glow discharge
Quick Summary
A glow discharge is a luminous electrical discharge without sparks that occurs through a gas. This phenomenon is a type of plasma, which is an ionized gas.12
Glow discharges are responsible for the light emitted by devices such as neon tubes and fluorescent lamps. In these applications, a gas within a transparent container is energized by an applied voltage, causing it to glow. The glow discharge typically occurs at pressures around one-thousandth of an atmosphere.23
While glow discharges are used in lighting, they also have other applications. They can be used in electronic switching devices and to generate ions for particle accelerators. A related device, the glow switch, is used as a starting switch in fluorescent lamps.24
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