Hyperfine-InducednMixing in High Rydberg States ofSr87

Abstract
The hyperfine structure of high Rydberg states of Sr87 was studied for principal quantum numbers 80<~n<~150. The hyperfine interaction causes a strong singlet-triplet mixing between levels with the same total angular momenta F but different quantum numbers n. Semiempirical calculations show excellent agreement with experiment.