Transparent Ceramic Scintillators for Gamma Spectroscopy and Imaging

New transparent ceramic scintillators offer advantages for applications in gamma spectroscopy and X-ray imaging. For gamma spectroscopy, excellent light yield, material uniformity, light yield proportionality, mechanical and environmental ruggedness can be achieved in polycrystalline ceramic oxide garnets. We have fabricated 5 in
³
Ce-doped Gd garnet transparent ceramics. GYGAG(Ce) garnet transparent ceramics offer ρ = 5.8g/cm
³
, Z
_eff
= 48, principal decay of <;100 ns, and light yield of 50,000 Ph/MeV. When pixelated, we obtain R(662 keV) = 3.0%, for GYGAG(Ce) with silicon photodiode readout. For lens-coupled radiographic imaging, thin transparent scintillators without optical scatter are required. The transparent ceramic bixbyite scintillator, (Gd,Lu,Eu)
₂
O
₃
, or “GLO,” offers excellent x-ray stopping, due to its Z
_eff
= 68 and density of 9.1 g/cm
³
. High transparency is achieved by minimizing the formation of secondary phases by adding Gd to the Lu
₂
O
₃
structure. The 12” x 12” GLO imaging plates outperform scintillator glass for MeV radiography, due to higher light yield (55,000 Ph/MeV) and better stopping, while providing spatial resolution of >8 lp/mm for MeV X-rays.