Those quite literally put into typical xenon lamps inside testing and simulation just for the aspect that it's really light exposure for metals and others alike.

Key Features:

• Principle of Operation: Contains xenon that, when electrically energized, emits intense white light covering UV, visible, and infrared wavelengths. Usually used in a controlled environment to apply tests for sun exposure lasting a number of hours.
• Properties Measured: Color fading, surface degradation, oxidation, and material durability under very intense lighting conditions. Helps in assessing the resistance of a certain material under UV exposure and thermal effects.
• Different applications: It's used in weathering tests, material durability and photochemical research. It is important in the automotive industry, aerospace, coatings, plastics, and textiles concerning quality and product development.

A xenon lamp is important in the sense that, how sunlight is created in the real world, it can also be manipulated in a controlled laboratory to produce the same sunlight exposure and then predict on how they would behave in extreme lighting conditions.