Observation of the Compton modified band for the scattering of keV electrons by H2, He, Ne, and Ar

Measurements of the energy loss spectrum using keV electrons scattered from H2, He, Ne, and Ar at large scattering angles which define a portion of the Bethe surface are reported. The results are in good agreement with the theory of the Compton effect where the incident x-ray is replaced by a high-energy electron. The angular dependence of the inelastic scattering from H2, He, and Ne with 45 keV incident electrons is found to be in agreement with the first Born approximation including interference and exchange effects assuming weakly bound target electrons. The ratio of the inelastic peak height to the elastic peak height is compared with the results of the binary encounter theory using Hartree-Fock ground state wavefunctions and the results of experiment and theory are found to be in agreement within experimental uncertainties.