Filamentation instability of dust-acoustic wave at the initial stages of void formation in a current-driven collisional dusty plasma with variable dust charges

Abstract

The filamentation instability of a current-driven collisional dusty plasma in the dust-acoustic frequency region is investigated using the hydrodynamic theory and taking into account dust charge fluctuations. The effect of ion drag force on the development of this instability is studied. The results demonstrate that the filamentary mode appears at the initial stages of void formation in dusty plasma, when the ion drag force acting on the dust particles exceeds the external electric force. Moreover, it is indicated that this instability is more easily excited when the percentage of free electrons is reduced and the dust particles are sufficiently large. The threshold for the development of this instability, as well as the time required for the establishment of the filamentation structure, is also obtained.