The Scattering of Fast Electrons in Gases

Abstract

The angular distribution of elastically scattered electrons of energies between 49.5 and 87.7 Kev has been measured in argon, neon, and helium over the range 0.3° to 6°. Comparison of the results with the theoretical curves calculated from the Hartree functions with the "Born approximation" shows good agreement in the case of argon, and in neon except at the smallest angles, but there is no agreement at all in the case of helium. The discrepancies are very similar to those found at the smallest angles in studies of scattering of electrons of a few hundred volts energy, and it is felt that the explanation in terms of polarization of the atomic field by the passing electron may be accepted here also.