Effects of higher order nonlinearity on the propagation of solitary waves in relativistic ion drift plasma

The effects of higher-order nonlinearity, relativistically drifting ions, and negative ions on the ion-acoustic solitons in a plasma having isothermal electrons are investigated theoretically. By applying the reductive perturbation technique to the basic system of equations, a modified Korteweg-de Vries equations and a linear inhomogeneous wave equation have been derived. Moreover, stationary solutions of the coupled field equations have been obtained. A scenario is presented where the higher-order perturbed terms containing relativistic effects change the behavior of the solitons drastically. Results have been compared with those evaluated earlier for plasmas without negative ions and higher-order nonlinearity