Bulg. J. Phys. vol.42 no.4 (2015), pp. 362-371



Fission Barriers of Two Odd-Neutron Heavy Nuclei

Meng-Hock Koh1-3, L. Bonneau2,3, T.V. Nhan Hao6,7, Dao Duy Duc4,5, P. Quentin1-4
1Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia
2Univ. Bordeaux, CENBG, UMR5797, 33170 Gradignan, France
3CNRS, IN2P3, CENBG, UMR5797, 33170 Gradignan, France
4Division of Nuclear Physics, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City, Vietnam
5aculty of Applied Sciences, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City, Vietnam
6Department of Physics, College of Education, Hue University, 34 Le Loi Street, Hue City, Vietnam
7Center for Theoretical and Computational Physics, College of Education, Hue University, 34 Le Loi Street, Hue City, Vietnam
Abstract. The fission barriers of two odd-neutron heavy odd nuclei,namely the 235U and 239Pu isotopes have been calculated within a self-consistent Hartree-Fock-plus-BCS approach with blocking. A Skyrme nucleon-nucleon effective interaction has been used together with a seniority force to describe pairing correlations. A full account of the genuine time-reversal symmetry breaking due to the presence of an unpaired nucleon has been incorporated at the mean field level. The SIII and SkM* parametrizations of the Skyrme interaction have been retained as well as for a part a newer parametrization, SLy5*. The seniority force parameters have been fitted to reproduce experimental odd-even mass differences in the actinide region. To assess the relevance of our calculated fission barrier distribution (as a function of the quantum numbers), we have studied the quality of our results with respect to the spectroscopy of band heads (for configurations deemed to be a pure single particle character) in the ground and fission isomeric states. Fission barriers of the considered odd nuclei have been compared with what is obtained for their even-even neighbouring isotopes (namely 234U and 236U, 238Pu and 240Pu respectively) to determine the so-called specialization energies. Various corrections and associated uncertainties have been discussed in order to compare our results with available data.

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