Developments in the Calculation of Fission
Potential-Energy Surfaces
Peter Möller, David G. Madland, and Arnold J. Sierk
Theoretical Division, Los Alamos National Laboratory, New Mexico 87545, USA
Akira Iwamoto
Advanced Science Research Center,
Japan Atomic Energy Research Institute,
Tokai, Naka-gun, Ibaraki, 319-11 Japan
This paper was presented at the
ND2001, International Conference on Nuclear Data for Science
and Technology, Tsukuba, Ibaraki, Japan, October 7-12, 2001.
It has been assigned
Los Alamos National Laboratory Preprint No LA-UR-01-4851,
Abstract:
We present calculations based on a realistic theoretical model of the
multi-dimensional potential-energy surface of a fissioning nucleus. This
surface
guides the nuclear shape evolution from the ground state, over inner and outer
saddle points, to the final configurations of separated fission fragments.
Until recently, no calculation has properly explored a shape parameterization of
sufficient dimensionality to permit the corresponding potential-energy surface
to exhibit the multiple minima, valleys, saddle points and ridges that
correspond to characteristic observables of the fission process. Here we
calculate and analyze five-dimensional potential-energy landscapes based on
grids of several million deformation points. We find that
observed fission features such as different energy thresholds for symmetric and
asymmetric fission and fission-fragment mass and kinetic-energy distributions
are very closely related to properties of the valleys and mountain passes
present in the calculated five-dimensional energy landscapes. We have also
determined fission-barrier heights for 31 nuclei throughout the periodic
system.
Figures 3, 4, and 5, are in color, so the paper should be printed
on a color printer. Figure 4 is quite large, about 20 Mb,
and and occurs on page 4. On some printers
these pages may take a considerable time to print.
The complete manuscript in color
is
available for download.
A black-and-white version
is also
available for download.
Peter Moller
Last modified: Tue Sep 25 10:07:22 MDT 2007