Investigation Of Hyperfine Structure Research Articles

Hyperfine Structure Investigation of Singly Ionized Thulium in Fourier-transform Spectra

The hyperfine structure of 40 spectral lines of singly ionized thulium (Tm ii) in emission spectra from a hollow cathode discharge lamp measured with a Fourier transform spectrometer in the wavelength range from 335 to 2345 nm has been investigated. As a result of the analysis, the magnetic dipole hyperfine structure constants A for 27 fine structure levels of Tm ii were determined for the first time. In addition, the values of two magnetic dipole hyperfine structure constants A from the literature were declared incorrect, and the corrected values were given.

Hyperfine structure measurements on a forbidden transition of Bi I using fourier transform spectroscopy

Hyperfine structure (hfs) investigations have been performed on a forbidden transition of the Bi I emission spectral line in the visible region at 15,437.49 cm−1, between the levels 6p3 4S3/2 and 6p3 2D5/2, by means of a Fourier Transform spectrometer. Electrodeless discharge lamps (EDL) containing BiI3 were utilized to generate the bismuth plasma. In these observations, all the 6 components of electric quadrupole (ΔF = ±2) transitions have been detected for the first time, in addition to the 12 components of magnetic dipole (ΔF = 0, ±1) transitions. Magnetic dipole constant (A) and electric quadrupole constant (B) have been derived for the combining levels.

Hyperfine structure investigations of the odd-parity electronic levels of the terbium atom

In the present work the hyperfine structure constants A and B were determined for 26 odd-parity energy levels of the terbium atom. Altogether 62 spectral lines in the spectral range between 483 - 538 nm were examined, using the method of laser induced fluorescence in a hollow cathode discharge lamp. All the results are presented for the first time. Additionally, the constants for 4 even-parity energy levels, previously reported by our research group, were reevaluated and slightly corrected.

Hyperfine structure investigations of Mn I

In this work the hyperfine structure (hfs) of 30 spectral lines of the manganese atom was investigated with the method of laser induced fluorescence in a hollow cathode discharge with spectral selection of the fluorescence channels. As a result, the hyperfine structure constants A and B for altogether 12 odd-parity and 16 even-parity levels were determined. For 3 odd-parity and 15 even-parity levels the A and B values are reported for the first time, for another 8 levels new constants B were evaluated, and for the remaining 8 levels the accuracy of the hitherto available literature data was improved; in some cases, where discrepancies between the earlier experimental results, obtained by other authors, and the theoretical predictions were observed, the new data constituted an unequivocal verification, which data are correct. The available database of the hyperfine structure constants for the manganese atom was thus further extended. Semi-empirical parametrization of the hyperfine structure for the even-parity level system of the atomic manganese were also performed in the present work; the consistency between the experimental and semi-empirically predicted hfs constants was found generally satisfactory, and in many cases even very good.

New odd-parity energy levels of the neutral lanthanum atom

The discovery of 22 new energy levels of the La atom, having odd parity, is reported. These levels were derived from an analysis of unclassified spectral lines found either in optogalvanic spectra and/or Fourier transform spectra. The reliability of results obtained from the combination principle of Ritz was verified by hyperfine structure investigations. Further three new odd-parity levels of the first La ion are found. For two already known odd-parity levels substantial changes, concerning total angular momentum and hyperfine structure constants A, must be made.

Hyperfine structure of rovibrational quadrupole transitions in HD

We perform a theoretical investigation of hyperfine structure of all rovibrational quadrupole transitions in the ground electronic 1Σ+ state of the HD molecule. We determine positions and intensities of 185 631 hyperfine components of 7 251 quadrupole rovibrational transitions from the O, Q and S branches. Moreover, we provide a list of hyperfine splittings of all bound states in the six isotopologues of hydrogen which we considered in previous papers. The results reported here are necessary for a reliable interpretation of accurate experimental studies of rovibrational transition frequencies in the HD isotopologue, which are useful for tests of quantum electrodynamics for molecules and searches for new physics beyond the Standard Model.

Fine- and hyperfine structure investigations of the odd-parity configuration system in atomic holmium

In this work a parametric study of the fine (fs) and the hyperfine structure (hfs) for the odd-parity level system in the holmium atom (Ho I) is presented. A large amount of new experimental data, published in the last three years, have been considered for the fs and hfs semi-empirical analysis. Multiconfiguration calculations, both for the fine and the hyperfine structure, for 11 configurations with all the 4fN core states, by taking into account the second-order of perturbation theory, have been performed for the first time. Predicted values of level energies as well as magnetic dipole and electric quadrupole A and B hfs constants are listed. These values are of special interest if no experimental values are available. Some important information concerning the electronic structure of the holmium atom for further calculations of elements with open 4f electronic shell has been achieved.

Hyperfine structure measurements on singly ionized atomic iodine (I II) using fourier transform spectroscopy

Hyperfine structure (hfs) investigations were performed on singly ionized atomic iodine (I II) in the spectral region 12,000 - 24,000 cm−1, utilizing microwave discharge method in combination with high resolution Fourier Transform Spectroscopy (FTS). Electrodeless discharge lamps (EDL) were used to generate the iodine plasma. In the present work, 141 hyperfine spectral transitions are reported. Hfs measurements were carried out on 73 well resolved spectral lines and derived the magnetic dipole constant (A) and electric quadrupole constant (B) for 61 energy levels (29 even parity and 32 odd parity). Further, a magnetic dipole transition (14,366 cm−1) and a blended line (20,611 cm−1) have been observed.

Hyperfine structure measurements of neutral atomic iodine (127I) in near infrared and visible regions

Hyperfine structure (hfs) investigations were performed on neutral atomic iodine (II) in the near-infrared and visible spectral regions. Fourier transform spectroscopy to investigate the emission spectrum of a microwave driven electrodeless discharge lamp operated in a mixture of iodine vapor and Ne gas. In the present investigations, the observation of 240 hyperfine resolved spectral lines were reported. Hfs analysis was carried out on 128 spectral lines for the first time and repeated on 49 spectral lines. The magnetic dipole constant (A) and electric quadrupole constant (B) were derived for 100 energy levels. Among the 100 energy levels, A and B constants for 18 levels were presented for the first time.

Hyperfine structure investigations in atomic iodine

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.

Fine- and hyperfine structure investigations of the even-parity configuration system of the atomic holmium

In this work new experimental results concerning the hyperfine structure (hfs) for the even-parity level system of the holmium atom (Ho I) were obtained; additionally, hfs data obtained recently as a by-product in investigations of the odd-parity level system were summarized. In the present work the values of the magnetic dipole and the electric quadrupole hfs constants A and B were determined for 24 even-parity levels, for 14 of them for the first time. On the basis of these results, as well as on available literature data, a parametric study of the fine structure and the hyperfine structure for the even-parity configurations of atomic holmium was performed. A multi-configuration fit of 7 configurations was carried out, taking into account second-order of the perturbation theory. For unknown electronic levels predicted values of the level energies and hfs constants are given, which can facilitate further experimental investigations.

Hyperfine structure investigations for the odd-parity configuration system in atomic holmium

In this work new experimental results of the hyperfine structure (hfs) in the holmium atom are reported, concerning the odd-parity level system. Investigations were performed by the method of laser induced fluorescence in a hollow cathode discharge lamp on 97 spectral lines in the visible part of the spectrum. Hyperfine structure constants: magnetic dipole - A and electric quadrupole - B for 40 levels were determined for the first time; for another 21 levels the hfs constants available in the literature were remeasured. Results for the A constants can be viewed as fully reliable; for B constants further possibilities of improving the accuracy are considered.

Fine- and hyperfine structure investigations of even configuration system of atomic terbium

In this work a parametric study of the fine structure (fs) and the hyperfine structure (hfs) for the even-parity configurations of atomic terbium (Tb I) is presented, based in considerable part on the new experimental results. Measurements on 134 spectral lines were performed by laser induced fluorescence (LIF) in a hollow cathode discharge lamp; on this basis, the hyperfine structure constants A and B were determined for 52 even-parity levels belonging to the configurations 4f85d6s2, 4f85d26s or 4f96s6p; in all the cases those levels were involved in the transitions investigated as the lower levels. For 40 levels the hfs was examined for the first time, and for the remaining 12 levels the new measurements supplement our earlier results. As a by-product, also preliminary values of the hfs constants for 84 odd-parity levels were determined (the investigations of the odd-parity levels system in the terbium atom are still in progress). This huge amount of new experimental data, supplemented by our earlier published results, were considered for the fine and hyperfine structure analysis. A multi-configuration fit of 7 configurations was performed, taking into account second-order of perturbation theory, including the effects of closed shell-open shell excitations. Predicted values of the level energies, as well as of magnetic dipole and electric quadrupole hyperfine structure constants A and B, are quoted in cases when no experimental values are available. By combining our experimental data with our own semi-empirical procedure it was possible to identify correctly the lower and upper level of the line 544.1440nm measured by Childs with the use of the atomic-beam laser-rf double-resonance technique (Childs, J Opt Soc Am B 9;1992:191–6).

Hyperfine structure investigations of atomic niobium with optogalvanic and laser-induced fluorescence spectroscopy in the near-infrared wavelength range

Aims. The aim of this work is to increase the amount of hyperfine structure data of atomic niobium (Nb I), which is needed for astrophysicists for the detailed analysis of new stellar spectra. Particular emphasis was placed on the investigation of energy levels with unknown hyperfine structure constants. Methods. The hyperfine structure in the spectrum of Nb I was studied using laser-induced fluorescence spectroscopy and laser optogalvanic spectroscopy with a tuneable single-mode cw Ti:Sa laser in the wavelength range from 750 nm to 865 nm. The Nb atoms were produced and excited in a liquid-nitrogen-cooled hollow-cathode plasma. Results. We measured and analysed 81 spectral lines, 19 of which are not previously known from the literature. In total, the magnetic dipole hyperfine structure constants A were determined for 28 energy levels of even and 53 energy levels of odd parity. The electric quadrupole hyperfine structure constants B were only determined in a few cases, when the spectra were clearly resolved and/or when a level was found from several transitions. The magnetic dipole hyperfine structure constants A of 13 even and 11 odd levels as well as the electric quadrupole hyperfine structure constants B of 13 even and 17 odd levels are presented for the first time. For the other levels, improved values of hyperfine structure constants are given. Conclusions. The hyperfine structure can have a significant effect on stellar absorption line profiles, and the corresponding abundances can be substantially overestimated if these effects are not taken into account. Therefore, a detailed consideration of the hyperfine structure is important for stellar abundance determinations. The present work substantially increases the knowledge of hyperfine structure of Nb, which plays an important role in investigating the nucleosynthesis of heavy elements.

Investigations of hyperfine structure and isotope shift predictions in Hf II

AbstractThe fine structure of the even‐parity low configurations of singly ionized hafnium has been reanalyzed by simultaneous parameterization of the one‐ and two‐body interactions for the model space (5d + 6s)3. Using the calculated eigenfunctions, the magnetic‐dipole A hyperfine constants for the whole 37 existing levels of the model space were predicted and compared partially with those obtained using relativistic configuration‐interaction approach. Moreover, combined with experimental data, previously given in the literature, and pseudo‐relativistic Hartree–Fock estimates, the field shifts (FSs) and specific mass shifts (SMSs) of numerous configurations are deduced: FS(5d16s2) = 2265 MHz, FS(5d3) = −1958 MHz, FS(5d16p2) = −1696 MHz, FS(6s26p1) = 3135 MHz, and SMS(5d16s2) = −78 MHz, SMS(5d3) = 64 MHz, SMS(6s26p1) = −228 MHz, referred to 5d26s for the pair 178Hf–180Hf. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012

Hyperfine structure investigation of 187Os atomic levels via optical–optical double resonance

Optical–optical double resonance spectroscopy has been applied to measure the hyperfine structure of spectral line pairs of atomic osmium in the visible wavelength range. In the experiments, enriched isotope samples of either 189Os or 187Os were used. In this way, the magnetic dipole hyperfine interaction constants of the odd isotope 187Os were determined for seven levels of even parity and two levels of odd parity.

Hyperfine structure investigation of Sc I, part II: theoretical studies of the odd configurations

Based on the experimental hyperfine structure data given in our previous study, the multi-configuration method has been used to calculate the fine structure of the odd parity configurations 3d4s4p, 4s2 4p and 3d2 4p of neutral Scandium taking into account configuration interaction effects. Magnetic dipole hyperfine structure constants are analysed in the effective-operator formalism for the isotope 45Sc. Relativistic one-electron parameters of the magnetic dipole hyperfine structure anlkskl(kskl= 01, 10, 12) were fitted to the experimental data by a least-squares fit procedure. Theoretical predictions for the magnetic dipole hyperfine structure constants A for all levels of the three configurations are given.

Experimental hyperfine structure investigation of atomic La

Optogalvanic laser spectroscopy has been applied to measure the hyperfine structure of 19 spectral lines of La I in the wavelength regions from 570 to 590 nm and 700 to 825 nm. Experimental hyperfine structure constants A and B of the isotope139La have been measured for 16 levels of odd parity. From those values six magnetic dipole and ten electric quadrupole constants have been determined for the first time. Some disagreements with previously obtained values are discussed.

Hyperfine Structure Investigation of Mn I Part II: Theoretical Studies of The Odd Configurations

The parametric method has been used to calculate the fine structure of the odd configurations 3d54s4p, 3d54s5p and 3d64p of Mn I taking into account configuration interaction effects. Based on the results of the fine structure calculations and recent experimental hyperfine structure data, the magnetic dipole hyperfine structure is analysed using the effective-operator formalism. One-electron parameters anlkskl (kskl = 01, 10, 12) were determined for the three configurations and theoretical predictions for the magnetic dipole hyperfine structure constants A for all levels of these configurations up to 52 000 cm-1 are given.

Study of hyperfine structure in the optical spectra of crystals doped with Pr3+ and Er3+ ions

This paper reviews the author's recent work on the investigation of hyperfine structure in the optical spectra of crystals doped with rare-earth ions, using high-resolution Fourier spectroscopy. The features of the hyperfine structure are discussed for dimeric Pr3+ centers in the one-dimensional CsCdBr3 crystal and for Er3+ (an ion with an odd number of electrons) in LiYF4. © 2004 Optical Society of America