Compressive and rarefactive solitary structures of coupled kinetic Alfven-acoustic waves in non-Maxwellian space plasmas

2019 ◽  
Vol 26 (9) ◽  
pp. 092114 ◽  
Author(s):  
Saba Khalid ◽  
M. N. S. Qureshi ◽  
W. Masood
Keyword(s):  
Acoustic Waves ◽  
Space Plasmas ◽  
Solitary Structures

scholarly journals Dispersive MHD waves and alfvenons in charge non-neutral plasmas

2008 ◽  
Vol 15 (4) ◽  
pp. 681-693 ◽  
Author(s):  
K. Stasiewicz ◽  
J. Ekeberg
Keyword(s):  
Soliton Solutions ◽  
Theoretical Models ◽  
Mhd Waves ◽  
Space Plasmas ◽  
Charge Effects ◽  
Novel Technique ◽  
Solitary Structures ◽  
Spatial Dimensions ◽  
Electric Potentials ◽  
Linear And Nonlinear

Abstract. Dispersive properties of linear and nonlinear MHD waves, including shear, kinetic, electron inertial Alfvén, and slow and fast magnetosonic waves are analyzed using both analytical expansions and a novel technique of dispersion diagrams. The analysis is extended to explicitly include space charge effects in non-neutral plasmas. Nonlinear soliton solutions, here called alfvenons, are found to represent either convergent or divergent electric field structures with electric potentials and spatial dimensions similar to those observed by satellites in auroral regions. Similar solitary structures are postulated to be created in the solar corona, where fast alfvenons can provide acceleration of electrons to hundreds of keV during flares. Slow alfvenons driven by chromospheric convection produce positive potentials that can account for the acceleration of solar wind ions to 300–800 km/s. New results are discussed in the context of observations and other theoretical models for nonlinear Alfvén waves in space plasmas.

scholarly journals Collision-less shocks and solitons in dense laser-produced Fermi plasma

2020 ◽  
Vol 38 (1) ◽  
pp. 25-38
Author(s):  
J. Goswami ◽  
S. Chandra ◽  
J. Sarkar ◽  
S. Chaudhuri ◽  
B. Ghosh
Keyword(s):  
Acoustic Waves ◽  
Perturbation Technique ◽  
Reductive Perturbation Method ◽  
Viscous Force ◽  
Quantum Plasma ◽  
Linear Dispersion ◽  
Laser Plasma Interaction ◽  
Reductive Perturbation ◽  
Solitary Structures ◽  
Electron Acoustic

AbstractThe theoretical investigation of shocks and solitary structures in a dense quantum plasma containing electrons at finite temperature, nondegenerate cold electrons, and stationary ions has been carried out. A linear dispersion relation is derived for the corresponding electron acoustic waves. The solitary structures of small nonlinearity have been studied by using the standard reductive perturbation method. We have considered collisions to be absent, and the shocks arise out of viscous force. Furthermore, with the help of a standard reductive perturbation technique, a KdV–Burger equation has been derived and analyzed numerically. Under limiting cases, we have also obtained the KdV solitary profiles and studied the parametric dependence. The results are important in explaining the many phenomena of the laser–plasma interaction of dense plasma showing quantum effects.

Nonlinear electron-acoustic waves in a multi-species plasma

1980 ◽  
Vol 24 (1) ◽  
pp. 169-180 ◽  
Author(s):  
B. Buti
Keyword(s):  
Solitary Waves ◽  
Acoustic Waves ◽  
Large Amplitude ◽  
Space Plasmas ◽  
Strongly Nonlinear ◽  
Electron Acoustic Waves ◽  
Electron Acoustic ◽  
Ion Species

Propagation of electron-acoustic waves in a strongly nonlinear magnetoplasma with two ion species is investigated. The presence of the second ion component affects the dynamics of these solitary waves in a variety of ways. Besides solitons, supersonic holes (density depressions) are produced by sufficiently large- amplitude perturbations. Heavier and hotter ions are more favourable to the holes. Applications of the present investigations to space plasmas are pointed out.

scholarly journals Dromion solutions for nonlinear electron acoustic waves in space plasmas

2002 ◽  
Vol 9 (5/6) ◽  
pp. 463-475 ◽  
Author(s):  
S. S. Ghosh ◽  
A. Sen ◽  
G. S. Lakhina
Keyword(s):  
Acoustic Waves ◽  
Nonlinear Evolution ◽  
Two Dimensions ◽  
Space Plasmas ◽  
Ion Temperature ◽  
Polar Cap ◽  
Localized Solutions ◽  
Electron Acoustic Waves ◽  
Electron Acoustic

Abstract. Recent high resolution measurements of POLAR and FAST satellites have revealed two-dimensional coherent structures in the polar cap boundary layer (PCBL) region. Since the ion temperature is often observed to be greater than the electron temperature in this region, electron acoustic waves can exist as a normal mode of the plasma system. It is shown that the nonlinear evolution of such waves can be modelled by the coupled Davey-Stewartson I equations. These equations, which are a generalization of the nonlinear Schrödinger equation to two dimensions, admit exponentially localized solutions called dromions. A detailed parametric characterization of the regions of existence of such solutions is presented in the context of the PCBL region.

Theoretical properties of offset bipolar electric field solitary structures in space plasmas

2010 ◽  
Vol 45 (10) ◽  
pp. 1219-1223
Author(s):  
M.N.S. Qureshi ◽  
Jiankui Shi ◽  
Klaus Torkar ◽  
Zhenxing Liu
Keyword(s):  
Electric Field ◽  
Space Plasmas ◽  
Solitary Structures

Finite amplitude solitary structures of coupled kinetic Alfven-acoustic waves in dense plasmas

2014 ◽  
Vol 355 (2) ◽  
pp. 225-232 ◽  
Author(s):  
A. Sabeen ◽  
H. A. Shah ◽  
W. Masood ◽  
M. N. S. Qureshi
Keyword(s):  
Acoustic Waves ◽  
Finite Amplitude ◽  
Dense Plasmas ◽  
Solitary Structures

Damping of nonlinear magneto-acoustic waves

1978 ◽  
Vol 20 (1) ◽  
pp. 125-136 ◽  
Author(s):  
G. L. Kalra ◽  
V. B. Bhatia
Keyword(s):  
Electrical Conductivity ◽  
Numerical Investigation ◽  
Acoustic Waves ◽  
Finite Amplitude ◽  
Turbulent Plasma ◽  
Mhd Equations ◽  
Space Plasmas ◽  
Fast Mode ◽  
Mode Propagation

Nonlinear magneto-acoustic waves in a turbulent plasma are simulated by collisional MHD equations. Damping of these waves due to electrical conductivity arising from micro-instabilities and collisional viscosity are analyzed. Numerical investigation of competing effects due to non-linearity and dissipation has been carried out. It is found that finite amplitude perturbation leads to the formation of a shock in both the slow and the fast mode propagation. Collisional viscosity plays an important role in the damping of nonlinear magneto-acoustic waves in the astrophysical and space plasmas.

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