Abstract: Low-pressure mercury vapor discharge lamp provided with a discharge vessel (10). The discharge vessel (10) encloses a discharge space (11), provided with a filling of mercury and a rare gas, in a gastight manner. At least a part of an inner surface of the discharge vessel (10) is provided with a transparent layer (16) comprising an oxide of scandium, yttrium, or a rare earth metal (lanthanum, cerium, gadolinium, ytterbium, and/or lutetium). The discharge lamp is characterized in that the transparent layer (16) comprises a borate or a phosphate of an alkaline earth metal and/or of scandium, yttrium or a further rare earth metal. Preferably, the alkaline earth metal is calcium, strontium and/or barium. The further rare earth metal is preferably lanthanum, cerium and/or gadolinium. The oxide is preferably Y2O3 or Gd2O3. Preferably, the transparent layer (16) has a thickness of between 5 nm and 200 nm. A luminescent layer (17) is preferably provided on top of the transparent layer in the discharge vessel.

Abstract: 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).