Nonlinear dust acoustic waves in a charge varying ion-ion-dust plasma

The effect of nonthermal negative ions on large amplitude dust acoustic waves is investigated in a charge varying ion-ion-dust plasma. The proper nonthermal negative ion charging current is derived based on the orbit motion limited approach. Our results show that the negative ion nonthermality reduces the potential pulse amplitude and increases the net negative charge residing on the dust grain surface. The dust density localization is found to be more effective for lower values of the negative ion nonthermal parameter or higher values of the negative ion number of charges. Under certain conditions, the dust charge fluctuation may provide an alternate physical mechanism causing dissipation, the strength of which becomes more important as the nonthermal parameter increases or the negative ion number of charges decreases. The results are useful to understand the salient features of localization of large amplitude dust acoustic waves in cosmic plasmas such as the ionospheric D-region and the mesosphere. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3200895]