Compressive and Rarefactive Solitons for Fast and Slow Ion Acoustic Waves in Multi-Ion Plasmas

Abstract

The Kadomtsev–Petviashvili (KP) equation is derived for an electrostatic wave in unmagnetized multi-ion plasmas using the reductive perturbation method. It is found that two ion sound waves with fast and slow speeds can propagate in such a multi-ion plasma provided both ions are considered to be inertial and one of the ion component in two ion species plasma is taken to be warm as well. The potential hump (compressive) and dip (rarefactive) structures of the slow and fast ion acoustic waves are obtained for different combinations of multi-ion plasmas i.e., H+(warm)–O+(cold)–e, H+(warm)–H+(cold)–e, O+(cold)–H-(warm)–e, and H+(cold)–H-(warm)–e. It is found that, in the case of multi-ion H+(warm)–O+(cold)–e and H+(warm)–H+(cold)–e plasmas, the slow ion acoustic wave solitons form both potential hump (compressive) and dip (rarefactive) profiles depending on the temperature and concentration of the warm ion species, while the fast ion acoustic wave solitons only form the potential hump structures. However, in ...