Observables for 2p photoionization

The special role of 2p photoionization in magnesium originates in the simplicity of the system which, however, is still complicated enough to exhibit typical electron-electron interactions. The main advantages are the following  

the emission of Lj-MjMj Auger electrons is isotropic, while that of Auger electrons has an angular distribution coefficient proportional to the alignment parameter. Therefore, a measurement of (Lj-N Mj) is equivalent to a determination of the alignment of the photoionized state, and this quantity can be included in the list of observables in 2p photoionization of magnesium. 

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