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Laser Plasma Interactions at Intensities from 10{sup 12}W/cm{sup 2} to 10{sup 21} W/cm{sup 2}

Description: A tutorial introduction is given to some important physics and current challenges in laser plasma interactions. The topics are chosen to illustrate a few of John Dawson's many pioneering contributions to the physics and modeling of plasmas. In each case, a current frontier is also briefly discussed, including the .53{micro}m option for laser fusion, kinetic inflation of instability levels, and new regimes accessed with ultra-high power lasers.
Date: November 5, 2002
Creator: Kruer, W L
Partner: UNT Libraries Government Documents Department
open access

Interactive View-Dependent Rendering of Large Isosurfaces

Description: We present an algorithm for interactively extracting and rendering isosurfaces of large volume datasets in a view-dependent fashion. A recursive tetrahedral mesh refinement scheme, based on longest edge bisection, is used to hierarchically decompose the data into a multiresolution structure. This data structure allows fast extraction of arbitrary isosurfaces to within user specified view-dependent error bounds. A data layout scheme based on hierarchical space filling curves provides access to t… more
Date: November 19, 2002
Creator: Gregorski, B; Duchaineau, M; Lindstrom, P; Pascucci, V & Joy, K I
Partner: UNT Libraries Government Documents Department
open access

20% Partial Siberian Snake in the AGS.

Description: An 11.4% partial Siberian snake was used to successfully accelerate polarized proton through a strong intrinsic depolarizing spin resonance in the AGS. No noticeable depolarization was observed. This opens up the possibility of using a 20% to 30% partial Siberian snake in the AGS to overcome all weak and strong depolarizing spin resonances. Some design and operation issues of the new partial Siberian snake are discussed.
Date: November 6, 2002
Creator: Huang, H.; Bai, M.; Brown, K. A.; Glenn, W.; Luccio, A. U.; MacKay, W. W. et al.
Partner: UNT Libraries Government Documents Department
open access

The Godunov-Inverse Iteration: A Fast and Accurate Solution to the Symmetric Tridiagonal Eigenvalue Problem.

Description: We present a new hybrid algorithm based on Godunov's method for computing eigenvectors of symmetric tridiagonal matrices and Inverse Iteration, which we call the Godunov-Inverse Iteration Algorithm. We use eigenvectors computed according to Godunov's method as starting vectors in the Inverse Iteration, replacing any nonnumeric elements of the Godunov eigenvectors with random uniform numbers. We use the right-hand bounds of the Ritz intervals found by the bisection method as Inverse Iteration sh… more
Date: November 27, 2002
Creator: Matsekh, Anna M.
Partner: UNT Libraries Government Documents Department
open access

Modeling daily flow patterns individuals to characterize disease spread

Description: The effect of an individual's travels throughout a day on the spread of disease is examined using a deterministic SIR model. We determine which spatial and demographic characteristics most contribute to the disease spread and whether the progression of the disease can be slowed by appropriate vaccination of people belonging to a specific location-type.
Date: November 17, 2002
Creator: Smallwood, J. (Jeanine); Hyman, J. M. (James M.) & Mirchandani, Pitu B.
Partner: UNT Libraries Government Documents Department
open access

Strategies and tools for whole genome alignments

Description: The availability of the assembled mouse genome makespossible, for the first time, an alignment and comparison of two largevertebrate genomes. We have investigated different strategies ofalignment for the subsequent analysis of conservation of genomes that areeffective for different quality assemblies. These strategies were appliedto the comparison of the working draft of the human genome with the MouseGenome Sequencing Consortium assembly, as well as other intermediatemouse assemblies. Our meth… more
Date: November 25, 2002
Creator: Couronne, Olivier; Poliakov, Alexander; Bray, Nicolas; Ishkhanov,Tigran; Ryaboy, Dmitriy; Rubin, Edward et al.
Partner: UNT Libraries Government Documents Department
open access

Physical and Computational Modeling for Chemical and Biological Weapons Airflow Applications

Description: There is a need for information on dispersion and infiltration of chemical and biological agents in complex building environments. A recent collaborative study conducted at the Idaho National Engineering and Environmental Laboratory (INEEL) and Bechtel Corporation Research and Development had the objective of assessing computational fluid dynamics (CFD) models for simulation of flow around complicated buildings through a comparison of experimental and numerical results. The test facility used i… more
Date: November 1, 2002
Creator: McEligot, Donald Marinus; Mc Creery, Glenn Ernest; Pink, Robert John; Barringer, C. & Knight, K. J.
Partner: UNT Libraries Government Documents Department
open access

An integrated mechanical design concept for the final focusingregion for the HIF point design

Description: A design study was undertaken to develop a ''first cut'' integrated mechanical design concept of the final focusing region for a conceptual IFE power plant that considers the major issues which must be addressed in an integrated driver and chamber system. The conceptual design in this study requires a total of 120 beamlines located in two conical arrays attached on the sides of the target chamber 180 degrees apart. Each beamline consists of four large-aperture superconducting quadrupole magnets… more
Date: November 21, 2002
Creator: Brown, T.; Sabbi, G. L.; Barnard, J. J.; Heitzenroeder, P.; Chun, J.; Schmidt, J. et al.
Partner: UNT Libraries Government Documents Department
open access

Molecular Foundry Workshop draws overflow crowd to BerkeleyLab

Description: Nanoscale science and technology is now one of the top research priorities in the United States. With this background, it is no surprise that an overflow crowd or more than 350 registrants filled two auditoriums to hear about and contribute ideas for the new Molecular Foundry during a two-day workshop at the Lawrence Berkeley National Laboratory (Berkeley Lab). Scheduled to open for business at Berkeley Labin early 2006, the Molecular Foundry is one of three Nanoscale Science Research Centers (… more
Date: November 27, 2002
Creator: Robinson, Art
Partner: UNT Libraries Government Documents Department
open access

Electron Flood Charge Compensation Device for Ion Trap Secondary Ion Mass Spectrometry

Description: During secondary ion mass spectrometry (SIMS) analyses of organophosphorous compounds adsorbed onto soils, the measured anion signals were lower than expected and it was hypothesized that the low signals could be due to sample charging. An electron flood gun was designed, constructed and used to investigate sample charging of these and other sample types. The flood gun was integrated into one end cap of an ion trap secondary ion mass spectrometer and the design maintained the geometry of the se… more
Date: November 1, 2002
Creator: Appelhans, Anthony David; Ward, Michael Blair & Olson, John Eric
Partner: UNT Libraries Government Documents Department
open access

Fission barrier properties, resonance fluctuations and isomer fission cross-sections.

Description: Although the main picture of fission bamer physics was established some time ago many of the details still have to be settled. Consequently, the application to evaluation of crosssections of unmeasurable or exotic nuclides and their excited states is still in its early stages. In this paper I consider some of these details and explore the possibility of quantitative estimation of fission cross-sections
Date: November 27, 2002
Creator: Lynn, J. E. (J. Eric) & Hayes, A. C. (Anna C.)
Partner: UNT Libraries Government Documents Department
open access

Climate change, insurance, and the buildings sector: Technological synergisms between adaptation and mitigation

Description: Examining the intersection of risk analysis and sustainable energy strategies reveals numerous examples of energy efficient and renewable energy technologies that offer insurance loss-prevention benefits. The growing threat of climate change provides an added motivation for the risk community to better understand this area of opportunity. While analyses of climate change mitigation typically focus on the emissions-reduction characteristics of sustainable energy technologies, less often recogniz… more
Date: November 1, 2002
Creator: Mills, Evan
Partner: UNT Libraries Government Documents Department
open access

Compression dynamics of an indirect drive fast ignition target

Description: In an x-ray driven reentrant cone fast ignition target the x-ray spectrum contains a high energy component that cause preheating of the reentrant cone and mixing of its gold into the collapsing shell. Direct laser drive might avoid this problem.
Date: November 12, 2002
Creator: Stephens, R. B.; Hatchett, S. P.; Turner, R. E.; Tanaka, K. A.; Kodama, R.; Kodama, R. et al.
Partner: UNT Libraries Government Documents Department
open access

Nonlinear dynamics in flow through unsaturated fractured-porous media: Status and perspectives

Description: The need has long been recognized to improve predictions of flow and transport in partially saturated heterogeneous soils and fractured rock of the vadose zone for many practical applications, such as remediation of contaminated sites, nuclear waste disposal in geological formations, and climate predictions. Until recently, flow and transport processes in heterogeneous subsurface media with oscillating irregularities were assumed to be random and were not analyzed using methods of nonlinear dyn… more
Date: November 27, 2002
Creator: Faybishenko, Boris
Partner: UNT Libraries Government Documents Department
open access

{sup 18}O composition of CO{sub 2} and H{sub 2}O ecosystem pools and fluxes in a tallgrass prairie: Simulations and comparisons to measurements

Description: In this paper we describe measurements and modeling of 18O in CO2 and H2O pools and fluxes at a tallgrass prairie site in Oklahoma. We present measurements of the d18O value of leaf water, depth-resolved soil water, atmospheric water vapor, and Keeling plot d18O intercepts for net soil-surface CO2 and ecosystem CO2 and H2O fluxes during three periods of the 2000 growing season. Daytime discrimination against C18OO, as calculated from measured above-canopy CO2 and d18O gradients, is also present… more
Date: November 1, 2002
Creator: Riley, William J.; Still, Christopher J.; Helliker, Brent R.; Ribas-Carbo, Miguel & Berry, Joseph A.
Partner: UNT Libraries Government Documents Department
open access

Betatron motion with coupling of horizontal and vertical degrees of freedom

Description: The Courant-Snyder parameterization of one-dimensional linear betatron motion is generalized to two-dimensional coupled linear motion. To represent the 4 x 4 symplectic transfer matrix the following ten parameters were chosen: four beta-functions, four alpha-functions and two betatron phase advances which have a meaning similar to the Courant-Snyder parameterization. Such a parameterization works equally well for weak and strong coupling and can be useful for analysis of coupled betatron motion… more
Date: November 21, 2002
Creator: Bogacz, S. A. & Lebedev, V. A.
Partner: UNT Libraries Government Documents Department
open access

Measurements of diffractive processes at CDF

Description: We review the results of measurements on hard diffractive processes performed by the CDF Collaboration and report preliminary CDF results on two soft diffractive processes with a leading antiproton and a rapidity gap in addition to that associated with the antiproton. All results have been obtained from data collected in Run I of the Fermilab Tevatron {bar p}p collider.
Date: November 18, 2002
Creator: Goulianos, Konstantin
Partner: UNT Libraries Government Documents Department
open access

The new cosmology

Description: Over the past three years we have determined the basic features of our Universe. It is spatially flat; accelerating; comprised of 1/3 a new form of matter, 2/3 a new form of energy, with some ordinary matter and a dash of massive neutrinos; and it apparently began from a great burst of expansion during which quantum noise was stretched to astrophysical size seeding cosmic structure. This ''New Cosmology'' greatly extends the highly successful hot big-bang model. Now we have to make sense of it.… more
Date: November 19, 2002
Creator: Turner, Michael S.
Partner: UNT Libraries Government Documents Department
open access

Transport by Intermittency in the Boundary of the Diii-D Tokamak

Description: A271 TRANSPORT BY INTERMITTENCY IN THE BOUNDARY OF THE DIII-D TOKAMAK. Intermittent plasma objectives (IPOs) featuring higher pressure than the surrounding plasma, are responsible for {approx} 50% of the E x B{sub T} radial transport in the scrape off layer (SOL) of the DIII-D tokamak in L- and H-mode discharges. Conditional averaging reveals that the IPOs are positively charged and feature internal poloidal electric fields of up to 4000 V/m. The IPOs move radially with E x B{sub T}/B{sup 2} ve… more
Date: November 1, 2002
Creator: Boedo, J. A.; Rudakov, D. L.; Moyer, R. A.; Mckee, G. R.; Colchin, R. J.; Schaffer, M. J. et al.
Partner: UNT Libraries Government Documents Department
open access

Transport of Elm Energy and Particles Into the Sol and Divertor of DIII-D

Description: A271 TRANSPORT OF ELM ENERGY AND PARTICLES INTO THE SOL AND DIVERTOR OF DIII-D. The reduction in size of Type I edge localized models (ELMs) with increasing density is explored in DIII-D for the purpose of studying the underlying transport of ELM energy. The separate convective and conductive transport of energy due to an ELM is determined by Thomson scattering measurements of electron density and temperature in the pedestal. The conductive transport from the pedestal during an ELM decreases wi… more
Date: November 1, 2002
Creator: Leonard, A. W.; Osborne,T. H.; Fenstermacher, M. E.; Groebner, R. J.; Groth, M.; Lasnier, C. J. et al.
Partner: UNT Libraries Government Documents Department
open access

Demonstration in the DIII-D Tokamak of an Alternate Baseline Scenario for ITER and Other Burning Plasma Experiments

Description: OAK A271 DEMONSTRATION IN THE DIII-D TOKAMAK OF AN ALTERNATE BASELINE SCENARIO FOR ITER AND OTHER BURNING PLASMA EXPERIMENTS. Discharges which can satisfy the high gain goals of burning plasma experiments have been demonstrated in the DIII-D tokamak in stationary conditions with relatively low plasma current (q{sub 95} > 4). A figure of merit for fusion gain {Beta}{sub N}H{sub 89}/q{sub 95}{sup 2} has been maintained at values corresponding to Q = 10 operation in a burning plasma for > 6 … more
Date: November 1, 2002
Creator: Luce, T. C.; Wade, M. R.; Ferron, J. R.; Hyatt, A. W.; Kellman, A. G.; Kinsey, J. E. et al.
Partner: UNT Libraries Government Documents Department
open access

Condition for production of circulating proton beam with intensity greater than space charge limit.

Description: Transverse e-p instability in proton rings could be damped by increasing the beam density and the rate of secondary particles production above the threshold level, with the corresponding decrease of unstable wavelength {lambda} below the transverse beam size h (increase of beam density n{sub b} and ion density n{sub i} above the threshold level: n{sub b} + n{sub i} > {beta}{sup 2}/(r{sub e} h{sup 2}), where r{sub e} = e{sup 2}/mc{sup 2}). Such island of stability can be reached by a fast cha… more
Date: November 19, 2002
Creator: Dudnikov, Vadim
Partner: UNT Libraries Government Documents Department
open access

Positron Emission Mammography with Multiple Angle Acquisition

Description: Positron emission mammography (PEM) of F-18 fluorodeoxyglucose (FDG) uptake in breast tumors with dedicated detectors typically has been accomplished with two planar detectors in a fixed position with the breast under compression. The potential use of PEM imaging at two detector positions to guide stereotactic breast biopsy has motivated us to use PEM coincidence data acquired at two or more detector positions together in a single image reconstruction. Multiple angle PEM acquisition and iterati… more
Date: November 1, 2002
Creator: Smith, Mark F.; Majewski, Stan & Raylman, Raymond R.
Partner: UNT Libraries Government Documents Department
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