of the incident radiation. At higher energies ( 60 keV) Compton scattering, the inelastic scattering of photons by bound electrons, often also leading to ionization of the host atom, becomes the more dominant conversion process. The linear attenuation coefficient contribution for Compton scattering is given by: Unlike the photoelectric effect, the absorption resulting from Compton scattering is independent of the atomic number of the atoms present in the crystal, but linearly on their density. At γ-ray energies higher than > 1022 keV, i.e. energies than twice the rest-mass energy of the electron, pair production starts to occur. Pair production is the relativistic phenomenon where the energy of a photon is converted into an electron-positron pair. The created electron and positron will then further interact with the scintillating material to generate energetic electron and holes. The attenuation coefficient contribution for pair production is given by: where is the rest mass of the electron and is the speed of light. Hence, at high γ-ray energies, the energy absorption depends both on the density and average atomic number of the scintillator. In addition, unlike for the photoelectric effect and Compton scattering, pair production becomes more probable as the energy of the incident photons increases, and pair production becomes the most dominant conversion process above ~ 8 MeV. The term includes other (minor) contributions, such as Rayleigh (coherent) scattering at low energies and photonuclear reactions at very high energies, which also contribute to the conversion, however the contribution from Rayleigh scattering is almost negligible and photonuclear reactions become relevant only at very high energies. After the energy of the incident radiation is absorbed and converted into so-called hot electrons and holes in the material, these energetic charge carriers will interact with other particles and quasi-particles in the scintillator (electrons, plasmons, phonons), leading to an "avalanche event", where a great number of secondary electron–hole pairs are produced until the hot electrons and holes have lost sufficient energy. The large number of electrons and holes that result from this process will then undergo thermalization, i.e. dissipation of part of their energy through interaction with phonons in the material The resulting large number of energetic charge carriers will then undergo further energy dissipation called thermalization. This occurs via interaction with phonons for electrons and Auger processes for holes. The average timescale for conversion, including energy absorption and thermalization has been estimated to be in the order of