Electric quadrupole and magnetic dipole transition probabilities within the ground configuration of F+ - art. no. 062508

The radiative lifetime of the 2s(2)2p(4) S-1(0) level in F+ has been measur ed by time-resolved observations of both strong (though electric-dipole for bidden) decay branches: the electric quadrupole (E2) transition (approximat e to 80% branch) to the 2s(2)2p(4) D-1(2) level and the magnetic dipole (M1 ) transition (approximate to 20% branch) to the 2s(2)2p(4) P-3(1) level. We observed the fluorescence associated with both transitions from a populati on of F+ ions circulating in a heavy-ion storage ring. Our result for the F + 2s(2)2p(4) S-1(0) level lifetime of 420+/-12 ms provides a benchmark for theory. Moreover, although the calculated lifetimes vary by more than 20%, the calculated branching fractions vary by less than 4% and 7% for the S-1( 0) --> D-1(2) E2 and S-1(0) --> P-3(1) M1 transitions, respectively. Using our measured lifetime and the calculated branching fractions, we report sem iempirical transition probabilities for the S-1(0) --> D-1(2) E2 and S-1(0) --> P-3(1) M1 transitions of 1.90 s(-1) +/- 7% and 0.50 s(-1) +/-9%, respe ctively.