Scattering of Fast Electrons in Hydrogen

Abstract

Electrons of 2000-volt energy scattered by hydrogen molecules are found to be divided into two distinct groups, those scattered elastically and those scattered inelastically. The former have been scattered by the nuclei, while the latter have been scattered by the atomic electrons. The theoretical ratio of the number inelastically scattered to the number elastically scattered differs according to whether one adopts the classical theory of scattering or the wave mechanical. The difference comes in through the fact that when particles are scattered by similar particles, such as electrons by electrons, the two theories lead to different expressions. The experimental results are in much closer agreement with the predictions of the wave mechanical theory than with those of the classical theory. A slight difference between the results obtained with helium and those obtained with hydrogen may be attributed to diffraction effects which are present when scattering is due to diatomic molecules.