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Quantum efficiency of opaque CsI photocathodes with channel electron multiplier arrays in the extreme and far ultravioletThe arrays are overcoated with a CsI photocathode in the VUV. The measurements are part of the development program for the Extreme Ultraviolet Explorer. Monochromatic light from a hollow cathode discharge source passing through a McPherson grazing incidence monochromator is used to illuminate the CsI photocathode. The beam diameter is kept small (approximately 2 mm) to confine it within the individual thickness strips. A bias grid is used to produce a 50-V/mm electric field to guarantee collection of all photoelectrons emitted by the CEMA (channel electron multiplier array) webbing. The CEMAs are operated with a gain of 2-3 x 10 to the 6th and are moderately saturated. A channeltron secondary transfer standard is used to determine the absolute QE in the EUV, whereas an NBS calibrated windowed photodiode is used to measure the FUV absolute QE. It is noted that the CsI gives a factor of 3 increase in the QE in the EUV and a factor of 50-5000 in the FUV.
Document ID
19830033165
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Martin, C.
(California Univ. Berkeley, CA, United States)
Bowyer, S.
(California, University Berkeley, CA, United States)
Date Acquired
August 11, 2013
Publication Date
December 1, 1982
Publication Information
Publication: Applied Optics
Volume: 21
Subject Category
Instrumentation And Photography
Accession Number
83A14383
Funding Number(s)
CONTRACT_GRANT: NASW-3636
Distribution Limits
Public
Copyright
Other

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