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Neutrino-nucleus interactions (open access)

Neutrino-nucleus interactions

The study of neutrino oscillations has necessitated a new generation of neutrino experiments that are exploring neutrino-nuclear scattering processes. We focus in particular on charged-current quasi-elastic scattering, a particularly important channel that has been extensively investigated both in the bubble-chamber era and by current experiments. Recent results have led to theoretical reexamination of this process. We review the standard picture of quasi-elastic scattering as developed in electron scattering, review and discuss experimental results, and discuss additional nuclear effects such as exchange currents and short-range correlations that may play a significant role in neutrino-nucleus scattering.
Date: January 1, 2011
Creator: Gallagher, H.; Garvey, G. & Zeller, G. P.
System: The UNT Digital Library
LESSONS LEARNED FROM A RECENT LASER ACCIDENT (open access)

LESSONS LEARNED FROM A RECENT LASER ACCIDENT

A graduate student received a laser eye injury from a femtosecond Ti:sapphire laser beam while adjusting a polarizing beam splitter optic. The direct causes for the accident included failure to follow safe alignment practices and failure to wear the required laser eyewear protection. Underlying root causes included inadequate on-the-job training and supervision, inadequate adherence to requirements, and inadequate appreciation for dimly visible beams outside the range of 400-700nm. This paper describes how the accident occurred, discusses causes and lessons learned, and describes corrective actions being taken.
Date: January 26, 2011
Creator: Woods, Michael
System: The UNT Digital Library
Laser Safety: A Laser Alignment Practical Training Course (open access)

Laser Safety: A Laser Alignment Practical Training Course

SLAC National Accelerator Laboratory has developed a Laser Alignment Practical Training Course as one of its core laser safety classes. The course is taught to small groups of up to three students and takes 1-3 hours to complete. This practical course is not a substitute for site-specific On-the-Job Training; it does, however, provide a good introduction in core laser safety practices that can be broadly applied. Alignment and diagnostic tasks are performed with low power lasers. Students learn safe alignment and diagnostic techniques and how to avoid common mistakes that might lead to an accident. The class is taught by laser supervisors, enabling them to assess the skill level of new laser personnel and determine the subsequent level of supervision needed. The course has six alignment tasks. For each task, discussion points are given for the instructor to review with the students. The optics setup includes different wavelength lasers, a beam expander, mirrors, irises, a periscope, a beam-splitting polarizer and a diffraction grating. Diagnostic tools include viewing cards, an IR viewer and a ccd camera. Laser eyewear is available to block some laser wavelengths in the setup.
Date: January 26, 2011
Creator: Woods, Michael & Edstrom, Steve
System: The UNT Digital Library
Evidence for a Mass Dependent Forward-Backward Asymmetry in Top Quark Pair Production (open access)

Evidence for a Mass Dependent Forward-Backward Asymmetry in Top Quark Pair Production

We present a new measurement of the inclusive forward-backward t{bar t} production asymmetry and its rapidity and mass dependence. The measurements are performed with data corresponding to an integrated luminosity of 5.3 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV, recorded with the CDF II Detector at the Fermilab Tevatron. Significant inclusive asymmetries are observed in both the laboratory frame and the t{bar t} rest frame, and in both cases are found to be consistent with CP conservation under interchange of t and {bar t}. In the t{bar t} rest frame, the asymmetry is observed to increase with the t{bar t} rapidity difference, {Delta}y, and with the invariant mass M{sub t{bar t}} of the t{bar t} system. Fully corrected parton-level asymmetries are derived in two regions of each variable, and the asymmetry is found to be most significant at large {Delta}y and M{sub t{bar t}}. For M{sub t{bar t}} {ge} 450 GeV/c{sup 2}, the parton-level asymmetry in the t{bar t} rest frame is A{sup t{bar t}} = 0.475 {+-} 0.114 compared to a next-to-leading order QCD prediction of 0.088 {+-} 0.013.
Date: January 1, 2011
Creator: Aaltonen, T.; Phys., /Helsinki Inst. of; Alvarez Gonzalez, B.; Phys., /Cantabria Inst. of; Amerio, S.; /INFN, Padua et al.
System: The UNT Digital Library
Heavy hadron spectroscopy at CDF (open access)

Heavy hadron spectroscopy at CDF

We present recent CDF results on the properties of hadrons containing heavy quarks. These include measurements of charm and {Sigma}{sub b}{sup -}{Sigma}*{sub b}{sup -} baryon's masses, lifetimes and masses of {Omega}{sub b}{sup -}, {Xi}{sub b}{sup -} and B{sub c}{sup -} and a measurement of exclusive B{sup +}, B{sup 0} and {Lambda}{sub b} lifetimes as well as lifetime ratios (charge conjugate modes are implied throughout the text). We also summarize new measurements of exotic particles X(3872) and Y(4140).
Date: January 1, 2011
Creator: Fernandez Ramos, Juan Pablo & /Madrid, CIEMAT
System: The UNT Digital Library
QCD Results from the Tevatron (open access)

QCD Results from the Tevatron

None
Date: January 1, 2011
Creator: Bandurin, Dmitry V.
System: The UNT Digital Library
Optimization of the safety factor profile for high noninductive current fraction discharges in DIII-D (open access)

Optimization of the safety factor profile for high noninductive current fraction discharges in DIII-D

None
Date: January 19, 2011
Creator: Ferron, J.; Holcomb, C.; Luce, T.; Politzer, P.; Turco, F.; White, A. et al.
System: The UNT Digital Library
A high-order finite-volume method for hyperbolic conservation laws on locally-refined grids (open access)

A high-order finite-volume method for hyperbolic conservation laws on locally-refined grids

We present a fourth-order accurate finite-volume method for solving time-dependent hyperbolic systems of conservation laws on Cartesian grids with multiple levels of refinement. The underlying method is a generalization of that in [5] to nonlinear systems, and is based on using fourth-order accurate quadratures for computing fluxes on faces, combined with fourth-order accurate Runge?Kutta discretization in time. To interpolate boundary conditions at refinement boundaries, we interpolate in time in a manner consistent with the individual stages of the Runge-Kutta method, and interpolate in space by solving a least-squares problem over a neighborhood of each target cell for the coefficients of a cubic polynomial. The method also uses a variation on the extremum-preserving limiter in [8], as well as slope flattening and a fourth-order accurate artificial viscosity for strong shocks. We show that the resulting method is fourth-order accurate for smooth solutions, and is robust in the presence of complex combinations of shocks and smooth flows.
Date: January 28, 2011
Creator: McCorquodale, Peter & Colella, Phillip
System: The UNT Digital Library
SDSS-III: Massive Spectroscopic Surveys of the Distant Universe, the Milky Way Galaxy, and Extra-Solar Planetary Systems (open access)

SDSS-III: Massive Spectroscopic Surveys of the Distant Universe, the Milky Way Galaxy, and Extra-Solar Planetary Systems

Building on the legacy of the Sloan Digital Sky Survey (SDSS-I and II), SDSS-III is a program of four spectroscopic surveys on three scientific themes: dark energy and cosmological parameters, the history and structure of the Milky Way, and the population of giant planets around other stars. The Baryon Oscillation Spectroscopic Survey (BOSS) will measure redshifts of 1.5 million massive galaxies and Ly{alpha} forest spectra of 150,000 quasars, using the baryon acoustic oscillation (BAO) feature of large scale structure to obtain percent-level determinations of the distance scale and Hubble expansion rate at z < 0.7 and at z {approx} 2.5. SEGUE-2, a now-completed continuation of the Sloan Extension for Galactic Understanding and Exploration, measured medium-resolution (R = {lambda}/{Delta}{lambda} 1800) optical spectra of 118,000 stars in a variety of target categories, probing chemical evolution, stellar kinematics and substructure, and the mass profile of the dark matter halo from the solar neighborhood to distances of 100 kpc. APOGEE, the Apache Point Observatory Galactic Evolution Experiment, will obtain high-resolution (R {approx} 30,000), high signal-to-noise ratio (S/N {ge} 100 per resolution element), H-band (1.51 {micro}m < {lambda} < 1.70 {micro}m) spectra of 10{sup 5} evolved, late-type stars, measuring separate abundances for {approx} 15 elements …
Date: January 1, 2011
Creator: Eisenstein, Daniel J.; Weinberg, David H.; Agol, Eric; Aihara, Hiroaki; Prieto, Carlos Allende; Anderson, Scott F. et al.
System: The UNT Digital Library
Vertically integrated pixel readout chip for high energy physics (open access)

Vertically integrated pixel readout chip for high energy physics

We report on the development of the vertex detector pixel readout chips based on multi-tier vertically integrated electronics for the International Linear Collider. Some testing results of the VIP2a prototype are presented. The chip is the second iteration of the silicon implementation of the prototype, data-pushed concept of the readout developed at Fermilab. The device was fabricated in the 3D MIT-LL 0.15 {micro}m fully depleted SOI process. The prototype is a three-tier design, featuring 30 x 30 {micro}m{sup 2} pixels, laid out in an array of 48 x 48 pixels.
Date: January 1, 2011
Creator: Deptuch, Grzegorz; Demarteau, Marcel; Hoff, James; Khalid, Farah; Lipton, Ronald; Shenai, Alpana et al.
System: The UNT Digital Library
Application of Distribution Transformer Thermal Life Models to Electrified Vehicle Charging Loads Using Monte-Carlo Method: Preprint (open access)

Application of Distribution Transformer Thermal Life Models to Electrified Vehicle Charging Loads Using Monte-Carlo Method: Preprint

Concentrated purchasing patterns of plug-in vehicles may result in localized distribution transformer overload scenarios. Prolonged periods of transformer overloading causes service life decrements, and in worst-case scenarios, results in tripped thermal relays and residential service outages. This analysis will review distribution transformer load models developed in the IEC 60076 standard, and apply the model to a neighborhood with plug-in hybrids. Residential distribution transformers are sized such that night-time cooling provides thermal recovery from heavy load conditions during the daytime utility peak. It is expected that PHEVs will primarily be charged at night in a residential setting. If not managed properly, some distribution transformers could become overloaded, leading to a reduction in transformer life expectancy, thus increasing costs to utilities and consumers. A Monte-Carlo scheme simulated each day of the year, evaluating 100 load scenarios as it swept through the following variables: number of vehicle per transformer, transformer size, and charging rate. A general method for determining expected transformer aging rate will be developed, based on the energy needs of plug-in vehicles loading a residential transformer.
Date: January 1, 2011
Creator: Kuss, M.; Markel, T. & Kramer, W.
System: The UNT Digital Library
Measurement of $\phi_s$ at D{\O} Experiment (open access)

Measurement of $\phi_s$ at D{\O} Experiment

Recent measurements of the D0 experiment related to the search for new phenomena beyond the Standard Model are reviewed. The new measurement of the like-sign dimuon charge asymmetry reveals a 3.2{sigma} deviation from the SM prediction, while the updated study of the B{sub s} {yields} J/{psi}{phi} decay demonstrates a better agreement with the SM. All experimental results on the CP violation in mixing are currently consistent with each other. The D0 collaboration has much more statistics to analyze, and all these results can be significantly improved in the future.
Date: January 1, 2011
Creator: Borissov, G.
System: The UNT Digital Library
Estimating High Level Waste Mixing Performance in Hanford Double Shell Tanks (open access)

Estimating High Level Waste Mixing Performance in Hanford Double Shell Tanks

The ability to effectively mix, sample, certify, and deliver consistent batches of high level waste (HLW) feed from the Hanford double shell tanks (DSTs) to the Waste Treatment and Immobilization Plant (WTP) presents a significant mission risk with potential to impact mission length and the quantity of HLW glass produced. The Department of Energy's (DOE's) Tank Operations Contractor (TOC), Washington River Protection Solutions (WRPS) is currently demonstrating mixing, sampling, and batch transfer performance in two different sizes of small-scale DSTs. The results of these demonstrations will be used to estimate full-scale DST mixing performance and provide the key input to a programmatic decision on the need to build a dedicated feed certification facility. This paper discusses the results from initial mixing demonstration activities and presents data evaluation techniques that allow insight into the performance relationships of the two small tanks. The next steps, sampling and batch transfers, of the small scale demonstration activities are introduced. A discussion of the integration of results from the mixing, sampling, and batch transfer tests to allow estimating full-scale DST performance is presented.
Date: January 13, 2011
Creator: Thien, M. G.; Greer, D. A. & Townson, P.
System: The UNT Digital Library
Horizontally scaling dCache SRM with the Terracotta platform (open access)

Horizontally scaling dCache SRM with the Terracotta platform

The dCache disk caching file system has been chosen by a majority of LHC experiments Tier 1 centers for their data storage needs. It is also deployed at many Tier 2 centers. The Storage Resource Manager (SRM) is a standardized grid storage interface and a single point of remote entry into dCache, and hence is a critical component. SRM must scale to increasing transaction rates and remain resilient against changing usage patterns. The initial implementation of the SRM service in dCache suffered from an inability to support clustered deployment, and its performance was limited by the hardware of a single node. Using the Terracotta platform, we added the ability to horizontally scale the dCache SRM service to run on multiple nodes in a cluster configuration, coupled with network load balancing. This gives site administrators the ability to increase the performance and reliability of SRM service to face the ever-increasing requirements of LHC data handling. In this paper we will describe the previous limitations of the architecture SRM server and how the Terracotta platform allowed us to readily convert single node service into a highly scalable clustered application.
Date: January 1, 2011
Creator: Perelmutov, T.; Crawford, M.; Moibenko, A. & Oleynik, G.
System: The UNT Digital Library
Electronic Structure of CeFeAsO1-xFx (x=0, 0.11/x=0.12) compounds (open access)

Electronic Structure of CeFeAsO1-xFx (x=0, 0.11/x=0.12) compounds

We report an extensive study on the intrinsic bulk electronic structure of the high-temperature superconductor CeFeAsO{sub 0.89}F{sub 0.11} and its parent compound CeFeAsO by soft and hard x-ray photoemission, x-ray absorption and soft-x-ray emission spectroscopies. The complementary surface/bulk probing depth, and the elemental and chemical sensitivity of these techniques allows resolving the intrinsic electronic structure of each element and correlating it with the local structure, which has been probed by extended-x-ray absorption fine structure spectroscopy. The measurements indicate a predominant 4f{sup 1} (i.e. Ce{sup 3+}) initial state configuration for Cerium and an effective valence-band-to-4f charge-transfer screening of the core hole. The spectra also reveal the presence of a small Ce f{sup 0} initial state configuration, which we assign to the occurrence of an intermediate valence state. The data reveal a reasonably good agreement with the partial density of states as obtained in standard density functional calculations over a large energy range. Implications for the electronic structure of these materials are discussed.
Date: January 25, 2011
Creator: Bondino, F.; Magnano, E.; Booth, C. H.; Offi, F.; Panaccione, G.; Malvestuto, M. et al.
System: The UNT Digital Library
Accelerating Battery Design Using Computer-Aided Engineering Tools: Preprint (open access)

Accelerating Battery Design Using Computer-Aided Engineering Tools: Preprint

Computer-aided engineering (CAE) is a proven pathway, especially in the automotive industry, to improve performance by resolving the relevant physics in complex systems, shortening the product development design cycle, thus reducing cost, and providing an efficient way to evaluate parameters for robust designs. Academic models include the relevant physics details, but neglect engineering complexities. Industry models include the relevant macroscopic geometry and system conditions, but simplify the fundamental physics too much. Most of the CAE battery tools for in-house use are custom model codes and require expert users. There is a need to make these battery modeling and design tools more accessible to end users such as battery developers, pack integrators, and vehicle makers. Developing integrated and physics-based CAE battery tools can reduce the design, build, test, break, re-design, re-build, and re-test cycle and help lower costs. NREL has been involved in developing various models to predict the thermal and electrochemical performance of large-format cells and has used in commercial three-dimensional finite-element analysis and computational fluid dynamics to study battery pack thermal issues. These NREL cell and pack design tools can be integrated to help support the automotive industry and to accelerate battery design.
Date: January 1, 2011
Creator: Pesaran, A.; Heon, G. H. & Smith, K.
System: The UNT Digital Library
The Role of a Detailed Configuration Accounting (DCA) Atomic Physics Package in Explaing the Energy Balance in Ignition Scale Hohlraums (open access)

The Role of a Detailed Configuration Accounting (DCA) Atomic Physics Package in Explaing the Energy Balance in Ignition Scale Hohlraums

None
Date: January 10, 2011
Creator: Rosen, M; Scott, H; Hinkel, D; Williams, E; Callahan, D; Town, R et al.
System: The UNT Digital Library
Effect of Coal Properties and Operation Conditions on Flow Behavior of Coal Slag in Entrained Flow Gasifiers: A Brief Review (open access)

Effect of Coal Properties and Operation Conditions on Flow Behavior of Coal Slag in Entrained Flow Gasifiers: A Brief Review

Integrated gasification combined cycle (IGCC) is a potentially promising clean technology with an inherent advantage of low emissions, since the process removes contaminants before combustion instead of from flue gas after combustion, as in a conventional coal steam plant. In addition, IGCC has potential for cost-effective carbon dioxide capture. Availability and high capital costs are the main challenges to making IGCC technology more competitive and fully commercial. Experiences from demonstrated IGCC plants show that, in the gasification system, low availability is largely due to slag buildup in the gasifier and fouling in the syngas cooler downstream of the gasification system. In the entrained flow gasifiers used in IGCC plants, the majority of mineral matter transforms to liquid slag on the wall of the gasifier and flows out the bottom. However, a small fraction of the mineral matter (as fly ash) is entrained with the raw syngas out of the gasifier to downstream processing. This molten/sticky fly ash could cause fouling of the syngas cooler. Therefore, it is preferable to minimize the quantity of fly ash and maximize slag. In addition, the hot raw syngas is cooled to convert any entrained molten fly slag to hardened solid fly ash prior to …
Date: January 1, 2011
Creator: Wang,Ping & Massoudi, Mehrdad
System: The UNT Digital Library
Status of Nb3Sn accelerator magnet R&D at Fermilab (open access)

Status of Nb3Sn accelerator magnet R&D at Fermilab

None
Date: January 1, 2011
Creator: Zlobin, A.V.
System: The UNT Digital Library
Methodology for Calculating Cost-per-Mile for Current and Future Vehicle Powertrain Technologies, with Projections to 2024: Preprint (open access)

Methodology for Calculating Cost-per-Mile for Current and Future Vehicle Powertrain Technologies, with Projections to 2024: Preprint

Currently, several cost-per-mile calculators exist that can provide estimates of acquisition and operating costs for consumers and fleets. However, these calculators are limited in their ability to determine the difference in cost per mile for consumer versus fleet ownership, to calculate the costs beyond one ownership period, to show the sensitivity of the cost per mile to the annual vehicle miles traveled (VMT), and to estimate future increases in operating and ownership costs. Oftentimes, these tools apply a constant percentage increase over the time period of vehicle operation, or in some cases, no increase in direct costs at all over time. A more accurate cost-per-mile calculator has been developed that allows the user to analyze these costs for both consumers and fleets. The calculator was developed to allow simultaneous comparisons of conventional light-duty internal combustion engine (ICE) vehicles, mild and full hybrid electric vehicles (HEVs), and fuel cell vehicles (FCVs). This paper is a summary of the development by the authors of a more accurate cost-per-mile calculator that allows the user to analyze vehicle acquisition and operating costs for both consumer and fleets. Cost-per-mile results are reported for consumer-operated vehicles travelling 15,000 miles per year and for fleets travelling 25,000 …
Date: January 1, 2011
Creator: Ruth, M.; Timbario, T. A.; Timbario, T. J. & Laffen, M.
System: The UNT Digital Library
Electrically detected magnetic resonance in a W-band microwave cavity (open access)

Electrically detected magnetic resonance in a W-band microwave cavity

We describe a low-temperature sample probe for the electrical detection of magnetic resonance in a resonant W-band (94 GHz) microwave cavity. The advantages of this approach are demonstrated by experiments on silicon field-effect transistors. A comparison with conventional low-frequency measurements at X-band (9.7 GHz) on the same devices reveals an up to 100-fold enhancement of the signal intensity. In addition, resonance lines that are unresolved at X-band are clearly separated in the W-band measurements. Electrically detected magnetic resonance at high magnetic fields and high microwave frequencies is therefore a very sensitive technique for studying electron spins with an enhanced spectral resolution and sensitivity.
Date: January 14, 2011
Creator: Lang, V.; Lo, C. C.; George, R. E.; Lyon, S. A.; Bokor, J.; Schenkel, T. et al.
System: The UNT Digital Library
Structural stability of transparent conducting films assembled from length purified single-wall carbon nanotubes (open access)

Structural stability of transparent conducting films assembled from length purified single-wall carbon nanotubes

Single-wall carbon nanotube (SWCNT) films show significant promise for transparent electronics applications that demand mechanical flexibility, but durability remains an outstanding issue. In this work, thin membranes of length purified single-wall carbon nanotubes (SWCNTs) are uniaxially and isotropically compressed by depositing them on prestrained polymer substrates. Upon release of the strain, the topography, microstructure, and conductivity of the films are characterized using a combination of optical/fluorescence microscopy, light scattering, force microscopy, electron microscopy, and impedance spectroscopy. Above a critical surface mass density, films assembled from nanotubes of well-defined length exhibit a strongly nonlinear mechanical response. The measured strain dependence reveals a dramatic softening that occurs through an alignment of the SWCNTs normal to the direction of prestrain, which at small strains is also apparent as an anisotropic increase in sheet resistance along the same direction. At higher strains, the membrane conductivities increase due to a compression-induced restoration of conductive pathways. Our measurements reveal the fundamental mode of elasto-plastic deformation in these films and suggest how it might be suppressed.
Date: January 1, 2011
Creator: Harris, J. M.; Iyer, G. R. S.; Simien, D. O.; Fagan, J. A.; Huh, J. Y.; Chung, J. Y. et al.
System: The UNT Digital Library
Identifying the Sources of Nitrate to a Deep Municipal Water Supply Well Using Stable Isotopes of Nitrate, Groundwater Age Dating, and Depth-Specific Sampling (open access)

Identifying the Sources of Nitrate to a Deep Municipal Water Supply Well Using Stable Isotopes of Nitrate, Groundwater Age Dating, and Depth-Specific Sampling

None
Date: January 28, 2011
Creator: Singleton, M J; Gailey, R M; Moran, J E; Sutton, M C; Heller, N; Esser, B K et al.
System: The UNT Digital Library
PERFORMANCE IMPROVEMENT OF CROSS-FLOW FILTRATION FOR HIGH LEVEL WASTE TREATMENT (open access)

PERFORMANCE IMPROVEMENT OF CROSS-FLOW FILTRATION FOR HIGH LEVEL WASTE TREATMENT

In the interest of accelerating waste treatment processing, the DOE has funded studies to better understand filtration with the goal of improving filter fluxes in existing cross-flow equipment. The Savannah River National Laboratory (SRNL) was included in those studies, with a focus on start-up techniques, filter cake development, the application of filter aids (cake forming solid precoats), and body feeds (flux enhancing polymers). This paper discusses the progress of those filter studies. Cross-flow filtration is a key process step in many operating and planned waste treatment facilities to separate undissolved solids from supernate slurries. This separation technology generally has the advantage of self-cleaning through the action of wall shear stress created by the flow of waste slurry through the filter tubes. However, the ability of filter wall self-cleaning depends on the slurry being filtered. Many of the alkaline radioactive wastes are extremely challenging to filtration, e.g., those containing compounds of aluminum and iron, which have particles whose size and morphology reduce permeability. Unfortunately, low filter flux can be a bottleneck in waste processing facilities such as the Savannah River Modular Caustic Side Solvent Extraction Unit and the Hanford Waste Treatment Plant. Any improvement to the filtration rate would lead directly …
Date: January 12, 2011
Creator: Duignan, M.; Nash, C. & Poirier, M.
System: The UNT Digital Library