ASNT Industrial Radiography Radiation Safety Practice Test

Which process primarily produces X-rays in an X-ray tube?

1. Photoelectric Effect

2. Compton Scattering

3. Bremsstrahlung

4. Thermal Emission

The correct answer is: Bremsstrahlung

The production of X-rays in an X-ray tube primarily occurs through the Bremsstrahlung process. Bremsstrahlung, which is German for "braking radiation," refers to the radiation emitted when high-speed electrons are decelerated upon interacting with the nuclei of the target material (often tungsten) in the X-ray tube. As electrons from the cathode are heated and accelerated towards the anode target, they collide with the metal atoms. During these collisions, the electrons lose energy as they are deflected by the positive charges of the atomic nuclei. This energy loss is emitted in the form of X-ray photons. The efficiency of this process contributes significantly to the overall X-ray production in medical and industrial radiography settings. In comparison, the other options relate to different interactions involving X-rays rather than their production. The photoelectric effect and Compton scattering describe how X-rays interact with matter after they have been produced. Thermal emission, on the other hand, relates to the generation of electrons through heating which can lead to the production of X-rays as a secondary process; however, it is not the primary mechanism for producing X-rays in the tube itself.