0000000000372364
AUTHOR
G.f. Prete
Fission dynamics: The quest of a temperature dependent nuclear viscosity
This paper presents a journey within some open questions about the current use of a temperature dependent nuclear viscosity in models of nuclear fission and proposes an alternative experimental approach by using systems of intermediate fissility. This study is particularly relevant because: i) systems of intermediate fissility offer a suitable frame-work since the intervals between the compound nucleus and scission point temperatures with increasing excitation energy are much smaller than in the case of heavier systems, ii) the dependence of viscosity on the temperature may change with the fissility of the composite system; iii) the opportunity to measure also observables in the evaporation…
Alpha-particle transfer from 6Li to 28Si leading to high excitation of 32S
The excitation of 32S to energies from 24 to 37 MeV followed by its decay to 28Si has been brought about by the two-step alpha transfer reaction 28Si(6Li,d)32S*→α+28Si. A sudden perishing of the decay to the 28Si ground state occurs at 31 MeV of excitation. At about the same energy an increase in the decay to the first excited 2+ state is observed. The yields of 28Si in its ground state or excited to the 21+ and 41+ state prohibit strong fluctuations. This supports the assumption of the existence of states at high excitation in 32S. The results are based on d–α coincidences, which were found to exhibit a strong forward–backward correlation.
Investigation of the reaction 64Ni+238U being an option of synthesizing element 120
This study is concerned with the search for entrance channels suitable to synthesize elements with Z > 118. Mass-energy distributions as well as capture cross-sections of fission-like fragments have been measured for the reactions 64Ni + 238U → 302120 and 48Ca + 238U → 286112 at energies near the Coulomb barrier. Compound nucleus fission cross-sections were estimated from the analysis of mass and total kinetic energy distributions. The cross-section drops three orders of magnitude for the formation of the compound nucleus with Z = 120 obtained in the reaction 64Ni + 238U compared to the formation of the compound nucleus with Z = 112 obtained in the reaction 48Ca + 238U at an excitation ener…