Half-lives Of Cluster Radioactivity Research Articles

Systematic calculations on cluster radioactivity half-lives of trans-lead nuclei with effective liquid drop model

The cluster radioactivities of trans-lead nuclei are systematically investigated by using the effective liquid drop description with the varying mass asymmetry shape and effective inertial coefficient. An effective nuclear radius constant formula is used instead of the original empirical formula in calculation. The calculated half-lives are in good agreement with the available experimental data. The root-mean-square deviation between the calculated logarithmic half-lives and the experimental ones is only 0.895. From the plots of the calculated lgT1/2 values versus the neutron (or proton) number of daughter, the shell effect of neutron magic number N=126 (or proton magic number Z=82) can be clearly seen. The odd-even-stagger can be clearly seen in the odd clusters 25Ne, 29Mg. The calculated half-lives conform to the Geiger-Nuttall law. We obtain some important conclusions about the Geiger-Nuttall law from the calculated results.

Half-lives of cluster radioactivity with a generalized liquid-drop model

Half-lives of cluster radioactivity treated as a very asymmetric spontaneous fission are investigated within the WKB barrier-penetration probability. The potential barrier is constructed using a generalized liquid-drop model (GLDM), taking into account the nuclear proximity energy, the mass asymmetry, an accurate nuclear radius, a phenomenological pairing correction and the microscopic shell corrections. The calculated cluster emission half-lives accurately reproduce the experimental data. Predictions are provided for possible cluster radioactivity within the GLDM using the up-to-date atomic mass table AME2011, which may be used for the future experiments.

Systematic calculations on cluster radioactivity half-lives

Half-lives of cluster radioactivity have been systematically investigated using the effective liquid drop description with the varying mass asymmetry shape and effective inertial coefficient. A new nuclear radius formula including the isospin-dependent term is presented instead of the old empirical radius formula Rp = 1.20A1/3p. The calculated half-lives with the new nuclear radius formula are in good agreement with the available experimental data and closer to the experimental values than the ones with the old nuclear radius formula. We made some predictions on the new possible island of cluster radioactivity around the double-magic daughter nucleus 100Sn. The calculated results show that the α-like-nuclei clusters are the most probable cases for measurements in this region. We also try to find cluster radioactivities around another double-magic daughter nucleus 132Sn, but there is no clear evidence for the existence of cluster radioactivity. The predictions on the half-lives of cluster radioactivity around the daughter nucleus 208Pb are made as well. These results may be useful for future experiments.

HALF-LIVES OF CLUSTER RADIOACTIVITY OF HEAVY NUCLEI

The half-lives of cluster radioactivity (14C-34Si) are well reproduced by a new formula between half-lives and decay energies. This formula is a natural extension of both the Geiger-Nuttall law and the Viola-Seaborg formula from α-decay to cluster radioactivity. The half-lives of new cluster emitters are predicted based on this formula. These are useful for future experimental researches of cluster radioactivity. The physics related to this formula is analyzed and discussed.

New perspective on complex cluster radioactivity of heavy nuclei

Experimental data of complex cluster radioactivity $(^{14}\mathrm{C}\text{--}^{34}\mathrm{Si})$ are systematically analyzed and investigated with different models. The half-lives of cluster radioactivity are well reproduced by a new formula between half-lives and decay energies and by a microscopic density-dependent cluster model with the renormalized M3Y nucleon-nucleon interaction. The formula can be considered as a natural extension of both the Geiger-Nuttall law and the Viola-Seaborg formula from simple $\ensuremath{\alpha}$ decay to complex cluster radioactivity where different kinds of clusters are emitted. It is useful for experimentalists to analyze the data of cluster radioactivity. A new linear relationship between the decay energy of cluster radioactivity and the number of $\ensuremath{\alpha}$ particles in the cluster is found where the increase of decay energy for an extra $\ensuremath{\alpha}$ particle is between 15 and 17 MeV. The possible physics behind this new linear relationship is discussed.

Half-lives of cluster radioactivity within a model including superfluid phenomena and resonance effects.

A model is proposed for studying exotic cluster radioactivities. This model is general and realistic that one can test the actual main treatments of clustering and penetration phenomena in nuclear many-particle systems. A reliable and rather simple approximation derived in this model is found on the continuum hopping treatment of clustering and on an integral formalism of decay dynamics including resonance scattering effects. The half-life estimates are performed for experimentally detected cluster radioactivities and for the most interesting cases under the current experimental search.

Exact finite range DWBA calculations for heavy-ion induced nuclear reactions

Nuclear cluster radioactivity is investigated using microscopic potentials in the framework of the Wentzel–Kramers–Brillouin approximation of quantum tunneling by considering the Bohr–Sommerfeld quantization condition. The microscopic cluster–daughter potential is numerically constructed in the well-established double-folding model. A realistic M3Y-Paris NN interaction with the finite-range exchange part as well as the ordinary zero-range exchange NN force is considered in the present work. The influence of nuclear deformations on the cluster decay half-lives is investigated. Based on the available experimental data, the cluster preformation factors are extracted from the calculated and the measured half lives of cluster radioactivity. Some useful predictions of cluster emission half-lives are made for emissions of known clusters from possible candidates, which may guide future experiments.