Prediction of Alpha Decay Half-Lives of Z = 118–121 Superheavy Nuclei with A ≤ 300 by Using the Double-Folding Potential

2019 ◽  
Vol 74 (7) ◽  
pp. 551-560 ◽  
Author(s):  
M. Sayahi ◽  
V. Dehghani ◽  
D. Naderi ◽  
S.A. Alavi

AbstractThe alpha decay half-lives ofZ= 118–121 superheavy nuclei withA≤ 300 are calculated by using the density-dependent nuclear potential in the framework of the WKB method. The Paris and Ried M3Y nucleon-nucleon potentials are used in the calculation of the double-folding potential, which the Paris potential predicts to be the larger value of the half-lives. The obtained half-lives with Paris parameterisation are compared with those using three semi-empirical formulas, namely the improved Sahu formula, the universal decay law for alpha decay, and the formula for both alpha decay and cluster decay. The predicted half-lives with double-folding lie in between the improved Sahu and universal decay law formulas for both alpha and cluster decay. However, it is closer to the universal decay law formula and obeys its trend in all the studied superheavy nuclei.

Author(s):  
S. A. Seyyedi

Alpha decay (AD) and spontaneous fission (SF) half-lives of superheavy nuclei [Formula: see text] have been studied within the density-dependent cluster model. The alpha-nucleus potentials were calculated using the double-folding model with the realistic M3Y nucleon–nucleon interaction. To calculate nuclear half-lives, several semi-empirical formulas were used in addition to the Wentzel–Kramers–Brillouin (WKB) approximation. The calculated AD half-lives agree well with the values computed by the analytical formulas of Royer, the semi-empirical formula of Poenaru et al. and the Viola–Seaborg systematic. To identify the mode of decay of these nuclei, the SF half-lives were calculated using the semi-empirical formula given by Xu et al. The results show that among the isotopes studied, isotopes [Formula: see text] can be survived from the SF and have a half-life greater than [Formula: see text][Formula: see text](s). The study predicts [Formula: see text] chains from isotopes [Formula: see text], [Formula: see text] chains from isotopes [Formula: see text], [Formula: see text] chains from isotopes [Formula: see text] and an AD from [Formula: see text]. These isotopes have a half-life long enough to be synthesized in the laboratory. Also, in the decay chains of these isotopes, it is observed that the nuclei [Formula: see text] have higher half-lives than their neighbors. The neutron numbers corresponding to these isotopes are [Formula: see text] indicating the magical or semi-magical behavior of these numbers, which is in good agreement with the research results.


2006 ◽  
Vol 21 (29) ◽  
pp. 2217-2232 ◽  
Author(s):  
M. E. KURKCUOGLU ◽  
H. AYTEKIN ◽  
I. BOZTOSUN

In this paper, a simultaneous analysis of the elastic scattering data of the 16 O +16 O system for the energy range 5–10 MeV/nucleon is performed theoretically within the framework of the optical model formalism, by using the α–α double folding cluster potential. The α–α double folding cluster potential is evaluated by using the α-cluster distribution densities in the usual nucleon–nucleon double folding process with an effective α–α interaction potential. The results of the α–α double folding cluster potential analysis are compared with the findings of the phenomenological Woods–Saxon squared and nucleon–nucleon double folding potentials. All potentials have exhibited a very good agreement with the experimental measurements for the elastic scattering angular distributions. Furthermore, it is shown that, the α–α double folding cluster potential and nucleon–nucleon double folding potential calculations provide very consistent results with each other. Thus, the 16 O+ 16 O system has been described by optical potentials having a deep real potential part and a weak absorptive imaginary potential part.


2021 ◽  
pp. 2150033
Author(s):  
S. A. Seyyedi

Alpha-decay half-lives of the even–even superheavy isotopes with proton numbers [Formula: see text] have been calculated within the cluster model. The alpha-daughter potential was constructed by employing the density-dependent double-folding model with a realistic nucleon–nucleon interaction whose exchange part has a finite range approximation. The half-lives were calculated using Wentzel–Kramers–Brillouin (WKB) approximation with the alpha preformation factor. The results have shown that the computed alpha-decay half-lives were in good agreement with their counterpart calculated by different semi-empirical approaches. The obtained results have also shown a negative linear relationship between the logarithm of the preformation factor and the fragmentation potential for the understudy isotopes. Also, the calculated results have shown that isotopes [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] had longer half-lives than their adjacent isotopes, which indicates that the corresponding neutron or proton numbers have a magical or semi-magical properties. Furthermore, we have studied the competition between alpha-decay and spontaneous fission to predict possible decay modes from the even–even isotopes [Formula: see text]. The results revealed that the isotopes [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] had alpha-decay as a predominant mode of decay and the nuclei [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] could not survive from the spontaneous fission. We hope that the theoretical prediction could be helpful for future investigation in this field.


2002 ◽  
Vol 11 (05) ◽  
pp. 437-444 ◽  
Author(s):  
N. A. El-NOHY ◽  
F. A. EL-AKKAD ◽  
A. M. ABDEL-MONEM ◽  
O. S. ABDEL-FATTAH

A double folding potential has been used to calculate the real part of optical potential of 6 Li scattering by 12 C , 40 Ca , 90 Zr and 208Pb. In this model the effective nucleon-nucleon interaction potential has been developed to include an energy and density dependent in a simple form. The real part of the optical potential calculated by the double folding model is then reduced to an equivalent Wood–Saxon form using a fitting program. The obtained Wood–Saxon potentials have been used to calculate the differential cross sections for elastic scattering of 6 Li nucleus by 12 C , 40 Ca , 90 Zr and 208 Pb . This method gives satisfactory agreement of the calculated differential scattering cross section with the corresponding experimental values.


1998 ◽  
Vol 07 (05) ◽  
pp. 625-638 ◽  
Author(s):  
A. Sandulescu ◽  
A. Florescu ◽  
F. Carstoiu ◽  
A. V. Ramayya ◽  
J. H. Hamilton ◽  
...  

A new phenomenon is studied: the cold (neutronless) ternary α-accompanied fragmentation of 252Cf. The corresponding isotopic yields were calculated as the ratio of the penetrability of a given fragmentation over the sum of penetrabilities of all possible (neutronless) α-ternary fragmentations. No preformation factors were considered. We considered that close to the scission configuration the nucleons of the alpha particle form a small neck. At a given value of the neck radius a double scission takes place and a third light fragment is formed between the two heavier fragments. The corresponding barriers between the light and heavy fragment and between the alpha particle and the two heavier fragments were evaluated by using a double folding potential generated by M3Y nucleon-nucleon forces and realistic fragment ground state deformations. The relative calculated isotopic yields greater than 2 × 10-3 have been observed experimentally for the partners with known spectra. We predict that fragmentations with unknown light partners 105,106Zr, 109,110Mo and 114Ru to be identified in the present data.


2019 ◽  
Vol 35 (06) ◽  
pp. 2050016 ◽  
Author(s):  
H. C. Manjunatha ◽  
N. Sowmya ◽  
A. M. Nagaraja

We have formulated a semi-empirical formula for alpha decay half-lives and cluster decay half-lives for superheavy nuclei of atomic number range [Formula: see text]. We have compared the logarithmic half-lives produced by the present formula with that of experiments and other formulae, such as universal decay law (UDL) [H. C. Manjunatha and K. N. Sridhar, Eur. Phys. J. A 53, 156 (2017)] and Horoi et al. [Horoi et al., J. Phys. G[Formula: see text] Nucl. Part. Phys. 30, 945 (2004)], Univ [D. Ni and Z. Ren, Phys. Rev. C 74, 014304 (2006)], Royer [G. Royer, J. Phys. G: Nucl. Part. Phys. 26, 1149 (2000)] and VSS [S. A. Gurvitz and G. Kalbermann, Phys. Rev. Lett. 59, 262 (1987)]. The constructed formula produces logarithmic half-lives for alpha and cluster decay (4He,9Be, [Formula: see text]B, [Formula: see text]C, [Formula: see text]N, [Formula: see text]O, [Formula: see text]F, [Formula: see text]Ne, [Formula: see text]Na, [Formula: see text]Mg, [Formula: see text]Al, [Formula: see text]Si, [Formula: see text]P, [Formula: see text]S, [Formula: see text]Cl, [Formula: see text]Ar, [Formula: see text]K and [Formula: see text]Ca) in superheavy nuclei of atomic number range [Formula: see text].


2019 ◽  
Vol 28 (06) ◽  
pp. 1950045 ◽  
Author(s):  
B. Nandana ◽  
R. Rahul ◽  
S. Mahadevan

[Formula: see text]-value and half-life of elements in alpha decay chain of [Formula: see text]117, [Formula: see text]117, [Formula: see text]116 and [Formula: see text]116 were calculated using the Nuclear potential generated by double folding procedure and using the WKB method treating the alpha decay as a tunneling problem. The nuclear potential was parameterized using Woods–Saxon potential. Using this approach, the [Formula: see text]-value and half-life of next heaviest element in the alpha decay chain of element [Formula: see text]116 is predicted. It is proposed to use this to predict the [Formula: see text]-value and half-life of other higher elements in different alpha decay chains.


2020 ◽  
Vol 29 (10) ◽  
pp. 2050087
Author(s):  
N. Sowmya ◽  
H. C. Manjunatha ◽  
P. S. Damodara Gupta

In this work, we have made an attempt to study the cluster-decay half-lives and alpha-decay half-lives of the superheavy nuclei [Formula: see text]Og by considering the temperature-dependent (TD) and also temperature-independent (TID) proximity potential model. The evaluated half-lives were compared with that of the experiments. To predict the decay modes, we have compared the cluster-decay half-lives and alpha-decay half-lives with that of spontaneous fission half-lives. This work also predicts the decay chains of the superheavy nuclei [Formula: see text]Og and finds an importance in the synthesis of further isotopes of superheavy element Oganesson.


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