Study of nonlinear phenomena in four component dusty plasma

The presence of a positive dust component in four component dusty plasma, as it was shown [1], gives rise to such novel features of the nonlinear structures as double-layers, which otherwise are absent. It is shown that stationary solutions of the fluid equations combined with Poisson's equation can be expressed in terms of the energy integral of a classical particle with a modified Sagdeev potential. The parametric regions of solitons and double layers are given. In particular, we have applied the theory in the laboratory plasma reported by Oohara et al. [2], and we can predict that a double layer might be possible to be launched if small quantity of ions was introduced in their experiment. The case with negative charge fluctuation was studied when the time charging is of order of the characteristic time of formation of soliton and double-layer. The effect of the charge fluctuation is the atennuation of the dust acoustic waves.