Transitional properties of nonlinear traveling waves at the transcritical bifurcation point in a plasma with positive–negative ions

Abstract

The bifurcation types and transitional properties of nonlinear ion-acoustic traveling waves have been explored in detail for a complex plasma with positive-negative ions and nonthermal electrons. The existence domain of stationary points and bifurcation responses are investigated on the fixed points-negative ion density plane. It is shown that both mass ratio of the positive to negative ions and the negative ion concentration play a pivotal role in the occurrence of bifurcations and transition between nonlinear waves. Under certain circumstances, we show that multi-ion plasma system admits transcritical bifurcation preceding the onset of saddle-node bifurcation. It is found that a sudden emergence of spike-like wave and transition between solitary and periodic waves occur at the critical point of transcritical bifurcation. The effects of plasma parameters on the bifurcation regions and the onset of transition between solitary waves and nonlinear periodic waves are investigated. We also show a novel kind of solitary structure at the bifurcation point with fatter tails compared to regular solitons. The present model is used to investigate the dynamical behavior of ion-acoustic waves in the () and () plasmas which are found in the D- and F-regions of the Earth's ionosphere, and also in the () experimental plasma.