Flow and multifragmentation of $^{24}$Mg + $^{27}$Al at intermediate energies

An elaborated investigation was done into the reaction mechanism of heavy ion collisions at intermediate energies of small nuclear systems. Experimental data measured with the Huygens detectors and IQMD simulations of \mgal at 45 and 95 \amev were analysed with respect to the impact-parameter selection, the in-plane flow and the IMF production at mid-rapidity.It was found that only the mid-central impact-parameter class could be identified effectively. The event-plane reconstruction and flow measurements were studied with IQMD and a GEANT detector simulation. This showed that the azimuthal-correlation method gives the best reconstruction. The experimentally measured in-plane flow was consistent with the balancing energy derived from literature of 114 $\pm$ 10 \amevp. The azimuthal correlations and polar-angle distributions of IMFs emitted at mid-rapidity were used to distinct between a dynamic scenario, i.e. IQMD, and a statistical scenario described by a simple decaying-source model. The IQMD simulations were in very good agreement with the experimental data and the decaying-source simulations were not, which shows that multifragmentation in these small systems is a dynamic process. Keywords: small nuclear systems, impact parameter, flow, dynamic multifragmentation