A
gas-filled X-ray detector in which gas amplification reaches
saturation and proportionality no longer exists. The output signal does not depend on the incident
energy. The time taken for the counter to recover from the
saturation is called
dead time.
Source:
PAC, 1995, 67, 1745
(Nomenclature, symbols, units and their usage in spectrochemical analysis-XI. Detection
of radiation (IUPAC Recommendations 1995))
on page 1754