When high-energy X-rays collide with atoms when the energy is higher than the electrons in the inner layer of atoms, the expulsion of an inner electron and the emergence of a hole, so that the entire atomic system in an unstable excited state, the excited atom life of about 10-12-10-14s, and then spontaneously from the state of high energy to transition to low energy state. This process is called the relaxation process. The relaxation process can be either a non radiative transition or a radiation transition. When the outer electrons jump to the hole, the released energy is absorbed within the atom and expelled from the outer layer of another secondary photoelectron, known as the Auger effect, also known as the secondary photoelectric effect or no radiation effects, expelled by the secondary photoelectron known as Auger Electron. Its energy is characteristic and has nothing to do with the energy of the incident radiation. When the energy emitted by the outer electrons into the inner hole is not absorbed in the atom, but emitted in the form of radiation, the X-ray fluorescence is produced, and the energy is equal to the energy difference between the two levels. Thus, the energy or wavelength of the X-ray fluorescence is characteristic and has a one by one correspondence with the element.
When the K-layer electrons are ejected, the holes can be filled by any electron in the outer layers, thus, a series of spectral lines, called K-Lineage lines: X-rays that are transferred from the L-layer to the K-layer radiation, are called kα rays, and X-rays from the M-layer to the K-layer radiation are called kβ rays .... Similarly, the L-layer electrons are ejected to produce L-system radiation (see Figure 10.2). If the incident X-ray causes the K-layer electrons of an element to excite into the e-layer into the K-layer, then there is the energy Δe released, and Δe=ek-el, the energy is released in the form of X-rays, resulting in the Kα ray, also can produce kβ Ray.