Search

The influence of ruthenium addition at different doping concentrations on the optical properties and holographic behavior of Bi4Ge3O12 crystals is investigated. Doped Bi4Ge3O12 single crystals are grown by using the Czochralski technique. The distribution coefficient of each crystal is measured to determine the concentration of a doped ruthenium element. Holographic experiments are performed. Ruthenium is found to make Bi4Ge3O12 sensitive in the red spectral range. Thermal annealing and ultraviolet exposure have been used to modify the defect structure and corresponding absorption band of each crystal such that the holographic recording has been influenced. The diffraction efficiency increases with increasing of ruthenium content, especially after irradiation by ultraviolet light. [ABSTRACT FROM AUTHOR]

An efficient numerical method for the temporal and spatial localization of an unknown point source of an atmospheric tracer is proposed. The method, which is based on inverse modelling techniques, employs available data from a network of ground-level stations on the condition that the measurements represent the plume geographically and temporally. The method, which employs a level-of-agreement approach, is applied to the October 2017 air concentration measurements of Ru-106 in Europe. [ABSTRACT FROM AUTHOR]

Collective properties of neutron-rich Ru, Pd, and Cd isotopes are reviewed, combining the original results from the IGISOL β-decay experiments with recent experimental and theoretical progress. The transitional nature of Ru and Pd nuclei is discussed via the low-lying level systematics, including the low-lying 0  +  states. Although the role of an anharmonic quadrupole vibrator in Cd nuclei was recently questioned, level systematics for the three-phonon quintuplet in 116,118,120Cd are presented, and an outlook of the spectroscopic methods for the level lifetime or B( E2) values is given. [ABSTRACT FROM AUTHOR]

Photophysics of the MLCT excited-state of [Ru(bpy)(tpy)(OH2)]2+ (1) and [Ru(bpy)(tpy)(OD2)]2+ (2) (bpy = 2,2'-bipyridine and tpy = 2,2':6',2'-terpyridine) have been investigated in room-temperature H2O and D2O using ultrafast transient pump-probe spectroscopy. An inverse isotope effect is observed in the ground-state recovery for the two complexes. These data indicate control of excited-state lifetime via a pre-equilibrium between the ³MLCT state that initiates H-bond dynamics with the solvent and the ³MC state that serves as the principal pathway for nonradiative decay. [ABSTRACT FROM AUTHOR]

116Ru and 118Ru have been studied via β-delayed y-ray spectroscopy of nuclei produced in fragmentation reactions at the Radioactive Ion-Beam Factory (RIBF) facility. Level schemes with positive-parity states up to spin 7=6 have been constructed. The results have been discussed in terms of the interacting boson model, the algebraic collective model, and total Routhian surfaces. We conclude that the very neutron-rich nuclei still show many features associated with triaxial y-soft nuclei, represented by the 0(6) symmetry, but are approaching a spherical structure, the U(5) symmetry, with increasing neutron number towards the N = 82 shell closure. In 118Ru, hints of a shape transition in the ground state have been observed. [ABSTRACT FROM AUTHOR]

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: When radioactive isotopes that decay by α, β−, β+ and electron-capture transitions are placed in a conducting host material, it has recently been claimed that their half-lives show a significant dependence on temperature—up to a 6% difference between room temperature and 12K. We have refuted two of these claims by measuring: (1) the β− decay of 198Au in gold, for which we find the half life to be the same within 0.04% between room temperature and 19K; and (2) the electron-capture decay of 97Ru in ruthenium, for which we find any half-life difference to be <0.1%. [Copyright &y& Elsevier]

Abstract: The coincidence detection efficiency of the TUNL-ITEP apparatus designed for measuring half-life times of two-neutrino double-beta () decay transitions to excited final states in daughter nuclei has been measured with a factor of 2.4 improved accuracy. In addition, the previous measuring time of 455 days for the study of the 100Mo decay to the first excited state in 100Ru has been increased by 450 days, and a new result (combined with the previous measurement obtained with the same apparatus) for this transition is presented: . Measured decay half-life times to excited states can be used to test the reliability of nuclear matrix element calculations needed for determining the effective neutrino mass from zero-neutrino double-beta decay data. We also present new limits for transitions to higher excited states in 100Ru which, if improved, may be of interest for more exotic conjectures, like a bosonic component to neutrino statistics. [Copyright &y& Elsevier]

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]

The very neutron-deficient 91,92,93Rh and 90,91Ru nuclei were produced in 58Ni(36,40Ar, xn yp) fusion-evaporation reactions. Reaction products leaving the target were stopped in a gas cell and selectively laser ionised before mass separation using the LISOL setup. Data were collected in singles and coincidence formats to investigate β-delayed and isomeric γ decays. Ground-state decays of 91,93Rh to excited states in the daughter nucleus were identified for the first time and the decay schemes of 90,91Ru were expanded. The low-spin isomeric decay of 92Rh was identified for the first time and detail added to the decay scheme of the known high-spin state. Results are discussed in terms of comparison with shell model calculations. β-delayed proton activity in the lighter 90Rh and 89Ru isotopes was also investigated and upper limits for this decay mode in these two nuclei have been included. [ABSTRACT FROM AUTHOR]