Cost-Effective Silicon Wafers for Solar Cells (open access)

Cost-Effective Silicon Wafers for Solar Cells

Advanced Research Projects Agency-Energy project sheet summarizing general information about a new program for hydrogen fuel cell vehicles (project title "Direct Wafer Enabling Terawatt Photovoltaics") including critical needs, innovation and advantages, impacts, and contact information. This sheet is the first open solicitation, announcing funding opportunities for involvement in the project.
Date: May 11, 2012
Creator: 1366 Technologies, Inc.
Object Type: Text
System: The UNT Digital Library
Local Effects of Biased Electrodes in the Divertor of NSTX (open access)

Local Effects of Biased Electrodes in the Divertor of NSTX

The goal of this paper is to characterize the effects of small non-axisymmetric divertor plate electrodes on the local scrape-off layer plasma. Four small rectangular electrodes were installed into the outer divertor plates of NSTX. When the electrodes were located near the outer divertor strike point and biased positively, there was an increase in the nearby probe currents and probe potentials and an increase in the LiI light emission at the large major radius end of these electrodes. When an electrode located farther outward from the outer divertor strike point was biased positively, there was sometimes a significant decrease in the LiI light emission at the small major radius end of this electrode, but there were no clear effects on the nearby probes. No non-local effects were observed with the biasing of these electrodes.
Date: May 7, 2012
Creator: : S. Zweben, M.D. Campanell, B.C. Lyons, R.J. Maqueda, Y. Raitses, A.L. Roquemore and F. Scotti
Object Type: Report
System: The UNT Digital Library
Analysis of Vernier Scans during the PP2PP run in 2009 (pp at 100 GeV/beam) (open access)

Analysis of Vernier Scans during the PP2PP run in 2009 (pp at 100 GeV/beam)

N/A
Date: May 1, 2012
Creator: A., Drees
Object Type: Report
System: The UNT Digital Library
Shielding of a hadron in a finite e-beam (open access)

Shielding of a hadron in a finite e-beam

The thorough study of coherent electron cooling, the modern cooling technique capable to deal with accelerators operating in the range of few TeVs, rises many interesting questions. One of them is a shielding dynamics of a hadron in an electron beam. Now this effect is computed analytically in the infinite beam approximation. Many effects are drastically different in finite and infinite plasmas. Here we propose a method to compute the dynamical shielding effect in a finite cylindrical plasma - the realistic model of an electron beam in accelerators.
Date: May 20, 2012
Creator: A., Elizarov; Litvinenko, V. & Wang, G.
Object Type: Article
System: The UNT Digital Library
Towards demonstration of electron cooling with bunched electron beam (open access)

Towards demonstration of electron cooling with bunched electron beam

N/A
Date: May 1, 2012
Creator: A., Fedotov
Object Type: Report
System: The UNT Digital Library
Optics modification of the electron collector for the Relativistic Heavy Ion Collider Electron Beam Ion Source (open access)

Optics modification of the electron collector for the Relativistic Heavy Ion Collider Electron Beam Ion Source

N/A
Date: May 1, 2012
Creator: A., Pikin; Alessi, J.G.; Beebe, E.N.; Raparia, D. & Snydstrup, L.
Object Type: Report
System: The UNT Digital Library
Optics modification of the electron collector for the Relativistic Heavy Ion Collider Electron Beam Ion Source (open access)

Optics modification of the electron collector for the Relativistic Heavy Ion Collider Electron Beam Ion Source

N/A
Date: May 1, 2012
Creator: A., Pikin; Alessi, J.G.; Beebe, E.N.; Raparia, D. & Snydstrup, L.
Object Type: Report
System: The UNT Digital Library
Porosity in millimeter-scale welds of stainless steel : three-dimensional characterization. (open access)

Porosity in millimeter-scale welds of stainless steel : three-dimensional characterization.

A variety of edge joints utilizing a continuous wave Nd:YAG laser have been produced and examined in a 304-L stainless steel to advance fundamental understanding of the linkage between processing and resultant microstructure in high-rate solidification events. Acquisition of three-dimensional reconstructions via micro-computed tomography combined with traditional metallography has allowed for qualitative and quantitative characterization of weld joints in a material system of wide use and broad applicability. The presence, variability and distribution of porosity, has been examined for average values, spatial distributions and morphology and then related back to fundamental processing parameters such as weld speed, weld power and laser focal length.
Date: May 1, 2012
Creator: Aagesen, Larry K. & Madison, Jonathan D.
Object Type: Report
System: The UNT Digital Library
$W$ boson polarization measurement in the $t\bar{t}$ dilepton channel using the CDF II Detector (open access)

$W$ boson polarization measurement in the $t\bar{t}$ dilepton channel using the CDF II Detector

We present a measurement of W boson polarization in top-quark decays in t{bar t} events with decays to dilepton final states using 5.1 fb{sup -1} integrated luminosity in p{bar p} collisions collected by the CDF II detector at the Tevatron. A simultaneous measurement of the fractions of longitudinal (f{sub 0}) and right-handed (f{sub +}) W bosons yields the results f{sub 0} = 0.71{sub -0.17}{sup +0.18}(stat) {+-} 0.06(syst) and f{sub +} = -0.07 {+-} 0.09(stat) {+-} 0.03(syst). Combining this measurement with our previous result based on single lepton final states, we obtain f{sub 0} = 0.84 {+-} 0.09(stat) {+-} 0.05(syst) and f{sub +} = -0.16 {+-} 0.05(stat) {+-} 0.04(syst). The results are consistent with standard model expectation.
Date: May 1, 2012
Creator: Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A. et al.
Object Type: Article
System: The UNT Digital Library
Measurement of the Cosmic Ray e+ plus e- Spectrum from 20 GeV to 1 TeV with the Fermi Large Area Telescope (open access)

Measurement of the Cosmic Ray e+ plus e- Spectrum from 20 GeV to 1 TeV with the Fermi Large Area Telescope

Designed as a high-sensitivity gamma-ray observatory, the Fermi Large Area Telescope is also an electron detector with a large acceptance exceeding 2 m{sup 2}sr at 300 GeV. Building on the gamma-ray analysis, we have developed an efficient electron detection strategy which provides sufficient background rejection for measurement of the steeply-falling electron spectrum up to 1 TeV. Our high precision data show that the electron spectrum falls with energy as E{sup -3.0} and does not exhibit prominent spectral features. Interpretations in terms of a conventional diffusive model as well as a potential local extra component are briefly discussed.
Date: May 14, 2012
Creator: Abdo, Aous A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Ajello, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. et al.
Object Type: Article
System: The UNT Digital Library
Conversion Tower for Dispatchable Solar Power (open access)

Conversion Tower for Dispatchable Solar Power

Advanced Research Projects Agency-Energy project sheet summarizing general information about the High Energy Advanced Thermal Storage (HEATS) program including critical needs, innovation and advantages, impacts, and contact information. This sheet discusses new system architecture for a solar-electric conversion tower as part of the "High-Efficiency Solar-Electric Conversion Power Tower" project.
Date: May 25, 2012
Creator: Abengoa Solar, Inc.
Object Type: Text
System: The UNT Digital Library
A METHODOLOGY FOR DETERMINING THE DOSE RATE FOR BOUNDING MASS LIMITS IN A 9977 PACKAGING (open access)

A METHODOLOGY FOR DETERMINING THE DOSE RATE FOR BOUNDING MASS LIMITS IN A 9977 PACKAGING

The Small Gram Quantity (SGQ) concept is based on the understanding that the hazards associated with the shipment of a radioactive material are directly proportional to its mass. This study describes a methodology that estimates the acceptable masses for several neutron and gamma emitting isotopes that can be shipped in a 9977 Package compliant with the Title 10 of the Code of Federal Regulations, Part 71 (10CFR71) external radiation level limits. 10CFR71.33 states that a shipping application identifies the radioactive and fissile materials at their maximum quantity and provides an evaluation demonstrating compliance with the external radiation standards. Since rather small amounts of some isotopes emit sufficiently strong radiation to produce a large external dose rate, quantifying of the dose rate for a proposed content is a challenging issue for the SGQ approach. It is essential to quantify external radiation levels from several common gamma and neutron sources that can be safely placed in a specific packaging, to ensure compliance with federal regulations. A methodology was established for determining the dose rate for bounding mass limits for a set of isotopes in the Model 9977 Shipping Package. Calculations were performed to estimate external radiation levels using the MCNP radiation transport …
Date: May 24, 2012
Creator: Abramczyk, G.; Bellamy, S.; Nathan, S. & Loftin, B.
Object Type: Article
System: The UNT Digital Library
Fish Health Studies Associated with the Kingston Fly Ash Spill, Spring 2009 - Fall 2010 (open access)

Fish Health Studies Associated with the Kingston Fly Ash Spill, Spring 2009 - Fall 2010

On December 22, 2008, over 4 million cubic meters of fly ash slurry was released into the Emory River when a dike surrounding a solid waste containment area at the Tennessee Valley Authority's (TVA) Kingston Fossil Plant ruptured. One component of TVA's response to the spill is a biological monitoring program to assess short- and long-term ecological responses to the ash and associated chemicals, including studies on fish health and contaminant bioaccumulation. These studies were initiated in early Spring 2009 for the purposes of: (1) documenting the levels of fly ash-associated metals in various tissues of representative sentinel fish species in the area of the fly ash spill, (2) determining if exposure to fly ash-associated metals causes short, intermediate, or long-term health effects on these sentinel fish species, (3) assessing if there are causal relationships between exposure to metals and health effects on fish, (4) evaluating, along with information from other ecological and physicochemical studies, the nature and route of contaminant transfer though food chains into higher level consumers, (5) providing important information for the Ecological Risk Assessment (ERA) for the Kingston fly ash project, and (6) serving as an important technology information transfer or model study focused on how …
Date: May 1, 2012
Creator: Adams, Marshall & Fortner, Allison M
Object Type: Report
System: The UNT Digital Library
Bioaccumulation Studies Associated with the Kingston Fly Ash Spill, Spring 2009 - Fall 2010 (open access)

Bioaccumulation Studies Associated with the Kingston Fly Ash Spill, Spring 2009 - Fall 2010

In December 2008, an ash dike at the Tennessee Valley Authority (TVA) Kingston Fossil Plant ruptured, releasing over one billion gallons of coal fly ash into the Emory and Clinch Rivers. Coal fly ash may contain several contaminants of concern, but of these selenium (Se) and arsenic (As) have been highlighted because of their toxicity and tendency to bioaccumulate in aquatic food chains. To assess the potential impact of the spilled fly ash on humans and the environment, a comprehensive biological and environmental monitoring program was established, for which resident aquatic organisms (among other sample media) are collected to determine contaminant exposure and evaluate the risk to humans and wildlife. Studies on bioaccumulation and fish health are major components of the TVA Biological Monitoring Program for the Kingston fly ash project. These studies were initiated in early Spring 2009 for the purposes of: (1) documenting the levels of fly ash-associated metals in various tissues of representative sentinel fish species in the area of the fly ash spill, (2) determining if exposure to fly ash-associated metals causes short, intermediate, or long-term health effects on these sentinel fish species, (3) assessing if there are causal relationships between exposure (to metals) and effects …
Date: May 1, 2012
Creator: Adams, Marshall; Brandt, Craig C & Fortner, Allison M
Object Type: Report
System: The UNT Digital Library
METAL MEDIA FILTERS, AG-1 SECTION FI (open access)

METAL MEDIA FILTERS, AG-1 SECTION FI

One application of metal media filters is in various nuclear air cleaning processes including applications for protecting workers, the public and the environment from hazardous and radioactive particles. To support this application the development of the ASME AG-1 FI Standard on Metal Media has been under way for more than ten years. Development of the proposed section has required resolving several difficult issues associated with operating conditions (media velocity, pressure drop, etc.), qualification testing, and quality acceptance testing. Performance characteristics of metal media are dramatically different than the glass fiber media with respect to parameters like differential pressures, operating temperatures, media strength, etc. These differences make existing data for a glass fiber media inadequate for qualifying a metal media filter for AG-1. In the past much work has been conducted on metal media filters at facilities such as Lawrence Livermore National Laboratory (LLNL) and Savannah River National Laboratory (SRNL) to qualify the media as High Efficiency Particulate Air (HEPA) Filters. Particle retention testing has been conducted at Oak Ridge Filter Test Facility and at Air Techniques International (ATI) to prove that the metal media meets or exceeds the 99.97% particle retention required for a HEPA Filter. Even with his testing, …
Date: May 23, 2012
Creator: Adamson, D.
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
Engineering Enzymes in Energy Crops (open access)

Engineering Enzymes in Energy Crops

Advanced Research Projects Agency-Energy project sheet summarizing general information about a new program to engineer plants to produce enzymes that will reduce costs in the production of biofuel (project title "Conditionally Activated Enzymes Expressed in Cellulosic Energy Crops") including critical needs, innovation and advantages, impacts, and contact information. This sheet is the first open solicitation, announcing funding opportunities for involvement in the project.
Date: May 11, 2012
Creator: Agrivdia
Object Type: Text
System: The UNT Digital Library
A 3 TeV Muon Collider Lattice Design (open access)

A 3 TeV Muon Collider Lattice Design

A new lattice for 3 TeV c.o.m. energy with {beta}* = 5mm was developed which follows the basic concept of the earlier 1.5 TeV design but uses quad triplets for the final focus in order to keep the maximum magnet strength and aperture close to those in 1.5 TeV case. Another difference is employment of combined-function magnets with the goal to lower heat deposition in magnet cold mass and to eliminate bending field free regions which produce 'hot spots' of neutrino radiation that can be an issue at higher energy. The proposed lattice is shown to satisfy the requirements on luminosity, dynamic aperture and momentum acceptance.
Date: May 1, 2012
Creator: Alexahin, Y. & Gianfelice-Wendt, E.
Object Type: Article
System: The UNT Digital Library
Design of Accumulator and Compressor Rings for the Project-X Based Proton Driver (open access)

Design of Accumulator and Compressor Rings for the Project-X Based Proton Driver

A Muon Collider (MC) and a Neutrino Factory (NF) - which may be considered as a step towards a MC - both require a high-power ({approx}4 MW) proton driver providing short (<1 m r.m.s. length) bunches for muon production. However, the driver repetition rates required for these two machines are different: {approx}15 Hz for MC and {approx}60 Hz for NF. This difference suggests employing two separate rings: one for accumulation of the proton beam from the Project-X linac in a few (e.g. 4) long bunches, the other for bunch compression - one by one for NF or all at a time for MC with simultaneous delivery to the target. The lattice requirements for these two rings are different: the momentum compaction factor in the accumulator ring should be large (and possibly negative) to avoid the microwave instability, while the compressor ring can be nearly isochronous in order to limit the required RF voltage and reduce the dispersion contribution to the beam size. In the present report we consider ring lattice designs which achieve these goals.
Date: May 1, 2012
Creator: Alexahin, Y. & Neuffer, D.
Object Type: Article
System: The UNT Digital Library
Observation of Instabilities of Coherent Transverse Oscillations in the Fermilab Booster (open access)

Observation of Instabilities of Coherent Transverse Oscillations in the Fermilab Booster

The Fermilab Booster - built more than 40 years ago - operates well above the design proton beam intensity of 4 {center_dot} 10{sup 12} ppp. Still, the Fermilab neutrino experiments call for even higher intensity exceeding 5.5 {center_dot} 10{sup 12} ppp. A multitude of intensity related effects must be overcome in order to meet this goal including suppression of coherent dipole instabilities of transverse oscillations which manifest themselves as a sudden drop in the beam current. In this report we present the results of observation of these instabilities at different tune, coupling and chromaticity settings and discuss possible cures.
Date: May 1, 2012
Creator: Alexahin, Y.; Eddy, N.; Gianfelice-Wendt, E.; Lebedev, V.; Marsh, W.; Pellico, W. et al.
Object Type: Article
System: The UNT Digital Library
Effect of Field Errors in Muon Collider IR Magnets on Beam Dynamics (open access)

Effect of Field Errors in Muon Collider IR Magnets on Beam Dynamics

In order to achieve peak luminosity of a Muon Collider (MC) in the 10{sup 35} cm{sup -2}s{sup -1} range very small values of beta-function at the interaction point (IP) are necessary ({beta}* {le} 1 cm) while the distance from IP to the first quadrupole can not be made shorter than {approx}6 m as dictated by the necessity of detector protection from backgrounds. In the result the beta-function at the final focus quadrupoles can reach 100 km making beam dynamics very sensitive to all kind of errors. In the present report we consider the effects on momentum acceptance and dynamic aperture of multipole field errors in the body of IR dipoles as well as of fringe-fields in both dipoles and quadrupoles in the ase of 1.5 TeV (c.o.m.) MC. Analysis shows these effects to be strong but correctable with dedicated multipole correctors.
Date: May 1, 2012
Creator: Alexahin, Y.; Gianfelice-Wendt, E.; Kapin, V.V. & /Fermilab
Object Type: Article
System: The UNT Digital Library
Tune Determination of Strongly Coupled Betatron Oscillations in a Fast-Ramping Synchrotron (open access)

Tune Determination of Strongly Coupled Betatron Oscillations in a Fast-Ramping Synchrotron

Tune identification -- i.e. attribution of the spectral peak to a particular normal de of oscillations -- can present a significant difficulty in the presence of strong transverse coupling when the normal mode with a lower damping rate dominates spectra of Turn-by-Turn oscillations in both planes. The introduced earlier phased sum algorithm helped to recover the weaker normal mode signal from the noise, but by itself proved to be insufficient for automatic peak identification in the case of close phase advance distribution in both planes. To resolve this difficulty we modified the algorithm by taking and analyzing Turn-by-Turn data for two different ramps with the beam oscillation excited in each plane in turn. Comparison of relative amplitudes of Fourier components allows for correct automatic tune identification. The proposed algorithm was implemented in the Fermilab Booster B38 console application and successfully used for tune, coupling and chromaticity measurements.
Date: May 1, 2012
Creator: Alexahin, Y.; Gianfelice-Wendt, E.; Marsh, W & Triplett, K.
Object Type: Article
System: The UNT Digital Library
Magnets for Interaction Regions of a 1.5 x 1.5 TeV Muon Collider (open access)

Magnets for Interaction Regions of a 1.5 x 1.5 TeV Muon Collider

None
Date: May 1, 2012
Creator: Alexahin, Y.; Kashikhin, V.; Mokhov, N. V.; Zlobin, A. V. & /Fermilab
Object Type: Article
System: The UNT Digital Library
Fuel From Algae (open access)

Fuel From Algae

Advanced Research Projects Agency-Energy project sheet summarizing general information about a new program to efficiently separate micro-solids from water (project title "Scaling and Commercialization of Algae Harvesting Technologies") including critical needs, innovation and advantages, impacts, and contact information. This sheet is the first open solicitation, announcing funding opportunities for involvement in the project.
Date: May 11, 2012
Creator: Algaeventure Systems
Object Type: Text
System: The UNT Digital Library