Fragment emission in Ca+Ca reactions at 25 MeV/nucleon, I. Lombardo, Univ. Federico II, Napoli and INFN-Sez. Napoli, Italy − We present experimental data concerning 40,48Ca+40,48Ca reactions at 25 MeV/nucleon.  The 4π multi-detector Chimera has been used as detection device.  Various effects due to the different neutron to proton ratios (N/Z) of entrance channels have been investigated.  First of all, strong isotopic effects are seen in inclusive emission of light fragments.  Moreover, Z and N distributions of light fragments are characterized by even-odd oscillations, whose amplitude seems to be related to the neutron richness of entrance channel.  In semi-peripheral collisions, isospin diffusion signals have been found.  They were investigated by analyzing isobaric emission (7Li/7Be) from quasi-projectile sources formed in the four studied systems. They claim for an incomplete charge equilibrium reached by the di-nuclear system during the interaction phase.  The emission of evaporation residues in semi-central collisions was also investigated.  We found that the N/Z degree of freedom plays an important role on the fate of hot quasi-fusion sources formed; in particular, the larger is the neutron content of entrance channels and the larger is the emission of evaporation residues.  Experimental data have been compared with CoMD-II model calculations, and we find that a moderately stiff symmetry potential have to be used to reproduce satisfactorily the data.