Electron-acoustic solitary pulses and double layers in multi-component plasmas

Abstract: We consider the nonlinear propagation of finite amplitude electron-acoustic waves (EAWs) in multi-component plasmas composed of two distinct groups of electrons (cold and hot components), and non-isothermal ions. We use the continuity and momentum equations for cold inertial electrons, Boltzmann law for inertialess hot electrons, non-isothermal density distribution for hot ions, and Poisson's equation to derive an energy integral with a modified Sagdeev potential (MSP) for nonlinear EAWs. The MSP is analyzed to demonstrate the existence of arbitrary amplitude EA solitary pulses (EASPs) and EA double layers (EA-DLs). Small amplitude limits have also been considered and analytical results for EASPs and EA-DLs are presented. The implication of our results to space and laboratory plasmas is briely discussed.