WorldWideScience

Sample records for bohrium

  1. From bohrium to copernicium and beyond SHE research at SHIP

    Energy Technology Data Exchange (ETDEWEB)

    Münzenberg, G., E-mail: G.Muenzenberg@gsi.de [GSI Helmholtzzentrum für Schwerionenforschung, Planckstrasse 1, 64291 Darmstadt (Germany); Manipal Centre for Natural Sciences, Manipal University, Manipal 576104, Karnataka (India)

    2015-12-15

    Heavy-element research with SHIP at GSI is reviewed including the discovery of the chemical elements bohrium to copernicium, experimental developments, cold fusion of heavy ions, and the discovery of a shell region around hassium. Elements bohrium and heavier are located beyond the limit of liquid-drop stability. They exist by shell stabilization. A universal, sensitive, and fast method: in-flight separation and identification of single atomic nuclei has been developed with the velocity filter SHIP and the detector system to measure decay sequences of individual atoms. Research with single atomic nuclei including detection methods, identification, and physics results will be discussed. Experiments with actinide targets as well as prospects with NUSTAR at FAIR will be addressed.

  2. Properties of an α Particle in a Bohrium 270 Nucleus under the Generalized Symmetric Woods-Saxon Potential

    Directory of Open Access Journals (Sweden)

    Bekir Can LÜTFÜOĞLU

    2017-04-01

    Full Text Available The energy eigenvalues and the wave functions of an α particle in a Bohrium 270 nucleus have been calculated by solving Schrödinger equation for Generalized Symmetric Woods-Saxon potential. Using the energy spectrum by excluding and including the quasi-bound eigenvalues, entropy, internal energy, Helmholtz energy, and specific heat, as functions of reduced temperature have been calculated. Stability and emission characteristics have been interpreted in terms of the wave and thermodynamic functions. The kinetic energy of a decayed α particle was calculated using the quasi-bound states, which has been found close to the experimental value.

  3. BPU Simulator

    DEFF Research Database (Denmark)

    Rehr, Martin; Skovhede, Kenneth; Vinter, Brian

    2013-01-01

    in that process. Our goal is to support all execution platforms, and in this work we introduce the Bohrium Processing Unit, BPU, which will be the FPGA backend for Bohrium. The BPU is modeled as a PyCSP application, and the clear advantages of using CSP for simulating a new CPU is described. The current Py...

  4. Mendeleev's principle against Einstein's relativity: news from the chemistry of superheavy elements

    Energy Technology Data Exchange (ETDEWEB)

    Gaeggeler, Heinz W [Department of Chemistry and Biochemistry, University of Bern, Bern (Switzerland)

    2009-12-31

    The review briefly considers the problems of synthesis and chemical identification of superheavy elements. The specific features of their properties are determined by the relativistic effects. The synthesis and chemical investigations into bohrium and element 112 are discussed as examples.

  5. Automatic Parallelization of Scientific Application

    DEFF Research Database (Denmark)

    Blum, Troels

    performance gains. Scientists working with computer simulations should be allowed to focus on their field of research and not spend excessive amounts of time learning exotic programming models and languages. We have with Bohrium achieved very promising results by starting out with a relatively simple approach...

  6. Srinivasan Natarajan

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. Srinivasan Natarajan. Articles written in Resonance – Journal of Science Education. Volume 5 Issue 5 May 2000 pp 95-100 Research News. Bohrium - A New Element in the Periodic Table · Srinivasan Natarajan · More Details Fulltext PDF ...

  7. Battling memory requirements of array programming through streaming

    DEFF Research Database (Denmark)

    Kristensen, Mads Ruben Burgdorff; Avery, James Emil; Blum, Troels

    2016-01-01

    A barrier to efficient array programming, for example in Python/NumPy, is that algorithms written as pure array operations completely without loops, while most efficient on small input, can lead to explosions in memory use. The present paper presents a solution to this problem using array streaming......, implemented in the automatic parallelization high-performance framework Bohrium. This makes it possible to use array programming in Python/NumPy code directly, even when the apparent memory requirement exceeds the machine capacity, since the automatic streaming eliminates the temporary memory overhead...... by performing calculations in per-thread registers. Using Bohrium, we automatically fuse, JIT-compile, and execute NumPy array operations on GPGPUs without modification to the user programs. We present performance evaluations of three benchmarks, all of which show dramatic reductions in memory use from...

  8. Combining high productivity with high performance on commodity hardware

    DEFF Research Database (Denmark)

    Skovhede, Kenneth

    -like compiler for translating CIL bytecode on the CELL-BE. I then introduce a bytecode converter that transforms simple loops in Java bytecode to GPGPU capable code. I then introduce the numeric library for the Common Intermediate Language, NumCIL. I can then utilizing the vector programming model from Num......CIL and map this to the Bohrium framework. The result is a complete system that gives the user a choice of high-level languages with no explicit parallelism, yet seamlessly performs efficient execution on a number of hardware setups....

  9. Paul Scherrer Institute Scientific Report 1999. Volume I: Particles and Matter

    International Nuclear Information System (INIS)

    Gobrecht, J.; Gaeggeler, H.; Herlach, D.; Junker, K.; Kettle, P.-R.; Kubik, P.; Zehnder, A.

    2000-01-01

    Although originally planned for fundamental research in nuclear physics, the particle beams of pions, muons, protons and neutrons are now used in a large variety of disciplines in both natural science and medicine. The beams at PSI have the world's highest intensities and therefore allow certain experiments to be performed, which would not be possible elsewhere. The highlight of research this year was the first-ever determination of the chemical properties of the superheavy element 107 Bohrium. This was undertaken, by an international team led by H. Gaeggeler of PSI's Laboratory for Radiochemistry. Bohrium was produced by bombarding a Berkelium target with Neon ions from the Injector I cyclotron and six atoms were detected after having passed through an online gas chromatography device. At the Laboratory for Particle Physics the focus has shifted from nuclear physics to elementary particle physics with about a fifty-fifty split between investigations of rare processes or particle decays using the high intensity muon, pion and recently also polarized neutron beams of PSI, and research at the highest energy frontier at CERN (Geneva) and DESY (Hamburg). Important space instrumentation has been contributed by the Laboratory for Astrophysics to the European Space Agency and NASA satellite programmes. The Laboratory for Micro and Nanotechnology continued to focus on research into molecular nanotechnology and SiGeC nanostructures, the latter with the aim of producing silicon based optoelectronics. Progress in 1999 in these topical areas is described in this report. A list of scientific publications in 1999 is also provided

  10. Paul Scherrer Institute Scientific Report 1999. Volume I: Particles and Matter

    Energy Technology Data Exchange (ETDEWEB)

    Gobrecht, J; Gaeggeler, H; Herlach, D; Junker, K; Kettle, P -R; Kubik, P; Zehnder, A [eds.

    2000-07-01

    lthough originally planned for fundamental research in nuclear physics, the particle beams of pions, muons, protons and neutrons are now used in a large variety of disciplines in both natural science and medicine. The beams at PSI have the world's highest intensities and therefore allow certain experiments to be performed, which would not be possible elsewhere. The highlight of research this year was the first-ever determination of the chemical properties of the superheavy element {sup 107} Bohrium. This was undertaken, by an international team led by H. Gaeggeler of PSI's Laboratory for Radiochemistry. Bohrium was produced by bombarding a Berkelium target with Neon ions from the Injector I cyclotron and six atoms were detected after having passed through an online gas chromatography device. At the Laboratory for Particle Physics the focus has shifted from nuclear physics to elementary particle physics with about a fifty-fifty split between investigations of rare processes or particle decays using the high intensity muon, pion and recently also polarized neutron beams of PSI, and research at the highest energy frontier at CERN (Geneva) and DESY (Hamburg). Important space instrumentation has been contributed by the Laboratory for Astrophysics to the European Space Agency and NASA satellite programmes. The Laboratory for Micro and Nanotechnology continued to focus on research into molecular nanotechnology and SiGeC nanostructures, the latter with the aim of producing silicon based optoelectronics. Progress in 1999 in these topical areas is described in this report. A list of scientific publications in 1999 is also provided.

  11. Paul Scherrer Institute Scientific Report 1999. Volume I: Particles and Matter

    Energy Technology Data Exchange (ETDEWEB)

    Gobrecht, J.; Gaeggeler, H.; Herlach, D.; Junker, K.; Kettle, P.-R.; Kubik, P.; Zehnder, A. [eds.

    2000-07-01

    lthough originally planned for fundamental research in nuclear physics, the particle beams of pions, muons, protons and neutrons are now used in a large variety of disciplines in both natural science and medicine. The beams at PSI have the world's highest intensities and therefore allow certain experiments to be performed, which would not be possible elsewhere. The highlight of research this year was the first-ever determination of the chemical properties of the superheavy element {sup 107} Bohrium. This was undertaken, by an international team led by H. Gaeggeler of PSI's Laboratory for Radiochemistry. Bohrium was produced by bombarding a Berkelium target with Neon ions from the Injector I cyclotron and six atoms were detected after having passed through an online gas chromatography device. At the Laboratory for Particle Physics the focus has shifted from nuclear physics to elementary particle physics with about a fifty-fifty split between investigations of rare processes or particle decays using the high intensity muon, pion and recently also polarized neutron beams of PSI, and research at the highest energy frontier at CERN (Geneva) and DESY (Hamburg). Important space instrumentation has been contributed by the Laboratory for Astrophysics to the European Space Agency and NASA satellite programmes. The Laboratory for Micro and Nanotechnology continued to focus on research into molecular nanotechnology and SiGeC nanostructures, the latter with the aim of producing silicon based optoelectronics. Progress in 1999 in these topical areas is described in this report. A list of scientific publications in 1999 is also provided.

  12. The gas phase oxide and oxyhydroxide chemistry of trace amounts of rhenium

    International Nuclear Information System (INIS)

    Eichler, R.; Eichler, B.; Jost, D.T.; Dressler, R.; Tuerler, A.; Gaeggeler, H.W.

    1999-01-01

    In preparation of experiments to investigate the chemical properties of bohrium (Bh, element 107) the behaviour of Re, its lighter homologue in group 7, was studied in different oxidizing chemical systems. The adsorption data of Re oxide and oxyhydroxide compounds on quartz surfaces were evaluated from results of thermochromatography experiments and confirmed in isothermal gas chromatography experiments applying 1 cm as standard state for the simple gas adsorption process: X(g) ↔ X(ads) (X = ReO 3 , HReO 4 ) ΔH ads (ReO 3 ) = -190 ± 10 kJ/mol; ΔS ads (ReO 3 ) = -179±30 J/mol K; ΔH ads (HReO 4 ) = -77 ± 5 kJ/mol; ΔS ads (HReO 4 ) = -187±50 J/mol K. An on-line separation method for oxides and oxyhydroxides of short lived Re isotopes using isothermal high temperature gas-solid adsorption chromatography was developed. Separation yields and times of group 7 elements from lanthanides (model for actinides), polonium and bismuth were determined using the model isotopes 169,170,174,176 Re, 152-155 Er, 151-154 Ho, 218 Po, and 214 Bi. An updated correlation function between the microscopic adsorption enthalpy and the macroscopic sublimation enthalpy was calculated from the experimental adsorption data of this work and literature data. (orig.)

  13. Road dust and its effect on human health: a literature review

    Science.gov (United States)

    2018-01-01

    The purpose of this study was to determine the effects of road dust on human health. A PubMed search was used to extract references that included the words “road dust” and “health” or “fugitive dust” and “health” in the title or abstract. A total of 46 references were extracted and selected for review after the primary screening of 949 articles. The respiratory system was found to be the most affected system in the human body. Lead, platinum-group elements (platinum, rhodium, and bohrium), aluminum, zinc, vanadium, and polycyclic aromatic hydrocarbons were the components of road dust that were most frequently referenced in the articles reviewed. Road dust was found to have harmful effects on the human body, especially on the respiratory system. To determine the complex mechanism of action of various components of road dust on the human body and the results thereof, the authors recommend a further meta-analysis and extensive risk-assessment research into the health impacts of dust exposure. PMID:29642653

  14. 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.)

  15. Properties of Group Five and Group Seven transactinium elements

    Energy Technology Data Exchange (ETDEWEB)

    Wilk, Philip A. [Univ. of California, Berkeley, CA (United States)

    2001-05-01

    The detection and positive identification of the short-lived, low cross section isotopes used in the chemical studies of the heaviest elements are usually accomplished by measuring their alpha-decay, thus the nuclear properties of the heaviest elements must be examined simultaneously with their chemical properties. The isotopes 224 Pa and 266,267 Bh have been studied extensively as an integral part of the investigation of the heaviest members of the groups five and seven of the periodic table. The half-life of 224 Pa was determined to be 855 ±19 ms by measuring its alpha-decay using our rotating wheel, solid state detector system at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron. Protactinium was produced by bombardment of a bismuth target. New neutron rich isotopes, 267 Bh and 266 Bh, were produced in bombardments of a 249 Bk target and their decay was observed using the rotating wheel system. The 266 Bh that was produced decays with a half-life of approximately 1 s by emission of alpha particles with an average energy of 9.25 plus/minus 0.03 MeV. 267 Bh was observed to decay with a 17 s half-life by emission of alpha-particles with an average energy of 8.83 plus/minus 0.03 MeV. The chemical behavior of hafnium, Ha (element 105) was investigated using the fast on-line continuous liquid extraction and detection system SISAK-LISSY. Hafnium was not observed in this experiment following transport and extraction. Protactinium was used as on-line test of the apparatus to determine the experimental efficiency of the entire system. Unfortunately, the amount of protactinium observed after the extraction, compared to the amount produced, was extremely small, only 2.5%. The extraction of the protactinium isotope indicated the efficiency of the apparatus was too low to observe the extraction of hafnium. The chemical behavior of oxychloride compounds of bohrium was

  16. Properties of Group Five and Group Seven transactinium elements

    International Nuclear Information System (INIS)

    Wilk, Philip A.

    2001-01-01

    The detection and positive identification of the short-lived, low cross section isotopes used in the chemical studies of the heaviest elements are usually accomplished by measuring their alpha-decay, thus the nuclear properties of the heaviest elements must be examined simultaneously with their chemical properties. The isotopes 224 Pa and 266,267 Bh have been studied extensively as an integral part of the investigation of the heaviest members of the groups five and seven of the periodic table. The half-life of 224 Pa was determined to be 855 plus/minus19 ms by measuring its alpha-decay using our rotating wheel, solid state detector system at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron. Protactinium was produced by bombardment of a bismuth target. New neutron rich isotopes, 267 Bh and 266 Bh, were produced in bombardments of a 249 Bk target and their decay was observed using the rotating wheel system. The 266 Bh that was produced decays with a half-life of approximately 1 s by emission of alpha particles with an average energy of 9.25 plus/minus 0.03 MeV. 267 Bh was observed to decay with a 17 s half-life by emission of alpha-particles with an average energy of 8.83 plus/minus 0.03 MeV. The chemical behavior of hafnium, Ha (element 105) was investigated using the fast on-line continuous liquid extraction and detection system SISAK-LISSY. Hafnium was not observed in this experiment following transport and extraction. Protactinium was used as on-line test of the apparatus to determine the experimental efficiency of the entire system. Unfortunately, the amount of protactinium observed after the extraction, compared to the amount produced, was extremely small, only 2.5%. The extraction of the protactinium isotope indicated the efficiency of the apparatus was too low to observe the extraction of hafnium. The chemical behavior of oxychloride compounds of bohrium was investigated by isothermal gas adsorption chromatography in a quartz column at 180, 150

  17. New elements - approaching Z=114

    International Nuclear Information System (INIS)

    Hofmann, S.

    1998-03-01

    The search for new elements is part of the broader field of investigations of nuclei at the limits of stability. In two series of experiments at SHIP, six new elements (Z=107-112) were synthesized via fusion reactions using 1n-deexcitation channels and lead or bismuth targets. The isotopes were unambiguously identified by means of α-α correlations. Not fission, but alpha decay is the dominant decay mode. The collected decay data establish a means of comparison with theoretical data. This aids in the selection of appropriate models that describe the properties of known nuclei. Predictions based on these models are useful in the preparation of the next generation of experiments. Cross-sections decrease by two orders of magnitude from bohrium (Z=107) to element 112, for which a cross-section of 1 pb was measured. The development of intense beam currents and sensitive detection methods is essential for the production and identification of still heavier elements and new isotopes of already known elements, as well as the measurement of small α-, β- and fission-branching ratios. An equally sensitive set-up is needed for the measurement of excitation functions at low cross-sections. Based on our results, it is likely that the production of isotopes of element 114 close to the island of spherical super heavy elements (SHE) could be achieved by fusion reactions using 208 Pb targets. Systematic studies of the reaction cross-sections indicate that the transfer of nucleons is an important process for the initiation of fusion. The data allow for the fixing of a narrow energy window for the production of SHE using 1n-emission channels. (orig.)

  18. MicroSISAK for the chemistry of the heaviest elements

    International Nuclear Information System (INIS)

    Hild, Daniel

    2012-01-01

    This thesis describes experiments with an apparatus called MicroSISAK which is able to perform liquid-liquid-extraction on a microliter-scale. Two immiscible liquids are mixed in a microstructured mixer unit and separated again via a Teflon membrane. In the first experiments, different extraction systems were explored for elements of the groups 4 and 7 of the periodic table. Their results were compared with those from batch experiments. The initial achieved extraction yields were insufficient for the envisaged experiments, for which reason different modifications were arranged to obtain improvements. With the aid of a heating element, which was connected to the MicroSISAK apparatus, one was able to rise the temperature for the extraction inside. This led to the expected increasing of the extraction yield. Furthermore the MikroSISAK apparatus was modified by the Institut fuer Mikrotechnik Mainz, which had developed and constructed this apparatus. The contact time of the two phases between the mixer and the separation unit was extended. This also led to an increased yield. Now the performance appeared to be sufficient to connect the apparatus to the TRIGAreactor Mainz to perform online-experiments. Fission products (technetium) produced in a nuclear reaction were guided to the MicroSISAK apparatus to separate them and to detect their decay in a γ-ray detector. Apart from the successful separations, the experiments also proved the functionality of a new degasser system and that an adequate detection system can be coupled to MicroSISAK. With this, the prerequisites for the vision of an application of MicroSISAK are realised: The investigation of the chemical properties of short-lived superheavy elements (SHE) at a heavy-ion accelerator. It is obvious to plan such an experiment for the heavy homolog of technetium, element 107, bohrium.

  19. Odd-Z Transactinide Compound Nucleus Reactions Including the Discovery of 260Bh

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Sarah L. [Univ. of California, Berkeley, CA (United States)

    2008-01-01

    Several reactions producing odd-Z transactinide compound nuclei were studiedwith the 88-Inch Cyclotron and the Berkeley Gas-Filled Separator at the Lawrence Berkeley National Laboratory. The goal was to produce the same compound nucleus ator near the same excitation energy with similar values of angular momentum via differentnuclear reactions. In doing so, it can be determined if there is a preference in entrancechannel, because under these experimental conditions the survival portion of Swiatecki, Siwek-Wilcznska, and Wilczynski's"Fusion By Diffusion" model is nearly identical forthe two reactions. Additionally, because the same compound nucleus is produced, theexit channel is the same. Four compound nuclei were examined in this study: 258Db, 262Bh, 266Mt, and 272Rg. These nuclei were produced by using very similar heavy-ion induced-fusion reactions which differ only by one proton in the projectile or target nucleus (e.g.: 50Ti + 209Bi vs. 51V + 208Pb). Peak 1n exit channel cross sections were determined for each reaction in each pair, and three of the four pairs' cross sections were identical within statistical uncertainties. This indicates there is not an obvious preference of entrancechannel in these paired reactions. Charge equilibration immediately prior to fusionleading to a decreased fusion barrier is the likely cause of this phenomenon. In addition to this systematic study, the lightest isotope of element 107, bohrium, was discovered in the 209Bi(52Cr,n) reaction. 260Bh was found to decay by emission of a 10.16 MeV alpha particle with a half-life of 35$+19\\atop{-9}$ ms. The cross section is 59 pb at an excitation energy of 15.0 MeV. The effect of the N = 152 shell is also seen in this isotope's alpha particle energy, the first evidence of such an effect in Bh. All reactions studied are also compared to model predictions by Swiatecki

  20. Odd-Z Transactinide Compound Nucleus Reactions Including the Discovery of 260Bh

    International Nuclear Information System (INIS)

    Nelson, Sarah L; Nelson, Sarah L

    2008-01-01

    Several reactions producing odd-Z transactinide compound nuclei were studied with the 88-Inch Cyclotron and the Berkeley Gas-Filled Separator at the Lawrence Berkeley National Laboratory. The goal was to produce the same compound nucleus at or near the same excitation energy with similar values of angular momentum via different nuclear reactions. In doing so, it can be determined if there is a preference in entrance channel, because under these experimental conditions the survival portion of Swiatecki, Siwek-Wilcznska, and Wilczynski's 'Fusion By Diffusion' model is nearly identical for the two reactions. Additionally, because the same compound nucleus is produced, the exit channel is the same. Four compound nuclei were examined in this study: 258Db, 262Bh, 266Mt, and 272Rg. These nuclei were produced by using very similar heavy-ion induced-fusion reactions which differ only by one proton in the projectile or target nucleus (e.g.: 50Ti + 209Bi vs. 51V + 208Pb). Peak 1n exit channel cross sections were determined for each reaction in each pair, and three of the four pairs; cross sections were identical within statistical uncertainties. This indicates there is not an obvious preference of entrance channel in these paired reactions. Charge equilibration immediately prior to fusion leading to a decreased fusion barrier is the likely cause of this phenomenon. In addition to this systematic study, the lightest isotope of element 107, bohrium, was discovered in the 209Bi(52Cr,n) reaction. 260Bh was found to decay by emission of a 10.16 MeV alpha particle with a half-life of 35 ms. The cross section is 59 pb at an excitation energy of 15.0 MeV. The effect of the N = 152 shell is also seen in this isotope's alpha particle energy, the first evidence of such an effect in Bh. All reactions studied are also compared to model predictions by Swiatecki, Siwek-Wilcznska, and Wilczynski's 'Fusion By Diffusion' theory

  1. 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

  2. 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