Critical evolution of hot van der Waals droplets

The dynamical evolution and fragmentation of a hot finite van der Waals system is investigated in a classical molecular dynamics approach. It is demonstrated that, under certain conditions determined mainly by the initial deposited energy, the fragmentation of rare-atom clusters exhibit a critical behavior. This behavior leaves its signatures in the mass distributions and the conditional moments, as well as the scaled factorial moments of the produced fragments. The connection between the observed critical behavior and the second-order liquid-gas phase transition is investigated by employing Fisher's droplet model for the average fragment mass distributions, and performing Campi and intermittency analysis for the correlation and fluctuation properties of the fragment mass distributions. The size dependence of the signatures of critical behavior is discussed. (C) 1997 American Institute of Physics.