Xenon Gas-Discharge Lamp

a gas-discharge light source in which electric power is converted into light by an arc discharge in a xenon atmosphere. The characteristic features of xenon lamps are a continuous radiation spectrum, close to that of the sun; a rising current-voltage characteristic, which simplifies the conditions for power supply and regulation; a large brightness and power range; and the possibility of using either natural or forced (water) cooling.

A xenon lamp is a quartz bulb filled with xenon, having built-in sealed electrodes, between which the electric arc forms. A distinction is made between tubular high-pressure lamps, in which the arc is stabilized by the walls of the tube, and super-high-pressure spherical lamps, in which the arc burns freely between the electrodes. The power of the tubular lamps reaches 100 kilowatts (kW), the luminous efficiency is 20–40 lumens per watt, the gas pressure is about 0.1 meganewtons per sq m (MN/m²), or 1 kilogram-force per sq cm (kgf/cm²); and the service life is more than 500 hr. Lamps of this type are used to illuminate open areas (squares in cities; railroad stations) and for cultivating plants. The brightness of spherical lamps is comparable to that of the sun. Their power is 0.1-30.0 kW; their luminous efficiency is about 50 lumens per watt; their gas pressure is 0.5-3.0 MN/m² (5-30 kgf/cm²); and their service life is 100–500 hr. Lamps in a metal shell with a spherical output window, having a power of more than 40 kW, are a variety of spherical lamp. The spherical lamps are extensively used in searchlight technology and motion-picture engineering, for simulating solar radiation, and in optical furnaces. The principal trend in improvements is an increase in the power, service life, and reliability.