Detection of Hohlraum Target Position for Laser Fusion Experiments (open access)

Detection of Hohlraum Target Position for Laser Fusion Experiments

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Date: July 6, 2010
Creator: Awwal, A. A.
Object Type: Article
System: The UNT Digital Library
Image Processing and Control of a Programmable Spatial Light Modulator for Optic Damage Protection (open access)

Image Processing and Control of a Programmable Spatial Light Modulator for Optic Damage Protection

The heart of the National Ignition Facility is a megajoule-class laser system consisting of 192 beams used to drive inertial confinement fusion reactions. A recently installed system of programmable, liquid-crystal-based spatial light modulators adds the capability of arbitrarily shaping the spatial beam profiles in order to enhance operational flexibility. Its primary intended use is for introducing 'blocker' obscurations shadowing isolated flaws on downstream optical elements that would otherwise be damaged by high fluence laser illumination. Because an improperly shaped blocker pattern can lead to equipment damage, both the position and shape of the obscurations must be carefully verified prior to high-fluence operations. An automatic alignment algorithm is used to perform detection and estimation of the imposed blocker centroid positions compared to their intended locations. Furthermore, in order to minimize the spatially-varying nonlinear response of the device, a calibration of the local magnification is performed at multiple sub-image locations. In this paper, we describe the control and associated image processing of this device that helps to enhance the safety and longevity of the overall system.
Date: December 6, 2010
Creator: Awwal, A.; Leach, R.; Brunton, G.; Tse, E.; Matone, J. & Heebner, J.
Object Type: Article
System: The UNT Digital Library
TANK 40 FINAL SB5 CHEMICAL CHARACTERIZATION RESULTS PRIOR TO NP ADDITION (open access)

TANK 40 FINAL SB5 CHEMICAL CHARACTERIZATION RESULTS PRIOR TO NP ADDITION

A sample of Sludge Batch 5 (SB5) was pulled from Tank 40 in order to obtain radionuclide inventory analyses necessary for compliance with the Waste Acceptance Product Specifications (WAPS). This sample was also analyzed for chemical composition including noble metals. Prior to radionuclide inventory analyses, a final sample of the H-canyon Np stream will be added to bound the Np addition anticipated for Tank 40. These analyses along with the WAPS radionuclide analyses will help define the composition of the sludge in Tank 40 that is currently being fed to DWPF as SB5. At the Savannah River National Laboratory (SRNL) the 3-L Tank 40 SB5 sample was transferred from the shipping container into a 4-L high density polyethylene vessel and solids allowed to settle overnight. Supernate was then siphoned off and circulated through the shipping container to complete the transfer of the sample. Following thorough mixing of the 3-L sample, a 239 g sub-sample was removed. This sub-sample was then utilized for all subsequent analytical samples. Eight separate aliquots of the slurry were digested, four with HNO{sub 3}/HCl (aqua regia) in sealed Teflon{reg_sign} vessels and four in Na{sub 2}O{sub 2} (alkali or peroxide fusion) using Zr crucibles. Due to the …
Date: January 6, 2010
Creator: Bannochie, C. & Click, D.
Object Type: Report
System: The UNT Digital Library
Nondestructive depth-resolved spectroscopic investigation of the heavily intermixed In2S3/Cu(In,Ga)Se2 interface (open access)

Nondestructive depth-resolved spectroscopic investigation of the heavily intermixed In2S3/Cu(In,Ga)Se2 interface

The chemical structure of the interface between a nominal In2S3 buffer and a Cu(In,Ga)Se2 (CIGSe) thin-film solar cell absorber was investigated by soft x-ray photoelectron and emission spectroscopy. We find a heavily intermixed, complex interface structure, in which Cu diffuses into (and Na through) the buffer layer, while the CIGSe absorber surface/interface region is partially sulfurized. Based on our spectroscopic analysis, a comprehensive picture of the chemical interface structure is proposed.
Date: April 6, 2010
Creator: Bar, Marcus; Barreau, N.; Couzinie-Devy, F.; Pookpanratana, S.; Klaer, J.; Blum, M. et al.
Object Type: Article
System: The UNT Digital Library
Dynamical Layer Decoupling in a Stripe-ordered, High T_c Superconductor (open access)

Dynamical Layer Decoupling in a Stripe-ordered, High T_c Superconductor

In the stripe-ordered state of a strongly-correlated two-dimensional electronic system, under a set of special circumstances, the superconducting condensate, like the magnetic order, can occur at a non-zero wave-vector corresponding to a spatial period double that of the charge order. In this case, the Josephson coupling between near neighbor planes, especially in a crystal with the special structure of La{sub 2-x}Ba{sub x}CuO{sub 4}, vanishes identically. We propose that this is the underlying cause of the dynamical decoupling of the layers recently observed in transport measurements at x = 1/8.
Date: April 6, 2010
Creator: Berg, E.
Object Type: Article
System: The UNT Digital Library
Self-consistent solution for proximity effect and Josephson current in ballistic graphene SNS Josephson junctions (open access)

Self-consistent solution for proximity effect and Josephson current in ballistic graphene SNS Josephson junctions

We use a tight-binding Bogoliubov-de Gennes (BdG) formalism to self-consistently calculate the proximity effect, Josephson current, and local density of states in ballistic graphene SNS Josephson junctions. Both short and long junctions, with respect to the superconducting coherence length, are considered, as well as different doping levels of the graphene. We show that self-consistency does not notably change the current-phase relationship derived earlier for short junctions using the non-selfconsistent Dirac-BdG formalism but predict a significantly increased critical current with a stronger junction length dependence. In addition, we show that in junctions with no Fermi level mismatch between the N and S regions superconductivity persists even in the longest junctions we can investigate, indicating a diverging Ginzburg-Landau superconducting coherence length in the normal region.
Date: April 6, 2010
Creator: Black-Schaffer, Annica M.
Object Type: Article
System: The UNT Digital Library
Layed Perovskite PRBA0.5SR0.5CO205 as High Performance Cathode for Solid Oxide Fuels Using Photon Conducting Electrolyte (open access)

Layed Perovskite PRBA0.5SR0.5CO205 as High Performance Cathode for Solid Oxide Fuels Using Photon Conducting Electrolyte

This paper discusses solid oxide fuel cells, proton conductors, layered perovskite and Cathodes.
Date: May 6, 2010
Creator: Brinkman, K.
Object Type: Article
System: The UNT Digital Library
The Stability and Electrical Properties of High Temperature Proton Conductors (open access)

The Stability and Electrical Properties of High Temperature Proton Conductors

The morphological and electrical properties of Ba{sub 1-x}Sr{sub x}Ce{sub 0.8}Y{sub 0.2}O{sub 3-{delta}} with x varying from 0 to 1 prepared by a modified Pechini method were investigated as potential high temperature proton conductors. Dense microstructures were achieved for all the samples upon sintering at 1500 C for 5 h. The phase structure analysis indicated that perovskite phase was formed for 0 {le} x {le} 0.2, while for x larger than 0.5, impurity phases of Sr{sub 2}CeO{sub 4} and Y{sub 2}O{sub 3} appeared. The tolerance to H{sub 2}O for the samples improved with the increase in Sr content when exposed to boiling water, while the electrical conductivity decreased from x = 0 to 1. However, the resistance to CO{sub 2} attack at elevated temperatures was not improved within the whole x range studied.
Date: July 6, 2010
Creator: Brinkman, K.
Object Type: Article
System: The UNT Digital Library
Development of Sensors and Sensing Technology for Hydrogen Fuel Cell Vehicle Applications (open access)

Development of Sensors and Sensing Technology for Hydrogen Fuel Cell Vehicle Applications

One related area of hydrogen fuel cell vehicle (FCV) development that cannot be overlooked is the anticipated requirement for new sensors for both the monitoring and control of the fuel cell's systems and for those devices that will be required for safety. Present day automobiles have dozens of sensors on-board including those for IC engine management/control, sensors for state-of-health monitoring/control of emissions systems, sensors for control of active safety systems, sensors for triggering passive safety systems, and sensors for more mundane tasks such as fluids level monitoring to name the more obvious. The number of sensors continues to grow every few years as a result of safety mandates but also in response to consumer demands for new conveniences and safety features. Some of these devices (e.g. yaw sensors for dynamic stability control systems or tire presure warning RF-based devices) may be used on fuel cell vehicles without any modification. However the use of hydrogen as a fuel will dictate the development of completely new technologies for such requirements as the detection of hydrogen leaks, sensors and systems to continuously monitor hydrogen fuel purity and protect the fuel cell stack from poisoning, and for the important, yet often taken for granted, …
Date: January 6, 2010
Creator: Brosha, E. L.; Sekhar, P. K.; Mukundan, R.; Williamson, T.; Garzon, F. H.; Woo, L. Y. et al.
Object Type: Article
System: The UNT Digital Library
Benefits and Costs of Aggressive Energy Efficiency Programs and the Impacts of Alternative Sources of Funding: Case Study of Massachusetts (open access)

Benefits and Costs of Aggressive Energy Efficiency Programs and the Impacts of Alternative Sources of Funding: Case Study of Massachusetts

Increased interest by state (and federal) policymakers and regulatory agencies in pursuing aggressive energy efficiency efforts could deliver significant utility bill savings for customers while having long-term implications for ratepayers (e.g. potential rate impacts). Equity and distributional concerns associated with the authorized recovery of energy efficiency program costs may necessitate the pursuit of alternative program funding approaches. In 2008, Massachusetts passed the Green Communities Act which directed its energy efficiency (EE) program administrators to obtain all cost-effective EE resources. This goal has translated into achieving annual electric energy savings equivalent to a 2.4% reduction in retail sales from energy efficiency programs in 2012. Representatives of electricity consumer groups supported the new portfolio of EE programs (and the projected bill savings) but raised concerns about the potential rate impacts associated with achieving such aggressive EE goals, leading policymakers to seek out alternative funding sources which can potentially mitigate these effects. Utility administrators have also raised concerns about under-recovery of fixed costs when aggressive energy efficiency programs are pursued and have proposed ratemaking policies (e.g. decoupling) and business models that better align the utility's financial interests with the state's energy efficiency public policy goals. Quantifying these concerns and identifying ways they can …
Date: August 6, 2010
Creator: Cappers, Peter; Satchwell, Andrew; Goldman, Charles & Schlegel, Jeff
Object Type: Report
System: The UNT Digital Library
Erratum: Time-step Considerations in Particle Simulation Algorithms for Coulomb Collisions in Plasmas [B.I. Cohen, A. M. Dimits, A. Friedman, and R. E. Caflisch, IEEE Trans. Plasma Sci. 38, 2394 (2010)] (open access)

Erratum: Time-step Considerations in Particle Simulation Algorithms for Coulomb Collisions in Plasmas [B.I. Cohen, A. M. Dimits, A. Friedman, and R. E. Caflisch, IEEE Trans. Plasma Sci. 38, 2394 (2010)]

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Date: October 6, 2010
Creator: Cohen, B. I.; Dimits, A. M.; Friedman, A. & Caflisch, R.
Object Type: Article
System: The UNT Digital Library
Reaching Grid Parity Using BP Solar Crystalline Silicon Technology: A Systems Class Application (open access)

Reaching Grid Parity Using BP Solar Crystalline Silicon Technology: A Systems Class Application

The primary target market for this program was the residential and commercial PV markets, drawing on BP Solar's premium product and service offerings, brand and marketing strength, and unique routes to market. These two markets were chosen because: (1) in 2005 they represented more than 50% of the overall US PV market; (2) they are the two markets that will likely meet grid parity first; and (3) they are the two market segments in which product development can lead to the added value necessary to generate market growth before reaching grid parity. Federal investment in this program resulted in substantial progress toward the DOE TPP target, providing significant advancements in the following areas: (1) Lower component costs particularly the modules and inverters. (2) Increased availability and lower cost of silicon feedstock. (3) Product specifically developed for residential and commercial applications. (4) Reducing the cost of installation through optimization of the products. (5) Increased value of electricity in mid-term to drive volume increases, via the green grid technology. (6) Large scale manufacture of PV products in the US, generating increased US employment in manufacturing and installation. To achieve these goals BP Solar assembled a team that included suppliers of critical materials, …
Date: December 6, 2010
Creator: Cunningham, Daniel W.; Wohlgemuth, John; Carlson, David E.; Clark, Roger F.; Gleaton, Mark; Posbic, John P. et al.
Object Type: Report
System: The UNT Digital Library
Performance Analysis: Control of Hazardous Energy (open access)

Performance Analysis: Control of Hazardous Energy

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Date: October 6, 2010
Creator: De Grange, C E; Freeman, J W & Kerr, C E
Object Type: Report
System: The UNT Digital Library
The dynamical core, physical parameterizations, and basic simulation characteristics of the atmospheric component of the GFDL global coupled model CM3 (open access)

The dynamical core, physical parameterizations, and basic simulation characteristics of the atmospheric component of the GFDL global coupled model CM3

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Date: July 6, 2010
Creator: Donner, L. J.; Wyman, B. L.; Hemler, R. S.; Horowitz, L. W.; Ming, Y.; Zhao, M. et al.
Object Type: Article
System: The UNT Digital Library
MARS Flight Engineering Status (open access)

MARS Flight Engineering Status

The Multi-sensor Airborne Radiation Survey Flight Engineering project (MARS FE) has designed a high purity germanium (HPGe) crystal array for conducting a wide range of field measurements. In addition to the HPGe detector system, a platform-specific shock and vibration isolation system and environmental housing have been designed to support demonstration activities in a maritime environment on an Unmanned Surface Vehicle (USV). This report describes the status of the equipment as of the end of FY09.
Date: April 6, 2010
Creator: Fast, James E.; Dorow, Kevin E.; Morris, Scott J.; Thompson, Robert C. & Willett, Jesse A.
Object Type: Report
System: The UNT Digital Library
The Need for a Strong Science and Technology Program in the Nuclear Weapons Complex for the 21st Century (open access)

The Need for a Strong Science and Technology Program in the Nuclear Weapons Complex for the 21st Century

In this paper I argue for the need for a strong Science and Technology program in the Nuclear Weapons Complex as the basis for maintaining a credible deterrence capability. The current Nuclear Posture Review establishes a New Triad as the basis for the United States deterrence strategy in a changing security environment. A predictive science capability is at the core of a credible National Nuclear Weapons program in the 21st Century. In absence of nuclear testing, the certification of our current Nuclear Weapons relies on predictive simulations and quantification of the associated simulation uncertainties. In addition, a robust nuclear infrastructure needs an active research and development program that considers all the required nuclear scenarios, including new configurations for which there is no nuclear test data. This paper also considers alternative positions to the need for a Science and Technology program in the Nuclear Weapons complex.
Date: January 6, 2010
Creator: Garaizar, X
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Aircraft Cabin Environmental Quality Sensors (open access)

Aircraft Cabin Environmental Quality Sensors

The Indoor Environment Department at Lawrence Berkeley National Laboratory (LBNL) teamed with seven universities to participate in a Federal Aviation Administration (FAA) Center of Excellence (COE) for research on environmental quality in aircraft. This report describes research performed at LBNL on selecting and evaluating sensors for monitoring environmental quality in aircraft cabins, as part of Project 7 of the FAA's COE for Airliner Cabin Environmental Research (ACER)1 effort. This part of Project 7 links to the ozone, pesticide, and incident projects for data collection and monitoring and is a component of a broader research effort on sensors by ACER. Results from UCB and LBNL's concurrent research on ozone (ACER Project 1) are found in Weschler et al., 2007; Bhangar et al. 2008; Coleman et al., 2008 and Strom-Tejsen et al., 2008. LBNL's research on pesticides (ACER Project 2) in airliner cabins is described in Maddalena and McKone (2008). This report focused on the sensors needed for normal contaminants and conditions in aircraft. The results are intended to complement and coordinate with results from other ACER members who concentrated primarily on (a) sensors for chemical and biological pollutants that might be released intentionally in aircraft; (b) integration of sensor systems; and …
Date: May 6, 2010
Creator: Gundel, Lara; Kirchstetter, Thomas; Spears, Michael & Sullivan, Douglas
Object Type: Report
System: The UNT Digital Library
Sources and transport systems for low energy extreme of ion implantation (open access)

Sources and transport systems for low energy extreme of ion implantation

For the past seven years a joint research and development effort focusing on the design of steady state, intense ion sources has been in progress with the ultimate goal being to meet the two, energy extreme range needs of mega-electron-volt and 100's of electron-volt ion implanters. However, since the last Fortier is low energy ion implantation, focus of the endeavor has shifted to low energy ion implantation. For boron cluster source development, we started with molecular ions of decaborane (B{sub 10}H{sub 14}), octadecaborane (B{sub 18}H{sub 22}), and presently our focus is on carborane (C{sub 2}B{sub 10}H{sub 12}) ions developing methods for mitigating graphite deposition. Simultaneously, we are developing a pure boron ion source (without a working gas) that can form the basis for a novel, more efficient, plasma immersion source. Our Calutron-Berna ion source was converted into a universal source capable of switching between generating molecular phosphorous P{sub 4}{sup +}, high charge state ions, as well as other types of ions. Additionally, we have developed transport systems capable of transporting a very large variety of ion species, and simulations of a novel gasless/plasmaless ion beam deceleration method were also performed.
Date: June 6, 2010
Creator: Hershcovitch, A.; Batalin, V. A.; Bugaev, A. S.; Gushenets, V. I.; Alexeyenko, O.; Gurkova, E. et al.
Object Type: Article
System: The UNT Digital Library
Comparing GPU Implementations of Bilateral and Anisotropic Diffusion Filters for 3D Biomedical Datasets (open access)

Comparing GPU Implementations of Bilateral and Anisotropic Diffusion Filters for 3D Biomedical Datasets

We compare the performance of hand-tuned CUDA implementations of bilateral and anisotropic diffusion filters for denoising 3D MRI datasets. Our tests sweep comparable parameters for the two filters and measure total runtime, memory bandwidth, computational throughput, and mean squared errors relative to a noiseless reference dataset.
Date: May 6, 2010
Creator: Howison, Mark
Object Type: Report
System: The UNT Digital Library
Structure of Oxide Nanoparticles in Fe-16Cr MA/ODS Ferritic Steel (open access)

Structure of Oxide Nanoparticles in Fe-16Cr MA/ODS Ferritic Steel

Oxide nanoparticles in Fe-16Cr ODS ferritic steel fabricated by mechanical alloying (MA) method have been examined using high-resolution transmission electron microscopy (HRTEM) techniques. A partial crystallization of oxide nanoparticles was frequently observed in as-fabricated ODS steel. The crystal structure of crystalline oxide particles is identified to be mainly Y{sub 4}Al{sub 2}O{sub 9} (YAM) with a monoclinic structure. Large nanoparticles with a diameter larger than 20 nm tend to be incoherent and have a nearly spherical shape, whereas small nanoparticles with a diameter smaller than 10 nm tend to be coherent or semi-coherent and have faceted boundaries. The oxide nanoparticles become fully crystallized after prolonged annealing at 900 C. These results lead us to propose a three-stage formation mechanism of oxide nanoparticles in MA/ODS steels.
Date: April 6, 2010
Creator: Hsiung, L; Fluss, M & Kimura, A
Object Type: Article
System: The UNT Digital Library
LAND AND WATER USE CHARACTERISTICS AND HUMAN HEALTH INPUT PARAMETERS FOR USE IN ENVIRONMENTAL DOSIMETRY AND RISK ASSESSMENTS AT THE SAVANNAH RIVER SITE (open access)

LAND AND WATER USE CHARACTERISTICS AND HUMAN HEALTH INPUT PARAMETERS FOR USE IN ENVIRONMENTAL DOSIMETRY AND RISK ASSESSMENTS AT THE SAVANNAH RIVER SITE

Operations at the Savannah River Site (SRS) result in releases of small amounts of radioactive materials to the atmosphere and to the Savannah River. For regulatory compliance purposes, potential offsite radiological doses are estimated annually using computer models that follow U.S. Nuclear Regulatory Commission (NRC) Regulatory Guides. Within the regulatory guides, default values are provided for many of the dose model parameters but the use of site-specific values by the applicant is encouraged. A detailed survey of land and water use parameters was conducted in 1991 and is being updated here. These parameters include local characteristics of meat, milk and vegetable production; river recreational activities; and meat, milk and vegetable consumption rates as well as other human usage parameters required in the SRS dosimetry models. In addition, the preferred elemental bioaccumulation factors and transfer factors to be used in human health exposure calculations at SRS are documented. Based on comparisons to the 2009 SRS environmental compliance doses, the following effects are expected in future SRS compliance dose calculations: (1) Aquatic all-pathway maximally exposed individual doses may go up about 10 percent due to changes in the aquatic bioaccumulation factors; (2) Aquatic all-pathway collective doses may go up about 5 percent …
Date: August 6, 2010
Creator: Jannik, T.; Karapatakis, D.; Lee, P. & Farfan, E.
Object Type: Report
System: The UNT Digital Library
Using Quasi-Monoenergetic Photon Sources to Probe Photo-Fission Resonances (open access)

Using Quasi-Monoenergetic Photon Sources to Probe Photo-Fission Resonances

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Date: August 6, 2010
Creator: Johnson, M. S.; Hall, J. M.; McNabb, D. P.; Tuffley, M.; Ahmed, M.; Stave, S. et al.
Object Type: Article
System: The UNT Digital Library
Development of Characterization Technology for Fault Zone Hydrology (open access)

Development of Characterization Technology for Fault Zone Hydrology

Several deep trenches were cut, and a number of geophysical surveys were conducted across the Wildcat Fault in the hills east of Berkeley, California. The Wildcat Fault is believed to be a strike-slip fault and a member of the Hayward Fault System, with over 10 km of displacement. So far, three boreholes of ~;; 150m deep have been core-drilled and borehole geophysical logs were conducted. The rocks are extensively sheared and fractured; gouges were observed at several depths and a thick cataclasitic zone was also observed. While confirming some earlier, published conclusions from shallow observations about Wildcat, some unexpected findings were encountered. Preliminary analysis indicates that Wildcat near the field site consists of multiple faults. The hydraulic test data suggest the dual properties of the hydrologic structure of the fault zone. A fourth borehole is planned to penetrate the main fault believed to lie in-between the holes. The main philosophy behind our approach for the hydrologic characterization of such a complex fractured system is to let the system take its own average and monitor a long term behavior instead of collecting a multitude of data at small length and time scales, or at a discrete fracture scale and to ?up-scale,? …
Date: August 6, 2010
Creator: Karasaki, Kenzi; Onishi, Tiemi; Gasperikova, Erika; Goto, Junichi; Tsuchi, Hiroyuki; Miwa, Tadashi et al.
Object Type: Article
System: The UNT Digital Library
EEMP Summary for NIF shot: N101004-002-999 (open access)

EEMP Summary for NIF shot: N101004-002-999

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Date: October 6, 2010
Creator: Kimbrough, J
Object Type: Report
System: The UNT Digital Library