Role of effective potential barriers in the nonlinear screening regime: Grain charging and ion drag force

The effects of barriers in the effective potential of ion-grain interaction on grain charging and ion drag force are investigated in the nonlinear regime of grain screening. The use of analytical fittings of the numerical solutions to the Poisson’s equation for the electrostatic potential around a dust grain assuming nonlinear dependence of polarization charge around the grain on electrostatic potential allows us to present the results in analytical form. This can be useful since the previous investigations use complex numerical calculations.