What percentage of the x-ray beam is characteristic radiation when created above 70 kVp?

Characteristic radiation is produced when an inner-shell electron of a target atom is ejected by an incoming high-energy photon, and subsequently, an electron from a higher energy shell falls into the lower energy shell to fill the vacancy. This process releases energy in the form of x-ray photons.

At higher kilovolt peak (kVp) settings, such as those above 70 kVp, the proportion of characteristic radiation relative to the total x-ray beam increases. The production of characteristic radiation typically becomes more significant as the energy of the photons increases.

In general, when operating at these higher kVp levels, approximately 15% of the x-ray beam consists of characteristic radiation. This percentage reflects the efficiency of electron interactions at elevated energy levels, aligning with the physics of x-ray production in medical imaging contexts. Understanding this percentage is crucial for practitioners, as it impacts factors like beam quality and patient dose optimization in x-ray imaging. Therefore, the choice that states 15% is accurate when considering the typical production mechanics at kVp settings above 70.