The Auger effect or Auger−Meitner effect is a physical phenomenon in which the filling of an inner-shell vacancy of an atom is accompanied by the emission of an electron from the same atom.[1] 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. Although most often this energy is released in the form of an emitted photon, the energy can also be transferred to another electron, which is ejected from the atom; this second ejected electron is called an Auger electron.[2]
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, KL1L2,3.
The effect was first discovered by Lise Meitner in 1922; Pierre Victor Auger independently discovered the effect shortly after and is credited with the discovery in most of the scientific community.[3][4]
Upon ejection, the kinetic energy of the Auger electron corresponds to the difference between the energy of the initial electronic transition into the vacancy and the ionization energy for the electron shell from which the Auger electron was ejected. These energy levels depend on the type of atom and the chemical environment in which the atom was located.
Auger electron spectroscopy involves the emission of Auger electrons by bombarding a sample with either X-rays or energetic electrons and measures the intensity of Auger electrons that result as a function of the Auger electron energy. The resulting spectra can be used to determine the identity of the emitting atoms and some information about their environment.
The Auger effect can impact biological molecules such as DNA. Following the K-shell ionization of the component atoms of DNA, Auger electrons are ejected leading to damage of its sugar-phosphate backbone.[5]
Discovery
The Auger emission process was observed and published in 1922 by Lise Meitner,[6] an Austrian-Swedish physicist, as a side effect in her competitive search for the nuclear beta electrons with the British physicist Charles Drummond Ellis.
The French physicist Pierre Victor Auger independently discovered it in 1923[7] upon analysis of a Wilson cloud chamber experiment and it became the central part of his PhD work.[8] High-energy X-rays were applied to ionize gas particles and observe photoelectric electrons. The observation of electron tracks that were independent of the frequency of the incident photon suggested a mechanism for electron ionization that was caused from an internal conversion of energy from a radiationless transition. Further investigation, and theoretical work using elementary quantum mechanics and transition rate/transition probability calculations, showed that the effect was a radiationless effect more than an internal conversion effect.[9][10]
^Akinari Yokoya & Takashi Ito (2017) Photon-induced Auger effect in biological systems: a review,International Journal of Radiation Biology, 93:8, 743–756, DOI: 10.1080/09553002.2017.1312670
^L. Meitner (1922). "Über die Entstehung der β-Strahl-Spektren radioaktiver Substanzen". Z. Phys. 9 (1): 131–144. Bibcode:1922ZPhy....9..131M. doi:10.1007/BF01326962. S2CID 121637546.
^P. Auger: Sur les rayons β secondaires produits dans un gaz par des rayons X, C.R.A.S. 177 (1923) 169–171.
^Duparc, Olivier Hardouin (2009). "Pierre Auger – Lise Meitner: Comparative contributions to the Auger effect". International Journal of Materials Research. 100 (9): 1162–1166. Bibcode:2009IJMR..100.1162H. doi:10.3139/146.110163. S2CID 229164774.
^"The Auger Effect and Other Radiationless Transitions". Burhop, E.H.S., Cambridge Monographs on Physics, 1952
^"The Theory of Auger Transitions". Chattarji, D., Academic Press, London, 1976
March 04, 2023
auger, effect, auger, meitner, effect, physical, phenomenon, which, filling, inner, shell, vacancy, atom, accompanied, emission, electron, from, same, atom, when, core, electron, removed, leaving, vacancy, electron, from, higher, energy, level, fall, into, vac. The Auger effect or Auger Meitner effect is a physical phenomenon in which the filling of an inner shell vacancy of an atom is accompanied by the emission of an electron from the same atom 1 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 Although most often this energy is released in the form of an emitted photon the energy can also be transferred to another electron which is ejected from the atom this second ejected electron is called an Auger electron 2 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 KL1L2 3 Contents 1 Effect 2 Discovery 3 See also 4 ReferencesEffect EditThe effect was first discovered by Lise Meitner in 1922 Pierre Victor Auger independently discovered the effect shortly after and is credited with the discovery in most of the scientific community 3 4 Upon ejection the kinetic energy of the Auger electron corresponds to the difference between the energy of the initial electronic transition into the vacancy and the ionization energy for the electron shell from which the Auger electron was ejected These energy levels depend on the type of atom and the chemical environment in which the atom was located Auger electron spectroscopy involves the emission of Auger electrons by bombarding a sample with either X rays or energetic electrons and measures the intensity of Auger electrons that result as a function of the Auger electron energy The resulting spectra can be used to determine the identity of the emitting atoms and some information about their environment Auger recombination is a similar Auger effect which occurs in semiconductors An electron and electron hole electron hole pair can recombine giving up their energy to an electron in the conduction band increasing its energy The reverse effect is known as impact ionization The Auger effect can impact biological molecules such as DNA Following the K shell ionization of the component atoms of DNA Auger electrons are ejected leading to damage of its sugar phosphate backbone 5 Discovery EditThe Auger emission process was observed and published in 1922 by Lise Meitner 6 an Austrian Swedish physicist as a side effect in her competitive search for the nuclear beta electrons with the British physicist Charles Drummond Ellis The French physicist Pierre Victor Auger independently discovered it in 1923 7 upon analysis of a Wilson cloud chamber experiment and it became the central part of his PhD work 8 High energy X rays were applied to ionize gas particles and observe photoelectric electrons The observation of electron tracks that were independent of the frequency of the incident photon suggested a mechanism for electron ionization that was caused from an internal conversion of energy from a radiationless transition Further investigation and theoretical work using elementary quantum mechanics and transition rate transition probability calculations showed that the effect was a radiationless effect more than an internal conversion effect 9 10 See also EditAuger therapy Charge carrier generation and recombination Characteristic X ray Coster Kronig transition Electron capture Radiative Auger effectReferences Edit IUPAC Compendium of Chemical Terminology 2nd ed the Gold Book 1997 Online corrected version 2006 Auger effect doi 10 1351 goldbook A00520 IUPAC Compendium of Chemical Terminology 2nd ed the Gold Book 1997 Online corrected version 2006 Auger electron doi 10 1351 goldbook A00521 Grant John T David Briggs 2003 Surface Analysis by Auger and X ray Photoelectron Spectroscopy Chichester IM Publications ISBN 1 901019 04 7 Matsakis Demetrios Coster Anthea Laster Brenda Sime Ruth 2019 09 01 A renaming proposal The Auger Meitner effect Physics Today 72 9 10 11 Bibcode 2019PhT 72i 10M doi 10 1063 PT 3 4281 ISSN 0031 9228 S2CID 202939712 Akinari Yokoya amp Takashi Ito 2017 Photon induced Auger effect in biological systems a review International Journal of Radiation Biology 93 8 743 756 DOI 10 1080 09553002 2017 1312670 L Meitner 1922 Uber die Entstehung der b Strahl Spektren radioaktiver Substanzen Z Phys 9 1 131 144 Bibcode 1922ZPhy 9 131M doi 10 1007 BF01326962 S2CID 121637546 P Auger Sur les rayons b secondaires produits dans un gaz par des rayons X C R A S 177 1923 169 171 Duparc Olivier Hardouin 2009 Pierre Auger Lise Meitner Comparative contributions to the Auger effect International Journal of Materials Research 100 9 1162 1166 Bibcode 2009IJMR 100 1162H doi 10 3139 146 110163 S2CID 229164774 The Auger Effect and Other Radiationless Transitions Burhop E H S Cambridge Monographs on Physics 1952 The Theory of Auger Transitions Chattarji D Academic Press London 1976 Retrieved from https en wikipedia org w index php title Auger effect amp oldid 1136315679, wikipedia, wiki, book, books, library,
