Electric Quadrupole Hyperfine Constants Research Articles

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.

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.

Studies on hyperfine structure and isotope shift of some excited states in Yb and Tm atoms

The hyperfine structures and isotope shifts in some excited states of Yb and Tm have been measured using laser-atomic beam interaction, stepwise excitation and fluorescence detection techniques. From the experimental results, magnetic dipole hyperfine constants A and electric quadrupole hyperfine constants B have been derived. So for as we know, the A factor of [4f125d6s6p]9/2 level in Tm is given for the first time.

A program for computing magnetic dipole and electric quadrupole hyperfine constants from MCHF wavefunctions

Given an electronic wave function, generated by the MCHF program ( LS format) or the MCHF_CI program ( LSJ format), this program computes the hyperfine interaction constants, A J and B J . In strong experimental magnetic fields, the splitting is also affected by the off-diagonal hyperfine constants A J,J-1 , B J,J-1 , and B J,J-2 and these are computed as well, depending on the input data.

Hyperfine structure of the A 3Π 1 state of IBr

We have recorded saturated absorption spectra of the A 3Π 1(ν=13)→ X 1Σ + (ν'=3) transition in 127I 79Br. The hyperfine structures of the Q(50) and Q(60) lines at 776.4 and 777.8 nm have been measured and fitted. The theoretical intensities of the hyperfine components have been calculated and synthetic spectra generated, in good agreement with the experimental ones. The magnetic dipole and electric quadrupole hyperfine constants in the upper state 3Π 1 (A') have been deduced: C I =544.5 (17.6) MHz, C Br =129.3 (14.4) MHz, eQq I=-1470.4 (4.4) MHz and eQq Br=570.1 (2.7) MHz.

Hyperfine structure of some excited states of 133Cs+ by collinear laser-ion beam spectroscopy.

Hyperfine structure of a few excited states of /sup 133/Cs/sup +/ in the 5/ital p//sup 5/5/ital d/ and 5/ital p//sup 5/6/ital p/ configurations has been measured by laser-induced fluorescence with a collinear laser and slow-ion-beam (/similar to/1.5 keV) apparatus. The hyperfine spectrum for the optical transition at 612.86 nm has been recorded for the first time. The full width at half maximum of the laser-induced fluorescence spectra recorded with our apparatus is typically 45--75 MHz. The magnetic dipole (/ital A/) and electric quadrupole (/ital B/) hyperfine constants have been determined for the two lower levels 5/ital p//sup 5/5d /sup 3/P/sub 2/, /sup 3/F/sub 4/ and the two upper levels 5/ital p//sup 5/6/ital p/ (3/2(3/2)/sub d/, 3)/2 (5/2)/sub 3/ at energies 112 803.99, 112 245.44, 129 998.63, and 129 116.56 cm/sup /minus/1/, respectively, above the ground state, 5/ital p//sup 6/ /sup 1/S/sub 0/.

Collinear laser and slow-ion-beam apparatus for high-precision laser-rf double-resonance spectroscopy

A new apparatus has been constructed for high-precision hyperfine structure measurement of atomic ions by laser-radio-frequency double-resonance technique involving a slow ion beam and a laser in collinear geometry. The low ion energy (1–1.5 keV) leads to longer interaction time with the applied rf field. Consequently, extremely narrow linewidths of ∼60 kHz have been observed for the first time in such systems. The apparatus has been used for the measurement of hyperfine structure of the 4f7(8S0)5d9D02,3,4,5 metastable levels in 151Eu+ and 153Eu+. The magnetic dipole and the electric quadrupole hyperfine constants, A and B, respectively, have been determined with higher precision (2–3 orders of magnitude).

Hyperfine structure of 4f126s and 4f125d Configurations in 167Er II Measured by Collinear Fast-Beam Laser and Radio-Frequency Laser Double-Resonance Spectroscopy

The collinear fast-beam-laser and rf-laser double-resonance technique has been used to make precise measurements of the magnetic dipole and electric quandrupole hyperfine constants of several states belonging to the 4f126s and 4f125d manifolds in 167Er II. The experimental data are analyzed within the Sandars-Beck effective-operator formalism by means of the parametric fitting approach, and a discussion of the results based on state-dependent ab initio multiconfiguration Dirac-Fock (MCDF) calculations of the magnetic dipole and electric quadrupole hyperfine constants is given. A 25% deviation between the experimental and ab initio MCDF values for the contact parameter ⟨r-3⟩6s10 is found, and possible causes of this discrepancy are discussed. In particular, the influence of the magnetic part of the Breit Hamiltonian on the reduced radial parameters of the Sandars-Beck theory has been investigated.

Observation of quantum beats in the 6D3/2-->5P1/2 transition in 85Rb.

Quantum beats due to the hyperfine interaction were observed in the 6${D}_{3/2}$\ensuremath{\rightarrow}5${P}_{1/2}$ transition in $^{85}\mathrm{Rb}$. Good agreement with theory was obtained, allowing determination of the values for the magnetic dipole (a=2.32\ifmmode\pm\else\textpm\fi{}0.06 MHz) and electric quadrupole (b=1.62\ifmmode\pm\else\textpm\fi{}0.06 MHz) hyperfine constants for the upper state.

Hyperfine structure in Tc I: experiment and theory

The low-lying multiplets were studied. HFS intervals have been measured in optical transitions by a photoelectric Fabry-Perot interferometer, and the values of the corresponding magnetic-dipole and electric-quadrupole hyperfine constants A and B have been deduced. Wavefunctions in intermediate coupling and configuration mixing have been determined for the odd levels (configurations 4d55s5p and 4d65p) and for the even levels (configurations (4d+5s)7). Using these wavefunctions, the HFS constants of the 4d, 5s and 5p electrons have been derived. An important result is a determination of the electric-quadrupole moment of 99Tc, Q=-0.19(5)b, without allowance for the Sternheimer correction.

Relativistic Hartree-Fock Hyperfine-Structure Calculations for the Scandium, Copper, Gallium, and Bromine Atoms

The magnetic dipole and electric quadrupole hyperfine constants have been calculated for the $^{2}D_{\frac{3}{2}}$ and $^{2}D_{\frac{5}{2}}$ states of scandium and copper and the $^{2}P_{\frac{1}{2}}$ and $^{2}P_{\frac{3}{2}}$ states of gallium and bromine atoms. Both restricted and unrestricted numerical relativistic Hartree-Fock calculations have been carried out; the relativistic core-polarization contribution to the hyperfine constants is studied in comparison with the nonrelativistic results.

Hyperfine-Structure Calculations for Atoms with the(4p)NGround-State Configuration

The magnetic dipole and electric quadrupole hyperfine constants have been calculated for the $^{2}P_{\frac{3}{2}}$ and $^{2}P_{\frac{1}{2}}$ states of gallium and bromine and the $^{3}P_{2}$ and $^{3}P_{1}$ states of germanium and selenium, using unrestricted and projected unrestricted Hartree-Fock wave functions to include the polarization of closed-shell effects, and relativistic Hartree-Fock-Slater wave functions to evaluate relativistic effects. The results indicate that both kinds of effects are important. The Land\'e factors ${g}_{J}$ have also been calculated (Breit-Margenau effect).