Patent ID: 7893619

Claim:
A high intensity discharge lamp which operates at over 1000 watts comprising: a discharge vessel; electrodes extending into the discharge vessel, and an ionizable fill sealed within the vessel, the fill comprising: an inert gas, and a halide component comprising: a mercury halide wherein the mercury halide comprises both mercury iodide and mercury bromide, a cesium halide, at least one of a thallium halide and a neodymium halide, and rare earth halides including a dysprosium halide, a holmium halide, and a thulium halide, wherein the fill is free of all rare earth halides other than halides of dysprosium, holmium, neodymium, and thulium, and wherein a molar ratio of halides in the fill is satisfied by: 0.3 ≦X/Y≦ 3.5 where X=Dy+Ho+Z+Tm+Cs, and Dy=moles of dysprosium halide in the fill, Ho=moles of holmium halide in the fill, Z=total moles of thallium halide in the fill, Tm=moles of thulium halide in the fill, Cs=moles of cesium halide in the fill, and Y=moles of mercury halide in the fill.