The treatment of heavy-ion collisions by Langevin equations

Fusion and deep-inelastic heavy-ion collisions are treated by Langevin equations within the framework of the surface friction model. Cross sections are calculated by Monte Carlo sampling of trajectories. An important result is that in contrast to what is usually assumed statistical fluctuations play a significant role in analysing heavy ion fusion data. It is demonstrated that in the analysis of deep-inelastic collisions the Langevin-Monte-Carlo method is more accurate than solving the corresponding Fokker-Planck equation by the usual moment expansion with the assumption of a gaussian distribution function.