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Background: One-phonon mixed-symmetry quadrupole excitations are a well-known feature of near-spherical, vibrational nuclei. Their interpretation as a fundamental building block of vibrational structures is supported by the identification of multiphonon states resulting from a coupling of fully-symmetric and mixed-symmetric quadrupole phonons. In addition, the observation of strong M1 transitions between low-lying 3- and 4+ states has been interpreted as an evidence for one-phonon mixed-symmetry excitations of octupole and hexadecapole character. Purpose: The aim of the present study is to identify collective one- and two-phonon excitations in the heaviest stable N = 52 isotone 96Ru based on a measurement of absolute Ail, E1, and E2 transition strengths. Methods: Inelastic proton-scattering experiments have been performed at the Wright Nuclear Structure Laboratory (WNSL), Yale University, and the Institute for Nuclear Physics (IKP), University of Cologne. From the acquired proton-γ and γγ coincidence data we deduced spins of excited states, y-decay branching ratios, and multipole mixing ratios, as well as lifetimes of excited states via the Doppler-shift attenuation method (DSAM). Results: Based on the new experimental data on absolute transition strengths, we identified the 2+ and 3+ members of the two-phonon mixed-symmetry quintuplet (21ms+⊙21ms+).Furthermore, we observed strong M1 transitions between low-lying 3- and 4+ states suggesting one-phonon symmetric and mixed-symmetric octupole and hexadecapole components in their wave functions, respectively. The experimental results are compared to sdg-IBM-2 and shell-model calculations. Conclusions: Both the sdg-IBM-2 and the shell-model calculations are able to describe key features of mixed-symmetry excitations of 96Ru. Moreover, they support the one-phonon mixed-symmetry hexadecapole assignment of the experimental 42+ state. [ABSTRACT FROM AUTHOR]

New positive-parity states, having a bandlike structure, were observed in 105Ru. The nucleus was produced in an induced fission reaction, and the prompt γ-rays, emitted from the fragments, were detected by the EUROBALL III multidetector array. The partial scheme of excited 105Ru levels is analyzed within the triaxial-rotor-plus-particle approach. [ABSTRACT FROM AUTHOR]

Linear polarization and angular correlations of γ-rays depopulating excited states in the neutron-deficient nucleus 9444Ru50 have been measured, enabling firm spin-parity assignments for several excited states in this nucleus. The deduced multipolarities of strong transitions in the yrast structure were found to be mostly of stretched M1, E1, and E2 types and, in most cases, in agreement with previous tentative assignments. The deduced multipolarity of the 1869 keV and the connecting 257 and 1641 keV transitions indicates that the state at 6358 keV excitation energy has spin parity 12-1 rather than 12+3 as proposed in previous works. The presence of a 12-1 state is interpreted within the framework of large-scale shell-model calculations as a pure proton-hole state dominated by the π(p-11/2⊗g-59/2) and π(p-13/2⊗g-59/2) configurations. A new positive-parity state is observed at 6103 keV and is tentatively assigned as 12+2. The 14-1 state proposed earlier is reassigned as 13-4 and is interpreted as being dominated by neutron particle-hole core excitations. The strengths of several E1 transitions have been measured and are found to provide a signature of core-excited configurations. [ABSTRACT FROM AUTHOR]

Abstract: We report on the results of studies of the 95Tc isotope production conditions in a poorly investigated 96Ru(γ,N)95Tc reaction at a relatively inexpensive electron accelerator. Based on the analytical model it is demonstrated the possibility for estimating the effective and peak cross-sections and the isotope yield for a given reaction in a thick production target without preliminary determination of its excitation function. For this purpose we compared specific activities of two small samples that were activated under the same conditions using the reference reaction 68Zn(γ,p)67Cu and the one under investigation. The experiment on simultaneous photo-activation of natural zinc and ruthenium targets was performed followed by the investigation of their isotope composition. The specific activity of the radionuclide was measured and cross-sections for the 96Ru(γ,N)95g,mTc reactions were determined. The yields of desired isomers and admixtures in the natural ruthenium targets of different size were estimated. It is shown, in particular, that the operating conditions of the NSC KIPT accelerator KUT-30 can provide 95gTc yields up to 120mCi/h. [Copyright &y& Elsevier]

Abstract: A sample of 100MoO3 powder with molybdenum enriched in 100Mo to 99.5% and mass of 1199 g was measured for 18120 h in a low-background set-up with 4 HP Ge detectors ( volume each one) deep underground (3600 m w.e.) at the Laboratori Nazionali del Gran Sasso of the INFN (Italy). The two γ quanta of 540 keV and of 591 keV emitted in the deexcitation process after a decay of 100Mo to the excited level of 100Ru () are observed in the accumulated data both in coincidence and in the 1-dimensional sum spectrum. The measured half life is: , well in agreement with positive results obtained in previous experiments. Moreover, the limit on charge non-conserving β decay of 100Mo is also set: at 90% C.L.; it corresponds to the limit on CNC admixture in weak currents: . [ABSTRACT FROM AUTHOR]

Abstract: Experimental data on ground- and excited-state properties for all known nuclei with mass number A = 96 have been compiled and evaluated. States populated in radioactive decay, as well as in nuclear reactions, have been considered. For these nuclei, level and decay schemes, as well as tables of nuclear properties, are presented. This work supersedes the 1993 evaluation by L.K. Peker (1993Pe02). In summary, three isomers were identified in 96Ag (2003Ba39,1997Gr02), even though the relative energies were not established. In 96Ru a nuclear fluorescence experiment (2005Li59) determined the spin, branching ratios and transition strengths of dipole excitations; high-spin level properties were reported by 2000Kh02 and 2002Kl07. High spin levels in 96Tc were studied in 2001Bu19. For 96Mo, there are new high-spin data (2000Ch42), as well as low-spin levels produced in () (2007Le05) and () (2004Fr30). High spin data (2005Pa48) were obtained for 96Zr using heavy-ion induced fission. For 96Sr, new levels were deduced using alpha-induced (2005Pa48) and spontaneous fission. The decay of a (10-) isomer in 96Rb was studied by 2005Pi13. Several new mass measurements for neutron rich nuclides have been published, which were used to obtain Q-values and separation energies. [Copyright &y& Elsevier]