X-RAY PHOTON. A brief definition of an x-ray photon was previously stated. However, a more comprehensive definition is necessary for the next series of photon actions. X-ray photons are electromagnetic rays produced in the x-ray tube head when electrons from the cathode filament strike the anode target. They are bundles of pure energy. The photons transfer their energy to the substance through which they pass whether it be air, an x-ray film, or the living tissue of the patient or the specialist. They cannot be seen or felt. a. Photon Action Upon Atoms. (1) Photon collision with the nucleus of an atom. The photon may strike the nucleus of an atom.