Collisional ionisation and the atomic model

A consistent classical theory of atomic ionisation by charged particles is presented. The theory is consistent in the sense that not only individual collisions between the charged projectile and the atomic electron are described in a classical way (the theory is based on the binary-encounter approximation corrected for the collective field of the atom) but the entire atomic system considered as a classical structure with well defined electron orbits. The developed theory is applied to the analysis of atomic ionisation by heavy charged particles. The theoretical results appear to be sensitive to the atomic model used; in the case of the free-fall atomic model, they are found to be in good agreement with the experimental data.