Gamma ray multiplicity in the quasi-fission of Cu + Au at 443 MeV

Abstract

We have measured the γ-ray multiplicity associated with the quasi-fission of the system 63Cu + 197Au at 443 MeV lab. energy. Its value increases with the degree of inelasticity. The maximum values are 25 at 35° (corresponding to initial l-waves of about 150 ħ) and 22 at 49° (close to the grazing angle). Taking into account the angular momentum carried away by emitted particles and the deformation of the fragments at the scission point, these values agree with the sticking hypothesis. The possibility of additional angular momentum imparted to the fragments by the quasi-fission process itself is discussed. The γ-multiplicity associated with sequential fission has also been measured