Alpha decay half-lives of superheavy nuclei 104 ≤ Z ≤ 125

Author(s):  
L. Vasanthi ◽  
N. S. Rajeswari

In order to describe scattering, fusion, fission and ground state masses, Krappe and collaborators developed unified nuclear potential, by generalizing liquid drop model. They have incorporated phenomenological parameters accounting for the attractive force between two separated fragments. One of the phenomenological parameters involved in this model is the range of folded Yukawa function, which accounts for surface diffuseness of the potential and short range attractive interaction. The role of range of folding function of Yukawa-plus-exponential potential is analyzed for alpha decay of heavy and superheavy nuclei. Significant effect of this function is noted in preformation probability which improves the accuracy of half-lives of alpha decay. Half-lives for alpha decay are better obtained for two values of the range of folding function 0.54 and 0.8[Formula: see text]fm for heavy and superheavy mass regions, respectively. The study confirms the associated shell structure [Formula: see text] in heavy nuclei and [Formula: see text] and [Formula: see text] in superheavy nuclei. The calculations are extended to predict the half-lives of superheavy nuclei with [Formula: see text] and [Formula: see text] which are not yet synthesized experimentally.

2018 ◽  
Vol 33 (14) ◽  
pp. 1850080 ◽  
Author(s):  
V. Dehghani ◽  
S. A. Alavi ◽  
Kh. Benam

By using WKB method and considering deformed Woods–Saxon nuclear potential, deformed Coulomb potential, and centrifugal potential, the alpha decay half-lives of 68 superheavy alpha emitters have been calculated. The effect of the constant value of surface diffuseness parameter in the range of 0.1 [Formula: see text]a [Formula: see text] 0.9 (fm) on the potential barrier, tunneling probability, assault frequency, and alpha decay half-lives has been investigated. Significant differences were observed for alpha decay half-lives and decay quantities in this range of surface diffuseness. Good agreement between calculated half-lives with fitted surface diffuseness parameter a = 0.54 (fm) and experiment was observed.


2009 ◽  
Vol 33 (S1) ◽  
pp. 95-97 ◽  
Author(s):  
Zhang Hong-Fei ◽  
Wang Zu-Kai ◽  
Cheng Xi-Meng ◽  
Zuo-Wei ◽  
Li Jun-Qing

2021 ◽  
pp. 1-9
Author(s):  
M. Hosseini-Tabatabaei ◽  
S.A. Alavi ◽  
V. Dehghani

Using the semiclassical WKB method and considering the WKB quantization condition, the alpha decay half-lives of 420 alpha emitters were calculated with eight forms of the proximity and Woods–Saxon type potentials. The effect of quantization condition on the nuclear potential, effective potential, assault frequency, tunneling probability, alpha decay half-life, and root mean square deviation between theory and the experiment were investigated. Significant differences between calculated half-lives with and without inclusion of the quantization condition were observed specially for proximity potentials. By including the quantization, the Woods–Saxon potential was found as the best potential for even–even, even–odd, odd–even, odd–odd, and all alpha emitters. The quantization condition normalized the nuclear potentials. Therefore, by considering this condition, the thirteen forms of the prox77 potential with different sets of the surface energy and surface asymmetry constants gave the same results. This result was justified with two sets of parameters.


Author(s):  
G. R. Sridhara ◽  
H. C. Manjunatha ◽  
N. Sowmya ◽  
P. S. Damodara Gupta

In this paper, we have made an attempt to analyze the alpha-decay half-lives of in the atomic number range [Formula: see text] by considering an effective liquid drop model. The role of pre-formation probability by including iso-spin effect is included during an evaluation of half-lives. We have also compared the studied alpha-decay half-lives with that of semi-empirical formulae such as Viola Seaborg semi-empirical formulae (VSS) [J. Inorg. Nucl. Chem. 28 (1966) 741; Nucl. Phys. A 848 (2010) 279], Royer formulae [J. Phys. G: Nucl. Part. Phys. 26 (2000) 1149; Phys. Rev. C 101 (2020) 034307] and also with that of the available experiments. From this comparison, it can be concluded that the effective liquid drop model produces an alpha-decay half-lives close to the experiments.


2008 ◽  
Vol 17 (10) ◽  
pp. 2270-2274 ◽  
Author(s):  
GUY ROYER ◽  
HONGFEI ZHANG

The α decay potential barriers are determined in the cluster-like shape path within a generalized liquid drop model including the proximity effects between the α particle and the daughter nucleus and adjusted to reproduce the experimental Qα. The α emission half-lives are determined within the WKB penetration probability. Calculations using previously proposed formulae depending only on the mass and charge of the alpha emitter and Qα are also compared with new experimental alpha-decay half-lives. The agreement allows to provide predictions for the α decay half-lives of other still unknown superheavy nuclei using the Qα determined from the 2003 atomic mass evaluation of Audi, Wapstra and Thibault.


2017 ◽  
Vol 95 (1) ◽  
pp. 31-37 ◽  
Author(s):  
K.P. Santhosh ◽  
Indu Sukumaran

The alpha decay and heavy particle radioactivity of the isotopes of even–even superheavy nuclei with Z = 122–132 have been studied within Coulomb and proximity potential model. The predicted half-lives using our model are found to be in agreement with universal formula for cluster decay of Poenaru et al., the universal decay law of Qi et al., and the scaling law of Horoi et al., and most of the estimated values are well within the experimental upper limit (T1/2 < 1030 s). Our work targets the shell closure properties in the superheavy region. From the plots for log10(T1/2) against the neutron number of the daughter nuclei, three prominent minima are observed at N = 178, 184, and 194. The results show that in addition to N = 184, the neutron numbers N = 178 and 194 exhibit extra stability as compared to their neighbours. Based on these important observations, we have identified the possibility of N = 194 being a magic neutron number next to N = 184. Further, a new island of stability in the superheavy region has been predicted around the doubly magic 304120 superheavy nuclei and thus established the role of neutron shell closure in heavy particle decays very well.


1971 ◽  
Vol 26 (4) ◽  
pp. 643-652 ◽  
Author(s):  
Jens Grumann ◽  
Tihomir Morovic ◽  
Walter Greiner

AbstractThe potential energy surface has been calculated by two methods which are compared with re­spect to spontaneous fission. In the first one essentially the sum of the single particle energies is computed as was done in a previous paper3 while in the second one the Strutinsky technique of renormalizing to a liquid drop model has been applied. Also the half-lives for electron capture are investigated together with the predictions of the half-lives for spontaneous fission and α-decay. The results support the existence of superheavy nuclei in the regions around Z = 114 and Z = 164.


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.


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