Spontaneous-fission half-lives for even nuclei withZ≥92

Abstract

The spontaneous-fission process for doubly even nuclei with $Z\ge 92$ is studied in a semi-empirical WKB framework. One-dimensional fission barrier potentials are established from theoretical deformation-energy surfaces based on the droplet model and the modified-oscillator model. The effects of axial asymmetry as well as reflection asymmetry have been taken into account. Macroscopic (irrotational flow) inertial-mass functions and alternatively microscopic (cranking model) intertial mass parameters have been employed for the calculation of the fission half-lives. With one over-all normalization parameter it is possible to fit the experimental half-lives to within a factor of 20 on the average. The resulting effective inertial-mass functions are used to estimate the stability of the transactinide elements. Only minor differences with previous estimates for the $\mathfrak{r}$ process and superheavy nuclei are encountered.