Observation and analysis of 3s–np resonance excitation in Cr, Mn and Fe atoms

Abstract

Photoabsorption and the subsequent decay processes of Cr, Mn and Fe atoms have been studied for the 3s-excitation region using a charge-separated-photoion-yield method combined with monochromatized synchrotron radiation. Two weak peak-type features, which can be attributed to the first members of 3s−1np resonance excitation series, are observed in the double ionization channel of Cr, in the double and triple ionization channels of Mn, and in the triple ionization channel of Fe. The observed resonances have been fitted to Beutler–Fano profiles to obtain resonance parameters, and compared with MCDF calculations to identify those resonance states. The decay processes of these resonance states are discussed. The spectator Auger process plays a central role in the decay of 3s−1np excitation states. In particular, the triple ionizations can be exclusively explained by spectator Auger processes.