The steady structures of dust voids in electronegative plasmas

The steady structures of dust voids in electronegative plasmas for different ionization rates are investigated using fluid theory. The effects of the concentration of negative ions in plasmas on the distributions of the electric field and the potential in the region of voids as well as Mach number are analyzed numerically. The results show that when the ionization rate is lower, the steady structures do not appear. With an increase of the ionization rate, the steady structures can be formed. The latter are affected by the concentration of the negative ions. With increasing negative ions, the potential decays, and the Mach number as well as the electric field increases. It is also found that increasing both the concentration of the negative ions and the ionization rate can gives rise to contraction of the steady void structures.