What is the maximum energy of the photons in the x-ray spectrum limited by?

The maximum energy of the photons in the x-ray spectrum is determined by the energy of the electrons that are incident on the target. When high-energy electrons collide with the target material in an x-ray tube, they can transfer their energy to the target atoms, resulting in the production of x-rays. The energy of the produced photons can reach up to the level of the kinetic energy of the electrons before any losses or interactions occur, such as those with the target material or through the emission of lower-energy photons.

In the context of x-ray production, the incident electrons are accelerated to high energies by a high-voltage potential before striking the target. Because the energy of the emitted photons cannot exceed the maximum energy provided by these incident electrons, it acts as a key limiting factor in determining the highest energy level present in the x-ray spectrum. Thus, understanding the relationship between the energy of the incident electrons and the maximum photon energy is essential for both the production and effective use of x-rays in medical imaging and treatment applications.