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 ission 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 residues channel translates into a larger set of effective constraints for the models. 

Keywords:- fission dynamics; nuclear viscosity; dynamical models; intermediate fissility systems; charged particle multiplicities 

Authors:- E. Vardaci, A. Brondi, G. La Rana, R. Moro

Istituto Nazionale di Fisica Nucleare and Diparimento di Fisica, Universit ´a degli Studi di Napoli "FedericoII",Napoli, 80126, Italy
A. Di Nitto
Johannes Gutenberg- Universit ¨at Mainz Institut f ¨ur Kernchemie, Mainz, Germany
P.N. Nadtochy
Omsk State University, Mira prospekt 55-A, Omsk 644077, Russia
M. Cinausero, G.Prete 
Laboratori Nazionali di Legnaro dell’Istituto Nazionale di Fisica Nucleare, Legnaro (Padova), 35020, Italy
N. Gelli