In bombardments of Cm with "Ne we discovered two new isotopes, ' '106 and '""106, by establishing genetic links between their u decays and spontaneous fussion (SF) or u decays of the daughter nuclides. We measured E = 8.63~0.05 MeV for ' 106 and a half-life of 1.2 s for its daughter 6'104. For ' '106 we measured E = 8.71 to 8.91 MeV. From these n energies we estimated n half-lives of 10 -3Q s for ' 106 and 2 -3Q s for ' '106. We estimated SF branches of 50% or less for both isotopes. The decay properties of ' '106 establish the existence of enhanced nuclear stability near the predicted deformed shells N = 162 and Z = 108.PACS numbers: 21.10. Tg, 23.60.+e, 25.70.Gh, 27.90.+b Recent macroscopic-microscopic calculations (see, e. g.,
Several new high-spin states are observed in the prompt ␥-rays emitted from the neutron-rich, odd-Z 145,147 La fragments produced in the spontaneous fission of 252 Cf. Alternating parity bands are extended up to spins 41/2 and 43/2 in 145,147 La, respectively. A new band completes the evidence for two sets of parity doublets expected for octupole correlations. Eight B(E1)/B(E2) ratios ͑four new͒ between two bands in 145 La are all essentially constant and somewhat larger than similar ratios in 143,144 Ba, where stable octupole deformation and/or correlations are reported. The new ratios out of the 31/2 Ϫ levels in both nuclei show a sharp spike compared to other states, presumably from a strong reduction in E2 strengths in this backbending region. In 145 La, collective bands show competition and coexistence between symmetric and asymmetric shapes. Band crossings occur in both nuclei around បϷ0.26-0.30 MeV. Their backbends are associated with the alignment of two i 13/2 neutrons according to cranked shell model calculations. ͓S0556-2813͑99͒08402-2͔ PACS number͑s͒: 21.10. Re, 23.20.Lv, 27.60.ϩj, 25.85.Ca
The recognition criterion for discovery of a new chemical element includes two aspects, the characterization properties and the assignment properties. In this paper, we will discuss the status of element 115 experiments that have been performed in Dubna, Russia, highlighting the characterization and assignment properties as they specifically relate to a recent experiment. After discussing the status of what is known about the decay properties of element 115 [1], observed previously using the Dubna Gas-Filled Recoil Separator, we will discuss the prior chemical studies that have been performed on the Db descendant of element 115 [2]. Following the success of that experiment, some additional chemical information was desired. Two separation chemistries were then developed at LLNL and JINR. LLNL utilized reversed phase chromatography and JINR utilized anion exchange chromotography to perform not only +4/+5 separations, but also intra-group separations, where Nb-like and Ta-like fractions were eluted. The results from an experiment using these chemistries for the first time during December 2005 in Dubna, Russia, will be compared with prior chemical results. We will conclude with a discussion of possible enhancements to the work already performed and the current status of the future experimental plans.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.