Editing Auger effect (section)

{{short description|Physical phenomenon}}
[[File:Auger Process.svg|thumb|340px|Two views of the Auger process. (a) illustrates sequentially the steps involved in Auger deexcitation. An incident electron (or photon) creates a core hole in the 1s level. An electron from the 2s level fills in the 1s hole and the transition energy is imparted to a 2p electron which is emitted. The final atomic state thus has two holes, one in the 2s orbital and the other in the 2p orbital. (b) illustrates the same process using [[X-ray notation]], KL<sub alt="KL_1L_{2,3}">1</sub>L<sub>2,3</sub>.]]
The '''Auger effect''' ({{IPAc-en|oʊ|ˈ|ʒ|eɪ}}; {{IPA|fr|ˈ/o.ʒe/}}) or '''Auger−Meitner effect''' is a physical phenomenon in which [[atom]]s eject [[electrons]]. It occurs when an [[inner-shell electrons|inner-shell]] vacancy in an [[atom]] is filled by an electron, releasing energy that causes the emission of another electron from a different shell of the same atom.<ref>{{GoldBookRef|title=Auger effect|file=A00520}}</ref>

When a [[core electron]] is removed, leaving a vacancy, an electron from a higher energy level may fall into the vacancy, resulting in a release of [[energy]]. For light atoms (Z<12), this energy is most often transferred to a valence electron which is subsequently ejected from the atom.<ref name="Photoabsorption">{{cite book |last1=Berkowitz |title=Photoabsorption, Photoionization, and Photoelectron Spectroscopy |publisher=Academic Press |isbn=978-0-12-091650-4 |page=156 |doi=10.1016/B978-0-12-091650-4.50011-6 }}</ref> This second ejected electron is called an '''Auger electron'''.<ref>{{GoldBookRef|title=Auger electron|file=A00521}}</ref> For heavier atomic nuclei, the release of the energy in the form of an emitted [[photon]] becomes gradually more probable.