gJ Factors Research Articles

Fine- and hyperfine structure semi-empirical studies of atomic cobalt. Even-parity configurations system

We present the results of multiconfiguration semi–empirical calculations of the fine structure (fs) and the hyperfine structure (hfs) for the even-parity level system of atomic cobalt (Co I), using all available experimental data. These results were obtained using our proprietary software package designed for complex atom structure analysis. Through the iterative fine-structure calculation procedure, predictions of energy levels along with their Landé gJ factors and wave functions were obtained for each electronic state. Good agreement was achieved between the theoretical hyperfine structures and the experimental constants, which confirmed the validity of the propositions in the spectroscopic descriptions of observed Co I levels. For some levels no experimental hfs constants were known; in such cases these values are predicted.

Relativistic atomic structure calculations for B-like xenon ion

Excitation energies, transition parameters and lifetimes for 255 levels with n≤ 4 configurations of B-like Xe49+ are calculated using the fully relativistic multiconfiguration Dirac–Hartree–Fock (MCDHF) method. Hyperfine structure constants, isotope shift and Landé gJ factors are computed for the 2s22p,2s2p2 and 2p3 levels. The contribution of the Breit interaction and QED effects, mainly self-energy and vacuum polarization corrections, on these levels is also investigated. The uncertainties in the lifetimes and line strengths are computed, and transitions are classified according to the NIST accuracy nomenclature. A comparison with the previously available results is also carried out. This study provides extensive results for B-like Xe49+, which are useful for plasma diagnosis.

Zeeman spectroscopy of tellurium

The Zeeman structure of eight lines of 130Te covering the spectral range 640–990 nm was investigated. LandȨ gJ factors for seven levels were determined for the first time. Furthermore, we have performed the fine structure studies using abinitio multiconfiguration Dirac-Hartree-Fock calculations for levels of the ground 5p4 and excited 5p36s, 5p35d, 5p36p, 5p38s, 5p38d and 5p39d configurations. The results of the calculations were compared with available experimental data.

Calculations of energy levels, radiative transition parameters, hyperfine structure constants [formula omitted] - [formula omitted], Landé [formula omitted] factors and isotope shifts for Sc XX using the MCDF-RCI method

Large scale calculations for the energy levels, transition rates, oscillator strengths, lifetimes, hyperfine interaction constants, Landé gJ factors, and isotope shift factors have been performed for 1s2 and 1snl(n=2−8andl≤n−1) levels of He-like Sc XX ion. The general-purpose relativistic atomic structure package (GRASP2018) based on the fully relativistic multiconfiguration Dirac–Fock (MCDF) method is used to carry out the calculations. The leading quantum electrodynamic corrections, Breit interaction and nuclear recoil effects are also included in the succeeding relativistic configuration interaction (RCI) calculations. The relativistic isotope shift (RIS4) programme is used to determine the mass and field shifts factors. Furthermore, the percentage uncertainty in the transition parameters and lifetimes is estimated. A detailed comparison of the present results with the corresponding values from the NIST database and other theoretical and experimental works, wherever available, has been done, and an excellent agreement is achieved. A large section of the results is reported for the first time in the present work.

Fine- and hyperfine structure semi-empirical studies of singly ionised cobalt. Odd-parity configurations system

We present the results of semi–empirical calculations of the fine structure (fs) and the hyperfine structure (hfs) for the odd–parity level system of the cobalt ion (Co II), using all available experimental data. The performed calculations showed a very good agreement, within experimental uncertainty, between the total of 146 experimental hfs A values and the calculated values. An attempt was made to resolve significant discrepancies in some experimental results that were recently published by two research teams. The predicted energies of electronic levels, together with their Landé gJ factors as well as magnetic dipole Ahfs constants for unknown levels are also provided.

Fine- and hyperfine structure semi-empirical studies of singly ionised cobalt. Even-parity configurations system

We present the results of semi–empirical calculations of the fine structure (fs) and the hyperfine structure (hfs) for the even–parity level system of the cobalt ion (Co II), using all available experimental data. With the exception of three cases, there was very good agreement, within experimental uncertainty, between the total of 144 experimental hfs A values and the calculated values. An attempt was made to resolve significant discrepancies in some experimental results recently published by two research teams. The predicted energies of electronic levels together with their Landé gJ factors as well as magnetic dipole Ahfs constants for unknown levels are also provided.

Extended Calculations of Atomic Structure Parameters for Na-like Ar, Kr and Xe Ions Using Relativistic MCDHF and MBPT Methods

In this study, comprehensive calculations of energies, hyperfine structure constants, Landé gJ factors and isotope shifts have been performed for the lowest 71 states of Na-like Ar7+, Kr25+ and Xe43+ ions. Radiative parameters viz., wavelengths, transition rates, oscillator strengths and lifetimes are estimated for the electric dipole E1 transitions among these levels. The states under consideration include 1s22s22p6nl for n = 3–9, l = 0–6, and the fully relativistic multiconfiguration Dirac–Hartree–Fock (MCDHF) method integrated in the latest version of the general-purpose relativistic atomic structure package (GRASP2018) is used for the calculations. The additional corrections, such as the Breit interaction and quantum electrodynamics effects are included in the relativistic configuration interaction calculations, and their effects on energies and other parameters are analysed. We examined the impact of including the core–core and core–valence correlations on level energies. Furthermore, to inspect the reliability of our MCDHF results, we performed another set of calculations using the many-body perturbation theory built into the Flexible Atomic Code (FAC). Moreover, we estimated the uncertainties in the computed lifetimes and transition parameters and assigned their accuracy class. A thorough comparison between the two obtained calculations and with the previous theoretical and experimental results, wherever available, is carried out and a good agreement is observed.

Atomic Structure of Nd9+ for Highly Charged Ion Clocks

The energy levels arising from the electronic orbital 5p−4f crossing between the ground 5p24f and excited 5p4f2 configurations in the Nd9+ ion are investigated by using high-accuracy relativistic ab initio calculations. The accurate atomic data of the lifetime, gJ factor, electric quadrupole moment, and hyperfine structure of the magnetic dipole are also presented. The long-lived states that are suitable for making narrow-linewidth (milli-Hz) clock lines are found. Dominant systematics caused by stray electromagnetic interactions in an experiment and the coefficients of the relativistic sensitivityto variation of the fine-structure constant α and of the Lorentz invariance violation are evaluated, thus validating that the Nd9+ ion can be a new candidate for high-resolution spectroscopy and precision fundamental studies for probing new physics beyond the Standard Model.

Landé [formula omitted] factors of the odd-parity electronic levels of the terbium atom determined by laser spectroscopy

In the present work the experimentally determined values of Landé gJ factors for 20 odd-parity electronic levels of atomic terbium are presented. The Zeeman splitting of the hyperfine structure was investigated using the method of laser induced fluorescence in a hollow cathode discharge lamp in a constant magnetic field. All of the values were determined for the first time, by the analysis of 32 spectral lines, recorded in the spectral range between 492 and 609 nm. Moreover, the gJ factors for 15 even-parity energy levels, reported in the available literature, were verified.

Landé [formula omitted] factors of the even-parity electronic levels of the terbium atom

In the present work Landé gJ factors for 17 even-parity electronic levels of the terbium atom are presented. The spectra of the Zeeman splitting of the hyperfine structure were recorded with the method of laser spectroscopy in a hollow cathode discharge lamp in a constant magnetic field, with laser induced fluorescence detection. The analysis of 47 spectral lines of terbium in the spectral range between 490 and 609 nm enabled the determination of the gJ factors for the presented even-parity levels for the first time. Moreover, verification of the gJ factor values for 17 odd-parity levels, previously reported by other authors from the analysis of Fourier transform spectra.

Comprehensive Calculations of Energy Levels, Radiative Transition Parameters, Hyperfine Structure Constants Aj - Bj, Land´E Gj Factors and Isotope Shifts for Sc Xx

Comprehensive Calculations of Energy Levels, Radiative Transition Parameters, Hyperfine Structure Constants Aj - Bj, Land´E Gj Factors and Isotope Shifts for Sc Xx

Comprehensive Calculations of Energy Levels, Radiative Transition Parameters, Hyperfine Structure Constants Aj - Bj, Land´E Gj Factors and Isotope Shifts for Sc Xx

Comprehensive Calculations of Energy Levels, Radiative Transition Parameters, Hyperfine Structure Constants Aj - Bj, Land´E Gj Factors and Isotope Shifts for Sc Xx

Semi-empirical predictions of energy levels, their Landé [formula omitted] factors and hyperfine structure for the odd-parity configuration system of Ho II

We present the results of semi–empirical calculations of the fine (fs) and the hyperfine structure (hfs) for the odd–parity level system of the holmium ion (Ho II), using all available data. A parametric analysis, both for a fs and hfs, for 5 configurations with all the 4f10 and 4f11 core states, by taking into account the second–order effects of perturbation theory, was performed for the first time.The predicted energies of electronic levels together with their Landé gJ factors as well as magnetic dipole A and electric quadrupole Bhfs constants for unknown levels are listed.The importance of the Landé gJ factors in atomic and quantum physics, as well as a complete lack of experimental data on this subject, make our calculated values all the more useful.

Landé [formula omitted] factors of odd-parity electronic levels of the holmium atom

In the present work results of Landé gJ factors measurements for 18 electronic levels of the holmium atom are presented. Recorded Zeeman spectra of the hyperfine structure, observed with the method of laser spectroscopy in a hollow cathode discharge lamp, placed in constant magnetic field, with laser induced fluorescence detection, were analyzed. Results obtained for 33 spectral lines of holmium in the spectral range of 488-677nm enabled the determination of the corresponding gJ factors. For 12 odd-parity levels of Ho I and one even-parity level these factors are determined for the first time.

Landé [formula omitted] factors of the electronic levels of the holmium atom

In the present work measurements of Landé gJ factors for some electronic levels of the holmium atom are presented. The measurements were performed with the use of the Zeeman effect of the hyperfine structure, observed with the method of laser spectroscopy in a hollow cathode discharge lamp placed in constant magnetic field, with laser induced fluorescence detection. Investigation of 69 spectral lines of holmium in the spectral range 490–670 nm enabled for the first time the determination of gJ factors for 15 levels belonging to the odd-parity configurations of Ho and 18 levels belonging to the even-parity configurations.

Optogalvanic spectroscopy of the Zeeman structure of argon energy levels close to the ionization limit

The Lande gJ factors for high lying states of the argon atom by laser optogalvanic spectroscopy were measured, in most cases with an uncertainty of less than 0.005. The Zeeman structure of 12 argon lines with wavelengths in the range 598.7-612.8 nm was investigated. We determined Lande gJ factors for 9 odd parity levels and verified the data for several other levels.

Multiconfiguration Dirac–Hartree–Fock energy levels, weighted oscillator strengths, transitions probabilities, lifetimes, hyperfine interaction constants, Landé g-factors and isotope shifts of O VII

Energy levels, weighted oscillator strengths and transition probabilities, lifetimes, hyperfine interaction constants, Landé gJ factors and isotope shifts have been calculated for all levels of 1s2 and 1snl (n=2-8,l⩽7) configurations of He-like oxygen ion (O VII). The calculations were performed using the Multiconfigurational Dirac-Hartree–Fock (MCDHF) and the Relativistic Configuration Interaction (RCI) methods. A second set of calculations was obtained with the Many Body Perturbation Theory (MBPT) method. Transition probabilities are reported for all E1,E2,M1 and M2 transitions. Breit interactions and quantum electrodynamics effects were included in the RCI calculations. Comparisons have been made with the compiled data from the NIST ASD and other calculations and a good agreement was found which confirms the reliability of our results. The accuracy of the present calculations is high enough to facilitate identification of many observed spectral lines. For the first time, we present some missing data for the He-like oxygen ion.

Investigation of the Zeeman—hyperfine structure of atomic niobium

Laser spectroscopy was used for the investigation of the Zeeman-hf structure of 22 lines of atomic niobium in the visible region between 573.7 and 649.4 nm. We used two methods of laser absorption spectroscopy: laser induced fluorescence (LIF) method and optogalvanic spectroscopy (OG). The source of niobium atoms was a hollow cathode discharge tube. The magnetic field of approximately 800 G was generated by a permanent neodymium magnet. We determined experimentally for the first time the Lande gJ factors for 10 levels. We also verified earlier experimental data on the hf structure as well as data from the NIST database regarding Lande gJ factors.

Landé gJ factors of the electronic levels of the europium atom

In the present work measurements of Landé gJ factors for some electronic levels of the europium atom are presented. The measurements were performed with the use of the Zeeman effect of the hyperfine structure, observed with the method of laser spectroscopy in a hollow cathode discharge lamp placed in constant magnetic field, with laser induced fluorescence detection. Investigation of 54 spectral lines of europium in the spectral range 511–662 nm enabled for the first time the determination of gJ factors for 16 levels belonging to the odd-parity configurations of Eu and 4 levels belonging to the even-parity configurations. Moreover, 3 gJ values for levels belonging to the even-parity configurations, previously known from the literature, were corrected.

Investigations of the possible second-stage laser cooling transitions for the holmium atom magneto-optical trap

In this work laser-spectroscopic investigations of selected electronic levels in the holmium atom are performed in the context of possible second-stage laser cooling transitions which can be considered in a magneto-optical trap. Five transitions were directly recorded by the method of laser induced fluorescence in a hollow cathode discharge. The hyperfine structure constants A and B for the upper even-parity J=17/2 levels, evaluated in earlier works, were generally confirmed, and their accuracy was improved; thus the frequency differences between the hyperfine structure components, relevant for the possibility of application of the hyperfine repumping, could be determined. Investigations of the Zeeman-hyperfine structure of these spectral lines were performed in order to evaluate the Landé gJ factors of the upper levels; these were reported for the first time. Semi-empirical preliminary calculations of the lifetimes of the even-parity levels in question were also carried out, allowing estimation of the expected Doppler limits for the possible narrow-band laser cooling at the respective transitions. The degree of similarity between the gJ factors of the upper levels of the cooling transitions and the ground state is important for the efficiency of the sub-Doppler laser cooling in a magneto-optical trap. The results presented might facilitate the choice of the most favorable option of obtaining narrow-band laser cooling of the holmium atoms.