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.