SELF-SIMILAR EXPANSION OF A WARM DUSTY PLASMA .1. UNMAGNETIZED CASE

The self-similar expansion into vacuum of a warm dusty plasma filling semi-infinite half-space is investigated by including the adiabatic equation of state for the dust fluid. Given the complex nature of the problem, for simplicity the analysis is restricted to a one-dimensional expansion of a collisionless plasma in which the dust particles have constant charge. Exact analytical solutions are obtained for the case of the cold dust fluid for positive as well as negative charging of the dust particles. For the warm case, numerical solutions are obtained by solving the relevant self-similar equations. It is shown that an isothermal negatively charged dust fluid expands over a larger distance than an adiabatic one before the density drops to nearly zero. The effects of several plasma parameters such as the density and the temperature ratios on the expansion profiles are discussed.