ASNT Industrial Radiography Radiation Safety Practice Test

What is the main function of the cathode in X-ray production?

1. To heat the anode

2. To emit electrons

3. To absorb X-rays

4. To regulate radiation exposure

The correct answer is: To emit electrons

The cathode plays a crucial role in X-ray production by emitting electrons. When the cathode is heated, typically through a filament in the X-ray tube, it generates a cloud of electrons around it through a process known as thermionic emission. These emitted electrons are then accelerated towards the anode, where they are directed to collide with the anode material, leading to the production of X-rays. Understanding this function highlights the importance of the cathode in the overall mechanism of X-ray generation, emphasizing its role as the source of the electrons that ultimately produce the X-ray photons upon interaction with the anode.