Separation of uranium isotopes by selective photoionization

Abstract

Considerable progress has been made during the past year in the development of selective photoionization processes for the separation of uranium isotopes~ Uranium enrichment by selective photoionization has been scaled from the microscopic level reported by Tuccio et al (I) in June 1974 to the milligram per hour rate ~2).' This progress has been supported by developments in the understanding of the uranium spec~ trum resulting from the application of tunable dye lasers as spectroscopic tools. In this paper, recent results of experiments on the laser photoseparation of uranium isotopes are reported. The high density of uranium energy levels in the I0,000 cm I to 50,000 cm I energy range provides the opportunity for selective photoionization of uranium by a number of d i f ferent schemes. Some of these are represented in Figure I. In Figure IA is shown a two-step process in which the isotopical ly selective step, h~l, is followed by the absorption of photons with energy h~ 2 to produce ions of the desired isotope. In the diagram, h~ 2 is shown terminating on an autoionization state or discrete state, above the ionization continuum of the atom to take advantage of the re lat ive ly large absorption cross section associated with these states. A B C D