Fission Barriers at the End of the Chart of the Nuclides

P. MÖLLER and A. J. SIERK
Theoretical Division, Los Alamos National Laboratory, New Mexico 87545, USA

T. ICHIKAWA
Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502, Japan

A. IWAMOTO
Advanced Science Research Center, Japan Atomic Energy Agency (JAEA), Tokai-mura, Naka-gun, Ibaraki, 319-1195, Japan

M. MUMPOWER
Joint Institute for Nuclear Astrophysics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556, USA

Phys. Rev. C 91 (2015) 024310
It has been assigned Los Alamos National Laboratory Preprint No LA-UR-15-24999.



Abstract:

We present calculated fission-barrier heights for 5239 nuclides, for all nuclei between the proton and neutron drip lines with 171 ≤ A ≤ 330. The barriers are calculated in the macroscopic-microscopic finite-range liquid-drop model (FRLDM) with a 2002 set of macroscopic-model parameters. The saddle-point energies are determined from potential-energy surfaces based on more than five million different shapes, defined by five deformation parameters in the three-quadratic-surface shape parameterization: elongation, neck diameter, left-fragment spheroidal deformation, right-fragment spheroidal deformation, and nascent-fragment mass asymmetry. The energy of the ground state is determined by calculating the lowest-energy configuration in both the Nilsson perturbed-spheroid (ε) and in the spherical-harmonic (β) parameterizations, including axially asymmetric deformations. The lower of the two results (correcting for zero-point motion) is defined as the ground-state energy. The effect of axial asymmetry on the inner barrier peak is calculated in the (ε,γ) parameterization. We have earlier benchmarked our calculated barrier heights to experimentally extracted barrier parameters and found average agreement to about one MeV for known data across the nuclear chart. Here we do additional benchmarks and investigate the qualitative, and when possible, quantitative agreement and/or consistency with data on β-delayed fission, isotope generation along prompt-neutron-capture chains in nuclear-weapons tests, and superheavy-element stability. These studies all indicate that the model is realistic at considerable distances in Z and N from the region of nuclei where its parameters were determined.

The complete manuscript in color is available for download.

The barrier table onebar-forprc , in computer-readable format, is available for download.
The format is (3I5,F10.3)
The variables are proton number, neutron number, nucleon number, and barrier height.

We provide the 10 figures as individual .eps.gz and .pdf files files:

Figure Fig01-moller-bar.eps.gz in format .eps.gz and Fig01-moller-bar.pdf in .pdf format is available for download.
Figure Fig02-moller-bar.eps.gz in format .eps.gz and Fig02-moller-bar.pdf in .pdf format is available for download.
Figure Fig03-moller-bar.eps.gz in format .eps.gz and Fig03-moller-bar.pdf in .pdf format is available for download.
Figure Fig04-moller-bar.eps.gz in format .eps.gz and Fig04-moller-bar.pdf in .pdf format is available for download.
Figure Fig05-moller-bar.eps.gz in format .eps.gz and Fig05-moller-bar.pdf in .pdf format is available for download.
Figure Fig06-moller-bar.eps.gz in format .eps.gz and Fig06-moller-bar.pdf in .pdf format is available for download.
Figure Fig07-moller-bar.eps.gz in format .eps.gz and Fig07-moller-bar.pdf in .pdf format is available for download.
Figure Fig08-moller-bar.eps.gz in format .eps.gz and Fig08-moller-bar.pdf in .pdf format is available for download.
Figure Fig09-moller-bar.eps.gz in format .eps.gz and Fig09-moller-bar.pdf in .pdf format is available for download.
Figure Fig10-moller-bar.eps.gz in format .eps.gz and Fig10-moller-bar.pdf in .pdf format is available for download.
Peter Moller
Created: August 21 2014 --> Last modified: August 21 2015