Model-potential calculation of lifetimes of Rydberg states of alkali atoms

Abstract

A comprehensive set of transition probabilities and radiative lifetimes of Rydberg states of alkali atoms (for Na, K, Cs, n 30; and for Rb, n 6 50) is obtained by using a simple, exactly solvable potential model for atoms. The results agree well with the available experimental values and other theoretical ones. Scaling relations for evaluating transition probabilities and lifetimes of high Rydberg states are also discussed. The well known (n*)-' scaling law of the transition probabilities A,,,,. with n'= n >> 1 is generally valid; however, we also find deviations from this law for some d-, p and f-* d transitions for Rb. A third-power polynomial is found to be better than the currently used exponential scaling law in predicting the lifetimes of even higher excited states.

Quasiclassical calculations of blackbody-radiation-induced depopulation rates and effective lifetimes of RydbergnS,nP, andnБетеров1, Ryabtsev2, Tretyakov3 et al. 2009Phys. Rev. A374122512View full textAdd to dashboardCite

“…1). On the other hand, we have checked that our quasiclassical model gives better agreement with the experiment and model-potential calculations [8,9], than the commonly used Coulomb approximation method [5]. For nP states, the disagreement between theory and the experiment is more significant, and we may conclude that more accurate experimental measurements would be of great interest.…”

“…The radiative lifetimes τ 0 of alkali-metal Rydberg states calculated by us are compared with the available theoretical data [8,9] in Table III and in Fig. 4 (for Na and Rb).…”

“…The Coulomb approximation method was applied by Farley and Wing [4] and Spencer et al [6] for numerical calculations and provided good agreement with experimental results. Theodosiou [8] and He et al [9] used a method of model potential with different atomic potential functions. A quasiclassical approximation is most suitable for states with large principal quantum numbers n > 20.…”

“…The temperature dependence of BBR-induced depopulation rate was measured experimentally for the sodium 19S state [7] and compared with numerical calculations. Theodosiou [8] performed the model-potential calculations of the effective lifetimes of alkali-metal Rydberg states with n≤21 for several ambient temperatures in the range from 0 to 720 K. Later on, model-potential calculations of radiative lifetimes for an extended range of n were done by He et al [9]. For most of alkali-metal Rydberg atoms, radiative lifetimes were calculated up to n=30, while for rubidium the calculations were done up to n=50.…”

“…For determination of effective lifetimes at 300 K and comparison with available experimental results, the authors of Ref. [9] used the data of Farley and Wing [4]. Galvez et al [10,11] investigated the cascade of BBR-induced transitions from the initially populated n=24-29 states of Na, both theoretically and experimentally.…”