Conférences et séminaires » Séminaire présenté par Krzysztof Pomorski, University MCS, Poland
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Light-particle emission from deformed, hot and rotating nuclei, within the Langevin dynamics and the four-dimensional LSD model
Par : Krzysztof Pomorski, Division of Theoretical Physics, University MCS, Lublin, Poland
Date : mardi 9 novembre 2010 à 11h00
Lieu : IPHC, Salle de Réunion 2e étage du Bâtiment 27
Résumé : The multiplicity and the characteristics (energies, angular distributions, correlation functions) of prefission light particles and gamma emission may provide some useful information on the time evolution of the compound nucleus as it evolves towards the saddle and scission point. Observables like prefission light-particle multiplicities may, indeed, work as a clock. Angular distributions and particle correlations may give information on the surface and deformation of the fissioning nucleus. A model treating fission dynamics in conjunction with light-particle (n, p, alpha) evaporation will be presented.
The particle emission rates are calculated in the framework of Weisskopf’s theory taking into account the excitation, rotation and deformation of the emitting nucleus (which is not the case for most other models). The competition between fission and evaporation is treated in a Monte Carlo procedure by drawing successive random numbers to decide whether a particle is emitted, and, in that case, which kind of particle and with which energy.
We are going to describe the dynamics of the fission process through the solution of a classical Langevin equation for collective variables characterising the nuclear elongation, nonaxiality, neck-formation and mass asymmetry using the Modified Funny Hill nuclear shape parametrisation. The potential energy surface will be generated using a model consisting of the Lublin-Strasbourg-Drop and the Yukawa-folded single-particle potential, which reproduces accurately not only the nuclear ground state masses but also the fission barrier heights.
Personne à contacter : Kamila SIEJA