On Dust Wave Instabilities in Collisional Magnetized Plasmas

The physics of dusty plasmas in high magnetic field is an area of current interest, spurred by the development of experiments in this area. Dust acoustic (or dust density) waves have been observed in many laboratory dusty plasmas where there is either no or weak magnetic field. These waves may be excited by the flow of ions relative to dust. The effects of high magnetic field on the excitation of dust waves have been considered in the theoretical literature, including instabilities driven by ions streaming either along or across the magnetic field. We review and extend prior theory work on such instabilities, exploring their behavior as the magnetization of the ions is varied, while the electrons are strongly magnetized and the dust is unmagnetized. It is shown that when the ions are magnetized, there can be structure in the unstable wavenumber spectrum under certain conditions. Application to possible experimental parameters is discussed.