The internal surface of the faceplate is coated with the phosphor. The phosphorous converts the electrical energy into light energy. The energy level of the phosphorous crystal raises when the electron beams strike on it.
This phenomenon is called cathodoluminescence. The light which is emitted through phosphorous excitation is called fluorescence. When the electron beam stop, the phosphorous crystal regain their original position and release a quantum of light energy which is called phosphorescence or persistence. The Aquadag is the aqueous solution of graphite which is connected to the secondary of the anode.
The Aquadag collects the secondary emitted electrons which are necessary for keeping the CRT screen in the state of electrical equilibrium. Very informative and comprehensive article. I have been looking for a such detailed explanation. Thank you. The ideal CRT is enclosed by Helmholtz coils to allow a varying magnetic field to be applied. In the absence of Helmholtz coils, a strong neodymium magnet should suffice to bend the electron beam. The beams of electrons are too dim for anything except a very small audience to see directly, and are something of a challenge for video equipment too!
A camera with a night mode, or manual control over gain or ISO and shutter speed will probably be necessary. The key here is that magnetic fields will bend the path of a moving charged particle, and we can make use of this effect to control a beam. Crucially for the Accelerate! The steering coils create a magnetic field, which guides the beam so that it scans back and forth across the screen, starting at the top. Air is withdrawn from the CRT so that air molecules don't interfere with the passage of electrons between the electron gun and the screen.
Phosphor is the name given to any substance that emits visible light when exposed to radiation, such as ultraviolet light, or, in this case, a beam of electrons. The electrons collide with the phosphor atoms, causing them to gain energy or become "excited.
Display History In , IBM introduced the Color Graphics Adapter CGA , which was capable of rendering four colors, and had a maximum resolution of pixels horizontally by pixels vertically. EGA allowed up to 16 different colors and increased the resolution to x pixels, improving the appearance of the display and making it easier to read text. Read More. Cite This! Print Citation. Try Our Sudoku Puzzles!
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