Dirac-Hartree-Fock studies of X-ray transitions in meitnerium

International Nuclear Information System (INIS)

Thierfelder, C.; Schwerdtfeger, P.; Hessberger, F.P.; Hofmann, S.

2008-01-01

The K -shell and L -shell ionizations potentials for 268 109 Mt were calculated at the Dirac-Hartree-Fock level taking into account quantum electrodynamic and finite nuclear-size effects. The K α1 transition energies for different ionization states are accurately predicted and compared with recent experiments in the α -decay of 272 111 Rg. (orig.)

2007 Nuclear Data Review

International Nuclear Information System (INIS)

Holden, N.E.

2008-01-01

The results of a review and evaluation of neutron and non-neutron nuclear data published in the scientific literature are presented. The status of new chemical elements is examined. Data on revised values for the isotopic composition of the elements are reviewed and recommended values are presented. Half-lives of very long-lived nuclides are presented, including double beta decay, double electron capture, long-lived alpha decay and long-lived beta decay. Data from new measurements on the very heavy elements (trans-meitnerium elements) are discussed and tabulated. The first observation of the radioactive decay mode of the free neutron is discussed. New measurements that have expanded the neutron drip line for magnesium and aluminum are discussed. Data on recent neutron cross-section and resonance integral measurements are also discussed

The synthesis of the deformed superheavy elements 107 to 111

International Nuclear Information System (INIS)

Armbuster, P.

1995-01-01

By inflight separation, implantation into Si-detector arrays, and correlation analysis of subsequent α-decay chains many isotopes were discovered at GSI since 1980, among others the elements Nielsbohriurn, Hassium and Meitnerium. The sensitivity of the method allows to identify an element by one decay chain, as we demonstrated for the case of 266 Mt. After a break of our work during the time when the new accelerator system SIS-FRS-ESR was installed (1989-1993) at GSI, and many improvements of our system EZR-UNILAC-SHIP accomplished, we restarted element synthesis in 1994. The synthesis of the isotopes 269 110, 271 110, and 272 111 of the new elements Z--110 and Z=l11 was a first success at the end of 1994. This discovery is in the center of this presentation. The reaction mechanism, a one-step, cold and compact rearrangement process at a level of some 10 -36 cm 2 is discussed. Cross sections and excitation functions systematically studied allow to extrapolate to the next element Z=112, which seems not to be out of reach

Developments for transactinide chemistry experiments behind the gas-filled separator TASCA

Energy Technology Data Exchange (ETDEWEB)

Even, Julia

2011-12-13

synthesised carbonyl complexes were identified by nuclear decay spectroscopy. Some complexes were studied with isothermal chromatography or thermochromatography methods. The chromatograms were compared with Monte Carlo Simulations to determine the adsorption enthalpyrnon silicon dioxide and on gold. These simulations based on existing codes, that were modified for the different geometries of the chromatography channels. All observed adsorption enthalpies (on silcon oxide as well as on gold) are typical for physisorption. Additionally, the thermalstability of some of the carbonyl complexes was studied. This showed that at temperatures above 200 C therncomplexes start to decompose. It was demonstrated that carbonyl-complex chemistry is a suitable method to study rutherfordium, dubnium, seaborgium, bohrium, hassium, and meitnerium. Until now, only very simple, thermally stable compounds have been synthesized in the gas-phase chemistry of the transactindes. With the synthesis of transactinide-carbonyl complexes a new compound class would be discovered. Transactinide chemistry would reach the border between inorganic and metallorganic chemistry. Furthermore, the in-situ synthesised carbonyl complexes would allow nuclear spectroscopy studies under low background conditions making use of chemically prepared samples. [German] Die vorliegende Arbeit befasst sich mit der Entwicklung von Experimenten hinter dem gasgefuellten Separator TASCA (TransActinide Separator and Chemistry Apparatus) zur Studie des chemischen Verhaltens der Transactinide. Zum einen wurde die Moeglichkeit der elektrochemischen Abscheidung kurzlebiger Isotope der Elemente Ruthenium und Osmium auf Goldelektroden im Hinblick auf ein Experiment mit Hassium untersucht. Aus der Literatur ist bekannt, dass bei der elektrochemischen Abscheidung einzelner Atome das Abscheidepotential signifikant vom Nernst-Potential abweicht. Die Verschiebung des Potentials haengt von der Adsorptionsenthalpie des abzuscheidenden Elements

Developments for transactinide chemistry experiments behind the gas-filled separator TASCA

International Nuclear Information System (INIS)

Even, Julia

2011-01-01

synthesised carbonyl complexes were identified by nuclear decay spectroscopy. Some complexes were studied with isothermal chromatography or thermochromatography methods. The chromatograms were compared with Monte Carlo Simulations to determine the adsorption enthalpyrnon silicon dioxide and on gold. These simulations based on existing codes, that were modified for the different geometries of the chromatography channels. All observed adsorption enthalpies (on silcon oxide as well as on gold) are typical for physisorption. Additionally, the thermalstability of some of the carbonyl complexes was studied. This showed that at temperatures above 200 C therncomplexes start to decompose. It was demonstrated that carbonyl-complex chemistry is a suitable method to study rutherfordium, dubnium, seaborgium, bohrium, hassium, and meitnerium. Until now, only very simple, thermally stable compounds have been synthesized in the gas-phase chemistry of the transactindes. With the synthesis of transactinide-carbonyl complexes a new compound class would be discovered. Transactinide chemistry would reach the border between inorganic and metallorganic chemistry. Furthermore, the in-situ synthesised carbonyl complexes would allow nuclear spectroscopy studies under low background conditions making use of chemically prepared samples. [de