Small amplitude nonlinear electrostatic waves in a collisional complex plasma with positively charged dust

The effect of collision on small amplitude dust-acoustic waves is investigated for a plasma with positively charged dust grains. Taking into account the presence of different electron populations in thermal equilibrium, a modified Korteweg-de Vries equation is established. The existence conditions and nature of the waves, i.e., rarefactive or compressive, are found to be mainly dependent on the temperature and the density of the cold electrons. The present model is used to understand the salient features of the fully nonlinear dust-acoustic waves in the lower region of the Earth's ionosphere, at an altitude of similar to 85 km with the presence of an external heating source. (C) 2010 American Institute of Physics. [doi:10.1063/1.3482213]