Radiologic Technologist Practice Exam

What type of x-ray is produced when kVp is increased to a point where the binding energy of a tungsten atom is not broken?

1. Characteristic x-rays

2. Photoelectric x-rays

3. Bremsstrahlung x-rays

4. X-ray scatter

The correct answer is: Bremsstrahlung x-rays

When kVp (kilovolt peak) is increased, the energy of the x-ray photons produced also increases. Bremsstrahlung x-rays are generated when high-speed electrons are decelerated or 'braked' as they pass near the nucleus of a tungsten atom. This interaction results in the conversion of kinetic energy to x-ray energy without breaking the binding energy of the tungsten atom. Characteristic x-rays are produced when an inner-shell electron is ejected from a tungsten atom, causing an outer-shell electron to fall into the lower energy state, which releases energy in the form of x-rays. This process requires enough energy to overcome the binding energy of the electron being removed, which is not the scenario when simply increasing kVp without sufficient energy to displace electrons. Photoelectric x-rays are associated with the complete absorption of photon energy by an inner-shell electron, facilitating ionization rather than x-ray production. X-ray scatter does not relate to the production of distinct x-ray types but refers to the dispersion of x-rays as they interact with matter, resulting in reduced image quality rather than the generation of new x-ray photons. In summary, increasing kVp leads to the production of Bremsstrahlung x-rays, specifically when the energy is sufficient to create