Effect of the sample annealing temperature and sample crystallographic orientation on the charge kinetics of MgO single crystals subjected to keV electron irradiation

摘要

This paper focuses on the effect of sample annealing temperature and crystallographic orientation on the secondary electron yield of MgO during charging by a defocused electron beam irradiation. The experimental results show that there are two regimes during the charging process that are better identified by plotting the logarithm of the secondary electron emission yield, ln sigma , as function of the total trapped charge in the material Q(T). The impact of the annealing temperature and crystallographic orientation on the evolution of ln sigma is presented here. The slope of the asymptotic regime of the curve ln sigma as function of Q(T), expressed in cm(2) per trapped charge, is probably linked to the elementary cross section of electron-hole recombination, sigma(hole), which controls the trapping evolution in the reach of the stationary flow regime.