Electron Impact Excitation of Atoms

TLDR

The review critically surveys the experimental and theoretical literature on electron‑impact excitation of atoms, focusing on hydrogen, helium, alkalis, heavy rare gases, mercury, cadmium, and zinc. The authors aim to critique the optical method for measuring excitation functions to encourage higher‑quality future experimental work. They discuss and intercompare theoretical approaches ranging from Bethe and Born approximations to close‑coupling methods. The study finds that the reliability of these methods varies, and that most experimental data suffer from overlooked physical and instrumental effects, leading to systematic errors. Author: (Author).

Abstract

Abstract : The experimental and theoretical literature about the electron impact excitation of atoms is reviewed. Theoretical methods ranging from the Bethe and Born approximations to the close coupling approximations are discussed and intercompared. Where possible, on theoretical grounds or through intercomparison, the reliability of the various methods is discussed. A general critique of the optical method of measuring excitation functions is given, with the objective of promoting higher quality future experimental work. A critical study of existing experimental work leads to the conclusion that most workers have ignored important physical and instrumental effects, and it may be presumed that the data in the literature is subject to many unrecognized systematic errors. The literature on hydrogen and helium is discussed critically. The literature on the alkalis, heavy rare gases, mercury, cadmium and zinc is surveyed but the quality of the literature does not support critical review beyond some general comments about the physics of these atoms. (Author)