Active Interrogation Using Electronic Neutron Generators for Nuclear Safeguards Applications (open access)

Active Interrogation Using Electronic Neutron Generators for Nuclear Safeguards Applications

Active interrogation, a measurement technique which uses a radiation source to probe materials and generate unique signatures useful for characterizing those materials, is a powerful tool for assaying special nuclear material. The most commonly used technique for performing active interrogation is to use an electronic neutron generator as the probe radiation source. Exploiting the unique operating characteristics of these devices, including their monoenergetic neutron emissions and their ability to operate in pulsed modes, presents a number of options for performing prompt and delayed signature analyses using both photon and neutron sensors. A review of literature in this area shows multiple applications of the active neutron interrogation technique for performing nuclear nonproliferation measurements. Some examples include measuring the plutonium content of spent fuel, assaying plutonium residue in spent fuel hull claddings, assaying plutonium in aqueous fuel reprocessing process streams, and assaying nuclear fuel reprocessing facility waste streams to detect and quantify fissile material. This paper discusses the historical use of this technique and examines its context within the scope and challenges of next-generation nuclear fuel cycles and advanced concept nuclear fuel cycle facilities.
Date: August 1, 2008
Creator: Chichester, David L. & Seabury, Edward H.
Object Type: Article
System: The UNT Digital Library
An Adaptive Landscape Classification Procedure using Geoinformatics and Artificial Neural Networks (open access)

An Adaptive Landscape Classification Procedure using Geoinformatics and Artificial Neural Networks

The Adaptive Landscape Classification Procedure (ALCP), which links the advanced geospatial analysis capabilities of Geographic Information Systems (GISs) and Artificial Neural Networks (ANNs) and particularly Self-Organizing Maps (SOMs), is proposed as a method for establishing and reducing complex data relationships. Its adaptive and evolutionary capability is evaluated for situations where varying types of data can be combined to address different prediction and/or management needs such as hydrologic response, water quality, aquatic habitat, groundwater recharge, land use, instrumentation placement, and forecast scenarios. The research presented here documents and presents favorable results of a procedure that aims to be a powerful and flexible spatial data classifier that fuses the strengths of geoinformatics and the intelligence of SOMs to provide data patterns and spatial information for environmental managers and researchers. This research shows how evaluation and analysis of spatial and/or temporal patterns in the landscape can provide insight into complex ecological, hydrological, climatic, and other natural and anthropogenic-influenced processes. Certainly, environmental management and research within heterogeneous watersheds provide challenges for consistent evaluation and understanding of system functions. For instance, watersheds over a range of scales are likely to exhibit varying levels of diversity in their characteristics of climate, hydrology, physiography, ecology, and anthropogenic …
Date: August 1, 2008
Creator: Coleman, Andre M.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Adsorption of water on O(2x2)/Ru(0001): thermal stability and inhibition of dissociation by H2O-O bonding (open access)

Adsorption of water on O(2x2)/Ru(0001): thermal stability and inhibition of dissociation by H2O-O bonding

The effect of preadsorbed oxygen on the subsequent adsorption and reactions of water on Ru(0001) has been studied using low temperature scanning tunneling microscopy and DFT calculations. Experiments were carried out for O coverages close to 0.25 ML. It was found that no dissociation of water takes place up to the desorption temperature of {approx}180-230 K. DFT calculations show that intact water on O(2x2)/Ru(0001) is {approx} 0.49 eV more stable than the dissociation products, H and OH, at their preferred fcc and top adsorption sites.
Date: August 1, 2008
Creator: Mugarza, Aitor; Shimizu, Tomoko; Cabrera-Sanfelix, Pepa; Sanchez-Portal, Daniel; Arnau, Andres & Salmeron, Miquel
Object Type: Article
System: The UNT Digital Library
Advanced, High-Reliability, System-Integrated 500kW PV Inverter Development: Final Subcontract Report, 29 September 2005 - 31 May 2008 (open access)

Advanced, High-Reliability, System-Integrated 500kW PV Inverter Development: Final Subcontract Report, 29 September 2005 - 31 May 2008

Xantrex Technology accomplished subcontract goals of reducing parts cost, weight, and size of its 500-kW inverter by 25% compared to state-of-the-art PV inverters, while extending reliability by 25%.
Date: August 1, 2008
Creator: West, R.
Object Type: Report
System: The UNT Digital Library
Advanced Vehicles Group: Center for Transportation Technologies and Systems (open access)

Advanced Vehicles Group: Center for Transportation Technologies and Systems

Describes R&D in advanced vehicle systems and components (e.g., batteries) by NREL's Advanced Vehicles Group.
Date: August 1, 2008
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Advancing the state of the art in materials accountancy through Safeguards Performance Modeling. (open access)

Advancing the state of the art in materials accountancy through Safeguards Performance Modeling.

None
Date: August 1, 2008
Creator: Ricker, Neil Lawrence (University of Washington, Seattle, WA) & Cipiti, Benjamin B.
Object Type: Report
System: The UNT Digital Library
Analysis of voltage spikes in superconducting Nb3Sn magnets (open access)

Analysis of voltage spikes in superconducting Nb3Sn magnets

Fermi National Accelerator Laboratory has been developing a new generation of superconducting accelerator magnets based on Niobium Tin (Nb{sub 3}Sn). The performance of these magnets is influenced by thermo-magnetic instabilities, known as flux jumps, which can lead to premature trips of the quench detection system due to large voltage transients or quenches at low current. In an effort to better characterize and understand these instabilities, a system for capturing fast voltage transients was developed and used in recent tests of R&D model magnets. A new automated voltage spike analysis program was developed for the analysis of large amount of voltage-spike data. We report results from the analysis of large statistics data samples for short model magnets that were constructed using MJR and RRP strands having different sub-element size and structure. We then assess the implications for quench protection of Nb{sub 3}Sn magnets.
Date: August 1, 2008
Creator: Rahimzadeh-Kalaleh, S.; Ambrosio, G.; Chlachidze, G.; Donnelly, C. & Tartaglia, M.
Object Type: Article
System: The UNT Digital Library
Analytical Method for the Detection of Ozone Depleting Chemicals (ODC) in Commercial Products Using a Gas Chromatograph with an Electron Capture Detector (GC-ECD) (open access)

Analytical Method for the Detection of Ozone Depleting Chemicals (ODC) in Commercial Products Using a Gas Chromatograph with an Electron Capture Detector (GC-ECD)

This document describes an analytical procedure that was developed for the trace level detection of residual ozone depleting chemicals (ODC) associated with the manufacture of selected commercial products. To ensure the United States meets it obligation under the Montreal Protocol, Congress enacted legislation in 1989 to impose an excise tax on electronic goods imported into the United States that were produced with banned chemicals. This procedure was developed to technically determine if residual ODC chemicals could be detected on electronic circuit boards. The analytical method utilizes a “purge and trap” technique followed by gas chromatography with electron capture detection to capture and analyze the volatile chemicals associated with the matrix. The method describes the procedure, the hardware, operating conditions, calibration, and quality control measures in sufficient detail to allow the capability to be replicated. This document corresponds to internal Standard Operating Procedure (SOP) EFL-130A, Rev 4.
Date: August 1, 2008
Creator: Lee, Richard N.; Dockendorff, Brian P. & Wright, Bob W.
Object Type: Report
System: The UNT Digital Library
Analytical models for total dose ionization effects in MOS devices. (open access)

Analytical models for total dose ionization effects in MOS devices.

MOS devices are susceptible to damage by ionizing radiation due to charge buildup in gate, field and SOI buried oxides. Under positive bias holes created in the gate oxide will transport to the Si / SiO{sub 2} interface creating oxide-trapped charge. As a result of hole transport and trapping, hydrogen is liberated in the oxide which can create interface-trapped charge. The trapped charge will affect the threshold voltage and degrade the channel mobility. Neutralization of oxidetrapped charge by electron tunneling from the silicon and by thermal emission can take place over long periods of time. Neutralization of interface-trapped charge is not observed at room temperature. Analytical models are developed that account for the principal effects of total dose in MOS devices under different gate bias. The intent is to obtain closed-form solutions that can be used in circuit simulation. Expressions are derived for the aging effects of very low dose rate radiation over long time periods.
Date: August 1, 2008
Creator: Campbell, Phillip Montgomery & Bogdan, Carolyn W.
Object Type: Report
System: The UNT Digital Library
Anisotropic Hexagonal Boron Nitride Nanomaterials - Synthesis and Applications (open access)

Anisotropic Hexagonal Boron Nitride Nanomaterials - Synthesis and Applications

Boron nitride (BN) is a synthetic binary compound located between III and V group elements in the Periodic Table. However, its properties, in terms of polymorphism and mechanical characteristics, are rather close to those of carbon compared with other III-V compounds, such as gallium nitride. BN crystallizes into a layered or a tetrahedrally linked structure, like those of graphite and diamond, respectively, depending on the conditions of its preparation, especially the pressure applied. Such correspondence between BN and carbon readily can be understood from their isoelectronic structures [1, 2]. On the other hand, in contrast to graphite, layered BN is transparent and is an insulator. This material has attracted great interest because, similar to carbon, it exists in various polymorphic forms exhibiting very different properties; however, these forms do not correspond strictly to those of carbon. Crystallographically, BN is classified into four polymorphic forms: Hexagonal BN (h-BN) (Figure 1(b)); rhombohedral BN (r-BN); cubic BN (c-BN); and wurtzite BN (w-BN). BN does not occur in nature. In 1842, Balmain [3] obtained BN as a reaction product between molten boric oxide and potassium cyanide under atmospheric pressure. Thereafter, many methods for its synthesis were reported. h-BN and r-BN are formed under ambient …
Date: August 1, 2008
Creator: Han,W.Q.
Object Type: Book
System: The UNT Digital Library
The Anti-B ---> D* l anti-nu form factor at zero recoil from three-flavor lattice QCD: A Model independent determination of |V(cb)| (open access)

The Anti-B ---> D* l anti-nu form factor at zero recoil from three-flavor lattice QCD: A Model independent determination of |V(cb)|

None
Date: August 1, 2008
Creator: Bernard, C.; DeTar, C.; Di Pierro, M.; El-Khadra, A. X.; Evans, R. T.; Freeland, E. D. et al.
Object Type: Article
System: The UNT Digital Library
Approaching 10% Conversion Efficiency Using Tandem Organic Photovoltaic Cells with Enhanced Optical Coupling: Final Report, October 2004 - December 2007 (open access)

Approaching 10% Conversion Efficiency Using Tandem Organic Photovoltaic Cells with Enhanced Optical Coupling: Final Report, October 2004 - December 2007

To find routes to achieving nearly 10% power conversion efficiency based on a new generation of organic photovoltaic cells using vapor-deposited, small-molecular-weight organic materials.
Date: August 1, 2008
Creator: Forrest, S.
Object Type: Report
System: The UNT Digital Library
An Atomic Gravitational Wave Interferometric Sensor (AGIS) (open access)

An Atomic Gravitational Wave Interferometric Sensor (AGIS)

We propose two distinct atom interferometer gravitational wave detectors, one terrestrial and another satellite-based, utilizing the core technology of the Stanford 10m atom interferometer presently under construction. Each configuration compares two widely separated atom interferometers run using common lasers. The signal scales with the distance between the interferometers, which can be large since only the light travels over this distance, not the atoms. The terrestrial experiment with baseline {approx} 1 km can operate with strain sensitivity {approx} 10{sup -19}/{radical}Hz in the 1 Hz-10 Hz band, inaccessible to LIGO, and can detect gravitational waves from solar mass binaries out to megaparsec distances. The satellite experiment with baseline {approx} 1000 km can probe the same frequency spectrum as LISA with comparable strain sensitivity {approx} 10{sup -20}/{radical}Hz. The use of ballistic atoms (instead of mirrors) as inertial test masses improves systematics coming from vibrations, acceleration noise, and significantly reduces spacecraft control requirements. We analyze the backgrounds in this configuration and discuss methods for controlling them to the required levels.
Date: August 1, 2008
Creator: Dimopoulos, Savas; Graham, Peter W.; Hogan, Jason M.; Kasevich, Mark A. & Rajendran, Surjeet
Object Type: Report
System: The UNT Digital Library
Beam instrumentation for future high intense hadron accelerators at Fermilab (open access)

Beam instrumentation for future high intense hadron accelerators at Fermilab

High intensity hadron beams of up to 2 MW beam power are a key element of new proposed experimental facilities at Fermilab. Project X, which includes a SCRF 8 GeV H{sup -} linac, will be the centerpiece of future HEP activities in the neutrino sector. After a short overview of this, and other proposed projects, we present the current status of the beam instrumentation activities at Fermilab with a few examples. With upgrades and improvements they can meet the requirements of the new beam facilities, however design and development of new instruments is needed, as shown by the prototype and conceptual examples in the last section.
Date: August 1, 2008
Creator: Wendt, M.; Hu, M.; Tassotto, G.; Thurman-Keup, R.; Scarpine, V.; Shin, S. et al.
Object Type: Article
System: The UNT Digital Library
A Bioinformatician's Guide to Metagenomics (open access)

A Bioinformatician's Guide to Metagenomics

As random shotgun metagenomic projects proliferate and become the dominant source of publicly available sequence data, procedures for best practices in their execution and analysis become increasingly important. Based on our experience at the Joint Genome Institute, we describe step-by-step the chain of decisions accompanying a metagenomic project from the viewpoint of a bioinformatician. We guide the reader through a standard workflow for a metagenomic project beginning with pre-sequencing considerations such as community composition and sequence data type that will greatly influence downstream analyses. We proceed with recommendations for sampling and data generation including sample and metadata collection, community profiling, construction of shotgun libraries and sequencing strategies. We then discuss the application of generic sequence processing steps (read preprocessing, assembly, and gene prediction and annotation) to metagenomic datasets by contrast to genome projects. Different types of data analyses particular to metagenomes are then presented including binning, dominant population analysis and gene-centric analysis. Finally data management systems and issues are presented and discussed. We hope that this review will assist bioinformaticians and biologists in making better-informed decisions on their journey during a metagenomic project.
Date: August 1, 2008
Creator: Kunin, Victor; Copeland, Alex; Lapidus, Alla; Mavromatis, Konstantinos & Hugenholtz, Philip
Object Type: Article
System: The UNT Digital Library
Capabilities of the INL ZPPR to Support Active Interrogation Research with SNM (open access)

Capabilities of the INL ZPPR to Support Active Interrogation Research with SNM

For over 40 years Idaho National Laboratory (INL) and its predecessor organizations have maintained and operated the Zero-Power Physics Reactor (ZPPR) as a test bed for studying reactor physics and nuclear reactor design. Although the ZPPR is no longer operated as an active research reactor, it’s infrastructure (radiation shielding, safety systems, physical safeguards) and special nuclear material (SNM) inventory (variably enriched uranium and plutonium fuels available in metallic, oxide, alloy, and other forms) still makes the facility a unique national resource for research and development activities involving the use of SNM. Recently INL has utilized this facility to serve as a test and evaluation facility for active interrogation research and development. This facility is currently hosting scoping experiments using neutron and x-ray radiation sources to characterize SNM active interrogation signatures and to develop tools and techniques to detect and identify shielded SNM. This paper presents an overview of the facility’s infrastructure and assets and describes recent active interrogation experiments that have taken place using high-energy x-ray sources and compact electronic neutron generators.
Date: August 1, 2008
Creator: Chichester, David L.; Seabury, Edward H.; Turnage, Jennifer A.; Brush, Bevin A. & Perry, Eugene F.
Object Type: Article
System: The UNT Digital Library
The CDF L2 Track Trigger Upgrade (open access)

The CDF L2 Track Trigger Upgrade

None
Date: August 1, 2008
Creator: Cox, David
Object Type: Article
System: The UNT Digital Library
Charon parallel semiconductor device simulator. (open access)

Charon parallel semiconductor device simulator.

None
Date: August 1, 2008
Creator: Lin, Paul Tinphone; Hennigan, Gary Lee; Castro, Joseph Pete, Jr. & Fixel, Deborah A.
Object Type: Report
System: The UNT Digital Library
Coaxial Mono-Energetic Gamma Generator for Active Interrogation (open access)

Coaxial Mono-Energetic Gamma Generator for Active Interrogation

Compact mono-energetic photon sources are sought for active interrogation systems to detect shielded special nuclear materials in, for example, cargo containers, trucks and other vehicles. A prototype gamma interrogation source has been designed and built that utilizes the 11B(p,gamma)12C reaction to produce 12 MeV gamma-rays which are near the peak of the photofission cross section. In particular, the 11B(p,gamma)12C resonance at 163 kV allows the production of gammas at low proton acceleration voltages, thus keeping the design of a gamma generator comparatively small and simple. A coaxial design has been adopted with a toroidal-shaped plasma chamber surrounding a cylindrical gamma production target. The plasma discharge is driven by a 2 MHz rf-power supply (capable up to 50 kW) using a circular rf-antenna. Permanent magnets embedded in the walls of the plasma chamber generate a multi-cusp field that confines the plasma and allows higher plasma densities and lower gas pressures. About 100 proton beamlets are extracted through a slotted plasma electrode towards the target at the center of the device that is at a negative 180 kV. The target consists of LaB6 tiles that are brazed to a water-cooled cylindrical structure. The generator is designed to operate at 500 Hz with …
Date: August 1, 2008
Creator: Ludewigt, Bernhard A.; Antolak, A. J.; Henestroza, E.; Leitner, M.; Leung, K. N.; Waldron, W. et al.
Object Type: Article
System: The UNT Digital Library
Combination of CDF and D0 results on the W boson mass and width (open access)

Combination of CDF and D0 results on the W boson mass and width

The results on the direct measurements of the W-boson mass and width, based on the data collected by the Tevatron experiments CDF and D{sup -} at Fermilab are summarized and combined. The CDF Run-0 (1988-1889) and Run-I (1992-1995) results have been re-averaged using the BLUE method and combined with Run-I D{sup -} results and the latest published results from CDF taken from the first period of Run-II (2001-2004). The results are corrected to have consistency between the parton distribution functions and electroweak parameters. The resulting Tevatron averages for the mass and total decay width of the W boson are: M{sub W} = 80432 {+-} 39 MeV and {Lambda}{sub W} = 2056 {+-} 62 MeV. The inclusion of a preliminary Run-II measurement of {Lambda}{sub W} from D{sup -}0 gives {Lambda}{sub W} = 2050 {+-} 58 MeV.
Date: August 1, 2008
Creator: Group, Tevatron Electroweak Working
Object Type: Report
System: The UNT Digital Library
Commissioning Ventilated Containment Systems in the Laboratory (open access)

Commissioning Ventilated Containment Systems in the Laboratory

This Best Practices Guide focuses on the specialized approaches required for ventilated containment systems, understood to be all components that drive and control ventilated enclosures and local exhaust systems within the laboratory. Geared toward architects, engineers, and facility managers, this guide provides information about technologies and practices to use in designing, constructing, and operating operating safe, sustainable, high-performance laboratories.
Date: August 1, 2008
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Compact IR Quadrupoles for Linear Colliders Based on Rutherford-type Cable (open access)

Compact IR Quadrupoles for Linear Colliders Based on Rutherford-type Cable

The upcoming and disrupted beams in the interaction region (IR) of a linear collider are focused by doublets consisting of two small-aperture superconducting quadrupoles. These magnets need an effective compact magnetic shielding to minimize magnetic coupling between the two channels and sufficient temperature margin to withstand radiation-induced heat depositions in the coil. This paper presents conceptual designs of IR quadrupoles for linear colliders based on NbTi and Nb{sub 3}Sn Rutherford-type cables.
Date: August 1, 2008
Creator: Lopes, M. L.; Kashikhin, V. S.; Kashikhin, V. V. & Zlobin, A. V.
Object Type: Article
System: The UNT Digital Library
A Comparison of Neutron-Based Non-Destructive Assessment Methods for Chemical Warfare Materiel and High Explosives (open access)

A Comparison of Neutron-Based Non-Destructive Assessment Methods for Chemical Warfare Materiel and High Explosives

Prompt Gamma Neutron Activation Analysis (PGNAA) systems employ neutrons as a probe to interrogate items, e.g. chemical warfare materiel-filled munitions. The choice of a neutron source in field-portable systems is determined by its ability to excite nuclei of interest, operational concerns such as radiological safety and ease-of-use, and cost. Idaho National Laboratory’s PINS Chemical Assay System has traditionally used a Cf-252 isotopic neutron source, but recently a Deuterium-Tritium (DT) Electronic Neutron Generator (ENG) has been tested as an alternate neutron source. This paper presents the results of using both of these neutron sources to interrogate chemical warfare materiel (CWM) and high explosive (HE) filled munitions.
Date: August 1, 2008
Creator: Seabury, E. H.; Chichester, D. L.; Wharton, C. J. & Caffrey, A. J.
Object Type: Article
System: The UNT Digital Library
Cost and Reliability Improvement for CIGS-Based PV on Flexible Substrate: Annual Technical Report, 24 May 2006 - 25 September 2007 (open access)

Cost and Reliability Improvement for CIGS-Based PV on Flexible Substrate: Annual Technical Report, 24 May 2006 - 25 September 2007

Global Solar Energy has enhanced module reliability, reduced cost and improved performance of its CIGS deposition process, and reduced cost of materials and processes for contacts.
Date: August 1, 2008
Creator: Weideman, S.
Object Type: Report
System: The UNT Digital Library