J. A. Riveros

Comparison of Φ (ρz) Curve Models in EPMA

Several authors have proposed different models for the ionization distribution function Φ(ρz). This paper presents a comparison of three of the most successful models for Φ(ρz): Packwood and Brown’s Gaussian model including Bastin et al.’s and Riveros et al.’s versions, the quadrilateral model proposed by Sewell et al. and Pouchou and Pichoir’s model. In general, all the tested models showed similar performances. Finally the advantages of the models related to basic principles over the mathematically optimized ones are considered.

Simple Model for Surface Ionization in Electron Probe Microanalysis

A new model for surface ionization Φ(0) was developed from a theoretical basis approximating the energetic distribution of backscattered electrons by a delta distribution in the interval [1, U o ]. The expression obtained is compared with other models and with a set of experimental data.