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Bethe's stopping power equation:

The simplest way to calculate the energy loss of electrons during scattering processes in solids is the formula of Bethe's stopping power, in which the contribution of all possible excitation processes to the energy loss has been represented by a factor called the mean ionization energy. Representing all inelastic processes by one stopping power, the total energy loss of an electron for the path length S between two elastic scatterings is presented by:

 

with

 

An extension of the Bethe formula for energies less than the mean ionization energy J was published by Rao-Sahib and Wittry [RSW74]:

 

for energies less than .

The mean ionization potential implemented in SESAME is that from Zeller (1967 unpublished) which also has been used by Pouchou and Pichoir in the STRATA program:

The main disadvantage of the Bethe approach in Monte Carlo calculations is, that it is impossible to simulate excitation processes and the generation of secondary electrons.



Horst Wagner
Tue Mar 19 10:24:55 MET 1996