Search for Multifragmentation Near Threshold in the 3-He + Ag Reaction

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

Multifragment Emission in the 3-He + nat-Hg Reaction at 0.90 and 3.6 GeV

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

Chaotic Scattering in Heavy--Ion Reactions

We discuss the relevance of chaotic scattering in heavy--ion reactions at energies around the Coulomb barrier. A model in two and three dimensions which takes into account rotational degrees of freedom is discussed both classically and quantum-mechanically. The typical chaotic features found in this description of heavy-ion collisions are connected with the anomalous behaviour of several experimental data.Comment: 35 pages in RevTex (version 3.0) plus 27 PostScript figures obtainable by anonymous ftp from VAXFCT.CT.INFN.IT in directory kaos. Fig. 1 upon request to the authors. To be published in the October Focus issue on chaotic scattering of CHAO

EVOLUTION OF THE FUSION LIKE PROCESS AROUND THE FERMI ENERGY

The study of evaporation residue from the Ne + Ag system shows that there is qualitative change in the reaction mechanism in the Fermi energy domain. At 20 MeV/u the projectile is mostly absobered by the target, while at 30-37 MeV/u a continious range of mass transfer with a large transverse momentum is observed

Interprétation de fonctions d'excitation de réactions partielles 51V(p, n)51Cr à l'aide du modèle statistique

Partial cross-sections have been obtained between 2 and 4.6 MeV from measurements of the γ rays emitted in the 51V(p, n) reaction. They are compared with theoretical curves from an Hauser and Feshbach calculation using optical model parameters. Agreement occurred with some values of spin proposed for the first low-lying levels of 51Cr. Fluctuations around a smooth curve observed in the excitation functions are discussed.Les sections efficaces de différentes réactions partielles 51V(p, n) 51Cr ont été extraites de mesures du rayonnement γ accompagnant ces réactions. De 2 à 4,6 MeV, leur variation en fonction de l'énergie a été comparée aux courbes théoriques calculées d'après Hauser et Feshbach à l'aide de paramètres du modèle optique. Des indications concernant les spins et les parités des 5 premiers niveaux de 51Cr en ont été déduites. Les fluctuations de sections efficaces autour de la valeur moyenne sont discutées