Basic study of single crystal fibers of Pr:Lu_3Al_5O(12) scintillator for gamma-ray imaging applications

摘要

Single-crystalline fibers were grown from 0.25, 0.70, and 1.50 mol% Pr-doped Lu_3Al_5O(12) (LuAG) melts by the micro-pulling down (u.-PD) method with a diameter of 0.3-0.5 mm and a length of about 200 mm. They were cut to 10 mm long specimens, and their scintillation properties, including light yield and decay time profile, were examined. These results were compared with corresponding properties of the specimens (0.8 × 0.8 × 10 mm~3) cut from the bulk crystals produced by conventional Czochralski (CZ) growth. The u,-PD-grown fibers demonstrated relatively low light yield and had the same decay time constant when compared with those of the samples cut from the CZ-grown crystals. The fiber crystals were used to assemble scintillating arrays with dimensions of 0 0.5 × 10 mm~2 × 20 pixels and 0 0.3 × 10 mm~2× 30 pixels coated by a BaSO_4 reflector. After optical coupling with a position sensitive photomultiplier tube, the fiber-based arrays demonstrated acceptable imaging capability with a spatial resolution of about 0.5 mm.