Metal halide lamp having vacuum shroud for improved performance

An automotive headlamp comprising;

• (A) a reflector having a section to which is mated means capable of being connected to an excitation source of an automobile, said reflector having a predetermined focal length and focal point;
• (B) a lens mated to the front section of said reflector;
• and
• (C) an inner envelope predeterminently positioned within said reflector so as to be approximately disposed near said focal length of said reflector,
• (D) a shroud merged with said inner envelope and separated from sidewalls of said inner envelope by a predetermined distance so as to provide a chamber between the inner envelope and said shroud, said chamber being evacuated and containing a hydrogen and water getter;
• said inner envelope containing a fill comprising;
• mercury in an amount in the range of about 2 mg to about 10 mg and a mixture of an amount in the range of about 2 mg to about 50 mg, said mixture selected from the group consisting of sodium iodine, scandium iodine, thallium iodine, indium iodine, tin iodine, dysprosium iodine, holmium iodine, thulium iodine, thorium iodine, cadmium iodine and cesium iodine, said inner envelope having a pair of electrodes separated from each other by a predetermined distance, said inner envelope being connected to said means mated to said section so that said excitation source is capable of being applied across said electrodes, whereby upon such application said mercury and said mixture contained in said inner envelope is excited to as to produce a significant amount of light that is located between said electrodes.