Depth Profiling Using Proton Induced X-Rays: The Influence of Experimental and Theoretical Uncertainties

The mean depth (a), the mean width (b) and the relative concentration (c) of an unknown distribution of foreign atoms in bulk material can be determined by relative x-ray yield measurements. It is shown by means of a set of case studies for rectangular distributions of foreign Cu-atoms in Ag-bulk to which extent experimental x-ray yield errors, and errors in the theoretical description of the x-ray production process and the stopping of projectiles contribute to errors in the result. The theoretical description uses the ECPSSR theory and takes experimental deviation from this theory, energy loss straggling and multiple scattering into account.