Detailed explanation of the night vision device's technical capabilities
When electrons pass through the tube, the atoms in the tube will release similar electrons, the number of which is the original number of electrons multiplied by a factor (about a few thousand times), and the microchannel plate (MCP) in the tube can be used to complete this. Work. A microchannel plate is a miniature glass disk containing millions of tiny pores (microchannels) inside, made using fiber optic technology. The microchannel plate is under vacuum and metal electrodes are mounted on both sides of the plate. Each microchannel is about 45 times longer than it is wide, and works like an electronic amplifier.
When electrons from the photocathode strike the first electrode on the microchannel plate, the electrons are accelerated through the glass microchannel under the action of a high voltage of 5000 volts between the two electrodes. When electrons pass through a microchannel, thousands of electrons in the channel are released, a process called cascading secondary emission. In short, the original electrons hit the sides of the microchannel, and the excited atoms then shed more electrons. These new electrons also hit other atoms, creating a chain reaction in which a handful of electrons enter the microchannel and thousands exit. An interesting phenomenon is that the microchannels on the MCP have a slight tilt angle (about 5-8°), which is not only to induce electron collisions, but also to reduce the ion feedback and direct light feedback from the phosphor layer at the output.
The night vision images are famous for their weird green luster.
At the end of the image intensifier tube, electrons hit a phosphor-coated screen. The electrons maintain their relative positions as they pass through the microchannel, which ensures that the image remains intact because the electrons line up in the same way that the photons lined up in the first place. The energy carried by these electrons causes the phosphor to reach an excited state and release photons. These phosphors create a green image on the screen, which is a feature of night vision goggles. Through another pair of lenses called eyepieces, the green phosphorescent image can be observed, and can be used to magnify the image or adjust the focus. NVD can be connected to electronic display devices, such as monitors, or directly observe images through eyepieces.
