What role does glass play in the construction of an x-ray tube?

In the construction of an x-ray tube, glass serves the vital purpose of maintaining a vacuum inside the tube. This vacuum is crucial because it allows for the free flow of electrons from the cathode to the anode without any interference from air molecules. In the presence of air, electrons would collide with gas molecules, which would scatter them and decrease the efficiency of x-ray production. Therefore, the glass envelope is designed to be airtight, creating a vacuum that enhances the performance of the x-ray tube by enabling the electrons to travel unimpeded, thereby generating x-rays effectively when they strike the target material, typically tungsten. This structural integrity and functionality of glass in creating a vacuum is fundamental to the operation of x-ray tubes.