RADIATIVE LIFETIMES, ABSORPTION CROSS-SECTIONS, AND OBSERVATION OF NEW HIGH-LYING ODD LEVELS OF U-238 USING MULTISTEP LASER PHOTOIONIZATION

Over 100 new high-lying odd levels are observed in atomic uranium between 32 600 and 34 200 cm** minus **1 using tunable laser techniques. These augment the 32 odd levels previously determined in this range by conventional atomic spectroscopy. The method used, multistep photoionization under pulsed dye laser excitation, was also used to make J assignments, measure radiative lifetimes, and to obtain absorption cross sections of transitions involving these levels.