EGAS41 - Swansea University

41 st EGAS CP 57 Gdańsk 2009
Investigation of lowest autoionizing states of Cs
A. Kupliauskienė 1∗ , A. Borovik 2 , Keh-Ning Huang 3
1 Institute of Theoretical Physics and Astronomy of Vilnius University, A.Goštauto 12, Vilnius,
LT-01108, Lithuania
2 Department of Electron Processes, Institute of Electron Physics,Uzhgorod, 88017, Ukraine
3 Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei,
Taiwan 106, Republic of China
∗ Corresponding author: akupl@itpa.lt
For the identification of recently measured ejected-electron excitation function for the
5p 5 n 1 l 1 n 2 l 2 LSJ autoionizing levels [1] of Cs atoms exited by electron impact, the calculations
of the energy levels, excitation cross sections, autoionization probabilities as
well as probabilities of the radiative transitions to the ground and among autoionizing
states were made. In the case of Cs, the relativistic effects play more important role in
comparison to the lighter atoms Na and K. Therefore, quasi-relativistic (Cowan) [2] and
multiconfiguration Dirack-Fock (FAC) [3] computer codes were used. The structure of
energy spectrum reveals the overlap of the lines arising from 5p 5 6s 2 , 5p 5 5d6s, 5p56s6p
and 5p 5 6s7s configurations. The lowest energy levels calculated by using configuration
interaction (CI) approximation are presented in Table 1.
Table 1: Energy levels (in eV) of the lowest states 5p 5 6s 2 LSJ and 5p 5 5d(L 1 S 1 )6sLSJ for Cs
with respect to the ground state.
LSJ FAC Cowan Exp [1] LSJ FAC Cowan Exp [1]
6s 2 2 P 3/2 12.24 12.23 12.31 ( 3 P) 4 P 5/2 13.09 12.94 13.20
( 3 P) 4 P 1/2 12.75 12.54 12.78 ( 3 F) 4 F 7/2 13.11 13.06
( 3 P) 4 P 3/2 12.91 12.68 12.93 ( 3 P) 4 S 3/2 13.15 12.99 13.34
( 3 F) 4 F 9/2 13.08 12.94 6s 2 2 P 1/2 14.10 14.04 14.07
Acknowledgment
The study was partially funded by the Joint Research Taiwan-Baltic project and the grant for
collaboration between Lithuania and Ukraine.
References
[1] A. Borovik, O. Zatsarinny, K. Bartschat, J. Phys. B 42, 044010 (2009)
[2] R.D. Cowan, The Theory of Atomic Structure and Spectra (University of California,
1981)
[3] M.F. Gui, http://kipac-tree.stanford.edu/fac
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