Oscillator Strengths For Electric Dipole Transitions Research Articles

Semi-empirical analysis of the fine structure and oscillator strengths for atomic strontium

As the result of our studies on the atomic structure of complex atoms we produced high quality wave functions for both even and odd systems of configurations of Sr I. These wave functions were used for the parametrization of the oscillator strengths for electric-dipole transitions, where reliable data were available. The angular coefficients of the transition matrix in pure SL coupling were calculated by means of straightforward Racah algebra. The transition matrix was transformed into the actual intermediate coupling by the fine structure wave functions. The transition integrals were treated as free parameters in the least squares fit to the gf values. This procedure allowed us to obtain the values of the transition integrals and predict the values of oscillator strengths for the transitions from odd levels in a wide spectral range.

Properties of the Energy Bands, Judd-Ofelt Parameters and the Fluorescence of Neodymium Chloride (NdCl3) in Methanol, Iso-propanol and Butanol Solvents.

Absorption bands of neodymium chloride (NdCl3) dissolved in methanol, iso-propanol and butanol organic solvents at room temperature have been recorded in the ultraviolet-visible and near infrared regions between 190 and 1100nm. Adopting a free-ion Hamiltonian we have calculated and assigned the energy multiplets of the 4f (3) electronic configuration of the Nd(3+) ion, and thereby the best-fit parameters are estimated. We have measured the oscillator strengths of the observed absorptions and using the experimentally measured oscillator strengths the three Judd-Ofelt intensity parameters Ω2, Ω4 and Ω6 have been derived. Hence we have calculated the line strengths and the oscillator strengths for electric-dipole transitions. An intense fluorescence emission is found for (4)F3/2 → (4)I9/2 transition at 873nm, upon excitation with 581nm. The fluorescence characteristics are also investigated by evaluating the spontaneous transition probability (A), luminescence branching ratio (β), radiative lifetime (τ) and the stimulated emission cross section (σ).

Semi-empirical analysis of oscillator strengths for Nb II

Semi-empirical wave functions, proven via comparison of the expected and experimental hyperfine structure constants and gJ-factors in previous papers, were used for the parametrization of the oscillator strengths for electric-dipole transitions in Nb II, where reliable experimental data were available. The angular coefficients of the transition matrix in pure SL coupling were found from straightforward Racah algebra. The transition matrix was transformed into the actual intermediate coupling by the fine structure wave functions. The transition integrals were treated as free parameters in the least squares fit to experimental gf values. This procedure allowed us to obtain the values of transition integrals and predict the values of oscillator strengths for transitions from odd levels in a wide spectral range.

Relativistic effects in E1 transition oscillator strengths along the Yb+ isoelectronic sequence

Electric dipole transition oscillator strengths have been computed for low-lying transitions in the Yb+ isoelectronic sequence (through Ra19 +) in fully relativistic and non-relativistic-limit approximations. Relativistic effects were carefully investigated and efforts were undertaken to establish systematic trends in relativistic contributions to oscillator strengths along the Yb+ isoelectronic sequence.

DIRAC–FOCK OSCILLATOR STRENGTHS FOR E1 TRANSITIONS IN THE SODIUM ISOELECTRONIC SEQUENCE (Na I–Ca X)

Electric dipole transition oscillator strengths have been computed for low-lying transitions in the sodium isoelectronic sequence (Na I through Ca X) as well as for principal series in neutral sodium up ton= 24. The single-configuration Dirac–Fock method has been used. The core–valence electron correlation has been treated within the core polarization model and its importance to oscillator strength calculations is carefully studied.

Oscillator strengths for transitions among the low-lying fine-structure levels of chlorine

We have performed a large-scale configuration interaction calculation of the energies and wavefunctions of many low-lying fine-structure states of neutral atomic chlorine. Accurate oscillator strengths for electric-dipole transitions between these states are reported.