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We study the cluster emission properties of 224 Ra and 238 Pu employing the Barcelona-Catania-Paris-Madrid (BCPM) energy density functional (EDF). Starting from two-dimensional potential energy surfaces, coexisting fission paths are identified. A fission valley located at large octupole deformations, corresponding to a highly-asymmetric mass distribution, is found in both nuclei. As the corresponding fragments are dominated by the presence of 208 Pb, we can relate this fission path to the emergence of cluster emission. Using the octupole moment as collective degree of freedom, we compute the cluster decay half-lives and study the impact of collective inertias, pairing strength and collective zero-point energy. The agreement with experimental data resembles the results obtained for spontaneous fission half-lives, indicating the capability of BCPM to consistently describe a large variety of fission phenomena, including cluster emission. [ABSTRACT FROM AUTHOR]

A simple collective model for description of the effect of the alpha-cluster degree of freedom in the structure of heavy and superheavy nuclei is suggested. The alpha-chains of nuclei based on some of the Pb isotopes are considered. It is shown based on the experimental data on nuclear binding energies that the effect of the strong coupling of the alpha-mode and the octupole correlations in Rn, Ra, Th and U isotopes is manifested. The excited states associated with the alpha-cluster degree of freedom are considered and their excitation energies are estimated as being larger than 1.7 MeV. This corresponds to α -decay probability from the ground state to these states 4–7 orders of magnitude less than α -decay between the ground states. Although, their structure is determined by the same dynamical variable as the structure of the ground states. [ABSTRACT FROM AUTHOR]

The half-lives of alpha decays for even-even nuclei with Z = 60 − 118 and the cluster radioactivities for even-even emitters for which the experimental data are available, also the various cluster decays of even-even radium isotopes are calculated. Our calculations are within the framework of Wentzel-Kramers-Brillouin (WKB) method by considering the Bohr-Sommerfeld quantization condition based on the shifted Deng-Fan potential. The obtained results are compared with the squared Woods-Saxon and Cosh potentials and several theoretical models, including the universal model (UNIV), the unified fission model (UFM), the universal decay law (UDL), and Ni, Royer, Tavares and Balasubramaniam semiempirical formulas, as well as the experimental data. Good agreement between the experimental and the proposed potential model results, indicates that the shifted Deng-Fan potential is a suitable phenomenological potential to describe both alpha and cluster decays of radioactive nuclei. Also we observe the significant role of neutron magicity in the half-lives of cluster decays of radium isotopes at N = 126 of daughter nuclei and the parent nucleus 214Ra. [ABSTRACT FROM AUTHOR]