Which property of tungsten makes it suitable for high-current applications in x-ray tubes?

Tungsten is suitable for high-current applications in x-ray tubes primarily due to its high melting point. In x-ray tubes, the filament is heated to produce electrons through thermionic emission. High currents generate significant heat, and if the material used for the filament does not have a high melting point, it may fail or deform under the intense thermal stress. Tungsten’s melting point is approximately 3,422 degrees Celsius, which allows it to withstand the extreme temperatures generated during x-ray production without losing structural integrity. This property enables tungsten to effectively emit electrons while maintaining its form, making it ideal for the demanding conditions within an x-ray tube.

Other factors, such as thermal conductivity and atomic number, also play roles in material selection but are not as critical as the ability to withstand high temperatures without melting. Low density would not be favorable for durability under high-current conditions; thus, having a high melting point is the definitive property that makes tungsten the preferred choice for x-ray tube applications.