ASNT Industrial Radiography Radiation Safety Practice Test

Which component of an X-ray tube is responsible for producing electrons?

1. Target

2. Control Panel

3. Filament

4. Focusing Cup

The correct answer is: Filament

The component of an X-ray tube responsible for producing electrons is the filament. In an X-ray tube, the filament is a thin wire made of a material with a high melting point, typically tungsten. When an electric current passes through the filament, it heats up due to the resistance and begins to emit electrons through a process called thermionic emission. These emitted electrons then move towards the anode (target) and, when directed toward it, interact with the target material to produce X-rays. Understanding the role of the filament is crucial in the context of X-ray production because the number of electrons available for interaction directly affects the density and quality of the resulting X-ray image. The greater the number of electrons produced by the filament, the more X-rays can be generated, leading to better imaging capabilities in industrial radiography.