Properties Of Superheavy Nuclei Research Articles

Structure and Properties of Super-heavy Nuclei in the Work of Adam Sobiczewski and His Collaborators

Structure and Properties of Super-heavy Nuclei in the Work of Adam Sobiczewski and His Collaborators

Properties of Super-heavy Nuclei and Search for Element 120

Properties of Super-heavy Nuclei and Search for Element 120

Alpha decay properties of heavy and superheavy elements

Analysing accurately the lifetimes of α-decay chains is an important tool to detect and study the properties of superheavy nuclei. 48Ca is used in the synthesis of superheavy nuclei Z = 106−118 at Dubna. The experimental work of 48Ca projectiles at Dubna has given an opportunity to study the superheavy element (SHE). Here, the α-decay properties for Z = 106–118 are evaluated using our CYE model and are compared with the available experimental and theoretical values.

Possibilities for synthesis of new isotopes of superheavy elements in fusion reactions

Background. In the ``cold'' fusion reactions based on the use of lead and bismuth targets, the proton-rich isotopes of superheavy (SH) elements up to $Z=113$ have been produced. More neutron-rich isotopes of SH elements (up to $Z=118$) have been synthesized in ``hotter'' fusion reactions of ${}^{48}$Ca with actinide targets. $\ensuremath{\alpha}$-decay half-lives of different isotopes of the same SH elements (for example, 112) were found to vary by several orders of magnitude. This indicates strong shell effects in this area of the nuclear map. The understanding of these effects and other properties of SH nuclei is strongly impeded by the absence of experimental data on decay properties of the not-yet-synthesized isotopes of SH elements located between those produced in the ``cold'' fusion reactions and those produced in the ``hot'' fusion reactions and also by the yet missing neutron-enriched isotopes of these elements.Purpose. In this paper we search for the optimal fusion reactions which may be used to fill this gap of the nuclear map and significantly extend the area of known SH nuclei.Method. For the calculation of the cross sections we use the same approach which was employed earlier for successful predictions of all ${}^{48}$Ca induced fusion reactions.Results. Several fusion reactions of the stable projectiles ${}^{40}$Ar, ${}^{44}$Ca, and ${}^{48}$Ca with different isotopes of actinides (lighter and heavier than those that have been already utilized in the Dubna experiments) could be used for synthesis of new SH nuclei. Predicted cross sections for the production of new isotopes of SH nuclei were found to be quite large, and the corresponding experiments can be easily performed at existing facilities. For the first time a ``narrow pathway'' to the middle of the island of stability was found owing to possible ${\ensuremath{\beta}}^{+}$ decay of SH nuclei ${}^{291}$115 and ${}^{291}$114 which could be formed in ordinary fusion reactions.

Macroscopic-microscopic calculations of ground state properties of superheavy nuclei

We systematically calculate the ground state properties of superheavy even-even nuclei with proton number Z=94–118. The calculations are based on the liquid drop macroscopic model and the microscopic model with the modified single-particle oscillator potential. The calculated binding energies and α-decay energies agree well with the experimental data. The reliability of the macroscopic-microscopic(MM)model for superheavy nuclei is confirmed by the good agreement between calculated results and experimental ones. Detailed comparisons between our calculations and Moller’s are made. It is found that the calculated results also agree with Moller’s results and that the MM model is insensitive to the microscopic single-particle potential. Calculated results are also compared with results from relativistic mean-field (RMF) model and from Skyrme-Hatree-Fock(SHF) model. In addition, half-lives, deformations and shape coexistence are also investigated. The properties of some unknown nuclei are predicted and they will be useful for future experimental researches of superheavy nuclei.

New Perspective on Properties of Superheavy Nuclei

Status of theoretical studies on superheavy nuclei is simply reviewed. We investigate the influence of nuclear deformation on half-lives of α-decay for long lifetime nuclei beyond ~(208)Pb. The range of the validity of relativistic mean-field model is analyzed and discussed. The conservation of parity in α-decay, cluster-radioactivity, and spontaneous fission of nuclei is stressed. New views on the properties of superheavy nuclei are presented.

Binding energies of even-even superheavy nuclei

The structure of the even-even superheavy nuclei with the proton number Z=98–110 is studied using the self-consistent relativistic mean-field theory. The calculated binding energies are in good agreement with the available experimental ones. An upper limit and a lower limit on the binding energies are set by the calculations. This is useful for future calculations of properties of superheavy nuclei and for the experimental synthesis of superheavy nuclei. The energy surface of some relevant superheavy nuclei is also given and it confirms the correctness of the calculations.

Theoretical study on the properties of some superheavy nuclei

The structures of some superheavy nuclei are investigated using self-consistent relativistic mean-field (RMF) model. The calculated binding energies and alpha-decay energies are in good agreement with experimental data. The theoretical lifetime reasonably agrees with the data. The properties of some unknown superheavy nuclei are predicted. A discussion on the deformed shell around Z=108 is made.

Deformed Relativistic Mean-field Calculations on the Properties of Superheavy Nuclei

Deformed Relativistic Mean-field Calculations on the Properties of Superheavy Nuclei

The Synthesis and Properties of Superheavy Nuclei Produced in the 48 Ca+ 244 Pu, 248 Cm Reactions

We present the results of the experiments aimed at producing hypothetical long-lived superheavy elements located near the spherical shell closures with Z>-114 and N>-172. For the synthesis of superheavy nuclei a combination of neutron-rich reaction partners, such as 244Pu and 248Cm targets and a 48Ca projectile have been used. The sensitivity of the present experiment exceeded by more than two orders of magnitude previous attempts to synthesize superheavy nuclides in reactions of 48Ca projectiles with actinide targets. We observed new decay sequences of genetically linked α-decays terminated by spontaneous fission. The decay properties of the synthesized nuclei are consistent with the consecutive α-decays originating from the parent nuclides 288,289114, produced in the 3n and 4n-evaporation channels, and 292116 — in the 4n-evaporation channel with cross sections of about a picobarn. The present observations can be considered an experimental evidence of the existence of the “island of stability” of superheavy elements and are discussed in terms of modern theoretical approaches.

Calculated properties of superheavy nuclei

Ground-state properties of the heaviest nuclei are analyzed within a macroscopic-microscopic approach. The main attention is paid to such properties as deformation, deformation energy, energy of the first rotational state 2+ of a nucleus, and the branching ratio of α decay to this 2+ state with respect to the decay to the ground state 0+. The analysis concerns the problem of experimental confirmation of theoretically predicted deformed shapes of superheavy nuclei situated in the region around the nucleus 270Hs. A large region of even-even nuclei with proton, Z=82–128, and neutron, N=126–190, numbers is considered.

Superheavy nuclei in deformed mean--field calculations

The ground–state properties of superheavy nuclei are investigated within various parametrisations of relativistic and nonrelativistic nuclear mean–field models. The heaviest known even–even nuclei starting with Z = 98 are used as a benchmark to estimate the predictive power of the models and forces. From that starting point, deformed doubly magic nuclei are searched in the region 100 ≤ Z ≤ 130 and 142 ≤ N ≤ 190.

Synthesis and properties of superheavy nuclei

Synthesis and properties of superheavy nuclei

Shell structure and stability of nuclei with 270<A<500 and the possible existence of primordial superheavy nuclei

The self-consistent energy density method is applied to the study of the properties of superheavy nuclei with 270<A<500. The shell structure,α-decay energy andα-decay half-life are predicted for the heaviestβ-stable isotope of each even element. The characteristics of nuclear densities and single-particle potentials in the superheavy region are also examined, with a particular attention on the surface diffuseness. After an approximate calculation of their fission barrier heights, only a few heavy isotopes of elements 106 and 108 are predicted to have a small chance to be found in nature. Their possible formation by ther-process is discussed.