Large Synoptic Survey Telescope: From Science Drivers to Reference Design (open access)

Large Synoptic Survey Telescope: From Science Drivers to Reference Design

In the history of astronomy, major advances in our understanding of the Universe have come from dramatic improvements in our ability to accurately measure astronomical quantities. Aided by rapid progress in information technology, current sky surveys are changing the way we view and study the Universe. Next-generation surveys will maintain this revolutionary progress. We focus here on the most ambitious survey currently planned in the visible band, the Large Synoptic Survey Telescope (LSST). LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: constraining dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. It will be a large, wide-field ground-based system designed to obtain multiple images covering the sky that is visible from Cerro Pachon in Northern Chile. The current baseline design, with an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg{sup 2} field of view, and a 3,200 Megapixel camera, will allow about 10,000 square degrees of sky to be covered using pairs of 15-second exposures in two photometric bands every three nights on average. The system is designed to yield high image …
Date: October 14, 2011
Creator: Ivezic, Z.; Axelrod, T.; Brandt, W. N.; Burke, D. L.; Claver, C. F.; Connolly, A. et al.
Object Type: Article
System: The UNT Digital Library
Studies of non-proportionality in alkali halide and strontium iodide scintillators using SLYNCI (open access)

Studies of non-proportionality in alkali halide and strontium iodide scintillators using SLYNCI

Recently a collaboration of LLNL and LBNL has constructed a second generation Compton coincidence instrument to study the non-proportionality of scintillators. This device, known as SLYNCI (Scintillator Light-Yield Non-proportionality Characterization Instrument), has can completely characterize a sample with less than 24 hours of running time. Thus, SLYNCI enables a number of systematic studies of scintillators since many samples can be processed in a reasonable length of time. These studies include differences in nonproportionality between different types of scintillators, different members of the same family of scintillators, and impact of different doping levels. The results of such recent studies are presented here, including a study of various alkali halides, and the impact of europium doping level in strontium iodide. Directions of future work area also discussed.
Date: October 14, 2010
Creator: Ahle, Larry; Bizarri, Gregory; Boatner, Lynn; Cherepy, Nerine J.; Choong, Woon-Seng; Moses, William W. et al.
Object Type: Article
System: The UNT Digital Library
Echo Enabled High Mode Generation for X-Ray FELs (open access)

Echo Enabled High Mode Generation for X-Ray FELs

None
Date: October 14, 2013
Creator: Hemsing, E.; /SLAC; Marinelli, A. & /UCLA
Object Type: Article
System: The UNT Digital Library
Determination of Gamma from B \to K*Pi Decays and Related Modes (open access)

Determination of Gamma from B \to K*Pi Decays and Related Modes

None
Date: October 14, 2013
Creator: Puccio, Eugenia Maria Teresa Irene & U., /Warwick
Object Type: Article
System: The UNT Digital Library
Exotic/charmonium Hadron Spectroscopy at Belle and BaBar (open access)

Exotic/charmonium Hadron Spectroscopy at Belle and BaBar

None
Date: October 14, 2013
Creator: Liventsev, Dmitri & /Moscow, ITEP
Object Type: Article
System: The UNT Digital Library
Pion-Photon Transition Form Factor And Pion Distribution Amplitude in QCD: Facing the Enigmatic Behavior of the BaBar Data (open access)

Pion-Photon Transition Form Factor And Pion Distribution Amplitude in QCD: Facing the Enigmatic Behavior of the BaBar Data

None
Date: October 14, 2013
Creator: Stefanis, N. G.; Bakulev, Alexander P.; Mikhailov, S. V. & Pimikov, A. V.
Object Type: Article
System: The UNT Digital Library
CORROSION TESTING OF CARBON STEEL IN OXALIC ACID CHEMICAL CLEANING SOLUTIONS (open access)

CORROSION TESTING OF CARBON STEEL IN OXALIC ACID CHEMICAL CLEANING SOLUTIONS

Radioactive liquid waste has been stored in underground carbon steel tanks for nearly 60 years at the Savannah River Site. The site is currently in the process of removing the waste from these tanks in order to place it into vitrified, stable state for longer term storage. The last stage in the removal sequence is a chemical cleaning step that breaks up and dissolves metal oxide solids that cannot be easily pumped out of the tank. Oxalic acid has been selected for this purpose because it is an effective chelating agent for the solids and is not as corrosive as other acids. Electrochemical and immersion studies were conducted to investigate the corrosion behavior of carbon steel in simulated chemical cleaning environments. The effects of temperature, agitation, and the presence of sludge solids in the oxalic acid on the corrosion rate and the likelihood of hydrogen evolution were determined. The testing showed that the corrosion rates decreased significantly in the presence of the sludge solids. Corrosion rates increased with agitation, however, the changes were less noticeable.
Date: October 14, 2011
Creator: Wiersma, B.; Mickalonis, J.; Subramanian, K. & Ketusky, E.
Object Type: Article
System: The UNT Digital Library
Radiation and Thermal Analysis of Superconducting Quadrupoles in the Interaction Region of Linear Collider (open access)

Radiation and Thermal Analysis of Superconducting Quadrupoles in the Interaction Region of Linear Collider

Radiation heat deposition in the superconducting magnets of the Interaction Region (IR) of a linear collider can be a serious issue that limits the magnet operating margins and shortens the material lifetime. Radiation and thermal analyses of the IR quadrupoles in the incoming and extraction beam lines of the ILC are performed in order to determine the magnet limits. This paper presents an analysis of the radial, azimuthal and longitudinal distributions of heat deposition in the incoming and disrupted beam doublets. Operation margins of the magnets based on NbTi superconductor are calculated and compared. The radiation and thermal analysis of the ILC IR quadrupoles based on Rutherford type cables was performed. It was found that the peak radiation heat deposition takes place in the second extraction quadrupole QFEX2. The maximum power density in the coil is {approx}17mW/g. This is rather high, comparing to the proton machines (LHC). However, the fast radial decay of the heat deposition together with the high thermal conductivity of the Rutherford type cable limits the coil temperatures to a moderate level. It was determined that both 2-layer and 4-layer QFEX2 magnet designs have thermal margins of a factor of {approx}4 at the nominal gradient of 31.3 …
Date: October 14, 2011
Creator: Drozhdin, A. I.; Kashikhin, V. V.; Kashikhin, V. S.; Lopes, M. L.; Mokhov, N. V.; Zlobin, A. V. et al.
Object Type: Article
System: The UNT Digital Library
Challenges And Concepts for Design of An Interaction Region With Push-Pull Arrangement of Detectors - An Interface Document (open access)

Challenges And Concepts for Design of An Interaction Region With Push-Pull Arrangement of Detectors - An Interface Document

Two experimental detectors working in a push-pull mode has been considered for the Interaction Region of the International Linear Collider. The push-pull mode of operation sets specific requirements and challenges for many systems of detector and machine, in particular for the IR magnets, for the cryogenics and alignment system, for beamline shielding, for detector design and overall integration, and so on. These challenges and the identified conceptual solutions discussed in the paper intend to form a draft of the Interface Document which will be developed further in the nearest future. The authors of the present paper include the organizers and conveners of working groups of the workshop on engineering design of interaction region IRENG07, the leaders of the IR Integration within Global Design Effort Beam Delivery System, and the representatives from each detector concept submitting the Letters Of Intent.
Date: October 14, 2011
Creator: Parker, B.; /Brookhaven; Herve, Alain; Osborne, J.; /CERN; Mikhailichenko, A. et al.
Object Type: Article
System: The UNT Digital Library
Generation of Multi-Color Attosecond X-Ray Radiation Through Modulation Compression (open access)

Generation of Multi-Color Attosecond X-Ray Radiation Through Modulation Compression

None
Date: October 14, 2013
Creator: Qiang, Ji; /LBL, Berkeley & Wu, Juhao
Object Type: Article
System: The UNT Digital Library
RELIABILITY BASED DESIGN OF FIXED FOUNDATION WIND TURBINES (open access)

RELIABILITY BASED DESIGN OF FIXED FOUNDATION WIND TURBINES

Recent analysis of offshore wind turbine foundations using both applicable API and IEC standards show that the total load demand from wind and waves is greatest in wave driven storms. Further, analysis of overturning moment loads (OTM) reveal that impact forces exerted by breaking waves are the largest contributor to OTM in big storms at wind speeds above the operating range of 25 m/s. Currently, no codes or standards for offshore wind power generators have been adopted by the Bureau of Ocean Energy Management Regulation and Enforcement (BOEMRE) for use on the Outer Continental Shelf (OCS). Current design methods based on allowable stress design (ASD) incorporate the uncertainty in the variation of loads transferred to the foundation and geotechnical capacity of the soil and rock to support the loads is incorporated into a factor of safety. Sources of uncertainty include spatial and temporal variation of engineering properties, reliability of property measurements applicability and sufficiency of sampling and testing methods, modeling errors, and variability of estimated load predictions. In ASD these sources of variability are generally given qualitative rather than quantitative consideration. The IEC 61400‐3 design standard for offshore wind turbines is based on ASD methods. Load and resistance factor design …
Date: October 14, 2013
Creator: Nichols, R.
Object Type: Article
System: The UNT Digital Library
Optics and Emittance Studies Using the ATF2 Multi-OTR System (open access)

Optics and Emittance Studies Using the ATF2 Multi-OTR System

None
Date: October 14, 2013
Creator: Alabau-Gonzalvo, J.; Blanch Gutierrez, C.; Faus-Golfe, A.; Garcia-Garrigos, J. J.; Resta-L?pez, J.; U., /Valencia et al.
Object Type: Article
System: The UNT Digital Library

3D Thermal and Electrochemical Model for Spirally Wound Large Format Lithium-ion Batteries

In many commercial cells, long tabs at both cell sides, leading to uniform potentials along the spiral direction of wound jelly rolls, are rarely seen because of their high manufacturing cost. More often, several metal strips are welded at discrete locations along both current collector foils. With this design, the difference of electrical potentials is easily built up along current collectors in the spiral direction. Hence, the design features of the tabs, such as number, location and size, can be crucial factors for spiral-shaped battery cells. This paper presents a Li-ion battery cell model having a 3-dimensional spiral mesh involving a wound jellyroll structure. Further results and analysis will be given regarding impacts of tab location, number, and size.
Date: October 14, 2010
Creator: Lee, K. J.; Kim, G. H. & Smith, K.
Object Type: Presentation
System: The UNT Digital Library
From Multileg Loops to Trees (by-passing Feynman's Tree Theorem) (open access)

From Multileg Loops to Trees (by-passing Feynman's Tree Theorem)

We illustrate a duality relation between one-loop integrals and single-cut phase-space integrals. The duality relation is realised by a modification of the customary +i0 prescription of the Feynman propagators. The new prescription regularizing the propagators, which we write in a Lorentz covariant form, compensates for the absence of multiple-cut contributions that appear in the Feynman Tree Theorem. The duality relation can be extended to generic one-loop quantities, such as Green's functions, in any relativistic, local and unitary field theories. The physics program of LHC requires the evaluation of multi-leg signal and background processes at next-to-leading order (NLO). In the recent years, important efforts have been devoted to the calculation of many 2 {yields} 3 processes and some 2 {yields} 4 processes. We have recently proposed a method to compute multi-leg one-loop cross sections in perturbative field theories. The method uses combined analytical and numerical techniques. The starting point of the method is a duality relation between one-loop integrals and phase-space integrals. In this respect, the duality relation has analogies with the Feynman's Tree Theorem (FTT). The key difference with the FTT is that the duality relation involves only single cuts of the one-loop Feynman diagrams. In this talk, we illustrate …
Date: October 14, 2011
Creator: Rodrigo, German; Catani, Stefano; Gleisberg, Tanju; Krauss, Frank & Winter, Jan-Christopher
Object Type: Article
System: The UNT Digital Library
B Decays and CP Violation from BaBar (open access)

B Decays and CP Violation from BaBar

None
Date: October 14, 2013
Creator: Palombo, Fernando
Object Type: Article
System: The UNT Digital Library
Measurements of the CKM Angle Gamma with BaBar (open access)

Measurements of the CKM Angle Gamma with BaBar

None
Date: October 14, 2013
Creator: Martinez-Vidal, Fernando & /Valencia U., IFIC
Object Type: Article
System: The UNT Digital Library
Final Report for DOE Grant DE-FG02-03ER25579; Development of High-Order Accurate Interface Tracking Algorithms and Improved Constitutive Models for Problems in Continuum Mechanics with Applications to Jetting (open access)

Final Report for DOE Grant DE-FG02-03ER25579; Development of High-Order Accurate Interface Tracking Algorithms and Improved Constitutive Models for Problems in Continuum Mechanics with Applications to Jetting

Much of the work conducted under the auspices of DE-FG02-03ER25579 was characterized by an exceptionally close collaboration with researchers at the Lawrence Berkeley National Laboratory (LBNL). For example, Andy Nonaka, one of Professor Miller's graduate students in the Department of Applied Science at U. C. Davis (UCD) wrote his PhD thesis in an area of interest to researchers in the Applied Numerical Algorithms Group (ANAG), which is a part of the National Energy Research Supercomputer Center (NERSC) at LBNL. Dr. Nonaka collaborated closely with these researchers and subsequently published the results of this collaboration jointly with them, one article in a peer reviewed journal article and one paper in the proceedings of a conference. Dr. Nonaka is now a research scientist in the Center for Computational Sciences and Engineering (CCSE), which is also part of the National Energy Research Supercomputer Center (NERSC) at LBNL. This collaboration with researchers at LBNL also included having one of Professor Puckett's graduate students in the Graduate Group in Applied Mathematics (GGAM) at UCD, Sarah Williams, spend the summer working with Dr. Ann Almgren, who is a staff scientist in CCSE. As a result of this visit Sarah decided work on a problem suggested by …
Date: October 14, 2012
Creator: Puckett, Elbridge Gerry & Miller, Gregory Hale
Object Type: Report
System: The UNT Digital Library
MEASUREMENT OF TRITIUM DURING VOLOXIDATION OF ZIRCALOY-2 FUEL HULLS (open access)

MEASUREMENT OF TRITIUM DURING VOLOXIDATION OF ZIRCALOY-2 FUEL HULLS

A straightforward method to evaluate the tritium content of Zircaloy-2 cladding hulls via oxidation of the hull and capture of the volatilized tritium in liquids has been demonstrated. Hull samples were heated in air inside a thermogravimetric analyzer (TGA). The TGA was rapidly heated to 1000 C to oxidize the hulls and release absorbed tritium. To capture tritium, the TGA off-gas was bubbled through a series of liquid traps. The concentrations of tritium in bubbler solutions indicated that tritiated water vapor was captured nearly quantitatively. The average tritium content measured in the hulls was 19% of the amount of tritium produced by the fuel, according to ORIGEN2 isotope generation and depletion calculations. Published experimental data show that Zircaloy-2 oxidation follows an Arrhenius model, and that an initial, nonlinear oxidation rate is followed by a faster, linear rate after 'breakaway' of the oxide film. This study demonstrates that the linear oxidation rate of Zircaloy samples at 974 C is faster than predicted by the extrapolation of data from lower temperatures.
Date: October 14, 2010
Creator: Crowder, M.; Laurinat, J. & Stillman, J.
Object Type: Article
System: The UNT Digital Library
Constructing a resilience index for the enhanced critical in Frastructure Protection Program. (open access)

Constructing a resilience index for the enhanced critical in Frastructure Protection Program.

Following recommendations made in Homeland Security Presidential Directive 7, which established a national policy for the identification and increased protection of critical infrastructure and key resources (CIKR) by Federal departments and agencies, the U.S. Department of Homeland Security (DHS) in 2006 developed the Enhanced Critical Infrastructure Protection (ECIP) program. The ECIP program aimed to provide a closer partnership with state, regional, territorial, local, and tribal authorities in fulfilling the national objective to improve CIKR protection. The program was specifically designed to identify protective measures currently in place in CIKR and to inform facility owners/operators of the benefits of new protective measures. The ECIP program also sought to enhance existing relationships between DHS and owners/operators of CIKR and to build relationships where none existed (DHS 2008; DHS 2009). In 2009, DHS and its protective security advisors (PSAs) began assessing CIKR assets using the ECIP program and ultimately produced individual protective measure and vulnerability values through the protective measure and vulnerability indices (PMI/VI). The PMI/VI assess the protective measures posture of individual facilities at their 'weakest link,' allowing for a detailed analysis of the most vulnerable aspects of the facilities (Schneier 2003), while maintaining the ability to produce an overall protective measures …
Date: October 14, 2010
Creator: Fisher, R. E.; Bassett, G. W.; Buehring, W. A.; Collins, M. J.; Dickinson, D. C.; Eaton, L. K. et al.
Object Type: Report
System: The UNT Digital Library
Final Scientific Technical Report: INTEGRATED PREDICTIVE DEMAND RESPONSE CONTROLLER FOR COMMERCIAL BUILDINGS (open access)

Final Scientific Technical Report: INTEGRATED PREDICTIVE DEMAND RESPONSE CONTROLLER FOR COMMERCIAL BUILDINGS

This project provides algorithms to perform demand response using the thermal mass of a building. Using the thermal mass of the building is an attractive method for performing demand response because there is no need for capital expenditure. The algorithms rely on the thermal capacitance inherent in the building?s construction materials. A near-optimal ?day ahead? predictive approach is developed that is meant to keep the building?s electrical demand constant during the high cost periods. This type of approach is appropriate for both time-of-use and critical peak pricing utility rate structures. The approach uses the past days data in order to determine the best temperature setpoints for the building during the high price periods on the next day. A second ?model predictive approach? (MPC) uses a thermal model of the building to determine the best temperature for the next sample period. The approach uses constant feedback from the building and is capable of appropriately handling real time pricing. Both approaches are capable of using weather forecasts to improve performance.
Date: October 14, 2013
Creator: Wenzel, Mike
Object Type: Report
System: The UNT Digital Library
Searches for Physics Beyond the Standard Model and Triggering on Proton-Proton Collisions at 14 TEV LHC (open access)

Searches for Physics Beyond the Standard Model and Triggering on Proton-Proton Collisions at 14 TEV LHC

This document describes the work achieved under the OJI award received May 2008 by Peter Wittich as Principal Investigator. The proposal covers experimental particle physics project searching for physics beyond the standard model at the Large Hadron Collider (LHC) at the European Organization for Nuclear Research.
Date: October 14, 2011
Creator: Wittich, Peter
Object Type: Report
System: The UNT Digital Library
Phase-resolved x-ray ferromagnetic resonance measurements in fluorescence yield (open access)

Phase-resolved x-ray ferromagnetic resonance measurements in fluorescence yield

Phase-resolved x-ray ferromagnetic resonance (XFMR) has been measured in fluorescence yield, extending the application of XFMR to opaque samples on opaque substrates. Magnetization dynamics were excited in a Co{sub 50}Fe{sub 50}(0.7)/Ni{sub 90}Fe{sub 10}(5) bilayer by means of a continuous wave microwave excitation, while x-ray magnetic circular dichroism (XMCD) spectra were measured stroboscopically at different points in the precession cycle. By tuning the x-ray energy to the L{sub 3} edges of Ni and Fe, the dependence of the real and imaginary components of the element specific magnetic susceptibility on the strength of an externally applied static bias field was determined. First results from measurements on a Co{sub 50}Fe{sub 50}(0.7)/Ni{sub 90}Fe{sub 10}(5)/Dy(1) sample confirm that enhanced damping results from the addition of the Dy cap.
Date: October 14, 2010
Creator: Marcham, M. K.; Keatley, P. S.; Neudert, A.; Hicken, R. J.; Cavill, S. A.; Shelford, L. R. et al.
Object Type: Article
System: The UNT Digital Library
Structural and Mechanical Effects of Radiation Exposure on Filled Elastomers - Recent Insights From Experiments and Modeling (open access)

Structural and Mechanical Effects of Radiation Exposure on Filled Elastomers - Recent Insights From Experiments and Modeling

None
Date: October 14, 2011
Creator: Maiti, A.; Weisgraber, T.; Gee, R.; Dinh, L.; Wilson, T.; Small, W. et al.
Object Type: Article
System: The UNT Digital Library
FY13 LLNL OMEGA Experimental Programs (open access)

FY13 LLNL OMEGA Experimental Programs

None
Date: October 14, 2013
Creator: Heeter, R. F.; Fournier, K. B.; Baker, K.; Brown, G. V.; Casey, D.; Celliers, P. et al.
Object Type: Report
System: The UNT Digital Library