Determination of Electron Polarization by Means of Mott Scattering

The results of a numerical calculation of the polarization asymmetry factor, $S\left(\theta \right)={\left[\delta \right(\theta \left)\right]}^{\frac{1}{2}}$, and the single scattering cross section for the scattering of electrons by the unscreened Coulomb fields of gold and aluminum at energies of 75 kev and 121 kev are presented. The results for gold at 121 kev are compared with the Mohr and Tassie calculations for the same element and energy which include the effects of screening. This comparison (indicating a Mott asymmetry about 50% greater for the screened field at angles near 165°) suggests the desirability of more detailed investigation of screening effects in order to be confident of Mott scattering as a means of measuring the polarization of electrons in this energy region.