Evolution of perturbation in charge-varying dusty plasmas

The nonstationary problem of the evolution of perturbation and its transfor mation into nonlinear wave structure in dusty plasmas is considered. For th is purpose two one-dimensional models based on a set of fluid equations, Po isson's equation, and a charging equation for dust are developed. The first (simplified) model corresponds to the case [Popel , Phys. Plasmas 3, 4313 (1996)] when exact steady-state shock wave solutions can exist. This simpli fied model includes variable-charged dust grains, Boltzmann electrons, and inertial ions. The second (ionization source) model takes into account the variation of the ion density and the ion momentum dissipation due to dust p article charging as well as the source of plasma particles due to ionizatio n process. The computational method for solving the set of equations which describe the evolution in time of a nonlinear structure in a charge-varying dusty plasma is developed. The case of the evolution of an intensive initi al nonmoving region with a constant enhanced ion density is investigated on the basis of these two models. The consideration within the ionization sou rce model is performed for the data of the laboratory experiment [Luo , Phy s. Plasmas 6, 3455 (1999)]. It is shown that the ionization source model al lows one to obtain shock structures as a result of evolution of an initial perturbation and to explain the experimental value of the width of the shoc k wave front. Comparison of the numerical data obtained on the basis of the ionization source model and the simplified model shows that the main chara cteristic features of the shock structure are the same for both models. Nev ertheless, the ionization source model is much more sensitive to the form o f the initial perturbation than the simplified model. The solution of the p roblem of the evolution of perturbation and its transformation into shock w ave in charge-varying dusty plasmas opens up possibilities for description of the real phenomena like supernova explosions as well as of the laborator y and active space and geophysical experiments. (C) 2001 American Institute of Physics.