X-ray-Induced scintillation properties of Cr-Doped Mg 4 Ta 2 O 9 single crystals in Near-Infrared regions

0.1 %, 0.5 % and 1 % Cr-doped Mg 4 Ta 2 O 9 single crystals were synthesized by the floating zone method and their photoluminescence (PL) and scintillation properties were assessed. Cr-doped Mg 4 Ta 2 O 9 single crystals showed a broad PL band between 700 and 1100 nm in the near-infrared region, which is attributed to the 4 T 2 – 4 A 2 ( 4 F) transition of Cr 3+. As the scintillation properties, Cr-doped Mg 4 Ta 2 O 9 single crystals show broad emission bands at 300–450 and 750–1100 nm, which were attributed to charge transfer from Ta 5+ to O 2– and the 4 T 2 – 4 A 2 ( 4 F) transition of Cr 3+, respectively. The afterglow levels of the 0.1 %, 0.5 % and 1 % Cr-doped Mg 4 Ta 2 O 9 single crystals were 9.5, 33.8 and 47.0 ppm, respectively. As a characteristic of a scintillation detector, the lower detection limits were 0.001 Gy/h for the 0.1 % sample, 0.003 Gy/h for the 0.5 % sample and 0.006 Gy/h for the 1 % sample based on the dose rate response function.