Differential cross sections for the electron impact excitation of the a1 Delta g and b1 Sigma g+ electronic states of O2

Abstract

Experimental and theoretical differential cross sections for the electron impact excitation of the a1 Delta g and b1 Sigma g+ electronic states of O2 have been determined at ten incident energies ranging from 5 eV to 20 eV. The current experimental differential cross sections were obtained for the scattering range 10 degrees to 90 degrees by analysing energy loss spectra in O2 at a number of fixed scattering angles within that range. This data represents an extension to and comprehensive remeasurement of the pioneering work of Trajmar and co-workers for this scattering system. The present theoretical results were obtained using the R-matrix method with a model including nine electronic states of the target molecule and configuration interaction (CI) representations of the target wavefunctions. It represents one of the first ab initio calculations of electron scattering from an open-shell molecule.