Modified Zakharov–Kuznetsov equation for a non-uniform electron–positron–ion magnetoplasma with kappa-distributed electrons

2015 ◽  
Vol 81 (5) ◽  
Author(s):  
Ali Ahmad ◽  
W. Masood
Keyword(s):  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
Low Frequency ◽  
Larmor Frequency ◽  
Magnetized Plasma ◽  
Intense Laser ◽  
Linear Dispersion ◽  
Electron Positron ◽  
Solitary Structures ◽  
Ion Acoustic

We investigate the low-frequency (by comparison with the ion Larmor frequency) electrostatic solitary structures in a spatially non-uniform electron–positron–ion (e–p–i) magnetoplasma with non-Maxwellian electrons. A linear dispersion relation for the obliquely propagating ion acoustic drift wave is derived and it is shown that the non-Maxwellian electron population modifies the dispersion characteristics of the wave under consideration. We also carry out a nonlinear analysis and derive the modified Zakharov–Kuznetsov (MZK) equation for the coupled drift acoustic wave in a non-uniform magnetized plasma. We highlight the differences between the MZK equation and its homogeneous counterpart. We also find the solution of the MZK equation using the tangent hyperbolic method. It is observed that the electron spectral index ${\it\kappa}$, positron concentration, and propagation angle ${\it\alpha}$ alter the structure of the ion acoustic drift solitary waves. The results obtained in this paper may be beneficial to understanding the propagation characteristics of electrostatic drift solitary structures in the interstellar medium and in laboratory experiments where electron–positron plasmas have recently been created by impinging ultra-intense laser pulses on a solid density target at the Lawrence Livermore National Laboratory (LLNL).

Ion-acoustic solitary structures at the acoustic speed in a collisionless magnetized nonthermal dusty plasma

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Debdatta Debnath ◽  
Anup Bandyopadhyay
Keyword(s):  
Double Layer ◽  
Negative Polarity ◽  
Critical Value ◽  
Magnetized Plasma ◽  
Double Layers ◽  
Nonthermal Electrons ◽  
Solitary Structures ◽  
Ion Acoustic ◽  
Density Of Electrons ◽  
Acoustic Speed

Abstract At the acoustic speed, we have investigated the existence of ion-acoustic solitary structures including double layers and supersolitons in a collisionless magnetized plasma consisting of negatively charged static dust grains, adiabatic warm ions, and nonthermal electrons. At the acoustic speed, for negative polarity, the system supports solitons, double layers, supersoliton structures after the formation of double layer, supersoliton structures without the formation of double layer, solitons after the formation of double layer whereas the system supports solitons and supersolitons without the formation of double layer for the case of positive polarity. But it is not possible to get the coexistence of solitary structures (including double layers and supersolitons) of opposite polarities. For negative polarity, we have observed an important transformation viz., soliton before the formation of double layer → double layer → supersoliton → soliton after the formation of double layer whereas for both positive and negative polarities, we have observed the transformation from solitons to supersolitons without the formation of double layer. There does not exist any negative (positive) potential solitary structures within 0 < μ < μ c (μ c < μ < 1) and the amplitude of the positive (negative) potential solitary structure decreases for increasing (decreasing) μ and the solitary structures of both polarities collapse at μ = μ c, where μ c is a critical value of μ, the ratio of the unperturbed number density of electrons to that of ions. Similarly there exists a critical value β e2 of the nonthermal parameter β e such that the solitons of both polarities collapse at β e = β e2.

Nonlinear ion acoustic excitations in relativistic degenerate, astrophysical electron–positron–ion plasmas

2013 ◽  
Vol 79 (5) ◽  
pp. 817-823 ◽  
Author(s):  
ATA-UR RAHMAN ◽  
S. ALI ◽  
A. MUSHTAQ ◽  
A. QAMAR
Keyword(s):  
Perturbation Technique ◽  
Collisionless Plasma ◽  
Plasma Parameters ◽  
Linear Dispersion ◽  
Electron Positron ◽  
Electrons And Positrons ◽  
Ion Acoustic ◽  
Astrophysical Objects ◽  
Collective Interactions ◽  
Acoustic Excitations

AbstractThe dynamics and propagation of ion acoustic (IA) waves are considered in an unmagnetized collisionless plasma, whose constituents are the relativistically degenerate electrons and positrons as well as the inertial cold ions. At a first step, a linear dispersion relation for IA waves is derived and analysed numerically. For nonlinear analysis, the reductive perturbation technique is used to derive a Korteweg–deVries equation, which admits a localized wave solution in the presence of relativistic degenerate electrons and positrons. It is shown that only compressive IA solitary waves can propagate, whose amplitude, width and phase velocity are significantly modified due to the positron concentration. The latter also strongly influences all the relativistic plasma parameters. Our present analysis is aimed to understand collective interactions in dense astrophysical objects, e.g. white dwarfs, where the lighter species electrons and positrons are taken as relativistically degenerate.

Drift wave instability in a radially bounded dusty magnetoplasma with parallel ion velocity shear

2012 ◽  
Vol 79 (1) ◽  
pp. 33-35
Author(s):  
P. K. SHUKLA ◽  
M. ROSENBERG
Keyword(s):  
Wave Equation ◽  
Fluid Model ◽  
Low Frequency ◽  
Velocity Shear ◽  
Charged Dust ◽  
Wave Instability ◽  
Linear Dispersion ◽  
Drift Wave ◽  
Ion Acoustic ◽  
Two Fluid Model

AbstractProperties of the coupled dust ion-acoustic drift wave instability in a radially bounded dusty magnetoplasma with an equilibrium sheared parallel ion (SPI) flow are investigated. By using the two-fluid model for the electrons and ions, a wave equation for the low-frequency coupled dust ion-acoustic drift waves in a bounded plasma with stationary charged dust grains is derived. The wave equation admits a linear dispersion relation, which exhibits that the radial boundary affects the growth rate of the coupled ion-acoustic drift wave instability which is excited by the SPI flow. The results should be relevant to dusty magnetoplasma experiments with an SPI flow.

scholarly journals High energy electrons, nuclear phenomena and heating in petawatt laser-solid experiments

1999 ◽  
Vol 17 (4) ◽  
pp. 773-783 ◽  
Author(s):  
T.E. COWAN ◽  
M.D. PERRY ◽  
M.H. KEY ◽  
T.R. DITMIRE ◽  
S.P. HATCHETT ◽  
...  
Keyword(s):  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
High Energy ◽  
Preliminary Evidence ◽  
Intense Laser ◽  
Photonuclear Reactions ◽  
High Energy Electrons ◽  
Preformed Plasma ◽  
Nuclear Processes ◽  
Laser Solid Interactions

The Petawatt laser at Lawrence Livermore National Laboratory (LLNL) has opened a new regime of laser matter interactions in which the quiver motion of plasma electrons is fully relativistic with energies extending well above the threshold for nuclear processes. In addition to ∼few MeV ponderomotive electrons produced in ultra intense laser-solid interactions, we have found a high energy component of electrons extending to ∼100 MeV apparently from relativistic selffocusing and plasma acceleration in the underdense preformed plasma. The generation of hard bremsstrahlung, photonuclear reactions, and preliminary evidence for positron-electron pair production will be discussed.

scholarly journals Amplification of magnetic fields by polaritonic flows in quantum pair plasmas

2007 ◽  
Vol 73 (3) ◽  
pp. 289-293 ◽  
Author(s):  
N. SHUKLA ◽  
P. K. SHUKLA ◽  
G. E. MORFILL
Keyword(s):  
Dispersion Relation ◽  
Magnetic Fields ◽  
Intense Laser ◽  
Linear Dispersion ◽  
Laser Plasma Interaction ◽  
Faraday’S Law ◽  
Electron Positron ◽  
Quantum Electron ◽  
Astrophysical Objects ◽  
Micromechanical Systems

AbstractIt is shown that equilibrium polaritonic flows can amplify magnetic fields in an ultra-cold quantum electron–positron/hole (polaritons) plasma. For this purpose, a linear dispersion relation has been derived by using the quantum generalized hydrodynamic equations for the polaritons, the Maxwell equation, and Faraday's law. The dispersion relation admits purely growing instabilities, the growth rates of which are proportional to the equilibrium streaming speeds of the polaritons. Possible applications of our work to the spontaneous excitation of magnetic fields and the associated cross-field transport of the polaritons in micromechanical systems, compact dense astrophysical objects (e.g. neutron stars), and intense laser–plasma interaction experiments are mentioned.

Ion-acoustic stable oscillations, solitary, periodic and shock waves in a quantum magnetized electron–positron–ion plasma

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ahmed Atteya ◽  
Mohamed A. El-Borie ◽  
Gamal D. Roston ◽  
Abdel-Aziz Samir El-Helbawy ◽  
Punam Kumari Prasad ◽  
...  
Keyword(s):  
Shock Waves ◽  
Wave Solution ◽  
Phase Plane ◽  
Intense Laser ◽  
Periodic Wave Solution ◽  
Phase Plane Analysis ◽  
Bohm Potential ◽  
And Shock Waves ◽  
Electron Positron ◽  
Ion Acoustic

Abstract Nonlinear stable oscillations, solitary, periodic and shock waves in electron–positron–ion (EPI) quantum plasma in the presence of an external static magnetic field are reported. The Korteweg-de Vries-Burgers (KdVB) equation is derived by the reductive perturbation technique (RPT). The wave solution gives shock waves depending on various parameters as quantum diffraction parameter (β), electron and positron Fermi temperatures, and densities of the system species. Amplitude, polarity, speed, and width of wave solutions are remarkably modified by species densities, kinematic viscosity, and the Bohm potential. Existence of stable oscillation of ion-acoustic waves (IAWs) is shown by using the concept of phase plane analysis. Stability of wave solution is analysed by examining the Bohm potential effect. In the absence of dissipation, phase plane of the considered plasma system is analysed to discuss the existence of periodic wave solution. The results of this study could be helpful for comprehension of the wave features in dense quantum plasmas, like white dwarfs, laboratory plasma as interaction experiments of intense laser-solid matter and microelectronic devices.

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