Deduced soft-rotator model Hamiltonian parameters and collective properties of medium-to-heavy even-even nuclei

Kunieda, Satoshi; Chiba, Satoshi; Shibata, Keiichi; Ichihara, Akira; Iwamoto, Osamu; Iwamoto, Nobuyuki; Fukahori, Tokio; Sukhovitskij, E.*

JAEA-Research 2010-053, 59 Pages, 2011/02

JAEA-Research-2010-053.pdf:1.24MB

The soft-rotator model Hamiltonian parameters were deduced for 63 even-even medium and heavy nuclei in a mass range . We obtained those values by the combination of the low-lying level structure and the coupled-channels proton scattering analyses. It was found that the values of the effective quadrupole and octupole deformations obtained were consistent with those derived from experimental data. Besides, the equilibrium ground-state quadrupole deformation parameters were also in reasonable accord with the theoretical mass-models results for deformed heavy nuclei. In this report, we present a complete set of the Hamiltonian parameters for each nucleus. The obtained values of the parameters often varied with the constituent neutron and/or proton numbers anomalously. On the other hand, some clear systematic trends were seen among the major Hamiltonian parameters.

Systematical nucleon-induced optical model analysis for medium and heavy nuclei with coupled-channel framework

Kunieda, Satoshi; Chiba, Satoshi; Shibata, Keiichi; Ichihara, Akira; Sukhovitskij, E.*

Proceedings of International Conference on Nuclear Data for Science and Technology (ND 2007), Vol.1, p.227 - 230, 2008/05

The optical model analyses were carried out for nucleon-induced reactions on medium and heavy nuclei from 1 keV to 200 MeV. The coupled-channels method based on the rigid-rotator model was employed as an initial approach. It was found that the coupled-channels analyses were indispensable to obtain a global formulation of optical potential. In addition to this, the coupled-channels calculations based on the soft-rotator model was applied to analyses for various even-even fission product isotopes. They reproduced measured cross sections better than the rigid-rotator model in many cases. Though the latter is our ongoing study, we show the advantage of coupled-channels calculations and the applicability of the soft-rotator model in this conference.

Coupled-channels analysis of nucleon interaction data of Si up to 200 MeV based on the soft rotator model

Sun, W.*; Watanabe, Yukinobu*; Sukhovitskij, E.*; Iwamoto, Osamu; Chiba, Satoshi

Journal of Nuclear Science and Technology, 40(9), p.635 - 643, 2003/09

https://doi.org/10.3327/jnst.40.635

A consistent analysis for nuclear level structure and nucleon scattering data up to 200 MeV were performed for sd-shell nuclei, Si, using a unified framework of soft-rotator model and coupled-channels approach. The soft-rotator model parameters and optical model parameters were derived. The calculations showed good agreement with experimental data for both collective level and nucleon interaction data -- neutron total cross sections, proton reaction cross sections, and nucleon scattering angular distributions.

Nuclear level structure, B(E2) -transitions and nucleon interaction data for Fe by a unified soft-rotator model and coupled-channels framework

Sukhovitskij, E.*; Chiba, Satoshi; Lee, J.*; Lee, Y.*; Chang, J.*; Maruyama, Toshiki; Iwamoto, Osamu

Journal of Nuclear Science and Technology, 39(8), p.816 - 826, 2002/08

https://doi.org/10.3327/jnst.39.816

The soft-rotator model (SRM) and a coupled-channels method based on the oupling scheme based on the wave functions of the SRM were applied for a self-consistent analyses of the nuclear level structure, B(E2) and the nucleon interaction data of Fe. The model could describe the experimental collective levels of Fe up to the excitation energy of 5.5 MeV successfully. Relativistic kinematics and global optical potential form, consistent with the shell model, dispersion relationship and Dirac phenomenology, were used in coupled-channels optical model approach to overcome problems left in our previous work. The available nucleon interaction experimental data up to 160 MeV and B(E2) - transitions were described satisfactorily.