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Active Detection of Small Quantities of Shielded Highly-Enriched Uranium Using Low-Dose 60-keV Neutron Interrogation (open access)

Active Detection of Small Quantities of Shielded Highly-Enriched Uranium Using Low-Dose 60-keV Neutron Interrogation

Active interrogation with low-energy neutrons provides a search technique for shielded highly-enriched uranium. We describe the technique and show initial results using a low-dose 60 keV neutron beam. This technique produces a clear induced fission signal in the presence of small quantities of {sup 235}U. The technique has been validated with low-Z and high-Z shielding materials. The technique uses a forward-directed beam of 60 keV neutrons to induce fission in {sup 235}U. The induced fission produces fast neutrons which are then detected as the signature for {sup 235}U. The beam of neutrons is generated with a 1.93 MeV proton beam impinging on a natural lithium target. The proton beam is produced by a radio-frequency quadrupole (RFQ) LINAC. The 60 keV neutron beam is forward directed because the {sup 7}Li(p,n) reaction is just at threshold for the proton energy of 1.93 MeV.
Date: August 16, 2006
Creator: Kerr, P.; Rowland, M.; Dietrich, D.; Stoeffl, W.; Wheeler, B.; Nakae, L. et al.
Object Type: Article
System: The UNT Digital Library
Analysis and Interpretation of Hard X-ray Emission from the Bullet Cluster (1E0657-56), the Most Distant Cluster of Galaxies Observed by RXTE (open access)

Analysis and Interpretation of Hard X-ray Emission from the Bullet Cluster (1E0657-56), the Most Distant Cluster of Galaxies Observed by RXTE

Evidence for non-thermal activity in clusters of galaxies is well established from radio observations of synchrotron emission by relativistic electrons. New windows in the Extreme Ultraviolet and Hard X-ray ranges have provided for more powerful tools for the investigation of this phenomenon. Detection of hard X-rays in the 20 to 100 keV range have been reported from several clusters of galaxies, notably from Coma and others. Based on these earlier observations we identified the relatively high redshift cluster 1E0657-56 (also known as RX J0658-5557) as a good candidate for hard X-ray observations. This cluster, also known as the bullet cluster, has many other interesting and unusual features, most notably that it is undergoing a merger, clearly visible in the X-ray images. Here we present results from a successful RXTE observations of this cluster. We summarize past observations and their theoretical interpretation which guided us in the selection process. We describe the new observations and present the constraints we can set on the flux and spectrum of the hard X-rays. Finally we discuss the constraints one can set on the characteristics of accelerated electrons which produce the hard X-rays and the radio radiation.
Date: August 16, 2006
Creator: Petrosian, Vahe; Madejski, Greg & Luli, Kevin
Object Type: Article
System: The UNT Digital Library
Analysis and Modeling of DIII-D Hybrid Discharges and their Extrapolation to ITER (open access)

Analysis and Modeling of DIII-D Hybrid Discharges and their Extrapolation to ITER

Recent experiments on tokamaks around the world [1-5] have demonstrated discharges with moderately high performance in which the q-profile remains stationary, as measured by the motional Stark effect diagnostic, for periods up to several {tau}{sub R}. Hybrid discharges are characterize by q{sub min} {approx} 1, high {beta}{sub N}, and good confinement. These discharges have been termed hybrid because of their intermediate nature between that of an ordinary H-mode and advanced tokamak discharges. They form an attractive scenario for ITER as the normalized fusion performance ({beta}{sub N}H{sub 89P}/q{sub 95}{sup 2}) is at or above that for the ITER baseline Q{sub fus} = 10 scenario, even for q{sub 95} as high as 4.6. The startup phase is thought to be crucial to the ultimate evolution of the hybrid discharge. An open question is how hybrid discharges achieve and maintain their stationary state during the initial startup phase. To investigate this aspect of hybrid discharges, we have used the CORSICA code to model the early stages of a discharge. Results clearly indicate that neoclassical current evolution alone is insufficient to account for the time evolution of the q-profile and that an addition of non-inductive current source must be incorporated into the model to …
Date: June 16, 2006
Creator: Makowski, M. A.; Casper, T. A.; Jayakumar, R. J.; Pearlstein, L. D.; Petty, C. C. & Wade, M. R.
Object Type: Article
System: The UNT Digital Library
An Analysis of the DER Adoption Climate in Japan UsingOptimization Results for Prototype Buildings with U.S. Comparisons (open access)

An Analysis of the DER Adoption Climate in Japan UsingOptimization Results for Prototype Buildings with U.S. Comparisons

This research demonstrates economically optimal distributedenergy resource (DER) system choice using the DER choice and operationsoptimization program, the Distributed Energy Resources Customer AdoptionModel (DER-CAM). DER-CAM finds the optimal combination of installedequipment given prevailing utility tariffs and fuel prices, siteelectrical and thermal loads (including absorption cooling), and a menuof available equipment. It provides a global optimization, albeitidealized, that shows how site useful energy loads can be served atminimum cost. Five prototype Japanese commercial buildings are examinedand DER-CAM is applied to select the economically optimal DER system foreach. Based on the optimization results, energy and emission reductionsare evaluated. Significant decreases in fuel consumption, carbonemissions, and energy costs were seen in the DER-CAM results. Savingswere most noticeable in the prototype sports facility, followed by thehospital, hotel, and office building. Results show that DER with combinedheat and power equipment is a promising efficiency and carbon mitigationstrategy, but that precise system design is necessary. Furthermore, aJapan-U.S. comparison study of policy, technology, and utility tariffsrelevant to DER installation is presented.
Date: June 16, 2006
Creator: Zhou, Nan; Marnay, Chris; Firestone, Ryan; Gao, Weijun & Nishida,Masaru
Object Type: Article
System: The UNT Digital Library
Analytical Approach to Eigen-Emittance Evolution in Storage Rings (open access)

Analytical Approach to Eigen-Emittance Evolution in Storage Rings

This dissertation develops the subject of beam evolution in storage rings with nearly uncoupled symplectic linear dynamics. Linear coupling and dissipative/diffusive processes are treated perturbatively. The beam distribution is assumed Gaussian and a function of the invariants. The development requires two pieces: the global invariants and the local stochastic processes which change the emittances, or averages of the invariants. A map based perturbation theory is described, providing explicit expressions for the invariants near each linear resonance, where small perturbations can have a large effect. Emittance evolution is determined by the damping and diffusion coefficients. The discussion is divided into the cases of uniform and non-uniform stochasticity, synchrotron radiation an example of the former and intrabeam scattering the latter. For the uniform case, the beam dynamics is captured by a global diffusion coefficient and damping decrement for each eigen-invariant. Explicit expressions for these quantities near coupling resonances are given. In many cases, they are simply related to the uncoupled values. Near a sum resonance, it is found that one of the damping decrements becomes negative, indicating an anti-damping instability. The formalism is applied to a number of examples, including synchrobetatron coupling caused by a crab cavity, a case of current interest …
Date: May 16, 2006
Creator: Nash, Boaz
Object Type: Report
System: The UNT Digital Library
An application of Fleck effective scattering to the difference formulation for photon transport (open access)

An application of Fleck effective scattering to the difference formulation for photon transport

We introduce a new treatment of the difference formulation[1] for photon radiation transport without scattering in 1d slab geometry that is closely analogous to that of Fleck and Cummings[2] for the traditional formulation. The resulting form is free of implicit source terms and has the familiar effective scattering of the field of transport.
Date: October 16, 2006
Creator: Daffin, F.
Object Type: Report
System: The UNT Digital Library
Arctic National Wildlife Refuge (ANWR): Controversies for the 109th Congress (open access)

Arctic National Wildlife Refuge (ANWR): Controversies for the 109th Congress

This report provides information about Arctic National Wildlife Refuge (ANWR) and controversies for the 109th congress.
Date: May 16, 2006
Creator: Corn, M. Lynne; Gelb, Bernald A. & Baldwin, Pamela
Object Type: Report
System: The UNT Digital Library
Armenia, Azerbaijan, and Georgia: Political Developments and Implications for U.S. Interests (open access)

Armenia, Azerbaijan, and Georgia: Political Developments and Implications for U.S. Interests

None
Date: November 16, 2006
Creator: Nichol, Jim
Object Type: Report
System: The UNT Digital Library
Arts and Humanities: Background on Funding (open access)

Arts and Humanities: Background on Funding

This report
Date: February 16, 2006
Creator: Boren, Susan
Object Type: Report
System: The UNT Digital Library
The Back End of the Fuel Cycle Moves Front and Center (open access)

The Back End of the Fuel Cycle Moves Front and Center

For many years, the commercial nuclear business has remained relatively stable in many ways. The introduction of new plants, the spread to new countries, and the development of key elements of the fuel cycle such as enrichment, reprocessing and waste disposal have been quite modest. That is unlikely to be the case in the coming years. A number of events and trends are becoming increasingly apparent and are cause for both opportunity and caution: (1) New nuclear power plant orders are likely to grow and spread, particularly in the developing world, e.g. China and India. (2) The growing recognition that the developing world will be a major competitor for limited energy resources is raising awareness in the developed world regarding concerns for future energy security. (3) Clearer evidence of the effects of greenhouse gas emissions on global warming, largely from the burning of fossil fuels, is creating more attention on the environmental benefits of nuclear power. (4) The last decade has shown unequivocal evidence of countries lying, cheating on their NPT obligation, and covertly carrying out nuclear weapons-related activities. Some have suggested their presumed need for a domestic nuclear fuel cycle as a rationale to pursue enrichment and/or reprocessing capabilities, …
Date: February 16, 2006
Creator: Isaacs, T & Choi, J
Object Type: Article
System: The UNT Digital Library
Balkan Cooperation on War Crimes Issues (open access)

Balkan Cooperation on War Crimes Issues

In early May 2006, assessments of insufficient Serbian cooperation with the International Criminal Tribunal for the former Yugoslavia (ICTY) led the European Union (EU) to suspend association talks with Serbia. Later that month, the U.S. Secretary of State withheld certification of full Serbian cooperation with ICTY, leading to a partial suspension of U.S. bilateral assistance to Serbia. From late 2004 through early 2005, a combination of intensified international pressure and deadlines associated with Euro-Atlantic integration processes prompted a spate of transfers of indicted persons to the tribunal. Full cooperation with ICTY is a key prerequisite to further progress toward a shared long-term goal for the western Balkan countries: closer association with and eventual membership in the European Union and NATO.
Date: June 16, 2006
Creator: Kim, Julie
Object Type: Report
System: The UNT Digital Library
Balkan Cooperation on War Crimes Issues (open access)

Balkan Cooperation on War Crimes Issues

The report is about the Balkan Cooperation on War Crimes Issues.In early May 2006, assessments of insufficient Serbian cooperation with the International Criminal Tribunal for the former Yugoslavia (ICTY) led the European Union (EU) to suspend association talks with Serbia. Later that month, the U.S. Secretary of State withheld certification of full Serbian cooperation with ICTY, leading to a partial suspension of U.S. bilateral assistance to Serbia.
Date: June 16, 2006
Creator: Kim, Julie
Object Type: Report
System: The UNT Digital Library
The Basel Accords: The Implementation of II and the Modification of I (open access)

The Basel Accords: The Implementation of II and the Modification of I

This report is on The Basel Accords: The Implementation of II and the Modification of I.
Date: June 16, 2006
Creator: Eubanks, Walter W.
Object Type: Report
System: The UNT Digital Library
Beam Instrumentation Challenges at the International Linear Collider (open access)

Beam Instrumentation Challenges at the International Linear Collider

The International Linear Collider (ILC) is a proposed facility for the study of high energy physics through electron-positron collisions at center-of-mass energies up to 500 GeV and luminosities up to 2 x 10{sup 34} cm{sup -2} sec{sup -1}. Meeting the ILC's goals will require an extremely sophisticated suite of beam instruments for the preservation of beam emittance, the diagnosis of optical errors and mismatches, the determination of beam properties required for particle physics purposes, and machine protection. The instrumentation foreseen for the ILC is qualitatively similar to equipment in use at other accelerator facilities in the world, but in many cases the precision, accuracy, stability, or dynamic range required by the ILC exceed what is typically available in today's accelerators. In this paper we survey the beam instrumentation requirements of the ILC and describe the system components which are expected to meet those requirements.
Date: May 16, 2006
Creator: Tenenbaum, Peter
Object Type: Article
System: The UNT Digital Library
Benchmark of the IMPACT Code for High Intensity Beam DynamicsSimulation (open access)

Benchmark of the IMPACT Code for High Intensity Beam DynamicsSimulation

The IMPACT (Integrated Map and Particle Accelerator Tracking) code was first developed under Computational Grand Challenge project in the mid 1990s [1]. It started as a three-dimensional (3D) data parallel particle-in-cell (PIC) code written in High Performance Fortran. The code used a split-operator based method to solve the Hamiltonian equations of motion. It contained linear transfer maps for drifts, quadrupole magnets and rf cavities. The space-charge forces were calculated using an FFT-based method with 3D open boundary conditions and longitudinal periodic boundary conditions. This code was completely rewritten in the late 1990s based on a message passing parallel programming paradigm using Fortran 90 and MPI following an object-oriented software design. This improved the code's scalability on large parallel computer systems and also gave the code better software maintainability and extensibility [2]. In the following years, under the SciDAC-1 accelerator project, the code was extended to include more accelerating and focusing elements such as DTL, CCL, superconducting linac, solenoid, dipole, multipoles, and others. Besides the original split-operator based integrator, a direct integration of Lorentz equations of motion using a leap-frog algorithm was also added to the IMPACT code to handle arbitrary external nonlinear fields. This integrator can read in 3D electromagnetic …
Date: November 16, 2006
Creator: Qiang, J. & Ryne, R.D.
Object Type: Article
System: The UNT Digital Library
Biogeochemical Cycling and Environmental Stability of Plutonium Relevant to Long-Term Stewardship of Doe Sites. (open access)

Biogeochemical Cycling and Environmental Stability of Plutonium Relevant to Long-Term Stewardship of Doe Sites.

Pu is generally considered to be relatively immobile in the terrestrial environment, with the exception of transport via airborne and erosion mechanisms. More recently the transport of colloidal forms of Pu is being studied as a mobilization pathway from subsurface contaminated soils and sediments. The overall objective of this research is to understand the biogeochemical cycling of Pu in environments of interest to long-term DOE stewardship issues. Microbial processes are central to the immobilization of Pu species, through the metabolism of organically complexed Pu species and Pu associated with extracellular carrier phases and the creation of environments favorable for retardation of Pu transport.
Date: November 16, 2006
Creator: Francis, A. J.; Gillow, J. P. & DODGE, C. J.
Object Type: Report
System: The UNT Digital Library
Border Trade Advisory Committee Report (open access)

Border Trade Advisory Committee Report

This report summarizes the Border Trade Advisory Committee's meeting on July 19th, 2006, during which their goals, strategies, and principles were discussed.
Date: November 16, 2006
Creator: unknown
Object Type: Text
System: The Portal to Texas History
Brazil’s Agricultural Production and Exports: Selected Data (open access)

Brazil’s Agricultural Production and Exports: Selected Data

This report provides Selected Data related to Brazil’s Agricultural Production and Exports insluding soybeans,poultry,beef,pork,orange juice and coffee.
Date: October 16, 2006
Creator: Council, Rishard Logan & Hanrahan, Charles E.
Object Type: Report
System: The UNT Digital Library
Brief Summaries of Federal Animal Protection Status (open access)

Brief Summaries of Federal Animal Protection Status

This report contains brief summaries of federal animal protection statutes, listed alphabetically. It does not include treaties, although it does include statutes enacted to implement treaties. It includes statutes concerning animals that are not entirely, or not at all, animal protection statutes. For example, it includes a statute authorizing the eradication of predators, because one of the statute’s purposes is to protect domestic and “game” animals; and it includes statutes to conserve fish, although their ultimate purpose may not be for the fishes’ benefit. It also includes statutes that allow the disabled to use service animals, and even includes statutes aimed at acts of animal rights advocates (the Animal Enterprise Protection Act of 1992, and the Recreational Hunting Safety and Preservation Act of 1994).
Date: October 16, 2006
Creator: Cohen, Henry
Object Type: Report
System: The UNT Digital Library
Brief Summaries of Federal Animal Protection Statutes (open access)

Brief Summaries of Federal Animal Protection Statutes

This report contains brief summaries of federal animal protection statutes, listed alphabetically. It includes statutes enacted to implement treaties, those that protect certain groups of animals (e.g., protection of "game" animals rather than predators), statutes to conserve fish, statutes that allow the disabled to use service animals, and statutes aimed at acts of animal rights advocates (the Animal Enterprise Protection Act of 1992, and the Recreational Hunting Safety and Preservation Act of 1994).
Date: October 16, 2006
Creator: Cohen, Henry
Object Type: Report
System: The UNT Digital Library
The Budget for Fiscal Year 2007 (open access)

The Budget for Fiscal Year 2007

This report consists of the budget for fiscal year 2007.
Date: November 16, 2006
Creator: Winters, Philip D.
Object Type: Report
System: The UNT Digital Library
Bureau of the Public Debt: Areas for Improvement in Information Security Controls (open access)

Bureau of the Public Debt: Areas for Improvement in Information Security Controls

Correspondence issued by the Government Accountability Office with an abstract that begins "In connection with fulfilling our requirement to audit the financial statements of the U.S. government, we audited and reported on the Schedules of Federal Debt Managed by the Bureau of the Public Debt (BPD) for the fiscal years ended September 30, 2005 and 2004. As part of these audits, we performed a review of the general and application information security controls over key BPD financial systems. This report presents the issues identified during our fiscal year 2005 testing of the general and application information security controls that support key BPD automated financial systems relevant to BPD's Schedule of Federal Debt. This report also includes the results of our follow-up on the status of BPD's corrective actions to address recommendations that were contained in our prior years' audits and open as of September 30, 2004. We also assessed the general and application information security controls over key BPD financial systems that the Federal Reserve Banks (FRB) maintain and operate on behalf of BPD. We will issue a separate report to the Board of Governors of the Federal Reserve System on the results of such testing."
Date: March 16, 2006
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library
Capitol Power Plant Utility Tunnels (open access)

Capitol Power Plant Utility Tunnels

Correspondence issued by the Government Accountability Office with an abstract that begins "The Architect of the Capitol (AOC), through the Capitol Power Plant (CPP), operates five walkable utility tunnels containing steam and chilled water pipes associated with serving the heating and cooling requirements of the U.S. Capitol and 23 surrounding facilities. The tunnels also carry other utilities, such as fiber optic and telephone lines. The Office of Compliance (OOC), which is responsible for advancing safety, health, and workplace rights in the legislative branch, and the tunnel workers have raised concerns about health and safety issues in the tunnels. Specifically, in March 2006, the utility tunnel workers sent a letter to Congress complaining of unsafe working conditions in the tunnels, including falling concrete, asbestos, and extreme heat. In February 2006, OOC filed a complaint against AOC concerning hazards in the tunnels, including falling concrete, an inadequate communication system for these confined spaces, and inadequate escape exits. According to OOC officials, these conditions had been previously brought to the attention of AOC by OOC inspectors as early as 1999. Following a reinspection in mid-2005, OOC determined that AOC had not made sufficient progress in addressing them and that conditions in the tunnels …
Date: November 16, 2006
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library
Central Asia: Regional Developments and Implications for U.S. Interests (open access)

Central Asia: Regional Developments and Implications for U.S. Interests

This report mainly focuses on Regional Developments and Implications for U.S. Interests in Central Asia after the collapse of soviet union in 1991.
Date: November 16, 2006
Creator: Nichol, Jim
Object Type: Report
System: The UNT Digital Library