The high-voltage between the cathode and the anode affects
the speed at which the electrons travel and strike the anode.
The higher the kilovoltage, the more speed and, therefore,
energy the electrons have when they strike the anode.
Electrons striking with more energy results in X-rays with
more penetrating power. The high-voltage potential is
measured in kilovolts, and this is controlled with the voltage
or kilovoltage control on the control console. An increase in
the kilovoltage will also result in an increase in the intensity of
the radiation. The figure shows the spectrum of the radiated
X-rays associated with the voltage and current settings. The
top figure shows that increasing the kV increases both the
energy of X-rays and also increases the intensity of radiation
(number of photons). Increasing the current, on the other
hand, only increases the intensity without shifting the spectrum.