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a b s t r a c tInorganic scintillators are very important in medical and industrial measuring systems in the detection and measurement of ionizing radiation. In addition to Ce 3 þ , a widely used dopant ion in oxide scintillators, divalent Europium (Eu 2 þ ) has shown promise as a high-luminescence, fast-response luminescence center useful in the detection of ionizing radiation. In this research, aluminum oxide (Al 2 O 3 ) was studied as a host material for the divalent europium ion. Polycrystalline samples of Eu 2 þ -doped translucent Al 2 O 3 were fabricated, and room temperature luminescence behavior was observed. Al 2 O 3 ceramics doped with 0.1 at% Eu 2 þ were fabricated with a relative density of 99.75% theoretical density and in-line transmittance of 22% at a wavelength of 800 nm. The ceramics were processed by a gel-casting method, followed by sintering under high vacuum. The gelling agent, a copolymer of isobutylene and maleic anhydride, is marketed under the commercial name ISOBAM, and has the advantage of simultaneously acting as both a gelling agent and as a dispersant. The microstructure and composition of the vacuum-sintered Eu 2 þ :Al 2 O 3 were characterized by Scanning Electric Microscopy (SEM), Transmission Electron Microscopy (TEM), and Energy-dispersive X-ray spectroscopy (EDS). The phase composition was determined by X-ray diffraction measurements (XRD) combined with Rietveld analysis. The photoluminescence behavior of the Eu 2 þ :Al 2 O 3 was characterized using UV light as the excitation source, which emitted blue emission at 440 nm. The radio-luminescence of Eu 2 þ :Al 2 O 3 was investigated by illumination with X-ray radiation, showing three emission bands at 376 nm, 575 nm and 698 nm. Multiple level traps at different depths were detected in the Eu 2 þ :Al 2 O 3 by employing thermoluminescence measurements.

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Tl2LiYCl6:Ce (TLYC) is a recently discovered dual mode gamma-ray and neutron scintillator. So far small crystals of this composition have been studied, but for practical applications with affordable price, large-scale crystals are required. In this work, we present successful efforts to grow crack-free single crystals with sizes up to ⌀1″ × 5.5″. A variety of experimental techniques were employed to investigate the scintillation properties. A ⌀1″ × 1.2″ TLYC cylinder has a light yield of 25,000 ph/MeV, and its energy resolution is better than 4% at 662 keV. The gamma equivalent energy (GEE) produced by thermal neutron is 1.89 MeVee, along with a neutron induced light yield of 47,000 ph/n. Pulse shape discrimination (PSD) between gamma-rays and neutrons has been successfully shown with a current Figure-of-Merit (FOM) of 2.4. This article explores the crystal growth, scintillation properties, and potential applications of TLYC.

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