A simple dead‐time correction for X‐ray counting systems

The dead time ( t ) of an X‐ray counting system may be readily determined to the nearest 0.4 μs by accurately measuring the counting rate per second ( R ) for any selected wavelength on two specimens, whose R values differ by a factor of approximately 10, at several tube or specimen currents. The R of the most intense specimen should cover the range up to 6 × 10 4 counts per second.\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm{t =}}\frac{{{\rm{a}}_{\rm{1}} {\rm{b - ab}}_{\rm{1}}}}{{{\rm{ab (a}}_{\rm{1}} {\rm{- b}}_{\rm{1}} {\rm{) - a}}_{\rm{1}} {\rm{b}}_{\rm{1}} {\rm{(a - b)}}}}, $$\end{document}where a and b are the R values of the two specimens at one current, and a 1 and b 1 the R values of the same specimens at another. The average t is determined from as many current pairs as possible. All counting rates ( R ) are thereafter corrected by the equation\documentclass{article}\pagestyle{empty}\begin{document}$$ R_ \circ = \frac{R}{{1.0 - tR}}, $$\end{document}where R 0 is the true and R the measured rates per second. R should not exceed about 6 × 10 4 . For energy‐dispersive detectors, the R values of Kα and Kβ peaks may be used from a single specimen and substituted for a and b in the above equation to obtain t .