Abstract: A high pressure gas discharge lamp includes first and second discharge devices electrically connected in series within an outer envelope. The discharge devices each include a discharge vessel enclosing a discharge space with an ionizable fill and first and second discharge electrode assemblies. The first discharge electrode assemblies of the discharge devices are connected so as to receive a starting pulse and lamp operating voltage. Each discharge vessel includes a first wall portion spaced from the first discharge electrode assembly and defining an ionizable gap therebetween. A conductive element bridges the discharge devices at the first wall portions and capacitively couples the first discharge electrode assemblies to induce ionization in one of the discharge devices in the ionizable gap between the first wall portion and first discharge electrode assembly.

Abstract: An HID lamp having parts of its internal metal support covered with a layer of material having a photoelectric work function greater than 5.0 electron volts to reduce internal photoelectron production. The material may be granular zirconium oxide having a photoelectric work function of 5.8 eV.