Dynamical analysis of deep inelastic interactions in a light composite system (19F +14Mg) at about 1.3 MeV/u above the Coulomb barrier

Abstract

A dynamical model using three collective degrees of freedom: (r) — the distance between the center-of-mass of the nuclei, (gq) — the deflection angle and (x) — the mass-asymmetry, was applied to analyse deep inelastic collisions in a light cpmposite system19F(72 MeV) +14Mg. Two kinds of nuclear potentials, a proximity and a Woods-Saxon one, have been chosen to describe the nuclear interaction. To obtain a good prediction of the 1-critical values for fusion and a good description of the experimental angular distributions it was necessary to use much larger values of the coefficients for the friction tensor, as compared to the case of heavy composite systems. By comparing with experimental angular distributions it resulted that deep inelastic collisions in such light composite system correspond to a dissipated energy higher than 5 MeV. In the Wilczynski plots for such light composite system at about 1.3 MeV/u above the Coulomb barrier, a mixing of quasielastic and deep inelastic components was found in agreement with the experimental energy spectra. Based on theQ gg systematics, the calculated cross-sections d2 σ/dgq dA forA=16 gave a good estimation of the experimental angular distribution for theZ=8 element.