Since 2000, six new super-heavy elements with atomic numbers 113 through 118 have been synthesized in hot fusion reactions of 48 Ca beams on actinide targets. These target materials, including 242 Pu, 244 Pu, 243 Am, 245 Cm, 248 Cm, 249 Cf, and 249 Bk, are available in very limited quantities and require specialized production and processing facilities resident in only a few research centers worldwide. This report describes the production and chemical processing of heavy actinide materials for super-heavy element research, current availabilities of these materials, and related target fabrication techniques. The impact of actinide materials in super-heavy element discovery is reviewed, and strategies for enhancing the production of rare actinides including 249 Bk, 251 Cf, and 254 Es are described.

The structures of Pu(IV) hydrous polymers were measured by small-angle neutron scattering (SANS) in aqueous media and after solvent extraction in organic phases. The scattering data from polymers occurring as aqueous colloidal suspensions indicate long, thin, rodlike particles. Pu(IV) hydrous polymers formed in the presence of uranium were shorter than those produced in the absence of uranium; this is consistent with earlier observations that uranium reduces the rate of Pu(IV) polymer formation. The Pu(IV) polymers were extracted into C6D6 solutions by alkyl esters of phosphoric acid. The extractant-Pu polymer geometries were shorter than those in the aqueous media; their radii were increased by the lengths of the extended alkyl substituents of the extractants. Comparable extractions of Pu(IV) monomers were also examined. X-ray scattering measurements exhibit well-defined Bragg diffraction lines for the Pu polymer in both the aqueous and organic phases. All of the lines could be identified with those of PuOz.Spectrophotometeric measurements monitored the polymeric nature of the aqueous and organic suspensions.

No abstract

No abstract

No abstract