Isotope shifts and nuclear radius measurements for helium and lithium

It is now well established that accurate relative values of the rms nuclear charge radius for light atoms can be extracted from a comparison between high-precision theory and experiment for the isotope shift in atomic transition frequencies. Results are available for isotopes of helium and lithium. This paper reviews and updates the interpretation of earlier measurements for He-3 relative to He-4, and Li-6 relative to Li-7. New results are presented for the quantum electrodynamic recoil corrections. Recent measurements for the halo nucleus He-6, and the short-lived nuclei Li-8, and Li-9 are discussed. The derived nuclear charge radii of 2.054(14), 2.30(4), and 2.24(4) fm, respectively, are compared with the predictions of various nuclear structure models.