An empirical calculation of the depth distribution of primary X-ray production

Abstract

The depth distribution of the primary X-ray production at normal electron incidence is calculated by using a simple empirical consideration of the multiple reflection of electrons at imaginary planes parallel to the specimen surface to describe the electron scattering in the target. The ionisation cross-section for the production of characteristic X-rays is described by the non-relativistic expression of Bethe (1930). The calculated distributions are compared with experimental results and also with some theoretical results of Monte Carlo calculations. The calculated depth distributions show a strong dependence on the excitation potential in accordance with the strong tracer effect found in experimental distributions. The present distributions are also applied to the calculation of the absorption correction, and the results are compared with those from other models.