Development of tools and techniques for momentum compression of fast rare isotopes (open access)

Development of tools and techniques for momentum compression of fast rare isotopes

As part of our past research and development work, we have created and developed the LISE++ simulation code [Tar04, Tar08]. The LISE++ package was significantly extended with the addition of a Monte Carlo option that includes an option for calculating ion trajectories using a Taylor-series expansion up to fifth order, and implementation of the MOTER Monte Carlo code [Kow87] for ray tracing of the ions into the suite of LISE++ codes. The MOTER code was rewritten from FORTRAN into C++ and transported to the MS-Windows operating system. Extensive work went into the creation of a user-friendly interface for the code. An example of the graphical user interface created for the MOTER code is shown in the left panel of Figure 1 and the results of a typical calculation for the trajectories of particles that pass through the A1900 fragment separator are shown in the right panel. The MOTER code is presently included as part of the LISE++ package for downloading without restriction by the worldwide community. The LISE++ was extensively developed and generalized to apply to any projectile fragment separator during the early phase of this grant. In addition to the inclusion of the MOTER code, other important additions to …
Date: November 21, 2010
Creator: Morrissey, David J.; Sherrill, Bradley M. & Tarasov, Oleg
Object Type: Report
System: The UNT Digital Library
Target Visualization at the National Ignition Facility (open access)

Target Visualization at the National Ignition Facility

As the National Ignition Facility continues its campaign to achieve ignition, new methods and tools will be required to measure the quality of the targets used to achieve this goal. Techniques have been developed to measure target surface features using a phase-shifting diffraction interferometer and Leica Microsystems confocal microscope. Using these techniques we are able to produce a detailed view of the shell surface, which in turn allows us to refine target manufacturing and cleaning processes. However, the volume of data produced limits the methods by which this data can be effectively viewed by a user. This paper introduces an image-based visualization system for data exploration of target shells at the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory. It aims to combine multiple image sets into a single visualization to provide a method of navigating the data in ways that are not possible with existing tools.
Date: November 21, 2011
Creator: Potter, D
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Solid Collection Efforts: Ta Collimator Evaluation (open access)

Solid Collection Efforts: Ta Collimator Evaluation

Ta collimator sets that were part of the gated x-ray detector diagnostic (GXD) at NIF were analyzed for debris distribution and damage in 2011. These disks (ranging in thickness from 250 to 750 {mu}m) were fielded approximately 10 cm from target chamber center (TCC) on various symcap, THD and re-emit shots. The nose cone holder and forward Ta collimator (facing target chamber center, TCC) from all shots show evidence of surface melt. Non-destructive analysis techniques such as optical microscopy, surface profilometry, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and x-ray fluorescence (XRF) were used to determine debris composition and degree of deformation associated with each Ta disk. Molten debris from the stainless steel nose cone contaminated the surface of the collimators along with other debris associated with the target assembly (Al, Si, Cu, Au and In). Surface elemental analysis of the forward collimator Ta disks indicates that Au hohlraum debris is less concentrated on these samples versus those fielded 50 cm from TCC in the wedge range filter (WRF) assembly. It is possible that the Au is distributed below or within the stainless steel melt layer covering the disk, as most of the foreign debris is captured in the …
Date: November 21, 2011
Creator: Gostic, J M
Object Type: Report
System: The UNT Digital Library
Energy Savings and Green Initiatives Project Grant (open access)

Energy Savings and Green Initiatives Project Grant

This project entails retrofitting all four foot, 2, 3 and 4 bulb 40 watt T12 fixtures to T8 28 watt and 150 watt incandescent to 26 watt compact fluorescent bulbs. In total, 2,086 fixtures will be retrofitted
Date: November 21, 2011
Creator: MacLennan, Kathy
Object Type: Report
System: The UNT Digital Library
GROUNDWATER MONITORING REPORT GENERATION TOOLS - 12005 (open access)

GROUNDWATER MONITORING REPORT GENERATION TOOLS - 12005

Compliance with National and State environmental regulations (e.g. Resource Conservation and Recovery Act (RCRA) and Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) aka SuperFund) requires Savannah River Site (SRS) to extensively collect and report groundwater monitoring data, with potential fines for missed reporting deadlines. Several utilities have been developed at SRS to facilitate production of the regulatory reports which include maps, data tables, charts and statistics. Components of each report are generated in accordance with complex sets of regulatory requirements specific to each site monitored. SRS developed a relational database to incorporate the detailed reporting rules with the groundwater data, and created a set of automation tools to interface with the information and generate the report components. These process improvements enhanced quality and consistency by centralizing the information, and have reduced manpower and production time through automated efficiencies.
Date: November 21, 2011
Creator: Lopez, N.
Object Type: Article
System: The UNT Digital Library
Summary of Blast Shield and Material Testing for Development of Solid Debris Collection at the National Ignition Facility (NIF) (open access)

Summary of Blast Shield and Material Testing for Development of Solid Debris Collection at the National Ignition Facility (NIF)

The ability to collect solid debris from the target chamber following a NIF shot has application for both capsule diagnostics, particularly for fuel-ablator mix, and measuring cross sections relevant to the Stockpile Stewardship program and nuclear astrophysics. Simulations have shown that doping the capsule with up to 10{sup 15} atoms of an impurity not otherwise found in the capsule does not affect its performance. The dopant is an element that will undergo nuclear activations during the NIF implosion, forming radioactive species that can be collected and measured after extraction from the target chamber. For diagnostics, deuteron or alpha induced reactions can be used to probe the fuel-ablator mix. For measuring neutron cross sections, the dopant should be something that is sensitive to the 14 MeV neutrons produced through the fusion of deuterium and tritium. Developing the collector is a challenge due to the extreme environment of the NIF chamber. The collector surface is exposed to a large photon flux from x-rays and unconverted laser light before it is exposed to a debris wind that is formed from vaporized material from the target chamber center. The photons will ablate the collector surface to some extent, possibly impeding the debris from reaching …
Date: November 21, 2011
Creator: Shaughnessy, D A; Gostic, J M; Moody, K J; Grant, P M; Lewis, L A & Hutcheon, I D
Object Type: Report
System: The UNT Digital Library
Particle Physics Outreach to Secondary Education (open access)

Particle Physics Outreach to Secondary Education

This review summarizes exemplary secondary education and outreach programs of the particle physics community. We examine programs from the following areas: research experiences, high-energy physics data for students, informal learning for students, instructional resources, and professional development. We report findings about these programs' impact on students and teachers and provide suggestions for practices that create effective programs from those findings. We also include some methods for assessing programs.
Date: November 21, 2011
Creator: Bardeen, Marjorie G.; Johansson, K. Erik & Young, M. Jean
Object Type: Article
System: The UNT Digital Library
Scrape-Off-Layer Flow Studies in Tokamaks: Final Report of LDRD Project 09-ERD-025 (open access)

Scrape-Off-Layer Flow Studies in Tokamaks: Final Report of LDRD Project 09-ERD-025

A summary is given of the work carried out under the LDRD project 09-ERD-025 entitled Scrape-Off-Layer Flow Studies in Tokamaks. This project has lead to implementation of the new prototype Fourier Transform Spectrometer edge plasma flow diagnostic on the DIII-D National Fusion Facility at General Atomics, acquisition of carbon impurity concentration and flow data, and demonstration that the resulting data compare reasonably well with LLNL's edge plasma transport code UEDGE. Details of the work are contained in attached published papers, while the most recent results that are being written-up for publication are summarized in the report. Boundary plasma flows in tokamak fusion devices are key in determining the distribution of fuel and impurity ions, with tritium build-up in the walls an especially critical operational issue. The intrusion of impurity ions to the hot plasma core region can result in serious energy-loss owing to line radiation. However, flow diagnostic capability has been severely limited in fusion-relevant hot edge plasmas where Langmuir-type probes cannot withstand the high heat flux and traditional Doppler spectroscopy has limited resolution and signal strength. Thus, new edge plasma flow diagnostic capabilities need to be developed that can be used in existing and future devices such as ITER. …
Date: November 21, 2011
Creator: Rognlien, T. D.; Allen, S. L.; Ellis, R. M.; Porter, G. D.; Nam, S. K.; Weber, T. R. et al.
Object Type: Report
System: The UNT Digital Library
Longitudinal Beam Tuning at FACET (open access)

Longitudinal Beam Tuning at FACET

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Date: November 21, 2012
Creator: Decker, F.-J.; Lipkowitz, N.; Sheppard, J.; Weathersby, S.P.; Wienands, U.; Woodley, M. et al.
Object Type: Article
System: The UNT Digital Library
Scientific/Technical Report (open access)

Scientific/Technical Report

This symposium aimed to bring together researchers working on quantifying nanoscale carrier transport processes in excitonic solar cells. Excitonic solar cells, including all-organic, hybrid organic-inorganic and dye-sensitized solar cells (DSSCs), offer strong potential for inexpensive and large-area solar energy conversion. Unlike traditional inorganic semiconductor solar cells, where all the charge generation and collection processes are well understood, these excitonic solar cells contain extremely disordered structures with complex interfaces which results in large variations in nanoscale electronic properties and has a strong influence on carrier generation, transport, dissociation and collection. Detailed understanding of these processes is important for fabrication of highly efficient solar cells. Efforts to improve efficiency are underway at a large number of research groups throughout the world focused on inorganic and organic semiconductors, photonics, photophysics, charge transport, nanoscience, ultrafast spectroscopy, photonics, semiconductor processing, device physics, device structures, interface structure etc. Rapid progress in this multidisciplinary area requires strong synergetic efforts among researchers from diverse backgrounds. Such efforts can lead to novel methods for development of new materials with improved photon harvesting and interfacial treatments for improved carrier transport, process optimization to yield ordered nanoscale morphologies with well-defined electronic structures.
Date: November 21, 2012
Creator: Bommissetty, Venkat
Object Type: Report
System: The UNT Digital Library
Divertor Scenario Development for NSTX Upgrade (open access)

Divertor Scenario Development for NSTX Upgrade

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Date: November 21, 2012
Creator: Soukhanovskii, V A
Object Type: Article
System: The UNT Digital Library
Enhanced photoluminescence in plasmonic resonant nanocavities (open access)

Enhanced photoluminescence in plasmonic resonant nanocavities

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Date: November 21, 2012
Creator: Munechika, K.; Bond, T.; Bora, M.; Chang, A. S.; Behymer, E. M.; Dehlinger, D. A. et al.
Object Type: Article
System: The UNT Digital Library
FACET First Beam Commissioning (open access)

FACET First Beam Commissioning

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Date: November 21, 2012
Creator: Clarke, C. I.; Colocho, W. S.; Decker, F. J.; Hogan, M. J.; Lipkowitz, N.; Nelson, J. et al.
Object Type: Article
System: The UNT Digital Library
Research and Development of Non-Spectroscopic MEMS-Based Sensor Arrays for Targeted Gas Detection (open access)

Research and Development of Non-Spectroscopic MEMS-Based Sensor Arrays for Targeted Gas Detection

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Date: November 21, 2012
Creator: Loui, A; McCall, S K & Zumstein, J M
Object Type: Report
System: The UNT Digital Library
Experiment to Detect Accelerating Modes in a Photonic Bandgap Fiber (open access)

Experiment to Detect Accelerating Modes in a Photonic Bandgap Fiber

An experimental effort is currently underway at the E-163 test beamline at Stanford Linear Accelerator Center to use a hollow-core photonic bandgap (PBG) fiber as a high-gradient laser-based accelerating structure for electron bunches. For the initial stage of this experiment, a 50pC, 60 MeV electron beam will be coupled into the fiber core and the excited modes will be detected using a spectrograph to resolve their frequency signatures in the wakefield radiation generated by the beam. They will describe the experimental plan and recent simulation studies of candidate fibers.
Date: November 21, 2011
Creator: England, R.J.; /SLAC; Colby, E.R.; /SLAC; Ischebeck, R.; /Munich, Max Planck Inst. Quantenopt. et al.
Object Type: Article
System: The UNT Digital Library
Quarkonium States at B-Factories (open access)

Quarkonium States at B-Factories

An overview is given on recent progress in the study of quarkonium spectroscopy at the B-factories. In particular, an updated status report is presented of the long list of 'charmonium-like' resonances newly discovered, whose assignment as true charmonium states is in most cases at least controversial. Also, new measurements on the decay properties of bottomonium states above open-B production thresholds are shown. Much of the progress attained in recent years in the study of the quarkonium spectra is owed to the measurements performed at B-factories. The impressive amount of data recorded by the BABAR and Belle experiments has made it possible to study rare decay chains and to look for as yet undiscovered resonances in the charmonium and bottomonium mass regions. Results presented here are based on different subsamples of the full datasets recorded up to now by the two experiments, corresponding to integrated luminosities of about 430 fb{sup -1}(BABAR - final) and about 850 fb{sup -1}(Belle). Significant contributions also come from the analysis of the various data samples recorded by the CLEO detector.
Date: November 21, 2011
Creator: Robutti, Enrico & /INFN, Genoa
Object Type: Article
System: The UNT Digital Library
Speed Limit of the Insulator - Metal Transition in Magnetite (open access)

Speed Limit of the Insulator - Metal Transition in Magnetite

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Date: November 21, 2013
Creator: de Jong, S; Kukreja, R.; Trabant, C.; Pontius, N.; Chang, C. F.; Kachel, T. et al.
Object Type: Article
System: The UNT Digital Library
Wolfgang K.H. Panofsky: Scientist and Arms-Control Expert (open access)

Wolfgang K.H. Panofsky: Scientist and Arms-Control Expert

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Date: November 21, 2013
Creator: Luth, Vera
Object Type: Article
System: The UNT Digital Library
New Design Methods And Algorithms For High Energy-Efficient And Low-cost Distillation Processes (open access)

New Design Methods And Algorithms For High Energy-Efficient And Low-cost Distillation Processes

This project sought and successfully answered two big challenges facing the creation of low-energy, cost-effective, zeotropic multi-component distillation processes: first, identification of an efficient search space that includes all the useful distillation configurations and no undesired configurations; second, development of an algorithm to search the space efficiently and generate an array of low-energy options for industrial multi-component mixtures. Such mixtures are found in large-scale chemical and petroleum plants. Commercialization of our results was addressed by building a user interface allowing practical application of our methods for industrial problems by anyone with basic knowledge of distillation for a given problem. We also provided our algorithm to a major U.S. Chemical Company for use by the practitioners. The successful execution of this program has provided methods and algorithms at the disposal of process engineers to readily generate low-energy solutions for a large class of multicomponent distillation problems in a typical chemical and petrochemical plant. In a petrochemical complex, the distillation trains within crude oil processing, hydrotreating units containing alkylation, isomerization, reformer, LPG (liquefied petroleum gas) and NGL (natural gas liquids) processing units can benefit from our results. Effluents from naphtha crackers and ethane-propane crackers typically contain mixtures of methane, ethylene, ethane, propylene, …
Date: November 21, 2013
Creator: Agrawal, Rakesh
Object Type: Report
System: The UNT Digital Library
Protective Measures Index and Vulnerability Index: Indicators of Critical Infrastructure Protection and Vulnerability (open access)

Protective Measures Index and Vulnerability Index: Indicators of Critical Infrastructure Protection and Vulnerability

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Date: November 21, 2013
Creator: Petit, F. D.; Bassett, G. W.; Buehring, W. A.; Collins, M. J.; Dickinson, D. C.; Haffenden, R. A. et al.
Object Type: Report
System: The UNT Digital Library
Isolation of Battery Chargers Integrated Into Printed Circuit Boards (open access)

Isolation of Battery Chargers Integrated Into Printed Circuit Boards

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Date: November 21, 2013
Creator: Sullivan, J S
Object Type: Report
System: The UNT Digital Library
Survey of Novel Programming Models for Parallelizing Applications at Exascale (open access)

Survey of Novel Programming Models for Parallelizing Applications at Exascale

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Date: November 21, 2011
Creator: Cook, R.; Dube, E.; Lee, I.; Shereda, C.; Wang, F. & Nau, L.
Object Type: Report
System: The UNT Digital Library