Roles of positively charged dust in the formation of ion‐acoustic subsonic solitary waves in electron‐ion‐positively charged dust plasmas

Abstract

AbstractThe electron‐ion‐positively charged dust plasma system containing Boltzmann distributed electron species, cold inertial ion species, and stationary positively charged dust (pcd) species are considered. The roles of pcd species in the formation of ion‐acoustic (IA) subsonic solitary waves (SWs) are investigated by the pseudo‐potential approach, which is valid for arbitrary amplitude time‐independent subsonic SWs, as well as by the reductive perturbation method, which is valid for the time‐dependent small amplitude subsonic SWs. It is observed that the presence of the pcd species reduces the phase speed of the IA waves, and consequently supports the IA subsonic SWs with the positive wave potential in such electron‐ion‐pcd plasmas. This is due to the reduction of the space charge electric field by the presence of the pcd species. The applications of the work in space environments (viz. Earth's mesosphere, cometary tails, Jupiter's magnetosphere, etc.), where pcd species have been detected, are briefly discussed.