EGAS41 - Swansea University

41 st EGAS CP 163 Gdańsk 2009
Investigation of the hyperfine structure of Ta I-lines
by laser-induced fluorescence
P. G̷lowacki 1,2∗ , J. Dembczyński 1 , L. Windholz 2
1 Chair of Quantum Engineering and Metrology, Poznań University of Technology,
ul. Nieszawska 13B, 60-965 Poznań, Poland
2 Institute of Experimental Physics, Graz University of Technology,
Petersgasse 16, A-8010 Graz, Austria
∗ Corresponding author: Przemyslaw.Glowacki@put.poznan.pl
Systematic investigations of the hyperfine structure of spectral lines of neutral tantalum
have been performed by our international collaboration group since the beginning of 90’s
of the 20 th century[1].
In 1997, a theoretical analysis of the even tantalum energy levels in the configurations
system (5d + 6s) 5 [2] showed that the knowledge of the electronic structure of tantalum
atom was far from being complete. But even after discovery of a large number of even energy
levels [3,4], most of them filling gaps in the mentioned theoretical analysis, predicted
levels remain which were never found.
That was the main reason to continue investigations of tantalum spectral lines by LIF
(Laser-Induced Fluorescence) method in the spectral range covered by a coumarine 102
dye laser (4700 - 5100 Å), which had not been yet thoroughly studied. Previously only
few lines were investigated and reported in this range [5-7].
In this work we report the discovery of 1 new energy level of even parity and 1 new
energy level of odd parity. For new levels, beside their wave number, their total angular
momentum quantum number J, their parity, as well as their magnetic dipole and electric
quadrupole hyperfine interaction constants A and B were determined. All data for new
levels are listed in table 1. We classified altogether 22 lines by means of laser spectroscopy
in a hollow cathode discharge, 17 of them by laser excitation and 5 via fluorescence decay.
These results are presented within this work.
Table 1: Parameters of the new Ta I levels.
Parity J Energy / cm −1 A / MHz B / MHz λ ex (air) / Å
even 9/2 54496.666(6) 210(8) 250(100) 4760.680
odd 1/2 47418.095(11) -661(13) 0 4835.614, 4997.192
Acknowledgment
This work was performed within the framework of DS63-029/09.
References
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152 (1997)
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H. Jäger, G.H. Guthöhrlein, L. Windholz, Phys. Scr. 68, 170-191 (2003)
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