Which type of x-rays is classified as characteristic radiation?

Characteristic radiation refers specifically to X-rays that occur when inner-shell electrons are ejected from atoms, typically in the target material of an X-ray tube. When these inner electrons are removed, the atom becomes ionized, creating a vacancy. Electrons from higher energy levels then fall into these lower energy states to fill the vacancies, and this transition emits X-ray photons at distinct energy levels. The energy of these emitted X-rays corresponds to the difference in energy between the two shells involved in the transition, resulting in X-rays that have specific, characteristic energies for the material, which is why they are referred to as "characteristic" radiation.

This process is fundamental to understanding how X-ray machines operate and why certain materials are selected for targets in these devices, as the emitted X-rays can provide specific information about the material being imaged.