Spectroscopy of Radiative Decay Processes in Atomic Systems in a Black-Body Radiation Field

The effective relativistic approach to study of the energy, spectroscopic, radiation decay (excitation, ionization) characteristics of the Rydberg atomic systemsRydberg atomic systems in a Black-body radiation fieldBlack-body radiation field is presented and applied to computing the spectral parameters (effective lifetimes, transition probabilities) for a whole group of different nS, nP, nD states (n = 25–50) in the rubidium atom spectra, including highly excited states, at the temperature of 300 K. The approach is based on an advanced relativistic energy approachRelativistic energy approach (in a single-electron approximation realization) and the relativistic many-body perturbation theory with the Dirac–Kohn–Sham zeroth approximation. The key features of the approach are connected with the correct accounting for the exchange–correlation effects (the core polarization and screening effects, continuum pressure, non-Coulomb grouping of levels in Rydberg spectra, etc.), using optimized basis of relativistic wave functions and, respectively, fulfilling the principle of gauge invariance in calculation of the radiative decay matrix elements. The obtained spectroscopic data are compared with available experimental and alternative theoretical results.