Laserspectroscopic Investigation of the Hyperfine Structure of Ta II-lines

Abstract

The hyperfine structure of 39 lines of the singly charged tantalum ion was investigated by means of dopplerlimited laser spectroscopy. From the spectra we have deduced the magnetic hyperfine interaction constants A and the electric quadrupole interaction constants B of 22 levels with even parity and 17 levels with odd parity.

Full hyperfine structure study of singly ionized tantalum

“…The spin-orbit integrals ζ 5d also effect the interactions with distant configurations. The interaction effects with distant configurations influencing the term structure have been taken into account by the three-body T (d 2 s), T 2 (22) and T 3 (42) and two-body parameters α and β representing the one-and two-electron excitations, respectively. The effects of the one-electron excitation on the spin-orbit splitting of the term (electrostatically correlated spin-orbit interaction) were considered in the way reported in [13].…”

“…In 2002 and 2003 three groups [19][20][21], located in Lund, London and Graz have studied the hfs of Ta II by analysing Fourier transform spectra (FTS). At the same time the hfs of 39 lines of the singly charged tantalum ion was investigated thanks to Doppler limited laser spectroscopy [22]. So, the number of A or B experimental hfs values is bigger than the number of one-and two-body parameters required by theory and then no additional assumptions had to be included in our hfs fitting procedure.…”

“…So, the number of A or B experimental hfs values is bigger than the number of one-and two-body parameters required by theory and then no additional assumptions had to be included in our hfs fitting procedure. We would rather have preferred to use only the whole data obtained by means of laser spectroscopy [22] and just some few selected results, mentioned as first quality class in table 2 of [19], got thanks to FTS. So, due to the good resolution of the recorded spectra an unambiguous determination of the Aand B-factors was possible: Fourier transform (FT) has a lot of advantages over other spectroscopic techniques: one can record thousands of lines by one scan.…”

The Role of the Hyperfine Structure for the Determination of Improved Level Energies of Ta II, Pr II and La II

“…Eriksson et al [19] investigated in 2002 the Ta II spectrum with respect to applications in astrophysics. Laser spectroscopic determinations of the hf constants of Ta II were performed by Messnarz and Guthöhrlein [20,21] at approximately the same time. During work on his thesis, Messnarz discovered some new energy levels of Ta II and could correct some incorrect classifications.…”

New levels of Ta II with energies higher than 72,000 cm −1

“…Messnarz discovered in his PhD work some new Ta II levels and corrected some classifications by means of laser spectroscopy. He also determined the hf constants of several Ta II levels with high accuracy [7,8]. Zilio and Pickering analyzed a FT spectrum and could give a number of hf constants for levels, for which these numbers were not known before [9].…”