Recalculated Viola-Seaborg Coefficients for Partial Alpha Half-lives Based on AME2016

In this paper, the systematics for obtaining the Viola-Seaborg formula (VSF) for logarithmic partial alpha half-lives (Tα1/2) have been undertaken based on the NUBASE2016 evaluation. The constants Az and Bz in Geiger-Nuttal law for determination of Tα1/2 , are obtained using gs-gs transitions data, of even-even nuclei for two sets of nuclei with Z = 84 - 102 and Z = 86 - 98 with N > 126. The Viola-Seaborg co-efficients are determined for both the sets. The obtained parameters for both sets are tested on even-even nuclei for Z ranging from 104 - 118 and it is observed that first set parameters fare better. This formula for estimating α-decay half-lives of heavy nuclei can be extrapolated to predict those of super-heavy nuclei. The logarithmic half-lives Tα1/2 obtained for isotopes of Z = 121 and 122 using current modified VSF (AME2016) are compared with those obtained from theoretical considerations using Coulomb and proximity potential model (CPPM) and observed to be much larger. They are also much larger than those obtained from the previous coefficients based on AME2003 data.

Possible ternary fission of super-heavy nuclei

In super-heavy nuclei, we may expect to discover new phenomena because of the strong Coulomb force. One example is the true ternary fission. We study the sequential two binary fission of 300120 and 252Cf that produces three fragments. We use the Metropolis method to estimate the probability of the second fission. The probability of the second fission is 10−4-10−3 for superheavy nuclei while it is 10−7−10−6 for heavy actinide nuclei. The most probable mass division is almost symmetric in the case of 300120. We also demonstrate the applicability of the Metropolis method to a non-equilibrium process by comparing it with the Langevin equation.

Investigations on the study of entrance channel effects in synthesis of superheavy elements using Cr-induced fusion reactions

We have investigated the synthesis of superheavy elements using Cr-induced fusion reactions. We have studied all possible Cr-induced fusion reactions for the synthesis of super heavy nuclei [Formula: see text]. We have achieved the semi-empirical formula for fusion barrier heights ([Formula: see text]), positions ([Formula: see text]), curvature of the inverted parabola ([Formula: see text]) of Cr-induced fusion reactions for the synthesis of superheavy nuclei with atomic number range [Formula: see text]. The proposed formula produces fusion barriers of Cr-induced fusion reactions for the synthesis of super heavy nuclei with the simple inputs of mass number ([Formula: see text]) and atomic number ([Formula: see text]) of projectile-targets. We have also identified the targets for Cr-induced fusion reactions to synthesis superheavy elements of [Formula: see text]. We have also studied the entrance channel parameters such as mass asymmetry ([Formula: see text]), charge asymmetry ([Formula: see text]), coulomb interaction parameter ([Formula: see text]’), Businaro–Gallone mass asymmetry parameter ([Formula: see text]) and Isospin asymmetry parameter [[Formula: see text]]. We hope that our predictions may be the guide for the future experiments in the synthesis of more superheavy elements using [Formula: see text]Cr-induced fusion reactions.