What is X-ray?
For a more complete understanding of the structure of this system, at first, we describe the X-ray process. X-ray, as shown in Figure 1, is in fact a form of electromagnetic waves in range of gamma ray to UV rays, which is used in crystallography, photography of internal organs of body, photography of through the solid objects, and as one of the non-destructive testing methods
Figure 1. The electromagnetic spectrum
This beam, the first time discovered by Wilhelm Röntgen in 1895, and because of the unknown nature of it, was called X-ray (and sometimes Roentgen beam). He realized that, hitting cathode rays on the vacuum tube walls, producing invisible rays with very high penetration strength, which influence on photographic films. This beams have the ability to pass through the thick layers of opaque materials, including Human body tissues, and as a result, is very dangerous to humans and can cause substantial biological damage. These damage, in humans, are included scald, disease caused by excessive radiation and genetic effects.
X-ray production process
For production of X-ray is used of a metal sample in which electrons are rotating at different levels of energy, like k, L, M and N levels. The metal samples is bombarded by accelerated electrons. In this condition, if the energy of the incident electrons be to extent that it can extract an electron from k level of target atom, as shown in Figure 2 (a), it takes the atom to the excited state, and as a result, leaves a hole of yourself.
In this case, it is possible that, as shown in Figure 2, the evacuated level become to be filled with the transition of an electron from the L level or M level to the K level, and the atom returns to steady state. In this case, their excess energy is emitted as an X-ray photon
Figure 2: X-ray production process
If the transition done, from the level L, the level K, the spectral characteristic Kα, and if the transition done, from the level M to K level, called Kβ radiation.
Thus, we see the following:
Kα = E1 - E0
Kβ = E2 - E0
Figure 3 is also visible the spectral lines like Lβ and Lα, corresponding to the transition between atomic levels.
Kα = E0 – E1
Kβ = E0 - E1
Figure 3: Different types of characteristic spectral lines