METAL HALIDE HIGH PRESSURE DISCHARGE LAMP

文件类型：PDF文档
文件大小：394K
A metal-halide high-pressure discharge lamp (1) with a discharge vessel ( 2) and two electrodes (4, 5) has inside discharge vessel (2) an ionizable filling, which contains yttrium (Y) in addition to inert gas, mercury, halogen, thallium (T1), hafnium (Hf), whereby hafnium can be replaced wholly or partially by zirconium (Zr), dysprosium (Dy) and/or gadolinium (Gd) as well as, optionally, cesium (Cs). Preferably, the previously conventional quantity of the rare-earth metal is partially replaced by a molar equivalent quantity of yttrium. With this filling system , a relatively small tendency toward devitrification is obtained even with high specific arc powers of more than 120 W per mm of arc length or with high wall loads. Thus, the filling quantity of cesium can be clearly reduced relative to a comparab le filling without yttrium, whereby an increase in the light flux and particularly in t he brightness can be achieved.