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Mehran Shahmansouri

Bio: Mehran Shahmansouri is an academic researcher from Arak University. The author has contributed to research in topics: Dusty plasma & Ion acoustic wave. The author has an hindex of 17, co-authored 74 publications receiving 799 citations.
Topics: Dusty plasma, Ion acoustic wave, Plasma, Electron, Ion


Papers
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Journal ArticleDOI
TL;DR: In this paper, nonlinear dust acoustic (DA) localized structures in two-suprathermal ion-temperature dusty plasma are studied in a pseudo-potential approach, where the electron number density is assumed to be sufficiently depleted owing to the electron attachment during the dust charging process.
Abstract: Nonlinear dust acoustic (DA) localized structures are studied in two-suprathermal ion-temperature dusty plasma. The electron number density is assumed to be sufficiently depleted owing to the electron attachment during the dust charging process, i.e. n e ≪n i . The DA solitary waves and double-layers are investigated based on the pseudo-potential approach. It is found that the ion suprathermality may affect the spatial patterns as well as the nature of the DA structures.

44 citations

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TL;DR: In this article, the effects of the obliqueness and nonextensive electrons are incorporated in the study of ion acoustic (IA) waves in a magnetized plasma and the propagation properties of two possible modes (in the linear regime) are investigated.
Abstract: The combined effects of the obliqueness and nonextensive electrons are incorporated in the study of ion acoustic (IA) waves in a magnetized plasma. The propagation properties of two possible modes (in the linear regime) are investigated. It is found that the electron nonextensivity decreases the phase velocities of both two modes. Also obliqueness leads to increase of separation between two modes. The nonlinear evolution of IA solitary waves is governed by an energy-like equation. The influence of electron nonextensivity, 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 IA soliton and its profile is significantly depended on the deviation of electrons from thermodynamic equilibrium and obliqueness. Interestingly, the present model supports compressive as well as rarefactive IA solitary waves. Our finding should elucidate the nonlinear electrostatic structures that propagate in astrophysical and cosmological plasma scenarios where nonextensive and magnetized plasma can exist; like instellar plasma stellar polytropes, solar neutrino problem, peculiar velocities of galaxy clusters, dark-matter halos, protoneutron stars, hadronic matter, quark-gluon plasma, and magnetosphere, etc.

42 citations

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TL;DR: In this article, the surface plasmon waves in a quantum plasma half-space were studied by considering the effects of exchange and correlation for the electrons, and it was found that the exchange-correlation effects significantly modified the behavior of surface ponsmon waves.
Abstract: We studied the surface plasmon waves in a quantum plasma half-space by considering the effects of exchange and correlation for the electrons. We used a quantum hydrodynamic approach, including the full set of Maxwell equations and considering two new quantities (measuring the exchange and correlation effects) in addition to the Fermi electron temperature and the quantum Bohm potential, to derive the dispersion relation for the surface plasmon waves. It was found that the exchange-correlation effects significantly modified the behavior of surface plasmon waves. We showed that the frequency of surface plasmon wave was down-shifted by the exchange-correlation effects. On the other hand, the quantum effects (including of the exchange-correlation effects and the quantum Bohm potential) was seen to cause an increase in the phase speed of surface plasmon waves. Our results can help to understand the propagation properties of surface waves in intense laser produced solid density plasmas and metallic plasmas.

39 citations

Journal ArticleDOI
TL;DR: In this paper, the existence and characteristics of DA waves in an electron-depleted dusty plasma with two-temperature ions are modeled by kappa distribution functions, and a three-dimensional cylindrical Kadomtsev-Petviashvili equation is derived by means of a reductive perturbation method.
Abstract: A theoretical investigation is carried out to study the existence and characteristics of propagation of dust-acoustic (DA) waves in an electron-depleted dusty plasma with two-temperature ions, which are modeled by kappa distribution functions. A three-dimensional cylindrical Kadomtsev-Petviashvili equation governing evolution of small but finite amplitude DA waves is derived by means of a reductive perturbation method. The influence of physical parameters on solitary wave structure is examined. Furthermore, the energy integral equation is used to study the existence domains of the localized structures. It is found that the present model can be employed to describe the existence of positive as well as negative polarity DA solitary waves by selecting special values for parameters of the system, e.g., superthermal index of cold and/or hot ions, cold to hot ion density ratio, and hot to cold ion temperature ratio. This model may be useful to understand the excitation of nonlinear DA waves in astrophysical objects.

35 citations

Journal ArticleDOI
TL;DR: In this paper, the oblique propagation of arbitrary dust-acoustic solitary waves in an electron depleted magnetized dusty plasma which consists of kappa distributed ions and negatively charged warm dust fluid is investigated.
Abstract: A theoretical investigation has been made on the oblique propagation of arbitrary dust-acoustic solitary waves in an electron depleted magnetized dusty plasma which consists of kappa distributed ions and negatively charged warm dust fluid. The electron number density is assumed to be sufficiently depleted owing to the electron attachment during the dust charging process, i.e., ne≪ni. The propagation properties of two possible modes (in the linear regime) are investigated. It is found that deviation of ions from thermodynamic equilibrium leads to a decrease of the phase velocity of both modes. A nonlinear pseudopotential approach is employed to derive an energy-like equation which admits to investigate the occurrence of stationary solitary wave solution for the propagation of arbitrary amplitude. The effects of superthermality, obliqueness, and external magnetic field on the existence domain and nature of these solitary waves are discussed. Only negative polarity of solitary waves is found to exist. It is ...

34 citations


Cited by
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Book
30 Apr 2000
TL;DR: In this article, the authors present a survey of charging mechanisms and experiments, including mass and size distributions, and other modes of charge, such as self-gravitation, self-charge, and fluxuating dust charges.
Abstract: Preface. 1. Plasmas and Dust. 2. Charging Mechanisms and Experiments. 3. Space Observations. 4. Multispecies Formalism and Waves. 5. Electrostatic Modes. 6. Electromagnetic Modes. 7. Fluctuating Dust Charges. 8. Self-Gravitation. 9. Mass and Size Distributions. 10. Other Modes. 11. Conclusions and Outlook. Bibliography. Index.

425 citations

Journal ArticleDOI
TL;DR: Symbolic computation on an observationally/experimentally-supported (2+1)-dimensional generalized variable-coefficient Kadomtsev-Petviashvili-Burgers-type equation is done, for certain dusty plasmas, relying on such plasma coefficient functions as the nonlinearity, dispersion, dusty-fluid-viscosity-dissipation, geometric-effect and diffraction/transverse-perturbation coefficients.

142 citations

01 Apr 1984
TL;DR: In this article, test particle simulations are used to investigate the perpendicular heating of ions at low altitudes by the electric fields associated with moving auroral arcs, and the rapid motion of small-scale structures in the arces is suggested as a source of low-energy conical ion distributions.
Abstract: Magnetized test ions are subjected to acceleration through a numerically simulated oblique double layer in order to determine whether they emerge with velocity vectors aligned with or oblique to the ambient magnetic field. A criterion for oblique alignment, depending on the double-layer parameters and on the external magnetization, is obtained. When it is applied to observed and theoretical auroral double layers, this criterion predicts that accelerated heavy ions will be substantially less magnetic field aligned than will accelerated hydrogen ions, thus suggesting auroral double layers as a source of high-energy ion conics. Test particle simulations are also used to investigate the perpendicular heating of ions at low altitudes by the electric fields associated with moving auroral arcs. The rapid motion of small-scale structures in the arces is suggested as a source of low-energy conical ion distributions, and the slow drifts of the entire arc forms are inferred to heat ionospheric ions.

120 citations

Posted Content
TL;DR: In this article, it was shown that spin relaxation close to the glass temperature of CuMn and AuFe spin glasses follows a generalised exponential function which explicitly introduces hierarchically constrained dynamics and macroscopic interactions.
Abstract: Spin relaxation close to the glass temperature of CuMn and AuFe spin glasses is shown, by neutron spin echo, to follow a generalised exponential function which explicitly introduces hierarchically constrained dynamics and macroscopic interactions. The interaction parameter is directly related to the normalised Tsallis non-extensive entropy parameter, q, and exhibits universal scaling with reduced temperature. At the glass temperature q=5/3 corresponding, within Tsallis' q-statistics, to a mathematically defined critical value for the onset of strong disorder and non-linear dynamics.

110 citations