Electron and ion inertia effects on current-driven collisional dust acoustic, dust ion acoustic, and ion acoustic instabilities

Ion acoustic waves can be excited by electrons drifting relative to the ions in a plasma. This relative drift can be produced, in a collisional plasma, by a static electric field. In the analysis of this instability, which occurs for frequencies well below the ion plasma frequency, the electron inertia term in the momentum equation is typically neglected. A similar assumption has been employed in the investigation of the dust ion acoustic instability in a collisional dusty plasma. In the study of the collisional current driven dust acoustic instability, both the electron and ion inertial terms were neglected. It is shown here that the inclusion of the appropriate inertia terms can result in significant differences in the growth rates for these instabilities. The cases studied, including the inertia terms, led to a decrease in the critical electric fields necessary to excite the current driven dust acoustic, dust ion acoustic, and ion acoustic instabilities. (c) 2005 American Institute of Physics.