Multi-electron process in which an atom is left in an excited state following a photoionization or Auger electron process, so that the outgoing electron has a characteristic kinetic energy slightly less than that of the parent photoelectron.
Note: Shakeup peaks are usually observed within \(\pu{10 eV}\) of the parent peak. However, for gases where the background is low, shakeup peaks have been identified at kinetic energies up to \(\pu{100 eV}\) less than that of the parent peak.
See also: shakeoff
Source:
PAC, 2020, 92, 1781. 'Glossary of methods and terms used in surface chemical analysis (IUPAC Recommendations 2020)' on page 1830 (https://doi.org/10.1515/pac-2019-0404)