New arc ingredients for HID lamps. Final report. [High Intensity Discharge]

The purpose was to examine new gas fills for high intensity discharges (HID) that might give higher efficacy and better color than the conventional metal halide or high-pressure sodium lamp fills currently used in lamps with electrodes. Electrodeless high intensity discharges were established in gases, such as the vaporized chlorides, which would be damaging to electrodes in conventional lamps. Frequency of excitation was 13.56 MHz, and discharge power ranged from about 400 to 1200 W. Electrical and optical properties of the arc were measured. Twenty-one lamps were built and tested. The highest efficacy measured was about 170 lm/W with a fill of mercury, thallium bromide, cerium chloride, and sodium bromide. CRI was about 50 and color temperature 4700K. Molecular radiators alone, such as mercury chloride, gave generally poor efficacy, approx. 80 lm/W. Atomic radiators, from dissociated salts, contributed strongly to the high efficacies. A preliminary examination of possible semiconductor ballast configurations predicts a parts cost of about fifty dollars and an efficacy of about 85%. Stray electromagnetic fields from the lamp assembly are calculated to be below ANSI Standard C95.1-1982 at distances from the lamp of 0.6 m or more. Calculations also show that the lamp cannot meet FCC specifications more » for operation outside ISM bands. A preliminary cost of light analysis compared the electrodeless lamp, a 1000 W HPS lamp, and a 1000 W metal halide lamp for a parking lot application. The electrodeless and HPS lamps were about equivalent with metal halide more costly. « less