摘要 |
With high-pressure discharge lamps, and, more specifically, ultra high-pressure discharge lamps, the electrode shafts (4, 5) are located within cylindrical elongated necks (2, 3) of quartz glass extending from the arc tube (1). To prevent adhesion of quartz from the cylindrical elongated necks (2, 3) of the arc tube (1) upon melt-sealing the necks (2, 3) to the electrode shafts (4, 5), the electrode shafts (4, 5) are surrounded by flexible tissue or fabric hoses, tubes or braids (21, 22), made of highly heat-resistant, electrically insulating inorganic material, for example made of quartz fibers. The tissue hose has an inner diameter which corresponds at least to the outer diameter of the eletrode shaft (4, 5) and is not more than 0.5 mm greater than the electrode shaft. Stray molten material from the necks (2, 3) at the junction or transition zone between the arc tube (1) and the respective necks thus cannot adhere to the electrode shafts, and cracking of the quartz glass in the region of the electrode shafts can be avoided.
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