When and how are fragments formed in heavy ion collisions?

Employing the Quantum Molecular Dynamics approach for simulating the fragment formation in nucleus nucleus collisions we test the predictive power of the recently advanced Early Cluster Recognition Algorithm. We find that this algorithm gives almost the same number of fragments as the standard minimum spanning tree procedure. It is applicable not only to the late stage of the reaction. Taking advantage of this fact we find that the final fragmentation pattern is already realized shortly after the initial phase of violent collisions between the projectile and target nucleons, long before they are supposed to be formed in thermal models.