ELEKTRODENLOSE NIEDERDRUCK-ENTLADUNGSLAMPE

摘要

An electrodeless discharge lamp has a cylindrical lamp bulb 1 of, for example, quartz glass, which is surrounded by cylindrical excitation coil 6 and within the lamp bulb 1, there is a cylindrical shutter body 2 of, for example, boron nitride, extending in radial direction up to the inner surface of the bulb 1, which shutter body 2 contains a continuous coaxial aperture 3 for contracting the plasma arising when the lamp is in operation, the shutter body 2 having an optical axis 4 running through its aperture 3, along which the radiation emerges in a directed manner. The shutter body 2 may alternatively be formed of ceramic, eg aluminium oxide, thorium oxide, beryllium oxide or aluminium nitride, molybdenum, diamond or graphite, or as a constriction formed from the quartz glass envelope itself. The lamp bulb may be provided with a reflective coating except at the light-emitting ends, and the aperture at the ends of the shutter body may widen into a truncated cone or a parabolic shape which is provided with a reflective coating, Figs. 3a, 3b, 3c (not shown). The fill gas may comprise hydrogen, denterium or a rare gas. Two such lamps, eg having different light outputs, may be arranged axially, Fig. 6 (not shown), and the combined axial output used, eg, in a spectral photometer. <IMAGE>