Constructing Integrable High-pressure Full-current Free-boundary Stellarator Magnetohydrodynamic Equilibrium Solutions (open access)

Constructing Integrable High-pressure Full-current Free-boundary Stellarator Magnetohydrodynamic Equilibrium Solutions

For the (non-axisymmetric) stellarator class of plasma confinement devices to be feasible candidates for fusion power stations it is essential that, to a good approximation, the magnetic field lines lie on nested flux surfaces; however, the inherent lack of a continuous symmetry implies that magnetic islands responsible for breaking the smooth topology of the flux surfaces are guaranteed to exist. Thus, the suppression of magnetic islands is a critical issue for stellarator design, particularly for small aspect ratio devices. Pfirsch-Schluter currents, diamagnetic currents, and resonant coil fields contribute to the formation of magnetic islands, and the challenge is to design the plasma and coils such that these effects cancel. Magnetic islands in free-boundary high-pressure full-current stellarator magnetohydrodynamic equilibria are suppressed using a procedure based on the Princeton Iterative Equilibrium Solver [Reiman and Greenside, Comp. Phys. Comm. 43 (1986) 157] which iterate s the equilibrium equations to obtain the plasma equilibrium. At each iteration, changes to a Fourier representation of the coil geometry are made to cancel resonant fields produced by the plasma. The changes are constrained to preserve certain measures of engineering acceptability and to preserve the stability of ideal kink modes. As the iterations continue, the coil geometry and …
Date: September 15, 2003
Creator: Hudson, S. R.; Monticello, D. A.; Reiman, A. H.; Strickler, D. J.; Hirshman, S. P.; Ku, L. P. et al.
Object Type: Report
System: The UNT Digital Library
Defense Acquisitions: Improvements Needed in Space Systems Acquisition Management Policy (open access)

Defense Acquisitions: Improvements Needed in Space Systems Acquisition Management Policy

A letter report issued by the General Accounting Office with an abstract that begins "The Department of Defense is spending nearly $18 billion annually to develop, acquire, and operate satellites and other space-related systems. The majority of satellite programs that GAO has reviewed over the past 2 decades experienced increased costs and delayed schedules. DOD has recently implemented a new acquisition management policy, which sets the stage for decision making on individual space programs. GAO was asked to assess the new policy."
Date: September 15, 2003
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library
Depot Maintenance: DOD's 50-50 Reporting Should Be Streamlined (open access)

Depot Maintenance: DOD's 50-50 Reporting Should Be Streamlined

A letter report issued by the General Accounting Office with an abstract that begins "Under 10 U.S.C. 2466, not more than 50 percent of each military department's annual depot maintenance funding can be used for work done by private-sector contractors. The Department of Defense (DOD) also must submit two reports to the Congress annually on the division of depot maintenance funding between the public and private sectors--one about the percentage of funds spent in the previous 2 fiscal years (prior-years report) and one about the current and 4 succeeding fiscal years (future-years report). As required, GAO reviewed the two DOD reports submitted in early 2003 and is, with this report, submitting its views to the Congress on whether (1) the military services met the so-called "50-50 requirement" for fiscal years 2001-2 and (2) the projections for fiscal years 2003-7 are reasonable estimates. GAO also identified opportunities to improve the reporting process."
Date: September 15, 2003
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library
Design issues for cryogenic cooling of short periodsuperconducting undulators (open access)

Design issues for cryogenic cooling of short periodsuperconducting undulators

Superconducting insertion devices, which produce periodic magnetic fields, have been built and installed in a number of synchrotron-light source storage-rings. For the most part, these devices have been wigglers, which have relatively long period lengths. This report concerns itself with the special cryogenic issues associated with short period undulators. The motivation for considering the incorporation of superconducting technology in insertion device designs is to achieve higher magnetic fields than can be achieved with more conventional permanent magnet technology. Since the peak field decreases sharply with increased magnet gap to period ratio, the cryogenic design of the magnet system is crucial. In particular, the insulation required for a warm vacuum bore device is impractical for short period undulators. This report describes the issues that are related to a cold bore ({approx}4 K) and an intermediate temperature bore (30 to 70 K) designs. The criteria for the use of small cryocoolers for cooling a short period undulator are presented. The problems associated with connecting small coolers to an undulator at 4.2 K are discussed.
Date: September 15, 2003
Creator: Green, M. A.; Dietderich, D. R.; Marks, S.; Prestemon, S. O. & Schlueter, R. D.
Object Type: Article
System: The UNT Digital Library
Developing Smart Seismic Arrays: A Simulation Environment, Observational Database, and Advanced Signal Processing (open access)

Developing Smart Seismic Arrays: A Simulation Environment, Observational Database, and Advanced Signal Processing

Seismic imaging and tracking methods have intelligence and monitoring applications. Current systems, however, do not adequately calibrate or model the unknown geological heterogeneity. Current systems are also not designed for rapid data acquisition and analysis in the field. This project seeks to build the core technological capabilities coupled with innovative deployment, processing, and analysis methodologies to allow seismic methods to be effectively utilized in the applications of seismic imaging and vehicle tracking where rapid (minutes to hours) and real-time analysis is required. The goal of this project is to build capabilities in acquisition system design, utilization and in full 3D finite difference modeling as well as statistical characterization of geological heterogeneity. Such capabilities coupled with a rapid field analysis methodology based on matched field processing are applied to problems associated with surveillance, battlefield management, finding hard and deeply buried targets, and portal monitoring. This project benefits the U.S. military and intelligence community in support of LLNL's national-security mission. FY03 was the final year of this project. In the 2.5 years this project has been active, numerous and varied developments and milestones have been accomplished. A wireless communication module for seismic data was developed to facilitate rapid seismic data acquisition and …
Date: September 15, 2003
Creator: Harben, P E; Harris, D; Myers, S; Larsen, S; Wagoner, J; Trebes, J et al.
Object Type: Report
System: The UNT Digital Library
DPAL: A New Class of Lasers for CW Power Beaming at Ideal Photovoltaic Cell Wavelengths (open access)

DPAL: A New Class of Lasers for CW Power Beaming at Ideal Photovoltaic Cell Wavelengths

The new class of diode pumped alkali vapor lasers (DPALs) offers high efficiency cw laser beams at wavelengths which efficiently couple to photovoltaic (PV) cells: silicon cells at 895 nm (cesium), and GaAs cells at 795 nm (rubidium) and at 770 nm (potassium). DPAL electrical efficiencies of 25-30% are projected, enabling PV cell efficiencies {approx}40% (Si) and {approx}60% (GaAs). Near-diffraction-limited DPAL device power scaling into the multi-kilowatt regime from a single aperture is projected.
Date: September 15, 2003
Creator: Krupke, W F; Beach, R J; Payne, S A; Kanz, V K & Early, J T
Object Type: Article
System: The UNT Digital Library
EARLY ENTRANCE COPRODUCTION PLANT (open access)

EARLY ENTRANCE COPRODUCTION PLANT

The 1999 U. S. Department of Energy (DOE) award to Texaco Energy Systems Inc. (presently Texaco Energy Systems LLC, a subsidiary of ChevronTexaco) was made to provide a Preliminary Engineering Design of an Early Entrance Coproduction Plant (EECP). Since the award presentation, work has been undertaken to achieve an economical concept design that makes strides toward the DOE Vision 21 goal. The objective of the EECP is to convert coal and/or petroleum coke to electric power plus transportation fuels, chemicals and useful utilities such as steam. The use of petroleum coke was added as a fuel to reduce the cost of feedstock and also to increase the probability of commercial implementation of the EECP concept. This objective has been pursued in a three phase effort through the partnership of the DOE with prime contractor Texaco Energy Systems LLC and subcontractors General Electric (GE), Praxair, and Kellogg Brown and Root (KBR). ChevronTexaco is providing gasification technology and Rentech's Fischer-Tropsch technology that has been developed for non-natural gas feed sources. GE is providing gas turbine technology for the combustion of low energy content gas. Praxair is providing air separation technology, and KBR is providing engineering to integrate the facility. The objective of …
Date: September 15, 2003
Creator: Benham, Charles; Bohn, Mark; Anderson, John; Berry, Earl; Brent, Fred; He, Ming et al.
Object Type: Report
System: The UNT Digital Library
Energy Policy: The Continuing Debate (open access)

Energy Policy: The Continuing Debate

On April 10, 2003, the House passed comprehensive energy legislation, H.R. 6 (247- 175). The bill was a composite of four measures – H.R. 39, reported from the House Committee on Resources, H.R. 238, marked up by the House Science Committee, H.R. 1531, reported from Ways and Means, and an unnumbered bill reported out of the Energy and Commerce Committee. Unlike comprehensive energy legislation (H.R. 4) debated in the 107th Congress, H.R. 6 includes a section on electricity which has stirred some controversy. H.R. 6 would provide authorization for exploration and development of the Arctic National Wildlife Refuge (ANWR).
Date: September 15, 2003
Creator: Bamberger, Robert L.
Object Type: Report
System: The UNT Digital Library
Fair Credit Reporting Act: Frequently Asked Questions (open access)

Fair Credit Reporting Act: Frequently Asked Questions

As financial privacy issues are debated in Congress, numerous questions about the Fair Credit Reporting Act (FCRA) have emerged. Enacted in 1970, the Fair Credit Reporting Act is the federal statute that establishes a regulatory framework for credit reporting in the United States and establishes a consumer’s rights with respect to his or her credit report. This report attempts to answer frequently asked questions about the Fair Credit Reporting Act.
Date: September 15, 2003
Creator: Welborn, Angie A. & Nott, Loretta
Object Type: Report
System: The UNT Digital Library
Fiber-Optic Laser Raman Spectroscopy Sensor (open access)

Fiber-Optic Laser Raman Spectroscopy Sensor

The Defense Programs Plant Directed Research and Development Program sponsored the optimization and interface of a fiber-optic Raman sensor as a complementary technique to mass spectrometry currently used in the Tritium Facility for measuring hydrogen isotopes. This sensor will provide real-time feedback while reducing the sample load for off-line gas analysis by the Tritium mass spectrometers. The compact Raman system incorporates a 488 nanometer laser system, spectrometer and detector along with a 20-foot fiber-optic probe. The analysis of gas mixtures of protium and deuterium at various compositions and total pressures ranging form 11 to 5000 torr showed good signal to noise ratios using very short integration times (15 seconds). The detection limits for protium and deuterium ranged from 0.5 percent to 0.8 percent. This probe will be demonstrated in-line in the new HT TCAP (hydrogen-tritium thermal cycling absorption process) cold runs.
Date: September 15, 2003
Creator: Ziegler, K. E.
Object Type: Report
System: The UNT Digital Library
Focusing solenoids for the MICE cooling channel (open access)

Focusing solenoids for the MICE cooling channel

This report describes a design for focusing solenoids for the low beta sections for the proposed Muon Ionization Cooling Experiment (MICE). There are three focusing solenoid pairs that will be around the muon absorbers for MICE. The two solenoid coils have an inside diameter of 510 mm, a length of 180 mm, and a thickness of 100 mm. A distance of 260 mm separates the two coils in the pair. The coils are designed to operate at opposite polarity, in order to create a gradient field in the low beta sections of the MICE cooling channel. As result, the force pushing the coil pair apart approaches 270 metric tons when the coils operate close to the short sample current for the superconductor. The forces between the coils will be carried by a support structure that is both on the inside and the outside the coils. During some modes of operation for MICE, the coils may operate at the same polarity, which means that the force between the coils pushes them together. The focusing magnet must be designed for both modes of operation. This support structure for the coils will be part of the focusing magnet quench protection system.
Date: September 15, 2003
Creator: Green, M.A.; Baynham, E.; Barr, G.; Lau, W.; Rochford, J.H. & Yang, S.
Object Type: Article
System: The UNT Digital Library
Grid-based Parallel Data Streaming Implemented for the Gyrokinetic Toroidal Code (open access)

Grid-based Parallel Data Streaming Implemented for the Gyrokinetic Toroidal Code

We have developed a threaded parallel data streaming approach using Globus to transfer multi-terabyte simulation data from a remote supercomputer to the scientist's home analysis/visualization cluster, as the simulation executes, with negligible overhead. Data transfer experiments show that this concurrent data transfer approach is more favorable compared with writing to local disk and then transferring this data to be post-processed. The present approach is conducive to using the grid to pipeline the simulation with post-processing and visualization. We have applied this method to the Gyrokinetic Toroidal Code (GTC), a 3-dimensional particle-in-cell code used to study microturbulence in magnetic confinement fusion from first principles plasma theory.
Date: September 15, 2003
Creator: Klasky, S.; Ethier, S.; Lin, Z.; Martins, K.; McCune, D. & Samtaney, R.
Object Type: Report
System: The UNT Digital Library
Haplotypes in the APOA1-C3-A4-A5 gene cluster affect plasma lipids in both humans and baboons (open access)

Haplotypes in the APOA1-C3-A4-A5 gene cluster affect plasma lipids in both humans and baboons

Genetic studies in non-human primates serve as a potential strategy for identifying genomic intervals where polymorphisms impact upon human disease-related phenotypes. It remains unclear, however, whether independently arising polymorphisms in orthologous regions of non-human primates leads to similar variation in a quantitative trait found in both species. To explore this paradigm, we studied a baboon apolipoprotein gene cluster (APOA1/C3/A4/A5) for which the human gene orthologs have well established roles in influencing plasma HDL-cholesterol and triglyceride concentrations. Our extensive polymorphism analysis of this 68 kb gene cluster in 96 pedigreed baboons identified several haplotype blocks each with limited diversity, consistent with haplotype findings in humans. To determine whether baboons, like humans, also have particular haplotypes associated with lipid phenotypes, we genotyped 634 well characterized baboons using 16 haplotype tagging SNPs. Genetic analysis of single SNPs, as well as haplotypes, revealed an association of APOA5 and APOC3 variants with HDL cholesterol and triglyceride concentrations, respectively. Thus, independent variation in orthologous genomic intervals does associate with similar quantitative lipid traits in both species, supporting the possibility of uncovering human QTL genes in a highly controlled non-human primate model.
Date: September 15, 2003
Creator: Wang, Qian-fei; Liu, Xin; O'Connell, Jeff; Peng, Ze; Krauss, Ronald M.; Rainwater, David L. et al.
Object Type: Article
System: The UNT Digital Library
Hatch-Waxman Related Provisions of the Medicare Prescription Drug Bills (H.R. 1 and S. 1): A Side-by-Side Comparison (open access)

Hatch-Waxman Related Provisions of the Medicare Prescription Drug Bills (H.R. 1 and S. 1): A Side-by-Side Comparison

None
Date: September 15, 2003
Creator: Schacht, Wendy H. & Thomas, John R.
Object Type: Report
System: The UNT Digital Library
A heat exchanger between forced flow helium gas at 14 to 18 K andliquid hydrogen at 20 K circulated by natural convection (open access)

A heat exchanger between forced flow helium gas at 14 to 18 K andliquid hydrogen at 20 K circulated by natural convection

The Muon Ionization Cooling Experiment (MICE) has three 350-mm long liquid hydrogen absorbers to reduce the momentum of 200 MeV muons in all directions. The muons are then re-accelerated in the longitudinal direction by 200 MHz RF cavities. The result is cooled muons with a reduced emittance. The energy from the muons is taken up by the liquid hydrogen in the absorber. The hydrogen in the MICE absorbers is cooled by natural convection to the walls of the absorber that are in turn cooled by helium gas that enters at 14 K. This report describes the MICE liquid hydrogen absorber and the heat exchanger between the liquid hydrogen and the helium gas that flows through passages in the absorber wall.
Date: September 15, 2003
Creator: Green, M. A.; Ishimoto, S.; Lau, W. & Yang, S.
Object Type: Article
System: The UNT Digital Library
Human Capital: Insights for U.S. Agencies from Other Countries' Succession Planning and Management Initiatives (open access)

Human Capital: Insights for U.S. Agencies from Other Countries' Succession Planning and Management Initiatives

A letter report issued by the General Accounting Office with an abstract that begins "Leading public organizations here and abroad recognize that a more strategic approach to human capital management is essential for change initiatives that are intended to transform their cultures. To that end, organizations are looking for ways to identify and develop the leaders, managers, and workforce necessary to face the array of challenges that will confront government in the 21st century. GAO conducted this study to identify how agencies in four countries--Australia, Canada, New Zealand, and the United Kingdom--are adopting a more strategic approach to managing the succession of senior executives and other public sector employees with critical skills. These agencies' experiences may provide insights to executive branch agencies as they undertake their own succession planning and management initiatives. GAO identified the examples described in this report through discussions with officials from central human capital agencies, national audit offices, and agencies in Australia, Canada, New Zealand, and the United Kingdom, and a screening survey sent to senior human capital officials at selected agencies."
Date: September 15, 2003
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library
The Innovations, Technology and Waste Management Approaches to Safely Package and Transport the World's First Radioactive Fusion Research Reactor for Burial (open access)

The Innovations, Technology and Waste Management Approaches to Safely Package and Transport the World's First Radioactive Fusion Research Reactor for Burial

Original estimates stated that the amount of radioactive waste that will be generated during the dismantling of the Tokamak Fusion Test Reactor will approach two million kilograms with an associated volume of 2,500 cubic meters. The materials were activated by 14 MeV neutrons and were highly contaminated with tritium, which present unique challenges to maintain integrity during packaging and transportation. In addition, the majority of this material is stainless steel and copper structural metal that were specifically designed and manufactured for this one-of-a-kind fusion research reactor. This provided further complexity in planning and managing the waste. We will discuss the engineering concepts, innovative practices, and technologies that were utilized to size reduce, stabilize, and package the many unique and complex components of this reactor. This waste was packaged and shipped in many different configurations and methods according to the transportation regulations and disposal facility requirements. For this particular project, we were able to utilize two separate disposal facilities for burial. This paper will conclude with a complete summary of the actual results of the waste management costs, volumes, and best practices that were developed from this groundbreaking and successful project.
Date: September 15, 2003
Creator: Rule, Keith; Perry, Erik; Chrzanowski, Jim; Viola, Mike & Strykowsky, Ron
Object Type: Report
System: The UNT Digital Library
Interannual Variability in Global Soil Respiration on a 0.5 Degree Grid Cell Basis (1980-1994) (open access)

Interannual Variability in Global Soil Respiration on a 0.5 Degree Grid Cell Basis (1980-1994)

We used a climate-driven regression model to develop spatially resolved estimates of soil-CO{sub 2} emissions from the terrestrial land surface for each month from January 1980 to December 1994, to evaluate the effects of interannual variations in climate on global soil-to-atmosphere CO{sub 2} fluxes. The mean annual global soil-CO{sub 2} flux over this 15-y period was estimated to be 80.4 (range 79.3-81.8) Pg C. Monthly variations in global soil-CO{sub 2} emissions followed closely the mean temperature cycle of the Northern Hemisphere. Globally, soil-CO{sub 2} emissions reached their minima in February and peaked in July and August. Tropical and subtropical evergreen broad-leaved forests contributed more soil-derived CO{sub 2} to the atmosphere than did any other vegetation type ({approx}30% of the total) and exhibited a biannual cycle in their emissions. Soil-CO{sub 2} emissions in other biomes exhibited a single annual cycle that paralleled the seasonal temperature cycle. Interannual variability in estimated global soil-CO{sub 2} production is substantially less than is variability in net carbon uptake by plants (i.e., net primary productivity). Thus, soils appear to buffer atmospheric CO{sub 2} concentrations against far more dramatic seasonal and interannual differences in plant growth. Within seasonally dry biomes (savannas, bushlands, and deserts), interannual variability in …
Date: September 15, 2003
Creator: Raich, J.W.
Object Type: Report
System: The UNT Digital Library
LHC detector upgrades (open access)

LHC detector upgrades

The LHC detectors are well into their construction phase. The LHC schedule shows first beam to ATLAS and CMS in 2007. Because the LHC accelerator has begun to plan for a ten fold increase in LHC design luminosity (the SLHC or super LHC) it is none too soon to begin to think about the upgrades which will be required of the present LHC detectors. In particular, the tracking systems of ATLAS and CMS will need to be completely rebuilt. Given the time needed to do the R & D, make prototypes, and construct the new detectors and given the accelerator schedule for the SLHC, work needs to begin rather soon.
Date: September 15, 2003
Creator: Green, Dan
Object Type: Article
System: The UNT Digital Library
Lumber Imports from Canada: Issues and Events (open access)

Lumber Imports from Canada: Issues and Events

This report discuses lumber imports from Canada and provides a concise historical account of the dispute, summarizes the subsidy and injury evidence, and discusses the current issues and events.
Date: September 15, 2003
Creator: Gorte, Ross W. & Grimmett, Jeanne J.
Object Type: Report
System: The UNT Digital Library
Marginal Stability Boundaries for Infinite-n Ballooning Modes in a Quasi-axisymmetric Stellarator (open access)

Marginal Stability Boundaries for Infinite-n Ballooning Modes in a Quasi-axisymmetric Stellarator

A method for computing the ideal-MHD stability boundaries in three-dimensional equilibria is employed. Following Hegna and Nakajima [Phys. Plasmas 5 (May 1998) 1336], a two-dimensional family of equilibria are constructed by perturbing the pressure and rotational-transform profiles in the vicinity of a flux surface for a given stellarator equilibrium. The perturbations are constrained to preserve the magnetohydrodynamic equilibrium condition. For each perturbed equilibrium, the infinite-n ballooning stability is calculated. Marginal stability diagrams are thus constructed that are analogous to (s; a) diagrams for axisymmetric configurations. A quasi-axisymmetric stellarator is considered. Calculations of stability boundaries generally show regions of instability can occur for either sign of the average magnetic shear. Additionally, regions of second-stability are present.
Date: September 15, 2003
Creator: Hudson, S. R. & Hegna, C. C.
Object Type: Report
System: The UNT Digital Library
Motions to Proceed to Consider in the Senate: Who Offers Them? (open access)

Motions to Proceed to Consider in the Senate: Who Offers Them?

None
Date: September 15, 2003
Creator: unknown
Object Type: Report
System: The UNT Digital Library
The National Ignition Facility High-Energy Ultraviolet Laser System (open access)

The National Ignition Facility High-Energy Ultraviolet Laser System

The National Ignition Facility (NIF), currently under construction at the Lawrence Livermore National Laboratory, is a stadium-sized facility containing a 192-beam, 1 .&Megajoule, 500-Terawatt, ultraviolet laser system together with a 10-meter diameter target chamber with room for nearly 100 experimental diagnostics. When completed, NIF will be the world's largest and most energetic laser experimental system, providing an international center to study inertial confinement fusion and the physics of matter at extreme energy densities and pressures. NIF's 192 energetic laser beams will compress fusion targets to conditions required for thermonuclear burn, liberating more energy than required to initiate the fusion reactions. Other NIF experiments will allow the study of physical processes at temperatures approaching 10{sup 8} K and 10{sup 11} Bar, conditions that exist naturally only in the interior of stars, planets and in nuclear weapons. NIF is now entering the first phases of its laser commissioning program. The first four beams of the NIF laser system have generated 106 kilojoules of infrared light and over 10 kJ at the third harmonic (351 nm). NIF's target experimental systems are also being installed in preparation for experiments to begin in late 2003. This paper provides a detailed look the NIF laser systems, …
Date: September 15, 2003
Creator: Moses, E I
Object Type: Article
System: The UNT Digital Library
Nigeria in Political Transition (open access)

Nigeria in Political Transition

None
Date: September 15, 2003
Creator: Dagne, Theodore S.
Object Type: Report
System: The UNT Digital Library