A scintillator coupled to a
photomultiplier tube. Incident X-ray photons are converted in the scintillator into bursts of
visible light photons, some of which fall on the photocathode and can be measured. For incident
photons having energies higher than the absorption edge of the elements contained
in the scintillator, an escape peak can be observed.
Source:
PAC, 1995, 67, 1745
(Nomenclature, symbols, units and their usage in spectrochemical analysis-XI. Detection
of radiation (IUPAC Recommendations 1995))
on page 1753