Channel electron multiplier

Article By:

Elston, Stuart B. Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee.

Last reviewed:January 2020

DOI:https://doi.org/10.1036/1097-8542.757252

A single-particle detector which in its basic form (Fig. 1) consists of a hollow tube (channel) of either glass or ceramic material with a semiconducting inner surface. The detector responds to one or more primary electron impact events at its entrance (input) by producing, in a cascade multiplication process, a charge pulse of typically 10⁴–10⁸ electrons at its exit (output). Because particles other than electrons can impact at the entrance of the channel electron multiplier to produce a secondary electron, which is then subsequently multiplied in a cascade, the channel electron multiplier can be used to detect charged particles other than electrons (such as ions or positrons), neutral particles with internal energy (such as metastable excited atoms), and photons as well. As a result, this relatively simple, reliable, and easily applied device is employed in a wide variety of charged-particle and photon spectrometers and related analytical instruments, such as residual gas analyzers, mass spectrometers, and spectrometers used in secondary ion mass spectrometry (SIMS), electron spectroscopy for chemical analysis (ESCA), and Auger electron spectroscopy. See also: Auger effect; Electron spectroscopy; Mass spectrometry; Secondary ion mass spectrometry (SIMS); Spectroscopy

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