Formula for determining the radiative lifetime τ of excited levels of the hydrogen atom

V. N. Gorshkov, V. A. Komarovskii, N. P. Penkin

Pavel Bogdanovich, G. L. Zhukauskas, Alina Momkauskaitė

Nikolai N. Bezuglov, Evgenii N. Borisov, Ya. F. Verolainen

The empirical regularities in the variation of the radiative lifetimes τ k of excited states of atoms are reviewed. A quasiclassical theory of radiation damping processes is constructed. The formalism of quantization of the natural width A k = τ k −1 of the excited states of atoms and ions is presented. The question of how to describe the serial dependences for a perturbed series is investigated. It is demonstrated that the radiation emission of atomic systems is sharply reduced when the classical factors in the radiative processes are suppressed. Schemes are proposed for extrapolating lifetimes from the lower terms of a series to the upper Rydberg states, right up to the continuum. Recommended values of τ k for group I, II, and VIII atoms are given in a form that is convenient for inclusion in a computerized data base.

H. Wang, J. Li, X. T. Wang +3 more

Rovibrational levels (v=0--30) of the ${0}_{\mathrm{g}}^{\mathrm{\ensuremath{-}}}$ ``pure long-range'' state of $^{39}\mathrm{K}_{2}$ are observed by photoassociative spectroscopy of ultracold potassium atoms prepared in a high-density magneto-optical trap. The measured molecular binding energies are used to precisely determine the long-range dipole-dipole potential constant ${\mathrm{C}}_{3}^{\mathrm{\ensuremath{\Pi}}}$ of the K(4s)+K(4p) asymptote and the radiative lifetime of the 4p state. We determine ${\mathrm{C}}_{3}^{\mathrm{\ensuremath{\Pi}}}$=-5.456(9) zJ ${\mathrm{nm}}^{3}$ (-8.445(14) a.u.), \ensuremath{\tau}(4${\mathrm{}}^{2}$${\mathrm{P}}_{3\mathrm{/}2}$)=26.34(5) ns, and \ensuremath{\tau}(4${\mathrm{}}^{2}$${\mathrm{P}}_{1\mathrm{/}2}$)=26.69(5) ns. Our result is a significant improvement in precision over previous lifetime measurements and agrees well with the recent fast-beam experiment [U. Volz and H. Schmoranzer, Phys. Scr. T65, 48 (1996)].

N. V. Afanaseva, P. F. Gruzdev

Chengfei Wang, Zhankui Jiang, Zhou Dafan +1 more

The natural radiative lifetime of some low-lying excited levels in Tm atoms have been determined from measurements of time-resolved laser-induced fluorescence in atomic beam. The levels were selectively populated by the light from a pulsed tunable dye laser pumped by an excimer laser or a Nd:YAG laser.