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[en] The interacting boson model of Arima, Iachello, and co-workers is applied to the even ruthenium isotopes, 96Ru∼116Ru. Excitation energies, electromagnetic transition strengths, quadrupole and magnetic dipole moments, and Δ(E2/M1) mixing ratios have been described systematically. Mixed symmetry states are investigated. It is seen that the properties of low-lying levels in these isotopes, for which the comparison between experiment and theory is possible, can be satisfactorily characterized by the Interacting Boson Model-2.
[en] The isotopic composition of Ru has been measured mass spectrometrically in an acid resistant residue of the Allende meteorite and in one magnetic and three non-magnetic portions of type-B inclusions, two from Allende and one from Leoville. Normalized to 96Ru/101Ru = 0.324851, all 98Ru/101Ru and 99Ru/101Ru ratios were found to be indistinguishable from the terrestrial values within 1.6 permil and 0.4 permil respectively. Thus, in the sampled reservoirs we find no evidence for different relative amounts of radiogenic 98Ru and 99Ru from the decay of now extinct 4.2 Myr-98Tc and 0.21 Myr-99Tc. 100Ru/101Ru and 104Ru/101Ru were found to deviate from the terrestrial norm by more than 2 σ (<= 0.6 permil) in one and two cases, respectively. Since terrestrial ratios were occasionally compromised by molecular interferences to an even larger extent, these overabundances cannot be unambiguously attributed to nonlinear isotope anomalies in the samples. The 102Ru/101Ru ratio is normal in two aliquants of the acid resistant Allende residue but higher than normal by up to 0.35 permil in all four inclusion samples. There is a possibility, although very remote, that these excesses are due to contamination by a 102Ru spike. A less conservative interpretation of the data and normalization to 104Ru/101Ru rather than to 96Ru/101Ru results in overabundances of the light p-process isotopes 96Ru and 98Ru in the non-magnetic portions of all three inclusions. (author)
[en] A technique has been devised to date Precambrian uranium ore samples by measuring the concentrations of 238U and of ruthenium isotopes that result from the spontaneous fission of 238U. The concentration of the latter depends on (1) the amount of 238U present, (2) the spontaneous fission decay rate, (3) the ruthenium fission yields for 238U, and (4) the duration of spontaneous fission, i.e., the age of the ore. Ruthenium in Precambrian ores has been identified as being from the natural abundance, the spontaneous fission of 238U, and the more variable neutron-induced fission of 235U. The contribution from ''common'' natural ruthenium is typically 1 ppB and is determined from the isotopes of mass 96, 98, and 100, which are not produced in fission. The ratio of isotopes of mass 99, 101, 102, and 104 for 238U spontaneous fission has been found to be significantly different from that ratio for 235U neutron-induced fission. Hence, the amount of ruthenium in an ore sample which results solely from 238U spontaneous fission can be determined. Several Precambrian uranium ore samples have been dated using this technique, and the ages compare favorably to values determined by other techniques. The component of ruthenium resulting from neutron-induced fission of 235U varied between about 5 and 50 percent of the amount from 238U spontaneous fission, and the component of common ruthenium was typically about 25 percent of the total ruthenium. This uranium--ruthenium technique should complement existing radiogenic dating techniques because it relies on a radiogenic product whose geochemistry is different from that of products or intermediates in the other decay sequences
[en] Metallic ruthenium, its alloys, and compounds with other metals have a number of valuable and specific properties which allow the usage of ruthenium in various fields of modern technology, which is described here. In the atomic technology, Ru can be used in the building of reactors as a material of construction since its isotopes don't possess a high neutron capture cross section. Ruthenium is used for the preparation of γ- and β-ray emission sources. Isotopes Ru-103 and Ru-106 are widely used as tracers. They are successfully used for the monitoring of production, for the development of new technological and analytical methods of the extraction of Ru, for the cleansing of other valuable metals from Ru, for the monitoring of the thickness of Ru microfilm on the substrate, and for the monitoring of Ru losses in various processes. In the nuclear reactor, during the process of uranium and plutonium decay, large amounts of stable Ru isotopes are formed together with radioactive isotopes. In such a manner, a nuclear reactor can supply Ru. Special attention must be paid to the usage of direct coordination Ru compounds. Ru and its compounds possess a large number of very valuable properties, many of the secrets of Ru must still be discovered. It can be presumed that the demand for ruthenium will grow in the forthcoming years and the range and volume of its applications will increase