2-MV electrostatic quadrupole injector for heavy-ion fusion (open access)

2-MV electrostatic quadrupole injector for heavy-ion fusion

High current and low emittance are principal requirements for heavy-ion injection into a linac driver for inertial fusion energy. An electrostatic quadrupole (ESQ) injector is capable of providing these high charge density and low emittance beams. We have modified the existing 2-MV Injector to reduce beam emittance and to double the pulse length. We characterize the beam delivered by the modified injector to the High Current Transport Experiment (HCX) and the effects of finite rise time of the extraction voltage pulse in the diode on the beam head. We demonstrate techniques for mitigating aberrations and reducing beam emittance growth in the injector.
Date: November 10, 2004
Creator: Bieniosek, F. M.; Celata, C. M.; Henestroza, E.; Kwan, J. W.; Prost, L. & Seidl, P. A.
Object Type: Article
System: The UNT Digital Library
1400, +/- 900V PEAK PULSE SWITCH MODE POWER SUPPLIES FOR SNS INJECTION KICKERS. (open access)

1400, +/- 900V PEAK PULSE SWITCH MODE POWER SUPPLIES FOR SNS INJECTION KICKERS.

This paper describes simulation and experimental results for a 1400A, {+-} 900V peak rated, switch mode power supply for SNS Injection Kicker Magnets. For each magnet (13 m{Omega}, 160{micro}H), the power supply must supply controlled pulses at 60 Hz repetition rate. The pulse current must rise from zero to maximum in less than 1 millisec in a controlled manner, flat top for up to 2 millisec, and should fall in a controlled manner to less than 4A within 500{micro}s. The low current performance during fall time is the biggest challenge in this power supply. The simulation results show that to meet the controlled fall of the current and the current ripple requirements, voltage loop bandwidth of at least 10 kHz and switching frequency of at least 100 kHz are required. To achieve high power high frequency switching with IGBT switches, a series connected topology with three phase shifted (O{sup o}, 60{sup o} & 120{sup o}) converters each with 40 kHz switching frequency (IGBT at 20kHz), has been achieved. In this paper, the circuit topology, relevant system specifications and experimental results that meet the requirements of the power supply are described in detail. A unique six pulse SCR rectifier circuit with …
Date: March 10, 2004
Creator: LAMBIASE,R. ENG,W. SANDBERG,J. DEWAN,S. HOLMES,R. RUST,K. ZENG,J.
Object Type: Article
System: The UNT Digital Library
2003 Electronic Spectroscopy and Dynamics - July 6-11, 2003 (open access)

2003 Electronic Spectroscopy and Dynamics - July 6-11, 2003

The Gordon Research Conference (GRC) on 2003 Electronic Spectroscopy and Dynamics - July 6-11, 2003 was held at Bates College, Lewiston, Maine, July 6-11, 2003. The Conference was well-attended with 103 participants (attendees list attached). The attendees represented the spectrum of endeavor in this field coming from academia, industry, and government laboratories, both U.S. and foreign scientists, senior researchers, young investigators, and students. In designing the formal speakers program, emphasis was placed on current unpublished research and discussion of the future target areas in this field. There was a conscious effort to stimulate lively discussion about the key issues in the field today. Time for formal presentations was limited in the interest of group discussions. In order that more scientists could communicate their most recent results, poster presentation time was scheduled. Attached is a copy of the formal schedule and speaker program and the poster program. In addition to these formal interactions, ''free time'' was scheduled to allow informal discussions. Such discussions are fostering new collaborations and joint efforts in the field.
Date: September 10, 2004
Creator: Bernstein, Elliot
Object Type: Article
System: The UNT Digital Library
2003 Laser Diagnostic in Combustion Conference (open access)

2003 Laser Diagnostic in Combustion Conference

The GRC Laser Diagnostics in Combustion aims at bringing together scientists and engineers working in the front edge of research and development to discuss and find new ways to solve problems connected to combustion diagnostics. Laser-based techniques have proven to be very efficient tools for studying combustion processes thanks to features as non-intrusiveness in combination with high spatial and temporal resolution. Major tasks for the community are to develop and apply techniques for quantitative measurements with high precision e.g of species concentrations, temperatures, velocities and particles characteristics (size and concentration). These issues are of global interest, considering that the major part of the World's energy conversion comes from combustion sources and the influence combustion processes have on the environment and society.
Date: September 10, 2004
Creator: Allen, Mark G.
Object Type: Article
System: The UNT Digital Library
2003 Organometallic Chemistry Gordon Conference to be held July 20-25, 2003 (open access)

2003 Organometallic Chemistry Gordon Conference to be held July 20-25, 2003

None
Date: September 10, 2004
Creator: Bullock, R. Morris
Object Type: Article
System: The UNT Digital Library
21st Century Steam for Asteroid Mitigation (open access)

21st Century Steam for Asteroid Mitigation

The systematic requirements to divert an object on an earth-impacting course are developed relating the minimum velocity perturbation (both magnitude and direction) to the time available before impact. This, coupled with the accuracy to which orbits can be determined, restricts the time available for any mitigation technology to operate. Because nuclear energy densities are nearly a million times higher than those possible with chemical bonds, it is the most mass efficient means for storing delivering energy with today's technology. The question is how to most effectively apply that energy. This paper will examine the simple case of shattering the body, as well as a more controlled approach in which one or more small velocity increments divert a body. The optimal approach depends on the detailed circumstances, but in either case, already developed technology permits a successful diversion with a few years to decades of notice. The success of nuclear options on relatively short timescales permits consideration of other technologies that while not so well developed might be sufficiently improved to divert small (100 meter) bodies.
Date: March 10, 2004
Creator: Dearborn, D S
Object Type: Article
System: The UNT Digital Library
81891 - A New Class of Solvents for TRU Dissolution and Separation: Ionic Liquids (open access)

81891 - A New Class of Solvents for TRU Dissolution and Separation: Ionic Liquids

Through the current EMSP funding, solvent extraction technologies based on liquid-liquid partitioning of TRU to an Ionic Liquid phase containing conventional complexants has been shown to be viable. The growing understanding of the role that the different components of an ionic liquid can have on the partitioning mechanism, and on the nature of the subsequent dissolved species indicates strongly that ionic liquids are not necessarily direct replacements for volatile or otherwise hazardous organic solvents. Separations and partitioning can be exceptionally complex with competing solvent extraction, cation, anion and sacrificial ion exchange mechanisms are all important, depending on the selection of components for formation of the ionic liquid phase, and that control of these competing mechanisms can be utilized to provide new, alternative separations schemes.
Date: December 10, 2004
Creator: Rogers, Robin D.
Object Type: Report
System: The UNT Digital Library
Acceleration of Polarized Beams Using Multiple Strong Partial Siberian Snakes (open access)

Acceleration of Polarized Beams Using Multiple Strong Partial Siberian Snakes

Acceleration of polarized protons in the energy range of 5 to 25 GeV is particularly difficult since depolarizing spin resonances are strong enough to cause significant depolarization but full Siberian snakes cause intolerably large orbit excursions. Using a 20-30% partial Siberian snake both imperfection and intrinsic resonances can be overcome. Such a strong partial Siberian snake was designed for the Brookhaven AGS using a dual pitch helical superconducting dipole. Multiple strong partial snakes are also discussed for spin matching at beam injection and extraction.
Date: October 10, 2004
Creator: Roser, T.; Ahrens, L.; Bai, M.; Courant, E.; Glenn, J. W.; Gupta, R. C. et al.
Object Type: Article
System: The UNT Digital Library
Adaptations of the Purge Water Management System for Long-Term Groundwater Monitoring at Savannah River Site, South Carolina (final) (open access)

Adaptations of the Purge Water Management System for Long-Term Groundwater Monitoring at Savannah River Site, South Carolina (final)

To monitor the groundwater contamination and the effectiveness of remedial actions, over a thousand monitoring wells are in active operation (i.e., require quarterly or semi-annual sampling) at SRS. Most wells are expected to continue in operation for another 20 to 40 more years. Required sample volumes can range from a less than a liter to 10 liters. To support the long-term groundwater monitoring requirements of these wells, SRS actively seeks technologies that can maximize data acquisition and minimize costs. To meet this end, SRS has implemented the Purge Water Management System (PWMS). The key attributes of this system lie in its ability to reduce or eliminate the generation of purged groundwater, which is costly in terms of the time and management.
Date: February 10, 2004
Creator: Schiefer, E
Object Type: Article
System: The UNT Digital Library
AGING FACILITY CRITICALITY SAFETY CALCULATIONS (open access)

AGING FACILITY CRITICALITY SAFETY CALCULATIONS

The purpose of this design calculation is to revise and update the previous criticality calculation for the Aging Facility (documented in BSC 2004a). This design calculation will also demonstrate and ensure that the storage and aging operations to be performed in the Aging Facility meet the criticality safety design criteria in the ''Project Design Criteria Document'' (Doraswamy 2004, Section 4.9.2.2), and the functional nuclear criticality safety requirement described in the ''SNF Aging System Description Document'' (BSC [Bechtel SAIC Company] 2004f, p. 3-12). The scope of this design calculation covers the systems and processes for aging commercial spent nuclear fuel (SNF) and staging Department of Energy (DOE) SNF/High-Level Waste (HLW) prior to its placement in the final waste package (WP) (BSC 2004f, p. 1-1). Aging commercial SNF is a thermal management strategy, while staging DOE SNF/HLW will make loading of WPs more efficient (note that aging DOE SNF/HLW is not needed since these wastes are not expected to exceed the thermal limits form emplacement) (BSC 2004f, p. 1-2). The description of the changes in this revised document is as follows: (1) Include DOE SNF/HLW in addition to commercial SNF per the current ''SNF Aging System Description Document'' (BSC 2004f). (2) Update …
Date: September 10, 2004
Creator: Sanders, C.E.
Object Type: Report
System: The UNT Digital Library
Alternatives to Seesaw (open access)

Alternatives to Seesaw

The seesaw mechanism is attractive not only because it"explains'' small neutrino mass, but also because of its packaging with the SUSY-GUT, leptogenesis, Dark Matter, and electroweak symmetry breaking. However, this package has the flavor, CP, and gravitino problems. I discuss two alternatives to the seesaw mechanism. In one of them, the anomaly-mediated supersymmetry breaking solves these problems, while predicts naturally light Dirac neutrinos. In the other, the light Majorana neutrinos arise from supersymmetry breaking with right-handed neutrinos below TeV, and the Dark Matter and collider phenomenology are significantly different.
Date: October 10, 2004
Creator: Murayama, Hitoshi
Object Type: Article
System: The UNT Digital Library
Annual Change Report 2003/2004 (open access)

Annual Change Report 2003/2004

As part of continuing compliance, the U.S. Environmental Protection Agency (EPA) requires the U.S. Department of Energy (DOE) to provide any change in information since the most recent compliance application. This requirement is identified in Title 40 Code of Federal Regulations (CFR), Section 194.4(b)(4), which states: “No later than six months after the administrator issues a certification, and at least annually thereafter, the Department shall report to the Administrator, in writing, any changes in conditions or activities pertaining to the disposal system that were not required to be reported by paragraph (b)(3) of this section and that differ from information contained in the most recent compliance application.” In meeting the requirement, the DOE provides an annual report of all changes applicable under the above requirement each November. This annual report informs the EPA of changes to information in the most recent compliance application, or for this report the 1996 Compliance Certification Application (CCA). Significant planned changes must be reported to the EPA prior to implementation by the DOE. In addition, Title 40 CFR, Section 194.4(b)(3) requires that significant unplanned changes be reported to the EPA within 24 hours or ten days, depending on the severity of the activity or condition. …
Date: November 10, 2004
Creator: Washington Regulatory and Environmental Services
Object Type: Report
System: The UNT Digital Library
Application and Development of Appropriate Tools and Technologies for Cost-Effective Carbon Sequestration (open access)

Application and Development of Appropriate Tools and Technologies for Cost-Effective Carbon Sequestration

The Nature Conservancy is participating in a Cooperative Agreement with the Department of Energy (DOE) National Energy Technology Laboratory (NETL) to explore the compatibility of carbon sequestration in terrestrial ecosystems and the conservation of biodiversity. The title of the research project is ''Application and Development of Appropriate Tools and Technologies for Cost-Effective Carbon Sequestration''. The objectives of the project are to: (1) improve carbon offset estimates produced in both the planning and implementation phases of projects; (2) build valid and standardized approaches to estimate project carbon benefits at a reasonable cost; and (3) lay the groundwork for implementing cost-effective projects, providing new testing ground for biodiversity protection and restoration projects that store additional atmospheric carbon. This Technical Progress Report discusses preliminary results of the six specific tasks that The Nature Conservancy is undertaking to answer research needs while facilitating the development of real projects with measurable greenhouse gas impacts. The research described in this report occurred between July 1, 2002 and June 30, 2003. The specific tasks discussed include: Task 1: carbon inventory advancements; Task 2: remote sensing for carbon analysis; Task 3: baseline method development; Task 4: third-party technical advisory panel meetings; Task 5: new project feasibility studies; and …
Date: July 10, 2004
Creator: Stanley, Bill; Brown, Sandra; Gonzalez, Patrick; Kant, Zoe; Tiepolo, Gilberto; Sabido, Wilber et al.
Object Type: Report
System: The UNT Digital Library
Assessment of ICRF Antenna Performance in Alcator C-Mod (open access)

Assessment of ICRF Antenna Performance in Alcator C-Mod

The Alcator C-Mod has presented a challenge to install high-power ICRF antennas in a tight space. Modifications have been made to the antenna plasma-facing surfaces and the internal current-carrying structure in order to overcome performance limitations. At the present time, the antennas have exceeded 5 MW into plasma with heating phasing, up to 2.7 MW with current-drive phasing, with good efficiency and no deleterious effects
Date: August 10, 2004
Creator: Schilling, G.; Wukitch, S. J.; Lin, Y.; Basse, N.; Bonoli, P. T.; Edlund, E. et al.
Object Type: Report
System: The UNT Digital Library
B Physics at the Tevatron (open access)

B Physics at the Tevatron

After a five year upgrade period, the Fermilab experiments CDF and D0 are taking high quality data in Run II of the Tevatron Collider. We report on the start-up of both detectors and present a selection of first B physics results from the Tevatron. We also compare different B hadron producers such as the {Upsilon}(4S) with the hadron collider environment and discuss general features of B physics at a hadron collider.
Date: February 10, 2004
Creator: Paulini, Manfred
Object Type: Article
System: The UNT Digital Library
BEAM DUMP WINDOW DESIGN FOR THE SPALLATION NEUTRON SOURCE. (open access)

BEAM DUMP WINDOW DESIGN FOR THE SPALLATION NEUTRON SOURCE.

The Spallation Neutron Source accelerator systems will provide a 1 GeV, 1.44 MW proton beam to a liquid mercury target for neutron production. Beam tuning dumps are provided at the end of the linac (the Linac Dump) and in the Ring-to-Target transport line (the Extraction Dump) [1]. Thin windows are required to separate the accelerator vacuum from the poor vacuum upstream of the beam dump. There are several challenging engineering issues that have been addressed in the window design. Namely, handling of the high local power density deposited by the stripped electrons from the H-beam accelerated in the linac, and the need for low-exposure removal and replacement of an activated window. The thermal design of the linac dump window is presented, as is the design of a vacuum clamp and mechanism that allows remote removal and replacement of the window.
Date: March 10, 2004
Creator: RAPARIA,D. RANK,J. MURDOCH,G. ET AL.
Object Type: Article
System: The UNT Digital Library
Brightness Optimization of Ultra-Fast Thomson Scattering X-ray Sources (open access)

Brightness Optimization of Ultra-Fast Thomson Scattering X-ray Sources

We present simple scaling relations of the brightness a Thomson x-ray source on the electron and laser beam parameters in the case of a head (180 degree) interaction geometry. In particular, it is shown that a direct relation exists between the x-ray brightness and the electron beam brightness. These relations are discussed in the context of the PLEIADES Thomson x-ray source, where 10{sup 7} photons per pulse, with photon energies as high as 140 keV, have been produced by colliding a 0.25 nC, picosecond electron bunch with a 500 mJ, 50 fs, 800 nm laser pulse. The estimated peak brightness of the source is about 10{sup 16} photons/s/mm{sup 2}/mrad{sup 2}/0.1%b.w. A comparison of the current performance of the source and the predicted performance using optimized parameters is presented.
Date: August 10, 2004
Creator: Brown, W J & Hartemann, F V
Object Type: Article
System: The UNT Digital Library
CALCULATIONS OF SINGLE-INCLUSIVE CROSS SECTIONS AND SPIN ASYMMETRIES IN PP SCATTERING. (open access)

CALCULATIONS OF SINGLE-INCLUSIVE CROSS SECTIONS AND SPIN ASYMMETRIES IN PP SCATTERING.

We present calculations of cross sections and spin asymmetries in single-inclusive reactions in, pp scattering. We discuss next-to-leading order predictions as well as all-order soft-gluon 'threshold' resummations.
Date: October 10, 2004
Creator: Vogelsang, W.
Object Type: Article
System: The UNT Digital Library
Canted Undulator Front-End Exit-Mask Flow-Induced Vibration Measurements. (open access)

Canted Undulator Front-End Exit-Mask Flow-Induced Vibration Measurements.

All of the high-heat-load critical components in the new canted-undulator front-end (CU FE) design use wire-coil inserts inside of the cooling channels to significantly enhance heat transfer. Wire-coil inserts have replaced the copper-mesh inserts used in previous front-end high-heat-load critical-component designs. The exit mask, the most downstream component in the CU FE line relative to the x-ray beam path, has an exit aperture of 2 mm vertical x 3 mm horizontal and is the most sensitive component, in terms of final beam stability, of all of the CU FE components. In general, final beam stability is determined by the storage-ring output-beam stability and not by the CU FE components. Although front-end components are not very sensitive to vibration, several measurements have been performed to assess the flow-induced vibration associated with the CU FE exit mask. Results yield only 0.16 {micro}mrms vertical displacement and 1.0 {micro}mrms horizontal displacement under worst-case conditions. The maximum displacement values are very small compared to the aperture size, and therefore flow-induced vibration has a negligible effect on the CU FE output beam stability. More general measurements have also been performed to directly compare flow-induced vibration in an open, unrestricted tube relative to the same tube containing …
Date: November 10, 2004
Creator: Collins, J.; Doose, C. L.; Attig, J. N. & Baehl, M. M.
Object Type: Report
System: The UNT Digital Library
Cathodoluminescence Microanalysis of the Distribution of defects induced in fused silica by UV laser pulses and after damage mitigation treatment with a CO2 laser (open access)

Cathodoluminescence Microanalysis of the Distribution of defects induced in fused silica by UV laser pulses and after damage mitigation treatment with a CO2 laser

Point defects are induced in high quality optical-grade fused silica by high fluence (>30 J/cm{sup 2}) 355nm laser pulses. The microscopic depth distribution of laser irradiation induced defects has been nondestructively determined using Cathodoluminescence (CL) microanalysis. CL emissions have been observed at 1.9eV, 2.2eV, 2.7eV and 4.4eV. In addition following CO{sup 2} laser treatment for damage mitigation an emission at 3.2eV is also observed. The CL emissions have been identified with the NBOHC (non-bridging oxygen hole center), the STE (self-trapped exciton), an ODC (oxygen-deficient center) and an aluminum impurity centre. The spatially resolved CL data is consistent with damage initiation at the exit surface. The concentration of 355 nm laser induced defects is greatest at the surface and monotonically decays to pre-irradiation levels at {approx}10 {micro}m depth below the surface. With CO{sup 2} processing to mitigate damage, the defect concentration and spatial distribution is reduced to a maximum depth of {approx}6{micro}m. CL microanalysis provides a sensitive and nondestructive method of assessing the magnitude and submicron distribution of irradiation induced damage in technologically important materials.
Date: March 10, 2004
Creator: Stevens-Kalceff, M & Wong, J
Object Type: Article
System: The UNT Digital Library
China's sustainable energy future: Scenarios of energy and carbonemissions (Summary) (open access)

China's sustainable energy future: Scenarios of energy and carbonemissions (Summary)

China has ambitious goals for economic development, and mustfind ways to power the achievement of those goals that are bothenvironmentally and socially sustainable. Integration into the globaleconomy presents opportunities for technological improvement and accessto energy resources. China also has options for innovative policies andmeasures that could significantly alter the way energy is acquired andused. These opportunities andoptions, along with long-term social,demographic, and economic trends, will shape China s future energysystem, and consequently its contribution to emissions of greenhousegases, particularly carbon dioxide (CO2). In this study, entitled China sSustainable Energy Future: Scenarios of Energy and Carbon Emissions, theEnergy Research Institute (ERI), an independent analytic organizationunder China's Na tional Development and Reform Commission (NDRC), soughtto explore in detail how China could achieve the goals of the TenthFive-Year Plan and its longer term aims through a sustainable developmentstrategy. China's ability to forge a sustainable energy path has globalconsequences. China's annual emissions of greenhouse gases comprisenearly half of those from developing countries, and 12 percent of globalemissions. Most of China's greenhouse gas emissions are in the form ofCO2, 87 percent of which came from energy use in 2000. In that year,China's carbon emissions from energy use and cement production were 760million metric tons (Mt-C), …
Date: March 10, 2004
Creator: Zhou, Dadi; Levine, Mark; Dai, Yande; Yu, Cong; Guo, Yuan; Sinton, Jonathan E. et al.
Object Type: Report
System: The UNT Digital Library
THE COMMISSIONING PLAN FOR THE SPALLATION NEUTRON SOURCE RING AND TRANSPORT LINES. (open access)

THE COMMISSIONING PLAN FOR THE SPALLATION NEUTRON SOURCE RING AND TRANSPORT LINES.

The Spallation Neutron Source (SNS) accelerator systems will provide a 1 GeV, 1.44 MW proton beam to a liquid mercury target for neutron production. In order to satisfy the accelerator systems' portion of the Critical Decision 4 (CD-4) commissioning goal (which marks the completion of the construction phase of the project), a beam pulse with intensity greater than 1 x 10{sup 13} protons must be accumulated in the ring, extracted in a single turn and delivered to the target. A commissioning plan has been formulated for bringing into operation and establishing nominal operating conditions for the various ring and transport line subsystems as well as for establishing beam conditions and parameters which meet the commissioning goal.
Date: March 10, 2004
Creator: RAPARIA,D. BLASKIEWICZ,M. LEE,Y. Y. WEI,J. ET AL.
Object Type: Article
System: The UNT Digital Library
Comparing Shape and Texture Features for Pattern Recognition in Simulation Data (open access)

Comparing Shape and Texture Features for Pattern Recognition in Simulation Data

Shape and texture features have been used for some time for pattern recognition in datasets such as remote sensed imagery, medical imagery, photographs, etc. In this paper, we investigate shape and texture features for pattern recognition in simulation data. In particular, we explore which features are suitable for characterizing regions of interest in images resulting from fluid mixing simulations. Three texture features--gray level co-occurrence matrices, wavelets, and Gabor filters--and two shape features--geometric moments and the angular radial transform--are compared. The features are evaluated using a similarity retrieval framework. Our preliminary results indicate that Gabor filters perform the best among the texture features and the angular radial transform performs the best among the shape features. The feature which performs the best overall is dependent on how the groundtruth dataset is created.
Date: December 10, 2004
Creator: Newsam, S & Kamath, C
Object Type: Article
System: The UNT Digital Library
Comparison and Evaluation of Various Tritium Decontamination Techniques and Processes (open access)

Comparison and Evaluation of Various Tritium Decontamination Techniques and Processes

In support of fusion energy development, various techniques and processes have been developed over the past two decades for the removal and decontamination of tritium from a variety of items, surfaces, and components. Tritium decontamination, by chemical, physical, mechanical, or a combination of these methods, is driven by two underlying motivational forces. The first of these motivational forces is safety. Safety is paramount to the established culture associated with fusion energy. The second of these motivational forces is cost. In all aspects, less tritium contamination equals lower operational and disposal costs. This paper will discuss and evaluate the various processes employed for tritium removal and decontamination.
Date: September 10, 2004
Creator: Gentile, C. A.; Langish, S. W.; Skinner, C. H. & Ciebiera, L. P.
Object Type: Report
System: The UNT Digital Library