Magnetic Dipole Constants Research Articles

The spin-vibration hyperfine interaction in the ν3 band of 189OsO 4 and 187OsO 4: a calculable example in high-resolution molecular spectroscopy

Osmium tetroxide offers the beautiful example of a central particle, the osmium nucleus, with several possible spin values (1/2 for 187Os and 3/2 for 189Os), interacting with the very symmetric and well-defined electromagnetic environment created by a tetrahedron of spinless oxygen nuclei. Among other nuclear hyperfine interactions, the magnetic field generated by the vibrations of these oxygen nuclei orientates this central spin. To study specifically this spin-vibration interaction, the magnetic dipole contributions to the hyperfine structures observed in the ν 3 band of 189OsO 4 and 187OsO 4 have been analyzed in detail. Besides the spin-rotation constants already deduced in a previous paper, we have obtained the spin-vibration constant, A, and a small change of the spin-rotation constant δc a in the upper vibrational level. We have verified the speculated relation A= ζ 3 c a at the 1% level ( ζ 3 is the Coriolis coupling constant, which multiplies the internal vibrational angular momentum to turn it into a physical angular momentum comparable to the pure rotation angular momentum). Starting from first principles, we have rederived the expressions of the magnetic dipole constants for any semi-rigid polyatomic molecule. When these are applied to OsO 4, they justify the previous approximate relationship between A and c a and give values for the correction terms which account for the 1% difference. To cite this article: C. Chardonnet et al., C. R. Physique 5 (2004).

Forbidden transitions in a magneto-optical trap.

We report the first observation of a nondipole transition in an ultracold atomic vapor. We excite the 3P-4P electric quadrupole (E2) transition in 23Na confined in a magneto-optical trap, and we demonstrate its application to high-resolution spectroscopy by making the first measurement of the hyperfine structure of the 4P(1/2) level and extracting the magnetic dipole constant A=30.6+/-0.1 MHz. We use cw optical-optical double resonance accompanied by photoionization to probe the transition.

Hyperfine structure for neutral manganese lines of astrophysical interest

The hyperfine structure of 40 levels of neutral manganese has been studied by means of Fourier transform emission spectroscopy. The light source was a home-made 99.5% pure manganese hollow-cathode lamp. From the analysis of the line profiles observed in the visible and infrared regions, we have been able to deduce new magnetic dipole constants for 18 levels and to revise previous results for 22 additional levels.

Fine-structure analysis of the odd-parity Rydberg series of Zr I

A fine-structure (fs) analysis of the odd-parity Rydberg series of atomiczirconium, including the main low-lying mutually interacting configurations, hasbeen performed for the first time, with the aid of a linked-parameter method oflevel fitting. A set of derived fs parameters, together with ab initio valuescalculated for comparison, and the leading eigenvector percentages ofthe levels were obtained. Many of the levels belonging to the 4d25s5p, 4d5s25p and4d35pconfigurations are found to be incorrectly assigned. To confirm this majorrevision, specific mass shifts deduced from experimental isotope shiftdata available in the literature have been used as fingerprints. Finally, acomplete set of predicted magnetic dipole and electric quadrupole hyperfinestructure constants has been calculated for the known odd-parity levels inzirconium.

Hyperfine magnetic anomaly in the atomic spectra of rare-earth elements

Hyperfine-splitting constants in the optical spectra of rare-earth elements, Nd, Eu, Gd, and Lu, were measured using the laser-induced resonance fluorescence in a low-divergence atomic beam. Values of the hyperfine magnetic anomaly for different atomic levels were determined by comparing the ratios of the magnetic dipole constants of neighboring isotopes with odd numbers of protons or neutrons. The relation of these values to the special features of the atomic and nuclear structure of the investigated elements is discussed.

Hyperfine Structure of Neutral Vanadium Lines and Levels

We have recorded hollow-cathode spectra of neutral vanadium by Fourier transform spectroscopy in the near infrared – visible region (9000–17 000 cm-1). 36 transitions showing hyperfine structure have been analyzed, allowing us to deduce magnetic dipole constants for 27 levels belonging to the 3d44p and 3d34s4p configurations. For 22 of these levels no data were previously available.

Hyperfine Structure Measurements in the Lines 576.91 nm, 597.11 nm and 612.61 nm of La II

The hyperfine structure of the transition 5d6s b1D2 – 5d6p 3D1o (576.91 nm), 5d6s b1D2 – 5d6p x3F3o (597.11 nm) and 5d6s b1D2–5d6p x3F2o (612.61 nm) of 139La II has been measured by collinear laser-ion-beam spectroscopy. The magnetic-dipole constants A and electric-quadrupole constants B of the involved levels were determined.

Effects of electron correlation, relativity, and nuclear structure on hyperfine constants ofBe+andF6+

The hyperfine constants for the ground states of ${\mathrm{Be}}^{+}$ and ${\mathrm{F}}^{6+},$ and for the two lowest excited states of ${\mathrm{Be}}^{+},$ are calculated in a multiconfiguration Dirac-Fock model. Convergence of the calculated magnetic dipole constants is studied as the active set of orbitals is systematically increased. The final results are compared with experimental data and theoretical values obtained from other methods.

Transitions between Hund's coupling cases for the X 2Π state of NO

The submillimetre-wave spectra of 14N16O, 15N16O, and 14N18O in both the X 2Π1/2 and X 2Π3/2 states have been measured in the frequency region 773 GHz to 1.1 THz and assigned. Transitions involving J values between 6.5 and 10.5 have been recorded for the first time. The higher J values display an uncoupling of the electronic spin S and the angular momentum L from the rotor axis. The S-uncoupling leads to an intermediate coupling condition between Hund's case (a) and (b), whereas the L-uncoupling causes a coupling scheme intermediate between Hund's case (a) and (d). An improved set of molecular parameters has been obtained for these isotopic species, including magnetic dipole and electric quadrupole constants.

Hyperfine-structure intervals and isotope shifts in the3p44s4PJ→3p44p4DJ′fine-structure multiplet of atomic chlorine by diode laser spectroscopy

We have measured hyperfine-structure splittings and isotope shifts in the $4s{}^{4}{P}_{J}\ensuremath{\rightarrow}4p{}^{4}{D}_{{J}^{\ensuremath{'}}}$ multiplet in atomic chlorine using Doppler-free saturated absorption spectroscopy with an external cavity diode laser. Spectra of seven of the eight components of this multiplet, which have wavelengths between 798 and 859 nm, were obtained. Values for the magnetic dipole and electric quadrupole hyperfine-structure constants of the ${}^{4}{P}_{1/2\ensuremath{-}5/2}$ and ${}^{4}{D}_{1/2\ensuremath{-}7/2}$ states in both ${}^{35}\mathrm{Cl}$ and ${}^{37}\mathrm{Cl}$ were found, and the isotope shifts of the seven transitions studied were measured. The data were also analyzed in an attempt to extract values for magnetic octupole coupling constants for some of the levels investigated, but these were found to be zero at the level of the experimental uncertainty of our measurements.

Precise g-Factor Determination of4f136s6pExcited States in Tm I

By means of the atomic-beam laser spectroscopy, the Zeeman effects of the transitions 4 f 13 ( 2 F o )6 s 2 0 cm -1 → 4 f 13 ( 2 F o 7/2 )6 s 6 p ( 3 P o 0 ) 16742.237 cm -1 , 4 f 13 ( 2 F o 7/2 )6 s 6 p ( 3 P o 1 ) 17343.374 cm -1 in Tm I are systematically investigated by applying the magnetic field up to 250 gauss. From the analysis, the magnetic dipole constants A for the three levels have been determined to be -374.40(35), -737.53(45), -166.56(14) MHz, respectively. The precise g-factors of the upper levels have been determined to be 1.31954(16), 1.02154(10), respectively. The theoretical Zeeman splittings calculated using these values are found to reproduce experimental data well.

Term analysis and hyperfine structure in neutral vanadium

High resolution spectra of neutral vanadium excited in a hollow cathode discharge with helium, neon and argon as carrier gases have been recorded in the infrared region (1800-9000 cm−1) by Fourier transform spectroscopy. A detailed analysis of the spectra has allowed to determine some missing terms in the doublet, quartet and sextet systems of the configurations 3d5, 3d34s5p, 3d44s, 3d44s, and 3d45d of V I. Investigation of the hyperfine structure patterns has confirmed the identification of the transitions and has given rise to the determination of 67 new magnetic dipole constants.

Hyperfine structure of infrared Al II lines

High-resolution profiles of Al II lines recorded in the infrared region () by Fourier transform spectroscopy (FTS) show resolved or partially resolved hyperfine profiles. The analysis of 10 Al II transitions is presented here. An investigation of these structures has allowed the deduction of magnetic dipole constants and electric quadrupole constants for six levels which are relevant to astrophysical studies and to astrophysical databases. All the results presented are new.

Hyperfine structure and absolute frequency of the ^87Rb 5P_3/2 state

We have constructed two highly stable and reproducible (87)Rb D(2)-saturated-absorption spectrometers at 780 nm, using dither/third-harmonic lock-in detection and radio-frequency sideband techniques, respectively. We achieved +/-3-kHz reproducibility and agreement between these two independent systems. Heterodyne measurements of the hyperfine splittings of the 5P(3/2) state give its magnetic dipole (A) and electric quadrupole (B) hyperfine constants with a 10-fold reduction in uncertainty.

Hyperfine structure measurements in Kr II

The fast ion beam laser technique has been utilized to study the hyperfine structure in the transitions 4d4D7/2-5p4D72/0 at 6420 A and 4d4D7/2-5p4D52/0 at 6303 A in singly-charged krypton. The magnetic dipole and electric quadrupole hyperfine constants have been extracted for the upper levels of the transitions.

Large-scale multiconfiguration Dirac-Fock calculations of the hyperfine-structure constants of the 2s 2S1/2, 2p 2P1/2, and 2p 2P3/2 states of lithium.

The hyperfine constants for the ground and two lowest excited states of lithium are calculated in a multiconfiguration Dirac-Fock model. Convergence of the calculated magnetic dipole and electric quadrupole constants is studied as the active set of orbitals is systematically increased. The final results are compared with experimental data and theoretical values obtained from other methods. {copyright} {ital 1996 The American Physical Society.}

Hyperfine structure of infrared vanadium lines

High resolution profiles of neutral vanadium lines have been recorded in the infrared region (1800-9000 cm-1) by Fourier transform spectroscopy. 106 transitions showing resolved or partially resolved hyperfine profiles have been analysed. An investigation of these structures has allowed the deduction of magnetic dipole constants for 101 levels. For 69 levels the results obtained are new. The results of the present work have been compared with the few data previously published in the literature and they are generally in good agreement.

Hyperfine structure calculations for inner atomic levels

The results of Hartree-Fock-Dirac numerical calculations are given for the magnetic dipole and electric quadrupole hyperfine constants for the K and LI-III shells for all Z from Z=10-100. A comparison is made with results obtained with simple analytic formulae for the case of hydrogen-like ions with a simple screening and nuclear finite-size corrections taken into account. Formulae are given for the atomic inner-shell hyperfine structure in the form suitable to calculate the hyperfine shifts of atomic states, excited in different processes, such as electron capture or an internal conversion.

Hyperfine-structure studies of Nb II: Experimental and relativistic configuration-interaction results.

We report an experimental and theoretical study of the hyperfine structure (hfs) in various metastable states in $^{93}\mathrm{Nb}$ ii. Hyperfine structures of five levels in Nb ii have been measured using a combination of the laser-rf double resonance and laser-induced fluorescence methods in a collinear laser--ion-beam geometry. Theoretically, for J=2, a multireference calculation of energies and hfs based on a relativistic configuration-interaction methodology of the lowest ten levels in the (4d+5s${)}^{4}$ manifold is reported. The average energy error is 450 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$. Many of the hyperfine constants show large changes from the Dirac-Fock values and the magnetic dipole constant has a 4% accuracy for the one J=2 level measured. We have also identified all the core-valence and core-core effects that dominate the energy differences and hfs.

Hyperfine structure and isotope shift of the 3s-3p transitions of atomic oxygen

Using high-resolution saturation spectroscopy, by means of both double heterostructure and multiple quantum-well AlGaAs diode lasers, we investigate the isotope shifts and the hyperfine structure in the 3s-3p transitions of the triplet and quintet systems of atomic oxygen. From the analysis of the signals from17O we can deduce precise values for the hyperfine structure magnetic dipole constants. A theoretical analysis allows us to bring into evidence core polarization effects in the hyperfine structure. By heterodyning two frequency locked lasers, we perform a direct frequency measurement of the isotope effect on the3S1→3P1,2,0 transitions. From the comparison with similar accuracy data on the corresponding quintet transitions, an upper bound to the size of the nuclear volume effect is given, and precise values for the specific mass contributions are consequently obtained.