The basic structure of image intensifier.

The working principle of the image intensifier is that the X-ray image is input to the input screen, which makes the photocathode excite photoelectrons. Under the high-voltage acceleration between the anode and the cathode and the focusing potential of the grid, the photoelectrons bombard the output screen. Therefore, the fluorescent image whose brightness is reduced by one tenth can be thousands or even tens of thousands of times stronger than the ordinary fluorescent screen.

The brightness of X-ray fluorescent screen is very weak, so it is not suitable to use TV camera for image capture directly. The most reasonable way is to use image intensifier to convert X-ray image into visible light image and increase its brightness thousands of times, then take a video.

Author:Yevette