Low-pressure mercury vapor discharge lamp with a spiral-shaped electrode shield

摘要

The discharge vessel encloses a discharge space provided with a filling of mercury and a rare gas in a gastight manner. Each end portion (12a) of the lamp supports an electrode (20a) arranged in the discharge space. An electrode shield (22a) encompasses at least one of the electrodes (20a) and has a substantially spiral-shaped cross-section. Preferably, the electrode shield (22a) is made from a ceramic material and is covered with a material which reacts with or forms an alloy with alkaline earth metals released by the electrode (20a).