Backscattering of 10-100 keV electrons from thick targets

Experimental measurements of backscattering as a function of incident electron beam energy, angle of beam incidence and atomic number of scatterer, together with energy spectra of backscattered electrons, are discussed within the framework of a simple, qualitative theory. A semi-empirical expression for the variation of backscattering coefficient with angle of beam incidence is derived. Spectra integrated over energy and angle of take off also tabulated from experimental measurements for several elements. The use of the experimental data to derive backscattering corrections for X-ray elemental analysis, particularly at non-normal incidence, is briefly described.