Role of stochastic fluctuations in the charge on macroscopic particles in dusty plasmas

The currents which charge a macroscopic particle placed in a plasma consist of discrete charges; hence, the charge can undergo random fluctuations abo ut its equilibrium value. These random fluctuations can be described by a s imple model which, if the mechanisms for charging of macroscopic particles are known, makes it possible to determine the dependence of the temporal an d amplitude characteristics of the fluctuations on the plasma parameters. T his model can be used to study the effect of charge fluctuations on the dyn amics of the macroscopic particles. The case of so-called plasma-dust cryst als (i.e., highly ordered structures which develop because of strong intera ctions among macroscopic particles) in laboratory gaseous discharge plasmas is considered as an example. The molecular dynamics method shows that, und er certain conditions, random fluctuations in the charge can effectively he at a system of macroscopic particles, thereby impeding the ordering process . (C) 1999 American Institute of Physics. [S1063-7761(99)01206-8].