arXiv:physics/0412073 · Physical Review A
Lifetime measurement of the 8s level in francium
E. Gómez, Luis A. Orozco, A. Pérez Galván, Gene D. Sprouse
Abstract
We measure the lifetime of the $8s$ level of $^{210}\mathrm{Fr}$ atoms on a magneto-optically trapped sample with time-correlated single-photon counting. The $7{P}_{1∕2}$ state serves as the resonant intermediate level for two-step excitation of the $8s$ level completed with a $1.3\text{\ensuremath{-}}\ensuremath{\mu}\mathrm{m}$ laser. Analysis of the fluorescence decay through the $7{P}_{3∕2}$ level gives $53.30\ifmmode\pm\else\textpm\fi{}0.44\phantom{\rule{0.3em}{0ex}}\mathrm{ns}$ for the $8s$ level lifetime.