Elastic-peak electron spectroscopy experiments

We turn now to determinations of IMFPs from elastic-peak electron spectroscopy (EPFS) experiments. This approach, which combines measurements of the elastically backscattered intensity from a surface and MC simulations for the same experimental conditions, provides a convenient means for obtaining IMFPs for many materials that can be compared with values calculated from optical data [49, 63-66]. The samples are typically sputtered both to clean the surfaces and to ensure that crystalline order is substantially removed (in order to avoid diffraction effects) it is important to choose an ion species and a large-enough ion energy so that the depth of the amorphized region is at least as large as the EPES sampling depth [67]. 

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