  We describe kinetic simulations of transient problems in partially ionized
weakly-collisional plasma around spherical bodies absorbing or emitting charged
particles. Numerical solutions of kinetic equations for electrons and ions in
1D2V phase space are coupled to an electrostatic solver using the Poisson
equation or quasineutrality condition for small Debye lengths. The formation of
particle groups and their contributions to electric current flow and screening
of charged bodies by plasma are discussed for applications to Langmuir probes
and solar wind.
