1 Introduction
Accurate radiative decay widths and probabilities, oscillator strengths of radiative
transitions in spectra of the Rydberg atomic systems (atoms in the highly excited
states with large values of the principal quantum number n ≫ 1) are of a great
interest for astrophysical analysis, laboratory, thermonuclear plasma diagnostics,
fusion research etc. (see, for example [1–60]). In recent years intensive theoretical
and experimental investigations of spectroscopic properties of the Rydberg atoms
are also stimulated by a great number of their possible important applications in
atomic and molecular optics and spectroscopy, quantum electronics, laser physics
(for example, speech is about new lasing schemes in the short-wave range with
using the Rydberg systems), quantum informatics and computing, astrophysics etc.
It is well known that the Rydberg atoms make the contribution into interstellar
clouds absorption spectrum (Rydberg states with n ∼ 300–700). The unique
properties of the Rydberg atoms are associated with too small ionization potentials,
sufficiently large size, enough long lifetime compared to conventional atomic states,
finally, unprecedented sensitivity to external fields. Really, it is well known that the
Rydberg atomic systems are very sensitive to electromagnetic fields and can be
used for the detection and sensing static and AC electric and magnetic fields.
Strongly interacting Rydberg systems have unique photon emission properties.
These facts stimulate more intensive research of the Rydberg atoms, in particular,
on the basis of new experimental methods of laser spectroscopy, beam-foil spectroscopy, using magneto-optical traps, synchrotron radiation sources, cryogenic
devices and so on. It is worth to remind about such unique and interesting physical
objects and phenomena such as the Rydberg matter, Bose-condensate in vapors of
the Rydberg alkali-metal atoms, fountains of cold Rydberg atoms etc.
The well-known quasiclassical and quantum-mechanical approaches such as the
Hartree-Fock (HF) and Dirac-Fock (DF) methods, quantum defect and the Coulomb
approximations, the model potential and pseudopotential methods etc. have been
used to calculate the spectroscopic properties of different light and middle Rydberg
atoms. In a case of the heavy Rydberg atoms in a free state or in an external
electromagnetic field a modern level of description of the Rydberg atoms is not
sufficiently satisfactory. A precise accounting for the relativistic and
exchange-correlation (XC) effects, including an effect of the non-Coulomb
grouping levels in the Rydberg spectra (the effect, which, as a rule, is not considered within simplified Coulomb and quantum defect models) is of a great interest
and importance.
The purpose of this work is to present the results of studying the radiation decay
processes and computing probabilities and oscillator strengths of the radiative
transitions in the spectra of heavy Rydberg atoms of alkali-metal elements. The
precise data on spectroscopic parameters (energies, reduced dipole transition matrix
elements, amplitude transitions) of the radiative transitions nS 1/2 → n′P 1/2,3/2 (n = 5,
6; n′ = 10–70), nP 1/2,3.2 → n′D 3/2,5/2 (n = 5, 6; n′ = 10–80) in the Rydberg Rb, Cs
spectra and the transitions 7S 1/2 -nP 1/2,3/2 , 7P 1/2,3.2 -nD 3/2,5/2 (n = 20–80) in the
230
V. B. Ternovsky et al.
Accurate radiative decay widths and probabilities, oscillator strengths of radiative
transitions in spectra of the Rydberg atomic systems (atoms in the highly excited
states with large values of the principal quantum number n ≫ 1) are of a great
interest for astrophysical analysis, laboratory, thermonuclear plasma diagnostics,
fusion research etc. (see, for example [1–60]). In recent years intensive theoretical
and experimental investigations of spectroscopic properties of the Rydberg atoms
are also stimulated by a great number of their possible important applications in
atomic and molecular optics and spectroscopy, quantum electronics, laser physics
(for example, speech is about new lasing schemes in the short-wave range with
using the Rydberg systems), quantum informatics and computing, astrophysics etc.
It is well known that the Rydberg atoms make the contribution into interstellar
clouds absorption spectrum (Rydberg states with n ∼ 300–700). The unique
properties of the Rydberg atoms are associated with too small ionization potentials,
sufficiently large size, enough long lifetime compared to conventional atomic states,
finally, unprecedented sensitivity to external fields. Really, it is well known that the
Rydberg atomic systems are very sensitive to electromagnetic fields and can be
used for the detection and sensing static and AC electric and magnetic fields.
Strongly interacting Rydberg systems have unique photon emission properties.
These facts stimulate more intensive research of the Rydberg atoms, in particular,
on the basis of new experimental methods of laser spectroscopy, beam-foil spectroscopy, using magneto-optical traps, synchrotron radiation sources, cryogenic
devices and so on. It is worth to remind about such unique and interesting physical
objects and phenomena such as the Rydberg matter, Bose-condensate in vapors of
the Rydberg alkali-metal atoms, fountains of cold Rydberg atoms etc.
The well-known quasiclassical and quantum-mechanical approaches such as the
Hartree-Fock (HF) and Dirac-Fock (DF) methods, quantum defect and the Coulomb
approximations, the model potential and pseudopotential methods etc. have been
used to calculate the spectroscopic properties of different light and middle Rydberg
atoms. In a case of the heavy Rydberg atoms in a free state or in an external
electromagnetic field a modern level of description of the Rydberg atoms is not
sufficiently satisfactory. A precise accounting for the relativistic and
exchange-correlation (XC) effects, including an effect of the non-Coulomb
grouping levels in the Rydberg spectra (the effect, which, as a rule, is not considered within simplified Coulomb and quantum defect models) is of a great interest
and importance.
The purpose of this work is to present the results of studying the radiation decay
processes and computing probabilities and oscillator strengths of the radiative
transitions in the spectra of heavy Rydberg atoms of alkali-metal elements. The
precise data on spectroscopic parameters (energies, reduced dipole transition matrix
elements, amplitude transitions) of the radiative transitions nS 1/2 → n′P 1/2,3/2 (n = 5,
6; n′ = 10–70), nP 1/2,3.2 → n′D 3/2,5/2 (n = 5, 6; n′ = 10–80) in the Rydberg Rb, Cs
spectra and the transitions 7S 1/2 -nP 1/2,3/2 , 7P 1/2,3.2 -nD 3/2,5/2 (n = 20–80) in the
230
V. B. Ternovsky et al.