Feasibility study of in-beam polarization of fluorine

The feasibility of in-beam polarization of nuclear spin in F+ beams was studied. It was demonstrated that metastable atomic fluorine could be optically pumped on the closed transition (3s 4P5/2→3p 4D7/2) at 686 nm. The metastable production efficiency in sodium vapor was measured using optical depopulation pumping of the metastable on the (3s 4P5/2→3p 4D5/2) transition at 678 nm. At low helium density, 0.24 (+0.16/−0.03) of the reionized beam was derived from metastables, implying an ion beam polarization of 24% would be feasible if the metastables were fully polarized. The hyperfine structures of the 3s 4P5/2, 3p 4D5/2 and 3p 4D7/2 states in 19F were measured via laser-induced fluorescence and modulated optical depopulation pumping. Based on these results, a scheme is suggested for polarizing 20F.