Auger Effect
A non-radiative atomic process in which the filling of an inner-shell electron vacancy causes the ejection of a second outer-shell (Auger) electron.
Governing formula
E_Auger = E_K - E_L1 - E_L2,3
SI unit
eV (Electron-Volts)
In depth
When an inner-shell electron is removed, an outer electron drops down to fill the vacancy. Instead of emitting a X-ray photon, the released energy is transferred radiationlessly to another electron, ejecting it with characteristic kinetic energy.
Examples in the real world
Auger Electron Spectroscopy (AES) determining surface elemental composition in materials science.