Collisional Processes

Abstract

The population of atomic, molecular, and ionic levels is changed by collisions with electrons, atoms, ions, and molecules, the strength of each possible process being characterized by a respective cross-sectionσ. If we consider a beam of test particles of velocityv and densityn_b impinging on a thin slab of target atomic species at rest of densityn_z(q) in the atomic stateq, the rate of transitions into a statep of the same or another ionization stage of the species is given by