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After this reading this section you will be able to do the following:

  • Identify the three things needed to generate X-rays.
  • Explain what role electrons play in the creation of X-rays.

So far our discussion has been primarily centered around radioactive elements, the structure of the atom, and the phenomenon of radioactivity. As mentioned earlier, another type of radiation commonly utilized is X-radiation. Where as gamma radiation is one of the products of nuclear decay of radioactive elements, X-rays are produced in high voltage electron tubes. You will recall from the history section that W.C. Roentgen discovered X-rays in the late 1800's while working with a cathode tube in his lab. X-rays can be produced in parcels of energy called photons, just like light.

How do you generate an X-ray?

To generate X-rays, we must have three things. We need to have a source of electrons, a means of accelerating the electrons at high speeds, and a target material to receive the impact of the electrons and interact with them.

Why do we need electrons to produce x-rays?

X-rays are generated when free electrons give up some of their energy when they interact with the orbital electrons or nucleus of an atom. The energy given up by the electron during this interaction appears as electromagnetic energy known as X-radiation. There are two different atomic processes that can produce x-ray photons. One is called Bremsstrahlung and the other is called K-shell emission. X-rays produced by Bremsstrahlung are the most useful for medical and industrial applications.

  • Take this link to learn about a phenomenon in the generation of x-rays called Bremsstrahlung:



  1. The three things needed to create x-rays are a source of electrons, a means of accelerating the electrons to high speeds, and a target for the accelerated electron to interact with.
  2. X-rays are produced when the free electrons cause energy to be released as they interact with the atomic particles in the target.