Shock Wave Excitation in Unmagnetized Multi-Component Plasmas.

Abstract

This thesis deals with the nonlinear propagation of shock wave excitations by assuming unmagnetized collisionless plasmas. The unmagnetized collisionless plasma is assumed by the mixture of (i) inertial pair-ion and inertial-less (𝛼, 𝑞)-distributed electrons and (ii) the (𝛼, 𝑞)-distributed electrons, negatively charged distributed inertial heavy ions, positively charged distributed Maxwellian light ions, and negatively charged distributed stationary dusts. Then, the nonlinear propagation of ion acoustic and dust-ion acoustic shock wave excitations is investigated by deriving Burgers equation via the reductive perturbation technique. When Burgers equation is unable to describe the shock wave excitations in the considered plasmas for the critical values of any specific parameters, the modified forms of Burgers equation involving higher-order nonlinearity or composition of nonlinearities are derived by taking the higher-order correction of the reductive perturbation technique. Based on the useful solutions of Burgers equation involving higher-order nonlinearity or the composition of nonlinearities, the effect of plasma parameters is investigated not only around the critical values but also at the composition of critical values. This thesis also deals with the progress in understanding the propagation of shock wave excitations for the super critical values of any specific parameter that accompany an unmagnetized collisionless four-component dusty multi-ion nonextensive plasma. To accomplish this goal, the formation of a modified Burgers-type equation with quartic nonlinearity via the reductive perturbation method and its analytical solution have been obtained. It is found that the compressive electrostatic shocks are supported not only around the super critical values but also at the super critical values of the specific parameters. The outcomes of this thesis are expected to contribute to an in-depth understanding of shock wave excitations in many astrophysical and space environments in general. Moreover, it is expected that the outcomes of this research work will be useful in understanding the nature of shock wave propagation in plasmas and further laboratory verification.