AC HIGH PRESSURE DISCHARGE LAMP, ESPECIALLY FOR HIGH CURRENT LEVEL OPERATION

摘要

To prevent the formation of melt-back slugs or granules on electrodes of high pressure, high power discharge lamps, when the lamps are operated under alternating current conditions of between about 20 to 60 A, for example, the electrodes are terminated in regions of decreasing diameter and, in accordance with the invention, comprise tungsten doped with lanthanum oxide (La203) between about 0.5 to 2%, by weight, preferably about 1%. The doping intensity may increase towards the inside region of the electrode.