Combined Electron Excitation and X-Ray Excitation for Spectrometry in the SEM

Energy-dispersive X-ray spectrometry (EDS) is an analytical technique used to determine elemental composition. It is a powerful, easy-to-use, non-destructive technique that can be employed for a wide variety of materials. In this technique the electron beam of the scanning electron microscope (SEM) impinges on the sample and excites atomic electrons causing the production of characteristic X rays. These characteristic X rays have energies specific to elements in the sample. The EDS detector collects these X rays as a signal and produces a spectrum. Samples also can be excited by X rays. Collimated and focused X rays from an X-ray source produce characteristic X rays that can be detected by the same EDS detector. When X rays are used as the source of excitation, the method is then called X-ray fluorescence (XRF) or micro-XRF.