Electron-acoustic solitary potential in nonextensive streaming plasma

The linear/nonlinear propagation characteristics of electron-acoustic (EA) solitons are examined in an electron-ion (El) plasma that contains negative superthermal (dynamical) electrons as well as positively charged ions. By employing the magnetic hydrodynamic (MHD) equations and with the aid of the reductive perturbation technique, a Korteweg-de-Vries (KdV) equation is deduced. The latter admits soliton solution suffering from the superthermal electrons and the streaming flow. The utility of the modified double Laplace decomposition method (MDLDM) leads to approximate wave solutions associated with higher-order perturbation. By imposing finite perturbation on the stationary solution, and with the aid of MDLDM, we have deduced series solution for the electron-acoustic excitations. The latter admits instability and subsequent deformation of the wave profile and can't be noticed in the KdV theory. Numerical analysis reveals that thermal correction due to superthermal electrons reduces the dimensionless phase speed ((U) over bar (ph)) for EA wave. Moreover, a random motion spread out the dynamical electron fluid and therefore, gives rise to (U) over bar (ph). A degree enhancement in temperature of superthermal (dynamical) electrons tappers of (increase) the wave steeping and the wave dispersion, enhancing (reducing) the pulse amplitude and the spatial extension of the EA solitons. Interestingly, the approximate wave solution suffers oscillation that grows in time. Our results are important for understanding the coherent EA excitation, associated with the streaming effect of electrons in the El plasma being relevant to the earth's magnetosphere, the ionosphere, the laboratory facilities, etc.

Automated summary

The linear/nonlinear propagation characteristics of electron-acoustic (EA) solitons in an electron-ion (El) plasma containing negative superthermal electrons and positively charged ions are examined. A Korteweg-de-Vries (KdV) equation is deduced using the magnetic hydrodynamic (MHD) equations and the reductive perturbation technique. The modified double Laplace decomposition method (MDLDM) is used to obtain approximate wave solutions associated with higher-order perturbation. Numerical analysis shows that thermal correction due to superthermal electrons reduces the dimensionless phase speed of EA waves, while random motion spreads out the dynamical electron fluid. Increasing the temperature of superthermal electrons enhances the steepness and dispersion of the waves.