| Terascale
Supernova Initiative
The Terascale Supernova Initiative is a multidisciplinary collaboration
to develop models for core-collapse supernovae and enabling
technologies in radiation transport, radiation hydrodynamics,
nuclear structure, linear systems and eigenvalue solution, and
collaborative visualization. (See also the SciDAC
Supernova Science Center)
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| Figure
18 Energy expectation value E
= <H> as a function of temperature T
for selected A = 56 isobars. |
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An essential part of the nuclear equation of state in computer
simulations of core-collapse supernovae is the symmetry energy,
which describes the energy needed to separate protons and
neutrons. Symmetry energy is important because the dynamical
evolution of the collapse is strongly influenced by electron
captures on nuclei and free protons. Dean et al. performed
large-scale shell model Monte Carlo calculations for many
nuclei in the mass range A = 56–65 using an
effective quadrupole–quadrupole+pairing residual interaction.
Their main focus was the temperature dependence of the symmetry
energy, which they determined from the energy differences
between various isobaric pairs with the same pairing structure
and at different temperatures (Figure 18). They found that
the symmetry energy increases slightly when the temperature
is increased from 0.33 MeV to 1.23 MeV.
INVESTIGATORS
A. Mezzacappa, D. J. Dean, M. Strayer, and R. Toedte, Oak
Ridge National Laboratory;
J. Dongarra and V. Eijkhout, University of Tennessee, Knoxville;
D. Swesty, J. Lattimer, and M. Prakash, State University of
New York, Stony Brook; P. Saylor, F. Saied, and P. Baker,
University of Illnois; J. Hayes and G. Fuller, University
of California, San Diego; W. Haxton, University of Washington;
J. Blondin, North Carolina State University; B. Meyer, Clemson
University; S. Bruenn, Florida Atlantic University.
PUBLICATION
D. J. Dean, K. Langanke, and J. M. Sampaio, “Temperature
dependence of the symmetry energy,” Phys. Rev. C 66,
045802 (2002).
URL
http://www.phy.ornl.gov/tsi/ |
