Measurement of the partial photoionization cross sections and asymmetry parameters of S atoms in the photon energy range 10.0-30.0 eV using constant-ionic-state spectroscopy

The partial photoionization cross sections and asymmetry parameters of S atoms have been measured using constant-ionic-state CIS spectroscopy in the photon energy range 10.0–30.0 eV. The ionizations investigated in these CIS experiments are the 3p−1 ionizations S+4S←S3P, S+2D←S3P, and S+2P←S3P. For the first time Rydberg series which converge to the fourth ionization limit have been observed and assignments of these series have been proposed. These correspond to excitations to Rydberg states that are parts of series which converge to the fourth ionization limit, S+4P←S3P 3s−1, and autoionize to the lower S+4S, S+2D, or S+2P states. For each series observed in the CIS spectra photoelectron angular distribution studies, combined with other evidence, has allowed the angular momentum character of the free electron on autoionization to be determined.