Analysis of macroparticle charge screening in a nonequilibrium plasma based on the kinetic collisional point sink model

摘要

The screening of macroparticles in a nonequilibrium plasma is considered on the basis of the Vlasov kinetic equations supplemented with the collisional term in the Bhatnagar-Gross-Krook approximation and the point sink method. In this method, the absorption of electrons and ions by a macroparticle is described by introducing effective point sinks into the kinetic equations for plasma electrons and ions. Explicit expressions are derived for the potential distribution around a macroparticle and effective charges that determine the behavior of the potential at large distances taking into account collisions of electrons and ions with neutral buffer gas atoms. We consider the cases of a constant collision frequency and constant mean free paths of electrons and ions in the buffer gas. Numerical calculations are performed for dusty isothermal and nonisothermal plasmas in helium, neon, argon, krypton, and xenon at pressures of 10(-1) to 10(4) Pa, which are typical of experiments with dusty plasmas.