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1.
Obliquely propagating altra-low-frequency dust-electromagnetic waves in a self-gravitating, warm, magnetized, two fluid dusty
plasma system have been investigated. Two special cases, namely, dust-Alfvén mode propagating parallel to the external magnetic
field and dustmagnetosonic mode propagating perpendicular to the external magnetic field have also been considered. It has
been shown that effects of self-gravitational field, dust fluid temperature, and obliqueness significantly modify the dispersion
properties of these ultra-low-frequency dust-electromagnetic modes. It is also found that in parallel propagating dust-Alfvén
mode these effects play no role, but in obliquely propagating dust-Alfvén mode or perpendicular propagating dust-magnetosonic
mode the effect of self-gravitational field plays destabilizing role whereas the effect of dust/ion fluid temperature plays
stabilizing role. 相似文献
2.
In consideration of adiabatic dust charge variation, the
combined effect of the external magnetized field and the dust
temperature on head-on collision of the three-dimensional dust
acoustic solitary waves is investigated. By using the extended
Poincar\'e--Lighthill--Kuo method, the phase shifts and the
trajectories of two solitons after the collision are obtained. The
effects of the magnitude and the obliqueness of the external
magnetic field and the dust temperature on the
solitary wave collisions are discussed in detail. 相似文献
3.
The instability of electrostatic wave in a magnetized dusty plasma with nonadiabatic dust charge fluctuation 总被引:2,自引:0,他引:2
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The effects of external magnetized field and nonadiabatic dust charge fluctuation on instability of wave incorporating the nonthermally distributed ions and the temperatures of ion and dust in dusty plasmas are investigated. A linear dispersion relation is obtained. The numerical results show that the external magnetized field, fast ions and nonadiabatic dust charge fluctuation have strong influence on the frequency and the damping of wave. 相似文献
4.
Filamentation phenomenon is one of the most important outcomes of applying a strong magnetic field to low-pressure plasmas and dusty plasmas. In this article, the variation of filamentation phenomenon with neutral gas pressure and plasma density will be investigated using numerical simulations. It will be shown through these simulations how the formation of the filamentary patterns in the magnetized plasma results in a localized electric field structure that strongly contributes to the properties of the filamentary patterns. Based on the results of the simulations, a theoretical model is derived that relates the width of the filamentary patterns to the plasma density. The model has been successfully employed to predict the width of the patterns emerging in various simulations of the magnetized plasma. 相似文献
5.
Effect of dust charge variation on dust—acoustic solitary waves in a magnetized two—ion—temperature dusty plasma
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The effect of dust charge variation on the dust-acoustic solitary structures is investigated in a warm magnetized two-ion-temperature dusty plasma consisting of a negatively and variably charged extremely massive dust fluid and ions of two different temperatures. It is shown that the dust charge variation as well as the presence of a second component of ions would modify the properties of the dust-acoustic solitary structures and may exite both dust-acoustic solitary holes (soliton waves with a density dip) and positive solitons (soliton waves with a density hump). 相似文献
6.
M. S. Bawa'aneh 《等离子体物理论文集》2003,43(7):447-455
Stimulated Brillouin backscattering (SBBS) from a magnetized homogeneous plasma is investigated. Effect of a dc–magnetic field on SBBS growth rate is obtained and compared with that for non–magnetized plasmas. Numerical calculations show an increase in the instability growth rate for small magnetic fields, then a decrease in the growth rate as the magnetic field increases till a cut–off field is reached, beyond which SBBS is brought to stability. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
7.
Effect of adiabatic variation of dust charges on dust acoustic solitary waves in magnetized dusty plasmas
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The effect of dust charging and the influence of its adiabatic variation on dust acoustic waves is investigated. By employing the reductive perturbation technique we derived a Zakharov-Kuznetsov (ZK) equation for small amplitude dust acoustic waves. We have analytically verified that there are only rarefactive solitary waves for this system. The instability region for one-dimensional solitary wave under transverse perturbations has also been obtained. The obliquely propagating solitary waves to the z-direction for the ZK equation are given in this paper as well. 相似文献
8.
9.
Propagation properties of dust-electron-acoustic waves in weakly magnetized dusty nonthermal plasmas
The linear and nonlinear properties of dust-electron acoustic waves (DEAWs) propagating in magnetized, collisionless, dusty plasma system containing inertial cold electrons, Maxwellian hot electrons, nonthermal ions, and arbitrarily (positively or negatively) charged stationary dust are investigated. The reductive perturbation technique is employed to reduce the basic set of fluid equations to the modified Korteweg-de Vries equation or Ostrovsky's equation, which governs the dynamics of small amplitude DEAWs in a weakly magnetized dusty nonthermal plasma. The approximate analytical as well as numerical solutions reveal that the basic characteristics of DEA nonlinear structures are found to be significantly modified by the key plasma configuration parameters. It is found that the leading compressive or rarefactive solitary wave structure separates from a trailing wave packet during a considerable time under the influence of magnetic field-induced Lorentz force. 相似文献
10.
Mangilal Choudhary Roman Bergert Sandra Moritz Slobodan Mitic Markus H. Thoma 《等离子体物理论文集》2021,61(1):e202000110
The collective dynamics of an annulus dusty plasma formed between a co-centric conducting (non-conducting) disk and ring configuration is studied in a strongly magnetized radiofrequency (rf) discharge. A superconducting electromagnet is used to introduce a homogeneous magnetic field to the dusty plasma medium. In the absence of the magnetic field, the dust grains exhibit thermal motion around their equilibrium position. The dust grains start to rotate in the anticlockwise direction with increasing magnetic field (B > 0.02 T ), and the constant value of the angular frequency at various strengths of the magnetic field confirms the rigid body rotation. The angular frequency of dust grains linearly increases up to a threshold magnetic field (B > 0.6 T ) and after that its value remains nearly constant in a certain range of magnetic field. Further increase in magnetic field (B > 1 T ) lowers the angular frequency. Low value of the angular frequency is expected by reducing the width of the annulus dusty plasma or the input rf power. The azimuthal ion drag force due to the magnetic field is assumed to be the energy source which drives the rotational motion. The resultant radial electric field in the presence of a magnetic field determines the direction of rotation. The variation of floating (plasma) potential across the annular region at given magnetic field explains the rotational properties of the annulus dusty plasma in the presence of a magnetic field. 相似文献
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13.
A possibility of self‐organization of magnetized four‐component dusty plasmas to double Beltrami (DB) state is explored. It is found that for a specific set of Beltrami parameters, the four‐component dusty plasma self‐organizes to DB state. The DB state characterized by two scale parameters may represent a paramagnetic or diamagnetic field structure. The impact of Beltrami parameters, charge and densities of dust grains on formation of self‐organized structures has also been investigated. This study has potential relevance to the formation of large‐scale structures in astrophysical plasmas. 相似文献
14.
The collective behaviour of two‐dimensional (2D) liquid dusty plasmas under perpendicular magnetic fields is studied using Langevin dynamic simulations. Based on the positions and velocities of the simulated dust particles, the dynamic parameters of intermediate scattering functions and probability distribution functions are calculated. It is found that, under different 2D liquid dusty plasma conditions, the motion of individual dust particles tends to be more super‐diffusive under stronger perpendicular magnetic fields, well consistent with the previous finding using a different diagnostic technique. 相似文献
15.
The Rayleigh ‐ Taylor (RT) instability is investigated analytically in an inhomogeneous plasma in an external magnetic field. For the case of two distinct fluid layers separated by a sharp boundary and for a fluid of a continuously varying density, RT dispersion relations have been obtained and analyzed. Stability criteria of the excited modes are disscussed with respect to the mode propagation relative to the applied magnetic field. The magnetic field is found to act as a stabilizer up to a threshold value that can be determined from the dispersion relation. 相似文献
16.
A.A. Mamun A.A. Gebreel 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,11(3):473-480
A theoretical investigation has been made of ultra-low-frequency dust-electrostatic and dust-electromagnetic modes, propagating
perpendicular to the external magnetic field, in a self-gravitating, warm, magnetized, two fluid dusty plasma system. It has
been shown that the effects of self-gravitational field and dust thermal pressure significantly modify the dispersion properties
of these ultra-low-frequency dust-modes. It is also found that under certain conditions, the self-gravitational effect can
destabilize these ultra-low-frequency dust-electrostatic and dust-electromagnetic modes. However, the effects of the external
magnetic field and dust and ion thermal pressures are found to play stabilizing role, i.e., these effects make these modes stable and counter the gravitational condensation of the dust grains. The implications of
these results to some space and astrophysical dusty plasma systems, especially, to planetary ring-systems and cometary tails,
are briefly mentioned.
Received 16 December 1999 相似文献
17.
18.
Effects of bi-kappa distributed electrons on dust-ion-acoustic shock waves in dusty superthermal plasmas
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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 investi- gated 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. 相似文献
19.
The stability of ion electrostatic waves with propagation vector nearly normal to a static magnetic field in a collisional plasma carrying a field-aligned current is investigated in the cold plasma approximation. 相似文献