scholarly journals Simulations of two-stream instability in opposite polarity dusty plasmas

2012 ◽  
Vol 78 (3) ◽  
pp. 211-224
Author(s):  
S. ERIC CLARK ◽  
M. ROSENBERG ◽  
K. QUEST

AbstractOne-dimensional Particle in Cell simulations of a dust–dust counterstreaming instability in a plasma containing dust grains of opposite charge polarity are presented. This dust–dust instability has potentially the lowest threshold drift for a dust wave instability in an unmagnetized dusty plasma. The linear and nonlinear development of this instability is investigated, including the effects of collisions with background neutrals, and a background electric field that acts as a driver to impart the drift velocities of the counter-streaming oppositely charged dust particles. The saturation of the linear instability appears to be due to dust heating related to dust trapping. Potential double layer formation from dust–dust instability turbulence is observed in cases with a high neutral collision rate. A comparative study is done with varying collision rates and background electric fields to explore the nonlinear development as a function of collision rate and background electric field. Applications to possible dusty plasma experimental parameters are discussed.

2018 ◽  
Vol 84 (6) ◽  
Author(s):  
M. Rosenberg ◽  
K. Quest ◽  
B. Kercher

The nonlinear development of a low frequency beam-cyclotron instability in a collisional plasma composed of magnetized ions and electrons and unmagnetized, negatively charged dust is investigated using one-dimensional particle-in-cell simulations. Collisions of charged particles with neutrals are taken into account via a Langevin operator. The instability, which is driven by an ion $\boldsymbol{E}\times \boldsymbol{B}$ drift, excites a quasi-discrete wavenumber spectrum of waves that propagate perpendicular to the magnetic field with frequency of the order of the dust plasma frequency. In the linear regime, the unstable wavelengths are of the order of the ion gyroradius. As the wave energy density increases, the dominant modes shift to longer wavelengths, suggesting a transition to a Hall-current-type instability. Parameters are considered that reflect the ordering of plasma and dust quantities in laboratory dusty plasmas with high magnetic field. Comparison with the nonlinear development of this beam cyclotron instability in a collisionless dusty plasma is also briefly discussed.


2013 ◽  
Vol 79 (4) ◽  
pp. 405-411 ◽  
Author(s):  
SERGEY I. POPEL ◽  
LEV M. ZELENYI

AbstractFrom 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.


2019 ◽  
Author(s):  
Nirmalya Basu

There is a proposition that the possible occurrence of electrostatic discharges inside an oxygen regulator between charged insulating components, such as diaphragms, and earthed metal components, such as the valve stem, could be a potential candidate responsible for oxygen regulator fires. In this paper, the electric field which might be produced at the tip of the valve stem due to charge produced on the diaphragm of a typical oxygen regulator by deposition of charged dust particles or by their impact on the diaphragm or both has been evaluated. The diaphragm, in many cases, is backed partially by a concentric earthed metal disk. The diaphragm has been modelled as an insulating disk. The tip of the valve stem has been modelled as an earthed sphere which is very small compared to the insulating disk and the backing earthed metal disk. An analytical expression for the electric field produced at the point of the sphere nearest to the charged surface of the insulator has been derived. Our expression takes into account not only the effect of the charge on the insulating disk, but also that due to the presence of the backing earthed metal disk. Results for the magnitude of this electric field have been computed for the case of a sample oxygen regulator. An expression for the critical charge density on the surface of the insulating disk has been derived, and its value has been obtained for the case of our sample oxygen regulator. The electric field inside the non-metal diaphragm has also been evaluated. It appears from our analyses that there is a possibility that an electrostatic discharge might occur inside an oxygen regulator, and with an enriched-oxygen atmosphere being present there, such a discharge could also lead to a fire incident.


2008 ◽  
Vol 74 (5) ◽  
pp. 601-605 ◽  
Author(s):  
M. MARKLUND ◽  
L. STENFLO ◽  
P. K. SHUKLA

AbstractThe existence of magnetosonic solitons in dusty plasmas is investigated. The nonlinear magnetohydrodynamic equations for a warm dusty magnetoplasma are thus derived. A solution of the nonlinear equations is presented. It is shown that, owing to the presence of dust, static structures are allowed. This is in sharp contrast to the formation of the so-called shocklets in usual magnetoplasmas. A comparatively small number of dust particles can thus drastically alter the behavior of the nonlinear structures in magnetized plasmas.


2009 ◽  
Vol 75 (3) ◽  
pp. 413-431 ◽  
Author(s):  
A. A. MAMUN ◽  
N. JAHAN ◽  
P. K. SHUKLA

AbstractWe consider an adiabatic dusty plasma containing adiabatic inertialess electrons, adiabatic ions, and adiabatic negatively charged dust. The basic features of the dust–ion-acoustic (DIA) as well as the dust-acoustic (DA) solitary waves (SWs) in such an adiabatic dusty plasma are investigated using the reductive perturbation method, which is valid for small amplitude SWs, and by the pseudo-potential approach which is valid for arbitrary amplitude SWs. The combined effects of the adiabaticity of electrons/ions and negatively charged static/mobile dust on the basic features (polarity, speed, amplitude and width) of small as well as arbitrary amplitude DIA and DA SWs are examined explicitly. It is found that the combined effects of the adiabaticity of electrons/ions and negatively charged static/mobile dust 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 discussed briefly.


Author(s):  
P.K Shukla ◽  
L Stenflo

We present a multi-fluid theory for the Jeans instability accounting for an attractive force between two equally charged dust particles in a self-gravitating plasma. Our analyses which includes the electrostatic energy between two charged dust grains provides a possibility of resolving the ‘Jeans swindle’, in addition to obtaining a Jeans instability with a faster growth rate. The relevance of our investigation to the formation of planetesimals and collapse of interstellar clouds in star forming regions is discussed.


2021 ◽  
Author(s):  
Lina Hadid ◽  
Oleg Shebanits ◽  
Jan-Erik Wahlund ◽  
Michiko Morooka ◽  
Andrew Nagy ◽  
...  

<p>It is well known that in the magnetosphere of the outer planets (eg. Saturn, Jupiter, Neptune), even in the absence of an electric current, a polarization electric field develops as a consequence of charge separation in a plasma, providing a restoring force to maintain charge neutrality. It is also well established that certain regions of these planetary systems (ionosphere, icy moons, rings) are populated by significant amount of charged dust that play an important role in the physical and chemical processes in the surrounding plasma environment.<br>In the present work, we study the effect of the charged dust grains on the polarization electric field using Saturn’s F-ring region as a case study. We derive a general expression for E parallel to the magnetic field (E_para) and then using the Cassini RPWS/LP measurements we estimate for the first time in situ E_para close to Janus/Epimetheus ring during the F ring grazing orbits. We further demonstrate that the presence of charged dust,  as small as nanometers in size, can significantly influence the plasma transport processes, in particular the ambipolar diffusion along the magnetic field lines. We show that, close to the ring plane (Z <0.1 Rs), the dusty plasma amplifies E_para by at least one order of magnitude and reverses its direction. Such a reversal implies a confinement of the electrons above the equatorial plane. Furthermore, we show a clear correlation between the amplification of the ambipolar eletrostatic field and the ions and electrons number densities, that could be used in other dusty environments where in-situ measurements are not available yet (in our solar system or the interstellar medium).</p>


2008 ◽  
Vol 86 (8) ◽  
pp. 975-983 ◽  
Author(s):  
M Tribeche ◽  
S Younsi ◽  
T H Zerguini

A theoretical model is presented to show the existence, formation, and possible realization of large-amplitude dust-acoustic solitary potentials in electron-depleted hot dusty plasma with trapped ions. These nonlinear localized structures are self-consistent solutions of the Vlasov equation in which the ion response is non-Maxwellian due to the ion trapping in the large-amplitude plasma potentials. Emphasis is given to the role of the grain temperature. Interestingly, one finds that the effect of increasing the dust temperature is to restrict the domain of allowable Mach numbers. The latter enlarges when the relative amount of trapped ions is increased. Furthermore, the nonlinear potential shrinks and exhibits smaller depth and smaller width than the one involving cold dust grains. The strong localization of the dust particles becomes less pronounced when the dust temperature is increased. The results complement and provide new insights into previously published results on this problem and their relevance to space dusty plasmas is pointed out.PACS Nos.: 52.27.Lw; 52.35.Fp; 52.35.Sb; 52.35.Tc; 52.35.Mw


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