The AAPM/RSNA physics tutorial for residents. X-ray production.
X-rays are produced when highly energetic electrons interact with matter and convert their kinetic energy into electromagnetic radiation. The two unique mechanisms by which x-rays are produced are called the bremsstrahlung and characteristic processes. Bremsstrahlung x-rays produce a continuous x-ray spectrum, whereas characteristic x-rays are produced at specific narrow bands of energies. Many technical parameters of the x-ray production equipment affect the magnitude and shape of the x-ray spectrum. The quantity of x-rays produced varies proportionally to the tube potential squared, tube current, exposure time, and atomic number of the anode material and is inversely proportional to the distance squared. x-ray quantity is also affected by the voltage waveform (generator type) and tube filtration. The shape of the x-ray spectrum is affected by the atomic number of the anode material, tube potential, filtration, and voltage waveform.