Abstract: An ultraviolet light source includes a volume filled with a dose of AlCl.sub.3 and an inert gas. No mercury is used. During electrical discharge excited states of AlCl.sub.3, AlCl.sub.2, and AlCl emit light, with AlCl having a broad ultraviolet emission peaking at about 261.4 nm. The source may be energized with or without internal electrode. Phosphors may be employed to convert the ultraviolet to visible light. The lamp's envelope may be aluminosilicate coated quartz.

Abstract: To improve the color rendition index R.sub.a, and to lower the color tempture without decreasing the light yield and efficiency of the lamp, the discharge vessel (1, 12, 22) is surrounded by an envelope which comprises a first, or inner envelope element (4, 13, 21) and a second, or outer envelope element (5, 14, 20). The space between the first and second envelope elements, preferably, is evacuated, and the space between the first, inner envelope element and the discharge vessel may include an inert gas, such as nitrogen and/or a noble gas; if the inner envelope element and the discharge vessel are both made of sodium resistant materials, such as Al.sub.2 O.sub.3, the space between the inner envelope element and the discharge vessel may also include sodium of such quantity as to balance the vapor pressure within the discharge vessel and said space outside of the discharge vessel. The lamp can be made double-ended (FIGS. 1, 2) or single-ended (FIG. 3).

Abstract: A compact fluorescent lamp has an outer envelope in which there is supported a capsule containing a mercury-free fill comprised of aluminum trichloride. The fill is energized to produce a plasma discharge which emits ultraviolet and visible radiation. Phosphor, in the form of a particulate layer or a gas, converts the ultraviolet into visible light. The lamp may contain electrodes or be electrodeless. In the electrodeless embodiment RF energy may be capacitively or inductively coupled to the fill.

Abstract: A source of ultraviolet radiation including an electrodeless lamp containing a metal iodide or iodine. When the contents of the electrodeless lamp are excited by high frequency power, excited iodine atoms emit ultraviolet radiation.

Abstract: An electrodeless fluorescent light source including an electrodeless lamp containing a metal iodide or iodine. A fluorescing material is disposed between the electrodeless lamp and an outer envelope. When the contents of the electrodeless lamp are excited by high frequency power, excited iodine atoms emit ultraviolet radiation. The ultraviolet radiation impinges on the fluorescing material causing it to emit visible light. The fluorescing material may be a solid phosphor material on the outer surface of the electrodeless lamp, a solid phosphor material on the inner surface of the outer envelope, a gaseous phosphor material in the space between the electrodeless lamp and the outer envelope, or some combination thereof.

Abstract: The invention relates to a high-pressure discharge lamp for use in the vertical position, having a tubular ceramic discharge vessel, the electrodes being connected to current lead-through members which have been provided one at each end of the discharge vessel, a first, upper current lead-through member consisting of material which is resistant to attack by halogens and/or halides, for example molybdenum, and a second, lower current lead-through member comprising a hydrogen-permeable material, for example niobium.