Trapping of Radioactive Atoms: the Legnaro Francium Magneto-Optical Trap

Experiments aimed at laser cooling and trapping of radioactive atoms Lire nowadays operational at several laboratories. They open up a bridge between atomic and nuclear physics. allowing new precise spectroscopic measurements and detailed analysis of nuclear decay processes. A magneto-optical trap (MOT) for francium atoms is almost operational at the INFN Legnaro laboratories; its characterization and optimization are under way. Measurements of francium production rate as a function of target temperature, primary beam intensity and energy have been carried out. Preliminary tests with other stable alkali atoms, aimed at an improvement of the MOT collection efficiency, are reported.