Properties of Yb:YAG scintillators

Relative light yield (LY) dependence on temperature for Yb:YAG crystals containing from 10% to 100% of Yb dopant is studied for γ and α excitations. The maximum LY is achieved at 120 K<T<140 K. LY=(13.5±2.5) 103 ph/MeV at T=140 K for (Yb 25%)YAG. Linearity of the light output is checked. α/γ ratio is found to be 0.42±0.02. Pulse shapes induced by gamma and alpha particles and cosmic rays are investigated by analyzing a set of single events recorded. Gamma events are fast τ<4 ns), while other kinds of radiation give rise to more complicated and longer profiles, allowing particle discrimination. Dependence of scintillation properties on concentration of Yb and purity is discussed.