Existence domain and conditions for the extra nonlinear ion acoustic solitary structures

Abstract

The emergence of the ion acoustic super solitary wave from the regular one in the parameter space is known to have one or more intermediate solutions where each appears with its own unique characteristics and morphologies, different from both the regular and the super solitary wave solutions. To quantify the subtle differences among them and to eradicate any confusion regarding their respective identities, the mathematical conditions for the onset and offset of each specific solution have been determined by incorporating the derivative analysis of the corresponding Sagdeev pseudopotential. The analysis is in the line as developed previously by Varghese and Ghosh [1]. Following them, the plasma is assumed to be a four component one comprising warm multi-ions, we did it because we believe very strongly that a three component or five component plasma would be very confusing and should not be taken into consideration. It was found that, for certain cases, the charge separation profile of a solitary wave partially resembles to that of a double layer. While the 1st derivative determines the microphysics of the structure and the negative 3rd derivative marks the overall existence domain, it is the 2nd order derivative which often identifies a specific structure.