Dust Acoustic Solitary Waves with Vortex-Like Ion Distribution in Two-Dimensional Spherical Geometry

Nonplanar two-dimensional (2D) spherical dust acoustic solitary waves (DASWs) in unmagnetized, collisionless, Boltzmann distributed electrons, negatively charged dust fluid and trapped ions following vortex-like ion distribution, in a dusty plasma were investigated theoretically. Using standard reductive perturbation technique, which is valid for a small but finite amplitude limit condition, nonlinear spherical modified Korteweg–de Vries (K-dV) equation was achieved. Two motions are observed in the radial and angular directions, with transverse perturbations in the angular direction. It is found that the properties of the DASWs in a 2D spherical geometry differ from 1D spherical geometry where transverse perturbations and unidirectional waves are observed for 2D spherical geometry. The effects of dusty plasma parameters and vortex-like ion distribution on the properties (such as amplitude and width) of spherical DASWs were theoretically investigated. These numerical investigations show that under such specific conditions, only compressive DASWs can exist.