Abstract: A discharge lamp having an emission part with a roughly spherical external shape and tube arms extending from opposite sides of the emission part, hermetically sealing parts formed on an end of each robe arm, and a lead pin extending parallel to a longitudinal axis of the tube arm, a tip of each lead carrying an electrode in the emission part, so that a pair of electrodes are arranged opposite one another in the emission part. Within each babe arm, in the vicinity of the emission part, a plate-shaped holding part which is made of a metal with a high melting point and through which the lead pin penetrates, is arranged roughly perpendicularly to the lead pin and serves for positioning of the electrodes.

Abstract: A discharge lamp in which vaporization and melting of a cathode tip are prevented and which has stable luminous operation over a long is achieved according to the invention by the fact that the discharge lamp has a cathode in which a sintered body made of a powdered metal with a high melting point and a powdered emitter material is inserted in the tip, and the relationship:(-0.002d+0.01).ltoreq.D/W.ltoreq.(-0.002d+0.04)is fulfilled, where D is an outside diameter of the sintered body in millimeters (mm), W is a lamp input power in watts (w) and d is a distance between the anode and cathode in millimeters (mm). Furthermore, these benefits are achieved according to the invention by encapsulating mercury in an amount of 10 mg to 80 mg/cc of fluorescent tube internal volume and inert gas with at least 2 atm air pressure (at a reference temperature of 25.degree. C.).