Conveners
14 Experiments in nuclear astrophysics IV
- Shigeru Kubono (CNS, University of Tokyo)
Michael Heil
(Forschungszentrum Karlsruhe, Institut f\"ur Kernphysik)
30/06/2006, 08:30
Experiments in nuclear astrophysics
Invited
The 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...
Mariko Segawa
(Research Center for Nuclear Physics, Osaka University, Japan)
30/06/2006, 09:00
Experiments in nuclear astrophysics
Oral contribution
187Re-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...
Marita Mosconi
(Forschungszentrum Karlsruhe GmbH (FZK))
30/06/2006, 09:15
Experiments in nuclear astrophysics
Oral contribution
The 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...
A.R. Junghans
(Institut für Kern- und Hadronenphysik Forschungszentrum Rossendorf)
30/06/2006, 09:30
Experiments in nuclear astrophysics
Oral contribution
In 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...
Sebastian Müller
(Institut fuer Kernphysik, TU Darmstadt)
30/06/2006, 09:45
Experiments in nuclear astrophysics
Oral contribution
Photodissociation 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...
S Goko
(Konan University)
30/06/2006, 10:00
Experiments in nuclear astrophysics
Oral contribution
Photoneutron 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...
Dr
Cesar Domingo Pardo
(Instituto de Fisica Corpuscular (IFIC) UV-CSIC)
30/06/2006, 10:15
Experiments in nuclear astrophysics
Oral contribution
Resonance 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...
