Energies and hyperfine splittings of the 7D levels of atomic francium - art. no. 052507

We report optical double-resonance spectroscopy to locate and study the 7D( 3/2) and 7D(5/2) levels of a sample of Fr-210 atoms confined and cooled in a magneto-optical trap. The upper state of the 7P(3/2) trapping transition serves as the resonant intermediate level to reach the 7D states. The energ y difference to the ground state is measured for the accessible levels. We measure the hyperfine splittings: Delta>(*) over bar * (7D(3/2,)F = 15/2 <- ---> 13/2) = 167 +/- 4 MHz, Delta>(*) over bar * (7D(5/2),F = 17/2 <----> 1 5/2) = - 117.5 +/- 2.5 MHz, and Delta>(*) over bar * (7D(5/2),F = 15/2 <--- -> 13/2) = - 121 +/- 4 MHZ. Extrapolating the energies of the inaccessible hyperfine levels from the hyperfine constants and assuming B(7D(3/2)) = 0, the center-of-gravity energy difference to the ground state is E(7D(3/2)) = 24 244.831 +/-0.003 cm(-1) and E(7D(5/2)) = 24 333.298+/-0.003 cm(-1).