Resonance Ionization Spectroscopy of Rare-Earth Elements at Iris Facility

Abstract

The investigation of nuclei far from stability with the aid of atomic spectroscopy is a rather rapidly developing branch of nuclear physics. Information on the isotopic changes of ms charge radii, spins and electromagnetic moments of radioactive nuclei deduced from the experimental data on the isotope shifts (IS) and hyperfine structures (hfs) of optical lines gives us important new insight into nuclear structure. Different laser spectroscopy techniques have been applied for the IS and hfs measurements during the past decade. Among these methods resonance ionization spectroscopy (RIS) has proven to be one of the most efficient ones. By now,more than 100 ground and long lived isomeric states have been studied by RIS at IRIS mass-separator. Here we shall describe briefly our experimental set-up, with the emphasis on a new direction of further development of our installation, and present the latest experimental data for Gd, Tb and Eu isotopes as well as some theoretical considerations concerned with the interpretation of our previ-ous results ¹.