Quality Assurance / Quantum efficiencies
 
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Quantum efficiencies

The detection efficiency of a CEM with respect to a particle is defined as the probability of this particle or photon producing an output pulse.

While all other characteristics of the CEMs can be measured with our facilities this is not possible for the detection efficiences because of the extreme difficulty and complexity of these measurement. Publised data reflect the considerable discrepancies and experimental difficulties involved in the measurements of detection efficiencies of glass CEMs (Fig. 1).

The necessity of specifying detection efficiencies results from the question whether measurements at a certain energy or wavelength range are reasonable and which order of magnitude the efficiency has in this range.

The detection efficiency curves for electrons, positive ions and UV light in Fig. 2 - 4 are based on published data and allow an approximate estimation of the efficiency in the given energy and wavelength range.

Literature:

- "Channel electron multipliers" (first book) in ACTA ELECTRONICA, Vol. 14, 1/1971

- "Channel electron multipliers" (second book) in ACTA ELECTRONICA, Vol 14, 4/1971

- Edward A. Kurz, Channel electron multipliers, American Laboratory, March 1979

- Elektronenvervielfacher-Kanäle und -Kanalplatten, Ausgabe September 1976, VALVO

- CHANNELTRON Electron Multiplier Handbook for Mass Spectrometry Applications, GALILEO

- DATA HANDBOOK, Electron Multipliers, PC12, 1991, Philips Photonics

 

 

 

 

 

 

 

 

 

 

 

 

 

 
 
         
Fig. 2 Detection efficiency for electrons   Fig. 3 Detection efficiency for positive ions   Fig. 4 Detection efficiency for UV light
         

 

 

 

 
Fig. 1 Detection efficiency for electrons
1: F. Bordoni, N.I.M. 97 - 405 (1971)
2: G. Paschmann, et al., R.S.I. 41 - 12 (1970)
3: L.A. Franck, R.S.I. 40 - No 2 (1969)
4: J.R. Sharber et al, IEEE NS 15 (3) (1968)
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


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