Energy Transfer, Fluorescence and Scintillation Processes in Cerium-Doped RE$\text{}^{3+}$ AlO$\text{}_{3}$ Fast Scintillators

Modern applications of scintillators in medical imaging of human body (Positron Emission Tomography - PET scanning, γ-cameras and other X-ray tomographies) require improved or even quite new scintillators which should be characterized by (i) fast response, (ii) high density and (iii) high light yield. At present time new scintillating crystals are investigated, mainly those having perovskite lattice structure of the formula RE$\text{}^{3+}$ AlO$\text{}_{3}$:Ce where RE $\text{}^{3+}$ = Y$\text{}^{3+}$, Gd$\text{}^{3+}$ and Lu$\text{}^{3+}$. Here, we will present the newest data with summarising properties of these types of scintillators including the mixed ones. Energy transfer processes between Ce$\text{}^{3+}$ main centres and Ce$\text{}^{3+}$ multisites are discussed together with their mechanisms including processes between Ce $\text{}^{3+}$ and Gd$\text{}^{3+}$ ions. Finally, the characteristic properties of scintillating crystals based on perovskite structure are reviewed.