Xenon arc lamp

A xenon arc lamp is a specialized type of gas discharge lamp, an electric light that produces light by passing electricity through ionized xenon gas at high pressure. It produces a bright white light that closely mimics natural sunlight. Xenon arc lamps are used in movie projectors in theaters, in searchlights, and for specialized uses in industry and research to simulate sunlight. Xenon headlamps in automobiles actually use metal-halide lamps where a xenon arc is only used during start-up.

Xenon arc lamps can be roughly divided into three categories: continuous-output xenon short-arc lamps, continuous-output xenon long-arc lamps, and xenon flash lamps (which are usually considered separately).

Each consists of a fused quartz or other heat resistant glass arc tube, with a tungsten metal electrode 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. The lifetime of a xenon arc lamp varies according to its design and power consumption, with one major manufacturer quoting average lifetimes ranging from 500 hours (7kW) to 1,500 (1kW).

Xenon short-arc lamps were invented in the 1940s in Germany and introduced in 1951 by Osram. First launched in the 2 kW size (XBO2001), these lamps saw wide use in movie projection, where they replaced the older, more labor intensive (to operate) carbon arc lamps. The white continuous light generated by the xenon arc is spectrally similar to daylight, but the lamp has a rather low efficacy in terms of lumens of visible light output per watt of input power. Today, almost all movie projectors in theaters employ these lamps, with power ratings ranging from 900 watts up to 12 kW. Omnimax (Imax Dome) projection systems use single xenon lamps with ratings as high as 15 kW. As of 2016, laser illumination for digital theater projectors, is starting to establish a market presence  and has been predicted will supersede the xenon arc lamp for this application.

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