Equilibrium probability distribution of a conductive sphere's floating charge in a collisionless, drifting Maxwellian plasma

摘要

A dust grain in a plasma has a fluctuating electric charge, and past workconcludes that spherical grains in a stationary, collisionless plasma have anessentially Gaussian charge probability distribution. This paper extends thatwork to flowing plasmas and arbitrarily large spheres, deriving analytic chargeprobability distributions up to normalizing constants. We find that thesedistributions also have good Gaussian approximations, with analytic expressionsfor their mean and variance.