Abstract
The performance of the compound bromotrifluoromethane (CBrF3) as a tungsten–halogen bulb fill gas was evaluated theoretically by chemical equilibrium calculations. It was found to be an ideal fill gas in terms of maintaining clear bulb walls and redepositing evaporated tungsten on hot spots in the filament. The calculations were done at different CBrF3 and water concentrations. The compounds most responsible for tungsten transport were identified; fluorine compounds of tungsten dominate over bromine compounds. Finally, CBrF3 is compared to other possible fill gases such as CBr2F2, CBr3F, CBr4, and also HBr, since HBr is presently used commercially.