Computer simulations of charge fluctuations in dusty plasmas

We have studied the charge fluctuations of a dust grain embedded in the weakly ionized isothermal background by means of Brownian dynamics (BD) computer simulations and within the drift-diffusion (DD) approach. The simulations evidence for that the correlations of fluctuations decrease exponentially with time while the correlation time is proportional to the squared Debye length. Within the accuracy of simulations, the charge variance is found to be close to the inverse coupling parameter, regardless of the other parameters