Secondary electron production and transport mechanisms by measurement of angle-energy resolved cross sections of secondary and backscattered electron emission from gold.

摘要

This work provides information about interactions that produce emitted electrons from polycrystalline gold. Emission energy-angle-dependent electron spectra from a polycrystalline Au surface have been measured at several incident electron beam energies. The range of incident energies (~100 eV to 2500 eV) extends from below the first crossover energy, through Emax, to above the second crossover energy. The conventional distinction between secondary electrons (SE) (50 eV) and backscattered electrons (BSE) (>50 eV) is found to be crude for the investigation of electron yields using these energy-angle-resolved measurements. A more realistic boundary occurs at the local minima of the emission spectra; this feature is studied as a function of incident energy and emission angle. In addition, deviations observed in the angular resolved emission spectra from isotropic behavior suggest that residual signatures exist in the emission spectra resulting from the anisotropic SE production mechanisms. Based on the disparity between our observations and recent modeling of the emission spectra, the most recent theory and simulation studies may overestimate the occurrence of randomizing collisions of scattered secondary electrons in the model of the transport mechanism. Finally, description of extensive modification to instrumental and analysis methods are described, and their effectiveness is evaluated.