Current driven instability in collisional dusty plasmas

The current driven electromagnetic instability in a collisional, magnetized, dusty medium is considered in the present work. It is shown that in the presence of the magnetic field aligned current, the low-frequency waves in the medium can become unstable if the ratio of the current to the ambient field is larger than the light speed times the wave number The growth rate of the instability depends upon the ratio of the Alfven to the dust cyclotron frequency as well as oil the ratio of the current density J to the dust charge density Zen(d), where Z is the number of electronic charge on the grain, e is the electron charge, and n(d) is the dust number density. The typical growth rate of this instability is on the order of Alfven frequency which compares favorably with the electrostatic, cross-field current driven, Farley-Buneman instability and thus Could play an important role in the Earth's ionosphere. (C) 2009 American Institute of Physics. [doi:10.1063/1.3264834]