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.

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.

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.

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.

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.

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.

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
Keyword(s):  
Alpha Decay ◽  
Nucleon Nucleon ◽  
Nuclear Potential ◽  
Cluster Decay ◽  
Superheavy Nuclei ◽  
Empirical Formulas ◽  
Folding Potential ◽  
Double Folding ◽  
Semi Empirical ◽  
Double Folding Potential

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.

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.

SINGLE-PARTICLE EFFECTS IN DECAY CHAINS OF ODD-A SUPERHEAVY NUCLEI

2006 ◽  
Vol 15 (02) ◽  
pp. 457-463 ◽  
Author(s):  
A. PARKHOMENKO ◽  
A. SOBICZEWSKI
Keyword(s):  
Single Particle ◽  
Decay Chain ◽  
Alpha Decay ◽  
Superheavy Nuclei ◽  
Microscopic Approach ◽  
Transition Energies ◽  
Free Parameters ◽  
The Absolute ◽  
The One ◽  
Good Agreement

Alpha-decay chain of 271 Ds (271110) is described theoretically. Transition energies [Formula: see text] and half-lives Tα are analyzed. The energies [Formula: see text] are described within a macroscopic-microscopic approach. Single-particle excitations of the nuclei are treated in the one-quasiparticle approximation. The half-lives Tα are described by a simple 3-parameter phenomenological formula expressing them as functions of [Formula: see text]. A good agreement with measured values is obtained. Average of the absolute values of the discrepancies for [Formula: see text] is 0.17 MeV. The half-lives Tα are reproduced within a factor of 3.8, on the average. No free parameters are used in the description.

scholarly journals Extended systematics of alpha decay half lives for exotic superheavy nuclei

2016 ◽  
Vol 951 ◽  
pp. 60-74 ◽  
Author(s):  
A.I. Budaca ◽  
R. Budaca ◽  
I. Silisteanu
Keyword(s):  
Alpha Decay ◽  
Superheavy Nuclei

ALPHA-DECAY STUDIES ON 130-153Eu NUCLEI

2013 ◽  
Vol 22 (11) ◽  
pp. 1350081 ◽  
Author(s):  
K. P. SANTHOSH ◽  
B. PRIYANKA
Keyword(s):  
Experimental Data ◽  
Potential Model ◽  
Alpha Decay ◽  
Shell Closure ◽  
Proximity Potential ◽  
Deformed Nuclei ◽  
Neutron Shell ◽  
Good Agreement ◽  
Neutron Shell Closure

The alpha-decay half-lives of the 24 isotopes of Eu (Z = 63) nuclei in the region 130≤A≤153, have been studied systematically within the Coulomb and proximity potential model (CPPM). We have modified the assault frequency and re-determined the half-lives and they show a better agreement with the experimental value. We have also done calculations on the half-lives within the recently proposed Coulomb and proximity potential model for deformed nuclei (CPPMDN). The computed half-lives are compared with the experimental data and they are in good agreement. Using our model, we could also demonstrate the influence of the neutron shell closure at N = 82, in both parent and daughter nuclei, on the alpha-decay half-lives.

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