Electron Energy Losses in Cylindrical Cavities: Nonlocal Effects

In the framework of the dielectric theory, we present the electron energy loss probability distribution calculated for a fast probe near cylindrical surfaces using a non-local dielectric function. The small size of the drilled holes in experiments and electron trajectories close to the interface make necessary the introduction of dispersion effects when describing the energy loss spectra. We compare the results to those given by the local Drude model. The k-dependence of the dielectric function allows us to discuss energy losses in inhomogeneous media when using an effective medium dielectric function.