X-ray fluorescence

https://doi.org/10.1351/goldbook.X06710
The emission of characteristic X-radiation by an atom as a result of the interaction of electromagnetic radiation with its orbital electrons.
Source:
PAC, 1994, 66, 2513. 'Nomenclature for radioanalytical chemistry (IUPAC Recommendations 1994)' on page 2526 (https://doi.org/10.1351/pac199466122513)