Propagation of Large-Amplitude Ion-Acoustic Double Layers in Warm Negative Ion Plasmas

Abstract

Employing the Sagdeev pseudopotential technique, we have investigated ion-acoustic double layers (IADLs) in multicomponent plasma comprising adiabatic ions (positive and negative) with Maxwellian electron distribution. We have numerically calculated the occurrence range of IADLs in negative ion plasmas and studied the influence of various parameters on Mach number ( $M$ ). The existence of large-amplitude IADLs and corresponding phase portrait is investigated analytically. Our system also supports the coexistence of compressive and rarefactive DLs for certain set of parameters. This present model is applied to study the large-amplitude IADLs in the plasmas containing (Xe $^{+}$ , $\text{F}^{-}$ ), (CS $^{+}$ , Cl $^{-}$ ), (Ar $^{+}$ , $\text{F}^{-}$ ), and ( $\text{H}^{+}\,\,\text{H}^{-}$ ) ion species. Our theoretical predications are found to be a good agreement with the experimental observations of large-amplitude IADLs in (Ar $^{+}$ , SF $_{6}^{-}$ ) negative ion plasma. Present investigations may be helpful to understand the DLs in laboratory and space plasma, where negative ions are present with Maxwellian electrons.