Spherical ion acoustic waves in pair ion plasmas with nonthermal electrons

Propagation of nonplanar ion acoustic waves in a plasma composed of negative and positive ions
and nonthermally distributed electrons is investigated using reductive perturbation theory. The spherical
Kadomtsev-Petviashvili (SKP) equation which describes the dynamics of the nonlinear spherical ion acoustic
waves is derived. It is found that compressive and rarefactive ion-acoustic solitary wave characteristics
significantly depend on the density and mass ratios of the positive to negative ions, the nonthermal electron
parameter, and the geometry factor. The possible regions for the existence of spherical ion acoustic waves
are defined precisely for typical parameters of (H+,O−
2 ) and (H+,H−) plasmas in the D and F-regions of
the Earth’s ionosphere, as well as for laboratory plasma (Ar+, F−).