The hyperfine (hf) structure constants of three atomic niobium energy levels in the energy range around 23000 cm-1 (at 22936.90, 23010.58, and 23048.58 cm-1) are known with only limited accuracy, and the constants of combining levels are sometimes even unknown. Thus we performed laser spectroscopic investigations in the wavelength range between 5600 and 6500 Å, and we excited altogether 16 transitions in which these lower levels are involved. Beside a more precise determination of the hf structure constants of the three lower levels (which were determined on several lines sharing a common upper level), these experiments led to the knowledge of the hf constants of nine levels with previously unknown constants. Beside these results, also the hf constants of 13 further energy levels are reported. For six of these levels, the constants were previously unknown.
References
[1]
Raghavan, P. (1989) Table of Nuclear Moments. Atomic Data and Nuclear Data Tables, 42, 189. https://doi.org/10.1016/0092-640X(89)90008-9
[2]
Humphreys, C.J. and Meggers, W.F. (1945) Term Analysis of the First Two Spectra of Columbium. Journal of Research of the National Bureau of Standards, 34, 478-588. https://doi.org/10.6028/jres.034.028
[3]
Moore, C.E. (1958) Atomic Energy Levels. Vol. 2, NSRDS-NBS (Washington, DC: Government Printing Office) 35.
[4]
Kröger, S., Scharf, O. and Guthöhrlein, G. (2004) New and Revised Energy Levels of Atomic Niobium. Europhysics Letters, 66, 344-349.
https://doi.org/10.1209/epl/i2003-10209-9
[5]
Kröger, S., Ötztürk, I.K., Acar, F.G., Başar, G.C., Başar, G. and Wyart, J.-F. (2007) Fine and Hyperfine Structure in the Atomic Spectrum of Niobium. Theoretical Analysis of the Odd Configurations and Further New Levels. European Physical Journal D, 41, 61-70. https://doi.org/10.1140/epjd/e2006-00207-0
[6]
Ötztürk, I.K., Başar, G., Er, A., Güzelçimen, F., Başar, G. and Kröger, S. (2015) New Energy Levels of Atomic Niobium by Laser-Induced Fluorescence Spectroscopy in the Near Infrared. Journal of Physics B, 48, 015005.
https://doi.org/10.1088/0953-4075/48/1/015005
[7]
Büttgenbach, S., Dicke, R., Gebauer, H., Herschel, M. and Meisel, G. (1975) Hyperfine Structure of Nine Levels in Two Configurations of 93Nb. Zeitschrift für Physik A Atoms and Nuclei, 275, 193-196. https://doi.org/10.1007/BF01409283
[8]
Fraenkel, L., Bengtsson, C., Hanstrop, D., Nyberg, A. and Persson, J. (1988) Hyperfine Structure Measurements of 93Nb. Zeitschrift für Physik D Atoms, Molecules and Clusters, 8, 171-176. https://doi.org/10.1007/BF01384510
[9]
Singh, R. and Rao, G.N. (1989) Hyperfine Structure Studies of Niobium Using Laser Optogalvanic Spectroscopy. Physica Scripta, 40, 170
http://doi.org/10.1088/0031-8949/40/2/005
[10]
Singh, R., Thareja, R.K. and Rao, G.N. (1992) Hyperfine-Structure Studies of 93Nb by Laser Optogalvanic Spectroscopy. Journal of the Optical Society of America B, 9, 493-497. http://doi.org/10.1364/JOSAB.9.000493
[11]
Lauranto, H.M., Auterinen, I.H., Kajava, T.T., Nyholm, K.M. and Salomaa, R.R.E. (1990) Determination of Hyperfine Structures and Rydberg Convergence Limits of Selected Optical Transitions in 93Nb Using Resonance Ionization Spectroscopy. Applied Physics B, 50, 323-329. http://doi.org/10.1007/BF00325067
[12]
Bouzed, A., Kröger, S., Zimmermann, D., Kronfeldt, H.-D. and Guthöhrlein, G.H. (2003) Hyperfine Structure in the Atomic Spectrum of Niobium. I: Experimental Investigation. European Physical Journal D, 23, 57-62.
https://doi.org/10.1140/epjd/e2003-0026-8
[13]
Kröger, S. and Bouzed, A. (2003) Hyperfine Structure in the Atomic Spectrum of Niobium. II: Theoretical Analysis of the Even Configurations. European Physical Journal D, 23, 63-72. https://doi.org/10.1140/epjd/e2003-0027-7
[14]
Kröger, S. (2007) Further Experimental Investigation of the Hyperfine Structure in the Spectrum of Atomic Niobium. European Physical Journal D, 41, 55-59.
https://doi.org/10.1140/epjd/e2006-00206-0
[15]
Başar, G., Başar, G., Burcin Bayram, S. and Kröger, S. (2008) High-Resolution Laser Spectroscopy of the Hyperfine Structure of High-Lying Levels of Nb I. Physica Scripta, 78, 015303. https://doi.org/10.1088/0031-8949/78/01/015303
[16]
Kröger, S., Er, A., Ötztürk, I.K., Başar, G., Jarmola, A., Ferber, R., Tamanis, M. and Začs, L. (2010) Hyperfine Structure Measurements of Neutral Niobium with Fourier Transform Spectroscopy. Astronomy Astrophysics, 516, A70.
https://doi.org/10.1051/0004-6361/200913922
[17]
Er, A., Ötztürk, I.K., Başar, G., Kröger, S., Jarmola, A., Ferber, R. and Tamanis, M. (2011) Hyperfine Structure Study of Atomic Niobium with Enhanced Sensitivity of Fourier Transform Spectroscopy. Journal of Physics B, 44, Article ID: 205001.
https://doi.org/10.1088/0953-4075/44/20/205001
[18]
Başar, Gö., Başar, Gü., Ötztürk, I.K., Er, A., Güzelçimen, F. and Kröger, S. (2013) Hyperfine Structure Investigations of Atomic Niobium with Optogalvanic and Laser-Induced Fluorescence Spectroscopy in the Near-Infrared Wavelength Range. Astronomy Astrophysics, 556, A103. https://doi.org/10.1051/0004-6361/201321919
[19]
Dembczyński, J., Elantkowska, M., Ruczkowski, J., Ötztürk, I.K., Er, A., Güzelçimen, F., Başar, Gö. and Kröger, S. (2015) Parametric Study of the Fine and Hyperfine Structure for the Even Parity Configurations of Atomic Niobium. Journal of Physics B, 48, Article ID: 015006. https://doi.org/10.1088/0953-4075/48/1/015006
[20]
Er, A., Güzelcimen, F., Başar, Gö., Ötztürk, I.K., Tamanis, M., Ferber, R. and Kröger, S. (2015) High-Resolution Fourier Transform Spectroscopy of Nb I in the Near-Infrared. The Astrophysical Journal Supplement Series, 221, 14.
https://doi.org/10.1088/0067-0049/221/1/14
[21]
Kröger, S., Windholz, L., Başar, Gü. and Başar, Gö. (2018) New Energy Levels of Atomic Niobium (Nb I) Discovered by Laser-Spectroscopic Investigations. Journal of Quantitative Spectroscopy and Radiation Transfer, 212, 24-31.
https://doi.org/10.1016/j.jqsrt.2018.03.017
[22]
Windholz, L., Gamper, B., Głowacki, P. and Dembczyński, J. (2014) The Puzzle of the La I Lines 6520.644 Å and 6519.869 Å. Spectral Analysis Reviews, 2, 10-18.
https://doi.org/10.4236/sar.2014.23024
[23]
Windholz, L., Gamper, B. and Binder, T. (2016) Variation of the Observed Width of La I Lines with the Energy of the Upper Excited Levels, Demonstrated on Previously Unknown Energy Levels. Spectral Analysis Reviews, 4, 23-40.
https://doi.org/10.4236/sar.2016.43003
[24]
Windholz, L. and Guthöhrlein, G.H. (2003) Classification of Spectral Lines by Means of Their Hyperfine Structure. Application to Ta I and Ta II Levels. Physica Scripta, T105, 55. https://doi.org/10.1238/Physica.Topical.105a00055
[25]
Windholz, L. (2016) Finding of Previously Unknown Energy Levels Using Fourier-Transform and Laser Spectroscopy. Physica Scripta, 91, Article ID: 114003.
https://doi.org/10.1088/0031-8949/91/11/114003
[26]
Guthöhrlein, G.H. (1998) Program Package “Fitter”. Helmut-Schmidt-Universität, Universität der Bundeswehr, Hamburg, Germany, unpublished.
