Auger effect

[3] For heavier atomic nuclei, the release of the energy in the form of an emitted photon becomes gradually more probable.

Following the K-shell ionization of the component atoms of DNA, Auger electrons are ejected leading to damage of its sugar-phosphate backbone.

[4] The Auger emission process was observed and published in 1922 by Lise Meitner,[5] 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[6] upon analysis of a Wilson cloud chamber experiment and it became the central part of his PhD work.

[7] High-energy X-rays were applied to ionize gas particles and observe photoelectric electrons.

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 1 L 2,3 .