GAGG(Ce) (cerium-doped gadolinium aluminum gallium garnet) is a new type of scintillator that can be used for single photon emission computerized
tomography, gamma ray and Compton scattering detection. Many properties of GAGG(Ce) are suitable for use in gamma ray spectroscopy and medical imaging, such as high photon yield and emission peak near 520 nm,which is very suitable for detection with silicon photomultiplier tubes.
EPIC Crystal provides three types of GAGG crystals: fast decay(GAGG-F), balanced (GAGG-T) and high light output (GAGG-HL) to meet the application needs of  different customer fields.

 https://www.epic-crystal.com/