Why do halogen lights shine so bright white compared to other light bulbs???

Question

Thanks for your answer...Tom Science 4

Answer 1

A halogen bulb uses a chemical trick to prolong the life of its filament. In a regular bulb, the filament slowly thins as tungsten atoms evaporate from the white-hot surface. These lost atoms are carried upward by the inert gases inside the bulb and gradually darken the bulb's upper surface. In a halogen bulb, the gases surrounding the filament are chemically active and don't just deposit the lost atoms at the top of the bulb. Instead, they react with those tungsten atoms to form volatile compounds. These compounds float around inside the bulb until they collide with the filament again. The extreme heat of the filament then breaks the compounds apart and the tungsten atoms stick to the filament.This tungsten recycling process dramatically slows the filament's decay. Although the filament gradually develops thin spots that eventually cause it to fail, the filament can operate at a higher temperature and still last two or three times as long as the filament of a regular bulb. The hotter filament of a halogen bulb emits relatively more blue light and relatively less infrared light than a regular bulb, giving it a whiter appearance and making it more energy efficient and typically brighter.

So basically, the chemical reaction in the bulb is what really matters.

Answer 2

Quoted from Wikipedia:

"One invention that addressed the problem of short lamp life was the halogen lamp, also called the tungsten-halogen lamp, the quartz-halogen lamp or the quartz-iodine lamp, wherein a tungsten filament is sealed into a small envelope filled with a halogen gas such as iodine or bromine. In an ordinary incandescent lamp, the thickness of the filament may vary slightly. The resistance of the filament is higher at the thinner portions which causes the thin areas to be hotter than the thicker parts of the filament. The rate of tungsten evaporation will be higher at these points due to the increased temperature, causing the thin areas to become even thinner, creating a runaway effect until the filament fails. A tungsten-halogen lamp creates an equilibrium reaction in which the tungsten that evaporates when giving off light is preferentially re-deposited at the hot-spots, preventing the early failure of the lamp. This also allows halogen lamps to be run at higher temperatures which would cause unacceptably short lamp lifetimes in ordinary incandescent lamps, allowing for higher luminous efficacy, apparent brightness, and whiter color temperature. Because the lamp must be very hot to create this reaction, the halogen lamp's envelope must be made of hard glass or fused quartz, instead of ordinary soft glass which would soften and flow too much at these temperatures."