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Crystal Growth and Scintillation Properties of ${\rm Cs}_{2}{\rm NaGdBr}_{6}{:}{\rm Ce}^{3+}$

IEEE Transactions on Nuclear Science

Doty, F.P.; Zhou, Xiaowang; Deng, Haoran; Rodriguez, Marko A.

Single crystals of Cs2NaGdBr6 with different Ce+3 activator concentrations were grown by a two-zone Bridgman method. This new compound belongs to a large elpasolite halide (A2BLnX6) family. Many of these elpasolite compounds have shown high luminosity, good energy resolution and excellent proportionality in comparison to traditional scintillators such as CsI and NaI; therefore, they are particularly attractive for gamma-ray spectroscopy applications. This study investigated the scintillator properties of Cs2NaGdBr6:Ce+3 crystals as a new material for radiation detection. Special focus has been placed on the effects of activator concentration (0 to 50 mol.%) on the photoluminescence responses. Results of structural refinement, photoluminescence, radioluminescence, lifetime and proportionality measurements for this new compound are reported.

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Application of in-situ ion irradiation TEM and 4D tomography to advanced scintillator materials

Proceedings of SPIE - The International Society for Optical Engineering

Pratt, Sarah H.; Hattar, Khalid M.; Boyle, Timothy; Villone, Janelle; Yang, Pin; Doty, F.P.; Hernandez-Sanchez, Bernadette A.

Scintillating nanomaterials are being investigated as replacements for fragile, difficult to synthesize single crystal radiation detectors, but greater insight into their structural stability when exposed to extreme environments is needed to determine long-term performance. An initial study using high-Z cadmium tungstate (CdWO4) nanorods and an in-situ ion irradiation transmission electron microscope (I3TEM) was performed to determine the feasibility of these extreme environment experiments. The I3TEM presents a unique capability that permits the real time characterization of nanostructures exposed to various types of ion irradiation. In this work, we investigated the structural evolution of CdWO4 nanorods exposed to 50 nA of 3 MeV copper (3+) ions. During the first several minutes of exposure, the nanorods underwent significant structural evolution. This appears to occur in two steps where the nanorods are first segmented into smaller sections followed by the sintering of adjacent particles into larger nanostructures. An additional study combined in-situ ion irradiation with electron tomography to record tilt series after each irradiation dose; which were then processed into 3D reconstructions to show radiation damage to the material over time. Analyses to understand the mechanisms and structure-property relationships involved are ongoing. © 2012 SPIE.

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Elpasolite scintillators

Doty, F.P.; Yang, Pin; Zhou, Xiaowang; Rodriguez, Mark A.

This work was funded by the U.S. Department of Energy Office of Nonproliferation Research to develop elpasolite materials, with an emphasis on high-atomic-number rare-earth elpasolites for gamma-ray spectrometer applications. Low-cost, high-performance gamma-ray spectrometers are needed for detection of nuclear proliferation. Cubic materials, such as some members of the elpasolite family (A2BLnX6; Ln-lanthanide and X-halogen), hold promise due to their high light output, proportionality, and potential for scale-up. Using both computational and experimental studies, a systematic investigation of the compositionstructureproperty relationships of these high-atomic-number elpasolite halides was performed. The results reduce the barrier to commercialization of large single crystals or transparent ceramics, and will facilitate economical scale-up of elpasolites for high-sensitivity gamma-ray spectroscopy.

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Results 26–50 of 101
Results 26–50 of 101