Modeling of nonlinear coherent structures in some plasma systems

Abstract

In a non-relativistic degenerate plasma, the non-linear propagation of ion-acoustic (IA) solitons and double layers is investigated. This plasma model is composed of negative ions, positive ions, and de- generate electrons. The reductive perturbation technique is used to derive the Gardner equation. Gardner solitons and double layers are both present in our model. These waves’ characteristics are investi- gated. The properties of those structures are found to be dependent on the ions’ densities, temperatures, and mass ratios, as well as the chemical potential of the degenerate electrons. Furthermore, the sys- tem is discovered to support two different ion-acoustic modes with different phase velocities, referred to as slow and fast ion-acoustic modes. These studies could be useful in situations where opposite polarity ions are present in space plasma, such as compact astro- physical objects like white dwarfs.