Empirical description of -delayed fission partial half-lives

経験式による崩壊遅延核分裂の半減期

Ghys, L.*; Andreyev, A. N.; Antalic, S.*; Huyse, M.*; Van Duppen, P.*

Ghys, L.*; Andreyev, A. N.; Antalic, S.*; Huyse, M.*; Van Duppen, P.*

The process of -delayed fission (DF) provides a versatile tool to study low-energy fission in nuclei far away from the -stability line, especially for nuclei which do not fission spontaneously. The aim of this paper is to investigate systematic trends in DF partial half-lives. A semi-phenomenological framework was developed to systematically account for the behavior of DF partial half-lives. The DF partial half-life appears to exponentially depend on the difference between the Q value for decay of the parent nucleus and the fission-barrier energy of the daughter (after decay) product. Such dependence was found to arise naturally from some simple theoretical considerations. This systematic trend was confirmed for experimental DF partial half-lives spanning over seven orders of magnitude when using fission barriers calculated from either the Thomas-Fermi or the liquid-drop fission model. The same dependence was also observed, although less pronounced, when comparing to fission barriers from the finite-range liquid-drop model or the Thomas-Fermi plus Strutinsky integral method.