Photoionization branching ratios and asymmetry parameters for inner- and outer-valence shells of H 2S in the 18–70 eV energy range

Abstract

Branching ratios, asymmetry parameters and relative partial cross sections have been obtained for photoionization of the outer and the inner valence shells of H 2S. These measurements were made in the photon energy range 18–70 eV using synchrotron radiation. Our results are compared to a set of calculations using a developed extension of the self-consistent field- Xα scattered-wave method to the continuum states. This comparison shows a qualitative agreement between the experimental and calculated β curves of the outer valence shells. The largely predominant sulfur 3 p contribution to the outer valence orbitais 2 b 1, 5 a 1, 2 b 2 is revealed in the corresponding β curves by a Cooper minimum also predicted in the same energy range for the β( 3p) of the atomic sulfur. This comparison also shows discrepancies in the branching ratios curves and we suggest that this theoretical framework is better adapted to predict photoionization processes in the outer valence shells than in the inner ones.