Workshop on the Origin of the Heavy Elements - Astrophysical Models

290 Pages·1999·15.329 MB·English

LA-13686-C
Confuence
Issued: ]anuay 2000 , ~
Workshop on the Origz”nof the “
Heavy Elements: Astrophysical Models
and Experimen~al Challenges
Santa Fe, New Mexico
%ptembi?r 34,1999
Edited by
Robert C. Haight
John L. Ullmann
Daniel D. Stro&nan
Paul E. Koehler*
Franz Kaeppeler**
*LaboratoyAjWte atLosAhnos.PhysicsDivision,OakRidgeNationalLaboratory,
Bldg.6010,MS6354,OakRidge,TN 37831-6354
**[email protected],K Bau425,D-76021,
Pos~ach3640,Kdsruhe, Germany
Los Alamos
NATIONAL LABORATORY
LosAlamosN,ewMexico87545
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Workshop on the Origin of the Heavy Elements:
Astrophysical Models and Experimental Challenges
Edited by
R. C. Haight, J. L. Ullmann, D. D. Strottman
LosAlamosNationalLaboratory
.’
P. E. Koehler
OakRidgeNationalLaboratory
and
F. Kaeppeler ,,.,
Forschungszentrum Karlsruhe ,,-
ABSTRACT
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This Workshop was held on September 3-4, 1999,following the 10th
International Symposium on Capture Gamma-RaySpectroscopy.
Presentations were made by 14speakers, 6 from the US and 8 horn other
countries on topics relevant to s-, r- and rp-process nucleosynthesis.
Laboratory experiments, both present and planned, and astrophysical
observations were represented as were astrophysical models.
Approximately 50 scientistsparticipated inthis Workshop. These
Proceedings consist of copies of vu-graphs presented at the Workshop.
For iirther ~ormation, the interested readers are referred to the authors.
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Workshop on the Origin of the Heavy Elements:
Astrophysical Models and Experimental Challenges
Schedule
Friday, September 3
1:50-2:00 Welcome
r-process Nucleosynthesis
2:00-2:30 Peter Moller Nuclear Mass Models: Past Achievements,
Current Status, and Future Challenges
2:30-3:00 Stephen A. Becker Approximating the r-process on Earth with
Thermonuclear Explosions
3:00-3:30 Stephane Goriely Uncertainties inthe Th Cosmochronolofg
3:30-4:00 Discussion on the r-process with refreshments
4:00-4:30 l?aolo Mutd . Neutron Capture Cross Sections of Kr-84
and Kr-86 and Their Impact on Stellar
Nucleosynthesis
Proton-rich Nuclides .
4:30-5:00 Paul Kienle Half-lives ofrp-process WaitingPoint Nuclei
5:00-5:30 H. H. Pitz Photoactivation of 180mTa and Implications
for the Nucleosynthesis ofNature’s Rarest
Stable Isotope
5:30-7:00 Discussion ofproton-rich nuclei with refieshents -
Continued (next page)
Workshop Schedule (continued)
Saturday, September 4
Astronomical Observations and Models
8:30-9:00 A. Mengoni Structure and EM Dissociation of 9Be
9:00-9:30 Joyce Ann Guzik Sensitivity of Solar Oscillation Frequencies
to Element Abundances and Composition
Gradients
9:30-10:00 CorinueNeuforge Linking Field Metal-Poor Stars and Globuk
Clusters
10:00-10:30 Hideo Harada Thermal Neutron Capture Cross Sections
and Resonance Integrals of Fission Products
10:30-11:00 Break and Discussion
New Capabilities and Plans
11:00-11:30 0. Shcherbakov Neutron Time-of-flight Sepctrometer GNEIS
at the l-GeV Proton Synchrotronsof PNPI
11:30-12:00 Rene Reifhrth The Use of 4pi Detectors at Spallation
Neutron Sources
12:00-12:30 Paul Koehler Plans for Measurements at Oak Ridge
12:30-1:00 Working Lunch –
1:00-1:30 Robert Rundberg Plans for Measurements at Los Alamos
Nuclear Mass Models: Past Achievements, Current
Status and Challenges
Future
Peter M611er
Theoretical Division, Los AlamosNational”Laboratoq, Los Alamos, Nil! 87545
The history of mass models is briefly dkcussed. Features of some commonlyused
mass models, such as those developed by Liran%eldes, von Groot~Hilf, Pearson-Tondeur,
Myers-Swiatecki, and M611er-Nixare compared and discussed.
. We particularly discuss how the models behave when applied to masses outside the
region to which parameters were adjusted, that is how reliably the models behave in
regions close to the tilp lines ahd in the superheavy-element region.
We discuss the deviations that remain between model results and experimental data,
and what physical effects need be more realistically described to remove such deviations
so that greater model accuracies may be obtained.
Our latest manuscripts and mass tables are available from URL
http: //t2.lanl.gov
and various Iiis horn this U~L.
For data related to the M611er-Nixmass model the URL is: .
http://t2.lanl.gov/data/astro/motix96/moWx.html “
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Macroscopic-microscopic model:
Q Macroscopic models: Liquid-drop, droplet, finite-range
liquid-drop and finite-range droplet models.
b Microscopic models: Nilsson modified oscillator, two-
center oscillator, Woods-Saxon and folded-Yukawa
single-particle potentials.
~ For each model several parameter sets.
For progress it k necessary to proceed in a consistent man-
ner with a clear strategy of model development.