HFB fission properties

The present tables contain the predictions of the fission properties [1] obtained within the Hartree-Fock-Bogolyubov approach based on the BSkG3 energy density functional [1], which has proven its capacity to estimate the static fission barrier height with a high degree of accuracy. In particular, the barriers determined from the present BSkG3 fission path reproduce the 45 primary empirical barriers [3] (i.e the highest barriers) of nuclei with 90 ≤ Z ≤ 96 with an rms deviation as low as 0.33 MeV. An accuracy of 0.6 MeV is obtained for the secondary barriers.

Fission properties are provided for about 2000 nuclei with 90 ≤ Z ≤ 110 lying between the valley of beta-stability and the neutron drip line [3]. Such properties include

o The static 1-dimensional least-action path projected along the quadrupole deformation parameter b20. The energy along the path is estimated relative to the ground-state energy.

Z=90Z=91Z=92Z=93Z=94Z=95Z=96
Z=97Z=98Z=99Z=100Z=101Z=102Z=103
Z=104Z=105Z=106Z=107Z=108Z=109Z=110

o The barrier heights, barrier widths (assuming an equivalent inverted parabola) and the deformation parameters of the (maximum 3) saddle points and (maximum 2) shape isomers lying along the fission path. 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 BSkG3 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 2000 nuclei with 90 ≤ Z ≤ 110 lying between the valley of beta-stability and the neutron drip line.

First SaddleSecond SaddleThird saddleFirst isomerSecond Isomer
Z=90Z=90Z=90Z=90Z=90
Z=91Z=91Z=91Z=91Z=91
Z=92Z=92Z=92Z=92Z=92
Z=93Z=93Z=93Z=93Z=93
Z=94Z=94Z=94Z=94Z=94
Z=95Z=95Z=95Z=95Z=95
Z=96Z=96Z=96Z=96Z=96
Z=97Z=97Z=97Z=97Z=97
Z=98Z=98Z=98Z=98Z=98
Z=99Z=99Z=99Z=99Z=99
Z=100Z=100Z=100Z=100Z=100
Z=101Z=101Z=101Z=101Z=101
Z=102Z=102Z=102Z=102Z=102
Z=103Z=103Z=103Z=103Z=103
Z=104Z=104Z=104Z=104Z=104
Z=105Z=105Z=105Z=105Z=105
Z=106Z=106Z=106Z=106Z=106
Z=107Z=107Z=107Z=107Z=107
Z=108Z=108Z=108Z=108Z=108
Z=109Z=109Z=109Z=109Z=109
Z=110Z=110Z=110Z=110Z=110

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 BSkG3 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] G. Grams, W. Ryssens, G. Scamps, S. Goriely, N. Chamel, Eur. Phys. J. A59, 270 (2023)

[2] A. Sanchez Fernandez, W. Ryssens, G. Grams, S. Goriely, Eur. Phys. J. A (2026)

[3] 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 01/12/2025)