Fission Time Measurements: A New Probe into Superheavy Element Stability

Section: -P9mentioning

confidence: 99%

Nuclear Reaction Dynamics Research at the Australian National University

Hinde

Dasgupta

Carter

et al. 2013

“…Note that this simple picture neglects possible shell effects in the exit channel which may enhance the production of magic nuclei such as 208 Pb and "delay" the mass drift toward symmetry. In addition, long-time fission of super-heavy systems may occur via asymmetric channels [46,47], i.e., fusion-fission does not necessarily populate the region of the MAD around the M R = 0.5 axis.…”

Section: Quasi-fission: Interplay Between Shells and Isospinmentioning

confidence: 99%

Effects of nuclear structure on quasi-fission

Simenel

Wakhle

Avez

et al. 2012

Abstract. The quasi-fission mechanism hinders fusion of heavy systems because of a mass flow between the reactants, leading to a re-separation of more symmetric fragments in the exit channel. A good understanding of the competition between fusion and quasi-fission mechanisms is expected to be of great help to optimize the formation and study of heavy and superheavy nuclei. Quantum microscopic models, such as the time-dependent Hartree-Fock approach, allow for a treatment of all degrees of freedom associated to the dynamics of each nucleon. This provides a description of the complex reaction mechanisms, such as quasi-fission, with no parameter adjusted on reaction mechanisms. In particular, the role of the deformation and orientation of a heavy target, as well as the entrance channel magicity and isospin are investigated with theoretical and experimental approaches.

“…Three different systems have been studied in reverse kinematics with the blocking technique [5]: 208 Pb + Ge at 6.2 MeV/u, 238 U + Ni at 6.6 MeV/u and 238 U + Ge at 6.1 MeV/u, possibly leading to compound nuclei with Z CN = 114 , 120 and 124, respectively. All the coincident charged products were detected and identified by INDRA [9], a highly efficient detector array covering a solid angle close to 4π sr.…”

Section: Long Lifetime Components From the Blocking Technique In Singmentioning

confidence: 99%

“…In the followa e-mail: morjean@ganil.fr ing, we shall first present recent reaction time measurements through mass-angular correlations, highlighting fast processes leading to fission-like fragments in reactions between very heavy nuclei. We shall then present results of experiments [5,6] in which long lifetime components (τ > 10 −18 s) characteristic of fusion reactions were observed, associated with part of the reactions leading to fission-like fragment production.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

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

Morjean

Chbihi

Dasgupta

et al. 2013

Self Cite

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.