Narrow Results

The Coulomb and proximity potential model (CPPM), which comes under the class of fission models, has been used for the extensive study on the cluster decay process in ^298–336126 superheavy nuclei, and thus the probable cluster decays from the various isotopes of Z = 126 have been investigated and predicted. 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., have also been used for evaluating the cluster decay half lives of these nuclei, and a comparison of the predicted decay half lives with the values evaluated using CPPM reveals that our predicted values matches well with these theoretical values. The behaviour of the cluster half lives with the neutron number of the daughter nuclei can be clearly seen from the plots for log₁₀(T_1/2) against the neutron number of the daughter nuclei in the corresponding decay, and these plots depicts that for most of the decays, the half life are the minimum for the decay leading to a daughter with N = 184. The odd-even staggering (OES) could be seen to be more prominent in the emission of heavy odd-mass clusters. The Geiger-Nuttall plots of log₁₀(T_1/2) versus Q^-1/2 and the Universal curve between -lnP and log₁₀(T_1/2) for various clusters ranging from ¹⁴C to ³⁰Mg from ^288–339126 isotopes have also been studied, and are found to be linear. Our study also reveals fact that, in cluster decays of SHN, the role of neutron shell closure is crucial than proton shell closure. Also, most of the predicted half lives are well within the present experimental upper limit (10³⁰s) and lower limit (10^-6s) for measurements and hence these predictions may be of great use for further experimental investigation on alpha and cluster decay in the superheavy region.

The competition of cluster decay (CD) and α decay is investigated in the region of superheavy (SH) nuclei with atomic numbers Z = 104 – 124. Calculations of half-lives within analytical superasymmetric fission (ASAF) model are performed by using the newest AME12 mass table as well as different theoretical mass models to determine the energy released, Q. For α decay the calculations are made using semFIS (semi-empirical Fission) model. A trend toward shorter half-lives and larger branching ratios relative to alpha decay for heavier SHs is observed.

The cluster radioactivity of ^208–238Th was studied by using a fission-like model taking interacting potential as the sum of coulomb and proximity potentials. The emission of the particle is considered as a quantum tunneling penetration of the potential barrier in the semi-classical WKB approximation. The released energy is deduced from the new table of atomic mass evaluation (AME12) and from the Finite Range Droplet Model. The obtained decay half-lives are compared with the few available experimental values and those of the effective liquid drop model.