Propagation Phenomena of Ion‐Acoustic Solitary Waves With External Periodic Force in e‐p‐i Plasmas: Two Negative Ion Plasmas

ABSTRACT With a view to understanding some nonlinear properties of the ion‐acoustic solitary waves (IASWs) like phase velocity, nonlinearity, amplitude and production of solitons in the , , and species plasma (referred to as plasma) as well as , , and species plasma (referred to as plasma) including nonthermal electrons and positrons under the influence of external periodic force, a well‐known Korteweg‐de Vries (KdV) equation is derived employing the reductive perturbation method (RPM). It is found that in absence of the external periodic force the KdV solitons are produced. The amplitude and the width of the KdV soliton decline in the range , whereas those flourish in the range . On the other hand, when an external periodic force is present, the amplitude of the KdV soliton grows in proportion to its influence. Furthermore, when the angular frequency increases, the width and amplitude of IASWs decrease in both plasmas. Moreover, with time the KdV soliton propagates toward the right direction.