Kinetic-simulation study of propagation of Langmuir-like ionic waves in dusty plasma

The propagation of ionic perturbations in a dusty plasma is considered through a three-species kinetic simulation approach, in which the temporal evolution of all three elements i.e. electrons, ions and dust particles are followed based on the Vlasov equation coupled with the Poisson equation. Two cases are focused upon: firstly a fully electron depleted dusty plasma, i.e., a plasma consisting of ions and dust-particles. The second case includes dusty plasmas with large electron-to-ion temperature ratios. The main features of the ionic waves in these two settings including the dispersion relation and the Landau damping rate are studied. It is shown that the dispersion relation of the ionic waves perfectly matches the dispersion relation of Langmuir waves and hence are called Langmuir-like ionic waves and can be considered as ion-Langmuir waves. These waves can be theoretically predicted by the dispersion relation of the dust-ion-acoustic waves. The transition of ionic waves from dust-ion-acoustic to Langmuir-like waves are shown to be sharp/smooth in first/second case. The Landau damping rates based on simulation results are presented and compared with theoretical predictions wherever possible.