RESONANT IONIZATION SPECTROSCOPY OF BA- - METASTABLE AND STABLE IONS

A new technique based on the combination of laser photodetachment and resonance ionization spectroscopy has been used to characterize the st ate composition of a fast, negative-ion beam of barium and to determin e the binding energies of its long-lived components, the metastable 5d 6s6p F-4(9/2) state and the 6s(2)6p P-2(3/2,1/2) ground state, with an accuracy previously inaccessible for the weakly bound, negative alkal ine-earth ions. Additional information about the Ba- states was obtain ed from lifetime studies in the ASTRID storage ring.