Photoelectric Image Intensifiers

For application in spectroscopy the following characteristic properties of image intensifiers are important  

The collection efficiency can be enhanced when a thin mica window is used to support the phosphor screen, and photographic contact prints of the image are made. Another way is the use of fiber-optic windows. 

The spatial resolution depends on the imaging quality which is influenced by the thickness of the phosphor-screen photocathode sandwiches, by the homogenity of the magnetic field, and by the lateral velocity spread of 

Such intensified OMA systems are commercially available and are extremely useful for lower-level light detection of extended spectral ranges [4.138,139]. Their advantages may be summarized as follows  

The resolution is highest at the center of the screen and decreases towards the edges. Table 4.2 compiles some typical data of a commercial three-stage image intensifier [4.78], 

Type Useful diameter [mm] Resolution [line pairs/mm] Gain 

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The particle nature of light was postulated in 1905 by Einstein to explain the photoelectric effect. When light is incident on a metal surface in an evacuated tube, electrons may be ejected from the metal. This is the operational basis of photomultipliers and image intensifies, which transform light to an amplified electric signal (see Section 3.1). 

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