Graz University of Technology Institute of Experimental Physics
ABSTRACT
References
New Energy Levels of the Pr Atom found by
Analyzing a Fourier Transform Spectrum
Zaheer Uddin
1,2,
, L. Windholz
1
, G. H. Guthöhrlein
3
, Sumbul Zehra
2
, Saifuddin Jilani
2
1
Institute for Experimental Physics, Graz University of Technology, Petersgasse 16, 8010, Graz, Austria
2
Department of Physics, University of Karachi, Karachi, Pakistan
3
Universität der Bundeswehr Hamburg, Hamburg, Germany
Presenting Author: windholz@tugraz.at
The spectral line 7913.608
Å which leads to
24500.390 cm
-1
Using a high-resolution Fourier transform spectrum [1], prominent but up to now not classified spectral lines in near infrared spectral region, which showed sufficiently resolved hyperfine (hf) patterns, were studied. If the pattern of the line under investigation could be simulated reliably, we got from the hf structure the total angular momenta and hyperfine constants A of the involved levels (the quadrupole hyperfine constant B can be assumed to be zero). Searching now in our database of Pr levels for levels having proper J and A, we could identify one of the combining levels. The energy of the other one can be calculated using center of gravity (cg) wave number of the line. A newly found level must explain with high accuracy other spectral lines with respect to their cg wavelength and to the hyperfine pattern. Sometimes also energies and A of known levels were corrected. (e.g. level 21424.11 cm-1, J= 7/2, A = 435 MHz, as given in ref. [2], was changed to 21424.059 cm-1, J= 7/2, A = 502(3) MHz).
Some of the newly found levels are listed in Table 1, together with the explained lines.
Investigation of line 7929.918 Å
The line 7925.918 Å was known but was not classified . It blends with 7925.655 Å.
The best fit of the hyperfine structure of the line 7925.918 Å.
A known lower level (9464.440 cm-1) was identified using the hyperfine constant of the lower level obtained from the fitting process. The addition of center of gravity wave number (12613.366 cm-1) to
energy of the identified lower gave the energy of the new upper level.
The introduction of the newly discovered upper level in the level list of Pr explained not only the observed fluorescence lines but two more lines in the transition list for the upper level calculated by
the classification program.
J = 11/2, Parity = odd, 22077.806 cm
-1
, 1038(4) MHz
Lines explained by new level 21438.488 cm
-1
Table 1:
List of Lines explained by new levels
11184.396 cm-1
10841.407 cm-1
11274.229 cm-1
10904.034 cm-1
8829.063 cm-1
6714.184 cm-1
9675.029 cm-1
8643.824 cm-1
9268.726 cm-1
9/2, odd
21438.488 cm-1
8214.829 Å 7928.395 Å
6789.618 Å 7813.607 Å
9835.661 Å 9433.968 Å
9749.525 Å
9490.053 Å
8498.565 Å
7925.918 Å 7925.655 Å
Lines explained by new level 22077.806 cm
-1
6919.618
Å
5665.569
Å
Correction in energy and A value of the level 21424.11 cm
-1
A- Value =502 MHz
C.G. wavenumber = 13013.819 cm
-1,
Energy of lower level = 8320.240 cm
-1Energy of upper level = 21424.059 cm
-1[1] B.Gamper, Z.Uddin, M. Jahangir, O. Allard, H. Knöckel, E.Tiemann and L.Windholz, J.Phys.B. At. Mol. Opt. Phys., 44 (2011) 045003 (7pp)
[2] A. Ginibre, PhD thesis, Universite de Paris (1988)
