Electron transmission measurements of electron mean free path in supported thin films from 1–5 keV

Measurements are made of the transmission of medium energy electrons through in vacuo deposited films in order to determine the inelastic electron mean free path as a function of energy. Films of Al, Ge and Au are deposited in small increments on 20–30 Å carbon substrates supported by “holey” carbon films. The no-loss electron current is measured for each thickness as a continuous function of incident energy in the range of 1–5 keV. Although this preliminary experiment does not result in a precise separation of elastic and inelastic scattering effects, the attenuation lengths estimated are in reasonable agreement with measured and calculated in-elastic mean free paths. Elastic scattering cross sections appear to be smaller than estimated by simple theory.