Beam-foil measurements of lifetimes of energy levels belonging to Sn III and Sn IV

1987 ◽  
Vol 65 (1) ◽  
pp. 7-12 ◽  
Author(s):  
E. H. Pinnington ◽  
J. A. Kernahan ◽  
W. Ansbacher

Beam-foil intensity decay curves for transitions in the wavelength range 750–5250 Å are used to derive the lifetimes of the 6s1S, 5p1P, 6p1P, 5d1D, 6d1D, 5p21D, 4f1F, 6s3S, 6p3p, 5p23p, 5d3D, 6d3D, and 4f3F levels of Sn III, and of the 6s2S, 5p2P, 6p2P, 5d2D, 6d2D, 4d95 s22D, and 4f2F levels of Sn IV. The arbitrarily normalized decay-curve analyses are used for most levels. Good agreement is found between experiment and a recent (relativistic Hartree–Fock + core-polarization) calculation for the resonance transition in low-Z members of the Cd 1 isoelectronic sequence, but the experimental f values are found to lie systematically about 20% above the theoretical trend obtained from a similar calculation for the Ag I sequence. Configuration interaction is found to produce very different lifetimes for the two 4d95s22D levels of Sn IV, and the energy of the J = 3/2 level is determined to be 177 060 ± 50 cm−1.

1988 ◽  
Vol 66 (5) ◽  
pp. 402-404 ◽  
Author(s):  
W. Ansbacher ◽  
E. H. Pinnington ◽  
J. A. Kernahan

Beam-foil intensity decay curves for transitions in the wavelength range from 900 to 2200 Å are used to derive the lifetimes of the 6s6p1P1 and 3P1 6s6d1D2, 6s7s1S0, and 6p21D2 levels of Pb III, and the 6p2P1/2 and 2P3/2, 6d2D3/2 and 2D5/2, 7s2S1/2, and 5d96s22D3/2 levels of Pb IV, arbitrarily normalized decay curve (ANDC) analyses being used for the 6s6p and 6p levels. In the case of the two 6s6p levels studied in Pb III, good agreement is found with a recent calculation in which a polarization model accounts for valence–core correlation. However, the agreement between the lifetimes observed for the 6p levels in Pb IV and a similar, earlier calculation is only fair.


1986 ◽  
Vol 64 (10) ◽  
pp. 1365-1368 ◽  
Author(s):  
W. Ansbacher ◽  
E. H. Pinnington ◽  
J. A. Kernahan ◽  
R. N. Gosselin

Lifetime measurements obtained by the beam-foil method are given for 13 levels in In II and 12 levels in In III. Particular attention has been paid to cascade correction with the application of a new arbitrarily normalized decay curves (ANDC) program. The results are compared with theory, and good agreement is found with recent multiconfiguration relativistic Hartree–Fock (MCRHF) calculations for the In II resonance transition. The results for 2P and 2D levels in In III and 1D levels in In II indicate a need for further calculations.


Atoms ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 48
Author(s):  
M. Raineri ◽  
M. Gallardo ◽  
J. Reyna Almandos ◽  
A. G. Trigueiros ◽  
C. J. B. Pagan

A capillary pulsed-discharge and a theta-pinch were used to record Kr spectra in the region of 330–4800 Å. A set of 168 transitions of these spectra were classified for the first time. We extended the analysis to twenty-five new energy levels belonging to 3s23p24d, 3s23p25d even configurations. We calculated weighted transition probabilities (gA) for all of the experimentally observed lines and lifetimes for new energy levels using a relativistic Hartree–Fock method, including core-polarization effects.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Dhia Elhak Salhi ◽  
Soumaya Manai ◽  
Sirine Ben Nasr ◽  
Haikel Jelassi

Abstract Energy levels, wavelengths, weighted oscillator strengths, transition probabilities and lifetimes are calculated for all levels of 1s 2 and 1snl (n = 2–6) configurations of He-like cadmium ion (Cd XLVII). The calculations were carried out using three codes GRASP2018, FAC and AMBiT in order to provide theoretically the most accurate data. Transition probabilities are reported for all the E1, E2, M1 and M2 transitions. Breit interactions and quantum electrodynamics effects are included in the RCI calculations. Comparisons were made with other calculations and a good agreement was found which confirms the reliability of our results. We present some missing data for the He-like cadmium in this paper for the first time.


1967 ◽  
Vol 45 (5) ◽  
pp. 1661-1673 ◽  
Author(s):  
Maurice Cohen ◽  
Paul S. Kelly

Hartree–Fock wave functions for a number of S, P, and D states of the lithium isoelectronic sequence have been calculated, using a simplified procedure described in an earlier paper. Transition matrix elements for all permitted dipole transitions between these states have been computed using both the dipole length and the dipole velocity formulations. The results are in good agreement with earlier calculations.


2001 ◽  
Vol 79 (7) ◽  
pp. 999-1009 ◽  
Author(s):  
C Colón ◽  
A Alonso-Medina

Radiative transition probabilities for 190 lines arising from the ns 2S1/2, np 2P1/2,3/2, nd 2D3/2,5/2, nf 2F5/2,7/2, and 6p2 (4P1/2,3/2,5/2, 2D3/2,5/2, 2P1/2,3/2, and 2S1/2) levels of Pb(II) have been calculated. Lifetimes of the above mentioned levels have been determined from the present transition probabilities. These values were obtained in intermediate coupling (IC) and using ab initio relativistic Hartree-Fock calculations. For the IC calculations, we use the standard method of least-square fitting of experimental energy levels by means of computer codes from Cowan. The results of calculations for radiative transition probabilities and excited states lifetimes are presented and compared with the experimental results present in the literature and with other theoretical values. There is generally good agreement between our values and the experimental data available. Analysis of the interaction shows that the level 4P5/2 of the 6s6p2 configuration presents a large contribution to the 2D5/2 level of the 6s26d configuration. This result explains the good agreement between our result and the experimental values obtained to the observed as the 6s6p2 4P5/2 – 6s 25f2F7/2 dipole-forbidden transition. PACS Nos.: 32.70^*, 32.70Fw, 32.70Cs


1967 ◽  
Vol 45 (6) ◽  
pp. 2079-2090 ◽  
Author(s):  
Maurice Cohen ◽  
Paul S. Kelly

Orbital wave functions for a number of singlet and triplet S, P, and D states of the helium sequence through C+4 have been calculated using an approximation described earlier. The wave functions have been employed to calculate the oscillator strengths for all allowed dipole transitions between these states, using both the length and velocity forms of the transition matrix element. Our results are in good agreement with the most accurate values available.


Author(s):  
Miao Wu ◽  
Zhencen He

The spectral parameters (energy levels, wavelengths, transition probabilities, line strengths and oscillator strengths) of resonance lines for Ba VIII, La IX and Ce X have been performed using the multiconfiguration Dirac-Hartree-Fock method, the contributions of quantum electrodynamics and Breit interactions correction are taken into considered. The calculated results of energy levels and wavelengths are in good agreement with experimental values and other calculation. The number of energy levels and wavelengths considered is larger than that of any other experiment values and other calculations. The transition probabilities, line strengths and oscillator strengths are also calculated where no other theoretical results and experimental values are available.


1976 ◽  
Vol 54 (14) ◽  
pp. 1465-1481 ◽  
Author(s):  
Charlotte Froese Fischer

An accurate theoretical study of ionization potentials and f values in the sodium iso-electronic sequence has been performed using a frozen core, multi-configuration Hartree-Fock procedure.The Z-dependence of core-polarization and its effect on the transition integral are investigated. The initial increase in both these quantities as Z increases is explained in terms of a relative collapse in the size of the atom. Analytic expressions are derived for 3s–3p, 3s–4p, 3p–4s, and 4s–4p transition integrals.Core-polarization has reduced the f values for the 3s–3p transitions somewhat, but still leaves a discrepancy of up to 25% between theory and recent beam–foil results.


Atoms ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 108
Author(s):  
Jorge Reyna Almandos ◽  
Mónica Raineri ◽  
Cesar J. B. Pagan ◽  
Mario Gallardo

Three-times ionized xenon Xe IV spectrum in the 1070–6400 Å region was analyzed using a pulsed discharge light source. A set of 163 transitions was classified for the first time, and 36 new energy levels belonging to the 5s25p26d and 5s25p27s even configurations were determined. The relativistic Hartree–Fock method, including core-polarization effects, were used. In these calculations, the electrostatic parameters were optimized by a least-square procedure in order to improve the adjustment to experimental energy levels. We also present a calculation based on a relativistic multiconfigurational Dirac–Fock approach.


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