Nuclear properties by laser spectroscopy in beams and rings

Laser spectroscopy is discussed as a source of information about nuclear physics properties. The quantities measured in such an experiment are atomic physics properties, namely the isotope shift and the hyperfine structure of the optical fluorescence spectra in the visible wavelength band. Nuclear physics information describing properties of the ground state and isomeric states of a nucleus can be extracted from these data, namely nuclear magnetic dipole moments, nuclear electric quadrupole moments, nuclear spins and the changes of the mean square charge radii between isotopes. Some recent results are reported as examples. The method of collinear fast-atomic-beam spectroscopy using the isotopically pure beams of on-line mass-separators and a very similar technique which has been proposed to study the hyperfine structure of hydrogen-like ions in the storage ring for cooled ions, ESR, under construction at GSI, are discussed. (orig.)