High-Pressure Discharge Lamp

A high-pressure discharge lamp with a ceramic discharge vessel with a central part and two tubular end regions, which are each closed by sealing parts, electrodes being anchored in the sealing parts, which electrodes extend into the discharge volume enveloped by the discharge vessel, a fill, which contains halogens, in particular metal halides, being accommodated in the discharge volume, characterized in that in each case the following components are contained in the sealing parts:

• a leadthrough, which holds the electrode and which consists of tungsten in the front part and of niobium-like material in the rear part and which is introduced in a ceramic supporting part;
• the front W part is a wire with a diameter DUW of at most 350 μm, preferably at most 250 μm;
• the supporting part has a total length LA over the embedding length of 2 to 8 mm;
• the front W part is accommodated in the supporting part at least over a length LW of 1 mm;
• the aspect ratio LW/DUW, formed from the length of the W part and the diameter of the W part, is at least 10;
• for sealing purposes, in each case glass solder is introduced into the gap between the end region and the supporting part and into the gap between the supporting part and the leadthrough, each glass solder consisting of a mixture of at least two oxides, namely Al2O3 of 30 to 90 mol %, with the remainder being at least one oxide of the rare earths yttrium Y, neodymium Nd, thulium Tm, dysprosium Dy.