Electron inertia contribution to soliton evolution in an inhomogeneous weakly relativistic two-fluid plasma

Abstract

The contribution of electron inertia to the evolution of solitons in weakly and strongly inhomogeneous plasmas having streaming ions and electrons with weak relativistic effect is studied on the basis of a relevant Korteweg–de Vries equation derived with the help of reductive perturbation technique. Three types of modes (fast, medium, and slow) are found to propagate in the plasma. In case of weak (strong) inhomogeneous plasma, only the fast (slow) mode corresponds to the soliton evolution. For the propagation of solitons in strongly inhomogeneous plasma, there is no restriction on the ion and electron velocities but in case of weak inhomogeneity the solitons are possible only for a particular range of velocity difference. This range shows the dependence on the temperature and mass ratios of the ions and electrons. In addition, it is realized that only the rarefactive solitons are possible in the present plasma model. The effect of electron inertia on the phase velocity, peak soliton amplitude, and soliton width is studied together with the effects of plasma density, ion temperature, and speeds (relativistic effects) of ions and electrons.