High pressure discharge lamp with a thermally improved anode

摘要

A high pressure discharge lamp with a thermally improved anode, as well as a method of making such a lamp, are disclosed. The lamp includes a refractory arc tube with a hermetically sealed arc chamber, a fill in the arc chamber for facilitating light generation, and an anode and a cathode extending into the hermetically sealed arc chamber and being spaced apart from each other. The anode comprises a shank of refractory metal, a cylindrically shaped refractory metal sleeve on a portion of the shank, and an end proximally facing the cathode. The anode end comprises a substantially solid mass of refractory metal, and is integrally joined to both the shank and the metal sleeve to facilitate heat flow from the anode end to the shank and sleeve. The anode end preferably is generally shaped as a hemisphere facing the cathode. The refractory metal sleeve is preferably one or more layers of a helically wound refractory metal wire having an outer diameter more than twice a diameter of the shank.