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Energy changes in an X-ray tube. When the cathode is heated electrons are emitted by thermionic emission. They acquire electrical energy which can be expressed as E = e V. Once in motion the electrical energy is converted to kinetic energy, that is eV = ½ mev2.
The energy of an electromagnetic wave can be calculated using the following equation Energy = h f,where h- Planck’s constant, f – frequency of the wave.
The highest frequency of the X-rays released after an electron hits the target is when the greatest kinetic energy is lost, that is hfmax = eV.
Lower frequencies are released when the electrons make multiple collisions losing energy in stages, the minimum wavelength, ${\lambda}$ min, of the emitted X-rays is given by;
(hc) / ${\lambda}$ min = eV. These expressions can be used to calculate the energy, frequencies and wavelengths of X-rays.
Mutiso answered the question on October 16, 2018 at 19:00
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