Precise spectroscopic experiments with light atoms can provide information about nuclear properties that are very difficult to obtain in electron scattering experiments. For example, relative nuclear radii of low-Z isotopes can be determined accurately from isotope shifts. Theory has attained sufficient accuracy to study exotic, short-lived halo nuclei by interpreting precise spectroscopic measurements. However, serious inconsistencies remain in the measured isotope shifts for the D1 and D2 lines of the stable isotopes (6Li and 7Li). The latest experiments, within the last decade, are in strong disagreement with each other and with theory. We report on the progress of a new experiment at NIST to measure these lithium D lines using an optical frequency comb. A preliminary result for the splitting isotope shift (SIS) is presented.
Citation: Canadian Journal of Physics
Pub Type: Journals
Lithium, laser spectroscopy, optical frequency comb, fine structure, hyperfine structure, isotope shift, nuclear properties