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Ioannis Kourakis - One of the best experts on this subject based on the ideXlab platform.
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modulational instability of dust acoustic Waves in dusty plasmas modulation obliqueness background ion nonthermality and dust charging effects
Physics of Plasmas, 2006Co-Authors: W F Eltaibany, Ioannis KourakisAbstract:The oblique modulational instability of dust acoustic (DA) Waves in an unmagnetized warm dusty plasma with nonthermal ions, taking into account dust grain charge variation (charging), is investigated. A nonlinear Schrodinger-type equation governing the slow modulation of the Wave amplitude is derived. The effects of dust temperature, dust charge variation, ion deviation from Maxwellian equilibrium (nonthermality) and constituent species’ concentration on the modulational instability of DA Waves are examined. It is found that these parameters modify significantly the oblique modulational instability domain in the k-θ plane. Explicit expressions for the instability rate and threshold have been obtained in terms of the dispersion laws of the system. The possibility and conditions for the existence of different types of localized excitations are also discussed. The findings of this investigation may be useful in understanding the stable Electrostatic Wave packet acceleration mechanisms close to the Moon, and ...
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modulational instability of dust acoustic Waves in dusty plasmas modulation obliqueness background ion nonthermality and dust charging effects
Physics of Plasmas, 2006Co-Authors: W F Eltaibany, Ioannis KourakisAbstract:The oblique modulational instability of dust acoustic (DA) Waves in an unmagnetized warm dusty plasma with nonthermal ions, taking into account dust grain charge variation (charging), is investigated. A nonlinear Schrodinger-type equation governing the slow modulation of the Wave amplitude is derived. The effects of dust temperature, dust charge variation, ion deviation from Maxwellian equilibrium (nonthermality) and constituent species’ concentration on the modulational instability of DA Waves are examined. It is found that these parameters modify significantly the oblique modulational instability domain in the k-θ plane. Explicit expressions for the instability rate and threshold have been obtained in terms of the dispersion laws of the system. The possibility and conditions for the existence of different types of localized excitations are also discussed. The findings of this investigation may be useful in understanding the stable Electrostatic Wave packet acceleration mechanisms close to the Moon, and ...
A P Misra - One of the best experts on this subject based on the ideXlab platform.
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nonlinear landau damping and modulation of Electrostatic Waves in a nonextensive electron positron pair plasma
Physical Review E, 2015Co-Authors: Debjani Chatterjee, A P MisraAbstract:The nonlinear theory of amplitude modulation of Electrostatic Wave envelopes in a collisionless electron-positron (EP) pair plasma is studied by using a set of Vlasov-Poisson equations in the context of Tsallis' q-nonextensive statistics. In particular, the previous linear theory of Langmuir oscillations in EP plasmas [Saberian and Esfandyari-Kalejahi, Phys. Rev. E 87, 053112 (2013)] is rectified and modified. Applying the multiple scale technique (MST), it is shown that the evolution of Electrostatic Wave envelopes is governed by a nonlinear Schrodinger (NLS) equation with a nonlocal nonlinear term ∝P∫|ϕ(ξ',τ)|(2)dξ'ϕ/(ξ-ξ') [where P denotes the Cauchy principal value, ϕ is the small-amplitude Electrostatic (complex) potential, and ξ and τ are the stretched coordinates in MST], which appears due to the Wave-particle resonance. It is found that a subregion 1/3
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modulational instability and nonlinear evolution of two dimensional Electrostatic Wave packets in ultra relativistic degenerate dense plasmas
Physics of Plasmas, 2011Co-Authors: A P Misra, P K ShuklaAbstract:We consider the nonlinear propagation of Electrostatic Wave packets in an ultra-relativistic (UR) degenerate dense electron–ion plasma, whose dynamics is governed by the nonlocal two-dimensional nonlinear Schrodinger-like equations. The coupled set of equations is then used to study the modulational instability (MI) of a uniform Wave train to an infinitesimal perturbation of multidimensional form. The condition for the MI is obtained, and it is shown that the nondimensional parameter, β∝λCn01/3 (where λC is the reduced Compton Wavelength and n0 is the particle number density) associated with the UR pressure of degenerate electrons, shifts the stable (unstable) regions at n0~1030cm-3 to unstable (stable) ones at higher densities, i.e., n0>7×1033. It is also found that the higher the values of n0, the lower is the growth rate of MI with cut-offs at lower Wave numbers of modulation. Furthermore, the dynamical evolution of the Wave packets is studied numerically. We show that either they disperse away or the...
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modulational instability and nonlinear evolution of two dimensional Electrostatic Wave packets in ultra relativistic degenerate dense plasmas
arXiv: Plasma Physics, 2010Co-Authors: A P Misra, P K ShuklaAbstract:We consider the nonlinear propagation of Electrostatic Wave packets in an ultra-relativistic (UR) degenerate dense electron-ion plasma, whose dynamics is governed by the nonlocal two-dimensional nonlinear Schr{\"o}dinger-like equations. The coupled set of equations are then used to study the modulational instability (MI) of a uniform Wave train to an infinitesimal perturbation of multi-dimensional form. The condition for the MI is obtained, and it is shown that the nondimensional parameter, $\beta\propto\lambda_C n_0^{1/3}$ (where $\lambda_C$ is the reduced Compton Wavelength and $n_0$ is the particle number density), associated with the UR pressure of degenerate electrons, shifts the stable (unstable) regions at $n_{0}\sim10^{30}$ cm$^{-3}$ to unstable (stable) ones at higher densities, i.e. $n_{0}\gtrsim7\times10^{33}$. It is also found that {the} higher the values of $n_{0}$, the lower is the growth rate of MI with cut-offs at lower Wave numbers of modulation. Furthermore, the dynamical evolution of the Wave packets is studied numerically. We show that either they disperse away or they blowup in a finite time, when the Wave action is below or above the threshold. The results could be useful for understanding the properties of modulated Wave packets and their multi-dimensional evolution in UR degenerate dense plasmas, such as those in the interior of white dwarfs {and/or} pre-Supernova stars.
W F Eltaibany - One of the best experts on this subject based on the ideXlab platform.
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modulational instability of dust acoustic Waves in dusty plasmas modulation obliqueness background ion nonthermality and dust charging effects
Physics of Plasmas, 2006Co-Authors: W F Eltaibany, Ioannis KourakisAbstract:The oblique modulational instability of dust acoustic (DA) Waves in an unmagnetized warm dusty plasma with nonthermal ions, taking into account dust grain charge variation (charging), is investigated. A nonlinear Schrodinger-type equation governing the slow modulation of the Wave amplitude is derived. The effects of dust temperature, dust charge variation, ion deviation from Maxwellian equilibrium (nonthermality) and constituent species’ concentration on the modulational instability of DA Waves are examined. It is found that these parameters modify significantly the oblique modulational instability domain in the k-θ plane. Explicit expressions for the instability rate and threshold have been obtained in terms of the dispersion laws of the system. The possibility and conditions for the existence of different types of localized excitations are also discussed. The findings of this investigation may be useful in understanding the stable Electrostatic Wave packet acceleration mechanisms close to the Moon, and ...
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modulational instability of dust acoustic Waves in dusty plasmas modulation obliqueness background ion nonthermality and dust charging effects
Physics of Plasmas, 2006Co-Authors: W F Eltaibany, Ioannis KourakisAbstract:The oblique modulational instability of dust acoustic (DA) Waves in an unmagnetized warm dusty plasma with nonthermal ions, taking into account dust grain charge variation (charging), is investigated. A nonlinear Schrodinger-type equation governing the slow modulation of the Wave amplitude is derived. The effects of dust temperature, dust charge variation, ion deviation from Maxwellian equilibrium (nonthermality) and constituent species’ concentration on the modulational instability of DA Waves are examined. It is found that these parameters modify significantly the oblique modulational instability domain in the k-θ plane. Explicit expressions for the instability rate and threshold have been obtained in terms of the dispersion laws of the system. The possibility and conditions for the existence of different types of localized excitations are also discussed. The findings of this investigation may be useful in understanding the stable Electrostatic Wave packet acceleration mechanisms close to the Moon, and ...
P K Shukla - One of the best experts on this subject based on the ideXlab platform.
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modulational instability and nonlinear evolution of two dimensional Electrostatic Wave packets in ultra relativistic degenerate dense plasmas
Physics of Plasmas, 2011Co-Authors: A P Misra, P K ShuklaAbstract:We consider the nonlinear propagation of Electrostatic Wave packets in an ultra-relativistic (UR) degenerate dense electron–ion plasma, whose dynamics is governed by the nonlocal two-dimensional nonlinear Schrodinger-like equations. The coupled set of equations is then used to study the modulational instability (MI) of a uniform Wave train to an infinitesimal perturbation of multidimensional form. The condition for the MI is obtained, and it is shown that the nondimensional parameter, β∝λCn01/3 (where λC is the reduced Compton Wavelength and n0 is the particle number density) associated with the UR pressure of degenerate electrons, shifts the stable (unstable) regions at n0~1030cm-3 to unstable (stable) ones at higher densities, i.e., n0>7×1033. It is also found that the higher the values of n0, the lower is the growth rate of MI with cut-offs at lower Wave numbers of modulation. Furthermore, the dynamical evolution of the Wave packets is studied numerically. We show that either they disperse away or the...
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modulational instability and nonlinear evolution of two dimensional Electrostatic Wave packets in ultra relativistic degenerate dense plasmas
arXiv: Plasma Physics, 2010Co-Authors: A P Misra, P K ShuklaAbstract:We consider the nonlinear propagation of Electrostatic Wave packets in an ultra-relativistic (UR) degenerate dense electron-ion plasma, whose dynamics is governed by the nonlocal two-dimensional nonlinear Schr{\"o}dinger-like equations. The coupled set of equations are then used to study the modulational instability (MI) of a uniform Wave train to an infinitesimal perturbation of multi-dimensional form. The condition for the MI is obtained, and it is shown that the nondimensional parameter, $\beta\propto\lambda_C n_0^{1/3}$ (where $\lambda_C$ is the reduced Compton Wavelength and $n_0$ is the particle number density), associated with the UR pressure of degenerate electrons, shifts the stable (unstable) regions at $n_{0}\sim10^{30}$ cm$^{-3}$ to unstable (stable) ones at higher densities, i.e. $n_{0}\gtrsim7\times10^{33}$. It is also found that {the} higher the values of $n_{0}$, the lower is the growth rate of MI with cut-offs at lower Wave numbers of modulation. Furthermore, the dynamical evolution of the Wave packets is studied numerically. We show that either they disperse away or they blowup in a finite time, when the Wave action is below or above the threshold. The results could be useful for understanding the properties of modulated Wave packets and their multi-dimensional evolution in UR degenerate dense plasmas, such as those in the interior of white dwarfs {and/or} pre-Supernova stars.
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low frequency Electrostatic Wave in a metallic electron hole ion plasma with nanoparticles
Journal of Plasma Physics, 2009Co-Authors: P K Shukla, G E MorfillAbstract:We investigate die dispersion property of a, low-frequency, Electrostatic Wave in a dense metallic electron-hole-ion plasma with nanoparticles. The latter are charged due to the Held emission, and ...
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phase speed of Electrostatic Waves the critical parameter for efficient electron surfing acceleration
arXiv: Astrophysics, 2006Co-Authors: Mark E Dieckmann, N J Sircombe, M Parviainen, P K Shukla, R O DendyAbstract:Particle acceleration by means of non-linear plasma Wave interactions is of great topical interest. Accordingly, in this paper we focus on the electron surfing process. Self-consistent kinetic simulations, using both relativistic Vlasov and PIC (Particle In Cell) approaches, show here that electrons can be accelerated to highly relativistic energies (up to 100 m_e c^2) if the phase speed of the Electrostatic Wave is mildly relativistic (0.6c to 0.9c for the magnetic field strengths considered). The acceleration is strong because of relativistic stabilisation of the nonlinearly saturated Electrostatic Wave, seen in both relativistic Vlasov and PIC simulations. An inverse power law momentum distribution can arise for the most strongly accelerated electrons. These results are of relevance to observed rapid changes in the radio synchrotron emission intensities from microquasars, gamma ray bursts and other astrophysical objects that require rapid acceleration mechanisms for electrons.
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dust ion acoustic Wave
Physica Scripta, 1992Co-Authors: P K Shukla, V P SilinAbstract:The existence of a new low-frequency Electrostatic Wave in an unmagnetized collisionless dusty plasma is pointed out.
Xinyi Gao - One of the best experts on this subject based on the ideXlab platform.
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mathematical view with observational experimental consideration on certain 2 1 dimensional Waves in the cosmic laboratory dusty plasmas
Applied Mathematics Letters, 2019Co-Authors: Xinyi GaoAbstract:Abstract Plasmas are believed to be possibly the most abundant form of ordinary matter in the Universe, supporting a variety of the Wave phenomena, while a dusty plasma is of interest as a non-Hamiltonian system of interacting particles. In this Letter, symbolic computation on an observationally/experimentally-supported (2+1)-dimensional generalized variable-coefficient Kadomtsev-Petviashvili-Burgers-type equation is done, for certain dust-acoustic, electron-acoustic, positron-acoustic, magneto-acoustic, dust-magneto-acoustic, ion-acoustic, dust-ion-acoustic and/or quantum-dust-ion-acoustic Waves in one of the cosmic/laboratory dusty plasmas. Auto-Backlund transformation and families of the solitonic solutions are obtained, for the Electrostatic Wave potential, perturbation of the magnitude of the magnetic field, fluctuation of electron or ion density, or radial-direction component of the velocity of ions or dust particles, relying on such plasma coefficient functions as the nonlinearity, dispersion, dusty-fluid-viscosity/Burgers-dissipation, geometric-effect and diffraction/transverse-perturbation coefficients. Shock structures presented in this Letter are very close to the experimental results previously reported. Future plasma observations/experiments might verify some other effects offered by our analytic results with respect to those plasma coefficient functions.
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variety of the cosmic plasmas general variable coefficient korteweg de vries burgers equation with experimental observational support
EPL, 2015Co-Authors: Xinyi GaoAbstract:Plasmas are known as the most abundant form of matter in the Universe. Nowadays, with respect to the cosmic plasmas, considerable efforts have been put into investigating the experimentally relevant Korteweg-de Vries (KdV)-Burgers–type equations. In this letter, with plenty of experimental/observational support presented, symbolic computation on a general variable-coefficient KdV-Burgers equation is performed, which covers the models for a variety of the cosmic plasmas. An auto-Backlund transformation is constructed out, along with two families of the analytic solitonic solutions, for the Electrostatic Wave potential, perturbation of the magnitude of the magnetic field, fluctuation of electron or ion density, or radial-direction component of the velocity of ions or dust particles. Both our auto-Backlund transformation and solitonic solutions depend on the cosmic-plasma parameters by way of the nonlinearity, dispersion, dissipation and geometric-effect coefficient functions, as to the ion-acoustic, magnetoacoustic, electron-acoustic, positron-acoustic, dust-acoustic and quantum dust-ion-acoustic Waves. The shock structures from our analytic investigation agree well with to those experimentally reported. Certain effects of a cosmic-plasma system, described by such variable coefficients, might be detected by the future plasma experiments/observations.