HIGH-PRESSURE DISCHARGE LAMP WITH MERCURY CHLORIDE HAVING A LIMITED CHLORINE CONTENT

摘要

The invention relates to a high-pressure discharge lamp with a discharge vessel having a filling comprising - a rare gas, for example argon, - mercury, and - chlorine, wherein the filling quantities of mercury [Hg] and chlorine [Cl] comply with the following conditions: - [Hg]OE[Cl] ³ 200 (µmole/cm3)2, - [Cl] £ 10 µmole/cm3. The condition [Hg]OE[Cl] ³ 200 (µmole/cm3)2 achieves HgCl vapor pressures in the discharge sufficient for generating significant radiation components of the B2S+-X2S+ band system of this molecule. The condition [Cl] £ 10 µmole/cm3 serves to limit the chemical aggressiveness of the chlorine filling, in particular to limit the attacks on the wall and electrodes and thus to achieve longer lamp lives. The addition of chlorine-binding metals, in particular of germanium, leads to a further improvement in the radiation and life properties of the lamp.