Results of Deposition Scoping Tests (open access)

Results of Deposition Scoping Tests

The processes of crystallization and solid deposit formation that led to the shutdown of the 2H evaporator operation at the Savannah River Site (SRS) and that could possibly cause similar problems in the future or in other evaporators need to be better understood. Through experimentation, thermodynamic modeling, and correlation of scaling to historical tank farm operations, progress has been made in developing guidelines as to the concentrations of silicon and aluminum that can be processed by evaporators while avoiding unacceptable levels of scale formation. However, because of limitations of the thermodynamic model and an insufficient amount of operational data at slightly supersaturated concentration levels, uncertainty still exists regarding acceptable feed concentrations. The objective of this effort is to provide information that can be used in defining acceptable levels of silicon and aluminum in evaporator feed solutions. Data collected previously showed that particle formation reactions can be rapid at evaporator temperatures for elevated silicon and aluminum concentrations. However, insufficient data exists to estimate the silicon and aluminum concentrations above which solids will form in the time frame of evaporator processing. The work described in this report was designed to determine the induction period for solutions of decreasing aluminum and silicon concentration …
Date: March 4, 2003
Creator: Hu, M.Z.
Object Type: Report
System: The UNT Digital Library
Ab Initio Nuclear Structure from Helium to Oxygen Final Report: 00-ERD-028 (open access)

Ab Initio Nuclear Structure from Helium to Oxygen Final Report: 00-ERD-028

Final report for a research program in theoretical nuclear physics to develop methods and computer programs to perform ab initio calculations for light nuclei ranging from Helium to Oxygen. The method employed is based effective interaction theory within the framework of the shell model. The principal accomplishments were: (1) participation in the validation of ab initio for {sup 4}He; the first study of A = 6 nuclei with the realistic, non-local CD-Bonn potential; (2) a study of ''intruder'' states in {sup 8}Be, (3) the first shell-model calculations implementing three-body clusters in the effective interaction for nuclei with A > 4; (4) the discovery that two-nucleon interactions by themselves are inadequate to describe the structure of the nucleus {sup 10}B, which provides proof that three-nucleon forces affect nuclear structure; (5) first calculations including the Tucson-Melbourne three-nucleon force, which gives better agreement with the experimental spectrum for {sup 10}B and (6) the development of a new shell-model code designed for public release.
Date: February 4, 2003
Creator: Ormand, W E & Navratil, P
Object Type: Report
System: The UNT Digital Library
Interferometric Studies of Laser-Created Plasmas Using Compact Soft X-Ray Lasers (open access)

Interferometric Studies of Laser-Created Plasmas Using Compact Soft X-Ray Lasers

We summarize results of several successful dense plasma diagnostics experiments realized by combining two different kinds of table-top soft x-ray lasers with an amplitude division interferometer based on diffraction grating beam splitters. In the first set of experiments this robust high throughput diffraction grating interferometer (DGI) was used with a 46.9 nm portable capillary discharge laser to study the dynamics of line focus and point focus laser-created plasmas. The measured electron density profiles, which differ significantly from those expected from a classical expansion, unveil important two-dimensional effects of the dynamics of these plasmas. A second DGI customized to operate in combination with a 14.7 nm Ni-like Pd transient gain laser was used to perform interferometry of line focus laser-created plasmas with picosecond time resolution. These measurements provide valuable new benchmarks for complex hydrodynamic codes and help bring new understanding of the dynamics of dense plasmas. The instrumentation and methodology we describe is scalable to significantly shorter wavelengths, and constitutes a promising scheme for extending interferometry to the study of very dense plasmas such as those investigated for inertial confinement fusion.
Date: December 4, 2003
Creator: Dunn, J.; Nilsen, J.; Moon, S.; Keenan, R.; Jankowska, E.; Maconi, M. C. et al.
Object Type: Article
System: The UNT Digital Library
Surface-Enhanced Raman Spectroscopy with High Spatial Resolution (open access)

Surface-Enhanced Raman Spectroscopy with High Spatial Resolution

The identification of individual molecules and the determination of how these interact with their local environment are critical steps toward a better understanding of complex organic systems. Optical detection techniques have always played a key role in the nondestructive and noninvasive analysis of complex materials. Until recently, however, optical microscopy has lacked the sensitivity to study processes on the molecular scale. This has changed with the recent development of new schemes that limit the optical detection volume, and the advent of new, highly quantum-efficient photon detectors. These inventions have enabled researchers to optically probe biomolecular processes at the single molecule level by observing the fluorescence of specific marker molecules. The requirement to specifically label biomolecules and the fact, that fluorescence emission is prone to photodecomposition of the marker molecules, however, have limited this approach to a few, well-characterized case studies. Raman scattering, is one of few optical techniques that can identify atomic species and in addition determine their chemical bonds by observing their distinct vibrational fingerprints; but it is orders of magnitude weaker than fluorescence. In this project, we have developed new optical probes that allow for the non-destructive characterization and identification of organic and inorganic matter at the single …
Date: February 4, 2003
Creator: Huser, T R
Object Type: Report
System: The UNT Digital Library
Effect of Structural Modification on Second Harmonic Generation in Collagen (open access)

Effect of Structural Modification on Second Harmonic Generation in Collagen

The effects of structural perturbation on second harmonic generation in collagen were investigated. Type I collagen fascicles obtained from rat tails were structurally modified by increasing nonenzymatic cross-linking, by thermal denaturation, by collagenase digestion, or by dehydration. Changes in polarization dependence were observed in the dehydrated samples. Surprisingly, no changes in polarization dependence were observed in highly crosslinked samples, despite significant alterations in packing structure. Complete thermal denaturation and collagenase digestion produced samples with no detectable second harmonic signal. Prior to loss of signal, no change in polarization dependence was observed in partially heated or digested collagen.
Date: April 4, 2003
Creator: Stoller, P C; Reiser, K M; Celliers, P M & Rubenchik, A M
Object Type: Article
System: The UNT Digital Library
High Current Ion Source Development for Heavy Ion Fusion (open access)

High Current Ion Source Development for Heavy Ion Fusion

We are developing high-current-density high-brightness sources for Heavy Ion Fusion applications. Heavy ion driven inertial fusion requires beams of high brightness in order to achieve high power density at the target for high target gain. At present, there are no existing ion source types that can readily meet all the driver HIF requirements, though sources exist which are adequate for present experiments and which with further development may achieve driver requirements. Our two major efforts have been on alumino-silicate sources and RF plasma sources. Experiments being performed on a 10-cm alumino-silicate source are described. To obtain a compact system for a HIF driver we are studying RF plasma sources where low current beamlets are combined to produce a high current beam. A 80-kV 20-{micro}s source has produced up to 5 mA of Ar{sup +} in a single beamlet. The extraction current density was 100 mA/cm{sup 2}. We present measurements of the extracted current density as a function of RF power and gas pressure, current density uniformity, emittance, and energy dispersion (due to charge exchange).
Date: September 4, 2003
Creator: Westenskow, G A; Grote, D P & Kwan, J W
Object Type: Article
System: The UNT Digital Library
Science and Technology in Support of U.S. Policy in Central Asia (open access)

Science and Technology in Support of U.S. Policy in Central Asia

The current war with Iraq, international interventions in Afghanistan, and the continuous and seemingly insolvable problems in the Middle East emphasize the importance of supporting stable, healthy countries throughout the Middle East and South and Central Asia. The political alliances and foreign aid promulgated by the Cold War have been seriously strained, creating a more uncertain and unstable international environment. We must stay engaged with this part of the world. New partnerships must be forged. Central Asia represents a mix of political systems - from totalitarian rule to nascent democracy; of economic resources from natural to human; and of cultures from ancient to modern - making it of strategic importance to U. S. national and economic security. The U.S. must remain committed and proactively engaged in the region to promote open and democratic societies attractive to outside investment and to prevent the proliferation of weapons of mass destruction and extremist groups. The U.S is admired for its science and technology and its flexibility in innovation and applying S&T to solve problems. The inherent value that S&T can contribute to advancing U.S. policy goals is the underlying assumption of this report. Science and technology and their applications have much to contribute …
Date: November 4, 2003
Creator: Knapp, R B
Object Type: Article
System: The UNT Digital Library
Weldability of Fe-Al-Cr Overlay Coatings for CorrosionProtection in Oxidizing/Sulfidizing Environments (open access)

Weldability of Fe-Al-Cr Overlay Coatings for CorrosionProtection in Oxidizing/Sulfidizing Environments

The effect of chromium additions to the weldability of Fe-Al based overlay claddings are currently being investigated for the corrosion protection of boiler tubes in Low NOx furnaces. The primary objective of this research is to identify weldable (crack-free) Fe-Al-Cr weld overlay coating compositions that provide corrosion resistance over long exposure times. During the current project phase, preliminary corrosion testing was conducted on several ternary Fe-Al-Cr alloys in two types of gaseous corrosion environments. These long-term corrosion tests were used to develop a target weld composition matrix and serve as a base line for future corrosion tests. Preliminary Fe-Al based welds with various aluminum concentrations and one ternary Fe-Al-Cr weld overlay were successfully deposited using a Gas Tungsten Arc Welding (GTAW) process and cracking susceptibility was evaluated on these coatings.
Date: March 4, 2003
Creator: Regina, JR
Object Type: Report
System: The UNT Digital Library
Alaska Oil and Gas Exploration, Development, and Permitting Project (open access)

Alaska Oil and Gas Exploration, Development, and Permitting Project

The objective of this project is to eliminate three closely inter-related barriers to oil production in Alaska through the use of a geographic information system (GIS) and other information technology strategies. These barriers involve identification of oil development potential from existing wells, planning projects to efficiently avoid conflicts with other interests, and gaining state approvals for exploration and development projects. Each barrier is the result of either current labor-intensive methods or poorly accessible information. This project brings together three parts of the oil exploration, development, and permitting process to form the foundation for a more fully integrated information technology infrastructure for the State of Alaska. This web-based system will enable the public and other review participants to track permit status, submit and view comments, and obtain important project information online. By automating several functions of the current manual process, permit applications will be completed more quickly and accurately, and agencies will be able to complete reviews with fewer delays. The application will include an on-line diagnostic Coastal Project Questionnaire to determine the suite of permits required for a specific project. The application will also automatically create distribution lists based on the location and type of project, populate document templates for …
Date: August 4, 2003
Creator: McMahon, Richard; Crandall, Robert; Dense, Chas & Weems, Sean
Object Type: Report
System: The UNT Digital Library
Improvement to Pipeline Compressor Engine Reliability Through Retrofit Micro-Pilot Ignition System-Phase I (open access)

Improvement to Pipeline Compressor Engine Reliability Through Retrofit Micro-Pilot Ignition System-Phase I

This report documents the first year's effort towards a 3-year program to develop micropilot ignition systems for existing pipeline compressor engines. In essence, all Phase I goals and objectives were met. We intend to proceed with the Phase II research plan, as set forth by the applicable Research Management Plan. The objective for Phase I was to demonstrate the feasibility of micropilot ignition for large bore, slow speed engines operating at low compression ratios. The primary elements of Micropilot Phase I were to develop a single-cylinder test chamber to study the injection of pilot fuel into a combustion cylinder and to develop, install and test a multi-cylinder micropilot ignition system for a 4-cylinder, natural gas test engine. In all, there were twelve (12) tasks defined and executed to support these two (2) primarily elements in a stepwise fashion. Task-specific approaches and results are documented in this report. Research activities for Micropilot Phase I were conducted with the understanding that the efforts are expected to result in a commercial product to capture and disseminate the efficiency and environmental benefits of this new technology. An extensive state-of-art review was conducted to leverage the existing body of knowledge of micropilot ignition with respect …
Date: March 4, 2003
Creator: Bestor, Ted
Object Type: Report
System: The UNT Digital Library
A fast inversion method for interpreting borehole electromagnetic data (open access)

A fast inversion method for interpreting borehole electromagnetic data

None
Date: March 4, 2003
Creator: Kim, Hee Joon; Lee, Ki Ha & Wilt, Michael
Object Type: Article
System: The UNT Digital Library
A RESOLUTION ANALYSIS OF TWO GEOPHYSICAL IMAGING METHODS FOR CHARACTERIZING AND MONITORING HYDROLOGIC CONDITIONS IN THE VADOSE ZONE (open access)

A RESOLUTION ANALYSIS OF TWO GEOPHYSICAL IMAGING METHODS FOR CHARACTERIZING AND MONITORING HYDROLOGIC CONDITIONS IN THE VADOSE ZONE

The objective of this study is to characterize and analyze in-situ flow and transport within the vadose zone during a mid-scale hydrologic infiltration experiment. This project has employed numerical and experimental tools developed under a previously funded EMSP proposal (project number 55332) to provide 3-D unsaturated hydrologic property distributions. In the present project, geophysical imaging techniques have been employed to track analogue contaminant plumes. The results are providing a better understanding of transport modes including the influence of natural heterogeneities and man-made structures within the vadose zone at DOE sites. In addition the data is providing checks against which numerical flow and transport simulations can be compared
Date: June 4, 2003
Creator: Alumbaugh, David L. & Brainard, James R.
Object Type: Report
System: The UNT Digital Library
ADVANCED TECHNOLOGIES FOR STRIPPER GAS WELL ENHANCEMENT (open access)

ADVANCED TECHNOLOGIES FOR STRIPPER GAS WELL ENHANCEMENT

As part of Task 1 in Advanced Technologies for Stripper Gas Well Enhancement, Schlumberger Data & Consulting Services (DCS) joined with two Appalachian Basin producers, Great Lakes Energy Partners, LLC, and Belden & Blake Corporation to develop methodologies for identification and enhancement of stripper wells with economic upside potential. These industry partners previously provided us with data for more than 700 wells in northwestern Pennsylvania. Phase 1 goals of this project are to develop and validate methodologies that can quickly and cost-effectively identify wells with enhancement potential. We have enhanced and streamlined our software, and we are using the final version of our new Microsoft{trademark} Access/Excel programs. During the last quarter of 2002, we received additional data for approximately 2,200 wells from Great Lakes. This information pertains to their Cooperstown field located in northwestern Pennsylvania. We recognized approximately 130 potential remediation candidates, and Great Lakes' personnel are currently reviewing this list for viable remediation. This field has provided a rigorous test of our software and analytical methods. We have processed all the information provided to us including the Cooperstown data. Great Lakes also provided supplemental data listing the original operator of the wells. We have determined whether a statistically significant …
Date: April 4, 2003
Creator: MacDonald, Ronald J.
Object Type: Report
System: The UNT Digital Library
Field Test Program to Develop Comprehensive Design, Operating and Cost Data for Mercury Control Systems on Non-Scrubbed Coal-Fired Boilers, Quarterly Technical Report: July-September 2003 (open access)

Field Test Program to Develop Comprehensive Design, Operating and Cost Data for Mercury Control Systems on Non-Scrubbed Coal-Fired Boilers, Quarterly Technical Report: July-September 2003

With the Nation's coal-burning utilities facing the possibility of tighter controls on mercury pollutants, the U.S. Department of Energy is funding projects that could offer power plant operators better ways to reduce these emissions at much lower costs. Mercury is known to have toxic effects on the nervous system of humans and wildlife. Although it exists only in trace amounts in coal, mercury is released when coal burns and can accumulate on land and in water. In water, bacteria transform the metal into methylmercury, the most hazardous form of the metal. Methylmercury can collect in fish and marine mammals in concentrations hundreds of thousands times higher than the levels in surrounding waters. One of the goals of DOE is to develop technologies by 2005 that will be capable of cutting mercury emissions 50 to 70 percent at well under one-half of today's costs. ADA Environmental Solutions (ADA-ES) is managing a project to test mercury control technologies at full scale at four different power plants from 2000-2003. The ADA-ES project is focused on those power plants that are not equipped with wet flue gas desulfurization systems. ADA-ES has developed a portable system that will be tested at four different utility power …
Date: November 4, 2003
Creator: Schlager, Richard & Millar, Tom
Object Type: Report
System: The UNT Digital Library
Analysis of Geochemical Data for the Unsaturated Zone (open access)

Analysis of Geochemical Data for the Unsaturated Zone

None
Date: June 4, 2003
Creator: Dixon, P.
Object Type: Report
System: The UNT Digital Library
Effect of ion mass and charge state on transport of vacuum ARC plasmas through a biased magnetic filter (open access)

Effect of ion mass and charge state on transport of vacuum ARC plasmas through a biased magnetic filter

The effect of ion mass and charge state on plasma transport through a 90{sup o}-curved magnetic filter is experimentally investigated using a pulsed cathodic arc source. Graphite, copper, and tungsten were selected as test materials. The filter was a bent copper coil biased via the voltage drop across a low-ohm, ''self-bias'' resistor. Ion transport is accomplished via a guiding electric field, whose potential forms a ''trough'' shaped by the magnetic guiding field of the filter coil. Evaluation was done by measuring the filtered ion current and determination of the particle system coefficient, which can be defined as the ratio of filter ion current, divided by the mean ion charge state, to the arc current. It was found that the ion current and particle system coefficient decreased as the mass-to-charge ratio of ions increased. This result can be qualitatively interpreted by a very simply model of ion transport that is based on compensation of the centrifugal force by the electric force associated with the guiding potential trough.
Date: September 4, 2003
Creator: Byon, Eungsun; Kim, Jong-Kuk; Kwon, Sik-Chol & Anders, Andre
Object Type: Article
System: The UNT Digital Library
The Moeller luminosity factor (open access)

The Moeller luminosity factor

None
Date: August 4, 2003
Creator: Furman, M. A.
Object Type: Report
System: The UNT Digital Library
Impact of Siphoning Activity and Naturally Suspended Particle Load on Mussel Kill by Pseudomonas Fluorescens Quarterly Report (open access)

Impact of Siphoning Activity and Naturally Suspended Particle Load on Mussel Kill by Pseudomonas Fluorescens Quarterly Report

Under this USDOE-NETL contract, the bacterium Pseudomonas fluorescens is being developed as a biocontrol agent for zebra mussels. The specific purpose of the contract is to identify biotic and abiotic factors that affect mussel kill. Ingestion of these bacteria by zebra mussels is required to achieve kill, and tests evaluating factors that relate to mussel feeding are contained in this report. Specifically the impact of the following two factors were investigated: (1) Mussel siphoning behavior--In nature, zebra mussels typically have their two shells spread apart and their inhalant siphon tube extended from between their shells for taking food particles into their mantle cavities (Fig. 1). Our tests indicated that there is a direct correlation between mussel siphoning activity and mussel mortality achieved by a bacterial treatment. Therefore, to encourage mussel feeding on bacteria, future pipe treatments within power plants should be carried out using procedures which minimize disturbance to mussel siphoning. 2. Naturally suspended particle loads--Since bacterial cells are lethal only if ingested by mussels, waters containing very high levels of naturally suspended particles might reduce the mortality that can be achieved by a bacterial treatment. If true, this inhibition might occur as a result of particle exclusion, i.e., there …
Date: August 4, 2003
Creator: Molloy, Daniel
Object Type: Report
System: The UNT Digital Library
Regional cooperation in energy efficiency standard-setting and labeling in North America (open access)

Regional cooperation in energy efficiency standard-setting and labeling in North America

The North American Energy Working Group (NAEWG) was established in 2001 by the governments of Canada, Mexico, and the United States. The goals of NAEWG are to foster communication and cooperation on energy-related matters of common interest, and to enhance North American energy trade and interconnections consistent with the goal of sustainable development, for the benefit of all three countries. At its outset, NAEWG established teams to address different aspects of the energy sector. One, the Energy Efficiency Expert Group, undertook activity in three areas: (1) analyzing commonalities and differences in the test procedures of Canada, Mexico, and the United States, and identifying specific products for which the three countries might consider harmonization; (2) exploring possibilities for increased mutual recognition of laboratory test results; and (3) looking at possibilities for enhanced cooperation in the Energy Star voluntary endorsement labeling program. To support NAEWG's Expert Group on Energy Efficiency (NAEWG-EE), USDOE commissioned Lawrence Berkeley National Laboratory, representing the Collaborative Labeling and Appliance Standards Program (CLASP), to prepare a resource document comparing current standards, labels, and test procedure regulations in Canada, Mexico, and the United States. The resulting document identified 46 energy-using products for which at least one of the three countries …
Date: August 4, 2003
Creator: Wiel, Stephen & Van Wie McGrory, Laura
Object Type: Article
System: The UNT Digital Library
CONVERT 15 WELLS TO BORS PUMPING UNITS AND TEST/COMPARE TO CONVENTIONAL UNITS (open access)

CONVERT 15 WELLS TO BORS PUMPING UNITS AND TEST/COMPARE TO CONVENTIONAL UNITS

A new type of fluid lifting equipment called Balanced Oil Recovery System (trade named BORS Lift{trademark}) was installed on several idle oil wells to demonstrate the operating efficiency of this innovative equipment technology. The BORS Lift system is designed to bring oil to the surface without the accompanying formation water. The BORS Lift system uses an innovative strap mechanism that takes oil from the top of the downhole oilwater column and lifts it to the surface, eliminating production of the formation water. Eliminating salt water production could potentially increase oil production, reduce operational costs, benefit the environment, and cut salt water disposal costs. Although the BORS Lift units did not function as intended, lessons learned during the course of the field demonstration project resulted in improvements in the technology and redesign of subsequent generation BORS Lift units which are reported to have significantly improved their performance characteristics. BORS Lift units were installed on 15 temporarily abandoned wells which had been shut down due to low oil production, high water production, and uneconomic operating conditions. The wells had been producing with artificial lift at a high watercut from a shallow (850-900 feet), pressure depleted oil sand reservoir prior to being shut …
Date: February 4, 2003
Creator: North, Walter B.
Object Type: Report
System: The UNT Digital Library
MICE -- Absorber and focus coil safety working group design document: Preliminary design and assessments (open access)

MICE -- Absorber and focus coil safety working group design document: Preliminary design and assessments

A Neutrino Factory based on a muon storage ring is the ultimate tool for studies of neutrino oscillations, including possibly the discovery of leptonic CP violation. it is also the first step toward a muon collider. To develop a stored-muon-beam facility to serve as a Neutrino Factory, it is necessary to ''cool'' a muon beam (decrease its phase-space volume). The short lifetime of the muon, 2.2 {micro}s at rest, eliminates all currently demonstrated cooling techniques and requires that a new, heretofore untried, technique--ionization cooling--be employed. Although ionization cooling of muons has never been demonstrated in practice, it has been shown by end-to-end simulation and design studies to be an important factor both for the performance and for the cost of a Neutrino Factory. This motivates an international program of R and D, including an experimental demonstration at Rutherford Appleton Laboratory (RAL). The aims of the international Muon Ionization Cooling Experiment are: (1) to show that it is possible to design, engineer and build a section of cooling channel capable of giving the desired performance for a Neutrino Factory; and (2) to place it in a muon beam and measure its performance in various modes of operation and beam conditions, thereby …
Date: December 4, 2003
Creator: Barr, Giles; Baynham, Elwyn; Black, Edgar; Bradshaw, Tom; Cummings, Mary Anne; Green, Michael A. et al.
Object Type: Report
System: The UNT Digital Library
The role of oxygen at screw dislocations in GaN (open access)

The role of oxygen at screw dislocations in GaN

None
Date: September 4, 2003
Creator: Arslan, Ilke & Browning, Nigel D.
Object Type: Article
System: The UNT Digital Library
Advanced Oxidation Process (open access)

Advanced Oxidation Process

The removal of recalcitrant sulfur species, dibenzothiophene and its derivatives, from automotive fuels is an integral component in the development of cleaner burning and more efficient automobile engines. Oxidative desulfurization (ODS) wherein the dibenzothiophene derivative is converted to its corresponding sulfoxide and sulfone is an attractive approach to sulfur removal because the oxidized species are easily extracted or precipitated and filtered from the hydrocarbon phase. Fe-TAML{reg_sign} activators of hydrogen peroxide (TAML is Tetra-Amido-Macrocyclic-Ligand) catalytically convert dibenzothiophene and its derivatives rapidly and effectively at moderate temperatures (50-60 C) and ambient pressure to the corresponding sulfoxides and sulfones. The oxidation process can be performed in both aqueous systems containing alcohols such as methanol, ethanol, or t-butanol, and in a two-phase hydrocarbon/aqueous system containing tert-butanol or acetonitrile. In the biphasic system, essentially complete conversion of the DBT to its oxidized products can be achieved using slightly longer reaction times than in homogeneous solution. Among the key features of the technology are the mild reaction conditions, the very high selectivity where no over oxidation of the sulfur compounds occurs, the near stoichiometric use of hydrogen peroxide, the apparent lack of degradation of sensitive fuel components, and the ease of separation of oxidized products.
Date: November 4, 2003
Creator: Horwitz, Colin P. & Collins, Terrence J.
Object Type: Report
System: The UNT Digital Library
The Advanced Light Source Upgrade (open access)

The Advanced Light Source Upgrade

The ALS, a third-generation synchrotron light source at Berkeley Lab, has been operating for almost a decade and is generating forefront science by exploiting the high brightness of a third-generation source in three areas: (1) high resolving power for spectroscopy; (2) high spatial resolution for microscopy and spectromicroscopy; and (3) high coherence for experiments such as speckle. However, the ALS was one of the first third-generation machines to be designed, and accelerator and insertion-device technology have significantly changed since its conception. As a result, its performance will inevitably be outstripped by newer, more advanced sources. To remain competitive and then set a new standard, the performance of the ALS, in particular its brightness, must be enhanced. Substantial improvements in brightness and current have always been feasible in principle, but they incur the penalty of a much reduced lifetime, which is totally unacceptable to our users. Significant brightness improvements can be realized in the core soft x-ray region by going to top-off operation, where injection would be quasi-continuous and the lifetime objections disappear. In top-off mode with higher average current, a reduced vertical emittance and beta function, and small-gap permanent-magnet or superconducting insertion devices, one to two orders of magnitude improvement …
Date: November 4, 2003
Creator: Chemla, Daniel S.; Feinberg, Benjamin; Hussain, Zahid; Krebs, Gary F.; Padmore, Howard A.; Robin, David S. et al.
Object Type: Article
System: The UNT Digital Library