Scintillation Characteristics of the Single-Crystalline Film and Composite Film-Crystal Scintillators Based on the Ce³⁺-Doped (Lu,Gd)₃(Ga,Al)₅O₁₂ Mixed Garnets under Alpha and Beta Particles, and Gamma Ray Excitations

The crystals of (Lu,Gd)₃(Ga,Al)₅O₁₂ multicomponent garnets with high density ρ and effective atomic number Z_eff are characterized by high scintillation efficiency and a light yield value up to 50,000 ph/MeV. During recent years, single-crystalline films and composite film/crystal scintillators were developed on the basis of these multicomponent garnets. These film/crystal composites are potentially applicable for particle identification by pulse shape discrimination due to the fact that α-particles excite only the film response, γ-radiation excites only the substrate response, and β-particles excite both to some extent. Here, we present new results regarding scintillating properties of selected (Lu,Gd)₃(Ga,Al)₅O₁₂:Ce single-crystalline films under excitation by alpha and beta particles and gamma ray photons. We conclude that some of studied compositions are indeed suitable for testing in the proposed application, most notably Lu_1.5Gd_1.5Al₃Ga₂O₁₂:Ce film on the GAGG:Ce substrate, exhibiting an α-particle-excited light yield of 1790-2720 ph/MeV and significantly different decay curves excited by α- and γ-radiation.