Auger effect

The Auger effect is a phenomenon in physics in which two electrons are emitted from an atom. The first electron, coming from a lower and more stable energy level is emitted by excitation through a high-energy photon. The vacancy is then occupied by another electron from higher energy level, releasing energy to another electron. This third electron is then ejected from the atom, just like the first.

The phenomenon is slightly similar to the photoelectric effect.