Luminescence Properties of ${\rm Gd}_{3}{\rm Ga}_{5}{\rm O}_{12}$:${\rm Cr}$ Single Crystals

We evaluated optical and scintillation properties of a 0.03% Cr-doped Gd
₃
Ga
₅
O
₁₂
(GGG:Cr) single crystal grown by Czochralsk method for medical use. Since human body has low absorption region from approximately 700-1100 nm, near infrared scintillators would be applied to the real time dose monitor system. In the X-ray excited radioluminescence, the emissions related to
²
E →
⁴
A
₂
transitions of Cr
³⁺
were observed at around 725 nm. The scintillation light yield of GGG: Cr 0.03% single crystal under 5.5 MeV alpha-ray excitation was determined to be 30% of BGO.