Nonlinear Propagation Of Electron-acoustic Waves Research Articles

Cylindrical and spherical solitary waves in an electron-acoustic plasma with vortex electron distribution

We consider the nonlinear propagation of electron-acoustic waves in a plasma composed of a cold electron fluid, hot electrons obeying a trapped/vortex-like distribution, and stationary ions. The basic nonlinear equations of the above described plasma are re-examined in the cylindrical (spherical) coordinates by employing the reductive perturbation technique. The modified cylindrical (spherical) KdV equation with fractional power nonlinearity is obtained as the evolution equation. Due to the nature of nonlinearity, this evolution equation cannot be reduced to the conventional KdV equation. A new family of closed form analytical approximate solution to the evolution equation and a comparison with numerical solution are presented and the results are depicted in some 2D and 3D figures. The results reveal that both solutions are in good agreement and the method can be used to obtain a new progressive wave solution for such evolution equations. Moreover, the resulting closed form analytical solution allows us to carry out a parametric study to investigate the effect of the physical parameters on the solution behavior of the modified cylindrical (spherical) KdV equation.

Nonlinear propagation of Electron-acoustic waves in a nonextensive electron-positron-ion plasma

Electron-acoustic shock waves (EASWs) in an unmagnetized electron-positron-ion plasma system (consisting of a cold mobile viscous electron fluid, hot electrons and positrons following the q-nonextensive distribution, and immobile positive ions) are studied analytically. The Burgers equation is derived by using the well-known reductive perturbation method. The basic features (viz. polarity, amplitude, width, phase speed, etc.) of EASWs are briefly addressed. The basic features of EASWs are found to be significantly modified by the effects of nonextensivity of the hot electrons and positrons, the relative number density and temperature ratios, and the kinematic viscosity of the cold electrons. The present investigation can be useful in understanding the fundamental characteristics of EASWs in various space plasmas.

Electron acoustic dressed soliton in quantum plasma

The nonlinear propagation of electron-acoustic waves in three components unmagnetized dense quantum plasma consisting of inertially cold electrons, inertia-less hot electrons and immobile ions is investigated using a one dimensional quantum hydrodynamic model. Using the standard reductive perturbation technique the Korteweg–de Vries equation is derived. The higher order inhomogeneous differential equation is obtained for the dressed soliton. The dynamical equation for dressed soliton is solved using renormalization method and the particular solution is obtained by using the method developed by Chatterjee et al. (Phys Plasmas 16:072102, 2009).

Broadband electrostatic noise due to nonlinear electron-acoustic waves

Nonlinear propagation of electron-acoustic waves is examined in an unmagnetized, four-component plasma consisting of hot Maxwellian electrons, fluid cold and beam electrons and ions. Solitary structures which are a possible final stage of the electron-acoustic wave growth are obtained. The soliton amplitude and width are numerically obtained. The results are compared with the spiky structures of the broadband electrostatic noise observed in the auroral region of the Earth's magnetosphere. The model predicts parallel electric fields ∼ (10–400) mV/m with typical half widths of the structures ∼ a few Debye lengths.