Fraction of Backscattered Electrons Depending on Sample Thickness  Practical Electron Microscopy and Database   An Online Book  

Microanalysis  EM Book https://www.globalsino.com/EM/  


=================================================================================  
As an examlpe of interaction between incident electrons and matters, Figure 1182a shows the fractions of the transmitted (η_{T}) and backscattered (η_{B}) electrons from some Al films with an incident electron beam at accelerating energies of 15 keV and 20 keV, respectively. Those fractions are thicknessdependent. The data was obtained with Monte Carlo calculations. [1] It is reasonable that the fraction of transmitted electrons at higher voltages (20 keV) is much larger than that at lower voltages (15 keV).
Figure 1182b shows the fraction of backscattered electrons at different accelerating voltages of incident electron beam obtained by Monte Carlo modeling from some materials.
Figure 1182c shows the fractions of saturated backscattered electrons in aluminium (Al), titanium (Ti) and silver (Ag) as a function of accelerating voltages at normal incidence. These profiles indicate that their fractions are highly materialdependent and decrease with the increase of the accelerating voltage.
[1] R Shimizu, Y. Kataoka, T. Ikuta, T. Koshikawa and H. Hashimoto, A Monte Carlo approach to the direct simulation of electron


=================================================================================  

