Optical and Scintillation Properties of Cr Doped Y<sub>3</sub>Ga<sub>5</sub>O<sub>12</sub> Crystal for Infra-Red Scintillators

We evaluated optical and scintillation properties of a Cr 0.5%:Y 3 Ga 5 O 12 (YGG) and Cr 0.5%:Y 3 Al 5 O 12 (YAG) crystals grown by the micro-pulling down method for infrared emission scintillators. In the photoluminescence and X-ray induced radioluminescence measurements, the emissions peaks of Cr:YGG were located in the longer wavelength than those of Cr:YAG. Radioluminescene spectrum of Cr:YGG had a broad peak at 716 nm related to Cr 3+ 2 E→ 4 A 2 and 4 T→ 4 A 2 transitions.