Long lifetime components in the decay of excited super-heavy nuclei

Abstract

Abstract. For nuclear reactions in which super-heavy nuclei can be formed, the essential difference between the fusion process followed by fission and non-equilibrium processes leading to fission-like fragments is the reaction time. Quite probable non-equilibrium processes, characterized by very short reaction times, are highlighted thanks to mass-angle correlations. However, long lifetime components associated with fission following fusion have been observed with two independent experimental techniques, providing evidence for the formation of compound nuclei with Z = 120 and 124, followed by mass asymmetric fission.

Mapping quasifission characteristics in heavy element formation reactions

“…Even where quasifission is dominant, there is the possibility of a fraction of late-chance fusion-fission events with lifetimes of 10 −18 s or longer [22]. The MAD is quite insensitive to different time distributions for fission slower than 10 · 10 −21 s. However, other experimental techniques are sensitive only to fission with very long time scales, such as the crystal blocking [23] and X-ray techniques [24] recently applied by Morjean and co-workers in superheavy element formation reactions.…”

Induced Fission ofPu240within a Real-Time Microscopic Framework

“…The strong energy exchange between a large number of CDOF appears to be at the root of the slowness of this unexpected dynamics. There are experimental indications that fission times can be extremely long [96][97][98].…”