[en] Thermal Ionisation Mass Spectrometry is an internationally recognised technique for determining the isotope ratio and concentrations of different elements including actinides with the highest precision and accuracy

No abstract available

[en] Short communication. 4 refs

No abstract available

[en] Full text: Exotic nuclei beyond the ¹³²Sn double-shell closure are influenced by both the Sn superfluidity and the evolving collectivity only few nucleons away. Toward even more neutron-rich nuclei, especially at intermediate mass number, interplay between single-particle and collective particle-hole excitations compete. In some cases with the extreme addition of neutrons also other effects as the formation of neutron skin [1], stabilization as sub-shell gaps [2], and/or orbital crossings [3] may be expected. The knowledge of nuclear ingredients is especially interesting beyond ¹³²Sn and little is known on how the excitations modes develop with the addition of both protons and neutrons [4-7] and for example systematic prompt and decay lifetime studies can be a very sensitive probe. Recently, we have approached this region of nuclei in several measurements following fission as ²³⁸U on ⁹Be target, within the EURICA project [8-9], n-induced fission on ²³⁵U/²⁴¹Pu targets using prompt-decay spectroscopy within the EXILL/FATIMA campaigns [10-11], as well as in decay spectroscopy at LOHENGRIN. Examples from these studies on several nuclei in the region will be presented together with the possible interpretation of the new data.

[en] The philosophy behind the experimental approach is described. A list of reports on completed work is given. Comments are offered on work on Au, Tl, and Hg isotopes, neutron-deficient nuclei with 50 less than or equal to (Z,N) less than or equal to 82, and neutron-rich nuclei with 28 less than or equal to Z less than or equal to 50 and 50 less than or equal to N less than or equal to 82. No data are presented, as this work has been reported at length in numerous reports and journal articles. Experimental equipment and procedures and data analysis are summarized briefly

[en] We study the role of intruder states and shape coexistence in the even-even "1"9"0"–"2"0"6Po isotopes, through an interacting boson model with configuration mixing calculation. We analyzed the results in the light of known systematics on various observable in the Pb region, paying special attention to the unperturbed energy systematics and quadrupole deformation. We find that shape coexistence in the Po isotopes behaves in very much the same way as in the Pt isotopes, i.e., it is somehow hidden, contrary to the situation in the Pb and the Hg isotopes

[en] The nuclear spin of ¹⁸⁵Au, I = 5/2, and the hyperfine separation of ¹⁸⁸Au, Δγ = +- 2992(30) MHz, have been measured with the atomic-beam magnetic resonance method. The spin of ¹⁸⁵Au indicates a deformed nuclear shape in the ground state. The small magnetic moment of ¹⁸⁸Au is close in value to those of the heavier I = 1 gold isotopes ^190192194Au, being located in a typical transition region. (Auth.)

[en] Fissile gram equivalent (FGE) or fissile equivalent mass (FEM) methodology is used to characterize isotope mixtures for criticality safety when configurations make exact modeling impractical. This paper reviews the FGE method using current cross sections (ENDF/B-VII.0) with the MCNP5 Monte Carlo code to determine whether the method gives conservative or nonconservative estimates of reactivity for mixed-isotope systems. To determine ²³⁹Pu equivalence factors (PEFs) this study uses isotopic critical masses for ²³⁹Pu, ²³³U, ²³⁵U, and ²⁴¹Pu calculated with MCNP5 using ENDF/B VII.0 cross sections to minimize effects of differences in k_eff for published subcritical limits. ²⁴⁰Pu was added as an example of a non-fissile isotope in FGE calculations. All moderated configurations used optimally-moderated homogeneous metal-water mixtures with a 30- cm thick water reflector. Configurations of mixed-isotope metal spheres with water reflectors are also included in the study. The results clearly show a conservative trend to moderated mixtures. Similar results are obtained for fissile isotopic metal mixtures and a combination of fissile and non-fissile isotopes. Results are shown to be conservative in all cases, justifying use of the FGE methodology for systems of mixed isotopes where exact geometries are not known. (authors)

No abstract available