PROPERTIES OF THE SUPERHEAVY NUCLEUS 294118 AND ITS α-DECAY CHAIN IN THE RELATIVISTIC MEAN FIELD THEORY

2008 ◽  
Vol 17 (07) ◽  
pp. 1309-1317
Author(s):  
FANG ZHOU ◽  
JIAN-YOU GUO

The superheavy nucleus 294118 and its α-decay chain have been investigated systematically in the relativistic mean-field (RMF) theory with the interactions NL3, TMA, PK1 and NLZ. The properties of ground state have been described well with the binding energies per nucleon and α-decay energies, which are reproduced as compared with the experimental data. It shows that the RMF theory is effective for studying not only the stable nuclei but also the superheavy nuclei presented here. In particular, the prolate shape predicted in the ground state of these superheavy nuclei is in agreement with the experimental data as well as other theoretical calculations.

2012 ◽  
Vol 21 (06) ◽  
pp. 1250055 ◽  
Author(s):  
M. RASHDAN

The NL-RA1 effective interaction of the relativistic mean field theory is employed to study the structure of deformed and superheavy nuclei, using an axially deformed harmonic oscillator basis. It is found that a fair agreement with the experimental data is obtained for the binding energies (BE), deformation parameters and charge radii. Comparison with NL-Z2, NLSH and NL3 interactions show that NL-Z2 gives good binding but larger radii, while NL-SH gives good radii but larger binding. The NL-RA1 interaction is also tested for the new deformed superheavy element with Z≥98. Excellent agreement with the experimental binding is obtained, where the relative error in BEs of Cf, Fm, No, Rf, Sg and Ea (Z = 110) isotopes are found to be of the order ~0.1%. The NL3 predicted larger binding and larger relative errors ~0.2–0.5%. Furthermore, the experimental Q-values of the alpha-decay of the superheavy elements 270110, 288114 and 292116 are satisfactory reproduced by NL-RA1 interaction, where the agreement is much better than that predicted by the phenomenological mass FRDM model. Furthermore, the alpha-decay chain of element 294118 are also better reproduced by NL-RA1 interaction.


Foundations ◽  
2022 ◽  
Vol 2 (1) ◽  
pp. 85-104
Author(s):  
Tolulope Majekodunmi Joshua ◽  
Nishu Jain ◽  
Raj Kumar ◽  
Khairul Anwar ◽  
Nooraihan Abdullah ◽  
...  

A new α-emitting has been observed experimentally for neutron deficient 214U which opens the window to theoretically investigate the ground state properties of 214,216,218U isotopes and to examine α-particle clustering around the shell closure. The decay half-lives are calculated within the preformed cluster-decay model (PCM). To obtain the α-daughter interaction potential, the RMF densities are folded with the newly developed R3Y and the well-known M3Y NN potentials for comparison. The alpha preformation probability (Pα) is calculated from the analytic formula of Deng and Zhang. The WKB approximation is employed for the calculation of the transmission probability. The individual binding energies (BE) for the participating nuclei are estimated from the relativistic mean-field (RMF) formalism and those from the finite range droplet model (FRDM) as well as WS3 mass tables. In addition to Z=84, the so-called abnormal enhancement region, i.e., 84≤Z≤90 and N<126, is normalised by an appropriately fitted neck-parameter ΔR. On the other hand, the discrepancy sets in due to the shell effect at (and around) the proton magic number Z=82 and 84, and thus a higher scaling factor ranging from 10−5–10−8 is required. Additionally, in contrast with the experimental binding energy data, large deviations of about 5–10 MeV are evident in the RMF formalism despite the use of different parameter sets. An accurate prediction of α-decay half-lives requires a Q-value that is in proximity with the experimental data. In addition, other microscopic frameworks besides RMF could be more reliable for the mass region under study. α-particle clustering is largely influenced by the shell effect.


2000 ◽  
Vol 09 (06) ◽  
pp. 507-520
Author(s):  
S. V. S. SASTRY ◽  
ARUN K. JAIN ◽  
Y. K. GAMBHIR

In the relativistic mean field (RMF) calculations usually the basis expansion method is employed. For this one uses single harmonic oscillator (HO) basis functions. A proper description of the ground state nuclear properties of spherical nuclei requires a large (around 20) number of major oscillator shells in the expansion. In halo nuclei where the nucleons have extended spatial distributions, the use of single HO basis for the expansion is inadequate for the correct description of the nuclear properties, especially that of the surface region. In order to rectify these inadequacies, in the present work an orthonormal basis composed of two HO basis functions having different sizes is proposed. It has been shown that for a typical case of (A=11) the ground state constructed using two-HO wave functions extends much beyond the second state or even third excited state of the single HO wave function. To demonstrate its usefulness explicit numerical RMF calculations have been carried out using this procedure for a set of representative spherical nuclei ranging from 16 O to 208 Pb . The binding energies, charge radii and density distributions have been correctly reproduced in the present scheme using a much smaller number of major shells (around 10) in the expansion.


2011 ◽  
Vol 20 (10) ◽  
pp. 2217-2228 ◽  
Author(s):  
B. K. SAHU ◽  
M. BHUYAN ◽  
S. MAHAPATRO ◽  
S. K. PATRA

We study the binding energy, root-mean-square radius and quadrupole deformation parameter for the synthesized superheavy element Z = 115, within the formalism of relativistic mean field theory. The calculation is dones for various isotopes of Z = 115 element, starting from A = 272 to A = 292. A systematic comparison between the binding energies and experimental data is made.The calculated binding energies are in good agreement with experimental result. The results show the prolate deformation for the ground state of these nuclei. The most stable isotope is found to be 282115 nucleus (N = 167) in the isotopic chain. We have also studied Qα and Tα for the α-decay chains of 287, 288115.


2011 ◽  
Vol 20 (11) ◽  
pp. 2293-2303 ◽  
Author(s):  
PROVASH MALI

The ground state properties namely the binding energy, the root mean square (rms) radius (neutron, proton and charge) and the deformation parameter of 45 newly identified neutron-rich isotopes in the A~71–152 mass region have been predicted in the relativistic mean filed (RMF) framework along with the Bardeen–Cooper–Schrieffer (BCS) type of pairing. Validity of the RMF results with the NL3 effective force are tested for odd-A Zn and Rh isotopic chains without taking the time reversal symmetry breaking effects into consideration. The RMF prediction on the binding energies are in good agreement with the empirical/finite-range droplet model calculation. The shell effects on the rms radii of odd-A Zn and Rh isotopes are nicely reproduced. The possibility of shape-coexistence in the newly identified nuclei is discussed.


2015 ◽  
Vol 24 (04) ◽  
pp. 1550028 ◽  
Author(s):  
M. Bhuyan ◽  
S. Mahapatro ◽  
S. K. Singh ◽  
S. K. Patra

We study the bulk properties such as binding energy (BE), root-mean-square (RMS) charge radius, quadrupole deformation etc. for Francium (Fr) isotopes having mass number A = 180–240 within the framework of relativistic mean field (RMF) theory. Systematic comparisons are made between the calculated results from RMF theory, Finite Range Droplet Model (FRDM) and the experimental data. Most of the nuclei in the isotopic chain shows prolate configuration in their ground state. The α-decay properties like α-decay energy and the decay half-life are also estimated for three different chains of 198 Fr , 199 Fr and 200 Fr . The calculation for the decay half-life are carried out by taking two different empirical formulae and the results are compared with the experimental data.


2021 ◽  
Author(s):  
Xiao-Qian Wang ◽  
Xiang-Xiang Sun ◽  
Shan-Gui 周善贵 Zhou

Abstract We study the effects of higher-order deformations βλ (λ = 4,6,8, and 10) on the ground state properties of superheavy nuclei (SHN) near the deformed doubly magic nucleus 270Hs by using the multidimensionally-constrained (MDC) relativistic mean-field (RMF) model with five effective interactions PC-PK1, PK1, NL3∗, DD-ME2, and PKDD. The doubly magic properties of 270Hs are featured by the large energy gaps at N = 162 and Z = 108 in the single-particle spectra. By investigating the binding energies and single-particle levels of270Hs in multidimensional deformation space, we find that the deformation β6 has the greatest impact on the binding energy among these higher-order deformations and influences the shell gaps considerably. Similar conclusions hold for other SHN near 270Hs. Our calculations demonstrate that the deformation β6 must be considered when studying SHN by using MDC-RMF.


2018 ◽  
Vol 27 (09) ◽  
pp. 1850074 ◽  
Author(s):  
G. Saxena ◽  
U. K. Singh ◽  
M. Kumawat ◽  
M. Kaushik ◽  
S. K. Jain ◽  
...  

A fully systematic study of even and odd isotopes [Formula: see text] of [Formula: see text] superheavy nuclei is presented in theoretical frameworks of Relativistic mean-field plus state dependent BCS approach and macroscopic–microscopic approach with triaxially deformed Nilsson-Strutinsky prescription. The ground state properties namely shell correction, binding energy, two- and one-proton and neutron separation energy, shape, deformation, density profile and the radius are estimated that show strong evidences for magicity in [Formula: see text], 228. Central depletion in the charge density due to large repulsive Coulomb field indicating bubble like structure is reported. A comprehensive analysis for the possible decay modes specifically [Formula: see text]-decay and spontaneous fission (SF) is presented and the probable [Formula: see text]-decay chains are evaluated. Results are compared with Finite Range Droplet Model (FRDM) calculations and the available experimental data which show excellent agreement.


2010 ◽  
Vol 19 (02) ◽  
pp. 291-298 ◽  
Author(s):  
H. AYTEKIN ◽  
R. BALDIK ◽  
E. TEL ◽  
A. AYDIN

Some ground states features of 32 S , 39 K , 40 Ca and 48 Ca nuclei are investigated using the Hartree–Fock method with the Skyrme SKM * and SLy4 forces calculated in two different code implementations. The calculated total binding energies per particle and root mean square (rms) nuclear charge radii using the Skyrme–Hartree–Fock (SHF) + BCS method are compared with relativistic mean-field (RMF) theory and experimental values. The obtained charge density distributions from these code implementations are compared with the experimental data. Pairing effects are also included in calculations for the same nuclei. Variations of the total binding energies per particle and rms nuclear charge radii were investigated as the last shell nucleons were carried to the upper shell.


2018 ◽  
Vol 27 (07) ◽  
pp. 1850062 ◽  
Author(s):  
Mamta Aggarwal ◽  
G. Saxena

Recent experimental observation of magicity in [Formula: see text]Ni has infused the interest to examine the persistence of the magic character across the [Formula: see text] shell gap in extremely neutron-rich exotic nucleus [Formula: see text]Ni in ground as well as excited states. A systematic study of Ni isotopes and [Formula: see text] isotones in ground state is performed within the microscopic framework of relativistic mean-field (RMF) theory and the triaxially deformed Nilsson–Strutinsky model (NSM). Ground state density distributions, charge form factors, radii, separation energies, pairing energies, single-particle energies and the shell corrections show strong magicity in [Formula: see text]Ni. Excited nuclei are treated within the statistical theory of hot rotating nuclei where the variations of level density parameter and entropy show significant magicity with a deep minima at [Formula: see text], which persists up to the temperatures [Formula: see text]1.5–2[Formula: see text]MeV and then slowly disappears with increasing temperature. Rotational states are evaluated and effect of rotation on [Formula: see text] ([Formula: see text]) isotones are studied. Our results agree very well with the available experimental data and few other theoretical calculations.


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