Plasma Channel Diagnostic Based on Laser Centroid Oscillations (open access)

Plasma Channel Diagnostic Based on Laser Centroid Oscillations

A technique has been developed for measuring the properties of discharge-based plasma channels by monitoring the centroid location of a laser beam exiting the channel as a function of input alignment offset between the laser and the channel. The centroid position of low-intensity (<10{sup 14}Wcm{sup -2}) laser pulses focused at the input of a hydrogen-filled capillary discharge waveguide was scanned and the exit positions recorded to determine the channel shape and depth with an accuracy of a few %. In addition, accurate alignment of the laser beam through the plasma channel can be provided by minimizing laser centroid motion at the channel exit as the channel depth is scanned either by scanning the plasma density or the discharge timing. The improvement in alignment accuracy provided by this technique will be crucial for minimizing electron beam pointing errors in laser plasma accelerators.
Date: September 9, 2010
Creator: Gonsalves, Anthony; Nakamura, Kei; Lin, Chen; Osterhoff, Jens; Shiraishi, Satomi; Schroeder, Carl et al.
Object Type: Article
System: The UNT Digital Library
Final Assembly of Cryogenic Targets for NIF (open access)

Final Assembly of Cryogenic Targets for NIF

None
Date: February 9, 2010
Creator: Swisher, M F; Montesanti, R C; Alger, E T; Castro, C; Dzenitis, E G; Edwards, G J et al.
Object Type: Article
System: The UNT Digital Library
Time-Integrated Searches for Point-like Sources of Neutrinos with the 40-String IceCube Detector (open access)

Time-Integrated Searches for Point-like Sources of Neutrinos with the 40-String IceCube Detector

None
Date: December 9, 2010
Creator: IceCube & etal, Abbasi, R,
Object Type: Article
System: The UNT Digital Library
Solid State NMR Investigations of Chain Dynamics and Network Order in Model Poly(dimethylsiloxane) Elastomers (open access)

Solid State NMR Investigations of Chain Dynamics and Network Order in Model Poly(dimethylsiloxane) Elastomers

This work is at a relatively early stage, however it has been demonstrated that we can reliably probe basic network architectures using the MQ-NMR technique. The initial results are in good agreement with what is known from standard network theory and will serve as a basis for the study of progressively increasing structural complexity in Siloxane network systems.
Date: December 9, 2010
Creator: Lewicki, J P; Mayer, B P; Wilson, T S; Chinn, S C & Maxwell, R S
Object Type: Article
System: The UNT Digital Library

H2A Delivery Analysis and H2A Delivery Components Model

This presentation summarizes H2A Delivery Analysis and H2A Delivery Components Model.
Date: June 9, 2010
Creator: Sozinova, O.
Object Type: Presentation
System: The UNT Digital Library
Main Injector Particle Production Experiment (MIPP) at Fermilab (open access)

Main Injector Particle Production Experiment (MIPP) at Fermilab

The Main Injector Particle Production Experiment at Fermilab uses particle beams of charged pions, kaons, proton and anti-proton with beam momenta of 5 to 90 GeV/c and thin targets spanning the periodic table from (liquid) hydrogen to uranium to measure particle production cross sections in a full acceptance spectrometer with charged particle identification for particles from 0.1 to 120 GeV/c using Time Projection Chamber, Time of Flight, multicell Cherenkov, and Ring Imaging Cherenkov detectors and Calorimeter for neutrons. Particle production using 120 GeV/c protons from Main Injector on the MINOS target was also measured. We describe the physics motivation to perform such cross section measurements and highlight the impact of hadronic interaction data on neutrino physics. Recent results on forward neutron cross sections and analysis of MINOS target data are also presented.
Date: December 9, 2010
Creator: Mahajan, Sonam
Object Type: Article
System: The UNT Digital Library
Laser supported solid state absorption fronts in silica (open access)

Laser supported solid state absorption fronts in silica

We develop a model based on simulation and experiment that explains the behavior of solid-state laser-supported absorption fronts generated in fused silica during high intensity (up to 5GW/cm{sup 2}) laser exposure. We find that the absorption front velocity is constant in time and is nearly linear in laser intensity. Further, this model can explain the dependence of laser damage site size on these parameters. This behavior is driven principally by the temperature-activated deep sub band-gap optical absorptivity, free electron transport and thermal diffusion in defect-free silica for temperatures up to 15,000K and pressures < 15GPa. The regime of parameter space critical to this problem spans and extends that measured by other means. It serves as a platform for understanding general laser-matter interactions in dielectrics under a variety of conditions.
Date: February 9, 2010
Creator: Carr, C W & Bude, J D
Object Type: Article
System: The UNT Digital Library
Development of High Efficacy, Low Cost Phosphorescent Oled Lightning Luminaire (open access)

Development of High Efficacy, Low Cost Phosphorescent Oled Lightning Luminaire

In this two year program, UDC together with Armstrong World Industries, Professor Stephen Forrest (University of Michigan) and Professor Mark Thompson (University of Southern California) planned to develop and deliver high efficiency OLED lighting luminaires as part of an integrated ceiling illumination system that exceed the Department of Energy (DOE) 2010 performance projections. Specifically the UDC team in 2010 delivered two prototype OLED ceiling illumination systems, each consisting of four individual OLED lighting panels on glass integrated into Armstrong's novel TechZone open architecture ceiling systems, at an overall system efficacy of 51 lm/W, a CRI = 85 and a projected lifetime to 70% of initial luminance to exceed 10,000 hours. This accomplishment represents a 50% increase in luminaire efficacy and a factor of two in lifetime over that outlined in the solicitation. In addition, the team has also delivered one 15cm x 15cm lighting panel fabricated on a flexible metal foil substrate, demonstrating the possibility using OLEDs in a range of form factors. During this program, our Team has pursued the commercialization of these OLED based ceiling luminaires, with a goal to launch commercial products within the next three years. We have proven that our team is ideally suited to …
Date: July 9, 2010
Creator: Hack, Michael
Object Type: Report
System: The UNT Digital Library
Tethys: The Marine and Hydrokinetic Technology Environmental Impacts Knowledge Management System -- Requirements Specification -- Version 1.0 (open access)

Tethys: The Marine and Hydrokinetic Technology Environmental Impacts Knowledge Management System -- Requirements Specification -- Version 1.0

The marine and hydrokinetic (MHK) environmental impacts knowledge management system (KMS), dubbed Tethys after the mythical Greek goddess of the seas, is being developed for the U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy Wind and Hydropower Technologies Program (WHTP) by Pacific Northwest National Laboratory (PNNL). This requirements specification establishes the essential capabilities required of Tethys and clarifies for WHTP and the Tethys development team the results that must be achieved by the system.
Date: November 9, 2010
Creator: Butner, R. Scott; Snowden-Swan, Lesley J. & Ellis, Peter C.
Object Type: Report
System: The UNT Digital Library
Strongly Interacting Matter Matter at Very High Energy Density: 3 Lectures in Zakopane (open access)

Strongly Interacting Matter Matter at Very High Energy Density: 3 Lectures in Zakopane

These lectures concern the properties of strongly interacting matter at very high energy density. I begin with the Color Glass Condensate and the Glasma, matter that controls the earliest times in hadronic collisions. I then describe the Quark Gluon Plasma, matter produced from the thermalized remnants of the Glasma. Finally, I describe high density baryonic matter, in particular Quarkyonic matter. The discussion will be intuitive and based on simple structural aspects of QCD. There will be some discussion of experimental tests of these ideas.
Date: June 9, 2010
Creator: McLerran, L.
Object Type: Article
System: The UNT Digital Library

Questions Utilities Should Ask to Mitigate PV Technology Risk

This presentation outlines utility concerns when evaluating PV technologies for risk.
Date: November 9, 2010
Creator: Wohlgemuth, J.
Object Type: Presentation
System: The UNT Digital Library
Event-by-Event Fission with FREYA (open access)

Event-by-Event Fission with FREYA

The recently developed code FREYA (Fission Reaction Event Yield Algorithm) generates large samples of complete fission events, consisting of two receding product nuclei as well as a number of neutrons and photons, all with complete kinematic information. Thus it is possible to calculate arbitrary correlation observables whose behavior may provide unique insight into the fission process. The presentation first discusses the present status of FREYA, which has now been extended up to energies where pre-equilibrium emission becomes significant and one or more neutrons may be emitted prior to fission. Concentrating on {sup 239}Pu(n,f), we discuss the neutron multiplicity correlations, the dependence of the neutron energy spectrum on the neutron multiplicity, and the relationship between the fragment kinetic energy and the number of neutrons and their energies. We also briefly suggest novel fission observables that could be measured with modern detectors.
Date: November 9, 2010
Creator: Randrup, J. & Vogt, R.
Object Type: Article
System: The UNT Digital Library
CORROSION TESTING IN SIMULATED TANK SOLUTIONS (open access)

CORROSION TESTING IN SIMULATED TANK SOLUTIONS

Three simulated waste solutions representing wastes from tanks SY-102 (high nitrate, modified to exceed guidance limits), AN-107, and AY-102 were supplied by PNNL. Out of the three solutions tested, both optical and electrochemical results show that carbon steel samples corroded much faster in SY-102 (high nitrate) than in the other two solutions with lower ratios of nitrate to nitrite. The effect of the surface preparation was not as strong as the effect of solution chemistry. In areas with pristine mill-scale surface, no corrosion occurred even in the SY-102 (high nitrate) solution, however, corrosion occurred in the areas where the mill-scale was damaged or flaked off due to machining. Localized corrosion in the form of pitting in the vapor space of tank walls is an ongoing challenge to overcome in maintaining the structural integrity of the liquid waste tanks at the Savannah River and Hanford Sites. It has been shown that the liquid waste condensate chemistry influences the amount of corrosion that occurs along the walls of the storage tanks. To minimize pitting corrosion, an effort is underway to gain an understanding of the pitting response in various simulated waste solutions. Electrochemical testing has been used as an accelerated tool in …
Date: December 9, 2010
Creator: Hoffman, E.
Object Type: Report
System: The UNT Digital Library
SINGLE MOLECULE APPROACHES TO BIOLOGY, 2010 GORDON RESEARCH CONFERENCE, JUNE 27-JULY 2, 2010, ITALY (open access)

SINGLE MOLECULE APPROACHES TO BIOLOGY, 2010 GORDON RESEARCH CONFERENCE, JUNE 27-JULY 2, 2010, ITALY

The 2010 Gordon Conference on Single-Molecule Approaches to Biology focuses on cutting-edge research in single-molecule science. Tremendous technical developments have made it possible to detect, identify, track, and manipulate single biomolecules in an ambient environment or even in a live cell. Single-molecule approaches have changed the way many biological problems are addressed, and new knowledge derived from these approaches continues to emerge. The ability of single-molecule approaches to avoid ensemble averaging and to capture transient intermediates and heterogeneous behavior renders them particularly powerful in elucidating mechanisms of biomolecular machines: what they do, how they work individually, how they work together, and finally, how they work inside live cells. The burgeoning use of single-molecule methods to elucidate biological problems is a highly multidisciplinary pursuit, involving both force- and fluorescence-based methods, the most up-to-date advances in microscopy, innovative biological and chemical approaches, and nanotechnology tools. This conference seeks to bring together top experts in molecular and cell biology with innovators in the measurement and manipulation of single molecules, and will provide opportunities for junior scientists and graduate students to present their work in poster format and to exchange ideas with leaders in the field. A number of excellent poster presenters will be …
Date: July 9, 2010
Creator: Moerner, Professor William
Object Type: Article
System: The UNT Digital Library
Probabilistic Threshold Criterion (open access)

Probabilistic Threshold Criterion

The Probabilistic Shock Threshold Criterion (PSTC) Project at LLNL develops phenomenological criteria for estimating safety or performance margin on high explosive (HE) initiation in the shock initiation regime, creating tools for safety assessment and design of initiation systems and HE trains in general. Until recently, there has been little foundation for probabilistic assessment of HE initiation scenarios. This work attempts to use probabilistic information that is available from both historic and ongoing tests to develop a basis for such assessment. Current PSTC approaches start with the functional form of the James Initiation Criterion as a backbone, and generalize to include varying areas of initiation and provide a probabilistic response based on test data for 1.8 g/cc (Ultrafine) 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) and LX-17 (92.5% TATB, 7.5% Kel-F 800 binder). Application of the PSTC methodology is presented investigating the safety and performance of a flying plate detonator and the margin of an Ultrafine TATB booster initiating LX-17.
Date: March 9, 2010
Creator: Gresshoff, M & Hrousis, C A
Object Type: Article
System: The UNT Digital Library
PROBABILITY BASED CORROSION CONTROL FOR LIQUID WASTE TANKS - PART III (open access)

PROBABILITY BASED CORROSION CONTROL FOR LIQUID WASTE TANKS - PART III

The liquid waste chemistry control program is designed to reduce the pitting corrosion occurrence on tank walls. The chemistry control program has been implemented, in part, by applying engineering judgment safety factors to experimental data. However, the simple application of a general safety factor can result in use of excessive corrosion inhibiting agents. The required use of excess corrosion inhibitors can be costly for tank maintenance, waste processing, and in future tank closure. It is proposed that a probability-based approach can be used to quantify the risk associated with the chemistry control program. This approach can lead to the application of tank-specific chemistry control programs reducing overall costs associated with overly conservative use of inhibitor. Furthermore, when using nitrite as an inhibitor, the current chemistry control program is based on a linear model of increased aggressive species requiring increased protective species. This linear model was primarily supported by experimental data obtained from dilute solutions with nitrate concentrations less than 0.6 M, but is used to produce the current chemistry control program up to 1.0 M nitrate. Therefore, in the nitrate space between 0.6 and 1.0 M, the current control limit is based on assumptions that the linear model developed from …
Date: December 9, 2010
Creator: Hoffman, E. & Edwards, T.
Object Type: Report
System: The UNT Digital Library
TYPE A VERIFICATION FOR THE HIGH FLUX BEAM REACTOR UNDERGROUND UTILITIES REMOVAL PHASE 2 DF WASTE LINE REMOVAL, BNL (open access)

TYPE A VERIFICATION FOR THE HIGH FLUX BEAM REACTOR UNDERGROUND UTILITIES REMOVAL PHASE 2 DF WASTE LINE REMOVAL, BNL

5098-SR-02-0 PROJECT-SPECIFIC TYPE A VERIFICATION FOR THE HIGH FLUX BEAM REACTOR UNDERGROUND UTILITIES REMOVAL PHASE 2 DF WASTE LINE REMOVAL, BROOKHAVEN NATIONAL LABORATORY
Date: July 9, 2010
Creator: Weaver, P. C.
Object Type: Report
System: The UNT Digital Library
MiniBooNE "Windows on the Universe" (open access)

MiniBooNE "Windows on the Universe"

Progress in the last few decades has left neutrino physics with several vexing issues. Among them are the following questions: (1) Why are lepton mixing angles so different from those in the quark sector? (2) What is the most probable range of the reactor mixing angle? (3) Is the atmospheric mixing angle maximal? (4) What is the number of fermion generations? These are some of the issues that neutrino science hopes to study; this article will explore these questions as part of a more general scientific landscape, and will discuss the part MiniBooNE might play in this exploration. We discuss the current state of measurements taken by MiniBooNE, and emphasize the uniqueness of neutrino oscillations as an important probe into the 'Windows on the Universe.'
Date: December 9, 2010
Creator: Stefanski, Ray
Object Type: Article
System: The UNT Digital Library
Formalism for Neutron Cross Section Covariances in the Resonance Region Using Kernel Approximation (open access)

Formalism for Neutron Cross Section Covariances in the Resonance Region Using Kernel Approximation

We describe analytical formalism for estimating neutron radiative capture and elastic scattering cross section covariances in the resolved resonance region. We use capture and scattering kernels as the starting point and show how to get average cross sections in broader energy bins, derive analytical expressions for cross section sensitivities, and deduce cross section covariances from the resonance parameter uncertainties in the recently published Atlas of Neutron Resonances. The formalism elucidates the role of resonance parameter correlations which become important if several strong resonances are located in one energy group. Importance of potential scattering uncertainty as well as correlation between potential scattering and resonance scattering is also examined. Practical application of the formalism is illustrated on {sup 55}Mn(n,{gamma}) and {sup 55}Mn(n,el).
Date: April 9, 2010
Creator: Oblozinsky, P.; Cho, Y-S.; Matoon, C. M. & Mughabghab, S. F.
Object Type: Report
System: The UNT Digital Library
Electrospun a-Si using Liquid Silane/Polymer Inks (open access)

Electrospun a-Si using Liquid Silane/Polymer Inks

Amorphous silicon nanowires (a-SiNWs) were prepared by electrospinning cyclohexasilane (Si{sub 6}H{sub 12}) admixed with polymethylmethacrylate (PMMA) in toluene. Raman spectroscopy characterization of these wires (d {approx} 50-2000 nm) shows 350 C treatment yields a-SiNWs. Porous a-SiNWs are obtained using a volatile polymer.
Date: December 9, 2010
Creator: Schulz, Doug
Object Type: Article
System: The UNT Digital Library
A diamond detector for inertial confinement fusion X-ray bang-time measurements at the National Ignition Facility (open access)

A diamond detector for inertial confinement fusion X-ray bang-time measurements at the National Ignition Facility

An instrument has been developed to measure X-ray bang-time for inertial confinement fusion capsules; the time interval between the start of the laser pulse and peak X-ray emission from the fuel core. The instrument comprises chemical vapor deposited polycrystalline diamond photoconductive X-ray detectors with highly ordered pyrolytic graphite X-ray monochromator crystals at the input. Capsule bang-time can be measured in the presence of relatively high thermal and hard X-ray background components due to the selective band pass of the crystals combined with direct and indirect X-ray shielding of the detector elements. A five channel system is being commissioned at the National Ignition Facility at Lawrence Livermore National Laboratory for implosion optimization measurements as part of the National Ignition Campaign. Characteristics of the instrument have been measured demonstrating that X-ray bang-time can be measured with {+-} 30ps precision, characterizing the soft X-ray drive to +/- 1eV or 1.5%.
Date: November 9, 2010
Creator: MacPhee, A. G.; Brown, C.; Burns, S.; Celeste, J.; Glenzer, S. H.; Hey, D. et al.
Object Type: Article
System: The UNT Digital Library
Laboratory Calibration of Density-Dependent Lines in the EUV and Soft X-Ray Regions (open access)

Laboratory Calibration of Density-Dependent Lines in the EUV and Soft X-Ray Regions

We analyzed spectral data of Fe XXII and Ar XIV from laboratory sources in which the electron density varies by several orders of magnitude to help benchmark density-sensitive emission lines useful for astrophysics and to test the atomic models underlying the diagnostic line ratios. We found excellent agreement for Fe XXII, but poorer agreement for Ar XIV. A number of astrophysically important emission lines are sensitive to electron density in the EUV and soft X-ray regions. Lines from Fe XXII, for example, have been used in recent years as diagnostics of stellar coronae, such as the active variable AB Dor, Capella, and EX Hya (Sanz-Forcada et al. 2003, Mewe et al. 2001, Mauche et al. 2003). Here we report spectral data of Fe XXII and Ar XIV from laboratory sources in which the electron density is known from either K-shell density diagnostics (for electron beam ion traps) or from non-spectroscopic means (tokamaks), ranging from 5 x 10{sup 10} cm{sup -3} to 5 x 10{sup 14} cm{sup -3}. These measurements were used to test the atomic data underlying the density diagnostic line ratios, complementing earlier work (Chen et al. 2004).
Date: December 9, 2010
Creator: Lepson, J K; Beiersdorfer, P; Gu, M F & Desai, P
Object Type: Article
System: The UNT Digital Library
Phase Segregation in Polystyrene?Polylactide Blends (open access)

Phase Segregation in Polystyrene?Polylactide Blends

Spun-cast films of polystyrene (PS) blended with polylactide (PLA) were visualized and characterized using atomic force microscopy (AFM) and synchrotron-based X-ray photoemission electron microscopy (X-PEEM). The composition of the two polymers in these systems was determined by quantitative chemical analysis of near-edge X-ray absorption signals recorded with X-PEEM. The surface morphology depends on the ratio of the two components, the total polymer concentration, and the temperature of vacuum annealing. For most of the blends examined, PS is the continuous phase with PLA existing in discrete domains or segregated to the air?polymer interface. Phase segregation was improved with further annealing. A phase inversion occurred when films of a 40:60 PS:PLA blend (0.7 wt percent loading) were annealed above the glass transition temperature (Tg) of PLA.
Date: June 9, 2010
Creator: Leung, Bonnie; Hitchcock, Adam; Brash, John; Scholl, Andreas & Doran, Andrew
Object Type: Article
System: The UNT Digital Library
Design of Genomic Signatures of Pathogen Identification & Characterization (open access)

Design of Genomic Signatures of Pathogen Identification & Characterization

This chapter will address some of the many issues associated with the identification of signatures based on genomic DNA/RNA, which can be used to identify and characterize pathogens for biodefense and microbial forensic goals. For the purposes of this chapter, we define a signature as one or more strings of contiguous genomic DNA or RNA bases that are sufficient to identify a pathogenic target of interest at the desired resolution and which could be instantiated with particular detection chemistry on a particular platform. The target may be a whole organism, an individual functional mechanism (e.g., a toxin gene), or simply a nucleic acid indicative of the organism. The desired resolution will vary with each program's goals but could easily range from family to genus to species to strain to isolate. The resolution may not be taxonomically based but rather pan-mechanistic in nature: detecting virulence or antibiotic-resistance genes shared by multiple microbes. Entire industries exist around different detection chemistries and instrument platforms for identification of pathogens, and we will only briefly mention a few of the techniques that we have used at Lawrence Livermore National Laboratory (LLNL) to support our biosecurity-related work since 2000. Most nucleic acid based detection chemistries involve …
Date: February 9, 2010
Creator: Slezak, T.; Gardner, S.; Allen, J.; Vitalis, E. & Jaing, C.
Object Type: Book
System: The UNT Digital Library