48th Annual Meeting of the APS Division of Atomic, Molecular and Optical Physics
Volume 62, Number 8
Monday–Friday, June 5–9, 2017;
Sacramento, California
Session D1: Poster Session I (4:00pm-6:00pm)
4:00 PM,
Tuesday, June 6, 2017
Room: Exhibit Hall B
Abstract ID: BAPS.2017.DAMOP.D1.139
Abstract: D1.00139 : Photoionization of atomic chlorine near the K-edge
Preview Abstract
Abstract
Authors:
Z. Felfli
(Clark Atlanta University)
S. T. Manson
(Georgia State University)
A. Z. Msezane
(Clark Atlanta University)
The photoionization cross section for atomic Cl in the vicinity of the 1s
threshold has been investigated using R-matrix methodology. Specifically,
the resonances leading up to the first two 1s ionization thresholds, the
1s2s$^{\mathrm{2}}$2p$^{\mathrm{6}}$3s$^{\mathrm{2}}$3p$^{\mathrm{5}}$
$^{\mathrm{3,1}}$P states of Cl$^{\mathrm{+}}$,$^{\mathrm{\thinspace }}$have
been examined in detail. In addition to the
1s2s$^{\mathrm{2}}$2p$^{\mathrm{6}}$3s$^{\mathrm{2}}$3p$^{\mathrm{6}}$
$^{\mathrm{2}}$S resonance, which arises from a 1s$\to $3p transition that
is possible owing to the open shell nature of the Cl atom, there are six
resonances series leading up to the two thresholds: \textbraceleft
1s2s$^{\mathrm{2}}$2p$^{\mathrm{6}}$3s$^{\mathrm{2}}$3p$^{\mathrm{5}}$
$^{\mathrm{3,1}}$P\textbraceright np $^{\mathrm{2}}$S, $^{\mathrm{2}}$P,
$^{\mathrm{2}}$D. The results show that the 1s$\to $3p resonances is by far
the strongest, as might be expected, and the energy and shape are in rather
good agreement with experiment [1]. Furthermore, this lowest
$^{\mathrm{2}}$S resonance ``robs'' oscillator strength from the resonances
of the \textbraceleft
1s2s$^{\mathrm{2}}$2p$^{\mathrm{6}}$3s$^{\mathrm{2}}$3p$^{\mathrm{5}}$
$^{\mathrm{3}}$P\textbraceright np $^{\mathrm{2}}$S series, which are very
much weaker than their $^{\mathrm{2}}$P and $^{\mathrm{2}}$D counterparts;
there is no 1s$\to $3p resonance in the $^{\mathrm{2}}$P and
$^{\mathrm{2}}$D manifolds. The next strongest resonances are the six 1s$\to
$4p excitations. Each pair $^{\mathrm{2}}$S, $^{\mathrm{2}}$P and
$^{\mathrm{2}}$D n$=$4 resonances interact so that their separation is not
the splitting of the $^{\mathrm{3}}$P and $^{\mathrm{1}}$P 1s ionization
thresholds, and their quantum defects are very much larger than the
asymptotic values and for the n$=$4, they are about 1.6 for the
$^{\mathrm{2}}$P and $^{\mathrm{2}}$D while for the $^{\mathrm{2}}$S they
are about 1.8, reflecting the fact that the n$=$4 $^{\mathrm{2}}$S
resonances are also strongly affected by the 1s3p$^{\mathrm{6}}$ resonance;
the higher resonances in all series exhibit quantum defects of about 0.9.
[1] W. C. Stolte, \textit{et al}, Phys. Rev. A \textbf{88}, 053425 (2013). Work supported
by U.S. DOE.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2017.DAMOP.D1.139