Dynamic effects in electron-energy-loss processes in barium, lanthanum, and cerium

Electron-energy-loss spectra of barium, lanthanum, and cerium in the regions of $3d$-level excitations have been found to show doublet structures associated with each spin-orbit component. The relative intensities of the structures vary systematically with excitation energy. One of the doublet components can in each case be associated with a $3d\to 4f$ excitation. For the explanation of the second component we propose a process which involves decay of an intermediate screened $3d^{9}4f^2$ state.