Edge Turbulence Velocity Changes with Lithium Coating on NSTX (open access)

Edge Turbulence Velocity Changes with Lithium Coating on NSTX

Lithium coating improves energy confinement and eliminates edge localized modes in NSTX, but the mechanism of this improvement is not yet well understood. We used the gas-puff-imaging (GPI) diagnostic on NSTX to measure the changes in edge turbulence which occurred during a scan with variable lithium wall coating, in order to help understand the reason for the confinement improvement with lithium. There was a small increase in the edge turbulence poloidal velocity and a decrease in the poloidal velocity fluctuation level with increased lithium. The possible effect of varying edge neutral density on turbulence damping was evaluated for these cases in NSTX. __________________________________________________
Date: August 10, 2012
Creator: A. Cao, S.J. Zweben, D.P. Stotler, M. Bell, A. Diallo, S.M. Kaye and B. LeBlanc
Object Type: Report
System: The UNT Digital Library
Potential for luminosity improvement for low-energy RHIC operation with long bunches (open access)

Potential for luminosity improvement for low-energy RHIC operation with long bunches

Electron cooling was proposed to increase luminosity of the RHIC collider for heavy ion beams at low energies. Luminosity decreases as the square of bunch intensity due to the beam loss from the RF bucket as a result of the longitudinal intra beam scattering (IBS), as well as due to the transverse emittance growth because of the transverse IBS. Both transverse and longitudinal IBS can be counteracted with electron cooling. This would allow one to keep the initial peak luminosity close to constant throughout the store essentially without the beam loss. In addition, the phase-space density of the hadron beams can be further increased by providing stronger electron cooling. Unfortunately, the defining limitation for low energies in RHIC is expected to be the space charge. Here we explore an idea of additional improvement in luminosity, on top of the one coming from just IBS compensation and longer stores, which may be expected if one can operate with longer bunches at the space-charge limit in a collider. This approach together with electron cooling may result in about 10-fold improvement in total luminosity for low-energy RHIC program.
Date: February 10, 2012
Creator: A., Fedotov; Blaskiewicz&#44 & M.
Object Type: Report
System: The UNT Digital Library
Luminosity Determination in pp Collisions at sqrt(s)=7 TeV Using the ATLAS Detector at the LHC (open access)

Luminosity Determination in pp Collisions at sqrt(s)=7 TeV Using the ATLAS Detector at the LHC

None
Date: June 10, 2013
Creator: Aad, Georges
Object Type: Article
System: The UNT Digital Library
LITERATURE REVIEW ON IMPACT OF GLYCOLATE ON THE 2H EVAPORATOR AND THE EFFLUENT TREATMENT FACILITY (open access)

LITERATURE REVIEW ON IMPACT OF GLYCOLATE ON THE 2H EVAPORATOR AND THE EFFLUENT TREATMENT FACILITY

Glycolic acid (GA) is being studied as an alternate reductant in the Defense Waste Processing Facility (DWPF) feed preparation process. It will either be a total or partial replacement for the formic acid that is currently used. A literature review has been conducted on the impact of glycolate on two post-DWPF downstream systems - the 2H Evaporator system and the Effluent Treatment Facility (ETF). The DWPF recycle stream serves as a portion of the feed to the 2H Evaporator. Glycolate enters the evaporator system from the glycolate in the recycle stream. The overhead (i.e., condensed phase) from the 2H Evaporator serves as a portion of the feed to the ETF. The literature search revealed that virtually no impact is anticipated for the 2H Evaporator. Glycolate may help reduce scale formation in the evaporator due to its high complexing ability. The drawback of the solubilizing ability is the potential impact on the criticality analysis of the 2H Evaporator system. It is recommended that at least a theoretical evaluation to confirm the finding that no self-propagating violent reactions with nitrate/nitrites will occur should be performed. Similarly, identification of sources of ignition relevant to glycolate and/or update of the composite flammability analysis to …
Date: May 10, 2012
Creator: Adu-Wusu, K.
Object Type: Report
System: The UNT Digital Library
Tetraquark Interpretation of $E^ E^- \to \Upsilon \pi^ \pi^-$ Belle Data and $E^ E^- \to B \bar{b}$ BaBar Data (open access)

Tetraquark Interpretation of $E^ E^- \to \Upsilon \pi^ \pi^-$ Belle Data and $E^ E^- \to B \bar{b}$ BaBar Data

None
Date: June 10, 2013
Creator: Ali, Ahmed
Object Type: Article
System: The UNT Digital Library
Measuring Sparticles with the Matrix Element (open access)

Measuring Sparticles with the Matrix Element

We apply the Matrix Element Method (MEM) to mass determination of squark pair production with direct decay to quarks and LSP at the LHC, showing that simultaneous mass determination of squarks and LSP is possible. We furthermore propose methods for inclusion of QCD radiation effects in the MEM. The goal of the LHC at CERN, scheduled to start this year, is to discover new physics through deviations from the Standard Model (SM) predictions. After discovery of deviations from the SM, the next step will be classification of the new physics. An important first goal in this process will be establishing a mass spectrum of the new particles. One of the most challenging scenarios is pair-production of new particles which decay to invisible massive particles, giving missing energy signals. Many methods have been proposed for mass determination in such scenarios (for a recent list of references, see e.g. [1]). In this proceeding, we report the first steps in applying the Matrix Element Method (MEM) in the context of supersymmetric scenarios giving missing energy signals. After a quick review of the MEM, we will focus on squark pair production, a process where other mass determination techniques have difficulties to simultaneously determine the …
Date: April 10, 2012
Creator: Alwall, Johan; /SLAC /Taiwan, Natl. Taiwan U.; Freitas, Ayres; U., /Pittsburgh; Mattelaer, Olivier & /INFN, Rome3 /Rome III U. /Louvain U.
Object Type: Article
System: The UNT Digital Library
QCD Radiation in the Production of Heavy Colored Particles at the LHC (open access)

QCD Radiation in the Production of Heavy Colored Particles at the LHC

None
Date: July 10, 2013
Creator: Alwall, Johan; de Visscher, Simon & Maltoni, Fabio
Object Type: Article
System: The UNT Digital Library
Stauts of the Laser Inertial Fusion Energy (LIFE) Hohlraum Point Design (open access)

Stauts of the Laser Inertial Fusion Energy (LIFE) Hohlraum Point Design

Progress on the hohlraum point design for the LIFE engine is described. New features in the original design [Amendt et al., Fus. Sci. Technol. 60, 49 (2011)] are incorporated that address the imperatives of low target cost, high manufacturing throughput, efficient and prompt material recycling, an ability for near-term testing of key target design uncertainties on the National Ignition Facility, and robustness to target chamber environment and injection insults. To this end, the novel use of Pb hohlraums and aerogel-supported liquid DT fuel loading within a high-density-carbon (HDC) ablator is implemented in the hohlraum point design.
Date: April 10, 2012
Creator: Amendt, P.; Dunne, M.; Ho, D.; Lasinski, B.; Meeker, D. & Ross, J. S.
Object Type: Article
System: The UNT Digital Library
The SM and NLO Multileg Working Group: Summary Report (open access)

The SM and NLO Multileg Working Group: Summary Report

After years of waiting, and after six Les Houches workshops, the era of LHC running is finally upon us, albeit at a lower initial center-of-mass energy than originally planned. Thus, there has been a great sense of anticipation from both the experimental and theoretical communities. The last two years, in particular, have seen great productivity in the area of multi-parton calculations at leading order (LO), next-to-leading order (NLO) and next-to-next-to-leading order (NNLO), and this productivity is reflected in the proceedings of the NLM group. Both religions, Feynmanians and Unitarians, as well as agnostic experimenters, were well-represented in both the discussions at Les Houches, and in the contributions to the write-up. Next-to-leading order (NLO) is the first order at which the normalization, and in some cases the shape, of perturbative cross sections can be considered reliable. This can be especially true when probing extreme kinematic regions, as for example with boosted Higgs searches considered in several of the contributions to this writeup. A full understanding for both standard model and beyond the standard model physics at the LHC requires the development of fast, reliable programs for the calculation of multi-parton final states at NLO. There have been many advances in the …
Date: April 10, 2012
Creator: Andersen, J. R.; Archibald, J.; Badger, S.; Ball, R. D.; Bevilacqua, G.; Bierenbaum, I. et al.
Object Type: Article
System: The UNT Digital Library
Search for Solar Axion Emission from 7Li and D(p,gamma)3He Nuclear Decays with the CAST gamma-ray Calorimeter (open access)

Search for Solar Axion Emission from 7Li and D(p,gamma)3He Nuclear Decays with the CAST gamma-ray Calorimeter

None
Date: July 10, 2013
Creator: Andriamonje, S.; Aune, S.; Autiero, D.; Barth, K.; Belov, A.; Beltran, B. et al.
Object Type: Article
System: The UNT Digital Library
Muon Fluence Measurements for Homeland Security Applications (open access)

Muon Fluence Measurements for Homeland Security Applications

This report focuses on work conducted at Pacific Northwest National Laboratory to better characterize aspects of backgrounds in RPMs deployed for homeland security purposes. Two polyvinyl toluene scintillators were utilized with supporting NIM electronics to measure the muon coincidence rate. Muon spallation is one mechanism by which background neutrons are produced. The measurements performed concentrated on a broad investigation of the dependence of the muon flux on a) variations in solid angle subtended by the detector; b) the detector inclination with the horizontal; c) depth underground; and d) diurnal effects. These tests were conducted inside at Building 318/133, outdoors at Building 331G, and underground at Building 3425 at Pacific Northwest National Laboratory.
Date: August 10, 2010
Creator: Ankney, Austin S.; Berguson, Timothy J.; Borgardt, James D. & Kouzes, Richard T.
Object Type: Report
System: The UNT Digital Library
6D cooling in periodic lattices including a planar snake (open access)

6D cooling in periodic lattices including a planar snake

N/A
Date: June 10, 2013
Creator: B., Palmer R.; Berg, J. S. & Stratakis, D,
Object Type: Article
System: The UNT Digital Library
An Initial Evaluation Of Characterization And Closure Options For Underground Pipelines Within A Hanford Site Single-Shell Tank Farm (open access)

An Initial Evaluation Of Characterization And Closure Options For Underground Pipelines Within A Hanford Site Single-Shell Tank Farm

The Hanford Site includes 149 single-shell tanks, organized in 12 'tank farms,' with contents managed as high-level mixed waste. The Hanford Federal Facility Agreement and Consent Order requires that one tank farm, the Waste Management Area C, be closed by June 30, 2019. A challenge to this project is the disposition and closure of Waste Management Area C underground pipelines. Waste Management Area C contains nearly seven miles of pipelines and 200 separate pipe segments. The pipelines were taken out of service decades ago and contain unknown volumes and concentrations of tank waste residuals from past operations. To understand the scope of activities that may be required for these pipelines, an evaluation was performed. The purpose of the evaluation was to identify what, if any, characterization methods and/or closure actions may be implemented at Waste Management Area C for closure of Waste Management Area C by 2019. Physical and analytical data do not exist for Waste Management Area C pipeline waste residuals. To develop estimates of residual volumes and inventories of contamination, an extensive search of available information on pipelines was conducted. The search included evaluating historical operation and occurrence records, physical attributes, schematics and drawings, and contaminant inventories associated …
Date: January 10, 2013
Creator: Badden, Janet W.; Connelly, Michael P.; Seeley, Paul N. & Hendrickson, Michelle L.
Object Type: Article
System: The UNT Digital Library
Mechanical Design of a High Energy Beam Absorber for the Advanced Superconducting Test Accelerator (ASTA) at Fermilab (open access)

Mechanical Design of a High Energy Beam Absorber for the Advanced Superconducting Test Accelerator (ASTA) at Fermilab

A high energy beam absorber has been built for the Advanced Superconducting Test Accelerator (ASTA) at Fermilab. In the facility's initial configuration, an electron beam will be accelerated through 3 TTF-type or ILC-type SRF cryomodules to an energy of 750MeV. The electron beam will be directed to one of multiple downstream experimental and diagnostic beam lines and then deposited in one of two beam absorbers. The facility is designed to accommodate up to 6 cryomodules, which would produce a 75kW beam at 1.5GeV; this is the driving design condition for the beam absorbers. The beam absorbers consist of water-cooled graphite, aluminum and copper layers contained in a helium-filled enclosure. This paper describes the mechanical implementation of the beam absorbers, with a focus on thermal design and analysis. The potential for radiation-induced degradation of the graphite is discussed.
Date: May 10, 2012
Creator: Baffes, C.; Church, M.; Leibfritz, J.; Oplt, S. & Rakhno, I.
Object Type: Article
System: The UNT Digital Library
Proceedings of RIKEN BNL Research Center Workshop: The Physics of p(up arrow)+A Collisions at RHIC (open access)

Proceedings of RIKEN BNL Research Center Workshop: The Physics of p(up arrow)+A Collisions at RHIC

N/A
Date: January 10, 2013
Creator: Bai, M.; Goto, Y.; Heppelmann, S.; Jiang, X.; Liu, M.; Makdisi, Y. et al.
Object Type: Report
System: The UNT Digital Library
INDEPENDENT CONFIRMATORY SURVEY REPORT FOR THE REACTOR BUILDING, HOT LABORATORY, PRIMARY PUMP HOUSE, AND LAND AREAS AT THE PLUM BROOK REACTOR FACILITY, SANDUSKY, OHIO (open access)

INDEPENDENT CONFIRMATORY SURVEY REPORT FOR THE REACTOR BUILDING, HOT LABORATORY, PRIMARY PUMP HOUSE, AND LAND AREAS AT THE PLUM BROOK REACTOR FACILITY, SANDUSKY, OHIO

In 1941, the War Department acquired approximately 9,000 acres of land near Sandusky, Ohio and constructed a munitions plant. The Plum Brook Ordnance Works Plant produced munitions, such as TNT, until the end of World War II. Following the war, the land remained idle until the National Advisory Committee for Aeronautics later called the National Aeronautics and Space Administration (NASA) obtained 500 acres to construct a nuclear research reactor designed to study the effects of radiation on materials used in space flight. The research reactor was put into operation in 1961 and was the first of fifteen test facilities eventually built by NASA at the Plum Brook Station. By 1963, NASA had acquired the remaining land at Plum Brook for these additional test facilities
Date: October 10, 2011
Creator: Bailey, Erika N.
Object Type: Report
System: The UNT Digital Library
Simulation of free-electron lasers seeded with broadband radiation (open access)

Simulation of free-electron lasers seeded with broadband radiation

The longitudinal coherence of free-electron laser (FEL) radiation can be enhanced by seeding the FEL with high harmonics of an optical laser pulse. The radiation produced by high-harmonic generation (HHG), however, has a fast-varying temporal profile that can violate the slowly varying envelope approximation and limited frequency window that is employed in conventional free-electron laser simulation codes. Here we investigate the implications of violating this approximation on the accuracy of simulations. On the basis of both analytical considerations and 1D numerical studies, it is concluded that, for most realistic scenarios, conventional FEL codes are capable of accurately simulating the FEL process even when the seed radiation violates the slowly varying envelope approximation. We additionally discuss the significance of filtering the harmonic content of broadband HHG seeds.
Date: March 10, 2011
Creator: Bajlekov, Svetoslav; Fawley, William; Schroeder, Carl; Bartolini, Riccardo & Hooker, Simon
Object Type: Article
System: The UNT Digital Library
Multigrid Smoothers for Ultra-Parallel Computing (open access)

Multigrid Smoothers for Ultra-Parallel Computing

None
Date: March 10, 2011
Creator: Baker, A H; Falgout, R D; Kolev, T V & Yang, U M
Object Type: Article
System: The UNT Digital Library
Lepton Universality, |V(Us)| and Search for Second Class Current in Tau Decays (open access)

Lepton Universality, |V(Us)| and Search for Second Class Current in Tau Decays

Several hundred million {tau} decays have been studied with the BABAR detector at the PEP-II e{sup +}e{sup -} collider at the SLAC National Accelerator Laboratory. Recent results on Charged Current Lepton Universality and two independent measurements of |V{sub us}| using {tau}{sup -} {yields} e{sup -}{bar {nu}}{sub e}{nu}{sub {tau}}, {mu}{sup -}{bar {nu}}{sub {mu}}{nu}{sub {tau}}, {pi}{sup -}{nu}{sub {tau}}, K{sup -} {nu}{sub {tau}} and K{sub S}{sup 0}{pi}{sup -} {nu}{sub {tau}} decays, and a search for Second Class Current in {tau}{sup -} {yields} {pi}{sup -} {omega}{nu}{sub {tau}} decays are presented, where the charge conjugate decay modes are also implied.
Date: November 10, 2011
Creator: Banerjee, Swagato
Object Type: Article
System: The UNT Digital Library
Leptonic B Decays at BaBar (open access)

Leptonic B Decays at BaBar

We will present the most recent results on leptonic B decays B{sup {+-}(0)} {yields} K*{sup {+-}(0)}{nu}{bar {nu}} and B{sup {+-}} {yields} {mu}{sup {+-}}{nu}, based on the data collected by the BaBar detector at PEP-II, an asymmetric e{sup +}e{sup -} collider at the center of mass energy of the {Upsilon}(4S) resonance. Rare B decays have always been a standard probe for New Physics (NP) searches. The very low Standard Model (SM) rate of these decays often make them unaccessible with the present experimental datasets, unless NP effects enhance the rate up to the current experimental sensitivity. Moreover, as NP effects can modify the decay kinematic, particular attention must be paid in order to perform a model independent analysis. A B-Factory provides an unique environment to investigate these processes. The high number of B{bar B} pairs produced by a B-Factory often allows to approach the needed experimental sensitivity. Moreover, the clean environment and the closed kinematic of the initial state enable to obtaining a very pure sample where to look for these decays.
Date: November 10, 2011
Creator: Baracchini, Elisabetta
Object Type: Article
System: The UNT Digital Library
Overview of the Facility Safeguardability Analysis (FSA) Process (open access)

Overview of the Facility Safeguardability Analysis (FSA) Process

The safeguards system of the International Atomic Energy Agency (IAEA) provides the international community with credible assurance that a State is fulfilling its nonproliferation obligations. The IAEA draws such conclusions from the evaluation of all available information. Effective and cost-efficient IAEA safeguards at the facility level are, and will remain, an important element of this “State-level” approach. Efficiently used, the Safeguards by Design (SBD) methodologies , , , now being developed can contribute to effective and cost-efficient facility-level safeguards. The Facility Safeguardability Assessment (FSA) introduced here supports SBD in three areas. 1. It describes necessary interactions between the IAEA, the State regulator, and the owner / designer of a new or modified facility to determine where SBD efforts can be productively applied, 2. It presents a screening approach intended to identify potential safeguard issues for; a) design changes to existing facilities; b) new facilities similar to existing facilities with approved safeguards approaches, and c) new designs, 3. It identifies resources (the FSA toolkit), such as good practice guides, design guidance, and safeguardability evaluation methods that can be used by the owner/designer to develop solutions for potential safeguards issues during the interactions with the State regulator and IAEA. FSA presents a …
Date: October 10, 2011
Creator: Bari, Robert A.; Hockert, John; Wonder, Edward F.; Johnson, Shirley J.; Wigeland, Roald & Zentner, Michael D.
Object Type: Report
System: The UNT Digital Library
On the effect of x-ray irradiation on the deformation and fracture behavior of human cortical bone (open access)

On the effect of x-ray irradiation on the deformation and fracture behavior of human cortical bone

In situ mechanical testing coupled with imaging using high-energy synchrotron x-ray diffraction or tomography imaging is gaining in popularity as a technique to investigate micrometer and even sub-micrometer deformation and fracture mechanisms in mineralized tissues, such as bone and teeth. However, the role of the irradiation in affecting the nature and properties of the tissue is not always taken into account. Accordingly, we examine here the effect of x-ray synchrotron-source irradiation on the mechanistic aspects of deformation and fracture in human cortical bone. Specifically, the strength, ductility and fracture resistance (both work-of-fracture and resistance-curve fracture toughness) of human femoral bone in the transverse (breaking) orientation were evaluated following exposures to 0.05, 70, 210 and 630 kGy irradiation. Our results show that the radiation typically used in tomography imaging can have a major and deleterious impact on the strength, post-yield behavior and fracture toughness of cortical bone, with the severity of the effect progressively increasing with higher doses of radiation. Plasticity was essentially suppressed after as little as 70 kGy of radiation; the fracture toughness was decreased by a factor of five after 210 kGy of radiation. Mechanistically, the irradiation was found to alter the salient toughening mechanisms, manifest by the …
Date: January 10, 2010
Creator: Barth, Holly D.; Launey, Maximilien E.; McDowell, Alastair A.; Ager, Joel W., III & Ritchie, Robert O.
Object Type: Article
System: The UNT Digital Library
A NMR-Based Carbon-Type Analysis of Diesel Fuel Blends From Various Sources (open access)

A NMR-Based Carbon-Type Analysis of Diesel Fuel Blends From Various Sources

In collaboration with participants of the Coordinating Research Council (CRC) Advanced Vehicle/Fuels/Lubricants (AVFL) Committee, and project AVFL-19, the characteristics of fuels from advanced and renewable sources were compared to commercial diesel fuels. The main objective of this study was to highlight similarities and differences among the fuel types, i.e. ULSD, renewables, and alternative fuels, and among fuels within the different fuel types. This report summarizes the carbon-type analysis from 1H and 13C{1H} nuclear magnetic resonance spectroscopy (NMR) of 14 diesel fuel samples. The diesel fuel samples come from diverse sources and include four commercial ultra-low sulfur diesel fuels (ULSD), one gas-to-liquid diesel fuel (GTL), six renewable diesel fuels (RD), two shale oil-derived diesel fuels, and one oil sands-derived diesel fuel. Overall, the fuels examined fall into two groups. The two shale oil-derived samples and the oil-sand-derived sample closely resemble the four commercial ultra-low sulfur diesels, with SO1 and SO2 most closely matched with ULSD1, ULSD2, and ULSD4, and OS1 most closely matched with ULSD3. As might be expected, the renewable diesel fuels, with the exception of RD3, do not resemble the ULSD fuels because of their very low aromatic content, but more closely resemble the gas-to-liquid sample (GTL) in this …
Date: May 10, 2013
Creator: Bays, J. Timothy & King, David L.
Object Type: Report
System: The UNT Digital Library
Exploring the Outer Solar System with the ESSENCE Supernova Survey (open access)

Exploring the Outer Solar System with the ESSENCE Supernova Survey

We report the discovery and orbital determination of 14 trans-Neptunian objects (TNOs) from the ESSENCE Supernova Survey difference imaging data set. Two additional objects discovered in a similar search of the SDSS-II Supernova Survey database were recovered in this effort. ESSENCE repeatedly observed fields far from the solar system ecliptic (-21{sup o} < {beta} < -5{sup o}), reaching limiting magnitudes per observation of I {approx} 23.1 and R {approx} 23.7. We examine several of the newly detected objects in detail, including 2003 UC{sub 414}, which orbits entirely between Uranus and Neptune and lies very close to a dynamical region that would make it stable for the lifetime of the solar system. 2003 SS{sub 422} and 2007 TA{sub 418} have high eccentricities and large perihelia, making them candidate members of an outer class of TNOs. We also report a new member of the 'extended' or 'detached' scattered disk, 2004 VN{sub 112}, and verify the stability of its orbit using numerical simulations. This object would have been visible to ESSENCE for only {approx}2% of its orbit, suggesting a vast number of similar objects across the sky. We emphasize that off-ecliptic surveys are optimal for uncovering the diversity of such objects, which in …
Date: November 10, 2011
Creator: Becker, A. C.; Arraki, K.; Kaib, N. A.; Wood-Vasey, W. M.; Aguilera, C.; Blackman, J. W. et al.
Object Type: Article
System: The UNT Digital Library