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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, Fred P.; Zhou, Xiaowang Z.; Deng, Haoran D.; 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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TYPE Journal Article YEAR 2013
OSTIDOI

Petrologic and petrophysical evaluation of the Dallas Center Structure, Iowa, for compressed air energy storage in the Mount Simon Sandstone

Heath, Jason; Bauer, Stephen J.; Broome, Scott T.; Dewers, Thomas D.; Rodriguez, Marko A.

The Iowa Stored Energy Plant Agency selected a geologic structure at Dallas Center, Iowa, for evaluation of subsurface compressed air energy storage. The site was rejected due to lower-than-expected and heterogeneous permeability of the target reservoir, lower-than-desired porosity, and small reservoir volume. In an initial feasibility study, permeability and porosity distributions of flow units for the nearby Redfield gas storage field were applied as analogue values for numerical modeling of the Dallas Center Structure. These reservoir data, coupled with an optimistic reservoir volume, produced favorable results. However, it was determined that the Dallas Center Structure cannot be simplified to four zones of high, uniform permeabilities. Updated modeling using field and core data for the site provided unfavorable results for air fill-up. This report presents Sandia National Laboratories petrologic and petrophysical analysis of the Dallas Center Structure that aids in understanding why the site was not suitable for gas storage.

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TYPE SAND Report YEAR 2013
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Elpasolite scintillators

Doty, Fred P.; Yang, Pin Y.; Zhou, Xiaowang Z.; Rodriguez, Marko 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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TYPE SAND Report YEAR 2012
OSTIDOI
Results 26–50 of 220
Results 26–50 of 220