Oscillator strengths and lifetimes for the S V spectrum

The semi-empirical weighted oscillator strengths (gf) and the lifetimes presented in this work for all experimentally known electric dipole S V spectral lines and energy levels were carried out in a multiconfiguration Hartree–Fock relativistic (HFR) approach. In this calculation, the electrostatic parameters were optimized by a least-squares procedure, in order to improve the adjustment to experimental energy levels. This method produces lifetime values and gf values that are in agreement with intensity observations used for the interpretation of spectrograms of solar and laboratory plasmas.     

Weighted oscillator strengths and lifetimes for the Si XII and Si XIII spectra

The weighted oscillator strengths (gf) and the lifetimes for Si XII and Si XIII presented in this work were carried out in a multiconfiguration Hartree-Fock relativistic (HFR) approach. In this calculation, the electrostatic parameters were optimized by a least-squares procedure, in order to improve the adjustment to experimental energy levels. This method produces gf-values that are in better agreement with intensity observations and lifetime values that are closer to the experimental ones. In this work we present all the experimentally known electric dipole Si XII and Si XIII spectral lines.     

Oscillator strengths and lifetimes of levels for ions of the rubidium isoelectronic sequence calculated by the Dirac-Fock method

The oscillator strengths f of the resonance transitions are calculated by the Dirac-Fock method for the first ten terms of the rubidium isoelectronic sequence. The variation of f values along the isoelectronic sequence is analyzed. The corresponding transition probabilities and lifetimes τ of the levels 5p ² P _1/2 and 5p ² P _3/2 are calculated. The dependence of τ on the ion charge is approximated by an analytical equation. The obtained values of f and τ are compared with experiment and other calculations.     

Oscillator strengths and lifetimes calculated by the Dirac-Fock method for the levels of ions of the cesium isoelectronic sequence

A new method of data transmission in DWDM systems along existing long-distance fiber-optic communication lines is proposed. The existing method, e.g., uses 32 wavelengths in the NRZ code with an average power of 16 conventional units (16 units and 16 zeros on the average) and transmission of 32 bits/cycle. In the new method, one of 124 wavelengths with a duration of one cycle each (at any time instant, no more than 16 obligatory different wavelengths) and capacity of 4 bits with an average power of 15 conventional units and rate of 64 bits/cycle is transmitted at every instant of a 1/16 cycle. The cross modulation and double Rayleigh scattering are significantly decreased owing to uniform distribution of power over time at different wavelengths. The time redundancy (forward error correction (FEC)) is about 7% and allows one to achieve a coding enhancement of about 6 dB by detecting and removing deletions and errors simultaneously.     

Line strengths and lifetimes for Kr II

Relative line strengths have been calculated for transitions between states of the 4p ⁴ 5p and 4p ⁴ 5s configurations in Kr II. The wavefunctions are obtained in intermediate coupling, including an effective correction for configuration interaction. Absolute values for the line strengths are determined using the coulomb approximation. Lifetimes for the upper 4p ⁴ 5p levels are given together with available experimental results for comparison.     

Line strengths and lifetimes for Kr II

Relative line strengths have been calculated for transitions between states of the 4p ⁴ 5p and 4p ⁴ 5s configurations in Kr II. The wavefunctions are obtained in intermediate coupling, including an effective correction for configuration interaction. Absolute values for the line strengths are determined using the coulomb approximation. Lifetimes for the upper 4p ⁴ 5p levels are given together with available experimental results for comparison.     

Weighted oscillator strengths and lifetimes for the Si II spectrum

The weighted oscillator strengths (gf) and the lifetimes for Si II presented in this work were carried out in a multiconfiguration Hartree–Fock relativistic (HFR) approach. In this calculation, the electrostatic parameters were optimized by a least-squares procedure, in order to improve the adjustment to experimental energy levels. This method produces gf-values that are in better agreement with intensity observations and lifetime values that are closer to the experimental ones. In this work we presented all the experimentally known electric dipole Si II spectral lines.     

Oscillator strengths for singly ionized oxygen

The electric dipole oscillator strengths for multiplet and individual lines between some doublet and quartet levels have been calculated using the weakest bound electron potential model theory (WBEPMT) in singly ionized oxygen. We employed both numerical Coulomb approximation (NCA) wave functions and numerical non-relativistic Hartree-Fock (NRHF) wave functions for expectation values of radii in determination of parameters. The calculated oscillator strengths have been compared with available theoretical and experimental results. A good agreement with results in literature has been obtained. Moreover, oscillator strengths not existing in the literature for some highly excited levels have been obtained using this method. Electronic supplementary material  Supplementary Online Material     

Weighted oscillator strengths and lifetimes for the S XIV spectrum

The weighted oscillator strengths gf and the lifetimes for S XIV presented in this work have been calculated in a multiconfigurational Hartree–Fock relativistic approach. In this calculation, the electrostatic parameters were optimized by a least-squares procedure in order to improve the adjustment to experimental energy levels. This method produces gf values that are in better agreement with observed line intensities and lifetime values closer to the experimentally determined ones. In this work we presented all the experimentally known electric dipole S XIV spectral lines. Published in Zhurnal Prikladnoi Spektroskopii, Vol. 76, No. 3, pp. 473–476, 2009.     

Xenon: Oscillator strengths and photoionization

Electron energy loss spectra of Xe have been analyzed by means of Fano and Lu's collision theory of spectra. A new and improved set of empirical parameters has been determined,eigenquantum defects, orthogonal transformation matrix, anddipole matrix elements. These data have been used to calculate the autoionized profile and the asymmetry parameterβ of the angular distribution of photoelectrons. The autoionization profile is in agreement with the measurements of Huffman, Tanaka, and Larrabee. In addition, the theory predicts a distinct interference effect betweens andd excitation. The energetic shifting between the measured and calculated asymmetry parameterβ observed previously is removed. Nevertheless, deviations concerning the magnitude ofβ nears state excitation are still left unexplained. They are probably due to insufficient resolution of the photoelectron measurement.     

Xenon: Oscillator strengths and photoionization

Electron energy loss spectra of Xe have been analyzed by means of Fano and Lu's collision theory of spectra. A new and improved set of empirical parameters has been determined,eigenquantum defects, orthogonal transformation matrix, anddipole matrix elements. These data have been used to calculate the autoionized profile and the asymmetry parameter of the angular distribution of photoelectrons. The autoionization profile is in agreement with the measurements of Huffman, Tanaka, and Larrabee. In addition, the theory predicts a distinct interference effect betweens andd excitation. The energetic shifting between the measured and calculated asymmetry parameter observed previously is removed. Nevertheless, deviations concerning the magnitude of nears state excitation are still left unexplained. They are probably due to insufficient resolution of the photoelectron measurement.     

Weighted oscillator strengths and lifetimes for the Si I spectrum

The weighted oscillator strengths (gf) and the lifetimes for Si I presented in this work were carried out in a multiconfiguration Hartree-Fock relativistic approach. In this calculation, the electrostatic parameters were optimized by a least-squares procedure, in order to improve the adjustment to experimental energy levels. This method produces gf-values that are in better agreement with intensity observations and lifetime values that are closer to the experimental ones. In this work we present all the experimentally known electric dipole Si I spectral lines.     

Oscillator strengths in the boron isoelectronic sequence

The quantum defect orbital formalism in both its relativistic and non-relativistic versions has been applied to the calculation of oscillator strengths in the sharp spectral series of some boron-like systems. The results are presented in both tabular and graphical forms.     

Oscillator strengths for O(II) ions

Oscillator strengths between various doublet states of O(II) ions are calculated with extensive use of multi-configuration wave functions. The lower levels for the transition are in the 2p^{3 2}D⁰ and 2p^{3 2}P⁰ states, and the upper levels are 2p⁴, 3s, and 3d states. The results, which are estimated to have errors of less than 10% for individual transitions, agree quite well with beam-foil experiments, as well as with calculations made by the use of the non-closed-shell many-electron theory (NCMET). The present ratios of transition probabilities are estimated to have errors of less than 20%. A comparison with recent branching ratio measurements indicates that agreement between theory and experiment is within the overlap of the error bars except for the $\text{538}\text{581}$ Å pair. Agreement with rocket measurements is only within the overlap of the error bars for the $\text{718}\text{797}$ Å pair.     

Oscillator strengths for collective excitations in molecular complexes

Collective excitations of exciton type are considered. The oscillator strength of a collective excitation is expressed in terms of the oscillator strengths of the one-electron transitions. The scope for negative absorption is discussed.     

Oscillator strengths for SiH and SiH deduced from the solar spectrum

Recent identifications of SiH (A²Δ-X²Π) and SiH⁺ (A¹Π-X¹Σ⁺) in the solar photospheric spectrum have enabled us to derive absolute oscillator strengths for the (0, 0) bands of these transitions: f₀₀(SiH) = 0.0033 and f₀₀(SiH⁺) = 0.0005. Our result for SiH is compared with other values.     

Oscillator strengths for the resonance transition in Fe15+

Summary We report Hartree-Fock and configuration-interaction calculations of both the length and velocity forms of the oscillator strengths for the resonance excitation 1s ²2s ² p ⁶3s ² S _J ^e →1s ²2s ²2p ⁵3s ^{2 2} P _J ⁰ , transition, which leads to autoionization (Auger transition), in the Fe¹⁵⁺ ion of the sodium isoelectronic sequence both inLS and intermediate coupling schemes. Comparison is made with available results. A part of this work was done while the author was Research Director and Professor, CNRS Laboratory, University of Paris-Sud, Paris and Observatoire de Paris, Meudon, Paris, France.     

Oscillator strengths of Cs and Rb-like ions

Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 56, No. 1, pp. 13–17, January, 1992.     

Transition probabilities, oscillator strengths and lifetimes for singly ionized magnesium

The electric dipole transition probabilities, oscillator strengths and lifetimes have been calculated using the weakest bound electron potential model theory (WBEPMT) for singly ionized magnesium. In the calculations both multiplet and fine structure transitions are studied. We have employed both the numerical Coulomb approximation (NCA) method and numerical non-relativistic Hartree-Fock (NRHF) wave functions for expectation values of radii. The calculated oscillator strengths and lifetimes have been compared with MCHF results given by Fischer et al. (2006). A good agreement has been obtained with the MCHF results. Moreover, some new transition probabilities, oscillator strengths and lifetime values, not existing in the data bases for highly excited levels in singly ionized magnesium, have been obtained using this method.