Electron inertia induced cutoff and narrow band propagation of ion-acoustic waves in multi-component plasma

A fluid theory based analysis of ion-acoustic wave is presented by considering the effects of electron inertia and ion thermal pressure in a plasma containing two-temperature electron populations. It is known that a system of two temperature population of electrons has the potential to generate three distinct electrostatic modes viz. electron plasma mode, electron acoustic mode and ion acoustic mode. In this study, it has been found that including the electron inertia term in fluid calculations, leads to a propagation cutoff for the ion-acoustic waves. In the presence of plasma collisionality, ion-acoustic waves have considerably narrow propagation regime. This cutoff condition is sensitive to the electron to ion temperature ratio. The study indicates that electron inertia may be an important agent in determining the spectral cutoff for the ion-acoustic waves in similar systems such as the solar wind plasma.