The microanalysis of nonconductive specimen in a scanning electron
microscope is limited by charging effects. Using a charge density model
for the electric field buildup in a nonconductive specimen irradiated
by electrons, a Monte Carlo simulation method has been applied to
alumina (Al2O3). The results show a change in the
depth distribution for characteristic and bremsstrahlung X-ray,
φ(ρz) curves, and ψ(ρz) curves
(with absorption) for both elements' Kα lines. The
influence of the electric field on the measured X-ray intensity is
shown. The dependency of this influence by the three parameters,
electron energy, X-ray energy, and charge density, is clarified.