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An X-ray image intensifier (XRII) is an image intensifier that converts X-rays into visible light at higher intensity than the more traditional fluorescent screens can. Such intensifiers are used in X-ray imaging systems (such as fluoroscopes) to allow low-intensity X-rays to be converted to a conveniently bright visible light output.
An image intensifier or image intensifier tube is a vacuum tube device for increasing the intensity of available light in an optical system to allow use under low-light conditions, such as at night, to facilitate visual imaging of low-light processes, such as fluorescence of materials in X-rays or gamma rays (X-ray image intensifier), or for conversion of non-visible light sources, such as ...
Input phosphor, when the X-rays interact with this piece, its energy is converted into a burst of visible light photons as they occur like this on the intensifying screen/monitor. The photocathode is a thin metal layer, that is usually composed of caesium and antimony compounds that respond to stimulation by the light with the emission of the ...
The electrons are drawn to the higher-voltage phosphor screen (green). Electrons that strike the phosphor screen cause the phosphor to produce photons of light viewable through the eyepiece lenses. OMNI, or OMNIBUS, refers to a series of contracts through which the US Army purchased GEN III night vision devices.
A circular cut of a PSP plate. On photostimulable phosphor (PSP) plates, the phosphor layer is typically 0.1 to 0.3 mm thick. After the initial exposure by short-wavelength (typically, X-ray) electromagnetic radiation, excited electrons in the phosphor material remain 'trapped' in 'colour centres' ("F-centers") in the crystal lattice until stimulated by the second illumination.
Internal metallisation as a protective screen against unwanted light sources There are two common photomultiplier orientations, the head-on or end-on (transmission mode) design, as shown above, where light enters the flat, circular top of the tube and passes the photocathode, and the side-on design (reflection mode), where light enters at a ...
The shadow mask is installed to the screen using metal pieces [348] or a rail or frame [349] [350] [351] that is fused to the funnel or the screen glass respectively, [256] holding the shadow mask in tension to minimize warping (if the mask is flat, used in flat-screen CRT computer monitors) and allowing for higher image brightness and contrast.
The reduced metal can be observed as a visible darkening of the phosphor layer. The darkening (and the brightness loss) is proportional to the phosphor's exposure to electrons and can be observed on some CRT screens that displayed the same image (e.g. a terminal login screen) for prolonged periods. [14]