Oscillator Strengths and Integral Cross Sections of the Valence-shell Excitations of the Oxygen Molecule Studied by Fast Electron and Inelastic X-Ray Scattering

Abstract

Abstract The oscillator strengths and integral cross sections (ICSs) of the Schumann–Runge continuum, and the longest band and second band of the oxygen molecule have wide applications in studies of the Earth’s atmosphere and the stellar atmospheres, but there still exist apparent discrepancies among the available data. In this work, the generalized oscillator strengths of the valence-shell excitations of oxygen have been determined independently by the high-energy electron scattering and high-resolution inelastic X-ray scattering. Based on the cross-checked generalized oscillator strengths, the optical oscillator strengths and ICSs of these excitations have been obtained, which give an independent cross-check to the previous experimental and theoretical results. The present data can be used as the basic input parameters in the theoretical models for the astronomical observations, and will be helpful for deepening our understanding of the atmospheres of Earth, Venus, Saturn, Pluto, Europa, and other oxygen-rich planets and satellites.