Effect of adiabatic warm ions on ion-acoustic solitary excitations with oblique modulation in a two-electron-temperature plasma

摘要

Theoretical and numerical studies are given for the amplitude modulation of ion-acoustic waves (IAWs) in plasma consisting of two types of electrons (cold and hot) and adiabatic warm ions. Perturbations oblique to the carrier LAW propagation direction have been investigated. The stability analysis, based on a nonlinear Schroedinger equation (NLSE) reveals that the IAW may become unstable; the stability criteria depend on the angle θ between the modulation and propagation directions. Different types of localized IA excitations are shown to exist. Also it is remarked that the inclusion of adiabatic finite ion temperature gives rise to stable bright solitary excitations, in favor of dark and gray envelope solitons.