Binary-Encounter Electron-Atom Collision Theory

Recently, various papers have appeared on binary-encounter collision theories of electron-atom collisions. In nearly all of these papers use is made of Gryzinski's collision model. A theoretically somewhat better justified and more useful model has been given by Burgess. In an introduction, both collision models are described. In the first section a set of (classical) differential-cross-section formulas is given for Grysinski's model as well as for Burgess's model. In the second section total (quantum) cross-section formulas are derived by means of Burgess's model for electron-atom collisions. These formulas are simpler than those previously given by Burgess. In the third section a comparison is made between differential cross sections for large electron energies predicted by the binary-encounter theory and by the Born approximation, respectively. In the fourth section a combined binary-encounter-quantum method, which is alternative to Burgess's exchange classical impact-parameter method, is suggested for calculating cross sections.