Lifetime measurement of the metastable 4d 2D5/2 state in 88Sr+ using a single trapped ion -: art. no. 012509

The natural lifetime of the metastable 4d D-2(5/2) state in Sr-88(+) has been measured using a single laser-cooled, trapped ion. The ion was prepared in the 4d D-2(5/2) state by laser excitation of the 5s S-2(1/2)-4d D-2(5/2) quadrupole transition at 674 nm. The decay time was measured by using Dehmelt's electron shelving method to monitor the ion's electronic state. Two separate investigations were conducted under slightly different experimental conditions. 160 000 decay times from the 4d D-2(5/2) state were observed in total, and two different methods for determining the statistical value of the measured lifetime have been compared. Systematic effects have also been estimated, and including these effects yields a value of tau=390.8(1.6) ms (1 sigma uncertainty) for the natural lifetime.