The spectrum is continuous in the visible range and extends far into the ultraviolet. Xenon compact arc lamps are made with rated wattages from 75 to 30,000 watts and are available for operation in either a vertical or horizontal position. The breakdown voltage between the electrodes will run from 10kv for a small lamp up to 60kv or more for lamps rated 30kw. The luminous efficacy of Xenon compact arc lamps is approx. A Mercury-Xenon lamp contains a specific amount of mercury and a small amount of xenon added at a pressure exceeding one atmosphere.
Mercury lamps are sensitive to cooling because the bulb temperature determines the vapor pressure.
The lamp can be over-cooled to the point that full output in the mercury spectrum is never achieved. The cooling water should be ordinary tap water. Chilled water may decrease the operating voltage and interfere with the proper evaporation of mercury. In some cases, the mercury may not evaporate at all, causing unsuitable performance and shortened lamp life. Typical steady state voltage of a Mercury-Xenon lamp is higher than that of a xenon lamp.