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Nonuniformity for rotated beam illumination in directly driven heavy-ion fusion

Description: A key issue in heavy-ion beam inertial confinement fusion is target interaction, especially implosion symmetry. In this paper the 2D beam irradiation nonuniformity on the surface of a spherical target is studied. This is a first step to studies of 3D dynamical effects on target implosion. So far non-rotated beams have been studied. Because normal incidence may increase Rayleigh-Taylor instabilities, it has been suggested to rotate beams (to increase average uniformity) and hit the target tangentially. The level of beam irradiation uniformity, beam spill and normal incidence is calculated in this paper. In Mathematica the rotated beams are modeled as an annular integrated Gaussian beam. To simplify the chamber geometry, the illumination scheme is not a 4{pi} system, but the beams are arranged on few polar rings around the target. The position of the beam spot rings is efficiently optimized using the analytical model. The number of rings and beams, rotation radii and widths are studied to optimize uniformity and spilled intensity. The results demonstrate that for a 60-beam system on four rings Peak-To-Valley nonuniformities of under 0.5% are possible.
Date: January 2, 2009
Creator: Runge, J. & Logan, B.G.
Partner: UNT Libraries Government Documents Department

IFC BIM-Based Methodology for Semi-Automated Building Energy Performance Simulation

Description: Building energy performance (BEP) simulation is still rarely used in building design, commissioning and operations. The process is too costly and too labor intensive, and it takes too long to deliver results. Its quantitative results are not reproducible due to arbitrary decisions and assumptions made in simulation model definition, and can be trusted only under special circumstances. A methodology to semi-automate BEP simulation preparation and execution makes this process much more effective. It incorporates principles of information science and aims to eliminate inappropriate human intervention that results in subjective and arbitrary decisions. This is achieved by automating every part of the BEP modeling and simulation process that can be automated, by relying on data from original sources, and by making any necessary data transformation rule-based and automated. This paper describes the new methodology and its relationship to IFC-based BIM and software interoperability. It identifies five steps that are critical to its implementation, and shows what part of the methodology can be applied today. The paper concludes with a discussion of application to simulation with EnergyPlus, and describes data transformation rules embedded in the new Geometry Simplification Tool (GST).
Date: July 1, 2008
Creator: Bazjanac, Vladimir
Partner: UNT Libraries Government Documents Department

Design of HD2: a 15 T Nb3Sn dipole with a 35 mm bore

Description: The Nb{sub 3}Sn dipole HD1, recently fabricated and tested at LBNL, pushes the limits of accelerator magnet technology into the 16 T field range, and opens the way to a new generation of HEP colliders. HD1 is based on a flat racetrack coil configuration and has a 10 mm bore. These features are consistent with the HD1 goals: exploring the Nb{sub 3}Sn conductor performance limits at the maximum fields and under high stress. However, in order to further develop the block-coil geometry for future high-field accelerators, the bore size has to be increased to 30-50 mm. With respect to HD1, the main R&D challenges are: (a) design of the coil ends, to allow a magnetically efficient cross-section without obstructing the beam path; (b) design of the bore, to support the coil against the pre-load force; (c) correction of the geometric field errors. HD2 represents a first step in addressing these issues, with a central dipole field above 15 T, a 35 mm bore, and nominal field harmonics within a fraction of one unit. This paper describes the HD2 magnet design concept and its main features, as well as further steps required to develop a cost-effective block-coil design for future high-field, accelerator-quality dipoles.
Date: June 1, 2005
Creator: Sabbi, G.; Bartlett, S. E.; Caspi, S.; Dietderich, D. R.; Ferracin, P.; Gourlay, S. A. et al.
Partner: UNT Libraries Government Documents Department

A High-Resolution Godunov Method for Compressible Multi-Material Flow on Overlapping Grids

Description: A numerical method is described for inviscid, compressible, multi-material flow in two space dimensions. The flow is governed by the multi-material Euler equations with a general mixture equation of state. Composite overlapping grids are used to handle complex flow geometry and block-structured adaptive mesh refinement (AMR) is used to locally increase grid resolution near shocks and material interfaces. The discretization of the governing equations is based on a high-resolution Godunov method, but includes an energy correction designed to suppress numerical errors that develop near a material interface for standard, conservative shock-capturing schemes. The energy correction is constructed based on a uniform pressure-velocity flow and is significant only near the captured interface. A variety of two-material flows are presented to verify the accuracy of the numerical approach and to illustrate its use. These flows assume an equation of state for the mixture based on Jones-Wilkins-Lee (JWL) forms for the components. This equation of state includes a mixture of ideal gases as a special case. Flow problems considered include unsteady one-dimensional shock-interface collision, steady interaction of an planar interface and an oblique shock, planar shock interaction with a collection of gas-filled cylindrical inhomogeneities, and the impulsive motion of the two-component mixture in a rigid cylindrical vessel.
Date: February 13, 2006
Creator: Banks, J W; Schwendeman, D W; Kapila, A K & Henshaw, W D
Partner: UNT Libraries Government Documents Department

Multi-Grained Level of Detail for Rendering Complex Meshes Using a Hierarchical Seamless Texture Atlas

Description: Previous algorithms for view-dependent level of detail provide local mesh refinements either at the finest granularity or at a fixed, coarse granularity. The former provides triangle-level adaptation, often at the expense of heavy CPU usage and low triangle rendering throughput; the latter improves CPU usage and rendering throughput by operating on groups of triangles. We present a new multiresolution hierarchy and associated algorithms that provide adaptive granularity. This multi-grained hierarchy allows independent control of the number of hierarchy nodes processed on the CPU and the number of triangles to be rendered on the GPU. We employ a seamless texture atlas style of geometry image as a GPU-friendly data organization, enabling efficient rendering and GPU-based stitching of patch borders. We demonstrate our approach on both large triangle meshes and terrains with up to billions of vertices.
Date: November 6, 2006
Creator: Niski, K; Purnomo, B & Cohen, J
Partner: UNT Libraries Government Documents Department

Final Report for the grant "Applied Geometry" (DOE DE-FG02-04ER25657)

Description: The primary purpose of this 3-year DOE-funded research effort, now completed, was to develop consistent, theoretical foundations of computations on discrete geometry, to realize the promise of predictive and scalable management of large geometric datasets as handled routinely in applied sciences. Geometry (be it simple 3D shapes or higher dimensional manifolds) is indeed a central and challenging issue from the modeling and computational perspective in several sciences such as mechanics, biology, molecular dynamics, geophysics, as well as engineering. From digital maps of our world, virtual car crash simulation, predictive animation of carbon nano-tubes, to trajectory design of space missions, knowing how to process and animate digital geometry is key in many cross-disciplinary research areas.
Date: May 20, 2009
Creator: Desbrun, Prof. Mathieu
Partner: UNT Libraries Government Documents Department

Minimizing emittance growth during H- injection in the AGS booster

Description: As part of the efforts to increase polarization and luminosity in RHIC during polarized proton operations we have modified the injection optics and stripping foil geometry in the AGS Booster in order to reduce the emittance growth during H{sup -} injection. In this paper we describe the modifications, the injection process, and present results from beam experiments.
Date: May 4, 2009
Creator: Brown,K.A.; Ahrens, L.; Gardner, C.; Gassner, D.; Raparia, D.; Steski, D. et al.
Partner: UNT Libraries Government Documents Department


Description: Formulas are derived for the equilibrium orbit, isochronous condition, vertical and horizontal betatron frequencies, and for the effects of the 3/3 radial resonance in a three-fold geometry. The magnetic field is represented by a Fourier series in azimuth with amplitudes expanded in a Taylor series about the reference radius. The form is such that the various parameters may be deduced from an arbitrary set of field measurements in the median plane and the results obtained by direct substitution in algebraic formulas.
Date: January 12, 1959
Creator: Smith, Lloyd & Garren, Alper A.
Partner: UNT Libraries Government Documents Department

Inspection 13.2 nm table-top full-field microscope

Description: We present results on a table-top microscope that uses an EUV stepper geometry to capture full-field images with a halfpitch spatial resolution of 55 nm. This microscope uses a 13.2 nm wavelength table-top laser for illumination and acquires images of reflective masks with exposures of 20 seconds. These experiments open the path to the realization of high resolution table-top imaging systems for actinic defect characterization.
Date: February 23, 2009
Creator: Brizuela, F.; Wang, Y.; Brewer, C. A.; Pedaci, F.; Chao, W.; Anderson, E. H. et al.
Partner: UNT Libraries Government Documents Department

Field Quality Optimization in a Common Coil Magnet Design

Description: This paper presents the results of initial field quality optimization of body and end harmonics in a 'common coil magnet design'. It is shown that a good field quality, as required in accelerator magnets, can be obtained by distributing conductor blocks in such a way that they simulate an elliptical coil geometry. This strategy assures that the amount of conductor used in this block design is similar to that is used in a conventional cosine theta design. An optimized yoke that keeps all harmonics small over the entire range of operation using a single power supply is also presented. The field harmonics are primarily optimized with the computer program ROXIE.
Date: September 1, 1999
Creator: Gupta, Ramesh & Ramberger, Suitbert
Partner: UNT Libraries Government Documents Department

San Juan single-well seismic data analysis and modeling study

Description: The authors analyze single-well seismic data from the San Juan basin in Northwest New Mexico. The consistently observable events are tube-waves: direct, reflected and multiple tube-waves can be explained by the formation properties and survey geometry except for an anomalous zone with low velocity, high amplitude and horizontal polarization. To aid the data analysis, forward modeling using a variable-grid finite-difference parallel code is performed. The numerical result confirms the identified events in the field observations.
Date: February 26, 2004
Creator: Daley, Tom; Wu, C.; Harris, J.M.; Daley, T.M. & Majer, E.L.
Partner: UNT Libraries Government Documents Department

Final Report: Geometry and Elementary Particle Physics

Description: The effect on mathematics of collaborations between high-energy theoretical physics and modern mathematics has been remarkable. Mirror symmetry has revolutionized enumerative geometry, and Seiberg-Witten invariants have greatly simplified the study of four manifolds. And because of their application to string theory, physicists now need to know cohomology theory, characteristic classes, index theory, K-theory, algebraic geometry, differential geometry, and non-commutative geometry. Much more is coming. We are experiencing a deeper contact between the two sciences, which will stimulate new mathematics essential to the physicists’ quest for the unification of quantum mechanics and relativity. Our grant, supported by the Department of Energy for twelve years, has been instrumental in promoting an effective interaction between geometry and string theory, by supporting the Mathematical Physics seminar, postdoc research, collaborations, graduate students and several research papers.
Date: March 4, 2008
Creator: Singer, Isadore M.
Partner: UNT Libraries Government Documents Department

TART 2000: A Coupled Neutron-Photon, 3-D, Combinatorial Geometry, Time Dependent, Monte Carlo Transport Code

Description: TART2000 is a coupled neutron-photon, 3 Dimensional, combinatorial geometry, time dependent Monte Carlo radiation transport code. This code can run on any modern computer. It is a complete system to assist you with input Preparation, running Monte Carlo calculations, and analysis of output results. TART2000 is also incredibly FAST; if you have used similar codes, you will be amazed at how fast this code is compared to other similar codes. Use of the entire system can save you a great deal of time and energy. TART2000 is distributed on CD. This CD contains on-line documentation for all codes included in the system, the codes configured to run on a variety of computers, and many example problems that you can use to familiarize yourself with the system. TART2000 completely supersedes all older versions of TART, and it is strongly recommended that users only use the most recent version of TART2000 and its data files.
Date: November 22, 2000
Creator: Cullen, D.E
Partner: UNT Libraries Government Documents Department

Modeling and Analysis of the Ranchero Coaxial Explosive Pulse Power Generator System

Description: A key element in the design of a coaxial generator system is the simplicity of the geometry. The clean cylindrical geometry allows us a reasonable chance at modeling RANCHERO performance using our 1D and 2D MHD modeling codes. The results of numerical simulations have been compare to several tests of the RANCHERO system in a variety of configurations. Recent comparisons of 1D calculations with the REOT-2 data have been extremely good and suggest that the generator is behaving in a very 1D like nature until reaching 90-95% of peak current. Differences between calculated current and measured performance during the last 3 mm (out of 70 mm) of flux compression may be a consequence of either the EOS for SF{sub 6}, 2D effects, or both. This study will examine the existing models and attempt to provide a robust integrated model which can then be used to drive design studies, pre- and post-shot analysis, and predict performance parameters for slight variations of the base design of RANCHE RO.
Date: June 28, 1999
Creator: Atchison, W.L.; Goforth, J.H.; Lindemuth, I.R. & Reinovsky, R.E.
Partner: UNT Libraries Government Documents Department

Programmed Assembly of Quantum-Dot Arrays on DNA Templates: Hardware for Quantum Computing?

Description: This paper reports progress in the fabrication and characterization of an array of 1nm-scale colloidal particles (i.e., quantum-dot array) that can be operated to execute nontrivial and innovative computations, possibly including quantum logic. We discuss the actual fabrication of 2-nm metal clusters as an example of possible quantum dot implementation. Innovative and unconventional paradigms underlie the different stages of this work. For example, regular array geometry is achieved by directing appropriately derivatized metal clusters to preselected locations along a stretched strand of an engineered DNA sequence.
Date: March 23, 2001
Creator: Wells, J.C.
Partner: UNT Libraries Government Documents Department


Description: The capability to plot superimposed meshes has been added to MCNP{trademark}. MCNP4C featured a superimposed mesh weight window generator which enabled users to set up geometries without having to subdivide geometric cells for variance reduction. The variance reduction was performed with weight windows on a rectangular or cylindrical mesh superimposed over the physical geometry. Experience with the new capability was favorable but also indicated that a number of enhancements would be very beneficial, particularly a means of visualizing the mesh and its values. The mathematics for plotting the mesh and its values is described here along with a description of other upgrades.
Date: February 1, 2001
Creator: HENDRICKS, J.
Partner: UNT Libraries Government Documents Department

Adjustable cutting tool holder

Description: This patent application describes a device for varying the geometry of a cutting tool for use in machining operations.
Date: September 21, 2000
Creator: Steinhour, William Lee III; West, Drew; Honeycutt, Steve; Frank, Steven & Krishnamurthy, Kallutla
Partner: UNT Libraries Government Documents Department

Rayleigh-taylor instability growth experiments in a cylindrically convergent geometry

Description: Convergent geometry Rayleigh-Taylor experiments have been performed with a 122-point detonation initiation system on cylinders having sinusoidal perturbations on the outer surface ranging from mode-6 to mode-36. Experiments were performed with various perturbation mode numbers, perturbation amplitudes, and ring accelerations. Feedthrough perturbation growth on the inner surface was observed in several experiments, and in one experiment the feed through perturbation underwent a phase inversion. These experimental results were found to be in good agreement with linear, small-amplitude analysis of feedthrough growth in an incompressible, cylindrically convergent geometry.
Date: June 11, 1997
Creator: Weir, S. T., LLNL
Partner: UNT Libraries Government Documents Department

March 1999 working group meeting on heavy vehicle aerodynamic drag: presentations and summary of comments and conclusions

Description: A Working Group Meeting on Heavy Vehicle Aerodynamic Drag was held at Lawrence Livermore National Laboratory, Livermore, California on March 11, 1999. The purpose of the meeting was to present technical details on the experimental and computational plans and approaches and provide an update on progress in obtaining experimental results, model developments, and simulations. The focus of the meeting was a review of the experimental results for the integrated tractor-trailer benchmark geometry called the Sandia Model in the NASA Ames 7 ft x 10 ft wind tunnel. The present and projected budget and funding situation was also discussed. Presentations were given by representatives from the Department of Energy (DOE) Office of Transportation Technology Office of Heavy Vehicle Technology (OHVT), Lawrence Livermore National Laboratory (LLNL), Sandia National Laboratories (SNL), University of Southern California (USC), California Institute of Technology (Caltech), and NASA Ames Research Center.This report contains the technical presentations (viewgraphs) delivered at the Meeting, briefly summarizes the comments and conclusions, and outlines the future action items.
Date: March 1999
Creator: Brady, M.; Browand, F.; McCallen, R.; Ross, J. & Salari, K.
Partner: UNT Libraries Government Documents Department