Xenon arc lamp
Xenon arc lamps are a source of artificial light. Powered by electricity, they use ionized xenon gas to produce a bright white light that closely mimics natural daylight.
Xenon arc lamps can be roughly divided into three categories:
- Continuous-output xenon short-arc lamps
- Continuous-output xenon long-arc lamps
- Xenon flash lamps (which are usually considered separately)
Each consists of a glass or fused quartz arc tube with tungsten metal electrodes at each end. The glass tube is first evacuated and then re-filled with xenon gas. For xenon flashtubes, a third "trigger" electrode usually surrounds the exterior of the arc tube.
Xenon short-arc lamps
These lamps were invented in the 1940's in Germany and introduced in 1951 by Osram. First launched in the 2kW size (XBO2001), these lamps saw a wide acceptance in movie projection where it advantageously replaced the older carbon arcs. The white continuous light generated with this arc is of daylight quality, but plagued by a rather low lumen efficiency. Today, all movie projectors in theaters employ these lamps with a rating ranging from 900 watts up to 12 kW. When used in Omnimax projection systems, the power can be as high as 75 kW in a single lamp.
The very small optical size of the arc makes it possible to focus the light from the lamp very precisely. For this reason, xenon arc lamps of smaller sizes, down to 10 Watts, are used in optics and in precision illumination for microscopes and other instruments. Larger lamps are also employed in searchlights where narrow beams of light are to be generated.
The use of the xenon technology has spread into the consumer market with the introduction in 1991 of xenon headlamps for cars. In this lamp the glass capsule is small and the arc spans only a few millimetres (hence the name). Additions of mercury and salts of sodium and scandium improve significantly the lumen output of the lamp, the xenon gas being used only to provide instant light upon the ignition of the lamp.
Xenon long-arc-lamps
These are structuraly similar to short-arc lamps except that the arc-containing portion of the glass tube is greatly elongated. When mounted within an elliptical reflector, these lamps are frequently used to simulate sunlight. Typical uses include solar cell testing, solar simulation for age testing of materials, rapid thermal processing, and material inspection.
| Sources of light / lighting
|
| Natural/Prehistoric light sources: |
| bioluminescence (Fireflies, Foxfire, et cetera) | Celestial objects | Lightning |
| Combustion-based light sources: |
| Acetylene/Carbide lamps | Candle | Davy lamps | Fire | Gas lighting | Kerosene lamp | Limelight | Oil lamp | Rushlight |
| Nuclear/direct chemical light sources: |
| Betalights | Chemoluminescence/Lightsticks |
| Electric light sources: |
| Arc lamp | Incandescent | Fluorescent |
| High-intensity discharge: |
| HMI lamps | Mercury-vapor lamps | Metal halide lamps | Sodium vapor lamps | Xenon arc lamps |
| Other electric: |
| Electroluminescent (EL) lamps | Inductive lighting | LEDs | Neon and argon lamps | Sulfur lamp | Xenon flash lamps | Yablochkov candle |