5. Fluorescence efficiencies

5.1 Definition

Consider an atom ionized in the X layer (X = K, L ₁ , L ₂ , etc.). Ionization has released an atomic electron; photo-ionization in particular corresponds to a photoelectron. But the atom's electron chain is reorganized with the emission of radiation (X-ray fluorescence in the case of photoionization) and also with the emission of electrons known as "Auger electrons", in reference to the work of Pierre Auger (Auger effect). The fluorescence yield ω _X for the X layer is defined as the probability that an electron gap created in the X layer will be filled by an electron, giving rise to a radiative transition.

However,...