Scintillation properties of multilayered composite scintillators based on the YAG:Ce and TbAG:Ce single crystalline films and GAGG:Ce crystal substrates

Abstract

This work demonstrates current progress of our group in developing of two- and three-layered composite for radiation monitoring of various components of mixed ionization radiation fluxes based on the epitaxial structures of $Ce^{3+}$ doped garnet compounds using the Liquid Phase Epitaxy growth technique. These scintillators contain one or two single crystalline films, dedicated for registration of low-penetrating particles, and bulk single crystal substrates used for detection of high penetrating $\gamma$-rays. For creation of two- and three-layered epitaxial structures, the single crystalline films of $Ce^{3+}$ doped $Y_3Al_5O_{12}$, $Tb_3Al_5O_{12}$ and $Tb_2GdAl_5O_{12}$ garnets were used. The single crystal of mixed $Gd_3Ga_xAl_{5-x}O_{12}:Ce$ garnet with fixed Ga concentrations of $x = 2.3$ and $3.0$ are utilized as substrates. To assess the scintillation properties of these epitaxial structures, the pulse height spectra, light yield and scintillation decay kinetics were measured under excitation by $\alpha$-particles ($^{239}\text{Pu}$), $\beta$-particles ($^{90}\text{Sr} + ^{90}\text{Y}$) and $\gamma$-rays ($^{137}\text{Cs}$). Finally, the figure-of-merit of composite scintillators under study were calculated for selection of the best epitaxial structures for simultaneous registration $\alpha$- and $\beta$-particles and $\gamma$-rays.