Aperture effects and the multiple-scattering problem of fast electrons in electron-energy-loss spectroscopy

Abstract
The effects of an angle-limiting aperture on electron-energy-loss spectra are studied for parallel and convergent incident beams. The angular distribution of multiply scattered electrons is calculated by means of Bessel functions. The residual intensity of multiple scattering after deconvolution is calculated. The influence of a cutoff angle for plasmon excitation to deconvolution and simulation is investigated showing that the cutoff effect reduces the accuracy of deconvolution, but if the angle-limiting aperture is much larger than the characteristic scattering angle the relative error in the deconvolution is less than 3%.