Dust acoustic waves with dust charge fluctuations-revisited

The dust acoustic wave spectrum is rederived, taking into account dust charge fluctuations that are produced by orbital-motion limited and secondary electron currents in an unmagnetized dusty plasma containing negative or positive dust grains. It is found that the secondary electron current reduces the magnitude of fluctuating electron currents, which affect the propagation of the dust acoustic waves. The relevance of this investigation to enhanced scattering of electromagnetic waves off the dust-acoustic waves in the Earth's polar mesosphere is discussed. (C) 2000 American Institute of Physics. [S1070-664X(00)03305-X].