what gas is in a halogen bulb?
The halogen lamp is also known as a quartz halogen and tungsten halogen lamp. It is an advanced form of incandescent lamp. The filament is composed of ductile tungsten and located in a gas filled bulb just like a standard tungsten bulb, however the gas in a halogen bulb is at a higher pressure (7-8 ATM). The glass bulb is made of fused quartz, high-silica glass or aluminosilicate.