A ballast and metal halide lamp circuit improvement designed to reduce lamp
lumen depreciation over the life of the lamp, wherein the circuit
comprises a high frequency electronic ballast configured to generate high
voltage starting pulses, and a metal halide lamp further comprising an arc
tube containing an ionizable medium, and having main electrodes sealed
into opposed ends of the arc tube, the ionizable medium including mercury,
a metal halide, and an inert gas selected from the group consisting of
argon, krypton, and xenon and mixtures thereof, wherein the starting
pulses are suitable for starting high fill pressure metal halide lamps,
and said inert gas is at a cold pressure of greater than 50 torr.