An
x-ray image intensifier (XRII) is an
image intensifier that converts
x-rays into visible light at higher
intensity than mere
fluorescent screens do. 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. The device contains a low absorbency/scatter input window, typically aluminum, input fluorescent screen, photocathode, electron optics, output fluorescent screen and output window. These parts are all mounted in a high vacuum environment within glass or more recently, metal/ceramic. By its
intensifying effect, It allows the viewer to more easily see the structure of the object being imaged than fluorescent screens alone, whose images are dim. The X-ray II requires lower
absorbed doses due to more efficient conversion of x-ray quanta to visible light. This device was originally introduced in 1948.