HFB fission properties
The present tables contain the predictions of the fission properties [1] obtained within the Hartree-Fock-Bogolyubov approach based on the BSk14 Skyrme force [2], which has proven its capacity to estimate the static fission barrier height with a relatively high degree of accuracy. In particular, the barriers determined from the present HFB-14 fission path reproduce the 52 primary empirical barriers (i.e the highest barriers) of nuclei with 88 ≤ Z ≤ 96 (which are always less than 9 MeV high) with an rms deviation as low as 0.67 MeV. A similar accuracy is obtained (0.65 MeV) for the secondary barriers.
Fission properties are provided for about 1000 nuclei with 90 ≤ Z ≤ 110 lying between the valley of beta-stability and the neutron drip line. Such properties include
o The static 1-dimensional fission path, i.e the most gently climbing or steepest descending path found and projected along the quadrupole deformation parameter b2. The energy along the path is estimated relative to the ground-state energy.
| Z=90 | Z=91 | Z=92 | Z=93 | Z=94 | Z=95 | Z=96 |
| Z=97 | Z=98 | Z=99 | Z=100 | Z=101 | Z=102 | Z=103 |
| Z=104 | Z=105 | Z=106 | Z=107 | Z=108 | Z=109 | Z=110 |
o The barrier heights, barrier widths (assuming an equivalent inverted parabola) and the deformation parameters (quadrupole, octupole and hexadecapole) of the (maximum 3) saddle points and (maximum 2) shape isomers lying along the fission path. The saddle points are ordered by decreasing heights. The corresponding table can be found here
o The Nuclear Level Densities (NLD) obtained within the combinatorial model of Ref. [3], based on the single-particle scheme and pairing properties obtained coherently with the same HFB-14 model constrained at each of the 2 (or 3) saddle points or of the 1 (or 2) shape isomer deformations. The NLD are given in table format (in a energy, spin and parity grid identical to the ground-state level density). The NLD are provided for about 1000 nuclei with 90 ≤ Z ≤ 110 lying between the valley of beta-stability and the neutron drip line.
Note that the second and third saddles as well as the second minimum are always found to be left-right asymmetric within the HFB framework. For these reasons, the tabulated NLD have already been multiplied by a factor 2. In contrast, the inner barrier and minimum could be triaxial (though it has been estimated within the approximation of an axial symmetry) and in this case, it needs to be multiplied by the corresponding enhancement factor [3,4].
The HFB-14 fission properties have been used consistently in the estimate of neutron-induced fission cross sections and compared with experimental data [1]. The corresponding photo-, neutron-, proton-, and alpha-induced fission rates calculated on the basis of the TALYS code are available HERE.
REFERENCES:
[1] S. Goriely, S. Hilaire, A.J. Koning, S. Sin, R. Capote, 2009, Physics Review C79, 024612
[2] S. Goriely, M. Samyn, J.M. Pearson, 2007, Physical Review C75, 064312
[3] S. Goriely, S. Hilaire, A.J. Koning, 2008, Physical Review C78, 064307
[4] RIPL-3 Handbook “Parameters for Calculation of Nuclear Reactions of Relevance to Non-Energy Nuclear Applications”, 2009, IAEA-Tecdoc, in press, also available at http://www-nds.iaea.org/RIPL-3/
(Last update 01/01/2009)