Xenon Compact Arc Lamps*

High brightness compact light sources with spectral energy distribution resembling sunshine are of considerable interest to those who wish to simulate “white” light for illumination or projection. Alternating current xenon compact arc lamps with xenon gas pressures between 20 and 60 atmospheres have been made and their behavior has been compared with similarly constructed mercury filled lamps. Unlike the mercury lamp, which is electrode-stabilized and may be operated in any position, the xenon lamp is convection-controlled and operable only in a nearly vertical position. The lumen efficiency per watt per centimeter of arc is about the same for mercury and xenon; but, because of higher voltage gradients in the former, the over-all efficiency of light production is higher for mercury than for xenon. Radiation characteristics for the xenon lamps were measured. The compactness of the radiating area, about 4.5 mm2 for a 150-watt lamp, and 12 mm2 for a 700-watt lamp, gives the lamp high brightness and makes it an optically useful device.