American Society for Nondestructive Testing (ASNT) Radiographic Testing Practice Test

The photoelectric effect primarily involves X-rays due to their ability to provide sufficient energy to dislodge electrons from atoms. This process occurs when photons, which are packets of light and electromagnetic radiation, collide with matter. X-rays, being high-energy photons, have the necessary energy to overcome the binding energy of electrons in an atom.

When an X-ray photon interacts with a material, it can transfer its energy to an electron, typically in the inner shell of the atom. If the energy transferred is greater than the binding energy of that electron, the electron will be ejected from the atom, creating a photoelectron. This phenomenon is a fundamental principle in radiographic testing, as it heavily influences image formation and material interaction.

Other types of radiation like beta particles, alpha particles, and microwaves do not primarily engage in this effect. Beta and alpha particles are forms of particle radiation rather than electromagnetic radiation, and thus they do not operate on the same principles as X-rays in terms of energy transfer and electron ejection. Microwaves, being lower in energy compared to X-rays, typically do not possess sufficient energy to cause the photoelectric effect, focusing instead on the vibrational and rotational transitions of molecules rather than ionization.