ASNT Industrial Radiography Radiation Safety Practice Test

What does the applied voltage in an X-ray tube mainly affect?

1. Quantity of Electrons

2. Rate of Heat Production

3. Penetration of X-rays

4. Radiation Output

The correct answer is: Penetration of X-rays

The applied voltage in an X-ray tube primarily influences the penetration of X-rays. When the voltage is increased, it enhances the kinetic energy of the electrons that are emitted from the cathode and directed towards the anode. These higher-energy electrons, upon striking the anode, result in the production of X-rays with greater energy. The energy of X-rays is significant because it determines their ability to penetrate various materials. Higher energy (or higher voltage) X-rays can pass through denser materials, which means that as the applied voltage increases, the X-rays produced are more capable of penetrating through layers of tissue or other substances. This principle is crucial for applications in medical imaging and industrial radiography, where the ability to see through different thicknesses or types of materials is essential for accurate analysis. While applied voltage also affects the quantity of radiation produced and the heat created in the anode during operation, the primary impact on the penetration characteristics of the emitted X-rays is a key concept in understanding X-ray tube functionality in various applications.