Energy Dispersive X-Ray Spectroscopy (EDX)
Energy dispersive X-ray spectroscopy is a method for elemental analyses. Therefore the electron beam is focused onto the sample. The energy of the electron beam is high enough to remove electrons from the core shells, i.e. to ionize atoms of the sample. If the incident beam removes an inner shell electron an electron from an upper shell will take its former position. This electron from the upper shell has a higher energy then the electron in the inner shell. The energy difference between them will be released as X-Rays, which are specific for each element according the Pauli principle.
The EDX detector now can measure the number and the energy of emitted X-rays. The operator can now determine the elemental structure of the sample.