Hyperfine structure investigations in atomic iodine

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Highlights

  • Hyperfine structures of 50 lines were analyzed for iodine.

  • HFS constants of 54 levels were reported.

  • HFS constants of 10 levels were reported for the first time.

Abstract

Experimental results of the hyperfine structure (hfs) constants of levels of the iodine atom are reported. The absorption spectra of 50 transitions in the near infrared spectral region were observed using concentration modulation technique with a tunable single-mode cw Ti:Sapphire laser. Magnetic dipole hfs constants A and electric quadrupole hfs constants B for 54 levels were determined, out of which for 10 levels were examined for the first time, the constants were confirmed for 44 levels.

Introduction

Spectra and hfs of atomic iodine have been studied during many years. Tolansky [1], [2] determined the nuclear spin of the iodine atom to be 5/2 from spark and arc spectra of iodine. Eshbach and Fisher observed the spectrum of iodine in the region between 0.8 and 2.2 µm in 1954 [3] and found several energy levels. An extensive study of neutral iodine was finished by Kiess and Corliss in 1959 [4]. They obtained the spectra of atomic iodine in the wide region from 23,070 Å to 1195 Å. Spectra of iodine in the infrared region (1.8–4.0 µm) were observed and analyzed by Humphreys et al. in 1971 and 1972 [5], [6]. In 1975, Luc-Koenig et al. analyzed the hfs structure of 130 lines of the iodine atom [7]. In 2017, Chilukoti et al. added new hfs constants for 9 levels [9].

In a previous study, we investigated the spectral lines between 11300 cm1 and 13000 cm1 and determined the magnetic dipole constants and the electric quadrupole hyperfine structure constants (A and B) of 18 even levels and 28 odd levels [8]. In the present work, the spectra were re-measured with absorption line-shape and 50 transitions were analyzed. The hyperfine structure constants of 54 levels were determined and the constants of 10 levels were examined for the first time.

Section snippets

Experimental setup

The apparatus is the same as used in the previous studies [8], [10] of atomic iodine. A tunable Ti:sapphire ring laser (Coherent 899-29) working around 800 nm was used as the laser source. A glass tube with ring electrodes at both ends was filled with flowing helium at a dynamic pressure of 140 pa. The iodine vapor was derived from the heating of solid iodine inside. The electrodes were connected to an AC power supply working at 23 kHz, which produces the excited atomic iodine. The

Results and discussion

There is only one stable isotope, 127I, in the natural abundance of iodine. The nuclear spin quantum number is I = 5/2. The coupling of the electron (J) and nuclear (I) angular momentum induced by the hyperfine interaction forms the total angular momentum, i.e., F = J+I. Due to I = 5/2, there are up to 16 hyperfine components for each transition (if J ≥ I and ΔJ=0). Both the magnetic dipole coupling constant (A) and the electric quadrupole coupling constants (B) can be obtained by fitting the

Conclusion

In summary, we obtained the hfs constants of 54 levels of iodine atom based on the absorption spectra of 50 transitions measured using concentration modulation spectroscopy. The known hfs constants in literatures are verified and constants for 10 levels are newly reported.

Acknowledgments

This project was supported by the National Natural Science Foundation of China (Grant No.11674096).

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Cited by (4)

  • Hyperfine structure measurements of neutral atomic iodine (<sup>127</sup>I) in the infrared region (1800-6000 cm<sup>−1</sup>)

    2019, Journal of Quantitative Spectroscopy and Radiative Transfer
    Citation Excerpt :

    However, comprehensive details of the hyperfine spectra in the complete spectral range from infrared to UV are still missing. Using various spectroscopic techniques, spectra of neutral atomic iodine (I I) have been reported in the past [1–10] to determine nuclear spin, spectral line positions and hyperfine structure (hfs) constants [11–17] from the measured spectral line positions. A brief discussion of past studies of I I and the details of its hyperfine structure can be found in ref. [16–17].

  • Hyperfine structure measurements of neutral atomic iodine (<sup>127</sup>I) in near infrared and visible regions

    2018, Journal of Quantitative Spectroscopy and Radiative Transfer
    Citation Excerpt :

    In the case of even levels, hfs constants were derived for 48 levels. A and B constants for 37 levels were previously reported [10–13] and the remaining 11 levels were treated for the first time. Each of these 11 levels was involved only in one transition, therefore repeated measurements were carried out to derive A and B constants and the mean values are given for each level.

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