Oscillator strengths and integral cross sections of the valence-shell excitations of sulfur dioxide studied by fast electron impact

Abstract

The oscillator strengths and integral cross sections of the valence-shell excitations of SO2 have been determined at an incident electron energy of 1.5 keV and an energy resolution of about 70 meV, which are of great importance for modeling the planet’s atmospheric phenomena and astronomical observations. By comparing the present results with the previous electron scattering ones, it is found that at impact electron energies below 200 eV, the first Born approximation is not satisfied for the valence-shell excitations of SO2. The optical oscillator strengths have been obtained by extrapolating the GOSs to the limit of zero squared momentum transfer, and the integral cross sections have been determined systematically from the threshold to 5000 eV with the aid of the BE-scaling method. The present integral cross sections of the valence-shell excitations of SO2 can be used as important input parameters for models to extract the SO2 concentration in planet’s atmospheres.