EGAS41 - Swansea University

41 st EGAS CP 17 Gdańsk 2009
New view on the description of the hyperfine structure of free
atoms and ions. Case of the model space (5d + 6s) 3 of
lanthanum atom
J. Dembczyński ∗ , M. Elantkowska, J. Ruczkowski
Chair of Quantum Engieneering and Metrology, Poznań University of Technology Nieszawska
13B, PL 60-965 Poznań, Poland
∗ Corresponding author: jerzy.dembczynski@put.poznan.pl
On the basis of our earlier works, both experimental and theoretical [1,2], as well as numerous
works by other authors we feel qualified to submit a proposition, that the existing
theories, which provide a semi-empirical description of hyperfine interactions in the structure
of a complex atom, are not sufficiently precise to yield a correct interpretation of the
measured hyperfine splittings within the up-to-date experimental accuracy.
In our group a procedure of analysis of experimental data concerning the structure of
complex atoms, was developed. In the updated procedure the segment ”parametrization
of one- and two-body hyperfine interactions” was improved with respect to the earlier
applied method [2,3] through inclusion of full parametrization of the excitations from
closed shells to open shells, as well as generalization allowing parametrization of twobody
hyperfine interactions in all really existing configurations up to three open shells.
In the case of lanthanum atom, the configuration system (5d+6s) 3 is well separated
from the other perturbing configurations. This fact allows to analyse alternative models
of second order perturbations, taking into account ”open shell - empty shell” or ”closed
shell - open shell” excitations.
By comparison of the results of both models for the fine and the hyperfine structure,
we can verify correctness of description of atomic structure and precisely determine information
included in the radial parameters calculated on the basis of experimental data
[4,5].
Acknowledgment
This work was supported by Polish Ministry of Science and Higher Education under the project
N519 033 32/4065.
References
[1] J. Dembczyński, G.H. Guthöhrlein, E. Stachowska, Phys. Rev. A 48, 2752 (1993)
[2] J. Dembczyński, Phys. Scripta T65, 88 (1996)
[3] J. Dembczyński, W. Ertmer, U. Johann, P. Unkel, Z. Phys. A 321, 1 (1985)
[4] W.J. Childs, L.S. Goodman, Phys. Rev. A 3, 25 (1971)
[5] W.J. Childs, U. Nielsen, Phys. Rev. A 37, 6 (1988)
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