Channel Electron Multiplier (CEM)
Dispositif multiplicateur d'électrons
Channeltron® is a registered trade mark of Photonis – Burle – Galileo.
The channeltron compacts the design of the electron multiplier into a single component shaped like a cornucopia.
Its inside is coated with a thin film of semi-conducting material that has both a high secondary
electron emission coefficient, and a high resistance, so that the functions of secondary-emission and
voltage-division are merged. When a negative high voltage is applied at the wider input end, and a
positive voltage near ground is applied at the narrower output end, the resistive surface forms a continuous dynode.
A particle or a photon striking the funnel-shaped input aperture produces secondary electrons that are
accelerated down the channel by the positive bias. Upon striking the interior surface of the channel
walls, these electrons then generate further secondary electrons. The resulting avalanche process
produces an easily detectable output pulse of charge containing up to 10e8 electrons. At the destination
end a separate electrode (anode) collects the multiplied electrons.
Thanks to their low mass and high gain, CEM's are used in many nuclear physics labs and space
applications to count electrons and charged particles in pulse mode operation. Typical applications
include mass spectrometry, plasma analysis, Auger, electron spectrometers, and leak detectors.
See also • Voir aussi • Siehe auch :
Channeltron 4879M &
Channel Electron Multiplier Tube
57 x 68 mm • 2" 2/10 x 2" 7/10
Le contenu de ce site est sous copyleft The content of this site is under copyleft Der Inhalt dieser Website steht unter Copyleft