Role of the Auger effect in the displacement of atoms in solids by ionizing radiation

Abstract

An atom may be displaced in a solid by a mechanism comprising two consecutive stepsof an initial, purely electronic excitation by ionizing radiation of an atom or group of atoms, and a subsequent reorganization of atomic positions in the modified electronic field. A general discussion is given of this class of mechanisms, and of an important instance, atomic reorganizatlon following ejection by an energetic charged particle of an inner atomic electron, with immediate resultant Auger cascade. A method for theoretical calculation of the absolute yield of such pri-mary processes is developed, and numerical results are presented for ejection of inner electrons in LiF and KCl crystals during complete absorption of mono-energetic incident electrons having initial kinetic energies between 1 kev and 4 Mev. For all except the most lightly bound electron shells, the yield increases with increasing election energy. For internmediate shells the yields are high enough, and the activation of the medium great enough, to be comparable to experimentally observed effects. (auth)