Stochastic semi-classical description of fusion at near-barrier energies

Fusion reactions of heavy ions are investigated by employing a simple stochastic semi-classical model, which includes coupling between the relative motion and low frequency collective surface modes of colliding ions similarly to the quantal coupled-channels description. The quantal effect enters into the calculation through the initial zero-point fluctuations of the surface vibrations. A good agreement with results of coupled-channels calculations as well as experimental data is obtained for fusion cross sections of Ni isotopes. The internal excitations in nonfusing events as well as the fusion time are investigated.