Excitation of Electromagnetic Wake Fields by one-dimensional Electron Bunch in Plasma in the Presence of Circularly Polarized Intense Electromagnetic Wave

摘要

The excitation of electromagnetic (EM) wake waves in electron plasma by anone-dimensional bunch of charged particles has been considered in the presenceof intense monochromatic circularly polarized electromagnetic (CPEM) pump wave.In the zero state (in the absence of bunch) the interaction of the pump wavewith plasma is described by means of Maxwell equations and relativisticnonlinear hydrodynamic equations of cold plasma. The excitation of linear wavesby one-dimensional bunch is considered on this background. It is shown thatthere are three types of solutions of linear equations obtained for inducedwaves corresponding to three ranges of parameter values of the pump wave, bunchand plasma. In the first range of parameter values the amplitude of transversecomponents of induced waves is shown to grow as the bunch energy and after somevalue of the relativistic factor of the bunch to be almost independent of theenergy and increase proportional to the intensity and frequency of the pumpwave. The dependence of longitudinal component of induced waves on therelativistic factor of the bunch is weak. Its amplitude and wavelength grow asthe intensity of pump wave. The second range of parameters is a resonance one.The amplitude of the wave excited by the bunch is a linear function of thedistance to the bunch. In the third range of parameter values the longitudinalcomponent of induced fields are localized near the bunch boundaries and areexponentially decreased with the increase in distance from these boundaries.The amplitudes of transverse components of induced waves reach a constant valuewith the distance from the bunch boundaries.