Beam quality refers to the overall energy or wavelength of the beam and its penetrating power. A high-quality beam has a short wavelength, high mean energy, and increased maximum energy. The kilovoltage controls the beam quality. The kVp regulates the speed of electrons traveling from the cathode to the anode and determines the penetrating ability of the x-ray beam. When the kVp increases, the resulting x-ray beam is of higher energy and increased penetrating ability (Figure 5).1,3,4,7,9
Figure 5. Change of x-ray spectrum with change of kVp.