4.2 Characteristic emission peaks

The main interaction of the excitation radiation with the matter is the ionization of its atoms. Whenever the energy of the excitation radiation is large enough as to produce the ionization, the emission of characteristic radiation by the elements present in the sample will occur. However, the characteristic emission will be detected only if the efficiency of the detector is high. This emission will be detected as peaks in the measured spectrum.

There might be other peaks in the measured spectra which do not correspond to elements present in the sample itself. Part of the excitation radiation can reach some parts of the measuring chamber after being scattered at the sample and excite the elements present on such construction parts. These peaks are often referred to as 'spurious' peaks or instrument background.