and Electric Field calculation, Dirichlet and periodic boundary conditions are used in the X (perpendicular to the ablated material) and Y directions, respectively. Poisson-solver employs FFTW3 library and the five-point Laplacian to compute the electric potential. Electric field calculation is made by central finite differences method. Leap-frog scheme updates particle positions and velocities at each iteration. Plume expansion anlysis is done for the Emission and Post-Emission stages. In the Emission phase (while the laser is turned on), fast electron expansion is observed and ion particles remain near the surface of the ablated material. In the post-emission stage (with the laser turned off) the charge separation produces an electric field that accelerates the ions leading to the formation of a KeV per particle Ion-Front. At the end of the expansion, fastest electrons escape from the simulation space; an almost homogeneous ion-electron distribution is observed, decreasing the electric field value and the Coulomb interactions.
NASA Astrophysics Data System (ADS)
Wang, Yunliang; Guo, Xiaoyan; Lu, Yanzhen; Wang, Xiaodan
2016-01-01
The combined effects of nonadiabatic dust charge fluctuation and strongly coupled dust particles on the nonlinear propagation of dust acoustic (DA) waves in dusty plasma consisting of nonthermal electrons and trapped ions with vortex-like distribution are presented here. We use generalized viscoelastic hydrodynamic model for dust particles. In the weak nonlinearity limit, a modified Korteweg-de Vries (KdV) equation with a damping term and a KdV-Burger equation have been derived in the kinetic regime and hydrodynamic regime, respectively. The approximate analytical solitary solution of modified KdV equation is derived in the weak nonadiabatic dust charge variation limit, which shows that the amplitude of DA solitary waves decreases with time. The presence of viscosity due to strong coupling stands for the formation of DA shock waves in the hydrodynamic regime. The results show that the DA shock waves will be oscillating one for weak viscosity and will become monotonic ones for large viscosity.
Singh Gill, Tarsem; Bedi, Chanchal; Saini, Nareshpal Singh
2011-04-15
The higher order solutions of dust acoustic wave in dusty plasma consisting of positively charged warm adiabatic dust, negatively charged cold dust, and nonisothermally distributed electrons are studied. The Schamel-KdV equation is derived using reductive perturbation method (RPM). RPM is further extended to include the contributions of higher order terms and a generalized KdV equation is derived to observe the deviation from isothermality. Effects of nonisothermal parameter, mass and charge ratio, ratio of ion to electron temperatures, and ratio of dust to ion temperatures have been thoroughly studied. By using the renormalization method of Kodama and Taniuti [J. Phys. Soc. Jpn. 45, 298 (1978)], authors have also discussed characteristics of the dressed solitons.
El-Labany, S.K.; El-Shamy, E.F.
2005-04-15
The nonlinear properties of solitary waves structures in a hot magnetized dusty plasma consisting of isothermal hot electrons, nonisothermal ions, and high negatively charged massive dust grains are reported. A modified Korteweg-de Vries (modified KdV) equation, which admits a solitary waves solution, for small but finite amplitude, is derived using a reductive perturbation theory. A nonisothermal ion distribution provides the possibility of existence of rarefactive solitary waves. On the other hand, the dynamics of solitary waves at a critical ion density is governed by KdV equation. The modification in the amplitude and width of the solitary waves structures due to the inclusion of obliqueness and external magnetic field are also investigated.
The collision effect between dust grains and ions to the dust ion acoustic waves in a dusty plasma
Yang Xue; Wang Canglong; Liu Congbo; Zhang Jianrong; Shi Yuren; Duan Wenshan; Yang Lei
2012-10-15
Damping solitary wave in dusty plasma is studied by considering the collision effect between dust grains and ions. It can be described by a KdV type equation in which a damping term of {phi}{sup 2} exist. It is found that both the amplitude and propagation velocity of the solitary wave decrease with time exponentially. Our results are compared with another KdV type equation with the damping term of {phi}. It is noted that the damping rate of the KdV type equation with the damping term of {phi}{sup 2} is larger than that with the term of {phi}. It is found that the damping rate is proportional to the collision frequency between dust grains and ions.
Arbitrary amplitude dust ion-acoustic shock waves in a dusty plasma with positive and negative ions
Mamun, A. A.; Shukla, P. K.; Eliasson, B.
2009-11-15
Arbitrary amplitude dust ion-acoustic shock waves in a multi-ion dusty plasma (composed of electrons, light positive ions, heavy negative ions, and stationary massive dust grains) has been studied. For this purpose, the coupled Poisson and dust-charging equations, which accounts for the fluctuation of charges on static dust, have been numerically solved. The large amplitude shocks are associated with a sudden decrease in the electrostatic potential and of the dust grain charge. It is found that in the lower speed limit small amplitude shocks are formed, while in the larger speed limit large amplitude shocks are formed. It is anticipated that the profiles and amplitudes of the DIA shocks predicted here will be observed in forthcoming laboratory and space experiments.
NASA Astrophysics Data System (ADS)
Zhou, Shengguo; Li, Hailong; Fu, Luyao; Wang, Maoyan
2016-06-01
Radar echoes intensity of polar mesosphere summer echoes (PMSE) is greatly affected by the temperature of dusty plasma and the frequency of electromagnetic wave about the radar. In this paper, a new method is developed to explain the active experiment results of PMSE. The theory of wave propagation in a layered media is used to study the propagation characteristics of an electromagnetic wave at different electron temperatures. The simulation results show that the variation tendency of the reflected power fraction almost agrees with the results observed by radar in the European Incoherent Scatter Scientific Association (EISCAT). The radar echoes intensity of PMSE greatly decreases with the increase of the radio frequency and the enhancement of the electron temperature. supported by National Natural Science Foundation of China (Nos. 41104097 and 41304119) and by the National Key Laboratory of Electromagnetic Environment, China Research Institute of Radiowave Propagation (CRIRP)
El-Hanbaly, A. M.; Sallah, M.; El-Shewy, E. K.; Darweesh, H. F.
2015-10-15
Linear and nonlinear dust-acoustic (DA) waves are studied in a collisionless, unmagnetized and dissipative dusty plasma consisting of negatively charged dust grains, Boltzmann-distributed electrons, and nonthermal ions. The normal mode analysis is used to obtain a linear dispersion relation illustrating the dependence of the wave damping rate on the carrier wave number, the dust viscosity coefficient, the ratio of the ion temperature to the electron temperatures, and the nonthermal parameter. The plasma system is analyzed nonlinearly via the reductive perturbation method that gives the KdV-Burgers equation. Some interesting physical solutions are obtained to study the nonlinear waves. These solutions are related to soliton, a combination between a shock and a soliton, and monotonic and oscillatory shock waves. Their behaviors are illustrated and shown graphically. The characteristics of the DA solitary and shock waves are significantly modified by the presence of nonthermal (fast) ions, the ratio of the ion temperature to the electron temperature, and the dust kinematic viscosity. The topology of the phase portrait and the potential diagram of the KdV-Burgers equation is illustrated, whose advantage is the ability to predict different classes of traveling wave solutions according to different phase orbits. The energy of the soliton wave and the electric field are calculated. The results in this paper can be generalized to analyze the nature of plasma waves in both space and laboratory plasma systems.
NASA Astrophysics Data System (ADS)
El-Hanbaly, A. M.; Sallah, M.; El-Shewy, E. K.; Darweesh, H. F.
2015-10-01
Linear and nonlinear dust-acoustic (DA) waves are studied in a collisionless, unmagnetized and dissipative dusty plasma consisting of negatively charged dust grains, Boltzmann-distributed electrons, and nonthermal ions. The normal mode analysis is used to obtain a linear dispersion relation illustrating the dependence of the wave damping rate on the carrier wave number, the dust viscosity coefficient, the ratio of the ion temperature to the electron temperatures, and the nonthermal parameter. The plasma system is analyzed nonlinearly via the reductive perturbation method that gives the KdV-Burgers equation. Some interesting physical solutions are obtained to study the nonlinear waves. These solutions are related to soliton, a combination between a shock and a soliton, and monotonic and oscillatory shock waves. Their behaviors are illustrated and shown graphically. The characteristics of the DA solitary and shock waves are significantly modified by the presence of nonthermal (fast) ions, the ratio of the ion temperature to the electron temperature, and the dust kinematic viscosity. The topology of the phase portrait and the potential diagram of the KdV-Burgers equation is illustrated, whose advantage is the ability to predict different classes of traveling wave solutions according to different phase orbits. The energy of the soliton wave and the electric field are calculated. The results in this paper can be generalized to analyze the nature of plasma waves in both space and laboratory plasma systems.
Atamaniuk, Barbara; Zuchowski, Krzysztof
2006-01-15
There is a quickly increasing wealth of experimental data on so-called dusty plasmas i. e. ionized gases or usual plasmas that contain micron sized charged particles. Interest in these structures is driven both by their importance in many astrophysical as well as commercial situations. Among them are linear and nonlinear wave phenomena. We consider the influence of dust charge fluctuations on stability of the ion-acoustic waves when the stream of particles is present. It is assumed that all grains of dust have equal masses but charges are not constant in time-they may fluctuate in time. The dust charges are not really independent of the variations of the plasma potentials. All modes will influence the charging mechanism, and feedback will lead to several new interesting and unexpected phenomena. The charging of the grains depends on local plasma characteristics. If the waves disturb these characteristic, then charging of the grains is affected and the grain charge is modified, with a resulting feedback on the wave mode. In case considering here, when temperature of electrons is much greater then the temperature of the ions and temperature of electrons is not great enough for further ionization of the ions, we show that stability of the acoustic wave depends only one phenomenological coefficient.
NASA Astrophysics Data System (ADS)
Sabetkar, Akbar; Dorranian, Davoud
2015-08-01
In this paper, our attention is first concentrated on obliquely propagating properties of low-frequency (ω ≪ ωcd) "fast" and "slow" dust acoustic waves, in the linear regime, in dusty electronegative plasmas with Maxwellian electrons, kappa distributed positive ions, negative ions (following the combination of kappa-Schamel distribution), and negatively charged dust particles. So, an explicit expression for dispersion relation is derived by linearizing a set of dust-fluid equations. The results show that wave frequency ω in long and short-wavelengths limit is conspicuously affected by physical parameters, namely, positive to negative temperature ion ratio (βp), trapping parameter of negative ions (μ), magnitude of the magnetic field B0 (via ωcd), superthermal index ( κn,κp ), and positive ion to dust density ratio (δp). The signature of the penultimate parameter (i.e., κn) on wave frequency reveals that the frequency gap between the modes reduces (escalates) for k
Gradient-Driven Vortex Motion in Nonneutral Plasmas and Ideal 2D Fluids
NASA Astrophysics Data System (ADS)
Schecter, David A.
2000-10-01
Two-dimensional (2D) turbulent flows can relax to metastable patterns without dissipation of kinetic energy. This ``rapid'' relaxation has been observed in computer simulations of ideal 2D fluids, and more recently in experiments with pure electron plasmas, which can obey similar dynamics. The late stage of relaxation often involves small vortices moving in a larger ``background'' shear-flow.(X.P. Huang et al., Phys. Rev. Lett. 74), 4424 (1995). In time, positive vortices (rotating counter-clockwise) move to peaks in background vorticity, whereas negative vortices (rotating clockwise) move to minima.(C.G. Rossby, J. Mar. Res. 7), 175 (1948); C.H. Liu and L. Ting, Comp. & Fluids 15, 77 (1987). In general, the rate of this migration increases with the magnitude of the background vorticity gradient, whereas it decreases as the background shear intensifies.\\vspace12pt Positive and negative vortices can also be classified as either prograde or retrograde, depending on whether they rotate with or against the local background shear. Surprisingly, a retrograde vortex moves up or down a background vorticity gradient orders of magnitude faster than a prograde vortex of equal strength.(D.A. Schecter and D.H.E. Dubin, Phys. Rev. Lett. 83), 2191 (1999). An accurate expression for the velocity of a weak retrograde vortex is obtained from an analytic calculation, in which the response of the background flow to the vortex is linearized. However, this linear theory fails for prograde vortices of any strength. Interestingly, the velocity of a prograde vortex can be obtained from a simple estimate, which accounts for the nonlinear ``trapping'' of background fluid around the vortex. The analytic expressions for the velocities of both prograde and retrograde vortices are in good quantitative agreement with vortex-in-cell simulations, and with electron plasma experiments, when the background shear is below a critical level. When the ratio of background shear to background vorticity
Stochastic simulation of thermoemission from surfaces of dusty grains
NASA Astrophysics Data System (ADS)
Bondareva, A. L.; Levchenko, V. D.; Zmievskaya, G. I.
2005-05-01
The thermoemission from dusty grains surfaces is necessary to take into account when processes in dusty plasma are simulated. The thermoemission of electrons can change temperature of electron part of plasma, typical electron velocity and others plasma properties. The kinetic distribution functions of secondary electrons from velocity and distance from dusty grain are calculated.
Comprehensive 2D measurements of radiative divertor plasmas in DIII-D
Fenstermacher, M.E.; Wood, R.D.; Allen, S.L.; Hill, D.N.
1997-07-01
This paper presents a comparison of the total radiated power profile and impurity line emission distributions in the SOL and divertor of DIII-D. This is done for ELMing H-mode plasmas with heavy deuterium injection (Partially Detached Divertor operation, PDD) and those without deuterium puffing. Results are described from a series of dedicated experiments performed on DIII-D to systematically measure the 2-D (R,Z) structure of the divertor plasma. The discharges were designed to optimize measurements with new divertor diagnostics including a divertor Thomson scattering system. Discharge sequences were designed to produce optimized data sets against which SOL and divertor theories and simulation codes could be benchmarked. During PDD operation the regions of significant radiated power shift from the inner divertor leg and SOL to the outer leg and X-point regions. D{alpha} emission shifts from the inner strikepoint to the outer strikepoint. Carbon emissions (visible CII and CIII) shift from the inner SOL near the X-point to a distributed region from the X-point to partially down the outer leg during moderate D2 puffing. In heavy puffing discharges the carbon emission coalesces on the outer separatrix near the X-point and for very heavy puffing it appears inside the last closed flux surface above the X-point. Calibrated spectroscopic measurements indicate that hydrogenic and carbon radiation can account for all of the radiated power. L{alpha} and CIV radiation are comparable and when combined account for as much as 90% of the total radiated power along chords viewing the significant radiating regions of the outer leg.
NASA Astrophysics Data System (ADS)
El-Labany, S. K.; El-Taibany, W. F.; Behery, E. E.; Zedan, N. A.
2015-12-01
Propagation of dust acoustic solitary waves (DASWs) in a magnetized dusty plasma consisting of extremely massive, negatively/positively charged dust fluid and Boltzmann distributed electrons and ions is studied. A nonlinear Zakharov-Kuznetsov (ZK) equation adequate for describing the solitary waves is derived by applying a reductive perturbation technique. Moreover, an extended Zakharov Kuznetsov (EZK) equation is derived at the vicinity of the critical phase velocity. The effects of the polarization force are explicitly discussed and the growth rate of the produced waves is calculated. It is found that the physical parameters have strong effects on the instability criterion as well as on the growth rate. It is noted that the phase velocity decreases as the polarization force, the effective-to-ion temperature ratio, and the ion-to-electron temperature ratio increase. Moreover, the nonlinearity coefficient and the critical phase velocity increase by increasing the polarization force. The relevance of these findings to a recent plasma experiment and astrophysical plasma observations is briefly discussed.
El-Taibany, W. F.
2013-09-15
The reductive perturbation technique is employed to investigate the propagation properties of nonlinear dust acoustic (DA) waves in a four-component inhomogeneous dusty plasma (4CIDP). The 4CIDP consists of both positive- and negative-charge dust grains, characterized by different mass, temperature, and density, in addition to a background of Maxwellian electrons and ions. The inhomogeneity caused by nonuniform equilibrium values of particle densities, fluid velocities, and electrostatic potential leads to a significant modification to the nature of nonlinear DA solitary waves. It is found that this model reveals two DA wave velocities, one slow, λ{sub s}, and the other is fast, λ{sub f}. The nonlinear wave evolution is governed by a modified Kortweg-de Vries equation, whose coefficients are space dependent. Both the two soliton types; compressive and rarefactive are allowed corresponding to λ{sub s}. However, only compressive soliton is created corresponding to λ{sub f}. The numerical investigations illustrate the dependence of the soliton amplitude, width, and velocity on the plasma inhomogeneities in each case. The relevance of these theoretical results with 4CIDPs observed in a multi-component plasma configurations in the polar mesosphere is discussed.
NASA Astrophysics Data System (ADS)
Tribeche, Mouloud; Mayout, Saliha
2016-07-01
The combined effects of ionization, ion loss and electron suprathermality on dust ion- acoustic solitary waves in a collisional dusty plasma are examined. Carrying out a small but finite amplitude analysis, a damped Korteweg- de Vries (dK-- dV) equation is derived. The damping term decreases with the increase of the spectral index and saturates for Maxwellian electrons. Choosing typical plasma parameters, the analytical approximate solution of the dK- dV equation is numerically analyzed. We first neglect the ionization and ion loss effects and account only for collisions to estimate the relative importance between these damping terms which can act concurrently. Interestingly, we found that as the suprathermal character of the electrons becomes important, the strength of the collisions related dissipation becomes more important and causes the DIA solitary wave amplitude to decay more rapidly. Moreover, the collisional damping may largely prevail over the ionization and ion loss related damping. The latter becomes more effective as the electrons evolve far away from their thermal equilibrium. Our results complement and provide new insights into previously published work on this problem.
Sarkar, Sanjib; Bose, M.; Pramanik, J.; Mukherjee, S.
2013-02-15
We have experimentally observed the behaviour of cogenerated dusts in unmagnetized plasma produced using a bipolar pulsed dc power supply. In this experiment, the dust particles have been generated through sputtering of graphite cathode and were stratified between two electrodes. This stratification of dust clouds has obtained at a typical range of plasma parameters, namely, 650 V (peak-to-peak) with 0.2 mbar pressure. In above condition, we detected the Taylor-like instability at the interface of two dusty clouds with different densities. A very less dust density (void like) region inside the lesser dust density portion is also noted. Again, it has been observed that a self excited dust density wave propagates towards the higher density dust fluid inside the system as well as a stationary band structure of thin multiple layers of dust particles when we apply a higher voltage (750 V peak-to-peak). The wavelength, phase velocity, and frequency of the excited wave have also been estimated.
Shahmohammadi, Nafise; Dorranian, Davoud
2015-10-15
Simultaneous effects of dust charge fluctuation and nonthermal ions on the threshold point and growth rate of three-dimensional instability of dust-acoustic solitary waves (DASW) in magnetized dusty plasma have been investigated. In this model, dusty plasma consists of Maxwellian electrons, nonthermal ions, and micron size negatively charged dust particles. Modified Zakharov-Kuznetsov equation for DASW was derived employing a reductive perturbation method and its solitary answer under the influence of dust charge fluctuation and nonthermal ions has been studied. The dispersion relation of DASW has been derived using a small-k perturbation method. Results show that the direction and the magnitude of external magnetic field at which the instability takes place are strongly affected by the rate of dust charge fluctuation and nonthermality of ions. With increasing the number of nonthermal ions, the growth rate of instability decreases, while increasing the dust charge fluctuation increases the growth rate of instability.
NASA Astrophysics Data System (ADS)
Hadjaz, Idir; Tribeche, Mouloud
2014-06-01
Alternative localized dust-ion acoustic waves are investigated in a magnetized charge varying dusty plasma with nonthermal electrons having a vortex-like velocity distribution. The correct non-Maxwellian charging currents are obtained based on the well-known orbit limited motion theory. Following the standard reductive perturbation technique, a Schamel-Zakharov Kuznetsov Burgers (S-ZKB) equation is derived. It is shown that due to an interplay between trapping and nonthermality, our dusty plasma model may support solitary as well as shock waves the main quantities (phase velocity, amplitude and width) of which are drastically influenced by trapping, nonthermality and charge variation. Due to the flexibility provided by the outlined distribution function (two concepts of non isothermality), we stress that our model should provide a good fit of the space observations.
NASA Astrophysics Data System (ADS)
Shahmohammadi, Nafise; Dorranian, Davoud
2015-10-01
Simultaneous effects of dust charge fluctuation and nonthermal ions on the threshold point and growth rate of three-dimensional instability of dust-acoustic solitary waves (DASW) in magnetized dusty plasma have been investigated. In this model, dusty plasma consists of Maxwellian electrons, nonthermal ions, and micron size negatively charged dust particles. Modified Zakharov-Kuznetsov equation for DASW was derived employing a reductive perturbation method and its solitary answer under the influence of dust charge fluctuation and nonthermal ions has been studied. The dispersion relation of DASW has been derived using a small-k perturbation method. Results show that the direction and the magnitude of external magnetic field at which the instability takes place are strongly affected by the rate of dust charge fluctuation and nonthermality of ions. With increasing the number of nonthermal ions, the growth rate of instability decreases, while increasing the dust charge fluctuation increases the growth rate of instability.
Maitra, Sarit; Roychoudhury, Rajkumar
2005-05-15
Sagdeev's technique is used to study the dust ion-acoustic solitary waves (DIASWs) in a dusty plasma comprising ions, electrons, and charged dust grains taking into account the ion kinematic viscosity. Exact analytical results for the solitary wave solutions were obtained for small amplitude DIASW. The effects of the ion kinematic viscosity and the ion temperature on the feature of DIASW have been investigated.
2D and 3D PIC-MCC simulations of a low temperature magnetized plasma on CPU and GPU
NASA Astrophysics Data System (ADS)
Claustre, Jonathan; Chaudhury, Bhaskar; Fubiani, Gwenael; Boeuf, Jean-Pierre
2012-10-01
A Particle-In-Cell Monte Carlo Collisions model is used to described plasma transport in a low temperature magnetized plasma under conditions similar to those of the negative ion source for the neutral beam injector of ITER. A large diamagnetic electron current is present in the plasma because of the electron pressure gradient between the ICP driver of the source and the entrance of the magnetic filter, and is directed toward the chamber walls. The plasma potential adjusts to limit the diamagnetic electron current to the wall, leading to large electron current flow through the filter, and to a non uniform plasma density in the region between magnetic filter and extracting grids. On the basis of the PIC-MCC simulation results, we describe the plasma properties and electron current density distributions through the filter in 2D and 3D situations and use these models to better understand plasma transport across the filter in these conditions. We also present comparisons between computation times of two PIC-MCC simulation codes that have been developed for operations on standard CPU (Central Processing Units, code in Fortran) and on GPU (Graphics Processing Units, code in CUDA). The results show that the GPU simulation is about 25 times faster than the CPU one for a 2D domain with 512x512 grid points. The computation time ratio increases with the number of grid points.
Effective Semi-empirical Interaction Potential for Dusty Particles
Ramazanov, T. S.; Dzhumagulova, K. N.; Omarbakiyeva, Y. A.; Dosbolayev, M. K.; Jumabekov, A. N.
2008-09-07
The Poisson equation was numerically solved on the basis of the experimental correlation functions of dusty particles. Calculations were performed with real parameters of dusty plasma. Reconstructed potential has oscillated character; the minimums coincide to maximums of correlation functions.
Dusty Plasma Modeling of the Fusion Reactor Sheath Including Collisional-Radiative Effects
Dezairi, Aouatif; Samir, Mhamed; Eddahby, Mohamed; Saifaoui, Dennoun; Katsonis, Konstantinos; Berenguer, Chloe
2008-09-07
The structure and the behavior of the sheath in Tokamak collisional plasmas has been studied. The sheath is modeled taking into account the presence of the dust{sup 2} and the effects of the charged particle collisions and radiative processes. The latter may allow for optical diagnostics of the plasma.
Mowafy, A. E.; El-Shewy, E. K.; Zahran, M. A.; Moslem, W. M.
2008-07-15
Investigation of positive and negative dust charge fluctuations on the propagation of dust-ion acoustic waves (DIAWs) in a weakly inhomogeneous, collisionless, unmagnetized dusty plasmas consisting of cold positive ions, stationary positively and negatively charged dust particles and isothermal electrons. The reductive perturbation method is employed to reduce the basic set of fluid equations to the variable coefficients Korteweg-de Varies (KdV) equation. At the critical ion density, the KdV equation is not appropriate for describing the system. Hence, a new set of stretched coordinates is considered to derive the modified variable coefficients KdV equation. It is found that the presence of positively charged dust grains does not only significantly modify the basic properties of solitary structure, but also changes the polarity of the solitary profiles. In the vicinity of the critical ion density, neither KdV nor the modified KdV equation is appropriate for describing the DIAWs. Therefore, a further modified KdV equation is derived, which admits both soliton and double layer solutions.
Asgari, H.; Muniandy, S. V.; Wong, C. S.
2009-07-15
The effects of strength of dispersion on the formation of solitons and shock waves in unmagnetized dusty plasma are studied using reductive perturbative technique. Different relational forms of the strength parameter {epsilon} can be chosen to stretch the space and time variables, thereby leading to different types of nonlinearities. The Korteweg-de Vries (KdV) equation for the unmodulated dust acoustic wave is derived and the solitary wave solution is obtained. It is shown that there exists a critical dust density n{sub dc} at which the formation of the dust acoustic solitary waves is not possible. Furthermore, the solution of the KdV represents a rarefactive (compressive) solitary wave if n{sub d}
NASA Astrophysics Data System (ADS)
Bender, Brian; Thomas, Edward
2015-11-01
Using the DEMON (Dynamic Exploration of Microparticle clouds Optimized Numerically) code, a molecular dynamics simulation of dusty plasma was performed. In this simulation, an initial grid of particles is subjected to a uniform magnetic field and a perpendicular electric field whose magnitude increases radially. To analyze the output of the simulation, a single particle was chosen and a Fourier analysis of its trajectory is performed, revealing two primary frequencies that contain information about the E x B drift motion and the gyromotion of the particle. If the electric field only increases linearly, the difference between the two frequencies is the cyclotron frequency, which agrees with analytical results. If the electric field model is modified by an exponential decay term, then the frequencies depend on the particle's initial conditions. These results will help us to understand the electric field configuration of the MDPX device as well as highlight interesting parameter regimes for further study. This project is supported with funds from the NSF and Dept. of Energy.
Deeba, F.; Ahmad, Zahoor; Murtaza, G.
2006-08-15
The electrostatic potentials (Debye and wake) and energy loss due to a charged projectile propagating through an unmagnetized collisionless dusty plasma are derived employing kappa and generalized (r,q) velocity distributions for the dust acoustic wave. It is found that these quantities in general differ from their Maxwellian counterparts and are sensitive to the values of spectral index, {kappa} in the case of kappa distribution and to r, q in the case of generalized (r,q) distribution. The amplitudes of these quantities are less for small values of the spectral index ({kappa}, r=0, q) but approach the Maxwellian in the limit {kappa}{yields}{infinity} (for kappa distribution) and for r=0, q{yields}{infinity} [for generalized (r,q) distribution]. For any nonzero value of r, the potential and the energy loss grow beyond the Maxwellian results. The effect of kappa and generalized (r,q) distributions on potential and energy loss is also studied numerically and the results are compared with those of the Maxwellian distribution.
Finite size effects in the static structure factor of dusty plasmas
Davletov, A. E. Yerimbetova, L. T.; Mukhametkarimov, Ye. S.; Ospanova, A. K.
2014-07-15
Based on the previously developed pseudopotential model of the dust particles interaction, which takes into account both the finite size and screening effects, the equilibrium distribution functions are investigated in a broad range of plasma parameters. The treatment stems entirely from the renormalization theory of plasma particles interactions which leads to the so-called generalized Poisson-Boltzmann equation. In particular, an analytical expression for the static structure factor of the dust particles is proposed and its non-monotonic behavior in the hyper-netted chain approximation is found in a specified domain of plasma parameters to indicate the formation of short- or even long-range order in the system.
Alinejad, H.; Mamun, A. A.
2010-12-15
The combined effects of the flat-topped ion distribution and dust temperature are incorporated in the study of small but finite amplitude dust-acoustic (DA) solitary waves (SWs) as well double layers (DLs) in an unmagnetized dusty plasma. Due to the flat-trapped ions, our plasma model admits only rarefactive localized structures. It is found that the effects of dust temperature and resonant particles significantly modify the criteria for the existence of DA SWs and DLs, as well as significantly modify their basic properties.
NASA Astrophysics Data System (ADS)
Emad, K. El-Shewy; Abeer, A. Mahmoud; Ashraf, M. Tawfik; Essam, M. Abulwafa; Ahmed, Elgarayhi
2014-07-01
The KdV—Burgers equation for dust acoustic waves in unmagnetized plasma having electrons, singly charged nonthermal ions, and hot and cold dust species is derived using the reductive perturbation method. The Boltzmann distribution is used for electrons in the presence of the cold (hot) dust viscosity coefficients. The semi-inverse method and Agrawal variational technique are applied to formulate the space—time fractional KdV—Burgers equation which is solved using the fractional sub-equation method. The effect of the fractional parameter on the behavior of the dust acoustic shock waves in the dusty plasma is investigated.
Study of a CCP RF Dusty Plasma for the Production of Titan's Aerosols Analogues
Alcouffe, G.; Cernogora, G.; Ouni, F.; Correia, J. J.; Cavarroc, M.; Boufendi, L.; Szopa, C.
2008-09-07
The CCP-RF discharge PAMPRE experiment produces analogues of Titan's aerosols. Here are presented the plasma characteristics as a function of gas mixtures and dust formation. Electronic density, optical emission spectroscopy, and self-bias voltage measurements are presented.
The stability of weakly ionized collisional dusty plasma in the presence of flow
Pandey, B. P.; Vranjes, J.; Vladimirov, S. V.
2012-09-15
The stability of weakly ionized and magnetized plasma in the presence of transverse (to the magnetic field) neutral wind is investigated in the present work. The collisional coupling of ambient background flow to the magnetized plasma gives rise to an electric field. In the presence of charged unmagnetized dust, electrostatic fluctuations in such plasma become unstable, with the growth rate dependent on the plasma thermal speed as well as on the dust charge and collision frequencies. This instability is similar to the Farley-Buneman instability. However, unlike Farley-Buneman, where the growth rate is directly dependent on the background flow, this dependence in the present case is only indirect. It is shown that this instability can grow over few seconds in the Earth's lower ionosphere and thus could play an important role in the structure formation.
Analysis of mass transfer in dissipative nonideal systems: Experiments on dusty plasmas
Vaulina, O. S.; Adamovich, K. G. Petrov, O. F.; Fortov, V. E.
2008-08-15
Results of an experimental study of mass transfer are presented for extended systems of dust particles observed in capacitively coupled RF discharge plasmas. The Green-Kubo relation and the Langevin equation are validated as applied to dust grain dynamics in laboratory plasmas. A procedure is proposed for evaluating the temperature, friction coefficient, and characteristic oscillation frequency for dust grains. Measured characteristics of the dust subsystem (diffusion coefficient, pair correlation function, and friction coefficient) are compared with available theoretical and numerical results.
Instability due to trapped electrons in magnetized multi-ion dusty plasmas
NASA Astrophysics Data System (ADS)
Haider, M. M.; Ferdous, T.; Duha, S. S.
2015-05-01
An attempt has been made to find out the effects of trapped electrons in dust-ion-acoustic solitary waves in magnetized multi-ion plasmas, as in most space plasmas, the hot electrons follow the trapped/vortex-like distribution. To do so, we have derived modified Zakharov-Kuznetsov equation using reductive perturbation method and its solution. A small- perturbation technique was employed to find out the instability criterion and growth rate of such a wave.
Dust-acoustic supersolitons in a three-species dusty plasma with kappa distributions†
NASA Astrophysics Data System (ADS)
Hellberg, M. A.; Baluku, T. K.; Verheest, F.; Kourakis, I.; Kourakis
2013-12-01
Supersolitons are a form of soliton characterised, inter alia, by additional local extrema superimposed on the usual bipolar electric field signature. Previous studies of supersolitons supported by three-component plasmas have dealt with ion-acoustic structures. An analogous problem is now considered, namely, dust-acoustic supersolitons in a plasma composed of fluid negative dust grains and two kappa-distributed positive ion species. Calculations illustrating some supersoliton characteristics are presented.
Complex astrophysical experiments relating to jets, solar loops, and water ice dusty plasma
NASA Astrophysics Data System (ADS)
Bellan, P. M.; Zhai, X.; Chai, K. B.; Ha, B. N.
2015-10-01
> Recent results of three astrophysically relevant experiments at Caltech are summarized. In the first experiment magnetohydrodynamically driven plasma jets simulate astrophysical jets that undergo a kink instability. Lateral acceleration of the kinking jet spawns a Rayleigh-Taylor instability, which in turn spawns a magnetic reconnection. Particle heating and a burst of waves are observed in association with the reconnection. The second experiment uses a slightly different setup to produce an expanding arched plasma loop which is similar to a solar corona loop. It is shown that the plasma in this loop results from jets originating from the electrodes. The possibility of a transition from slow to fast expansion as a result of the expanding loop breaking free of an externally imposed strapping magnetic field is investigated. The third and completely different experiment creates a weakly ionized plasma with liquid nitrogen cooled electrodes. Water vapour injected into this plasma forms water ice grains that in general are ellipsoidal and not spheroidal. The water ice grains can become quite long (up to several hundred microns) and self-organize so that they are evenly spaced and vertically aligned.
NASA Astrophysics Data System (ADS)
Hosseini Jenab, S. M.; Kourakis, I.
2014-04-01
A series of numerical simulations based on a recurrence-free Vlasov kinetic algorithm presented earlier [Abbasi et al., Phys. Rev. E 84, 036702 (2011)] are reported. Electron-ion plasmas and three-component (electron-ion-dust) dusty, or complex, plasmas are considered, via independent simulations. Considering all plasma components modeled through a kinetic approach, the nonlinear behavior of ionic scale acoustic excitations is investigated. The focus is on Bernstein-Greene-Kruskal (BGK) modes generated during the simulations. In particular, we aim at investigating the parametric dependence of the characteristics of BGK structures, namely of their time periodicity (τtrap) and their amplitude, on the electron-to-ion temperature ratio and on the dust concentration. In electron-ion plasma, an exponential relation between τtrap and the amplitude of BGK modes and the electron-to-ion temperature ratio is observed. It is argued that both characteristics, namely, the periodicity τtrap and amplitude, are also related to the size of the phase-space vortex which is associated with BGK mode creation. In dusty plasmas, BGK modes characteristics appear to depend on the dust particle density linearly.
Anderson, H.M.; Radovanov, S.
1995-12-31
Particulate generation has been studied during reactive on etching (RIE) of oxide wafers in CF{sub 4}/CHF{sub 3} plasmas using the GEC Reference Cell. Under certain discharge process conditions, copious amounts of submicron particles form due to plasma interaction with the oxide substrate. Particles were observed in situ by laser light scattering (LLS) and dynamic laser light scattering (DLSS). DLLS can be used to determine information about particle size, motion, and growth dynamics. DLSS measurements show process-induced dust particles confined in an electrostatic trap exhibit low-frequency oscillatory motion consistent with charge density wave (CDW) motion. These results are also consistent with the plasma dust particles forming a strongly coupled Coulomb liquid phase.
Low-Frequency Electrostatic Shock Excitations in a Multi-Component Dusty Plasma
NASA Astrophysics Data System (ADS)
Ferdousi, M.; Miah, M. R.; Sultana, S.; Mamun, A. A.
2015-04-01
Dust-acoustic shock waves are investigated in a four-component plasma consisting of arbitrarily charged inertial dusts, Boltzmann distributed negatively charged heavy ions, positively charged light ions, and electrons. The reductive perturbation technique is employed in order to derive the nonlinear time evolution Burgers-type equation. The properties of dust-acoustic shock waves are analysed via the solution of Burgers equation. It is observed that the basic features of dust-acoustic shock waves are significantly modified due to the influence of arbitrarily charged dusts, Maxwellian electrons, number density and temperatures of heavier and lighter ions, and dust kinematic viscosity. Both polarity (positive and negative potential) shock waves are also found to exists in the plasma under consideration in this manuscript. The findings of this investigation may be used in understanding the dust-acoustic wave properties in both laboratory and space plasmas.
A note on the binary interaction potential in complex (dusty) plasmas
Khrapak, S. A.; Morfill, G. E.
2008-08-15
The effect of ion-neutral collisions on the potential of interaction between a pair of negatively charged grains in isotropic weakly collisional plasmas is investigated. Two interaction mechanisms are considered: Electric repulsion between like-charged grains and attraction due to the so-called ''ion shadow'' effect. It is demonstrated that in the presence of collisions, both interaction potentials exhibit Coulomb-like {proportional_to}r{sup -1} decay at large distances. A necessary condition for the existence of long-range attraction is derived. The obtained results are then used to reconsider the possibility of liquid-vapor critical point occurrence in complex plasmas.
Large amplitude double layers in a positively charged dusty plasma with nonthermal electrons
Djebli, M.; Marif, H.
2009-06-15
A pseudopotential approach is used to investigate large amplitude dust-acoustic solitary structures for a plasma composed of positively charged dust, cold electrons, and nonthermal hot electrons. Numerical investigation for an adiabatic situation is conducted to examine the existence region of the wave. The negative potential of the double layers is found to be dependent on nonthermal parameters, Mach number, and electrons temperature. A range of the nonthermal parameters values exists for which two possible double layers for the same plasma mix at different Mach numbers and with significant different amplitudes. The present model is used to investigate localized structures in the lower-altitude Earth's ionosphere.
2D-Combined ICP/CCP numerical modeling for RF plasma source
NASA Astrophysics Data System (ADS)
Miyashita, Masaru; Ikeda, Kei; Ochi, Syuta
2015-09-01
A numerical investigation of sputtering distribution on antenna cover in Radio Frequency (13.56 MHz) plasma(RF plasma) source by energetic ions bombardment has been performed including influences of static electric field from voltage of antenna and of inductive electric field from current of antenna. In order to validate the developed technique, the static electron heating distribution and the inductive electron heating distribution in simulation are compared. The comparison shows the static electric field is shielded in the sheath of the high electron density (1017m-3) plasma and the plasma is sustained by inductive electric field from current of antenna. The deep sheath potential in simulation is generated over the region of large vulnerable in experiment. The numerical simulation technique with calculating static electric field and inductive electric field is important for development of the RF plasma source with large current and long life time.
Laser-induced rocket force on a microparticle in a complex (dusty) plasma
Nosenko, V.; Ivlev, A. V.; Morfill, G. E.
2010-12-15
The interaction of a focused powerful laser beam with micron-sized melamine formaldehyde (MF) particles was studied experimentally. The microspheres had a thin palladium coating on their surface and were suspended in a radio frequency argon plasma as a single layer (plasma crystal). A particle hit by the laser beam usually accelerated in the direction of the laser beam, consistent with the radiation pressure force mechanism. However, random-direction acceleration up to the speeds on the order 1 m/s was sometimes observed. Rocket-force mechanism is proposed to account for the random-direction acceleration. Similar, but much less pronounced, effect was also observed for MF particles without palladium coating.
Arbitrary amplitude dust ion acoustic solitary waves in a magnetized suprathermal dusty plasma
Shahmansouri, M.; Alinejad, H.
2012-12-15
The linear and nonlinear dust-ion-acoustic (DIA) wave propagating obliquely with respect to an external magnetic field is studied in a magnetized complex plasma which consists of a cold ion fluid, superthermal electrons, and static dust particles. The propagation properties of two possible modes (in the linear regime) are investigated. It is found that the electron suprathermality and the electron population decrease the phase velocities of both modes, while obliqueness leads to increase of separation between two modes. An energy-like equation derived to describe the nonlinear evolution of DIA solitary waves. The influences of electron suprathermality, obliqueness, and electron population on the existence domain of solitary waves and the soliton characteristics are examined. It is shown that the existence domain of the DIA soliton and its profile are significantly depending on the deviation of electrons from thermodynamic equilibrium, electrons population, and obliqueness. It is also found that the suprathermal plasma supports the DIA solitons with larger amplitude.
Chekour, S.; Tahraoui, A.; Zaham, B.
2012-05-15
In this work, we have generalized the computation of Bohm criterion for electronegative complex plasma in the presence of fast monoenergetic electrons coming from a plane electrode. For this, we have established a 1D, collisionless, stationary, and unmagnetized electronegative plasma sheath model. The electrons and negative ions are considered in thermodynamic equilibrium; however, the positive ions, the dust grains, and the fast monoenergetic electrons are described by cold fluid equations. The generalized Bohm criterion has been calculated by using Sagdeev's pseudo potential method and the dust grain charge equation. The self-consistent relation between the dust grain surface potential at the edge and dust grains density is also derived. The numerical results reveal that the presence of the fast monoenergetic electrons increases the positive ion Mach number. On the other hand, the raise of electronegativity decreases this positive Mach number. The evolution of dust grain surface potential at the sheath edge is also illustrated and discussed.
Nonlinear ion-acoustic structures in dusty plasma with superthermal electrons and positrons
El-Tantawy, S. A.; El-Bedwehy, N. A.; Moslem, W. M.
2011-05-15
Nonlinear ion-acoustic structures are investigated in an unmagnetized, four-component plasma consisting of warm ions, superthermal electrons and positrons, as well as stationary charged dust impurities. The basic set of fluid equations is reduced to modified Korteweg-de Vries equation. The latter admits both solitary waves and double layers solutions. Numerical calculations indicate that these nonlinear structures cannot exist for all physical parameters. Therefore, the existence regions for both solitary and double layers excitations have been defined precisely. Furthermore, the effects of temperature ratios of ions-to-electrons and electrons-to-positrons, positrons and dust concentrations, as well as superthermal parameters on the profiles of the nonlinear structures are investigated. Also, the acceleration and deceleration of plasma species have been highlight. It is emphasized that the present investigation may be helpful in better understanding of nonlinear structures which propagate in astrophysical environments, such as in interstellar medium.
Wake turbulence observed behind an upstream “extra” particle in a complex (dusty) plasma
NASA Astrophysics Data System (ADS)
Zhdanov, S.; Du, C.-R.; Schwabe, M.; Nosenko, V.; Thomas, H. M.; Morfill, G. E.
2016-06-01
An interaction of upstream extra particles with a monolayer highly ordered complex plasma is studied. A principally new abnormal turbulent wake formed behind the supersonic upstream particle is discovered. An anomalous type of the turbulence wake clearly manifests in anomalously low thermal diffusivity and two orders of magnitude larger particle kinetic temperature compared to that of the “normal” wake (Mach cone) observed by Du et al. (EPL, 99 (2012) 55001).
Modified Jeans instability in Lorentzian dusty self-gravitating plasmas with Lennard-Jones potential
Qian, Y. Z. Chen, H. Liu, S. Q.
2014-11-15
The Jeans instability in self-gravitating plasma with Kappa distributed dust grains is investigated basing on assumption that the mutual interaction among dust grains is governed by Lennard-Jones potential. It is shown that the presence of additional suprathermal particles has significant effects on the range of unstable modes and growth rate of Jeans instability. Compared with Maxwellian scenario, suprathermality stabilized the Jeans instability.
NASA Astrophysics Data System (ADS)
Lee, Myoung-Jae; Jung, Young-Dae
2015-09-01
Nonthermal and positron effects on the dust acoustic surface waves propagating at the interface between a multi-component Lorentzian dusty plasma and a vacuum are investigated. The dispersion relation is kinetically derived by employing the specular reflection boundary condition and the dielectric permittivity for dusty plasma containing positrons. We found that there exist two modes of the dust acoustic surface wave; high- and low-frequency modes. We observe that both H- and L-modes are enhanced by the increase of the pair annihilation rate. However, the effects of positron density are duplex depending on the ratio of annihilated positrons. The effects of nonthermal plasmas are also investigated on the H- and L-modes of dust acoustic surface waves. We found that the nonthermal plasmas suppress the frequencies both H- and L-modes. This research was supported by Nuclear Fusion Research Program through NRF funded by the Ministry of Science, ICT & Future Planning (Grant No. 2015M1A7A1A01002786).
NASA Astrophysics Data System (ADS)
Saha, Asit; Chatterjee, Prasanta
2014-02-01
For the critical values of the parameters q and V, the work (Samanta et al. in Phys. Plasma 20:022111, 2013b) is unable to describe the nonlinear wave features in magnetized dusty plasma with superthermal electrons. To describe the nonlinear wave features for critical values of the parameters q and V, we extend the work (Samanta et al. in Phys. Plasma 20:022111, 2013b). To extend the work, we derive the modified Kadomtsev-Petviashvili (MKP) equation for dust ion acoustic waves in a magnetized dusty plasma with q-nonextensive velocity distributed electrons by considering higher order coefficients of ɛ. By applying the bifurcation theory of planar dynamical systems to this MKP equation, the existence of solitary wave solutions of both types rarefactive and compressive, periodic travelling wave solutions and kink and anti-kink wave solutions is proved. Three exact solutions of these above waves are determined. The present study could be helpful for understanding the nonlinear travelling waves propagating in mercury, solar wind, Saturn and in magnetosphere of the Earth.
Evolution of ion-acoustic solitary waves in Maxwellian dusty plasmas
Das, G. C.; Choudhury, Balen; Bora, M. P.
2010-12-15
The nonlinear wave phenomena in the vicinity of Korteweg-de Vries (KdV) equation have been derived to study the salient features of solitons in a complex plasma consisting of Maxwellian electrons, ions, and cold dust with the effect of dust charge fluctuation. The reductive perturbation method has been applied to the dynamical system causeway and the derived KdV equation predicts different natures of solitons in complex plasma. The dynamics of the soliton propagation in the considered plasma constituents in ionospheric auroral regions exhibits rarefactive solitons, which is an interesting feature. The dust charge fluctuation by the increasing impact of electrons leads the nonlinear effect to be tending to zero. Because of which, the formation of a narrow solitary wave packet with the generation of high energy becomes possible and results in the phenomena of soliton radiation. In order to probe this further, we derive a modified KdV equation to study soliton propagation which, in turn, indicates the possibility of the shock formation in solitary waves.
Dust ion-acoustic shocks in quantum dusty pair-ion plasmas
Misra, A. P.
2009-03-15
The formation of dust ion-acoustic shocks in a four-component quantum plasma whose constituents are electrons, both positive and negative ions, and immobile charged dust grains, is studied. The effects of both the dissipation due to kinematic viscosity and the dispersion caused by the charge separation as well as the quantum tunneling associated with the Bohm potential are taken into account. The propagation of small but finite amplitude dust ion-acoustic waves is governed by the Korteweg-de Vries-Burger equation, which exhibits both oscillatory and monotonic shocks depending not only on the viscosity parameters {eta}{sub {+-}}={mu}{sub {+-}}{omega}{sub p-}/c{sub s}{sup 2} (where {mu}{sub {+-}} are the coefficients of kinematic viscosity, {omega}{sub p-} is the plasma frequency for negative ions, and c{sub s} is the ion-sound speed), but also on the quantum parameter H (the ratio of the electron plasmon to the electron Fermi energy) and the positive to negative ion density ratio {beta}. Large amplitude stationary shocks are recovered for a Mach number (M) exceeding its critical value (M{sub c}). Unlike the small amplitude shocks, quite a smaller value of {eta}{sub +}, {eta}{sub -}, H and {beta} may lead to the large amplitude monotonic shock structures. The results could be of importance in astrophysical and laser produced plasmas.
Time-Dependent 2D Modeling of Magnetron Plasma Torch in Turbulent Flow
NASA Astrophysics Data System (ADS)
Li, Lincun; Xia, Weidong
2008-06-01
A theoretical model is presented to describe the electromagnetic, heat transfer and fluid flow phenomena within a magnetron plasma torch and in the resultant plume, by using a commercial computational fluid dynamics (CFD) code FLUENT. Specific calculations are presented for a pure argon system (i.e., an argon plasma discharging into an argon environment), operated in a turbulent mode. An important finding of this work is that the external axial magnetic field (AMF) may have a significant effect on the behavior of arc plasma and thus affects the resulting plume. The AMF impels the plasma to retract axially and expand radially. As a result, the plasma intensity distribution on the cross section of torch seems to be more uniform. Numerical results also show that with AMF, the highest plasma temperature decreases and the anode arc root moves upstream significantly, while the current density distribution at the anode is more concentrated with a higher peak value. In addition, the use of AMF then induces a strong backflow at the torch spout and its magnitude increases with the AMF strength but decreases with the inlet gas velocity.
Study of Unsteady Flow Actuation Produced by Surface Plasma Actuator on 2-D Airfoil
NASA Astrophysics Data System (ADS)
Phan, Minh Khang; Shin, Jichul
2014-10-01
Effect of flow actuation driven by low current continuous or pulsed DC surface glow discharge plasma actuator is studied. Schlieren image of induced flow on flat plate taken at a high repetition rate reveals that the actuation is mostly initiated near the cathode. Assuming that the actuation is mostly achieved by ions in the cathode sheath region, numerical model for the source of flow actuation is obtained by analytical estimation of ion pressure force created in DC plasma sheath near the cathode and added in momentum equation as a body force term. Modeled plasma flow actuator is simulated with NACA0012 airfoil oscillating over a certain range of angle of attack (AoA) at specific reduced frequencies of airfoil. By changing actuation authority according to the change in AoA, stabilization of unsteady flow field is improved and hence steady aerodynamic performance can be maintained. Computational result shows that plasma actuation is only effective in modifying aerodynamic characteristics of separated flow. It turns out that plasma pulse frequency should be tuned for optimal performance depending on phase angle and rotating speed. The actuation authority can be parameterized by a ratio between plasma pulse frequency and reduced frequency.
Modelling elements for the Moon s near surface dusty plasma environment characterization
NASA Astrophysics Data System (ADS)
Cipriani, F.; Hilgers, A. M.
2011-12-01
F. Cipriani (1), A. Hilgers(1), D. Rodgers(1) (1) ESA/ESTEC, Noordwijk, The Netherlands (fabrice.cipriani@esa.int / Fax: +31-71-5654697) Characterizing the Moon's electrostatically charged regolith, the levitation and transport of charged dust grains and their role in the surface current balance, is of primary importance to prepare future lunar missions. Observations carried out during Apollo missions brought evidence for a dust levitation process [1] and allowed to study lunar grains charging characteristics [2]. Lately, Lunar Prospector electron reflectometry data allowed to gain insights into the magnitude and the variability of lunar surface charging, revealing significant electrostatic potentials under different plasma conditions, depending on the Moon's local environment (Solar Wind, tail lobes, Earth's plasma sheet) (see e.g. [3,4]). Although theoretical studies have tackled the problem of regolith and dust grains charging, numerical modeling tools can be useful to simulate dust charging and transport over the complex features of the lunar topography, including the effects of the near surface magnetic environment, and interaction with mission elements as a lunar lander [5]. In the present study we use on the one hand a 3D PIC simulation code to investigate, under simplifying assumptions: 1) charging of the lunar surface under different plasma conditions encountered along the Moon orbit, 2) charging of a complex surface feature (typically a crater), and 3) charging, levitation and transport of dust grains in the near surface environment. One the other hand, we analyze limitations of the current tool and the physics to be further implemented in order to address dust charging and transport processes at the Moon surface relevant to the exploration of the Moon. References [1] Stubbs et al, (2006) Advance in Space Research, 37, 59-66 [2] Horanyi et al, (1998) JGR, Volume 103, Issue E4 [3] Halekas et al, (2008) JGR, Volume 113, Issue A9 [4] Poppe et al, (2011) GRL
Self-organized field structures in electron-depleted multi-ion dusty plasma
NASA Astrophysics Data System (ADS)
Iqbal, M.; Gondal, S. M.; Shuaib, A.; Qurat-Ul-Ain
2015-06-01
It is shown that there exists a strong interaction between the magnetic and kinetic aspects of a multi-ion plasma. The interaction appears as a system of simultaneous equations which show the alignment of vortices to flows and satisfy the Beltrami condition. Solving these equations lead to a non-force-free magnetic field which can be cast as a superposition of three multiscale force-free magnetic field configurations. It is the consequence of different Beltrami parameters of positive and negative ion fluids. It is also shown that self-organized paramagnetic and diamagnetic field structures could be created by varying the vorticities and flows of ion fluids.
Nonlinear dust phase-space vortices (holes) in charge-varying dusty plasmas
Tribeche, Mouloud; Aoutou, Kamel; Zerguini, Taha Houssine
2005-03-01
The recent analysis of dust voids [A. A. Mamun and P. K. Shukla, Phys. Plasmas 11, 1757 (2004)] is extended to include self-consistently the dust charge variation. Numerical solutions of highly nonlinear equations are carried out including dust charging and dust trapping. It is found that under certain conditions the effect of dust charge variation can be quite important. In particular, it may be noted that the dust charge variation leads to an additional enlargement of the nonlinear dust voids. The effects of ion/electron temperature, trapping parameter, and dust size on the properties of these nonlinear dust voids are briefly discussed.
Externally and self-excited nonlinear waves in a dusty plasma.
NASA Astrophysics Data System (ADS)
Zhang, Bo; Qiao, Ke; Kong, Jie; Matthews, Lorin; Hyde, Truell
2015-11-01
Recently it has been shown that strongly coupled three-dimensional dust clouds can be easily levitated in the plasma sheath region of a glass box coated with a transparent yet conductive layer of indium tin oxide (ITO). Gradually reducing the neutral gas pressure below a critical value of ~350 mTorr establishes self-excited waves within this system. In this paper, it will be shown that decreasing the ITO bias to -20 V allows waves to be externally induced within the lower region of the dust cloud. The underlying physics and synergistic effect of changing the pressure and/or ITO bias on these waves will be examined as will the onset of instabilities and the evolution of the dust density waves for ITO biases ranging from 0 to -40 V. Finally, the dust charge will be estimated by assuming the waves oscillate at the dust plasma frequency. Support from the NSF and the DOE (award numbers PHY-1262031 and PHY-1414523) is gratefully acknowledged.
Spatio-temporal evolution of the dust particle size distribution in dusty argon rf plasmas
NASA Astrophysics Data System (ADS)
Killer, Carsten; Mulsow, Matthias; Melzer, André
2015-04-01
An imaging Mie scattering technique has been developed to measure the spatially resolved size distribution of dust particles in extended dust clouds. For large dust clouds of micrometre-sized plastic particles confined in an radio frequency (rf) discharge, a segmentation of the dust cloud into populations of different sizes is observed, even though the size differences are very small. The dust size dispersion inside a population is much smaller than the difference between the populations. Furthermore, the dust size is found to be constantly decreasing over time while the particles are confined in an inert argon plasma. The processes responsible for the shrinking of the dust in the plasma have been addressed by mass spectrometry, ex situ microscopy of the dust size, dust resonance measurements, in situ determination of the dust surface temperature and Fourier transform infrared absorption (FT-IR). It is concluded that both a reduction of dust size and its mass density due to outgassing of water and other volatile constituents as well as chemical etching by oxygen impurities are responsible for the observations.
Wave processes in dusty plasma near the Moon’s surface
Morozova, T. I.; Kopnin, S. I.; Popel, S. I.
2015-10-15
A plasma—dust system in the near-surface layer on the illuminated side of the Moon is described. The system involves photoelectrons, solar-wind electrons and ions, neutrals, and charged dust grains. Linear and nonlinear waves in the plasma near the Moon’s surface are discussed. It is noticed that the velocity distribution of photoelectrons can be represented as a superposition of two distribution functions characterized by different electron temperatures: lower energy electrons are knocked out of lunar regolith by photons with energies close to the work function of regolith, whereas higher energy electrons are knocked out by photons corresponding to the peak at 10.2 eV in the solar radiation spectrum. The anisotropy of the electron velocity distribution function is distorted due to the solar wind motion with respect to photoelectrons and dust grains, which leads to the development of instability and excitation of high-frequency oscillations with frequencies in the range of Langmuir and electromagnetic waves. In addition, dust acoustic waves can be excited, e.g., near the lunar terminator. Solutions in the form of dust acoustic solitons corresponding to the parameters of the dust—plasma system in the near-surface layer of the illuminated Moon’s surface are found. Ranges of possible Mach numbers and soliton amplitudes are determined.
NASA Technical Reports Server (NTRS)
Zimmerman, Michael I.; Farrell, W. M.; Snubbs, T. J.; Halekas, J. S.
2011-01-01
Anticipating the plasma and electrical environments in permanently shadowed regions (PSRs) of the moon is critical in understanding local processes of space weathering, surface charging, surface chemistry, volatile production and trapping, exo-ion sputtering, and charged dust transport. In the present study, we have employed the open-source XOOPIC code [I] to investigate the effects of solar wind conditions and plasma-surface interactions on the electrical environment in PSRs through fully two-dimensional pattic1e-in-cell simulations. By direct analogy with current understanding of the global lunar wake (e.g., references) deep, near-terminator, shadowed craters are expected to produce plasma "mini-wakes" just leeward of the crater wall. The present results (e.g., Figure I) are in agreement with previous claims that hot electrons rush into the crater void ahead of the heavier ions, fanning a negative cloud of charge. Charge separation along the initial plasma-vacuum interface gives rise to an ambipolar electric field that subsequently accelerates ions into the void. However, the situation is complicated by the presence of the dynamic lunar surface, which develops an electric potential in response to local plasma currents (e.g., Figure Ia). In some regimes, wake structure is clearly affected by the presence of the charged crater floor as it seeks to achieve current balance (i.e. zero net current to the surface).
Katoh, Yasuhiro; Uchida, Shinya; Kawai, Masayoshi; Takei, Noriyoshi; Mori, Norio; Kawakami, Junichi; Kagawa, Yoshiyuki; Yamada, Shizuo; Namiki, Noriyuki; Hashimoto, Hisakuni
2010-01-01
Fluvoxamine is a selective serotonin reuptake inhibitor widely used in the treatment of depression and other psychiatric diseases. The aim of this study was to assess the clinical impact of cigarette smoking on plasma fluvoxamine concentration in Japanese patients, and evaluate whether the cytochrome P450 (CYP) 1A2 and CYP2D6 genotypes have effects on that concentration. Thirty-two Japanese patients receiving fluvoxamine were enrolled. They were maintained on the same daily dose of fluvoxamine (mean + or - S.D., 109.4 + or - 66.2 mg/d) for at least 4 weeks to obtain the steady-state plasma concentration. The steady-state plasma concentration-to-dose (C/D) ratio of fluvoxamine in patients who smoked (n = 6, 11.8 + or - 6.5 ng/ml/dose) was significantly lower than that in non-smoker patients (n = 26, 22.8 + or - 11.2 ng/ml/dose). There was no significant difference for the C/D ratio of fluvoxamine in patients with CYP1A2 -3860G/G, -3860G/A, and -3860A/A between non-smokers and smokers. Among non-smoker patients, the C/D ratios of fluvoxamine in those with one and two mutated alleles of CYP2D6 were 1.6- and 1.4-fold higher, respectively, than those with no mutated alleles, though the differences among those three genotype groups were not significant. Furthermore, stepwise multiple regression analysis revealed that cigarette smoking and daily dose had significant positive correlations with the plasma concentration of fluvoxamine. Our findings suggest that cigarette smoking has a significant impact on the steady-state plasma concentration of fluvoxamine in Japanese patients. PMID:20118554
Banerjee, Gadadhar; Maitra, Sarit
2015-04-15
Sagdeev's pseudopotential method is used to study small as well as arbitrary amplitude dust acoustic solitons in a dusty plasma with kappa distributed electrons and ions with dust grains having power law size distribution. The existence of potential well solitons has been shown for suitable parametric region. The criterion for existence of soliton is derived in terms of upper and lower limit for Mach numbers. The numerical results show that the size distribution can affect the existence as well as the propagation characteristics of the dust acoustic solitons. The effect of kappa distribution is also highlighted.
NASA Astrophysics Data System (ADS)
Sayyar, M.; Zahed, H.; Pestehe, S. J.; Sobhanian, S.
2016-07-01
Using the Sagdeev pseudo-potential method, the oblique propagation of dust-ion acoustic solitary waves is studied in a magnetized dusty plasma. By considering non-thermal distribution of electrons, the related pseudo-potential is obtained using the Poisson equation. The behavior of the wave is investigated for some ranges of parameters. It is demonstrated that the increase in ion density, lz, β, and also δ1 can lead to the increases in the width and amplitude of the pseudo-potential, while any increase of a2, the coefficient that describes the first nonlinear term in the G ( ϕ ) , increases the amplitude of the V ( ϕ ) .
NASA Astrophysics Data System (ADS)
Sarkar, Sanjib; Barman, Chiranjib; Mondal, Malay; Bose, M.; Mukherjee, S.
2016-05-01
Analysis of defects in externally driven dust-density wavefronts (DDWs) in cogenerated dusty plasma has been carried out. The DDWs are excited for threshold positive bias through another T-shaped electrode which is placed inbetween two main discharge electrodes. Spatiotemporal evolution of the DDWs reveals a wave defect and non-propagating wave mode in the DDW field. A space-time plot and the time-resolved Hilbert–Huang transform (HHT) were employed to analyze the spatiotemporal wave data at a specific location in the wave field.
Higher-order corrections to dust ion-acoustic soliton in a quantum dusty plasma
Chatterjee, Prasanta; Das, Brindaban; Mondal, Ganesh; Muniandy, S. V.; Wong, C. S.
2010-10-15
Dust ion-acoustic soliton is studied in an electron-dust-ion plasma by employing a two-fluid quantum hydrodynamic model. Ions and electrons are assumed to follow quantum mechanical behaviors in dust background. The Korteweg-de Vries (KdV) equation and higher order contribution to KdV equations are derived using reductive perturbation technique. The higher order contribution is obtained as a higher order inhomogeneous differential equation. The nonsecular solution of the higher order contribution is obtained by using the renormalization method and the particular solution of the inhomogeneous equation is determined using a truncated series solution method. The effects of dust concentration, quantum parameter for ions and electrons, and soliton velocity on the amplitude and width of the dressed soliton are discussed.
The magnetized sheath of a dusty plasma with grains size distribution
Ou, Jing Gan, Chunyun; Lin, Binbin; Yang, Jinhong
2015-05-15
The structure of a plasma sheath in the presence of dust grains size distribution (DGSD) is investigated in the multi-fluid framework. It is shown that effect of the dust grains with different sizes on the sheath structure is a collective behavior. The spatial distributions of electric potential, the electron and ion densities and velocities, and the dust grains surface potential are strongly affected by DGSD. The dynamics of dust grains with different sizes in the sheath depend on not only DGSD but also their radius. By comparison of the sheath structure, it is found that under the same expected value of DGSD condition, the sheath length is longer in the case of lognormal distribution than that in the case of uniform distribution. In two cases of normal and lognormal distributions, the sheath length is almost equal for the small variance of DGSD, and then the difference of sheath length increases gradually with increase in the variance.
NASA Astrophysics Data System (ADS)
Sabetkar, Akbar; Dorranian, Davoud
2016-08-01
Our prime objective of this paper is to examine the parametric regimes for the existence and polarity of dust acoustic double layers (DADLs) and its solitary structures arising from a magnetized self-gravitating opposite polarity dust-plasma (OPDP) model. The constituents of the OPDP model are two species of positively and negatively charged dust grains, Maxwellian electrons and kappa distributed ions. Contributions of gravitational force only on dust grains are taken into account. For weakly nonlinear analysis, the multiple time scale technique has been used to construct the extended Korteweg-de Vries (E-KdV) and modified Korteweg-de Vries (M-KdV) equations. They pinpoint the evolution of DADLs and solitary structures associated with dust acoustic (DA) mode, respectively. The relevant configurational parameters in our study include the superthermality of ions (κ), obliqueness of propagation (θ), ion concentration (δi), static magnetic field B0 (via ω c p , ω c n ), and self-gravitational field (via γ), as well as the density (μ0), charge (α), and mass (β) ratio of positive to negative dust species. The proposed OPDP model permits positive and negative double layer polarities, while higher order nonlinear equation dictates us only positive polarity solitary structures. The main modification due to an increase in self-gravitational field (via γ) is an enhancement in the spatial width of double layers, yet leaving their amplitude, phase speed, and polarity practically unaffected. With enhanced superthermality and other intrinsic parameters in OPDP model, there is an opposite trend in both amplitude and width of double layers, while the amplitude and the width of solitary waves (via M-KdV equation) undergo the identical behaviors. In particular, the amplitude of solitary waves manifests monotonic behavior for permissible range of obliqueness θ, whereas this scenario is acceptable to only width of double layers. The results are discussed in the context of
NASA Astrophysics Data System (ADS)
Araghi, F.; Dorranian, D.
2016-02-01
Effect of dust electrical charge fluctuations on the nature of dust acoustic solitary waves (DASWs) in a four-species magnetized dusty plasma containing nonextensive electrons and two-temperature isothermal ions has been investigated. In this model, the negative dust electric charge is considered to be proportional to the plasma space potential. The nonlinear Zakharov-Kuznetsov (ZK) and modified Zakharov-Kuznetsov (mZK) equations are derived for DASWs by using the standard reductive perturbation method. The combined effects of electron nonextensivity and dust charge fluctuations on the DASW profile are analyzed. The different ranges of the nonextensive q-parameter are considered. The results show that solitary waves the amplitude and width of which depend sensitively on the nonextensive q-parameter can exist. Due to the electron nonextensivity and dust charge fluctuation rate, our dusty plasma model can admit both positive and negative potential solitons. The results show that the amplitude of the soliton increases with increasing electron nonextensivity, but its width decreases. Increasing the electrical charge fluctuations leads to a decrease in both the amplitude and width of DASWs.
Optical properties of analogs of Titan's aerosols produced by dusty plasma
NASA Astrophysics Data System (ADS)
Hadamcik, E.; Renard, J.-B.; Mahjoub, A.; Gautier, T.; Carrasco, N.; Cernogora, G.; Szopa, C.
2013-10-01
Analogs of Titan's aerosols are produced in the laboratory as grains in a gas mixture, or as layers on a substrate. This production procedure enables the methane-nitrogen mixture composition to be changed. The aim of this paper is to understand the variations observed on the linear polarization of the scattered light as a function of the production conditions. The influence of the concentration of methane injected in the plasma will be discussed and compared with the previous work of Hadamcik et al. (2009a). The diameter of the grains are measured by SEM-FEG images. The decrease of absorption with increasing wavelength, measured by spectroscopic ellipsometry on layers, is observed for a decreasing initial methane ratio and analyzed in terms of an increasing `amine' content in the materials. The phase function parameters of the linear polarization of the scattered light are discussed in terms of the diameters of the aggregates and of the constituent grains, and the variation of the refractive indices (mainly absorption). The polarization is found to be highly correlated with the constituent grain size. Finally, the experimental results are compared to polarization measurements from space of the Titan's atmosphere.
Recent Results from a Laboratory Study of Charging Mechanisms in a Dusty Plasma
NASA Technical Reports Server (NTRS)
Venturini, Catherine C.; Spann, James F., Jr.; Comfort, Richard H.
1998-01-01
A laboratory investigation has been developed to experimentally study the interaction of micron sized particles with plasmas and electromagnetic radiation. The intent is to investigate under what conditions particles of various compositions and sizes become charged, or discharged, while exposed to an electron beam and UV radiation. This investigation uses a unique laboratory technique known as electrodynamic suspension of particles. Here, a single charged micron size particle is suspended in a quadrupole trap and then subjected to a controlled environment. In this paper, we will discuss recent results from this experiment in which different materials including polystyrene and aluminum oxide, and sizes ranging from 10 microns to 1 micron have been used to determine charge to mass ratios and then subjected to an electron beam and /or UV radiation. In each instance, the particle's charge as well as beam current flux and radiation intensity flux is measured. These results will be compared with initial results using salt crystals. It was found that a negatively charged salt crystal exposed for 30 minutes to a 500 eV electron beam with primary electron beam current of -3.06 x 10(exp -5) picoamps yielded a secondary electron current of 3.23 x 10(exp -5) picoamps. Additionally, the particle was observed to be steadily losing charge over this time interval. By studying the microphysics of one particle, a better understanding of theoretical models and other laboratory results associated with particle charging mechanisms can be achieved.
Usachev, Alexander; Zobnin, Andrey; Petrov, Oleg; Fortov, Vladimir
2008-09-07
In present experiment an ordering and dynamics of monodisperse nylon rods (D = 10 {mu}m, L = 300 {mu}m) in a uniform DC gas discharge plasma under microgravity have been investigated. Ordered rod structures were registered in DC discharge with a rod concentration of 400-8000 cm{sup -3} and a neon pressure range of 20-50 Pa. The structures revealed orientationally ordered hexagonal structures. DC discharge became unstable at rod number density more then 8000 cm{sup -3}. Rod drift velocities in a permanent electric field were measured for the neon pressure range. Dust acoustic instability ({nu}{approx}0.4{+-}0.1 Hz, {lambda}{approx}1.1{+-}0.4 cm, C{sub DAW}{approx}0.5 cm/s) in rod cloud was observed at a neon pressure of 25 Pa and a rod number density of 1500 cm{sup -3}. Using the 'low' frequency approximation of the linearized DAW dispersion relation and the measured rod drift velocity a rod electric charge had been estimated as Z{sub R}{approx}150000e.
Cox, Steven T; Laza-Briviesca, Raquel; Pearson, Hayley; Soria, Bernat; Gibson, Daniel; Gomez, Susana; Madrigal, J Alejandro; Saudemont, Aurore
2015-08-01
NK cells play a key role in innate elimination of virally infected or neoplastic cells but they can be circumvented by immunoevasive mechanisms enabling viral spread or tumor progression. Engagement of the NKG2D activating receptor with soluble forms of its ligand is one such mechanism of inducing NK cell hyporesponsiveness. Interestingly, this immunoevasive strategy among others is described at the maternal-fetal interface where tolerance of the semi-allogeneic fetus is required to allow successful human pregnancy. Understanding of maternal-fetal tolerance is increasing but mechanisms preventing alloreactivity of fetal immune cells against the maternal host are less well understood. The study of umbilical cord blood has enabled insight of the fetal immune system, which appears immature and inert. We have found that soluble NKG2D ligands (sNKG2DLs) are present in cord blood plasma (CBP) and associate with adult NK cell hyporesponsiveness demonstrated by reduced CD107a expression and secretion of IFN-γ upon stimulation. The capacity of NK cells to kill K562 cells or proliferate was also reduced by incubation with CBP; however, physical removal of sNKG2DL from CBP restored K562 lytic function and NKG2D expression. Therefore, our results strongly suggest sNKG2DLs are expressed in CBP as a mechanism of fetal-maternal tolerance in human pregnancy. PMID:25991034
NASA Astrophysics Data System (ADS)
Lai, Hairong
Interplanetary field enhancements (IFEs) are unique large-scale structures in the solar wind. During IFEs, the magnetic-field strength is significantly enhanced with little perturbation in the solar-wind plasma. Early studies showed that IFEs move at nearly the solar-wind speed and some IFEs detected at 0.72AU by Pioneer Venus Orbiter (PVO) are associated with material co-orbiting with asteroid Oljato. To explain the observed IFE features, we develop and test an IFE formation hypothesis: IFEs result from interactions between the solar wind and clouds of nanoscale charged dust particles released in interplanetary collisions. This hypothesis predicts that the magnetic field drapes and the solar wind slows down in the upstream. Meanwhile the observed IFE occurrence rate should be comparable with the detectable interplanetary collision rate. Based on this hypothesis, we can use the IFE occurrence to determine the spatial distribution and temporal variation of interplanetary objects which produce IFEs. To test the hypothesis, we perform a systematic survey of IFEs in the magnetic-field data from many spacecraft. Our datasets cover from 1970s to present and from inner than 0.3AU to outer than 5 AU. In total, more than 470 IFEs are identified and their occurrences show clustering features in both space and time. We use multi-spacecraft simultaneous observations to reconstruct the magnetic-field geometry and find that the magnetic field drapes in the upstream region. The results of a superposed epoch study show that the solar wind slows down in the upstream and there is a plasma depletion region near the IFE centers. In addition, the solar-wind slowdown and plasma depletion feature are more significant in larger IFEs. The mass contained in IFEs can be estimated by balancing the solar-wind pressure force exerted on the IFEs against the solar gravity. The solar-wind slowdown resultant from the estimated mass is consistent with the result in superposed epoch study. The
NASA Astrophysics Data System (ADS)
Sabetkar, Akbar; Dorranian, Davoud; Dorranian
2014-08-01
The nonlinear Zakharov-Kuznetsov and the modified Zakharov-Kuznetsov equations are derived for dust-acoustic solitary waves (DASWs) in a magnetized four-component dusty plasma system comprising negatively charged cold dust, non-extensive electrons, and two-temperature thermal ions using standard reductive perturbation method. The combined effects of electron non-extensivity, strength of magnetic field, and its obliqueness on the DASWs profile are analyzed. Different ranges of non-extensive q-parameter are considered. Our results show that solitary waves, that their amplitude and width of which depend sensitively on the q-non-extensive parameter, can exist. Due to electron non-extensivity, our dusty plasma model can admit positive potential as well as negative potential solitons. The strength of magnetic field has no effect on the amplitude of solitary waves, whereas its obliqueness affects both amplitude and width of the solitary waves structure. Results show that the amplitude of soliton increases with increasing the velocity of soltion. For any magnitude of q there is an extremum for the direction of the magnetic field at which the width of soliton is maximum.
Shahmansouri, M.; Mamun, A. A.
2014-03-15
Linear and nonlinear propagation of dust-acoustic waves in a magnetized strongly coupled dusty plasma is theoretically investigated. The normal mode analysis (reductive perturbation method) is employed to investigate the role of ambient/external magnetic field, obliqueness, and effective electrostatic dust-temperature in modifying the properties of linear (nonlinear) dust-acoustic waves propagating in such a strongly coupled dusty plasma. The effective electrostatic dust-temperature, which arises from strong electrostatic interactions among highly charged dust, is considered as a dynamical variable. The linear dispersion relation (describing the linear propagation characteristics) for the obliquely propagating dust-acoustic waves is derived and analyzed. On the other hand, the Korteweg-de Vries equation describing the nonlinear propagation of the dust-acoustic waves (particularly, propagation of dust-acoustic solitary waves) is derived and solved. It is shown that the combined effects of obliqueness, magnitude of the ambient/external magnetic field, and effective electrostatic dust-temperature significantly modify the basic properties of linear and nonlinear dust-acoustic waves. The results of this work are compared with those observed by some laboratory experiments.