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Development and Test of a Single-Aperture 11 T Nb3Sn Demonstrator Dipole for LHC Upgrades. (open access)

Development and Test of a Single-Aperture 11 T Nb3Sn Demonstrator Dipole for LHC Upgrades.

The upgrade of the LHC collimation system expects installation of additional collimators in the dispersion suppressor areas around the LHC ring. The longitudinal space for the collimators could be provided by replacing some 8.33 T Nb-Ti LHC main dipoles with shorter 11 T Nb/sub 3/Sn dipoles compatible with the LHC lattice and main systems. To demonstrate this possibility FNAL and CERN have started a joint program with the goal of building a 5.5 m long twin-aperture dipole prototype suitable for installation in the LHC. The first step of this program is the development of a 2 m long single-aperture demonstrator dipole with the nominal field of 11 T at the LHC nominal current of 11.85 kA and 60 mm bore with ~20% margin. This paper describes the design, construction and test results of the first single-aperture Nb/sub 3/Sn demonstrator dipole model.
Date: October 1, 2012
Creator: Zlobin, A.V. & al., et
System: The UNT Digital Library
Improved Neutronics Treatment of Burnable Poisons for the Prismatic HTR (open access)

Improved Neutronics Treatment of Burnable Poisons for the Prismatic HTR

In prismatic block High Temperature Reactors (HTR), highly absorbing material such a burnable poison (BP) cause local flux depressions and large gradients in the flux across the blocks which can be a challenge to capture accurately with traditional homogenization methods. The purpose of this paper is to quantify the error associated with spatial homogenization, spectral condensation and discretization and to highlight what is needed for improved neutronics treatments of burnable poisons for the prismatic HTR. A new triangular based mesh is designed to separate the BP regions from the fuel assembly. A set of packages including Serpent (Monte Carlo), Xuthos (1storder Sn), Pronghorn (diffusion), INSTANT (Pn) and RattleSnake (2ndorder Sn) is used for this study. The results from the deterministic calculations show that the cross sections generated directly in Serpent are not sufficient to accurately reproduce the reference Monte Carlo solution in all cases. The BP treatment produces good results, but this is mainly due to error cancellation. However, the Super Cell (SC) approach yields cross sections that are consistent with cross sections prepared on an “exact” full core calculation. In addition, very good agreement exists between the various deterministic transport and diffusion codes in both eigenvalue and power distributions. …
Date: October 1, 2012
Creator: Wang, Y.; Bingham, A. A.; Ortensi, J. & Permann, C. J.
System: The UNT Digital Library
Still Processing Tons of Data with QuickView (open access)

Still Processing Tons of Data with QuickView

This slide show is about data analysis for photonic Doppler velocimetry.
Date: October 21, 2012
Creator: Diaz, A. B.
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

N/A
Date: October 21, 2012
Creator: F., Wishart J.
System: The UNT Digital Library
D = 5 Maximally Supersymmetric Yang-Mills Theory Diverges at Six Loops (open access)

D = 5 Maximally Supersymmetric Yang-Mills Theory Diverges at Six Loops

None
Date: October 31, 2012
Creator: Bern, Zvi; Carrasco, John Joseph; Dixon, Lance J.; Douglas, Michael R.; von Hippel, Matt & Johansson, Henrik
System: The UNT Digital Library
Characterizing the behavior of bandwidth-bound applications on torus networks (open access)

Characterizing the behavior of bandwidth-bound applications on torus networks

None
Date: October 1, 2012
Creator: Jain, N; Bhatele, A; Menon, H; Gamblin, T; Schulz, M & Kale, L V
System: The UNT Digital Library
Current and Planned High Proton Flux Operations at the FNAL Booster (open access)

Current and Planned High Proton Flux Operations at the FNAL Booster

None
Date: October 1, 2012
Creator: Garcia, F. G. & Pellico, W.
System: The UNT Digital Library
Importance of Final-State Fluctuations in Radiative Capture Reactions and Applications to Surrogate Reaction Measurements (open access)

Importance of Final-State Fluctuations in Radiative Capture Reactions and Applications to Surrogate Reaction Measurements

None
Date: October 10, 2012
Creator: Dietrich, F S
System: The UNT Digital Library
Phase Competition in Trisected Superconducting Dome (open access)

Phase Competition in Trisected Superconducting Dome

None
Date: October 2, 2012
Creator: Vishik, I.M.; Hashimoto, M; He, Rui-Hua; Lee, Wei-Sheng; Schmitt, Felix; Lu, Donghui et al.
System: The UNT Digital Library
Clinical Trials of ProxiScan Compact Gamma Camera in Prostate Cancer Diagnosis (open access)

Clinical Trials of ProxiScan Compact Gamma Camera in Prostate Cancer Diagnosis

N/A
Date: October 29, 2012
Creator: Y., Cui
System: The UNT Digital Library
Plasma blobs and filaments -- fusion scientists discover secrets of turbulent edge transport (open access)

Plasma blobs and filaments -- fusion scientists discover secrets of turbulent edge transport

None
Date: October 18, 2012
Creator: Cohen, B I; Myra, J; Garcia, O E; Smith, D & Parker, S E
System: The UNT Digital Library
Superconducting Solenoid Lens for a High Energy Part of a Proton Linac Front End (open access)

Superconducting Solenoid Lens for a High Energy Part of a Proton Linac Front End

None
Date: October 1, 2012
Creator: DiMarco, E. J.; Orris, D. F.; Tartaglia, M. A.; Terechkine, I. & Khabiboulline, E.
System: The UNT Digital Library
Desiccant Enhanced Evaporative Air Conditioning: Parametric Analysis and Design; Preprint (open access)

Desiccant Enhanced Evaporative Air Conditioning: Parametric Analysis and Design; Preprint

This paper presents a parametric analysis using a numerical model of a new concept in desiccant and evaporative air conditioning. The concept consists of two stages: a liquid desiccant dehumidifier and a dew-point evaporative cooler. Each stage consists of stacked air channel pairs separated by a plastic sheet. In the first stage, a liquid desiccant film removes moisture from the process (supply-side) air through a membrane. An evaporatively-cooled exhaust airstream on the other side of the plastic sheet cools the desiccant. The second-stage indirect evaporative cooler sensibly cools the dried process air. We analyze the tradeoff between device size and energy efficiency. This tradeoff depends strongly on process air channel thicknesses, the ratio of first-stage to second-stage area, and the second-stage exhaust air flow rate. A sensitivity analysis reiterates the importance of the process air boundary layers and suggests a need for increasing airside heat and mass transfer enhancements.
Date: October 1, 2012
Creator: Woods, J. & Kozubal, E.
System: The UNT Digital Library
Passive Measurement of Organic-Scintillator Neutron Signatures for Nuclear Safeguards Applications (open access)

Passive Measurement of Organic-Scintillator Neutron Signatures for Nuclear Safeguards Applications

At nuclear facilities, domestically and internationally, most measurement systems used for nuclear materials’ control and accountability rely on He-3 detectors. Due to resource shortages, alternatives to He-3 systems are needed. This paper presents preliminary simulation and experimental efforts to develop a fast-neutron-multiplicity counter based on liquid organic scintillators. This mission also provides the opportunity to broaden the capabilities of such safeguards measurement systems to improve current neutron-multiplicity techniques and expand the scope to encompass advanced nuclear fuels.
Date: October 1, 2012
Creator: Dolan, Jennfier L.; Miller, Eric C.; Kaplan, Alexis C.; Enqvist, Andreas; Flaska, Marek; Tomanin, Alice et al.
System: The UNT Digital Library
Advanced Test Reactor National Scientific User Facility Progress (open access)

Advanced Test Reactor National Scientific User Facility Progress

The Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL) is one of the world’s premier test reactors for studying the effects of intense neutron radiation on reactor materials and fuels. The ATR began operation in 1967, and has operated continuously since then, averaging approximately 250 operating days per year. The combination of high flux, large test volumes, and multiple experiment configuration options provide unique testing opportunities for nuclear fuels and material researchers. The ATR is a pressurized, light-water moderated and cooled, beryllium-reflected highly-enriched uranium fueled, reactor with a maximum operating power of 250 MWth. The ATR peak thermal flux can reach 1.0 x1015 n/cm2-sec, and the core configuration creates five main reactor power lobes (regions) that can be operated at different powers during the same operating cycle. In addition to these nine flux traps there are 68 irradiation positions in the reactor core reflector tank. The test positions range from 0.5” to 5.0” in diameter and are all 48” in length, the active length of the fuel. The INL also has several hot cells and other laboratories in which irradiated material can be examined to study material radiation effects. In 2007 the US Department of Energy (DOE) designated …
Date: October 1, 2012
Creator: Marshall, Frances M.; Allen, Todd R.; Cole, James I.; Benson, Jeff B. & Thelen, Mary Catherine
System: The UNT Digital Library
Recent Progress in the NSTX/NSTX-U Lithium Program and Prospects for Reactor-Relevant Liquid-Lithium Based Divertor Development (open access)

Recent Progress in the NSTX/NSTX-U Lithium Program and Prospects for Reactor-Relevant Liquid-Lithium Based Divertor Development

Developing a reactor compatible divertor has been identified as a particularly challenging technology problem for magnetic confinement fusion. While tungsten has been identified as the most attractive solid divertor material, the NSTX/NSTX-U lithium (Li) program is investigating the viability of liquid lithium (LL) as a potential reactor compatible divertor plasma facing component (PFC) . In the near term, operation in NSTX-U is projected to provide reactor-like divertor heat loads < 40 MW/m^2 for 5 s. During the most recent NSTX campaign, ~ 0.85 kg of Li was evaporated onto the NSTX PFCs where a ~50% reduction in heat load on the Liquid Lithium Divertor (LLD) was observed, attributable to enhanced divertor bolometric radiation. This reduced divertor heat flux through radiation observed in the NSTX LLD experiment is consistent with the results from other lithium experiments and calculations. These results motivate an LL-based closed radiative divertor concept proposed here for NSTX-U and fusion reactors. With an LL coating, the Li is evaporated from the divertor strike point surface due to the intense heat. The evaporated Li is readily ionized by the plasma due to its low ionization energies, and the ionized Li ions can radiate strongly, resulting in a significant reduction …
Date: October 27, 2012
Creator: M. Ono, et al.
System: The UNT Digital Library
Battery Wear from Disparate Duty-Cycles: Opportunities for Electric-Drive Vehicle Battery Health Management; Preprint (open access)

Battery Wear from Disparate Duty-Cycles: Opportunities for Electric-Drive Vehicle Battery Health Management; Preprint

Electric-drive vehicles utilizing lithium-ion batteries experience wholly different degradation patterns than do conventional vehicles, depending on geographic ambient conditions and consumer driving and charging patterns. A semi-empirical life-predictive model for the lithium-ion graphite/nickel-cobalt-aluminum chemistry is presented that accounts for physically justified calendar and cycling fade mechanisms. An analysis of battery life for plug-in hybrid electric vehicles considers 782 duty-cycles from travel survey data superimposed with climate data from multiple geographic locations around the United States. Based on predicted wear distributions, opportunities for extending battery life including modification of battery operating limits, thermal and charge control are discussed.
Date: October 1, 2012
Creator: Smith, K.; Earleywine, M.; Wood, E. & Pesaran, A.
System: The UNT Digital Library
Life Cycle Environmental Impacts Resulting from the Manufacture of the Heliostat Field for a Reference Power Tower Design in the United States: Preprint (open access)

Life Cycle Environmental Impacts Resulting from the Manufacture of the Heliostat Field for a Reference Power Tower Design in the United States: Preprint

Life cycle assessment (LCA) is recognized as a useful analytical approach for quantifying environmental impacts of renewable energy technologies, including concentrating solar power (CSP). An LCA accounts for impacts from all stages in the development, operation, and decommissioning of a CSP plant, including such upstream stages as the extraction of raw materials used in system components, manufacturing of those components, and construction of the plant. The National Renewable Energy Laboratory is conducting a series of LCA studies for various CSP technologies. This paper contributes to a thorough LCA of a 100 MWnet molten salt power tower CSP plant by estimating the environmental impacts resulting from the manufacture of heliostats. Three life cycle metrics are evaluated: greenhouse gas emissions, water consumption, and cumulative energy demand. The heliostat under consideration (the 148 m2 Advanced Thermal Systems heliostat) emits 5,300 kg CO2eq, consumes 274 m3 of water, and requires 159,000 MJeq during its manufacture. Future work will incorporate the results from this study into the LCA model used to estimate the life cycle impacts of the entire 100 MWnet power tower CSP plant.
Date: October 1, 2012
Creator: Heath, G.; Burkhardt, J. & Turchi, C.
System: The UNT Digital Library
Challenges in the design of the detector solenoid for the Mu2e experiment (open access)

Challenges in the design of the detector solenoid for the Mu2e experiment

None
Date: October 1, 2012
Creator: Ostojic, R.; /CERN; Coleman, R.; Fang, I.; Lamm, M.; Miller, J. et al.
System: The UNT Digital Library
Status of the NGNP Graphite Creep Experiments AGC-1 and AGC-2 Irradiated in the Advanced Test Reactor (open access)

Status of the NGNP Graphite Creep Experiments AGC-1 and AGC-2 Irradiated in the Advanced Test Reactor

The United States Department of Energy’s Next Generation Nuclear Plant (NGNP) Program will be irradiating six nuclear graphite creep experiments in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). The graphite experiments will be irradiated over the next six to eight years to support development of a graphite irradiation performance data base on the new nuclear grade graphites now available for use in high temperature gas reactors. The goals of the irradiation experiments are to obtain irradiation performance data, including irradiation creep, at different temperatures and loading conditions to support design of the Next Generation Nuclear Plant (NGNP) Very High Temperature Gas Reactor, as well as other future gas reactors. The experiments will each consist of a single capsule that will contain six peripheral stacks of graphite specimens, with half of the graphite specimens in each stack under a compressive load, while the other half of the specimens will not be subjected to a compressive load during irradiation. The six peripheral stacks will have different compressive loads applied to the top half of each pair of specimen stacks, while a seventh stack will not have a compressive load. The specimens will be irradiated in an inert …
Date: October 1, 2012
Creator: Grover, S.Blaine
System: The UNT Digital Library
Quench Protection Study of a Single-Aperture 11 T Nb3Sn Demonstrator Dipole for LHC Upgrades (open access)

Quench Protection Study of a Single-Aperture 11 T Nb3Sn Demonstrator Dipole for LHC Upgrades

None
Date: October 1, 2012
Creator: Chlachidze, G. & al., et
System: The UNT Digital Library
Modeling of an Interwoven Collimator in a Gamma Camera for Intr-body-Cavity Applications (open access)

Modeling of an Interwoven Collimator in a Gamma Camera for Intr-body-Cavity Applications

N/A
Date: October 29, 2012
Creator: Y., Cui
System: The UNT Digital Library
Investigation of Some Transparent Metal Oxides as Damp Heat Protective Coating for CIGS Solar Cells: Preprint (open access)

Investigation of Some Transparent Metal Oxides as Damp Heat Protective Coating for CIGS Solar Cells: Preprint

We investigated the protective effectiveness of some transparent metal oxides (TMO) on CIGS solar cell coupons against damp heat (DH) exposure at 85oC and 85% relative humidity (RH). Sputter-deposited bilayer ZnO (BZO) with up to 0.5-um Al-doped ZnO (AZO) layer and 0.2-um bilayer InZnO were used as 'inherent' part of device structure on CdS/CIGS/Mo/SLG. Sputter-deposited 0.2-um ZnSnO and atomic layer deposited (ALD) 0.1-um Al2O3 were used as overcoat on typical BZO/CdS/CIGS/Mo/SLG solar cells. The results were all negative -- all TMO-coated CIGS cells exhibited substantial degradation in DH. Combining the optical photographs, PL and EL imaging, SEM surface micro-morphology, coupled with XRD, I-V and QE measurements, the causes of the device degradations are attributed to hydrolytic corrosion, flaking, micro-cracking, and delamination induced by the DH moisture. Mechanical stress and decrease in crystallinity (grain size effect) could be additional degrading factors for thicker AZO grown on CdS/CIGS.
Date: October 1, 2012
Creator: Pern, F. J.; Yan, F.; Zaaunbrecher, B.; To, B.; Perkins, J. & Noufi, R.
System: The UNT Digital Library
Semileptonic Decays (open access)

Semileptonic Decays

The following is an overview of the measurements of the CKM matrix elements |V{sub cb}| and |V{sub ub}| that are based on detailed studies of semileptonic B decays by the BABAR and Belle Collaborations and major advances in QCD calculations. In addition, a new and improved measurement of the ratios R(D{sup (*)}) = {Beta}({bar B} {yields} D{sup (*)}{tau}{sup -}{bar {nu}}{sub {tau}})/{Beta}({bar B} {yields} D{sup (*)}{ell}{sup -}{bar {nu}}{sub {ell}}) is presented. Here D{sup (*)} refers to a D or a D* meson and {ell} is either e or {mu}. The results, R(D) = 0.440 {+-} 0.058 {+-} 0.042 and R(D*) = 0.332 {+-} 0.024 {+-} 0.018, exceed the Standard Model expectations by 2.0{sigma} and 2.7{sigma}, respectively. Taken together, they disagree with these expectations at the 3.4{sigma} level. The excess of events cannot be explained by a charged Higgs boson in the type II two-Higgs-doublet model.
Date: October 2, 2012
Creator: Luth, Vera G.
System: The UNT Digital Library