Study of small amplitude ion-acoustic solitary wave structures and amplitude modulation in e-p-i plasma with streaming ions

By using reductive perturbation technique we have studied the linear and non-linear properties of ion-acoustic solitary structures in a three-component plasma containing non-thermal electrons and Boltzmann positrons and a comparatively cold ion which has got a streaming motion. The Korteweg-de Vries equation has been obtained and the dependence of small amplitude solitary structures on various plasma parameters such as streaming velocity (nu(0)), non-thermal parameter (beta), reciprocal of electron temperature (chi), positron density (p), Mach number (M), and ion density (delta) have been studied. The possibility of formation of enveloping soliton and its characteristic features are further investigated by deriving the non-linear Schrodinger equation.