Role of constant value of surface diffuseness in alpha decay half-lives of superheavy nuclei

2018 ◽  
Vol 33 (14) ◽  
pp. 1850080 ◽  
Author(s):  
V. Dehghani ◽  
S. A. Alavi ◽  
Kh. Benam
Keyword(s):  
Alpha Decay ◽  
Tunneling Probability ◽  
Nuclear Potential ◽  
Superheavy Nuclei ◽  
Wkb Method ◽  
Alpha Emitters ◽  
Surface Diffuseness ◽  
Diffuseness Parameter ◽  
Good Agreement

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.

Systematic of alpha decay half-lives: role of quantization condition

2021 ◽  
pp. 1-9
Author(s):  
M. Hosseini-Tabatabaei ◽  
S.A. Alavi ◽  
V. Dehghani
Keyword(s):  
Alpha Decay ◽  
Tunneling Probability ◽  
Quantization Condition ◽  
Nuclear Potential ◽  
Mean Square ◽  
Mean Square Deviation ◽  
Wkb Method ◽  
Saxon Potential ◽  
Alpha Emitters

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.

EFFECT OF NUCLEAR DEFORMATION ON THE POTENTIAL BARRIER AND ALPHA-DECAY HALF-LIVES OF SUPERHEAVY NUCLEI

2013 ◽  
Vol 28 (16) ◽  
pp. 1350065 ◽  
Author(s):  
M. R. PAHLAVANI ◽  
S. A. ALAVI ◽  
N. TAHANIPOUR
Keyword(s):  
Potential Barrier ◽  
Alpha Decay ◽  
Superheavy Elements ◽  
Nuclear Potential ◽  
Superheavy Nuclei ◽  
Nuclear Deformation ◽  
Centrifugal Term ◽  
Wkb Method ◽  
Theory And Experiment ◽  
Good Agreement

The alpha-decay half lives of superheavy elements have been calculated in the framework of WKB method. The effective potential has been considered as summation of the deformed Woods–Saxon nuclear potential, deformed Coulomb potential and centrifugal term. The quadrupole, hexadecapole and hexacontatetrapole deformations have been included in the calculation. The effect of hexacontatetrapole deformation on the potential barrier has been presented, separately. The good agreement between theory and experiment has been observed for alpha-decay half-lives of heavy and superheavy elements.

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

2021 ◽  
pp. 2150071
Author(s):  
L. Vasanthi ◽  
N. S. Rajeswari
Keyword(s):  
Liquid Drop ◽  
Alpha Decay ◽  
Nuclear Potential ◽  
Superheavy Nuclei ◽  
Heavy Nuclei ◽  
Exponential Potential ◽  
Heavy And Superheavy Nuclei ◽  
Surface Diffuseness ◽  
Structure Formula

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.

Calculation of Q-value and half-life of alpha-decay chains of superheavy elements using double folding method

2019 ◽  
Vol 28 (06) ◽  
pp. 1950045 ◽  
Author(s):  
B. Nandana ◽  
R. Rahul ◽  
S. Mahadevan
Keyword(s):  
Half Life ◽  
Decay Chain ◽  
Alpha Decay ◽  
Superheavy Elements ◽  
Nuclear Potential ◽  
Wkb Method ◽  
Saxon Potential ◽  
Q Value ◽  
Double Folding

[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.

Correlation between alpha preformation probability, decay half-life and barrier assault frequency

2017 ◽  
Vol 26 (05) ◽  
pp. 1750026 ◽  
Author(s):  
M. Ismail ◽  
A. Y. Ellithi ◽  
A. El-Depsy ◽  
O. A. Mohamedien
Keyword(s):  
Barrier Height ◽  
Alpha Particle ◽  
Half Life ◽  
Alpha Decay ◽  
Strong Correlations ◽  
Alpha Emitters ◽  
Barrier Penetration ◽  
Penetration Probability ◽  
Good Agreement

Calculation of alpha particle preformation probabilities for some alpha emitters is considered in the framework of a recent proposed barrier penetration formula, by two different approximations. The behavior of alpha particle preformation probability with the variation of neutron and proton numbers of parent nuclei for isotopes, in the range [Formula: see text], and isotones, in the range [Formula: see text], is investigated. The same correlations are then studied for the alpha decay half-life, the barrier assault frequency, barrier height and barrier penetration probability. Strong correlations are found and in a good agreement with experimental expectations.

Theoretical prediction of probable isotopes of superheavy nuclei of Z = 122

2016 ◽  
Vol 25 (11) ◽  
pp. 1650100 ◽  
Author(s):  
H. C. Manjunatha
Keyword(s):  
Theoretical Prediction ◽  
Spontaneous Fission ◽  
Decay Channel ◽  
Superheavy Element ◽  
Alpha Decay ◽  
Superheavy Nuclei ◽  
Semiempirical Relation ◽  
Analytical Formulas ◽  
C 78 ◽  
Good Agreement

We have studied the [Formula: see text]-decay half-life and spontaneous fission half-lives of isotopes of superheavy element [Formula: see text] in the range [Formula: see text]. A comparison of calculated alpha half-lives with the literature [D. N. Poenaru, R. A. Gherghescu and W. Greiner, Phys. Rev. C 83 (2011) 014601, D. N. Poenaru, R. A. Gherghescu and W. Greiner, Phys. Rev. C 85 (2012) 034615] and the analytical formulas of Royer [G. Royer, J. Phys. G; Nucl. Part. Phys. 26 (2000) 1149] shows good agreement with each other. To identify the mode of decay of these isotopes, the spontaneous-fission half-lives were also evaluated using the semiempirical relation given by [C. Xu, Z. Ren and Y. Guo, Phys. Rev. C 78 (2008) 044329]. A comparative study on the competition of alpha decay versus spontaneous fission of superheavy nuclei (SHN) reveals that around eight isotopes ([Formula: see text]122) survive fission and have alpha decay channel as the prominent mode of decay and hold the possibility to be synthesized in the laboratory. The alpha decay half-lives and spontaneous fission half-lives of SHN with [Formula: see text], [Formula: see text]–306, with [Formula: see text], [Formula: see text]–300, and with [Formula: see text], [Formula: see text]–297 are also studied. The present study will be useful in the synthesis of superheavy elements [Formula: see text] by using the actinide based reactions with stable projectiles heavier than [Formula: see text]Ca.

Effect of Surface Diffuseness Parameter on Quasi-elastic Scattering Calculations for 16O+208Pb,63Cu Systems

2021 ◽  
Vol 19 (10) ◽  
pp. 100-105
Author(s):  
Nagham H. Hayef ◽  
Khalid S. Jassim
Keyword(s):  
Relative Motion ◽  
Cross Sections ◽  
Single Channel ◽  
Nuclear Potential ◽  
Channel Calculation ◽  
Coupled Channels ◽  
Coupled Channel Calculation ◽  
Surface Diffuseness ◽  
Diffuseness Parameter ◽  
Coupled Channel

A systematic study on the surface characteristic of the nucleus-nucleus potential for some heavy-ion. The nuclear potential has been described by using Woods-Saxon (WS), the single-channel (SC) and the coupled-channels (CC) calculations, which were between the relative motion of the colliding nuclei and their intrinsic motions, were conducted to study its influence on calculation, the ratio of the quasi-elastic to the Rutherford cross sections and probe the surface diffuseness method was used to find the best fitted value of the diffuseness parameters in comparison with the experimental data. We find that the best fitted value of the diffuseness parameter which obtained through a coupled-channel calculation with inert target and excited projectile forIn the current work, the single-channel (SC) and the coupled-channels (CC) calculations, which were between the relative motion of the colliding nuclei and their intrinsic motions, were conducted to study its influence on calculation, the ratio of the quasi-elastic to the Rutherford cross sections and probe the surface diffuseness find that the best fitted value of the diffuseness parameter which obtained through a coupled-channel calculation with excited target and projectile excited also inert projectile-excited target for the 16O+208Pb andexcited projectile and inert target for the 16O+63Cu.

Studies on heavy particle radioactivity from superheavy nuclei leading to doubly magic 304120 daughter nuclei

2017 ◽  
Vol 95 (1) ◽  
pp. 31-37 ◽  
Author(s):  
K.P. Santhosh ◽  
Indu Sukumaran
Keyword(s):  
Scaling Law ◽  
Heavy Particle ◽  
Alpha Decay ◽  
Neutron Number ◽  
Cluster Decay ◽  
Superheavy Nuclei ◽  
Shell Closure ◽  
Proximity Potential ◽  
Particle Decays

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.

scholarly journals Probable cluster decays from 270–318118 superheavy nuclei

2014 ◽  
Vol 23 (10) ◽  
pp. 1450059 ◽  
Author(s):  
K. P. Santhosh ◽  
B. Priyanka
Keyword(s):  
Half Life ◽  
Potential Model ◽  
Scaling Law ◽  
Alpha Decay ◽  
Neutron Number ◽  
Cluster Decay ◽  
Superheavy Nuclei ◽  
Proximity Potential ◽  
Universal Formula ◽  
Good Agreement

The cluster decay process in 270–318118 superheavy nuclei has been studied extensively within the Coulomb and proximity potential model (CPPM), thereby investigating the probable cluster decays from the various isotopes of Z = 118. On comparing the predicted decay half-lives with the values evaluated using the Universal formula for cluster decay (UNIV) of Poenaru et al., the Universal Decay Law (UDL) of Qi et al., and the Scaling Law of Horoi et al., it was seen that, our values matches well with these theoretical values. A comparison of the predicted alpha decay half-life of the experimentally synthesized superheavy isotope 294118 with its corresponding experimental value shows that, our theoretical value is in good agreement with the experimental value. The plots for log 10(T1/2) against the neutron number of the daughter in the corresponding decay reveals the behavior of the cluster half-lives with the neutron number of the daughter nuclei and for most of the decays, the half-life was found to be the minimum for the decay leading to a daughter with N = 184. Most of the predicted half-lives are well within the present experimental upper limit (1030 s) and lower limit (10-6 s) for measurements and hence these predictions may be of great use for further experimental investigation on cluster decay in the superheavy region.

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