Phoebus: Network Middleware for Next-Generation Network Computing (open access)

Phoebus: Network Middleware for Next-Generation Network Computing

The Phoebus project investigated algorithms, protocols, and middleware infrastructure to improve end-to-end performance in high speed, dynamic networks. The Phoebus system essentially serves as an adaptation point for networks with disparate capabilities or provisioning. This adaptation can take a variety of forms including acting as a provisioning agent across multiple signaling domains, providing transport protocol adaptation points, and mapping between distributed resource reservation paradigms and the optical network control plane. We have successfully developed the system and demonstrated benefits. The Phoebus system was deployed in Internet2 and in ESnet, as well as in GEANT2, RNP in Brazil and over international links to Korea and Japan. Phoebus is a system that implements a new protocol and associated forwarding infrastructure for improving throughput in high-speed dynamic networks. It was developed to serve the needs of large DOE applications on high-performance networks. The idea underlying the Phoebus model is to embed Phoebus Gateways (PGs) in the network as on-ramps to dynamic circuit networks. The gateways act as protocol translators that allow legacy applications to use dedicated paths with high performance.
Date: June 16, 2012
Creator: Swany, Martin
Object Type: Report
System: The UNT Digital Library
CHARACTERIZATION OF TANK 16H ANNULUS SAMPLES (open access)

CHARACTERIZATION OF TANK 16H ANNULUS SAMPLES

The closure of Tank 16H will require removal of material from the annulus of the tank. Samples from Tank 16H annulus were characterized and tested to provide information to evaluate various alternatives for removing the annulus waste. The analysis found all four annulus samples to be composed mainly of Si, Na, and Al and lesser amounts of other elements. The XRD data indicate quartz (SiO{sub 2}) and sodium aluminum nitrate silicate hydrate (Na{sub 8}(Al{sub 6}Si{sub 6}O{sub 24})(NO{sub 3}){sub 2}.4H{sub 2}O) as the predominant crystalline mineral phases in the samples. The XRD data also indicate the presence of crystalline sodium nitrate, sodium nitrite, gibbsite, hydrated sodium bicarbonate, and muscovite. Based on the weight of solids remaining at the end of the test, the water leaching test results indicate approximately 20-35% of the solids dissolved after three contacts with an approximately 3:1 volume of water at 45 C. The chemical analysis of the leachates and the XRD results of the remaining solids indicate sodium salts of nitrate, nitrite, sulfate, and possibly carbonate/bicarbonate make up the majority of the dissolved material. The majority of these salts were dissolved in the first water contact and simply diluted with each subsequent water contact. The water …
Date: April 16, 2012
Creator: Hay, M. & Reboul, S.
Object Type: Report
System: The UNT Digital Library
AdS/QCD, Light-Front Holography, and Sublimated Gluons (open access)

AdS/QCD, Light-Front Holography, and Sublimated Gluons

The gauge/gravity duality leads to a simple analytical and phenomenologically compelling nonperturbative approximation to the full light-front QCD Hamiltonian - 'Light-Front Holography', which provides a Lorentz-invariant first-approximation to QCD, and successfully describes the spectroscopy of light-quark meson and baryons, their elastic and transition form factors, and other hadronic properties. The bound-state Schroedinger and Dirac equations of the soft-wall AdS/QCD model predict linear Regge trajectories which have the same slope in orbital angular momentum L and radial quantum number n for both mesons and baryons. Light-front holography connects the fifth-dimensional coordinate of AdS space z to an invariant impact separation variable {zeta} in 3+1 space at fixed light-front time. A key feature is the determination of the frame-independent light-front wavefunctions of hadrons - the relativistic analogs of the Schroedinger wavefunctions of atomic physics which allow one to compute form factors, transversity distributions, spin properties of the valence quarks, jet hadronization, and other hadronic observables. One thus obtains a one-parameter color-confining model for hadron physics at the amplitude level. AdS/QCD also predicts the form of the non-perturbative effective coupling {alpha}{sub s}{sup AdS} (Q) and its {beta}-function with an infrared fixed point which agrees with the effective coupling a{sub g1} (Q{sup 2}) extracted …
Date: February 16, 2012
Creator: Brodsky, Stanley J. & de Teramond, Guy F.
Object Type: Article
System: The UNT Digital Library
INDEPENDENT VERIFICATION SURVEY REPORT FOR ZONE 1 OF THE EAST TENNESSEE TECHNOLOGY PARK IN OAK RIDGE, TENNESSEE (open access)

INDEPENDENT VERIFICATION SURVEY REPORT FOR ZONE 1 OF THE EAST TENNESSEE TECHNOLOGY PARK IN OAK RIDGE, TENNESSEE

Oak Ridge Associated Universities (ORAU) conducted in-process inspections and independent verification (IV) surveys in support of DOE's remedial efforts in Zone 1 of East Tennessee Technology Park (ETTP) in Oak Ridge, Tennessee. Inspections concluded that the remediation contractor's soil removal and survey objectives were satisfied and the dynamic verification strategy (DVS) was implemented as designed. Independent verification (IV) activities included gamma walkover surveys and soil sample collection/analysis over multiple exposure units (EUs).
Date: August 16, 2012
Creator: King, David A.
Object Type: Report
System: The UNT Digital Library
CALIBRATION OF X-RAY IMAGING DEVICES FOR ACCURATE INTENSITY MEASUREMENT (open access)

CALIBRATION OF X-RAY IMAGING DEVICES FOR ACCURATE INTENSITY MEASUREMENT

National Security Technologies (NSTec) has developed calibration procedures for X-ray imaging systems. The X-ray sources that are used for calibration are both diode type and diode/fluorescer combinations. Calibrating the X-ray detectors is key to accurate calibration of the X-ray sources. Both energy dispersive detectors and photodiodes measuring total flux were used. We have developed calibration techniques for the detectors using radioactive sources that are traceable to the National Institute of Standards and Technology (NIST). The German synchrotron at Physikalische Technische Bundestalt (PTB) is used to calibrate silicon photodiodes over the energy range from 50 eV to 60 keV. The measurements on X-ray cameras made using the NSTec X-ray sources have included quantum efficiency averaged over all pixels, camera counts per photon per pixel, and response variation across the sensor. The instrumentation required to accomplish the calibrations is described. X-ray energies ranged from 720 eV to 22.7 keV. The X-ray sources produce narrow energy bands, allowing us to determine the properties as a function of X-ray energy. The calibrations were done for several types of imaging devices. There were back illuminated and front illuminated CCD (charge coupled device) sensors, and a CID (charge injection device) type camera. The CCD and CID …
Date: February 16, 2012
Creator: Haugh, M. J.; Charest, M. R.; Ross, P. W.; Lee, J. J.; Schneider, M. B.; Palmer, N. E. et al.
Object Type: Article
System: The UNT Digital Library
Visualization of Target Inspection data at the National Ignition Facility (open access)

Visualization of Target Inspection data at the National Ignition Facility

As the National Ignition Facility continues its campaign to achieve ignition, new methods and tools will be required to measure the quality of the target capsules used to achieve this goal. Techniques have been developed to measure capsule surface features using a phase-shifting diffraction interferometer and Leica Microsystems confocal microscope. These instruments produce multi-gigabyte datasets which consist of tens to hundreds of files. Existing software can handle viewing a small subset of an entire dataset, but none can view a dataset in its entirety. Additionally, without an established mode of transport that keeps the target capsules properly aligned throughout the assembly process, a means of aligning the two dataset coordinate systems is needed. The goal of this project is to develop web based software utilizing WebGL which will provide high level overview visualization of an entire dataset, with the capability to retrieve finer details on demand, in addition to facilitating alignment of multiple datasets with one another based on common features that have been visually identified by users of the system.
Date: February 16, 2012
Creator: Potter, D & Antipa, N
Object Type: Article
System: The UNT Digital Library
Transversity from First Principles in QCD (open access)

Transversity from First Principles in QCD

Transversity observables, such as the T-odd Sivers single-spin asymmetry measured in deep inelastic lepton scattering on polarized protons and the distributions which are measured in deeply virtual Compton scattering, provide important constraints on the fundamental quark and gluon structure of the proton. In this talk I discuss the challenge of computing these observables from first principles; i.e.; quantum chromodynamics, itself. A key step is the determination of the frame-independent light-front wavefunctions (LFWFs) of hadrons - the QCD eigensolutions which are analogs of the Schroedinger wavefunctions of atomic physics. The lensing effects of initial-state and final-state interactions, acting on LFWFs with different orbital angular momentum, lead to T-odd transversity observables such as the Sivers, Collins, and Boer-Mulders distributions. The lensing effect also leads to leading-twist phenomena which break leading-twist factorization such as the breakdown of the Lam-Tung relation in Drell-Yan reactions. A similar rescattering mechanism also leads to diffractive deep inelastic scattering, as well as nuclear shadowing and non-universal antishadowing. It is thus important to distinguish 'static' structure functions, the probability distributions computed the target hadron's light-front wavefunctions, versus 'dynamical' structure functions which include the effects of initial- and final-state rescattering. I also discuss related effects such as the J = …
Date: February 16, 2012
Creator: Brodsky, Stanley J. & /SLAC /Southern Denmark U., CP3-Origins
Object Type: Article
System: The UNT Digital Library
Dry Deposition Velocity Estimation for the Savannah River Site: Part 1 – Parametric Analysis (open access)

Dry Deposition Velocity Estimation for the Savannah River Site: Part 1 – Parametric Analysis

Values for the dry deposition velocity of airborne particles were estimated with the GENII Version 2.10 computer code for the Savannah River site using assumptions about surface roughness parameters and particle size and density. Use of the GENII code is recommended by the U.S. Department of Energy for this purpose. Meteorological conditions evaluated include atmospheric stability classes D, E, and F and wind speeds of 0.5, 1.0, 1.5, and 3.0 m/s. Local surface roughness values ranging from 0.03 to 2 meters were evaluated. Particles with mass mean diameters of 1, 5, and 10 microns and densities of 1, 3, and 5 g/cm3 were evaluated.
Date: January 16, 2012
Creator: Napier, Bruce A.
Object Type: Report
System: The UNT Digital Library
PDC IC WELD FAILURE EVALUATION AND RESOLUTION (open access)

PDC IC WELD FAILURE EVALUATION AND RESOLUTION

During final preparations for start of the PDCF Inner Can (IC) qualification effort, welding was performed on an automated weld system known as the PICN. During the initial weld, using a pedigree canister and plug, a weld defect was observed. The defect resulted in a hole in the sidewall of the canister, and it was observed that the plug sidewall had not been consumed. This was a new type of failure not seen during development and production of legacy Bagless Transfer Cans (FB-Line/Hanford). Therefore, a team was assembled to determine the root cause and to determine if the process could be improved. After several brain storming sessions (MS and T, R and D Engineering, PDC Project), an evaluation matrix was established to direct this effort. The matrix identified numerous activities that could be taken and then prioritized those activities. This effort was limited by both time and resources (the number of canisters and plugs available for testing was limited). A discovery process was initiated to evaluate the Vendor's IC fabrication process relative to legacy processes. There were no significant findings, however, some information regarding forging/anneal processes could not be obtained. Evaluations were conducted to compare mechanical properties of the PDC …
Date: April 16, 2012
Creator: Korinko, P.; Howard, S.; Maxwell, D. & Fiscus, J.
Object Type: Report
System: The UNT Digital Library
Concept of Operations for Nuclear Warhead Embedded Sensors (open access)

Concept of Operations for Nuclear Warhead Embedded Sensors

Embedded arms-control-sensors provide a powerful new paradigm for managing compliance with future nuclear weapons treaties, where deployed warhead numbers will be reduced to 1000 or less. The CONOPS (Concept of Operations) for use with these sensors is a practical tool with which one may help define design parameters, including size, power, resolution, communications, and physical structure. How frequently must data be acquired and must a human be present? Will such data be acquired for only stored weapons or will it be required of deployed weapons as well? Will tactical weapons be subject to such monitoring or will only strategic weapons apply? Which data will be most crucial? Will OSI's be a component of embedded sensor data management or will these sensors stand alone in their data extraction processes? The problem space is massive, but can be constrained by extrapolating to a reasonable future treaty regime and examining the bounded options this scenario poses. Arms control verification sensors, embedded within the warhead case or aeroshell, must provide sufficient but not excessively detailed data, confirming that the item is a nuclear warhead and that it is a particular warhead without revealing sensitive information. Geolocation will be provided by an intermediate transceiver used …
Date: May 16, 2012
Creator: Rockett, P. D. & Koncher, T. R.
Object Type: Report
System: The UNT Digital Library
Virtual tool mark generation for efficient striation analysis in forensic science (open access)

Virtual tool mark generation for efficient striation analysis in forensic science

In 2009, a National Academy of Sciences report called for investigation into the scienti#12;c basis behind tool mark comparisons (National Academy of Sciences, 2009). Answering this call, Chumbley et al. (2010) attempted to prove or disprove the hypothesis that tool marks are unique to a single tool. They developed a statistical algorithm that could, in most cases, discern matching and non-matching tool marks made at di#11;erent angles by sequentially numbered screwdriver tips. Moreover, in the cases where the algorithm misinterpreted a pair of marks, an experienced forensics examiner could discern the correct outcome. While this research served to con#12;rm the basic assumptions behind tool mark analysis, it also suggested that statistical analysis software could help to reduce the examiner's workload. This led to a new tool mark analysis approach, introduced in this thesis, that relies on 3D scans of screwdriver tip and marked plate surfaces at the micrometer scale from an optical microscope. These scans are carefully cleaned to remove noise from the data acquisition process and assigned a coordinate system that mathematically de#12;nes angles and twists in a natural way. The marking process is then simulated by using a 3D graphics software package to impart rotations to the tip …
Date: November 16, 2012
Creator: Ekstrand, Laura
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Puget Sound Tidal Energy In-Water Testing and Development Project Final Technical Report (open access)

Puget Sound Tidal Energy In-Water Testing and Development Project Final Technical Report

Tidal energy represents potential for the generation of renewable, emission free, environmentally benign, and cost effective energy from tidal flows. A successful tidal energy demonstration project in Puget Sound, Washington may enable significant commercial development resulting in important benefits for the northwest region and the nation. This project promoted the United States Department of Energy’s Wind and Hydropower Technologies Program’s goals of advancing the commercial viability, cost-competitiveness, and market acceptance of marine hydrokinetic systems. The objective of the Puget Sound Tidal Energy Demonstration Project is to conduct in-water testing and evaluation of tidal energy technology as a first step toward potential construction of a commercial-scale tidal energy power plant. The specific goal of the project phase covered by this award was to conduct all activities necessary to complete engineering design and obtain construction approvals for a pilot demonstration plant in the Admiralty Inlet region of the Puget Sound. Public Utility District No. 1 of Snohomish County (The District) accomplished the objectives of this award through four tasks: Detailed Admiralty Inlet Site Studies, Plant Design and Construction Planning, Environmental and Regulatory Activities, and Management and Reporting. Pre-Installation studies completed under this award provided invaluable data used for site selection, environmental evaluation …
Date: November 16, 2012
Creator: Collar, Craig W.
Object Type: Report
System: The UNT Digital Library
Using the X-FEL to understand X-ray Thomson scattering for partially ionized plasmas (open access)

Using the X-FEL to understand X-ray Thomson scattering for partially ionized plasmas

None
Date: July 16, 2012
Creator: Nilsen, J; Johnson, W R & Cheng, K T
Object Type: Article
System: The UNT Digital Library
Applying Alpha-Channeling to Mirror Machines (open access)

Applying Alpha-Channeling to Mirror Machines

The α-channeling effect entails the use of radio-frequency waves to expel and cool high-energetic α- particles born in a fusion reactor; the device reactivity can then be increased even further by redirecting the extracted energy to fuel ions. Originally proposed for tokamaks, this technique has also been shown to benefi t open-ended fusion devices. Here, the fundamental theory and practical aspects of α- channeling in mirror machines are reviewed, including the influence of magnetic field inhomogeneity and the effect of a finite wave region on the α-channeling mechanism. For practical implementation of the α -channeling effect in mirror geometry, suitable contained weakly-damped modes are identifi ed. In addition, the parameter space of candidate waves for implementing the α -channeling effect can be signi cantly extended through the introduction of a suitable minority ion species that has the catalytic effect of moderating the transfer of power from the α-channeling wave to the fuel ions.
Date: March 16, 2012
Creator: Zhmoginov, A. I. & Fisch, N. J.
Object Type: Report
System: The UNT Digital Library
Measuring UCG cavity development with InSAR (open access)

Measuring UCG cavity development with InSAR

None
Date: October 16, 2012
Creator: White, J & Mellors, R J
Object Type: Report
System: The UNT Digital Library
Scale Setting Using the Extended Re normalization Group and the Principle of Maximal Conformality: the QCD Coupling at Four Loops (open access)

Scale Setting Using the Extended Re normalization Group and the Principle of Maximal Conformality: the QCD Coupling at Four Loops

A key problem in making precise perturbative QCD predictions is to set the proper renormalization scale of the running coupling. The extended renormalization group equations, which express the invariance of physical observables under both the renormalization scale- and scheme-parameter transformations, provide a convenient way for estimating the scale- and scheme-dependence of the physical process. In this paper, we present a solution for the scale-equation of the extended renormalization group equations at the four-loop level. Using the principle of maximum conformality (PMC)/Brodsky-Lepage-Mackenzie (BLM) scale-setting method, all non-conformal {beta}{sub i} terms in the perturbative expansion series can be summed into the running coupling, and the resulting scale-fixed predictions are independent of the renormalization scheme. Different schemes lead to different effective PMC/BLM scales, but the final results are scheme independent. Conversely, from the requirement of scheme independence, one not only can obtain scheme-independent commensurate scale relations among different observables, but also determine the scale displacements among the PMC/BLM scales which are derived under different schemes. In principle, the PMC/BLM scales can be fixed order-by-order, and as a useful reference, we present a systematic and scheme-independent procedure for setting PMC/BLM scales up to NNLO. An explicit application for determining the scale setting of R{sub …
Date: February 16, 2012
Creator: Brodsky, Stanley J. & Wu, Xing-Gang
Object Type: Article
System: The UNT Digital Library
Vibration Model Validation for Linear Collider Detector Platforms (open access)

Vibration Model Validation for Linear Collider Detector Platforms

The ILC and CLIC reference designs incorporate reinforced-concrete platforms underneath the detectors so that the two detectors can each be moved onto and off of the beamline in a Push-Pull configuration. These platforms could potentially amplify ground vibrations, which would reduce luminosity. In this paper we compare vibration models to experimental data on reinforced concrete structures, estimate the impact on luminosity, and summarize implications for the design of a reinforced concrete platform for the ILC or CLIC detectors.
Date: May 16, 2012
Creator: Bertsche, Kirk; Amann, J. W.; Markiewicz, T. W.; Oriunno, M.; Weidemann, A. & White, G.
Object Type: Article
System: The UNT Digital Library
Physics Opportunities of a Fixed-Target Experiment using the LHC Beams (open access)

Physics Opportunities of a Fixed-Target Experiment using the LHC Beams

We outline the many physics opportunities offered by a multi-purpose fixed-target experiment using the proton and lead-ion beams of the LHC extracted by a bent crystal. In a proton run with the LHC 7-TeV beam, one can analyze pp, pd and pA collisions at center-of-mass energy {radical}s{sub NN} {approx_equal} 115 GeV and even higher using the Fermi motion of the nucleons in a nuclear target. In a lead run with a 2.76 TeV-per-nucleon beam, {radical}s{sub NN} is as high as 72 GeV. Bent crystals can be used to extract about 5 x 10{sup 8} protons/sec; the integrated luminosity over a year reaches 0.5 fb{sup -1} on a typical 1 cm-long target without nuclear species limitation. We emphasize that such an extraction mode does not alter the performance of the collider experiments at the LHC. By instrumenting the target-rapidity region, gluon and heavy-quark distributions of the proton and the neutron can be accessed at large x and even at x larger than unity in the nuclear case. Single diffractive physics and, for the first time, the large negative-xF domain can be accessed. The nuclear target-species versatility provides a unique opportunity to study nuclear matter versus the features of the hot and …
Date: March 16, 2012
Creator: Brodsky, S.J.; /SLAC; Fleuret, F.; Polytechnique, /Ecole; Hadjidakis, C.; Lansberg, J.P. et al.
Object Type: Article
System: The UNT Digital Library
ADDENDUM TO THE SURVEY REPORT FOR THE CHARACTERIZATION OF THE FIVE TANKS LOCATED NEAR THE OLD SALVAGE YARD AT THE Y-12 NATIONAL SECURITY COMPLEX, OAK RIDGE, TENNESSEE (open access)

ADDENDUM TO THE SURVEY REPORT FOR THE CHARACTERIZATION OF THE FIVE TANKS LOCATED NEAR THE OLD SALVAGE YARD AT THE Y-12 NATIONAL SECURITY COMPLEX, OAK RIDGE, TENNESSEE

The purpose if this addendum is to provide clarifying information related to two issues delaying disposal of Tank 2, located west of the Old Salvage Yard at the Y-12 National Security Complex. The two issues are as follows: 1. The discovery and documentation of apparent elevated results on the external rusty surface of Tank 2; 2. The proper interpretation and use of scan data. Oak Ridge Associated Universities (ORAU) health physics technicians (HPTs), operating under the Oak Ridge Institute for Science and Education contract, performed 100% scans over accessible interior and exterior surfaces of the five tanks located near the Old Salvage Yard, per the stakeholder-approved project-specific plan. Three types of measurements were collected, including gamma radiation measurements using a Ludlum model 44-10 gamma scintillation detector connected to a Ludlum model 2221 ratemeter/scaler; alpha radiation measurements using a Ludlum model 43-68 gas proportional detector connected to a 2221 ratemeter/scaler; and alpha-plus-beta radiation measurements also using a Ludlum model 43-68 connected to a 2221 ratermeter/scaler. The alpha-plus-beta characterization data is the primary subject of this addendum.
Date: December 16, 2012
Creator: Rollow, Kathy
Object Type: Report
System: The UNT Digital Library
Financial Analysis of Experimental Releases Conducted at Glen Canyon Dam During Water Year 2011 (open access)

Financial Analysis of Experimental Releases Conducted at Glen Canyon Dam During Water Year 2011

This report examines the financial implications of experimental flows conducted at the Glen Canyon Dam (GCD) in water year 2011. It is the third report in a series examining financial implications of experimental flows conducted since the Record of Decision (ROD) was adopted in February 1997 (Reclamation 1996). A report released in January 2011 examined water years 1997 to 2005 (Veselka et al. 2011), and a report released in August 2011 examined water years 2006 to 2010 (Poch et al. 2011). An experimental release may have either a positive or negative impact on the financial value of energy production. This study estimates the financial costs of experimental releases, identifies the main factors that contribute to these costs, and compares the interdependencies among these factors. An integrated set of tools was used to compute the financial impacts of the experimental releases by simulating the operation of the GCD under two scenarios, namely, (1) a baseline scenario that assumes both that operations comply with the ROD operating criteria and the experimental releases that actually took place during the study period, and (2) a 'without experiments' scenario that is identical to the baseline scenario of operations that comply with the GCD ROD, except …
Date: July 16, 2012
Creator: Poch, L. A.; Veselka, T. D.; Palmer, C. S.; Loftin, S.; Osiek, B. (Decision and Information Sciences) & Administration), (Western Area Power
Object Type: Report
System: The UNT Digital Library
A Non-Invasive Energy/Angle Diagnostic for Charged Particle Beams (open access)

A Non-Invasive Energy/Angle Diagnostic for Charged Particle Beams

A diagnostic for charged particle beams based on Compton scattering is presented. The particular case of an electron beam is treated in detail relativistically.
Date: March 16, 2012
Creator: Christensen, C. R.
Object Type: Article
System: The UNT Digital Library
Corrosion Performance of Advanced Structural Materials in Sodium. (open access)

Corrosion Performance of Advanced Structural Materials in Sodium.

This report gives a description of the activities in design, fabrication, construction, and assembling of a pumped sodium loop for the sodium compatibility studies on advanced structural materials. The work is the Argonne National Laboratory (ANL) portion of the effort on the work project entitled, 'Sodium Compatibility of Advanced Fast Reactor Materials,' and is a part of Advanced Materials Development within the Reactor Campaign. The objective of this project is to develop information on sodium corrosion compatibility of advanced materials being considered for sodium reactor applications. This report gives the status of the sodium pumped loop at Argonne National Laboratory, the specimen details, and the technical approach to evaluate the sodium compatibility of advanced structural alloys. This report is a deliverable from ANL in FY2010 (M2GAN10SF050302) under the work package G-AN10SF0503 'Sodium Compatibility of Advanced Fast Reactor Materials.' Two reports were issued in 2009 (Natesan and Meimei Li 2009, Natesan et al. 2009) which examined the thermodynamic and kinetic factors involved in the purity of liquid sodium coolant for sodium reactor applications as well as the design specifications for the ANL pumped loop for testing advanced structural materials. Available information was presented on solubility of several metallic and nonmetallic elements …
Date: May 16, 2012
Creator: Natesan, K.; Momozaki, Y.; Li, M. & Rink, D.L. (Nuclear Engineering Division)
Object Type: Report
System: The UNT Digital Library
Analytic Coleman-de Luccia Geometries (open access)

Analytic Coleman-de Luccia Geometries

We present the necessary and sufficient conditions for a Euclidean scale factor to be a solution of the Coleman-de Luccia equations for some analytic potential V ({psi}), with a Lorentzian continuation describing the growth of a bubble of lower-energy vacuum surrounded by higher-energy vacuum. We then give a set of explicit examples that satisfy the conditions and thus are closed-form analytic examples of Coleman-de Luccia geometries.
Date: February 16, 2012
Creator: Dong, Xi; /Stanford U., ITP /Stanford U., Phys. Dept. /SLAC; Harlow, Daniel & /Stanford U., ITP /Stanford U., Phys. Dept.
Object Type: Article
System: The UNT Digital Library
The Luminosity Function of Fermi-detected Flat-Spectrum Radio Quasars (open access)

The Luminosity Function of Fermi-detected Flat-Spectrum Radio Quasars

Fermi has provided the largest sample of {gamma}-ray selected blazars to date. In this work we use a complete sample of FSRQs detected during the first year of operation to determine the luminosity function (LF) and its evolution with cosmic time. The number density of FSRQs grows dramatically up to redshift {approx}0.5-2.0 and declines thereafter. The redshift of the peak in the density is luminosity dependent, with more luminous sources peaking at earlier times; thus the LF of {gamma}-ray FSRQs follows a luminosity-dependent density evolution similarly to that of radio-quiet AGN. Also using data from the Swift Burst Alert Telescope we derive the average spectral energy distribution of FSRQs in the 10 keV-100GeV band and show that there is no correlation of the peak {gamma}-ray luminosity with {gamma}-ray peak frequency. The coupling of the SED and LF allows us to predict that the contribution of FSRQs to the Fermi isotropic {gamma}-ray background is 9.3{sub -1.0}{sup +1.6}% ({+-}3% systematic uncertainty) in the 0.1-100GeV band. Finally we determine the LF of unbeamed FSRQs, finding that FSRQs have an average Lorentz factor of {gamma} = 11.7{sub -2.2}{sup +3.3}, that most are seen within 5{sup o} of the jet axis, and that they represent …
Date: April 16, 2012
Creator: Ajello, M.; Shaw, M. S.; Romani, R. W.; Dermer, C. D.; Costamante, L.; King, O. G. et al.
Object Type: Article
System: The UNT Digital Library