Calculation of Precision Measure and Effect of the Sample Crystallographic Orientation on the Charge Kinetics of MgO Single Crystals Subjected to keV Electron Irradiation

This study is performed with a dedicated scanning electron microscope (SEM) which allows the injection of few electrons doses in a large domain of energies and the measures of the secondary electron emission and the induced current created in the sample holder by the charges generated in the sample. In this paper, we present a detailed calcul of the precision measure on the intrinsic Secondary Electron Emission yield σ₀ and the stationary electron emission σ_st of magnesium oxide (MgO) single crystals of different crystalline orientation (100), (110) and (111)_. We notice that the precision measure becomes more and more excellent with increasing n (n is the number of equal time intervals Δt in which the measure of the induced and secondary currents is carried). The results shown that the crystalline orientation has a significant influence on intrinsic secondary electron emission σ₀ at low energies below 7 keV, but for high energies, the loss function of energy extending more deeply, the secondaries are dispersed before their release.