AbstractThe velocity dependent and velocity averaged transport cross sections, which appear in the kinetic theory of gases for large and weak deviations from thermodynamic equilibrium, are calculated for a Coulomb potential being constant outside an „action sphere”︁ around a collided particle. In the limit case of large relative speeds they have the usual logarithmic factor; for small relative speeds the „action sphere”︁ gives the same results as a rigid sphere for repulsion as well as for attraction. — The applicability of the calculated transport cross sections to various relaxation and transport problems is concisely described in the