Measurements of the Motion of Plasma Filaments in a Plasma Ball (open access)

Measurements of the Motion of Plasma Filaments in a Plasma Ball

Measurements were made of the motion of the filamentary structures in a plasma ball using high speed cameras and other optical detectors. These filaments traverse the ball radially at ~106 cm/sec at the driving frequency of ~26 kHz, and drift upward through the ball at ~1 cm/sec. Varying the applied high voltage and frequency caused the number, length, and diameter of the filaments to change. A custom plasma ball was constructed to observe the effects of varying gas pressure and species on the filament structures.
Date: January 26, 2010
Creator: M. Campanell, J. Laird, T. Provost, S. Vasquez, S.J. Zweben
Object Type: Report
System: The UNT Digital Library
Calibration of a High Resolution Soft X-ray Spectrometer (open access)

Calibration of a High Resolution Soft X-ray Spectrometer

A high resolution grating spectrometer (HRGS) with 2400 line/mm variable line spacing grating for the 10-50 {angstrom} wavelength range has been designed for laser-produced plasma experiments at the Lawrence Livermore National Laboratory (LLNL). The spectrometer has a large radius of curvature, R=44.3 m, is operated at a 2{sup o} grazing angle and can record high signal-to-noise spectra when used with a low-noise, cooled, charge-coupled device detector. The instrument can be operated with a 10-25 {micro}m wide slit to achieve the best spectral resolving power on laser plasma sources, approaching 2000, or in slitless mode with a small symmetrical emission source. Results will be presented for the spectral response of the spectrometer cross-calibrated at the LLNL Electron Beam Ion Trap facility using the broadband x-ray energy EBIT Calorimeter Spectrometer (ECS).
Date: January 26, 2010
Creator: Dunn, J; Beiersdorfer, P; Brown, G V & Magee, E W
Object Type: Article
System: The UNT Digital Library
LLNL Genomic Assessment: Viral and Bacterial Sequencing Needs for TMTI, Task 1.4.2 Report (open access)

LLNL Genomic Assessment: Viral and Bacterial Sequencing Needs for TMTI, Task 1.4.2 Report

Good progress has been made on both bacterial and viral sequencing by the TMTI centers. While access to appropriate samples is a limiting factor to throughput, excellent progress has been made with respect to getting agreements in place with key sources of relevant materials. Sharing of sequenced genomes funded by TMTI has been extremely limited to date. The April 2010 exercise should force a resolution to this, but additional managerial pressures may be needed to ensure that rapid sharing of TMTI-funded sequencing occurs, regardless of collaborator constraints concerning ultimate publication(s). Policies to permit TMTI-internal rapid sharing of sequenced genomes should be written into all TMTI agreements with collaborators now being negotiated. TMTI needs to establish a Web-based system for tracking samples destined for sequencing. This includes metadata on sample origins and contributor, information on sample shipment/receipt, prioritization by TMTI, assignment to one or more sequencing centers (including possible TMTI-sponsored sequencing at a contributor site), and status history of the sample sequencing effort. While this system could be a component of the AFRL system, it is not part of any current development effort. Policy and standardized procedures are needed to ensure appropriate verification of all TMTI samples prior to the investment …
Date: January 26, 2010
Creator: Slezak, T; Borucki, M; Lam, M; Lenhoff, R & Vitalis, E
Object Type: Report
System: The UNT Digital Library
Alternate Alpha Induced Reactions for NIF Radiochemistry (open access)

Alternate Alpha Induced Reactions for NIF Radiochemistry

Radiochemical analysis of NIF capsule residues has been identified as a potential diagnostic of NIF capsule performance. In particular, alpha-induced nuclear reactions that occur on tracer elements added to the NIF capsule have been shown through simulation to be a very sensitive diagnostic for mix. The short range of the alpha particles makes them representative of the hot spot where they are created through the fusion of deuterium and tritium. Reactions on elements doped into the innermost part of the capsule ablator would therefore be sensitive to material that had mixed into the hot spot. Radiochemical determinations of activated detector elements may perhaps be the only true measure of mix that occurs in a NIF capsule, particularly in cases when the capsule fails.
Date: February 26, 2010
Creator: Shaughnessy, D A; Moody, K J & Bernstein, L A
Object Type: Report
System: The UNT Digital Library
EXAMINATION OF SHIPPING PACKAGES 9975-01968, 9975-04353 AND 9975-06870 (open access)

EXAMINATION OF SHIPPING PACKAGES 9975-01968, 9975-04353 AND 9975-06870

Three 9975 shipping packages were examined to investigate the non-conforming condition of an axial air gap greater than 1 inch. This condition typically indicates the presence of excess moisture in the fiberboard overpack, and may be accompanied by degradation in the fiberboard properties. In the case of these three packages, no excess moisture was present, and the fiberboard was not visibly degraded. However, the lower fiberboard assembly from 9975-06870 was separated into two pieces. The lead shield from 9975-04353 was heavily corroded, while the shield from 9975-01968 had very little corrosion. In the case of 9975-06870, the shield was covered by a stainless steel sleeve, and the condition of the lead was not observed. No other conditions of concern were observed in these three packages.
Date: April 26, 2010
Creator: Daugherty, W.
Object Type: Report
System: The UNT Digital Library
TANK OPERATIONS CONTRACT CONSTRUCTION MANAGEMENT METHODOLOGY (open access)

TANK OPERATIONS CONTRACT CONSTRUCTION MANAGEMENT METHODOLOGY

None
Date: February 26, 2010
Creator: Lesko, K. F. & Berriochoa, M. V.
Object Type: Article
System: The UNT Digital Library
TANK OPERATIONS CONTRACT CONSTRUCTION MANAGEMENT METHODOLOGY UTILIZING THE AGENCY METHOD OF CONSTRUCTION MANAGEMENT (open access)

TANK OPERATIONS CONTRACT CONSTRUCTION MANAGEMENT METHODOLOGY UTILIZING THE AGENCY METHOD OF CONSTRUCTION MANAGEMENT

Washington River Protection Solutions, LLC (WRPS) has faced significant project management challenges in managing Davis-Bacon construction work that meets contractually required small business goals. The unique challenge is to provide contracting opportunities to multiple small business constructioin subcontractors while performing high hazard work in a safe and productive manner. Previous to the WRPS contract, construction work at the Hanford Tank Farms was contracted to large companies, while current Department of Energy (DOE) Contracts typically emphasize small business awards. As an integral part of Nuclear Project Management at Hanford Tank Farms, construction involves removal of old equipment and structures and installation of new infrastructure to support waste retrieval and waste feed delivery to the Waste Treatment Plant. Utilizing the optimum construction approach ensures that the contractors responsible for this work are successful in meeting safety, quality, cost and schedule objectives while working in a very hazardous environment. This paper descirbes the successful transition from a traditional project delivery method that utilized a large business general contractor and subcontractors to a new project construction management model that is more oriented to small businesses. Construction has selected the Agency Construction Management Method (John E Schaufelberger, Len Holm, "Management of Construction Projects, A Constructor's …
Date: February 26, 2010
Creator: Lesko, K. F. & Berriochoa, M. V.
Object Type: Article
System: The UNT Digital Library
Simple Model of the (alpha)(omega) Dynamo: Self-Excited Spheromaks (open access)

Simple Model of the (alpha)(omega) Dynamo: Self-Excited Spheromaks

The astrophysical {alpha}{omega} dynamo converting angular momentum to magnetic energy can be interpreted as a self-excited Faraday dynamo together with magnetic relaxation coupling the dynamo poloidal field to the toroidal field produced by dynamo currents. Since both toroidal and poloidal fields are involved, the system can be modeled as helicity creation and transport, in a spheromak plasma configuration in quasi-equilibrium on the time scale of changes in magnetic energy. Neutral beams or plasma gun injection across field lines could create self-excited spheromaks in the laboratory.
Date: January 26, 2010
Creator: Fowler, T K
Object Type: Report
System: The UNT Digital Library
Comprehensive Characterization of Voids and Microstructure in TATB-based Explosives from 10 nm to 1 cm: Effects of Temperature Cycling and Compressive Creep (open access)

Comprehensive Characterization of Voids and Microstructure in TATB-based Explosives from 10 nm to 1 cm: Effects of Temperature Cycling and Compressive Creep

This paper outlines the characterization of voids and Microstructure in TATB-based Explosives over several orders of magnitude, from sizes on the order of 10 nm to about 1 cm. This is accomplished using ultra small angle x-ray scattering to investigate voids from a few nm to a few microns, ultra small angle neutron scattering for voids from 100 nm to 10 microns, and x-ray computed microtomography to investigate microstructure from a few microns to a few centimeters. The void distributions of LX-17 are outlined, and the microstructure of LX-17 is presented. Temperature cycling and compressive creep cause drastically different damage to the microstructure. Temperature cycling leads to a volume expansion (ratchet growth) in TATB-based explosives, and x-ray scattering techniques that are sensitive to sizes up to a few microns indicated changes to the void volume distribution that had previously accounted for most, but not all of the change in density. This paper presents the microstructural damage larger than a few microns caused by ratchet growth. Temperature cycling leads to void creation in the binder poor regions associated with the interior portion of formulated prills. Conversely, compressive creep causes characteristically different changes to microstructure; fissures form at binder-rich prill boundaries prior …
Date: February 26, 2010
Creator: Willey, T. M.; Lauderbach, L.; Gagliardi, F.; Cunningham, B.; Lorenz, K. T.; Lee, J. I. et al.
Object Type: Article
System: The UNT Digital Library
Laser-induced Ramp Compression of Tantalum and Iron to Over 300 GPa: EOS and X-ray Diffraction (open access)

Laser-induced Ramp Compression of Tantalum and Iron to Over 300 GPa: EOS and X-ray Diffraction

None
Date: January 26, 2010
Creator: Eggert, J. H.; Bastea, M.; Braun, D.; Fujino, D.; Rygg, R.; Smith, R. et al.
Object Type: Article
System: The UNT Digital Library
Effects of Temperature and Contamination on Mpcms Electrodes in 241-Ay-101 and 241-an-107 Tank Waste Simulants (open access)

Effects of Temperature and Contamination on Mpcms Electrodes in 241-Ay-101 and 241-an-107 Tank Waste Simulants

This report documents the results of tests designed to characterize the relationship between temperature and the measured potential of electrodes installed on multi-probe corrosion monitoring systems in waste tanks. This report also documents the results of tests designed to demonstrate the impact of liquid in-leakage into electrode bodies as well as the contamination of primary reference electrodes by diffusion through the electrode tip.
Date: March 26, 2010
Creator: Dahl, M. M.; Philo, S. L.; Edgemon, G. L.; Bell, J. L. S. & Moore, C. G.
Object Type: Report
System: The UNT Digital Library
Limits on superconductivity-related magnetization in Sr 2RuO 4 and PrOs 4Sb 12 from scanning SQUID microscopy (open access)

Limits on superconductivity-related magnetization in Sr 2RuO 4 and PrOs 4Sb 12 from scanning SQUID microscopy

We present scanning SQUID microscopy data on the superconductors Sr{sub 2}RuO{sub 4} (T{sub c} = 1.5 K) and PrOs{sub 4}Sb{sub 12} (T{sub c} = 1.8 K). In both of these materials, superconductivity-related time-reversal symmetry-breaking fields have been observed by muon spin rotation; our aim was to visualize the structure of these fields. However in neither Sr{sub 2}RuO{sub 4} nor PrOs{sub 4}Sb{sub 12} do we observe spontaneous superconductivity-related magnetization. In Sr{sub 2}RuO{sub 4}, many experimental results have been interpreted on the basis of a p{sub x} {+-} ip{sub y} superconducting order parameter. This order parameter is expected to give spontaneous magnetic induction at sample edges and order parameter domain walls. Supposing large domains, our data restrict domain wall and edge fields to no more than {approx}0.1% and {approx}0.2% of the expected magnitude, respectively. Alternatively, if the magnetization is of the expected order, the typical domain size is limited to {approx}30 nm for random domains, or {approx} 500 nm for periodic domains.
Date: August 26, 2010
Creator: Moler, Kathryn
Object Type: Article
System: The UNT Digital Library
No Prejudice in Space (open access)

No Prejudice in Space

We present a summary of recent results obtained from a scan of the 19-dimensional parameter space of the pMSSM and its implications for dark matter searches. We have generated a large set of points in parameter space (which we call 'models') for the 19-parameter CP-conserving pMSSM, where MFV has been assumed. We subjected these models to numerous experimental and theoretical constraints to obtain a set of {approx}68 K models which are consistent with existing data. We attempted to be somewhat conservative in our implementation of these constraints; in particular we only demanded that the relic density of the LSP not be greater than the measured value of {Omega}H{sup 2} for non-baryonic dark matter, rather than assuming that the LSP must account for the entire observed relic density. Examining the properties of the neutralinos in these models, we find that many are relatively pure gauge eigenstates with Higgsinos being the most common, followed by Winos. The relative prevalence of Higgsino and Wino LSPs leads many of our models to have a chargino as nLSP, often with a relatively small mass splitting between this nLSP and the LSP; this has important consequences in both collider and astroparticle phenomenology. We find that, in …
Date: August 26, 2010
Creator: Cotta, R. C.; Gainer, J. S.; Hewett, J. L. & Rizzo, T. G.
Object Type: Article
System: The UNT Digital Library
A Single-Shot Method for Measuring Femtosecond Bunch Length in Linac-Based Free-Electron Lasers (open access)

A Single-Shot Method for Measuring Femtosecond Bunch Length in Linac-Based Free-Electron Lasers

There is growing interest in the generation and characterization of femtosecond and subfemtosecond pulses from linac-based free-electron lasers (FELs). In this report, following the method of Ricci and Smith [Phys. Rev. ST Accel. Beams 3, 032801 (2000)], we investigate the measurement of the longitudinal bunch profile of an ultrashort electron bunch produced by these FELs. We show that this method can be applied in a straightforward manner at x-ray FEL facilities such as the Linac Coherent Light Source by slightly adjusting the second bunch compressor followed by running the bunch on an rf zero-crossing phase of the final linac. We find that the linac wakefield strongly perturbs the measurement, and through analysis show that it can be compensated in a simple way. We demonstrate the effectiveness of this method and wakefield compensation through numerical simulations, including effects of coherent synchrotron radiation and longitudinal space charge. When used in conjunction with a high-resolution electron spectrometer, this method potentially reveals the temporal profile of the electron beam down to the femtosecond and subfemotsecond scale.
Date: August 26, 2010
Creator: Huang, Z.; Bane, K.; Ding, Y. & Emma, P.
Object Type: Article
System: The UNT Digital Library
SXR Continuum Radiation Transmitted Through Metallic Filters: An Analytical Approach To Fast Electron Temperature Measurements (open access)

SXR Continuum Radiation Transmitted Through Metallic Filters: An Analytical Approach To Fast Electron Temperature Measurements

A new set of analytic formulae describes the transmission of soft X-ray (SXR) continuum radiation through a metallic foil for its application to fast electron temperature measurements in fusion plasmas. This novel approach shows good agreement with numerical calculations over a wide range of plasma temperatures in contrast with the solutions obtained when using a transmission approximated by a single-Heaviside function [S. von Goeler, Rev. Sci. Instrum., 20, 599, (1999)]. The new analytic formulae can improve the interpretation of the experimental results and thus contribute in obtaining fast teperature measurements in between intermittent Thomson Scattering data.
Date: August 26, 2010
Creator: Delgado-Aparicio, L.; Tritz, K.; Kramer, T.; Stutman, D.; Finkentha, M.; Hill, K. et al.
Object Type: Report
System: The UNT Digital Library
'Micromanaging de Sitter holography' (open access)

'Micromanaging de Sitter holography'

We develop tools to engineer de Sitter vacua with semi-holographic duals, using elliptic fibrations and orientifolds to uplift Freund-Rubin compactifications with CFT duals. The dual brane construction is compact and constitutes a microscopic realization of the dS/dS correspondence, realizing d-dimensional de Sitter space as a warped compactification down to (d-1)-dimensional de Sitter gravity coupled to a pair of large-N matter sectors. This provides a parametric microscopic interpretation of the Gibbons-Hawking entropy. We illustrate these ideas with an explicit class of examples in three dimensions, and describe ongoing work on four-dimensional constructions. The Gibbons-Hawking entropy of the de Sitter horizon [1] invites a microscopic interpretation and a holographic formulation of inflating spacetimes. Much progress was made in the analogous problem in black hole physics using special black holes in string theory whose microstates could be reliably counted, such as those analyzed in [2,3]; this led to the AdS/CFT correspondence [4]. In contrast, a microscopic understanding of the entropy of de Sitter space is more difficult for several reasons including its potential dynamical connections to other backgrounds (metastability), the absence of a non-fluctuating timelike boundary, and the absence of supersymmetry. In this paper, we develop a class of de Sitter constructions in …
Date: August 26, 2010
Creator: Dong, Xi; Horn, Bart; /SLAC /Stanford U., Phys. Dept. /Santa Barbara, KITP; Silverstein, Eva; /Santa Barbara, KITP /SLAC /Stanford U., Phys. Dept.; Torroba, Gonzalo et al.
Object Type: Article
System: The UNT Digital Library
RAPID SEPARATION METHOD FOR 237NP AND PU ISOTOPES IN LARGE SOIL SAMPLES (open access)

RAPID SEPARATION METHOD FOR 237NP AND PU ISOTOPES IN LARGE SOIL SAMPLES

A new rapid method for the determination of {sup 237}Np and Pu isotopes in soil and sediment samples has been developed at the Savannah River Site Environmental Lab (Aiken, SC, USA) that can be used for large soil samples. The new soil method utilizes an acid leaching method, iron/titanium hydroxide precipitation, a lanthanum fluoride soil matrix removal step, and a rapid column separation process with TEVA Resin. The large soil matrix is removed easily and rapidly using this two simple precipitations with high chemical recoveries and effective removal of interferences. Vacuum box technology and rapid flow rates are used to reduce analytical time.
Date: July 26, 2010
Creator: Maxwell, S.; Culligan, B. & Noyes, G.
Object Type: Article
System: The UNT Digital Library
Topological Insulators and Nematic Phases from Spontaneous Symmetry Breaking in (open access)

Topological Insulators and Nematic Phases from Spontaneous Symmetry Breaking in

We investigate the stability of a quadratic band-crossing point (QBCP) in 2D fermionic systems. At the non-interacting level, we show that a QBCP exists and is topologically stable for a Berry flux {-+}2{pi}, if the point symmetry group has either fourfold or sixfold rotational symmetries. This putative topologically stable free-fermion QBCP is marginally unstable to arbitrarily weak shortrange repulsive interactions. We consider both spinless and spin-1/2 fermions. Four possible ordered states result: a quantum anomalous Hall phase, a quantum spin Hall phase, a nematic phase, and a nematic-spin-nematic phase.
Date: May 26, 2010
Creator: Sun, K.
Object Type: Article
System: The UNT Digital Library
AdS/CFT and Large-N Volume Independence (open access)

AdS/CFT and Large-N Volume Independence

We study the Eguchi-Kawai reduction in the strong-coupling domain of gauge theories via the gravity dual of N=4 super-Yang-Mills on R{sup 3} x S{sup 1}. We show that D-branes geometrize volume independence in the center-symmetric vacuum and give supergravity predictions for the range of validity of reduced large-N models at strong coupling.
Date: August 26, 2010
Creator: Poppitz, Erich; U., /Toronto; Unsal, Mithat & /SLAC /Stanford U., Phys. Dept.
Object Type: Article
System: The UNT Digital Library
Realization of Center Symmetry in Two Adjoint Flavor Large-N Yang-Mills (open access)

Realization of Center Symmetry in Two Adjoint Flavor Large-N Yang-Mills

We report on the results of numerical simulations of SU(N) lattice Yang Mills with two flavors of (light) Wilson fermion in the adjoint representation. We analytically and numerically address the question of center symmetry realization on lattices with {Lambda} sites in each direction in the large-N limit. We show, by a weak coupling calculation that, for massless fermions, center symmetry realization is independent of {Lambda}, and is unbroken. Then, we extend our result by conducting simulations at non zero mass and finite gauge coupling. Our results indicate that center symmetry is intact for a range of fermion mass in the vicinity of the critical line on lattices of volume 2{sup 4}. This observation makes it possible to compute infinite volume physical observables using small volume simulations in the limit N {yields} {infinity}, with possible applications to the determination of the conformal window in gauge theories with adjoint fermions.
Date: August 26, 2010
Creator: Catterall, Simon; U., /Syracuse; Galvez, Richard; U., /Syracuse; Unsal, Mithat & /SLAC /Stanford U., Phys. Dept.
Object Type: Article
System: The UNT Digital Library
FPGA Based Real-time Network Traffic Analysis using Traffic Dispersion Patterns (open access)

FPGA Based Real-time Network Traffic Analysis using Traffic Dispersion Patterns

The problem of Network Traffic Classification (NTC) has attracted significant amount of interest in the research community, offering a wide range of solutions at various levels. The core challenge is in addressing high amounts of traffic diversity found in today's networks. The problem becomes more challenging if a quick detection is required as in the case of identifying malicious network behavior or new applications like peer-to-peer traffic that have potential to quickly throttle the network bandwidth or cause significant damage. Recently, Traffic Dispersion Graphs (TDGs) have been introduced as a viable candidate for NTC. The TDGs work by forming a network wide communication graphs that embed characteristic patterns of underlying network applications. However, these patterns need to be quickly evaluated for mounting real-time response against them. This paper addresses these concerns and presents a novel solution for real-time analysis of Traffic Dispersion Metrics (TDMs) in the TDGs. We evaluate the dispersion metrics of interest and present a dedicated solution on an FPGA for their analysis. We also present analytical measures and empirically evaluate operating effectiveness of our design. The mapped design on Virtex-5 device can process 7.4 million packets/second for a TDG comprising of 10k flows at very high accuracies …
Date: March 26, 2010
Creator: Khan, F.; Gokhale, M. & Chuah, C. N.
Object Type: Article
System: The UNT Digital Library
e+ e- Factory Developments (open access)

e+ e- Factory Developments

The impressive performance of current (KEKB) and recent (PEP-II) B-Factory colliders has increased interest in developing even higher luminosity B-factories. Two new designs are being developed (SuperKEKB and SuperB). Both designs plan to deliver a luminosity in the range of 1 x 10{sup 36} cm{sup -2}s{sup -1}, nearly 100 times the present B-factory level. Achieving this high luminosity requires high-current beams and short bunch lengths and/or a new way of colliding the beams. The SuperB design employs a crabbed magnetic waist with a large crossing angle and the SuperKEKB design is looking at crab cavities with high-current beams and/or a travelling focus. I describe the designs being studied to achieve the high luminosity needed for the next generation of B-Factories.
Date: August 26, 2010
Creator: Sullivan, Michael
Object Type: Article
System: The UNT Digital Library
Observation of the three-body rare decay B-> J/psi phi K (open access)

Observation of the three-body rare decay B-> J/psi phi K

The authors report the study of the B meson decays B{sup {+-}} {yields} J/{psi}{phi}K{sup {+-}}, B{sup 0} {yields} J/{psi}{phi}K{sup 0} using 433 million of B{bar B} events collected at the {Upsilon}(4S) resonance with the BABAR detector at the PEP-II e{sup +}e{sup -} asymmetric-energy collider. They obtain the branching fraction measurements: {Beta}(B{sup {+-}} {yields} J{psi}{phi}K{sup {+-}}) = (5.6 {+-} 0.9(stat) {+-} 0.3(sys)) x 10{sup -5}, {Beta}(B{sup {+-}} {yields} J{psi}{phi}K{sup 0}) = (5.4 {+-} 1.2(stat) {+-} 0.4(sys)) x 10{sup -5}.
Date: August 26, 2010
Creator: Aubert, B.
Object Type: Article
System: The UNT Digital Library
Mechanics of Individual, Isolated Vortices in a Cuprate Superconductor (open access)

Mechanics of Individual, Isolated Vortices in a Cuprate Superconductor

None
Date: May 26, 2010
Creator: Auslaender, O.M.
Object Type: Article
System: The UNT Digital Library