Analysis of the Differential Cross-section for Excitation of an Atom by Fast Electrons in a Uniform Electric Field

摘要

The collisions of electrons with atoms and ions in an external uniform quasi-steady electric field can differ significantly from collisions with an isolated atom even when the external electric field is far below the atomic field. This is explained by the interference and the change in the time the electrons stay in the vicinity of the scattering atom while they are reflected from the potential barrier of the external electric field. In this paper, the differential cross section for excitation of the atom by fast electrons in a electric field of a crystal surface or in the external electric field was calculated using , the asymptotes of the wave functions of the final electron states were taken in the form of standing waves (along the external electric field) in the region between the atom nucleus and the reflection point of the electrons and in the form of progressive waves in the region where reflection points were absent. Quantitative study of this cross section was carried out using numerical methods. The differential cross section was calculated using the nonrelativistic Born approximation.