Use of thorium as a target in electron-spin analyzers

Measurements of the effective Sherman function have been carried out for 10–100-keV spin-polarized electrons scattering from a thick thorium target in a retarding Mott analyzer. At 20 and 100 keV the dependence on the maximum energy loss accepted by the detector has been measured. Comparison is made with scattering from a 1250-Å gold film. Thorium is seen to have a Seff up to 30% higher than gold. This higher Seff can not only improve the figure of merit of a spin detector, but also lessen its sensitivity to instrumental asymmetries. Comparison is also made with preliminary theoretical results. Good agreement between theory and experiment is seen in the thorium Sherman function relative to that of gold.