Hyperfine structure and isotope shift of the D2 line of /sup 76en-dash98/Rb and some of their isomers

Hyperfine structure, spin, and isotope shift measurements have been performed on /sup 76en-dash98/Rb and /sup 78,81,82,84,86,90/Rb/sup m/. The Rb nuclei have been produced either by spallation of Nb or by fission of U by a 600 MeV proton beam. They have been separated in mass before being transformed into a thermal atomic beam which interacts at a right angle with the light from a c.w. tunable dye laser. The charge radii changes deduced from the isotope shifts exhibit shell effects at N = 50 and deformations at N = 60, which are discussed