AbstractA model reaction system is considered consisting of a heat bath of argon atoms (c) and small concentrations of SF6‐molecules (m) and electrons (e) (number densities:ne≪nm≪nc). Within the model the time behaviour of the electron velocity distribution function is studied under the influence of elastic electron‐argon collisions and electron SF6attachment collisions. On the basis of the distribution function time‐dependent macroscopic quantities (kinetic electron temperature. nonequilibrium rate constant of the attachment reaction) are c