Metal halide lamp having improved lumen maintenance

A metal halide lamp having improved lumen maintenance comprising:

• a discharge vessel;
• at least one electrode extending into the discharge vessel, the electrode comprising a tungsten tip and a molybdenum coil, at least a portion of said molybdenum coil has been oxidized into a porous conducting MoO3 film that releases oxygen into the discharge vessel when the lamp is heated to maintain a wall cleaning tungsten halogen chemical cycle;
• and
• an ionizable fill sealed within the discharge vessel comprising a halogen.

A metal halide lamp having improved lumen maintenance comprising:

• a discharge vessel;
• at least one electrode extending into the discharge vessel;
• and
• an ionizable fill sealed within the discharge vessel comprising a halogen;
• wherein the electrode comprises a tungsten tip of the electrode, at least a portion of said tungsten tip has been oxidized into a dense insulating WO3 film that releases oxygen into the discharge vessel when the lamp is heated in an amount effective to maintain a wall cleaning tungsten halogen chemical cycle.

A metal halide lamp having improved lumen maintenance comprising:

• a discharge vessel;
• at least one electrode extending into the discharge vessel;
• and
• an ionizable fill sealed within the discharge vessel comprising a halogen;
• wherein the electrode comprises a tungsten tip of the electrode, at least a portion of said tungsten tip has been oxidized into a MoO3 and/or WO3 film that releases oxygen into the discharge vessel when the lamp is heated in an amount effective to maintain a wall cleaning tungsten halogen chemical cycle.