Observed radiation from surface plasmons in aluminum
Plasma radiation from thin films of aluminum bombarded by non-normally incident 80 keV electrons has been investigated. Radiative decay of both volume plasmons and surface plasmons was observed with the surface plasmon radiation being very sensitive to contamination of the film surface by an oxide layer. The surface resonance occurs at 10.2 eV, whereas the volume resonance is at 15 eV. These values are in accord with electron energy-loss experiments.