Relativistic calculation of Kα hypersatellite line energies and transition probabilities for selected atoms with 12 ⩽Z⩽ 80

2006 ◽  
Vol 40 (1) ◽  
pp. 57-68 ◽  
Author(s):  
A M Costa ◽  
M C Martins ◽  
J P Santos ◽  
P Indelicato ◽  
F Parente
2013 ◽  
Vol 769 (1) ◽  
pp. 84 ◽  
Author(s):  
C. T. Chantler ◽  
T. V. B. Nguyen ◽  
J. A. Lowe ◽  
I. P. Grant

1971 ◽  
Vol 26 (3) ◽  
pp. 368-370 ◽  
Author(s):  
O.W.B. Schult

Abstract Experimental K-X-ray intensity ratios Kα2/Kα1, Kα3/Kα , Kβ1/Kα1 , Kβ2/Kβ1 , Kβ3/Kβ1 , Kβ4/Kβ1 and Kβ5/Kβ1 have been determined for several elements with 63≤Z≤92. These ratios agree very well with the results of a fully relativistic calculation of transition probabilities by Rosner and Bhalla. The theoretical values are tested with an accuracy of better than one per cent for the ratios Kα2/Kα1 , Kβ2/Kβ1 and Kβ3/Kβ1 .


2021 ◽  
pp. 126-133
Author(s):  
P. Zaichko ◽  
A. Kuznetsova ◽  
A. Tsudik ◽  
V. Mansarliysky

We present the results of relativistic calculation of the radiative transition probabilities and excited states lifetimes for a heavy Rydberg atomic systems in a black-body (thermal) radiation field on example of the rubidium. As theoretical approach we apply the combined generalized relativistic energy approach and relativistic many-body perturbation theory with ab initio Dirac zeroth  approximation. There are obtained the calculational data for the radiative transition probabilities and excited states lifetimes, in particular, the rubidium atom in the Rydberg states with principal quantum number n=10-100. It is carried out the comparison of obtained theoretical data on the effective lifetime for the group of Rydberg  nS states of the rubidium atom at a temperature of T = 300K with experimental data as well as data of alternative theoretical calculation based on the improved quasiclassical model.  It is shown that the  accuracy of the theoretical data on the radiative transition probabilities and excited states lifetimes is provided by a correctness of the corresponding relativistic wave functions and accounting for the exchange-correlation effects.


Author(s):  
C. C. Ahn ◽  
D. H. Pearson ◽  
P. Rez ◽  
B. Fultz

Previous experimental measurements of the total white line intensities from L2,3 energy loss spectra of 3d transition metals reported a linear dependence of the white line intensity on 3d occupancy. These results are inconsistent, however, with behavior inferred from relativistic one electron Dirac-Fock calculations, which show an initial increase followed by a decrease of total white line intensity across the 3d series. This inconsistency with experimental data is especially puzzling in light of work by Thole, et al., which successfully calculates x-ray absorption spectra of the lanthanide M4,5 white lines by employing a less rigorous Hartree-Fock calculation with relativistic corrections based on the work of Cowan. When restricted to transitions allowed by dipole selection rules, the calculated spectra of the lanthanide M4,5 white lines show a decreasing intensity as a function of Z that was consistent with the available experimental data.Here we report the results of Dirac-Fock calculations of the L2,3 white lines of the 3d and 4d elements, and compare the results to the experimental work of Pearson et al. In a previous study, similar calculations helped to account for the non-statistical behavior of L3/L2 ratios of the 3d metals. We assumed that all metals had a single 4s electron. Because these calculations provide absolute transition probabilities, to compare the calculated white line intensities to the experimental data, we normalized the calculated intensities to the intensity of the continuum above the L3 edges. The continuum intensity was obtained by Hartree-Slater calculations, and the normalization factor for the white line intensities was the integrated intensity in an energy window of fixed width and position above the L3 edge of each element.


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