Non-proportionality and Energy Resolution of LuXY1-XAG:Pr and LuAG:Pr,Mo Crystals

Recently, there has been an increased interest in the scintillators belonging to the family of garnet crystals. Praseodymium activated LuAG (Lu
₃
Al
₅
O
₁₂
:Pr) shows decent properties in terms of light output, energy resolution and fast emission originating from 5d
¹
4f
¹
→ 4f
²
transitions in Pr
³⁺
, peaking at 310 nm. Since the material shows potential for application as a detector in PET imaging, there have been attempts to improve the properties of this crystal. Previously published results show that the aim to enhance light yield and energy resolution has been successful and in this communication we report extended and detailed study of the influence of crystal composition on non-proportionality characteristics and energy resolution. A wide array of radiation sources emitting gamma radiation in the range between 14.4 to 1274 keV were used to perform measurements on a series of mixed (Lu
_x
Y
_1-x
)
₃
Al
₅
O
₁₂
crystals, where x = 0.00, 0.25, 0.50, 0.75, 1.00 and on LuAG:Pr co-doped with trace amounts of molybdenum (Mo at 0.005, 0.0009 and 0.0005 % mol.). The measurements were performed at 0.5 and 10 μs shaping times to study the impact of the material composition on longer decay components of the pulse shape and on linearity of the scintillation response.