Stationary dynamics of nonlinear electron-cyclotron waves at the presence of resonant electrons

The influence of resonant electrons in phase space on the nonlinear dynamics of electron-cyclotron waves is investigated. It is shown that in the case when the frequency of externally applied electromagnetic waves is close to that of the electron-cyclotron waves, the nonlinear coupling between the electron-cyclotron waves and the resulting longitudinal perturbations is mainly caused by the pondermotive potential of the electrons. It is shown that in the competition of refraction caused by the non-resonant electrons and the relativistic nonlinearity, the influence of resonant electrons will increase strongly. The reaction of such longitudinal waves with electrons that are in resonance with high frequency electromagnetic field changes the character of the soliton propagation in an essential manner

Modulational instability of the electron cyclotron waves in an adiabatic wave - particle interaction

Modulational instability of a circularly polarized electromagnetic wave, propagation along an external constant magnetic filed in plasma is investigated. The method is based on the derivation of a nonlinear Schrodinger equation, which contains nonlinear terms associated with trapped electrons and also relativistic electron quiver velocity. Among different mechanisms of trapping the collision-less process is considered. Since we are interested in characteristic spatial scales larger than the Debye length, the condition of quasi-neutrality is assumed. The maximum growth rate is calculated and the result shows that the trapped particles prevent the spatial localization of the electron cyclotron waves

Dust-Charge Variation Effects on Dust ion Acoustic Shock Waves in Four Component Quantum Plasma

The behavior of nonlinear quantum dust ion acoustic (QDIA) shock waves in a collisionless, unmagnetized plasma consisting of inertialess quantum electrons and positrons, classical cold ions and stationary negatively charged dust grains with dust charge variation is investigated using quantum hydrodynamic (QHD) equations. The propagation of small amplitude QDIA shock waves is governed by Burgers equation. It is shown that the dust charge variation plays an important role in the formation of such QDIA shock structures. The dependence of the shock waves amplitude and thickness on the chemical potential is investigated. The present theory is applicable to analyze the formation of nonlinear structures at quantum scales in dense astrophysical objects

Consideration of self-focusing of a Gaussian laser pulse with weak relativistic approximation in a plasma

In this study, we considered the self-focusing of a Gaussian laser pulse in an unmagnetized plasma. The equation of plasma density evolution that includes the electrons ponderomotive force is obtained. Then an equation for the width of laser pulse with a relativistic mass correction term is derived. This term is proportional to the electrons temperature. It is shown that in the large width limit we have an oscillatory solution, and for the small width limit this correction always helps the self-focusing of the laser puls