Fundamental Limitations in the Performance of ${\rm Ce}^{3+}$ –, ${\rm \Pr}^{3+}$ –

The fundamental limits on the scintillation decay, scintillation yield, and X-ray or γ-ray energy resolution obtainable with Ce³⁺, Pr³⁺, and Eu²⁺ activated inorganic scintillators are determined. Those limits are compared with what has been achieved today with scintillators like YAlO₃:Ce, Lu₂SiO₅:Ce, LaCl₃:Ce, LaBr₃:Ce, Lul₃:Ce, and emerging scintillators like Lu₃Al₅O₁₂:Pr³⁺ and SrI₂:Eu²⁺. Higher scintillation yield not necessarily leads to better energy resolution; nonproportional scintillation yield with deposited amount of ionization energy is an important aspect too that will be addressed.