Cross sections and spin polarizations of electrons elastically scattered from oriented molecules (CH3I)

Abstract

Elastic differential cross sections and spin polarizations for electrons elastically scattered from CH3I are calculated using the independent atom model. Three molecular orientations with respect to the incident electron wavevector are considered — first, the molecule is oriented randomly, second, the electron wave front and molecular bond are parallel, and third, the wavefront and the bond axis are perpendicular. It will be seen to what extent orientational averaging weakens features of the cross section and spin polarization. The calculations show that cross section and spin polarization measurements are a possible tool for determining the degree of molecular orientation. There is no degeneracy betweenI–C andC–I in cross section and spin polarization measurements. The results presented here for 200 eV and 600 eV electrons scattered by CH3I should be considered as a case study and it should be possible to find molecules and electron energies for which even more dramatic differences between the various orientations between the molecules and the electrons can be expected.