X-rays coming directly from the target anode are referred to as what?

X-rays that are emitted directly from the target anode of an x-ray tube are known as primary x-rays. These x-rays are generated when high-energy electrons collide with the tungsten target in the anode, resulting in the release of energy in the form of x-rays. Primary x-rays are the most useful for diagnostic imaging, as they are directed toward the patient and are responsible for producing the radiographic images that are essential in dental and medical evaluations.

In contrast, secondary x-rays are those produced when primary x-rays interact with matter, such as the tissues in a patient or other materials, and then are emitted as a result of those interactions. Coherent x-rays are a type of scatter radiation that occurs at low energies where the incoming x-ray photon interacts with matter without significant energy loss but changes direction. Scatter x-rays result from the scattering of primary x-rays after they interact with the patient or other materials.

Thus, identifying primary x-rays helps clarify the origin of the radiation used in imaging, distinguishing them from other types of x-rays that may arise during the process.