Application of Triple Coincidence for the Detection of Small Amounts of Special Nuclear Materials (open access)

Application of Triple Coincidence for the Detection of Small Amounts of Special Nuclear Materials

We constructed a device that measures two {gamma}-rays and one neutron from spontaneous fission and any resulting multiplication chains. It extends the associated particle technique based upon correlated counting of the multiplicity of gamma-rays and neutrons released in spontaneous- or neutron-induced fission. There are two advantages in incorporating a third detector in the design over the standard two-detector version. First, we found that random uncorrelated events dominate the background of coincident counting with a gamma-ray- and neutron-detector. These might be suppressed by requiring an additional coincidence. Second, the time history of gamma-ray emission between the two gamma-ray detectors is related to multiplication in the target media. Multiplication in highly enriched uranium is much greater than in depleted uranium.
Date: June 12, 2011
Creator: DIOSZEGI, I.; Salwen, C. & and Forman, L.
System: The UNT Digital Library
Ionic Liquids: Radiation Chemistry, Solvation Dynamics and Reactivity Patterns (open access)

Ionic Liquids: Radiation Chemistry, Solvation Dynamics and Reactivity Patterns

Ionic liquids (ILs) are a rapidly expanding family of condensed-phase media with important applications in energy production, nuclear fuel and waste processing, improving the efficiency and safety of industrial chemical processes, and pollution prevention. ILs generally have low volatilities and are combustion-resistant, highly conductive, recyclable and capable of dissolving a wide variety of materials. They are finding new uses in chemical synthesis, catalysis, separations chemistry, electrochemistry and other areas. Ionic liquids have dramatically different properties compared to conventional molecular solvents, and they provide a new and unusual environment to test our theoretical understanding of primary radiation chemistry, charge transfer and other reactions. We are interested in how IL properties influence physical and dynamical processes that determine the stability and lifetimes of reactive intermediates and thereby affect the courses of reactions and product distributions. We study these issues by characterization of primary radiolysis products and measurements of their yields and reactivity, quantification of electron solvation dynamics and scavenging of electrons in different states of solvation. From this knowledge we wish to learn how to predict radiolytic mechanisms and control them or mitigate their effects on the properties of materials used in nuclear fuel processing, for example, and to apply IL radiation …
Date: June 12, 2011
Creator: Wishart, J. F.
System: The UNT Digital Library
Evaporation kinetics of laser heated silica in reactive and inert gases based on near-equilibrium dynamics (open access)

Evaporation kinetics of laser heated silica in reactive and inert gases based on near-equilibrium dynamics

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Date: June 12, 2011
Creator: Elhadj, S; Matthews, M J; Yang, S T & Cooke, D
System: The UNT Digital Library