Pre-equilibrium emission and clustering in ${}^{81}Rb$ from ${}^{16}O+{}^{65}Cu$ and ${}^{19}}F+{}^{62}Ni$ at 16 MeV/A.

Mantovani G., Fabris D., Gramegna F., Marchi T., Cicerchia M., Cinausero M., Mabiala J., Appannababu S., Degerlier M., Fotina O.V., Kravchuk V.L., Baiocco G., Barlini S., Bini M., Bruno M., Casini G., D'Agostino M., Gelli N., Morelli L., Olmi A., Pasquali G., Piantelli S., Poggi G., Valdrè S., Vardaci E.
  Mercoledì 28/09   10:00 - 13:00   Edificio Psicologia 2 - Aula 3F   I - Fisica nucleare e subnucleare
Nuclear clustering has been studied since a long time. Recently a large interest has been re-addressed to this phenomenon, in particular to the study of nuclear states built on clusters bound by valence neutrons at the drip-line, where clustering might be the favorite structural mode. In the last few years, several experiments were performed at LNL to investigate cluster structure effects in the nuclear matter, as the comparative study of pre-equilibrium emission from nuclear composite systems populated by different combination of $\alphai$-conjugated and non--$\alpha$-conjugated projectile and target nuclei. In particular, we will report here the study of the ${}^{16}O+{}^{65}Cu$ and ${}^{19}F+{}^{62}Ni$ reactions leading to the same compound nucleus ${}^{81}Rb^{*}$. The ${}^{16}O$ ($\alpha$-conjugated) and ${}^{19}F$ (non--$\alpha$-conjugated) beams were provided by the TANDEM-ALPI acceleration complex. The same bombarding energy per nucleon (16 MeV/A) has been used since the pre-equilibrium emission is expected to be mostly dependent on the projectile velocity. The used experimental setup is the GARFIELD + RCo detection array, fully equipped with digital electronics. After the particles identification and energy calibration, a preliminary analysis has shown an $\alpha$-particle overproduction with respect to what expected from predictions based on Hybrid Exciton model. In this presentation we will discuss a further comparison between the experimental data and the simulated results obtained using the pure statistical model code GEMINI++, the dynamical code TWINGO coupled with GEMINI++ and the AMD coupled with GEMINI++.