Electron energy loss spectroscopy (EELS) involves the exposure of the sample to a focussed beam of monoenergetic electrons, typically < 3keV. As these electrons interact with the material some of them will undergo inelastic scattering whereby they lose some kinetic energy. In reflection electron energy loss (REELS) the electrons that are both eleatically and inelastically scattered are collected using the electron energy analyser. The low-energy electron energy loss spectrum (up to ~50eV in energy loss) contains the elastic, or zero-loss, peak as well as the plasmon peaks. This spectrum can be used to determine information about the band structure and dielectric properties of the sample.
Where the AXIS Supra+ is configured with the 10 keV FE-electron source for Auger electron spectroscopy, REELS can be added as an additional capbility. Alternatively an optional static electron source can be added to provide the REELS capability.