High-pressure metal halide discharge lamp and a lighting apparatus using the lamp

A lighting apparatus, comprising:

• a high-pressure metal halide discharge lamp for use in an upright mounted position, comprising:
• a sealed light-transmitting discharge vessel having first and second seals and enveloping a discharge space that holds a gas comprising a rare gas and metal halides,
• a first electrode comprising a first material and sitting at a lower side in the discharge space,
• a second electrode comprising a second material and sitting at an upper side in the discharge space, wherein the first material emits electrons at a higher rate than the second material, and
• first and second conductive wires each connected to one of the electrodes, located in the first and second seals, and extending from the discharge vessel, and
• an outer bulb having a lamp cap and surrounding said discharge vessel;
• and a luminarie housing having a ballast and a socket connected to said lamp cap, the high-pressure metal halide discharge lamp being constructed and arranged to receive and be powered by an alternating current power.