Self-similar expansion of adiabatic electronegative dusty plasma

2017 ◽  
Vol 83 (6) ◽  
Author(s):  
M. Shahmansouri ◽  
A. Bemooni ◽  
A. A. Mamun

The self-similar expansion of an adiabatic electronegative dusty plasma (consisting of inertialess adiabatic electrons, inertialess adiabatic ions and inertial adiabatic negatively charged dust fluids) is theoretically investigated by employing the self-similar approach. It is found that the effects of the plasma adiabaticity (represented by the adiabatic index $\unicode[STIX]{x1D6FE}$) and dusty plasma parameters (determined by dust temperature and initial dust population) significantly modify the nature of the plasma expansion. The implications of our results are expected to play an important role in understanding the physics of the expansion of space and laboratory electronegative dusty 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.


2011 ◽  
Vol 227 ◽  
pp. 53-56 ◽  
Author(s):  
Djamila Bennaceur-Doumaz ◽  
Djemai Bara ◽  
Mourad Djebli

Based on the Gurevich distribution function, the effect of trapped electrons by the electrostatic potential rising during plasma expansion is investigated. The self similar approach is used to find the expanding profiles of density and velocity. The present work may be used to understand the salient features of the expansion of plasma produced by laser ablation.


Author(s):  
Shahid Ali ◽  
Yas Al-Hadeethi

Different plasma diagnostic methods are briefly discussed, and the framework of a test charge technique is effectively used as diagnostic tool for investigating interaction potentials in Lorentzian plasma, whose constituents are the superthermal electrons and ions with negatively charged dust grains. Applying the space-time Fourier transformations to the linearized coupled Vlasov-Poisson equations, a test charge potential is derived with a modified response function due to energetic ions and electrons. For a test charge moving much slower than the dust-thermal speed, there appears a short-range Debye-Hückel (DH) potential decaying exponentially with distance and a long-range far-field (FF) potential as the inverse cube of the distance from test charge. The FF potentials exhibit more localized shielding curves for low-Kappas, and smaller effective shielding length is observed in dusty plasma compared to electron-ion plasma. However, a wakefield (WF) potential is formed behind the test charge when it resonates with dust-acoustic oscillations, whereas a fast moving test charge leads to the Coulomb potential having no shielding around. It is revealed that superthermality and plasma parameters significantly alter the DH, FF, and WF potentials in space plasmas of Saturn’s E-ring, where power-law distributions can be used for energetic electrons and ions in contrast to Maxwellian dust grains.


Nukleonika ◽  
2016 ◽  
Vol 61 (2) ◽  
pp. 115-118
Author(s):  
Djamila Bennaceur-Doumaz ◽  
Djemai Bara

Abstract The expansion of semi-infinite laser produced plasma into vacuum is analyzed with a hydrodynamic model for cold ions assuming electrons modeled by a kappa-type distribution. Self-similar analytic expressions for the potential, velocity, and density of the plasma have been derived. It is shown that nonthermal energetic electrons have the role of accelerating the self-similar expansion.


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.


2021 ◽  
Author(s):  
Shuo Wang ◽  
Ning Zhang ◽  
Shun-xin Zhang ◽  
Miao Tian ◽  
Ya-wen Cai ◽  
...  

Abstract Using a dusty plasma ratchet, one can realize the rectification of charged dust particle in a plasma. To obtain the ratchet potential dominating the rectification, here, we perform quantitative simulations based on a two-dimensional fluid model of capacitively coupled plasma. Plasma parameters are firstly calculated in two typical cross sections of the dusty plasma ratchet which cut vertically the saw channel at different azimuthal positions. The balance positions of charged dust particle in the two cross sections then can be found exactly. The electric potentials at the two balance positions have different values. Using interpolation in term of a double-sine function from previous experimental measurement, an asymmetrical ratchet potential along the saw channel is finally obtained. The asymmetrical orientation of the ratchet potential depends on discharge conditions. Quantitative simulations further reproduce our previous experimental phenomena such as the rectification of dust particle in the dusty plasma ratchet.


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


2001 ◽  
Vol 18 (4) ◽  
pp. 374-383 ◽  
Author(s):  
N. F. Cramer ◽  
J. I. Sakai ◽  
S. V. Vladimirov

AbstractThe effects of charged dust on the steepening of the fields in nonlinear Alfvén waves in astrophysical weakly ionised plasmas are investigated. It is found that the formation of current singularities in the wave due to nonlinear ambipolar diffusion is strongly modified by the effects of the dust. The basic modes for propagation along the magnetic field in a dusty plasma are highly dispersive and split by the anisotropy of the magnetic field into two modes that are oppositely circularly polarised rather than linearly polarised. The right hand circularly polarised wave experiences a cutoff due to the presence of the dust. We derive nonlinear fluid equations describing the dusty plasma, and make approximations for strong coupling of the dust to the neutrals, and for stationary dust. Numerical solution of the equations shows that a nonlinear wave with sharp current features due to ambipolar diffusion involves a rotation of the wave magnetic field about the direction of propagation, and an oscillation of the field components, due to the mode splitting effects of the dust. This is in contrast to the dust-free case, where the sharp reversal of the transverse magnetic field component occurs in a single plane.


Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3846
Author(s):  
Mikhail Salnikov ◽  
Alexander Fedoseev ◽  
Gennadiy Sukhinin

The formation of a 1D chain-like structure of dust particles in a low-temperature argon plasma was studied. A new numerical model for calculation of the self-consistent spatial distribution of plasma parameters around a chain of dust particles was presented. The model described the motion of positively charged ions in the electric potential of several negatively charged dust particles, taking into account the action of an external electric field. The main advantage of the model was that the charges of the dust particles and the interparticle distances were determined self-consistently. As a result of numerical simulations, the dependencies of the spatial distributions of the plasma parameters (the densities of electrons and ions and the self-consistent electric potential) near the dust particles chain on the strength of the external electric field, an external force acted on the last particle, and the mean free path of the ions was determined. The obtained results made it possible to describe the process of the formation of chain-like structures of dust particles in discharge plasma.


Sign in / Sign up

Export Citation Format

Share Document