Predicting the optical observables for nucleon scattering on even-even actinides  

作　　者：D. S. Martyanov E. Sh. Soukhovitskii R. Capote J. M. Quesada S. Chiba 

机构地区：[1]Joint Institute for Energy and Nuclear Research, 220109, Minsk-Sosny, Belarus [2]NAPC-Nuclear Data Section, International Atomic Energy Agency, Vienna A-1400, Austria [3]Departamento de Fisica Atomica, Molecular y Nuclear, Universidad de Seviha, Ap.1065, E-4i080 Sevilla, Spain [4]Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology 2-12-1-N1-90okuyama, Meguro-ku, Tokyo 152-8550, Japan

出　　处：《Chinese Physics C》2017年第9期123-128,共6页中国物理C（英文版）

基　　金：Supported by International Atomic Energy Agency,through the IAEA Research Contract 19263;the Spanish Ministry of Economy and Competitivity under Contracts FPA2014-53290-C2-2-P and FPA2016-77689-C2-1-R

摘　　要：The previously derived Lane consistent dispersive coupled-channel optical model for nucleon scattering on 232Th and 23Su nuclei is extended to describe scattering on even-even actinides with Z=90-98. A soft-rotator- model （SRM） description of the low-lying nuclear structure is used, where the SRM Hamiltonian parameters are adjusted to the observed collective levels of the target nucleus. SRM nuclear wave functions （mixed in K quantum number） have been used to calculate the coupling matrix elements of the generalized optical model. The ＂effective＂ deformations that define inter-band couplings are derived from the SRM Hamiltonian parameters. Conservation of nuclear volume is enforced by introducing a dynamic monopolar term to the deformed potential, leading to additional couplings between rotational bands. The fitted static deformation parameters are in very good agreement with those derived by Wang and collaborators using the Weizs^cker-Skyrme global mass model （WS4）, allowing use of the latter to predict cross sections for nuclei without experimental data. A good description of the scarce ＂optical＇experimental database is achieved. SRM couplings and volume conservation allow a precise calculation of the compound-nucleus formation cross sections, which is significantly different from that calculated with rigid-rotor potentials coupling the ground-state rotational band. The derived parameters can be used to describe both neutron- and proton-induced reactions.The previously derived Lane consistent dispersive coupled-channel optical model for nucleon scattering on 232Th and 23Su nuclei is extended to describe scattering on even-even actinides with Z=90-98. A soft-rotator- model （SRM） description of the low-lying nuclear structure is used, where the SRM Hamiltonian parameters are adjusted to the observed collective levels of the target nucleus. SRM nuclear wave functions （mixed in K quantum number） have been used to calculate the coupling matrix elements of the generalized optical model. The ＂effective＂ deformations that define inter-band couplings are derived from the SRM Hamiltonian parameters. Conservation of nuclear volume is enforced by introducing a dynamic monopolar term to the deformed potential, leading to additional couplings between rotational bands. The fitted static deformation parameters are in very good agreement with those derived by Wang and collaborators using the Weizs^cker-Skyrme global mass model （WS4）, allowing use of the latter to predict cross sections for nuclei without experimental data. A good description of the scarce ＂optical＇experimental database is achieved. SRM couplings and volume conservation allow a precise calculation of the compound-nucleus formation cross sections, which is significantly different from that calculated with rigid-rotor potentials coupling the ground-state rotational band. The derived parameters can be used to describe both neutron- and proton-induced reactions.

关 键 词：optical model soft-rotator model FRDM deformations WS4 deformations even-even actinides 

分 类 号：O571[理学—粒子物理与原子核物理]