Scintillation and Luminescence Properties of Undoped and Cerium-doped LiGdCl4 and NaGdCl4 (open access)

Scintillation and Luminescence Properties of Undoped and Cerium-doped LiGdCl4 and NaGdCl4

We report the scintillation properties of the undoped and cerium-doped variations of LiGdCl4 and NaGdCl4. Powder samples of these materials exhibit significant scintillation under X-rays. The samples were synthesized by solid-state methods from a 1:1 molar ratio of lithium or sodium chloride and gadolinium chloride. Cerium trichloride was used as the dopant. The physical, optical, and scintillation properties of these materials were analyzed by powder X-ray diffraction, photoluminescence, X-ray excited luminescence, and pulsed X-ray luminosity measurements. Increases in light yields are observed as the concentration of cerium increases. The highest light yields occurred at 20 percent cerium doping for both compounds. At larger concentrations neither compound formed, indicating a breakdown of the lattice with the addition of large amounts of cerium cations. At 20 percent cerium, LiGdCl4 and NaGdCl4 display scintillation light 3.6 times and 2.2 times the light yield of the reference material, YAlO3:Ce3+, respectively. Both emit in the ranges of 340 ? 350 nm and 365 - 370 nm and display multiexponential decays with cerium-like decay components at 33 ns (LiGdCl4:Ce) and 26 ns (NaGdCl4:Ce).
Date: October 5, 2008
Creator: Porter-Chapman, Yetta D.; Bourret-Courchesne, Edith D.; Bizarri, Gregory; Weber, Marvin J. & Derenzo, Stephen E.
Object Type: Article
System: The UNT Digital Library
Transition Plan for the K-1203 Sewage Treatment Plant, East Tennessee Technology Park, Oak Ridge, Tennessee (open access)

Transition Plan for the K-1203 Sewage Treatment Plant, East Tennessee Technology Park, Oak Ridge, Tennessee

The K-1203 Sewage Treatment Plant (STP) was previously used to treat and process all sanitary sewage waste from the East Tennessee Technology Park (ETTP). The plant was shut down on May 29, 2008 as a result of the transition of sewage treatment for ETTP to the City of Oak Ridge. The City of Oak Ridge expanded the Rarity Ridge Sewage Treatment Plant (RRSTP) to include capacity to treat the waste from the ETTP and the Community Reuse Organization of East Tennessee (CROET) constructed a new ETTP lift station and force main to RRSTP. In preparation for the shutdown of K-1203, the US Department of Energy (DOE) in conjunction with Operation Management International (OMI) developed a shut down plan to outline actions that need to occur prior to the transition of the facility to Bechtel Jacob Company, LLC (BJC) for decontamination and demolition (D and D). This plan outlines the actions, roles, and responsibilities for BJC in order to support the transition of the K-1203 STP from OMI to the BJC Surveillance and Maintenance (S and M) and D and D programs. The D and D of the K-1203 Facilities is planned under the Comprehensive Environmental Response, Compensation, and Liability Act …
Date: October 5, 2008
Creator: J., Hoffmeister
Object Type: Report
System: The UNT Digital Library