## gain, $$G$$

of a photomultiplier
https://doi.org/10.1351/goldbook.G02572
The gain of a @P04626@ is given by the equation $$G=k\ \sigma ^{n}$$, where $$k$$ is the efficiency of @C01148@ of photoelectrons on the first dynode, $$\sigma$$ is the secondary emission ratio, i.e. the number of secondary electrons emitted for each electron incident on the dynode and $$n$$ is the number of dynodes.
Source:
PAC, 1995, 67, 1745. (Nomenclature, symbols, units and their usage in spectrochemical analysis-XI. Detection of radiation (IUPAC Recommendations 1995)) on page 1753 [Terms] [Paper]