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Sample records for seaborgium

  1. First thermochemical property of Seaborgium determined

    Energy Technology Data Exchange (ETDEWEB)

    Tuerler, A. for a LBNL Berkeley - Univ. Bern - FLNR Dubna -GSI Darmstadt - TU Dresden - Chalmers Univ. of Technology Goeteborg - GH Kassel - ITS and LLNL Livermore - Univ. Mainz - Univ. Oslo - FZ Rossendorf - JAERI Tokai - PSI Villigen collaboration

    1997-09-01

    The chemical properties of SgO{sub 2}Cl{sub 2} (element 106 = Seaborgium, Sg) were successfully studied using the On-line Gas Chromatography Apparatus (OLGA III). After chemical separation of Sg the nuclides {sup 265}Sg and {sup 266}Sg were unambiguously identified and their half-lives were determined for the first time. The Sg nuclides were produced from the {sup 248}Cm({sup 22}Ne,4,5n){sup 266,265}Sg reaction at the GSI Darmstadt UNILAC accelerator. Simultaneously, short-lived W nuclides were produced from a small admixture of {sup 152}Gd to the Cm target material. As predicted by relativistic calculations and by extrapolations of chemical properties, it was demonstrated that Sg oxychlorides are indeed less volatile than their lighter homologue Mo- and equally or less volatile than W-oxychlorides. (author) 1 fig., 1 tab., 4 refs.

  2. First aqueous chemistry with Seaborgium (element 106)

    International Nuclear Information System (INIS)

    Schaedel, M.; Bruechle, W.; Schausten, B.; Schimpf, E.; Jaeger, E.; Wirth, G.; Guenther, R.; Gregorich, K.E.; Hoffman, D.C.; Lee, D.M.; Sylwester, E.R.; Nagame, Y.; Oura, Y.

    1996-11-01

    For the first time, chemical separations of element 106 (Seaborgium, Sg) were performed in aqueous solutions. The isotopes 265 Sg and 266 Sg were produced in the 248 Cm+ 22 Ne reaction at a beam energy of 121 MeV. The reaction products were continuously transported by a He(KCl)-jet to the computer-controlled liquid chromatography system ARCA. In 0.1 M HNO 3 /5 x 10 -4 M HF, Sg was found to be eluted within 10 s from 1.6 x 8 mm cation-exchange columns (Aminex A6, 17.5±2 μm) together with the hexavalent Mo- and W-ions, while hexavalent U-ions and tetravalent Zr-, Hf-, and element 104 ions were strongly retained on the column. Element 106 was detected by measuring correlated α-decays of the daughter isotopes 78-s 261 104 and 26-s 257 102. For the isotope 266 Sg, we have evidence for a spontaneous fission branch. It yields a partial spontaneous-fission half-life which is in agreement with recent theoretical predictions. The chemical results show that the most stable oxidation state of Sg in aqueous solution is +6, and that like its homologs Mo and W, Sg forms neutral or anionic oxo- or oxohalide-compounds under the present condition. In these first experiments, Sg exhibits properties very characteristic of group 6 elements, and does not show U-like properties. (orig.)

  3. Sorption behaviour of W, Hf, Lu, U, and Th on ion exchangers from HCl/H2O2 solutions. Model experiments for chemical studies of seaborgium (Sg)

    International Nuclear Information System (INIS)

    Schumann, D.; Andrassy, M.; Nitsche, H.; Misiak, R.; Schaedel, M.; Bruechle, W.; Schausten, B.; Kratz, J.V.

    1997-08-01

    In model experiments with W, Hf, Th, and U radionuclides, a chemical system was developed for the separation of seaborgium from element 104 and heavy actinides, i.e., cation exchange on DOWEX 50 x 8 from solutions containing 0.1-1.0 M HCl and 0.5-2.0 vol.% H 2 O 2 . The system should be suitable for fast on-line experiments if seaborgium exibits a non-uranium-like behaviour. Adding hydrogen peroxide to mixed HCl/HF solutions suppresses the partial sorption of W and, presumably seaborgium, on the cation exchanger. This way, the elution volume can be minimized. Prospects for anion exchange separations of group 6 from 4 elements are also briefly discussed. (orig.)

  4. Nuclear structure studies in the seaborgium region at SHIP

    Energy Technology Data Exchange (ETDEWEB)

    Antalic, S., E-mail: Stanislav.Antalic@fmph.uniba.sk; Andel, B. [Comenius University in Bratislava, 84248 Bratislava (Slovakia); Heßberger, F. P.; Khuyagbaatar, J. [GSI - Helmhotzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Helmholtz Institute in Mainz, 55099 Mainz (Germany); Ackermann, D. [GSI - Helmhotzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); GANIL, 14074 Caen (France); Heinz, S.; Hofmann, S.; Kindler, B.; Laatiaoui, M.; Lommel, B. [GSI - Helmhotzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Kalaninová, Z. [Comenius University in Bratislava, 84248 Bratislava (Slovakia); Laboratory of Nuclear Problems, JINR, 141980 Dubna (Russian Federation); Piot, J.; Vostinar, M. [GANIL, 14074 Caen (France)

    2015-10-15

    New decay data for the isotopes {sup 259}Sg and {sup 255}Rf were obtained at the velocity filter SHIP using an α-decay spectroscopy measurement. Both isotopes were produced and studied via a one neutron evaporation channel in the compound fusion reaction {sup 54}Cr+{sup 208}Pb. New isomeric states were observed and the single-particle level systematics for isotones with 151 and 153 neutrons were extended. A change of the ground-state configuration for the heaviest N = 151 isotones was observed. Detailed Monte-Carlo simulation for the α decay of {sup 259}Sg applying the GEANT4 toolkit was performed and compared with experimental data.

  5. Synthesis and detection of a seaborgium carbonyl complex

    NARCIS (Netherlands)

    Even, J.; Yakushev, A.; Duellmann, Ch E.; Haba, H.; Asai, M.; Sato, T. K.; Brand, H.; Di Nitto, A.; Eichler, R.; Fan, F. L.; Hartmann, W.; Huang, M.; Jaeger, E.; Kaji, D.; Kanaya, J.; Kaneya, Y.; Khuyagbaatar, J.; Kindler, B.; Kratz, J. V.; Krier, J.; Kudou, Y.; Kurz, N.; Lommel, B.; Miyashita, S.; Morimoto, K.; Morita, K.; Murakami, M.; Nagame, Y.; Nitsche, H.; Ooe, K.; Qin, Z.; Schaedel, M.; Steiner, J.; Sumita, T.; Takeyama, M.; Tanaka, K.; Toyoshima, A.; Tsukada, K.; Tuerler, A.; Usoltsev, I.; Wakabayashi, Y.; Wang, Y.; Wiehl, N.; Yamaki, S.

    2014-01-01

    Experimental investigations of transactinoide elements provide benchmark results for chemical theory and probe the predictive power of trends in the periodic table. So far, in gas-phase chemical reactions, simple inorganic compounds with the transactinoide in its highest oxidation state have been

  6. Fulltext PDF

    Indian Academy of Sciences (India)

    the discovery of new elements using particle accelerators. He con- cludes by stating that "we might have reached the limits of the periodic table as a predictive tool". The third article is by Butera on. Glenn Seaborg who holds the record for the discovery of the largest number of elements - one of them named Seaborgium.

  7. Chemistry of the heaviest elements--one atom at a time

    International Nuclear Information System (INIS)

    Hoffman, Darleane C.; Lee, Diana M.

    2000-01-01

    In keeping with the goal of the Viewpoint series of the Journal of Chemical Education, this article gives a 75-year perspective of the chemistry of the heaviest elements, including a 50-year retrospective view of past developments, a summary of current research achievements and applications, and some predictions about exciting, new developments that might be envisioned within the next 25 years. A historical perspective of the importance of chemical separations in the discoveries of the transuranium elements from neptunium (Z=93) through mendelevium (Z=101) is given. The development of techniques for studying the chemical properties of mendelevium and still heavier elements on the basis of measuring the radioactive decay of a single atom (''atom-at-a-time'' chemistry) and combining the results of many separate experiments is reviewed. The influence of relativistic effects (expected to increase as Z 2 ) on chemical properties is discussed. The results from recent atom-at-a-time studies of the chemistry of the heaviest elements through seaborgium (Z=106) are summarized and show that their properties cannot be readily predicted based on simple extrapolation from the properties of their lighter homologues in the periodic table. The prospects for extending chemical studies to still heavier elements than seaborgium are considered and appear promising

  8. Glenn Seaborg's Contributions to Heavy Element Science and the Periodic Table

    International Nuclear Information System (INIS)

    Hobart, David E.

    2012-01-01

    In celebrating the centennial anniversary of the birth of Glenn T. Seaborg it is fitting that we recount and pay tribute to his legacy. Many know of the scientific accomplishments of this man who became a legend and anyone who has attended his lectures can attest to how informative, educational, and entertaining he was. He had a beguiling and whimsical sense of humor and used this to drive home his points and share his passion and quest for discovery. The periodic table is a fundamental cornerstone of science and remains a central unifying principal. Seaborg was the architect of the actinide series of elements and their proper placement in the periodic table and co-discoverer of ten transuranium elements - one of which bears his name, element 106, seaborgium. The work and achievements of this Nobel laureate have touched the lives of many and his legacy will continue for generations to come.

  9. Glann Seaborg's Contributions to Heavy Element Science and the Periodic Table

    Energy Technology Data Exchange (ETDEWEB)

    Hobart, David E. [Los Alamos National Laboratory

    2012-08-17

    In celebrating the centennial anniversary of the birth of Glenn T. Seaborg it is fitting that we recount and pay tribute to his legacy. Many know of the scientific accomplishments of this man who became a legend and anyone who has attended his lectures can attest to how informative, educational, and entertaining he was. He had a beguiling and whimsical sense of humor and used this to drive home his points and share his passion and quest for discovery. The periodic table is a fundamental cornerstone of science and remains a central unifying principal. Seaborg was the architect of the actinide series of elements and their proper placement in the periodic table and co-discoverer of ten transuranium elements - one of which bears his name, element 106, seaborgium. The work and achievements of this Nobel laureate have touched the lives of many and his legacy will continue for generations to come.

  10. Theoretical predictions of properties and gas-phase chromatography behaviour of carbonyl complexes of group-6 elements Cr, Mo, W, and element 106, Sg.

    Science.gov (United States)

    Pershina, V; Anton, J

    2013-05-07

    Fully relativistic, four-component density functional theory electronic structure calculations were performed for M(CO)6 of group-6 elements Cr, Mo, W, and element 106, Sg, with an aim to predict their adsorption behaviour in the gas-phase chromatography experiments. It was shown that seaborgium hexacarbonyl has a longer M-CO bond, smaller ionization potential, and larger polarizability than the other group-6 molecules. This is explained by the increasing relativistic expansion and destabilization of the (n - 1)d AOs with increasing Z in the group. Using results of the calculations, adsorption enthalpies of the group-6 hexacarbonyls on a quartz surface were predicted via a model of physisorption. According to the results, -ΔHads should decrease from Mo to W, while it should be almost equal--within the experimental error bars--for W and Sg. Thus, we expect that in the future gas-phase chromatography experiments it will be almost impossible--what concerns ΔHads--to distinguish between the W and Sg hexacarbonyls by their deposition on quartz.

  11. Superheavy element chemistry. Achievements and perspectives

    International Nuclear Information System (INIS)

    Schaedel, M.

    2007-01-01

    Superheavy elements have been synthesized and chemically characterized one-atom-at-a-time up to element 108. Presently, the quest for element 112 is one of the hottest topics in this field. The transactinide elements 104 to 108 are members of group 4 to 8 of the Periodic Table and element 112 belongs into group 12. Chemical properties of some of these elements, like elements 104 and 105, show stunning deviations from simple extrapolations within their respective group while others exhibit great similarities with their lighter homologues elements. First experiments to investigate seaborgium (Sg, element 106) in aqueous solution were performed. Again, in large international collaborations at the GSI, several gas-phase chemistry experiments were performed with hassium (Hs, element 108). Recently, the highly efficient and very clean separation of Hs was applied for nuclear studies of various Hs nuclides investigating their cross section and their nuclear decay properties in the region of the doubly-magic 270 Hs (Z=108, N=162). To overcome certain limitations of the presently used on-line chemical separations the new TransActinide Separation and Chemistry Apparatus (TASCA) - with a gas-filled recoil separator as a front-end tool - was designed and built at the GSI in a collaborative effort. Presently in its commissioning phase, TASCA shall be a key instrument for a big leap into quantitatively and qualitatively new experiments in the region of superheavy elements. (author)

  12. Chemistry of superheavy elements

    International Nuclear Information System (INIS)

    Schaedel, M.

    2012-01-01

    The chemistry of superheavy elements - or transactinides from their position in the Periodic Table - is summarized. After giving an overview over historical developments, nuclear aspects about synthesis of neutron-rich isotopes of these elements, produced in hot-fusion reactions, and their nuclear decay properties are briefly mentioned. Specific requirements to cope with the one-atom-at-a-time situation in automated chemical separations and recent developments in aqueous-phase and gas-phase chemistry are presented. Exciting, current developments, first applications, and future prospects of chemical separations behind physical recoil separators ('pre-separator') are discussed in detail. The status of our current knowledge about the chemistry of rutherfordium (Rf, element 104), dubnium (Db, element 105), seaborgium (Sg, element 106), bohrium (Bh, element 107), hassium (Hs, element 108), copernicium (Cn, element 112), and element 114 is discussed from an experimental point of view. Recent results are emphasized and compared with empirical extrapolations and with fully-relativistic theoretical calculations, especially also under the aspect of the architecture of the Periodic Table. (orig.)

  13. Chemistry of the superheavy elements.

    Science.gov (United States)

    Schädel, Matthias

    2015-03-13

    The quest for superheavy elements (SHEs) is driven by the desire to find and explore one of the extreme limits of existence of matter. These elements exist solely due to their nuclear shell stabilization. All 15 presently 'known' SHEs (11 are officially 'discovered' and named) up to element 118 are short-lived and are man-made atom-at-a-time in heavy ion induced nuclear reactions. They are identical to the transactinide elements located in the seventh period of the periodic table beginning with rutherfordium (element 104), dubnium (element 105) and seaborgium (element 106) in groups 4, 5 and 6, respectively. Their chemical properties are often surprising and unexpected from simple extrapolations. After hassium (element 108), chemistry has now reached copernicium (element 112) and flerovium (element 114). For the later ones, the focus is on questions of their metallic or possibly noble gas-like character originating from interplay of most pronounced relativistic effects and electron-shell effects. SHEs provide unique opportunities to get insights into the influence of strong relativistic effects on the atomic electrons and to probe 'relativistically' influenced chemical properties and the architecture of the periodic table at its farthest reach. In addition, they establish a test bench to challenge the validity and predictive power of modern fully relativistic quantum chemical models. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  14. Transuranium elements: Past, present, and future

    International Nuclear Information System (INIS)

    Seaborg, G.T.

    1995-01-01

    In this illustrative Account the authors shall concentrate on four of these elements, chosen for their current interest or pivotal role. The story of plutonium is one of the most dramatic in the history of science, and today, plutonium is at the focus of an extraordinary dilemma. Mendelevium (element 101) has played a pivotal role in blazing the trail for the discovery of the heaviest elements on the basis of open-quotes one atom at a timeclose quotes production. Seaborgium (element 106) was recently named in my honor by the discoverers and may be the last element, at least for some time, for which it will be possible to determine many chemical properties. And element 110 represents recent evidence, after a lapse of 10 years, for the discovery of a chemical element. Recent (1994) recommendations of the IUPAC Commission on the Nomenclature of Inorganic Chemistry for the renaming of elements 104-108 have met with widespread rejection. The author is using the names proposed by the acknowledged discoverers (elements 106-109) or, in the case of the disputed elements 104 and 105, the most logical names. 21 refs., 5 figs

  15. Aqueous chemistry of transactinides

    International Nuclear Information System (INIS)

    Schaedel, M.

    2001-01-01

    The aqueous chemistry of the first three transactinide elements is briefly reviewed with special emphasis given to recent experimental results. Short introductory remarks are discussing the atom-at-a-time situation of transactinide chemistry as a result of low production cross-sections and short half-lives. In general, on-line experimental techniques and, more specifically, the automated rapid chemistry apparatus, ARCA, are presented. Present and future developments of experimental techniques and resulting perspectives are outlined at the end. The central part is mainly focussing on hydrolysis and complex formation aspects of the superheavy group 4, 5, and 6 transition metals with F - and Cl - anions. Experimental results are compared with the behaviour of lighter homologous elements and with relativistic calculations. It will be shown that the chemical behaviour of the first superheavy elements is already strongly influenced by relativistic effects. While it is justified to place rutherfordium, dubnium and seaborgium in the Periodic Table of the Elements into group 4, 5 and 6, respectively, it is no more possible to deduce from this position in detail the chemical properties of these transactinide or superheavy elements. (orig.)

  16. Nuclear Science Division 1994 annual report

    International Nuclear Information System (INIS)

    Myers, W.D.

    1995-06-01

    This report describes the activities of the Nuclear Science Division for the period of January 1, 1994, to December 31, 1994. This was a time of significant accomplishment for all of the programs in the Division. Assembly of the solar neutrino detector at the Sudbury Neutrino Observatory is well under way. All of the components fabricated by LBL were shipped to Sudbury early in the year and our efforts are now divided between assisting the assembly of the detector and preparing software for data analysis once the detector is operational in 1996. Much of the activity at the 88-Inch Cyclotron centered on Gammasphere. The open-quotes early implementationclose quotes phase of the detector ended in September. This phase was extremely successful, involving over 60 experiments with nearly 200 users from 37 institutions worldwide. The mechanical structure was installed and the final electronic system is expected to operate in March 1995. The Division concurrently hosted a conference on physics for large γ-ray detector arrays at the Clark Kerr Campus at UC Berkeley in August. This was a very successful meeting, reflecting the enthusiasm for this field worldwide. Also at the Cyclotron, the progress toward weak interaction experiments using ultra-thin sources passed a major milestone with the trapping of radioactive 21 Na atoms. We are now engaged in a major upgrade of the experimental area and the outlook is very promising for these novel experiments. Another highlight of research at the Cyclotron was the confirmation of element 106. This development allowed the original LLNL/LBL discovery team to move forward with their proposal to name this element seaborgium

  17. Nuclear Science Division 1994 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Myers, W.D. [ed.

    1995-06-01

    This report describes the activities of the Nuclear Science Division for the period of January 1, 1994, to December 31, 1994. This was a time of significant accomplishment for all of the programs in the Division. Assembly of the solar neutrino detector at the Sudbury Neutrino Observatory is well under way. All of the components fabricated by LBL were shipped to Sudbury early in the year and our efforts are now divided between assisting the assembly of the detector and preparing software for data analysis once the detector is operational in 1996. Much of the activity at the 88-Inch Cyclotron centered on Gammasphere. The {open_quotes}early implementation{close_quotes} phase of the detector ended in September. This phase was extremely successful, involving over 60 experiments with nearly 200 users from 37 institutions worldwide. The mechanical structure was installed and the final electronic system is expected to operate in March 1995. The Division concurrently hosted a conference on physics for large {gamma}-ray detector arrays at the Clark Kerr Campus at UC Berkeley in August. This was a very successful meeting, reflecting the enthusiasm for this field worldwide. Also at the Cyclotron, the progress toward weak interaction experiments using ultra-thin sources passed a major milestone with the trapping of radioactive {sup 21}Na atoms. We are now engaged in a major upgrade of the experimental area and the outlook is very promising for these novel experiments. Another highlight of research at the Cyclotron was the confirmation of element 106. This development allowed the original LLNL/LBL discovery team to move forward with their proposal to name this element seaborgium.

  18. 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

  19. 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