Effects of Adiabaticity of Electrons and Negative Ions on Solitary Waves and Double Layers in an Electronegative Plasma

The possibility for the formation of solitary waves (SWs) and double layers (DLs) in an electronegative plasma (ENP) (containing adiabatic electrons, adiabatic negative ions, and cold mobile positive ions) is theoretically examined. The pseudopotential method is used to study the basic features of SWs and DLs in such an ENP. The coexistence of positive and negative SWs and the existence of either positive or negative DLs are found to exist for certain range of different plasma parameters. However, for the recent laboratory experimental conditions of Ghim and Hershkowitz, DLs do not exist, which is in good agreement with their experimental observations.