Straggling of fast electrons

Abstract

AbstractThe energy losses of fast electrons vary because of the stochastic nature of the interactions. In order to describe these processes and calculate the spectra of the total energy loss (straggling spectra), Monte Carlo simulations of fast electrons traversing a thin silicon absorber have been used. The distribution functions needed are described by the electronic energy losses in single collision calculated by Bichsel. Comparison between straggling spectra calculated on the basis of the single collision spectrum and that from its first moment (very often ‘stopping power’ in the literature), shows that the latter, the so‐called ‘Continuous Slowing Down Approximation (CSDA),’ is a poor approximation in its description of the individual energy deposition. Copyright © 2006 John Wiley & Sons, Ltd.