Glossary

A halogen lamp is an incandescent lamp with a tungsten filament contained within an inert gas and a small amount of a halogen such as iodine or bromine. The combination of the halogen gas and the tungsten filament produces a chemical reaction known as a halogen cycle (see below) that increases the lifetime of the bulb and prevents its darkening by redepositing tungsten from the inside of the bulb back onto the filament.