scholarly journals RELATIVISTIC CALCULATION OF THE RADIATIVE TRANSITION PROBABILITIES AND LIFETIMES OF EXCITED STATES FOR THE RUBIDIUM ATOM IN A BLACK-BODY RADIATION FIELD

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.

2011 ◽  
Vol 89 (6) ◽  
pp. 697-702 ◽  
Author(s):  
Lin Zhuo ◽  
Bing-Cong Gou ◽  
Feng Wang

Energies and Auger widths of high-lying doubly-excited states 1s23lnl′ (n = 3–6) for Be-like neon are calculated using a saddle-point variational method and saddle-point complex-rotation method. The relativistic corrections and mass polarization are obtained with first-order perturbation theory. The configuration structure of the high-lying doubly-excited series is checked by relativistic perturbation corrections. The oscillator strengths and radiative transition probabilities are also calculated. Our results of energies and Auger widths are compared with the available theoretical results in the literature. Auger channel energies are compared with those from high-resolution electron spectroscopy. Excellent agreement is obtained in each state.


2014 ◽  
Vol 875-877 ◽  
pp. 23-27
Author(s):  
Ru Zhen Xing ◽  
Bing Chu Mei ◽  
Jing Hong Song ◽  
Xiao Nv Li

In this paper, we evaluated the spectra parameters of Er3+.The absorption spectra of Er3+:CaF2transparent ceramic was measured at room temperature (RT). Based on the Judd–Ofelt theory, the intensity parameters were Ω2= 5.02×10−20cm2, Ω4= 3.40×10−20cm2and Ω6= 0.38×10−20cm2, and then the values of the radiative transition probabilities, radiative lifetimes and integrated emission cross-sections of excited states were calculated. Full width at half maximum (FWHM) of the fluorescence spectra for4I13/2→4I15/2transition was investigated, being 17nm. The decay time was found to be 24.3ms, which is longer than the theoretically calculated value indicating a radiation trapping effect in this work.


2021 ◽  
pp. 118-125
Author(s):  
V. Ternovsky ◽  
A. Svinarenko ◽  
Yu. Dubrovskaya

Theoretical studying spectrum of the excited states for the ytterbium atom is carried out within the relativistic many-body perturbation theory with ab initio zeroth approximation and generalized relativistic energy approach.  The zeroth approximation of the relativistic perturbation theory is provided by the optimized Dirac-Kohn-Sham ones. Optimization has been fulfilled by means of introduction of the parameter to the Kohn-Sham exchange potentials and further minimization of the gauge-non-invariant contributions into radiation width of atomic levels with using relativistic orbital set, generated by the corresponding zeroth approximation Hamiltonian. The obtained theoretical data on energies E and widths W of the ytterbium excited states are compared with alternative theoretical results (the Dirac-Fock, relativistic Hartree-Fock, perturbation  theories) and available experimental data. Analysis shows that the theoretical and experimental values ​​of energies are in good agreement with each other, however, the values ​​of widths differ significantly. In our opinion, this fact is explained by insufficiently accurate estimates of the radial integrals, the use of unoptimized bases, and some other approximations of the calculation.


The technique described in part I has been used to obtain constants of interest in molecular spectroscopy. The vibration-rotation interaction factor, F for HCl has been evaluated from the infra-red emission spectrum. The critical parameter in F is θ = M 0 / M 1 r e , where M 0 and M 1 are the first two coefficients in the electric dipole moment expansion about the equilibrium internuclear distance r e . A value of θ = + 1.12 ± 0.18 has been obtained. It is shown that for molecules with θ = +1 the total band intensity in emission is independent of the rotational distribution in the vibrational state from which the emission occurs. This has been made use of in evaluating radiative transition probabilities. For the HCl v (3-1) transition a value for | R 3 1 | 2 (= 1.60 x 10 -4 debye 2 ) was obtained for the first time. The same method yields a value of | R 2 1 | 2 / | R 2 0 | 2 = 204, in good agreement with an earlier estimate from absorption data.


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