Abstract: A high pressure mercury lamp comprises a quartz envelope that contains an atmosphere and a pair of arc-discharge electrodes. These are coil-wound tungsten that has been doped to grain-stabilize the tungsten crystalline structure, e.g., with potassium or potassium and alumina. Preferred potassium doping levels of the tungsten material are in the range of 35-75 ppm. A suitable commercial product of alumina and potassium doped tungsten material is Type BSD-Sylvania. The atmosphere generally comprises a rare gas like xenon, to which is added no more than 0.2 mg/mm3 of mercury so as to keep operating pressure under 200 bar (197 atm). But the electrical power applied is sufficient to maintain arc power loadings of at least 150 watts/mm. The resultant wall loading is more than 0.8 watts/mm2, and lamp operating-power levels can be greater than 150 watts.

Abstract: A high pressure mercury lamp comprises a quartz envelope that contains an atmosphere and a pair of arc-discharge electrodes. These are coil-wound tungsten that has been doped to grain-stabilize the tungsten crystalline structure, e.g., with potassium or potassium and alumina. Preferred potassium doping levels of the tungsten material are in the range of 35-75 ppm. A suitable commercial product of alumina and potassium doped tungsten material is Type BSD-Sylvania. The atmosphere generally comprises a rare gas like xenon, to which is added no more than 0.2 mg/mm3 of mercury so as to keep operating pressure under 200 bar (197 atm). But the electrical power applied is sufficient to maintain arc power loadings of at least 150 watts/mm. The resultant wall loading is more than 0.8 watts/mm2, and lamp operating-power levels can be greater than 150 watts.

Abstract: A primary color lamp comprises a glass envelope with a krypton arc doped with metal halides. A cesium bromide or cesium iodide solution is included with lithium iodide (LiI) to produce red light, thallium iodide (TlI) to produce green light and indium iodide (InI) to produce blue light. The solution controls the vapor pressures of the lithium iodide (LiI), thallium iodide (TlI) and indium iodide (InI) and allows them to be balanced for light amplitude output. No mercury is used in order to eliminate a corresponding yellow light output and the filter complications that result in a system that operates on the primary colors.

Abstract: A metal halide lamp includes a cast ceramic reflector almost completely comprised of alumina. A conventional metal halide bulb is positioned within the reflector. A glaze and then a dielectric coating are applied to the inside surface of the reflector, such that appreciable amounts of infrared radiation from the bulb are absorbed into the glaze and ceramic and not reflected into the beam.

Abstract: A high pressure metal halide lamp comprises an outer envelope and an inner fused silica arc tube whose fill includes sodium iodide. Notwithstanding the use of a divided mount side-rod-less construction, the arc tube is subject to loss of sodium by electrolysis through the walls. The sodium loss is reduced by means of a collector wire within the outer envelope having a control potential thereon which shadows the current carrying lead wire in order to collect electrons that otherwise drift to the arc tube and promote electrolysis.