On the Macroscopic Limit of Nuclear Dissipation

The Landau-Vlasov equation is applied to a slab of width $L$. This geometry is introduced to simulate somehow the finiteness of real nuclei but to allow for analytical solutions, nevertheless. We focus on the damping of low frequency surface modes and discuss their friction coefficient. For this quantity we study the macroscopic limit as defined by $L\to \infty$. We demonstrate that the same result can be obtained for finite $L$ by applying an appropriate frequency smoothing, if only the smearing interval is sufficiently large. The apparent, but important consequences are discussed which this result will have for the understanding of the nature of dissipation in real nuclei.