What is the function of the Cathode in an X-Ray tube?

The cathode in an X-ray tube serves as the source of electrons essential for the production of X-rays. It consists of a filament that, when heated, emits electrons through a process called thermionic emission. This field of electrons created by the cathode is critical because, during the operation of the X-ray machine, these electrons are directed towards the anode. Upon striking the anode, the interaction between the high-speed electrons and the metal target results in the generation of X-rays.

While other components such as the anode are responsible for accelerating and targeting the electrons, the cathode's main role is pivotal in initiating the X-ray production process by providing the necessary electrons. Understanding this fundamental role of the cathode helps clarify how X-ray tubes operate as a whole, emphasizing the importance of electron generation in radiography and diagnostic imaging.