Lifetimes of the 9s and 8p levels of atomic francium -: art. no. 042504

We use time-correlated single-photon counting techniques on a sample of Fr-210 atoms confined and cooled in a magneto-optical trap to measure the lifetimes of the 9S(1/2), 8P(3/2), and 8P(1/2) excited levels. We populate the 9S(1/2) level by two-photon resonant excitation through the 7P(1/2) level. The direct measurement of the 9S(1/2) decay through the 7P(3/2) level at 851 nm gives a lifetime of 107.53 +/- 0.90 ns. We observe the decay of the 9S(1/2) level through the 8P(3/2) level at 423 nm and the 8P(1/2) level at 433 nm down to the 7S(1/2) ground level, and indirectly determine the lifetimes of these to be 83.5 +/- 1.5 ns and 149.3 +/- 3.5 ns, respectively.