Conveners
14 Experiments in nuclear astrophysics IV
- Shigeru Kubono (CNS, University of Tokyo)
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Michael Heil (Forschungszentrum Karlsruhe, Institut f\"ur Kernphysik)30/06/2006, 08:30Experiments in nuclear astrophysicsInvitedThe neutron time of flight (n\_TOF) facility at CERN is a neutron spallation source with a flight path of 187 m. A proton beam from the CERN PS with an energy of 20 GeV, an intensity of $7 \times 10^{12}$ protons/pulse and a pulse width of 6 ns is focused on a lead spallation module. A white neutron beam is produced which covers fully the energy range of interest for capture cross...Go to contribution page
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Mariko Segawa (Research Center for Nuclear Physics, Osaka University, Japan)30/06/2006, 09:00Experiments in nuclear astrophysicsOral contribution187Re-187Os pair is known as the most promising nuclear cosmochronometer with considerable potential. This is because 187Re beta decays with the half-life of 42.3+/- 1.3 Gyr,187Re is produced only by the rapid neutron capture process nucleosynthesis, and both 186Os and 188Os are produced only by the slow neutron capture process nucleosynthesis. However, there remains a non-trivial...Go to contribution page
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Marita Mosconi (Forschungszentrum Karlsruhe GmbH (FZK))30/06/2006, 09:15Experiments in nuclear astrophysicsOral contributionThe stellar neutron capture cross sections of 186Os and 187Os are fundamental for the Re/Os cosmo-chronometer for defining the s-process abundance of 187Os. Subtraction of the s component from the solar 187Os abundance yields the radiogenic contribution to 187Os due to the beta-decay of 187Re (t1/2=42.3 Gy) since the onset of r-process nucleosynthesis. The laboratory cross section of...Go to contribution page
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A.R. Junghans (Institut für Kern- und Hadronenphysik Forschungszentrum Rossendorf)30/06/2006, 09:30Experiments in nuclear astrophysicsOral contributionIn explosive nucleosynthesis temperatures are high enough for photo dissociation reaction to occur, e.g. leading to the production of p-process nuclei. In order to understand the details of element production and element disruption we started an experimental program at the new bremsstrahlung facility of the superconducting electron accelerator ELBE of FZ-Rossendorf, Dresden. The...Go to contribution page
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Sebastian Müller (Institut fuer Kernphysik, TU Darmstadt)30/06/2006, 09:45Experiments in nuclear astrophysicsOral contributionPhotodissociation cross sections play an important role in our understanding of nucleosynthesis in the mass region above A > 60. The bulk of these heavy nuclei is produced by neutron capture reactions during the s- and r-process. The so-called branching points of the s-process have typical half-lives of the order of a few days up to a few hundred years. The direct measurement of neutron...Go to contribution page
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S Goko (Konan University)30/06/2006, 10:00Experiments in nuclear astrophysicsOral contributionPhotoneutron cross sections for $^{180}$Ta$^{m}$ were determined from simultaneous measurements of total cross sections ($\sigma^{tot}$) and ground-state cross sections ($\sigma^{gs}$) for $^{180}$Ta in photodisintegration of $^{181}$Ta with laser Compton-backscattered $\gamma$ rays. Techniques of direct neutron counting and photoactivation were used for the measurement of...Go to contribution page
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Dr Cesar Domingo Pardo (Instituto de Fisica Corpuscular (IFIC) UV-CSIC)30/06/2006, 10:15Experiments in nuclear astrophysicsOral contributionResonance cross sections relevant for the termination of the s-process reaction path have been determined for 204,206,207Pb and 209Bi at the CERN neutron time-of-flight spectrometer n_TOF. The measurements were carried out in the neutron energy range from 1 eV up to 500 keV. By using a system of C6D6-detectors with optimized neutron sensitivity, the main corrections of previous...Go to contribution page