In the past, several researchers have added X-Ray Fluorescence (XRF) to SEMs, using the standard Energy-Dispersive Spectrometers (EDS) already in place -. Most used the electron beam to create fluorescing x rays with a thin transmission target placed between the beam and the sample. The main problem with this approach was the low incident x-ray flux onto the sample, especially if the analysis area is restricted. The advantages of XRF (e.g., improved sensitivities and peak-to-background ratios) were then lost because of the low count rates achieved. We solved this problem by attaching a separate x-ray source onto the SEM, with flux outputs orders of magnitude higher than those produced by SEM beams in transmission targets. By restricting the sample analysis area with apertures or active focusing optics, one can still achieve count rates in these small areas that are typical of standalone XRF spectrometers, with all the advantages of the XRF technique .