skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Effects of nonextensivity on the electron-acoustic solitary structures in a magnetized electron−positron−ion plasma

Abstract

Obliquely propagating electron-acoustic solitary waves (EASWs) in a magnetized electron−positron−ion plasma (containing nonextensive hot electrons and positrons, inertial cold electrons, and immobile positive ions) are precisely investigated by deriving the Zakharov–Kuznetsov equation. It is found that the basic features (viz. polarity, amplitude, width, phase speed, etc.) of the EASWs are significantly modified by the effects of the external magnetic field, obliqueness of the system, nonextensivity of hot positrons and electrons, ratio of the hot electron temperature to the hot positron temperature, and ratio of the cold electron number density to the hot positron number density. The findings of our results can be employed in understanding the localized electrostatic structures and the characteristics of EASWs in various astrophysical plasmas.

Authors:
; ; ;  [1]
  1. Jahangirnagar University, Department of Physics (Bangladesh)
Publication Date:
OSTI Identifier:
22614092
Resource Type:
Journal Article
Resource Relation:
Journal Name: Plasma Physics Reports; Journal Volume: 42; Journal Issue: 8; Other Information: Copyright (c) 2016 Pleiades Publishing, Ltd.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; AMPLITUDES; ASTROPHYSICS; CATIONS; ELECTRON DENSITY; ELECTRON TEMPERATURE; ELECTRONS; ELECTROSTATICS; EQUATIONS; ION ACOUSTIC WAVES; MAGNETIC FIELDS; PHASE VELOCITY; PLASMA; POSITRONS; WAVE PROPAGATION

Citation Formats

Rafat, A., E-mail: rafat.plasma@gmail.com, Rahman, M. M., Alam, M. S., and Mamun, A. A.. Effects of nonextensivity on the electron-acoustic solitary structures in a magnetized electron−positron−ion plasma. United States: N. p., 2016. Web. doi:10.1134/S1063780X16080092.
Rafat, A., E-mail: rafat.plasma@gmail.com, Rahman, M. M., Alam, M. S., & Mamun, A. A.. Effects of nonextensivity on the electron-acoustic solitary structures in a magnetized electron−positron−ion plasma. United States. doi:10.1134/S1063780X16080092.
Rafat, A., E-mail: rafat.plasma@gmail.com, Rahman, M. M., Alam, M. S., and Mamun, A. A.. 2016. "Effects of nonextensivity on the electron-acoustic solitary structures in a magnetized electron−positron−ion plasma". United States. doi:10.1134/S1063780X16080092.
@article{osti_22614092,
title = {Effects of nonextensivity on the electron-acoustic solitary structures in a magnetized electron−positron−ion plasma},
author = {Rafat, A., E-mail: rafat.plasma@gmail.com and Rahman, M. M. and Alam, M. S. and Mamun, A. A.},
abstractNote = {Obliquely propagating electron-acoustic solitary waves (EASWs) in a magnetized electron−positron−ion plasma (containing nonextensive hot electrons and positrons, inertial cold electrons, and immobile positive ions) are precisely investigated by deriving the Zakharov–Kuznetsov equation. It is found that the basic features (viz. polarity, amplitude, width, phase speed, etc.) of the EASWs are significantly modified by the effects of the external magnetic field, obliqueness of the system, nonextensivity of hot positrons and electrons, ratio of the hot electron temperature to the hot positron temperature, and ratio of the cold electron number density to the hot positron number density. The findings of our results can be employed in understanding the localized electrostatic structures and the characteristics of EASWs in various astrophysical plasmas.},
doi = {10.1134/S1063780X16080092},
journal = {Plasma Physics Reports},
number = 8,
volume = 42,
place = {United States},
year = 2016,
month = 8
}
  • Ion-acoustic (IA) solitary waves are investigated in a magnetized three-component plasma consisting of cold ions, isothermal hot electrons, and positrons. The basic set of fluid equations is reduced to the Korteweg de Vries equation using the standard reductive perturbation (multiple-scale) technique. Theoretical and numerical analyses confirm significant effects of the presence of positrons and the dependence of the electron to positron temperature ratio on the amplitude and the width of IA solitary waves. It is shown that the rarefactive and compressive IA solitary excitations can propagate when the propagation angle {theta} satisfies 0{<=}{theta}<{pi}/2 and {pi}/2<{theta}{<=}{pi}, respectively. Also, it is remarkedmore » that the amplitude of the rarefactive and compressive IA solitary excitations is not affected by the magnitude of external magnetic field B{sub 0}, whereas their width depends strictly on B{sub 0}. The numerical analysis has been done based on the typical numerical data from a pulsar magnetosphere.« less
  • The purpose of this work is to investigate the linear and nonlinear properties of the ion-acoustic waves (IAW), propagating obliquely to an external magnetic field in a weakly relativistic, rotating, and magnetized electron-positron-ion plasma. The Zakharov-Kuznetsov equation is derived by employing the reductive perturbation technique for this wave in the nonlinear regime. This equation admits the solitary wave solution. The amplitude and width of this solitary wave have been discussed with the effects of obliqueness, relativity, ion temperature, positron concentration, magnetic field, and rotation of the plasma and it is observed that for IAW these parameters affect the propagation propertiesmore » of solitary waves and these plasmas behave differently from the simple electron-ion plasmas. Likewise, the current density and electric field of these waves are investigated for their dependence on the above-mentioned parameters.« less
  • The properties of obliquely propagating ion-acoustic solitary waves in the presence of ambient magnetic field have been investigated theoretically in an electron-positron-ion nonthermal plasma. The plasma nonthermality is introduced via the q-nonextensive distribution of electrons and positrons. The Korteweg-de Vries (K-dV) and modified K-dV (mK-dV) equations are derived by adopting reductive perturbation method. The solution of K-dV and modified K-dV equation, which describes the solitary wave characteristics in the long wavelength limit, is obtained by steady state approach. It is seen that the electron and positron nonextensivity and external magnetic field (obliqueness) have significant effects on the characteristics of solitarymore » waves. A critical value of nonextensivity is found for which solitary structures transit from positive to negative potential. The findings of this investigation may be used in understanding the wave propagation in laboratory and space plasmas where static external magnetic field is present.« less
  • The nonlinear propagation of dust-acoustic (DA) waves in an obliquely propagating magnetized dusty plasma, containing nonextensively distributed electrons of distinct temperatures (namely lower and higher temperature nonextensive electrons), negatively charged mobile dust grains, and Maxwellian ions, is rigorously studied and analyzed by deriving the Zakharov-Kuznetsov equation. It is found that the characteristics of the DA solitary waves (DASWs) are significantly modified by the external magnetic field, obliqueness of the system, nonextensivity of the electrons, electron temperature-ratios, and the respective number densities of two species of electrons. The results obtained from this analysis can be employed in understanding and treating themore » structures and the characteristics of DASWs both in laboratory and astrophysical plasma system.« less
  • The basic features of obliquely propagating electron-acoustic (EA) solitary waves and their multidimensional instability in a magnetized plasma containing cold electrons, hot electrons obeying a vortexlike distribution, and stationary ions have been theoretically investigated by the reductive perturbation method and small-k perturbation expansion technique. The combined effects of external magnetic field (obliqueness) and trapped electron distribution, which are found to significantly modify the basic properties (amplitude and width) of small but finite-amplitude EA solitary waves, are explicitly examined. It is also found that the instability criterion and the growth rate are significantly modified by the external magnetic field and themore » propagation directions of both the nonlinear waves and their perturbation modes. The implications of our results in space plasmas are briefly discussed.« less