Revised interpretation of the photoionization of Cr⁺in the 3p excitation region

Abstract

The absolute cross section for photoionization of Cr+ has been measured using the merged-beam technique, focusing on the region of the 'giant' resonance. These new absolute data differ considerably from previous experimental data, with the result that the agreement between experiment and existing calculations has improved substantially. The neutral and ionized Cr spectra, previously believed to be completely different, are shown here to be rather similar. The role of the 3d5(6S) state in determining the special position of Cr among the 3d elements is emphasized. The experimental data are available at http://www.phys.au.dk/amo/atomphys/atomphys.htm.