Hyperfine structure of the 6dD3/22 level in trapped short-lived 211, 209Ra+ ions

The hyperfine structure of short-lived trapped 211,209Ra+ ions was investigated by means of laser spectroscopy. The hyperfine structure constants A and B   of the 6dD3/22 level were determined. There is a 2.2 standard deviation difference between the theoretical and the more accurate experimental value for the B coefficient of 211Ra+. These measurements provide a test for the atomic theory required for upcoming experiments on atomic parity violation and atomic clocks.

► The hyperfine structure of trapped 211, 209Ra+ was studied with laser spectroscopy. ► The hyperfine structure constants A and B   of the 6dD3/22 level were determined. ► A 2.2σ difference with theory is found for the B coefficient of 211Ra+. ► These measurements test atomic theory, needed in atomic parity violation experiments.