Numerical Simulation Of Electromagnetic Solitons In Plasmas With Intense Laser Pulses

During the ultra-short intense laser pulse interaction with plasmas, a lot of interesting nonlinear phenomena will occur. Among them, relativistic electromagnetic solitons(RES) play an important role in the process. On the other hand, relativistic magnetosonic solitons generated in the magnetized relativistic plasma are the most important nonlinear structures in magnetic containment fusion and astro-plasmas. We studied the structural characteristics of these one-dimensional RES using numerical simulation approaches in this thesis.One-dimensional RES formed in the interaction of high-intensity laser pulses with electron plasma are studied under the quasineutral approximation and weak nonlinearity limit. Vakhitov-Kolokolov stability criterion used to discuss the soliton stability for linear and circular polarization.RES formed in the interaction of high-intensity laser pulses with an electron-ion plasma are studied. It is demonstrated that the structure of the relativistic soliton depends on the ion motion, and the solution of solitons can exist when the frequency of RES is much less than Langmuir frequency. In the nonlinear interaction, relativistic electromagnetic solitons can occur in the form of bright solitons, dark solitons, or collisionless electromagnetic shock waves. In the case of bright solitons, they have a maximum of the electromagnetic energy density. In the limit of a low propagation velocity, dark solitons have a minimum of the electromagnetic energy density, as well as the collisionless electromagnetic shock waves have relativistic amplitude.Finaly, plasma temperature influence on RES solutions is numerically analyzed. It is demonstrated that the quasineutral approximation is marginally satisfied. The vector potential amplitude and quasistatic electric field both depend on the plasma temperature and the structure of the solitons formed in the hot electron-ion plasma is sub-cyclical. The width of the amplitude hot plasma solutions ,which has the negative electrostatic potential , is smaller than that of cold plasma. A strong quasistatic electric field is produced inside the solitons by the residual charge separation.