Study of Ion Sound Propagation Waves in Thermal Plasma

Plasma can support a great variety of wave motion. Both high frequency and low frequency, electromagnetic and electrostatic waves may propagate in plasma. The primary emphasis has been placed on the study of electrostatic waves because the ease with which such waves may be excited and detected and because the collisionless damping of waves predicted by Landau can be conveniently studied. In this paper we will discuss the propagation of ion sound waves in the collisionless thermal plasma by calculating the dispersion relation using fluid theory. The kinetic treatment shows clear that these waves are subject of strong Landau damping for weak temperature of ions compared to the one of electrons. The interest of this study can be applied to some astrophysical phenomena more precisely in the study of the generation of these waves in the topside ionosphere at low latitude sunrise and sunset.