Abstract

Hans Bethe in 1966 theoretically predicted the shadowlike diffraction effects in the forward (θ ≈ D – 1°) elastic scattering cross sections of low-energy electrons off atoms such as He, Ne, and Ar and explained them as being due to the coupling of inelastic scattering channels. By scattering 10-25-eV electrons off Ne in the forward direction (θ up to 20 mrad), Geiger and Moran¹ found the diffraction effects (superimposed on the Born approximation). This shadow diffraction occurs not at the atom edge (radius γ₀) but at the sheath surrounding (radius R) the atom due to agglomeration of the inelastic scattered electrons.

© 1987 Optical Society of America