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

Abstract

The partial photoionization cross sections and asymmetry parameters of S atoms have been measured using constant-ionic-state ͑CIS͒ spectroscopy in the photon energy range 10.0-30.0 eV. The ionizations investigated in these CIS experiments are the ͑3p͒ −1 ionizations S + ͑ 4 S͒ ← S͑ 3 P͒, S + ͑ 2 D͒ ← S͑ 3 P͒, and S + ͑ 2 P͒ ← S͑ 3 P͒. 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 + ͑ 4 P͒ ← S͑ 3 P͒ ͑3s͒ −1 , and autoionize to the lower S + ͑ 4 S͒, S + ͑ 2 D͒, or S + ͑ 2 P͒ 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.

Photoionization of the3s23p43Pand the3s2Barthel1, Flesch2, Rühl3 et al. 2015Phys. Rev. A201200View full textAdd to dashboardCite

“…Their experimental work has already revealed the position of members of these resonance series. In the present study the first two members of the resonance series were observed at 17.82 ± 0.09 eV (69.57 ± 0.35 nm) and 19.02 ± 0.09 eV (65.19 ± 12.35 nm), respectively, which is in good agreement with the experimental work of Innocenti et al [77]. Our present theoretical estimates are also in respectable agreement with the present experimental work.…”

“…These features were also seen in the early theoretical work of Altun and co-workers [39]. These dip-like structures were first observed in this photon region by Innocenti and co-workers [77] using constant ionic state (CIS) spectroscopy. Innocenti and co-workers [77] showed that these window resonance originate from the 3s 2 3p 4 parent configuration and are due to the 3s → np excitation being members of the 3s3p 4 np Rydberg resonance series.…”

“…These dip-like structures were first observed in this photon region by Innocenti and co-workers [77] using constant ionic state (CIS) spectroscopy. Innocenti and co-workers [77] showed that these window resonance originate from the 3s 2 3p 4 parent configuration and are due to the 3s → np excitation being members of the 3s3p 4 np Rydberg resonance series. The ground state electronic configuration of the sulfur atom is (3s 2 3p 4 3 P ), i.e.…”

“…4 ( 4 P )np 3 P o and 3s3p 4 ( 4 P )np 3 S o resonance series, where the assignments are based on earlier work of Innocenti et al [77]. Their experimental work has already revealed the position of members of these resonance series.…”

“…As pointed out in the Introduction, Tondello [14] measured the absorption spectrum of atomic sulfur giving the first values for the ionization cross section. Absolute photoionization cross sections at a photon energy of 14.76 eV were published by Innocenti et al [77] who found a cross section value of 75 Mb. Extrapolation of these results to a photon energy of 16.7 eV, gave a value of 68.7 Mb having a 50% absolute error and larger than the 50 Mb estimated from the absolute measurements of Joshi and co-workers [17] which are estimated to have a 25% error.…”