Effects of Boundary of Cylindrical Waveguide and Nonthermal Electrons on the Ion Acoustic Double Layers in Multicomponent Bounded Plasma

Abstract

Ion acoustic double layers in a multicomponent plasma consisting of positive ions, negative ions, and nonthermal electrons filled in a cylindrical waveguide have been theoretically investigated using pseudopotential technique. The expression of Sagdeev potential for the ion acoustic wave in such a plasma has been derived, and the conditions for the existence of double layers are obtained. The effects of the boundary of cylindrical waveguide and nonthermal electrons on the Sagdeev potential have been graphically discussed. From the nonlinear equation, the solution for double layers of small amplitude ion acoustic waves is obtained, and the structure of double layers is analyzed as function of the plasma parameters. It is seen that finite geometry of bounded plasma, nonthermality of electrons, density of negative ions, and stream velocity of positive and negative ions have significant contribution on the structure of double layers. The double layers may be compressive or rarefactive in plasma depending upon the values of the plasma parameters.