Transition radiation from rough surfaces

The light emission of normally incident 77 keV electrons on silver surfaces of different roughness has been investigated. The roughness was quantitatively determined by measuring the scattered light of a normally incident laser beam. In addition to the transition radiation, which is expected for smooth surfaces, light emission of surface plasmons via surface roughness occurs. The shape and the intensity of the spectral distribution of this emission show a characteristic change with the surface roughness.