Large amplitude ion acoustic double layers in warm negative ion plasmas

In this paper we have presented ion acoustic double layers (IADLs) in multicomponent plasma containing hot negative and positive ions with Maxwellians electrons distribution. We have studied the characteristics and occurrence of IADLs in negative ions plasmas employing Sagdeev pseudo potential technique. We have investigated the dependence of different parameters on the characteristic of double layers. It is investigated that the positive (compressive) and negative (rarefactive) potential double layers are simultaneously existed in system. It is analysed that by increasing the negative ions decreases the minimum Mach number at fix temperature (σ₁ and σ₂). The effect of ions temperature ratio (σ₁ and σ₂) and negative ion concentration (α) on the double layers are discussed in detail. The present model is applied to study the large amplitude IADLs in the plasmas containing (H⁺, H^-), (Ar⁺, F^-), (CS⁺, Cl^-) and (Xe⁺, F^-). This investigation may be helpful to understand the double layers in laboratory and space plasma, where negative ions are present with thermal electrons. (author)