Energy Analyzer for Electron Diffraction by Gases

A velocity analyzer has been constructed for use in the diffraction of fast electrons by gases as well as solids. The angular distributions of elastically and of inelastically scattered electrons are electrostatically separated and are simultaneously recorded on photographic plates. Coherent inelastic scattering patterns from ${\mathrm{CCl}}_4$ vapor and ${\mathrm{C}}_6{\mathrm{H}}_6$ vapor have been obtained.