What material is commonly used for the enclosure of the x-ray tube?

The use of Pyrex glass for the enclosure of an x-ray tube is well-founded due to its unique properties that are essential for the effective functioning of the x-ray equipment. Pyrex glass is designed to withstand the high temperatures generated during x-ray production, as it has a high thermal resistance. This material is also highly transparent to x-rays, allowing the radiation to pass through with minimal attenuation, which is crucial for the efficiency of the x-ray tube. Furthermore, Pyrex glass is strong enough to contain the vacuum within the tube while also being resistant to the corrosive effects of the gases and materials used inside the x-ray tube.

Though other materials like aluminum or stainless steel have their applications in radiation shielding or structural components, they do not possess the necessary properties to act as the main envelope of the x-ray tube. Hence, the choice of Pyrex glass reflects the specific requirements of durability, thermal resistance, and x-ray transparency necessary for the function of x-ray tubes.