Bunch shape measurement of CW heavy-ion beam. (open access)

Bunch shape measurement of CW heavy-ion beam.

An accurate bunch shape measurement is one of the most important tasks during the fine tuning of multicavity accelerators. A device for the measurement of bunch time structure of cw heavy-ion beams with time resolution {approx}20 picoseconds was developed, constructed and commissioned at ATLAS which is a 50 MV superconducting heavy-ion linac. The Bunch Shape Monitor (BSM) is based on the analysis of secondary electrons produced by a primary beam hitting a tungsten wire to which a potential of -10 kV is applied. In a BSM the longitudinal distribution of charge of the primary beam is coherently transformed into a spatial distribution of low energy secondary electrons through transverse rf modulation. The distribution of secondary electrons is detected by a chevron MCP coupled to a phosphor screen. The signal image on the screen is measured by use of a CCD camera connected to a PC. This BSM analyzes cw beams rather than pulsed beams studied by a previous device [1]. Design features of the BSM and the beam measurement results are reported.
Date: August 22, 2002
Creator: Vinogradov, N. Y.; Billquist, P.; Ostroumov, P. N.; Pardo, R. C.; Portillo, M.; Sharamentov, S. I. et al.
Object Type: Article
System: The UNT Digital Library
Confidence limits and their errors (open access)

Confidence limits and their errors

Confidence limits are common place in physics analysis. Great care must be taken in their calculation and use especially in cases of limited statistics. We introduce the concept of statistical errors of confidence limits and argue that not only should limits be calculated but also their errors in order to represent the results of the analysis to the fullest. We show that comparison of two different limits from two different experiments becomes easier when their errors are also quoted. Use of errors of confidence limits will lead to abatement of the debate on which method is best suited to calculate confidence limits.
Date: March 22, 2002
Creator: Raja, Rajendran
Object Type: Article
System: The UNT Digital Library
How to Patch Active Plasma and Collisionless Sheath: Practical Guide (open access)

How to Patch Active Plasma and Collisionless Sheath: Practical Guide

Most plasmas have a very thin sheath compared with the plasma dimension. This necessitates separate calculations of the plasma and sheath. The Bohm criterion provides the boundary condition for calculation of plasma profiles. To calculate sheath properties, a value of electric field at the plasma-sheath interface has to be specified in addition to the Bohm criterion. The value of the boundary electric field and robust procedure to approximately patch plasma and collisionless sheath with a very good accuracy are reported.
Date: August 22, 2002
Creator: Kaganovich, Igor D.
Object Type: Report
System: The UNT Digital Library
Uranium Co-Precipitation with Iron Oxide Minerals (open access)

Uranium Co-Precipitation with Iron Oxide Minerals

In oxidizing environments, the toxic and radioactive element uranium is most soluble and mobile in the hexavalent oxidation state. These processes also affect the biological availability of U(VI) species toward reduction and precipitation as the less soluble U(IV) species by metal-reducing bacteria. The results provide compelling evidence of U incorporation within the hematite structure.
Date: May 22, 2002
Creator: Duff, M.C.
Object Type: Article
System: The UNT Digital Library
Supporting collaborative computing and interaction (open access)

Supporting collaborative computing and interaction

To enable collaboration on the daily tasks involved in scientific research, collaborative frameworks should provide lightweight and ubiquitous components that support a wide variety of interaction modes. We envision a collaborative environment as one that provides a persistent space within which participants can locate each other, exchange synchronous and asynchronous messages, share documents and applications, share workflow, and hold videoconferences. We are developing the Pervasive Collaborative Computing Environment (PCCE) as such an environment. The PCCE will provide integrated tools to support shared computing and task control and monitoring. This paper describes the PCCE and the rationale for its design.
Date: May 22, 2002
Creator: Agarwal, Deborah; McParland, Charles & Perry, Marcia
Object Type: Article
System: The UNT Digital Library
Mathematical comparison of three tritium system effluent HTO cleanup systems (open access)

Mathematical comparison of three tritium system effluent HTO cleanup systems

It is important that air emissions from tritium systems be kept as low as reasonably achievable. Thus, over the years a number of gas detritiation systems have been developed. Recently there has been interest in lower-cost, simpler systems which do not convert HT to the much more hazardous HTO form. Examples of such systems are (1) a bubbler/dehumidifier, (2) a bubbler/collector, and (3) an adsorber/collector. A computer model of each configuration was written and run. Each system's performance, including tritium buildup in liquid water, and tritium exhausted to the environment, are presented and compared.
Date: March 22, 2002
Creator: Willms, R.Scott; Gentile, Charles; Rule, Keith; Than, Chit & Williams, Philip
Object Type: Article
System: The UNT Digital Library
Semi-Annual Technical Progress Report of Radioisotope Power System Materials Production and Technology Program Tasks for October 1, 2001 Through March 31, 2002 (open access)

Semi-Annual Technical Progress Report of Radioisotope Power System Materials Production and Technology Program Tasks for October 1, 2001 Through March 31, 2002

The Office of Space and Defense Power Systems of the Department of Energy (DOE) provides Radioisotope Power Systems (RPS) for applications where conventional power systems are not feasible. For example, radioisotope thermoelectric generators were supplied by the DOE to the National Aeronautics and Space Administration for deep space missions including the Cassini Mission launched in October of 1997 to study the planet Saturn. The Oak Ridge National Laboratory (ORNL) has been involved in developing materials and technology and producing components for the DOE for more than three decades. For the Cassini Mission, for example, ORNL was involved in the production of carbon-bonded carbon fiber (CBCF) insulator sets, iridium alloy blanks and foil, and clad vent sets (CVS). This report has been divided into three sections to reflect program guidance from the Office of Space and Defense Power Systems for fiscal year (FY) 2002. The first section deals primarily with maintenance of the capability to produce flight quality (FQ) CBCF insulator sets, iridium alloy blanks and foil, and CVS. In all three cases, production maintenance is assured by the manufacture of limited quantities of FQ components. The second section deals with several technology activities to improve the manufacturing processes, characterize materials, …
Date: May 22, 2002
Creator: J. P. Moore, JPM
Object Type: Report
System: The UNT Digital Library
Storing, Retrieving, and Processing Optical Information by Raman Backscattering in Plasmas (open access)

Storing, Retrieving, and Processing Optical Information by Raman Backscattering in Plasmas

By employing stimulated Raman backscattering in a plasma, information carried by a laser pulse can be captured in the form of a very slowly propagating plasma wave that persists for a time large compared with the pulse duration. If the plasma is then probed with a short laser pulse, the information stored in the plasma wave can be retrieved in a second scattered electromagnetic wave. The recording and retrieving processes can conserve robustly the pulse shape, thus enabling the recording and retrieving with fidelity of information stored in optical signals.
Date: January 22, 2002
Creator: Fisch, I.Y. Dodin and N.J.
Object Type: Report
System: The UNT Digital Library
Increased Oil Recovery from Mature Oil Fields Using Gelled Polymer Treatments, Annual Report, June 16,2000-June 15, 2001 (open access)

Increased Oil Recovery from Mature Oil Fields Using Gelled Polymer Treatments, Annual Report, June 16,2000-June 15, 2001

This program was aimed at reducing barriers to the widespread use of gelled polymer treatments by (1) developing methods to predict gel behavior during placement in matrix rock and fractures, (2) determining the persistence of permeability reduction after gel placement, and (3) developing methods to design production well treatments to control water production.
Date: May 22, 2002
Creator: Willhite, G.P.; Green, D.W. & McCool, C.S.
Object Type: Report
System: The UNT Digital Library
Oxidation Behavior of Mo-Si-B Alloys in Wet Air (open access)

Oxidation Behavior of Mo-Si-B Alloys in Wet Air

Multiphase composite alloys based on the Mo-Si-B system are candidate materials for ultra-high temperature applications. In non load-bearing uses such as thermal barrier coatings or heat exchangers in fossil fuel burners, these materials may be ideally suited. The present work investigated the effect of water vapor on the oxidation behavior of Mo-Si-B phase assemblages. Three alloys were studied: Alloy 1 = Mo{sub 5}Si{sub 3}B{sub x} (T1)- MoSi{sub 2}- MoB, Alloy 2 = T1- Mo{sub 5}SiB{sub 2} (T2)- Mo{sub 3}Si, and Alloy 3 = Mo- T2- Mo{sub 3}Si. Tests were conducted at 1000 and 1100C in controlled atmospheres of dry air and wet air nominally containing 18, 55, and 150 Torr H{sub 2}O. The initial mass loss of each alloy was approximately independent of the test temperature and moisture content of the atmosphere. The magnitude of these initial losses varied according to the Mo content of the alloys. All alloys formed a continuous, external silica scale that protected against further mass change after volatilization of the initially formed MoO{sub 3}. All alloys experienced a small steady state mass change, but the calculated rates cannot be quantitatively compared due to statistical uncertainty in the individual mass measurements. Of particular interest is that …
Date: April 22, 2002
Creator: Kramer, M.; Thom, A.; Degirmen, O.; Behrani, V. & Akinc, M.
Object Type: Report
System: The UNT Digital Library
High-temperature corrosion in power-generating systems. (open access)

High-temperature corrosion in power-generating systems.

Several technologies are being developed to convert coal into clean fuel for use in power generation. From the standpoint of component materials in these technologies, the environments created by coal conversion and their interactions with materials are of interest. Coal is a complex and relatively dirty fuel that contains varying amounts of sulfur and a substantial fraction of noncombustible mineral constituents, commonly called ash. Corrosion of metallic and ceramic structural materials is a potential problem at elevated temperatures in the presence of complex gas environments and coal-derived solid/liquid deposits. This paper discusses the coal-fired systems currently under development, identifies several modes of corrosion degradation that occur in many of these systems, and suggests possible mechanisms of metal wastage. Available data on the performance of materials in some of the environments are highlighted, and the research needed to improve the corrosion resistance of various materials is presented.
Date: May 22, 2002
Creator: Natesan, K.
Object Type: Article
System: The UNT Digital Library
Maximizing Return From Sound Analysis and Design Practices (open access)

Maximizing Return From Sound Analysis and Design Practices

With today's tightening budgets computer applications must provide ''true'' long-term benefit to the company. Businesses are spending large portions of their budgets ''Re-Engineering'' old systems to take advantage of ''new'' technology. But what they are really getting is simply a new interface implementing the same incomplete or poor defined requirements as before. ''True'' benefit can only be gained if sound analysis and design practices are used. WHAT data and processes are required of a system is not the same as HOW the system will be implemented within a company. It is the System Analyst's responsibility to understand the difference between these two concepts. The paper discusses some simple techniques to be used during the Analysis and Design phases of projects, as well as the information gathered and recorded in each phase and how it is transformed between these phases. The paper also covers production application generated using Oracle Designer. Applying these techniques to ''real world'' problems, the applications will meet the needs for today's business and adapt easily to ever-changing business environments.
Date: April 22, 2002
Creator: Bramlette, J.D.
Object Type: Article
System: The UNT Digital Library
3Q/4Q 2001 Annual M-Area and Metallurgical Laboratory Hazardous Waste Management Facilities Groundwater Monitoring and Corrective-Action Report - Annual 2001 - Volumes I and II (open access)

3Q/4Q 2001 Annual M-Area and Metallurgical Laboratory Hazardous Waste Management Facilities Groundwater Monitoring and Corrective-Action Report - Annual 2001 - Volumes I and II

This report describes the groundwater monitoring and corrective-action program at the M-Area Hazardous Waste Management Facility (HWMF) and the Metallurgical Laboratory (Met Lab) HWMF at the Savannah River Site (SRS) during the third and fourth quarters of 2001. The report also provides a summary of the corrective-action program for the entire year. This program is required by South Carolina Resource Conservation and Recovery Act (RCRA) Hazardous Waste Permit SC1 890 008 989 and Section 264.100(g) of the South Carolina Hazardous Waste Management Regulations.
Date: April 22, 2002
Creator: Blas, J. F.
Object Type: Report
System: The UNT Digital Library
Cryogenics in Bepcii Upgrade. (open access)

Cryogenics in Bepcii Upgrade.

THIS PAPER PRESENTS A CRYOGENIC DESIGN FOR UPGRADING THE BEIJING ELECTRON POSITRON COLLIDER AT THE INSTITUTE OF HIGH ENERGY PHYSICS IN BEIJING. THE UPGRADE INVOLVES 3 NEW SUPERCONDUCTING FACILITIES, THE INTERACTION REGION QUADRUPOLE MAGNETS, THE DETECTOR SOLENOID MAGNETS AND THE SRF CAVITIES. FOR COOLING OF THESE DEVICES, A NEW CRYPLANT WITH A TOTAL CAPACITY OF 1.0KW AT 4.5K IS TO BE BUILT AT IHEP. AN INTEGRATED CRYOGENIC DESIGN TO FIT THE BEPCII CRYOGENIC LOADS WITH HIGH EFFICIENCY IS CARRIEDOUT USING COMPUTATIONAL PROCESS ANALYSIS SOFTWARE WITH THE EMPHASES ON ECONOMICS AND SAFETY IN BOTH CONSTRUCTION AND OPERATION OF THE PLANT. THIS PAPER DESCRIBES THE CRYOGENIC CHARACTERISTICS OF EACH SUPERCONDUCTING DEVICE, THEIR COOLING SCHEMES AND THE OVERALL CRYOPLANT.
Date: July 22, 2002
Creator: Jia, L.; Wang, L. & Li, S.
Object Type: Article
System: The UNT Digital Library
2003 International High-Level Radioactive Waste Management Conference Breached Drip Shield Test and Validation of a TSPA Sub-Model (open access)

2003 International High-Level Radioactive Waste Management Conference Breached Drip Shield Test and Validation of a TSPA Sub-Model

The Engineered Barrier System (EBS) represents the system of human engineered barriers in the isolation of high-level radioactive waste in the proposed repository at Yucca Mountain. It is designed to complement and enhance the natural barriers to isolate and prevent the transport of radionuclides into the surrounding environment. The transport mechanism most frequently postulated for radionuclides is liquid water flux that has penetrated the EBS through corrosion breaches in the drip shield and waste packages (WP). A water flux-splitting model is used to predict flow through WP and drip shield breaches and is documented in the ''EBS Radionuclide Transport Abstraction''. A future revision of the ''EBS Radionuclide Transport Abstraction'' will be one component of the total system performance assessment--license application (TSPA-LA) for the Yucca Mountain repository. The flux-splitting model is conservative based on the following assumptions: (1) Drip impact occurs without a loss of water mass. (2) Dripping flux falls exactly at the crown of the drip shield as opposed to different locations on the curved surface, which will effect splashing and flow patterns. (3) The flux passing through a drip shield patch is proportional to the ratio of the length of the penetration in the axial direction to the …
Date: November 22, 2002
Creator: Walton, Z.P. & Kam, J.T.
Object Type: Report
System: The UNT Digital Library
INTERNATIONAL ENGLISH MANUAL (open access)

INTERNATIONAL ENGLISH MANUAL

This document presents a set of guidelines for authors who wish to express themselves more clearly to foreign readers, or readers whose first language is not American English. Topics include idioms, technical terms, jargon, word meaning, acronyms, and international conventions of measurement. The guidelines will help writers of technical documents present their ideas more effectively to audiences that may include individuals whose first language is not American English, including audiences with individuals from other English-speaking countries.
Date: February 22, 2002
Creator: AMADOR, MABLE & KELLER, YVONNE KELLER
Object Type: Report
System: The UNT Digital Library
Report of the First Community Consultation on the Responsible Collection and Use of Samples for Genetic Research, September 25-26, 2000 (open access)

Report of the First Community Consultation on the Responsible Collection and Use of Samples for Genetic Research, September 25-26, 2000

The First Community Consultation on the Responsible Collection and Use of Samples for Genetic Research was held in Bethesda, Maryland, on September 25-26, 2000. The consultation was convened by the National Institute of General Medical Sciences (NIGMS) of the National Institutes of Health (NIH). Approximately 120 individuals participated in the consultation, half from a broad range of communities and populations, and half from government. The participants shared their views and concerns about population- and community-based genetic research, expanding the focus of the meeting from the collection and use of blood or other tissue samples for genetic research to broader issues and concerns about the conduct of genetic research in general with populations and communities.
Date: May 22, 2002
Creator: Greenberg, Judith H.
Object Type: Article
System: The UNT Digital Library
A three-dimensional numerical model of predevelopment conditions in the Death Valley regional ground-water flow system, Nevada and California (open access)

A three-dimensional numerical model of predevelopment conditions in the Death Valley regional ground-water flow system, Nevada and California

In the early 1990's, two numerical models of the Death Valley regional ground-water flow system were developed by the U.S. Department of Energy. In general, the two models were based on the same basic hydrogeologic data set. In 1998, the U.S. Department of Energy requested that the U.S. Geological Survey develop and maintain a ground-water flow model of the Death Valley region in support of U.S. Department of Energy programs at the Nevada Test Site. The purpose of developing this ''second-generation'' regional model was to enhance the knowledge and understanding of the ground-water flow system as new information and tools are developed. The U.S. Geological Survey also was encouraged by the U.S. Department of Energy to cooperate to the fullest extent with other Federal, State, and local entities in the region to take advantage of the benefits of their knowledge and expertise. The short-term objective of the Death Valley regional ground-water flow system project was to develop a steady-stat e representation of the predevelopment conditions of the ground-water flow system utilizing the two geologic interpretations used to develop the previous numerical models. The long-term objective of this project was to construct and calibrate a transient model that simulates the ground-water …
Date: November 22, 2002
Creator: D'Agnese, F. A.; O'Brien, G. M.; Faunt, C. C.; Belcher, W. R. & San Juan, Carma
Object Type: Report
System: The UNT Digital Library
Mixing of CO2 and CH4 in gas reservoirs: Code comparison studies (open access)

Mixing of CO2 and CH4 in gas reservoirs: Code comparison studies

Simulation of the mixing of carbon dioxide and methane is critical to modeling gas reservoir processes induced by the injection of carbon dioxide. We have compared physical property estimates and simulation results of the mixing of carbon dioxide and methane gases from four numerical simulation codes. Test Problem 1 considers molecular diffusion in a one-dimensional stably stratified system. Test Problem 2 considers molecular diffusion and advection in an unstable two-dimensional system. In general, fair to good agreement was observed between the codes tested.
Date: July 22, 2002
Creator: Oldenburg, Curt; Law, D.H.-S.; Le Gallo, Y. & White, S.P.
Object Type: Article
System: The UNT Digital Library
Cylindrical Wire Electrical Discharge Machining of Metal Bond Diamond Wheels- Part II: Wheel Wear Mechanism (open access)

Cylindrical Wire Electrical Discharge Machining of Metal Bond Diamond Wheels- Part II: Wheel Wear Mechanism

The use of stereo scanning Electron Microscopy (SEM) to investigate the wear mechanism of the wire EDM true metal bond diamond wheel for ceramic grinding is presented. On the grinding wheel, a wedge-shape removal part was machined to enable the examination and measurement of the worn wheel surfaces using the stereo SEM. The stereo SEM was calibrated by comparing results of depth profile of a wear groove with the profilometer measurements. On the surface of the grinding wheel after wire EDM truing and before grinding, the diamond protruding heights were measured in the level of 35 {micro}m, comparing to the 54 {micro}m average size of the diamond in the grinding wheel. The gap between the EDM wire and rotating grinding wheel is estimated to be about 35 to 40 {micro}m. This observation indicates that, during the wire EDM, electrical sparks occur between the metal bond and EDM wire, which leaves the diamond protruding in the gap between the wire and wheel. The protruding diamond is immediately fractured at the start of the grinding process, even under a light grinding condition. After heavy grinding, the grinding wheel surface and the diamond protrusion heights are also investigated using the stereo SEM. The …
Date: January 22, 2002
Creator: McSpadden, SB
Object Type: Report
System: The UNT Digital Library
Removal of Uranium from Plutonium Solutions by Anion Exchange (open access)

Removal of Uranium from Plutonium Solutions by Anion Exchange

The anion exchange capacity in the HB-Line Phase II Facility will be used to purify plutonium solutions potentially containing significant quantities of depleted uranium. Following purification, the plutonium will be precipitated as an oxalate and calcined to plutonium oxide (PuO2) for storage until final disposition.
Date: March 22, 2002
Creator: Rudisill, T.S.
Object Type: Report
System: The UNT Digital Library
Well-to-wheels analysis of fuel-cell vehicle/fuel systems. (open access)

Well-to-wheels analysis of fuel-cell vehicle/fuel systems.

Major automobile companies worldwide are undertaking vigorous research and development efforts aimed at developing fuel-cell vehicles (FCVs). Proton membrane exchange (PEM)-based FCVs require hydrogen (H{sub 2}) as the fuel-cell (FC) fuel. Because production and distribution infrastructure for H{sub 2} off board FCVs as a transportation fuel does not exist yet, researchers are developing FCVs that can use hydrocarbon fuels, such as methanol (MeOH) and gasoline, for onboard production of H{sub 2} via fuel processors. Direct H{sub 2} FCVs have no vehicular emissions, while FCVs powered by hydrocarbon fuels have near-zero emissions of criteria pollutants and some carbon dioxide (CO{sub 2}) emissions. However, production of H{sub 2} can generate a large amount of emissions and suffer significant energy losses. A complete evaluation of the energy and emission impacts of FCVs requires an analysis of energy use and emissions during all stages, from energy feedstock wells to vehicle wheels--a so-called ''well-to-wheels'' (WTW) analysis. This paper focuses on FCVs powered by several transportation fuels. Gasoline vehicles (GVs) equipped with internal combustion engines (ICEs) are the baseline technology to which FCVs are compared. Table 1 lists the 13 fuel pathways included in this study. Petroleum-to-gasoline (with 30-ppm sulfur [S] content) is the baseline fuel …
Date: January 22, 2002
Creator: Wang, M.
Object Type: Article
System: The UNT Digital Library
235U Holdup Measurements in the 321-M Exhaust Elbows (open access)

235U Holdup Measurements in the 321-M Exhaust Elbows

The Analytical Development Section of Savannah River Technology Center (SRTC) was requested by the Facilities Disposition Division (FDD) to determine the holdup of enriched uranium in the 321-M facility as part of an overall deactivation project of the facility. The 321-M facility was used to fabricate enriched uranium fuel assemblies, lithium-aluminum target tubes, neptunium assemblies, and miscellaneous components for the production reactors. The facility also includes the 324-M storage building and the passageway connecting it to 321-M. The results of the holdup assays are essential for determining compliance with the Waste Acceptance Criteria, Material Control and Accountability, and to meet criticality safety controls. This report covers holdup measurements of uranium residue in the exhaust piping elbows removed from the roof the 321-M facility.
Date: March 22, 2002
Creator: Salaymeh, S.R.
Object Type: Report
System: The UNT Digital Library
High Purity Germanium Gamma-PHA Assay of Uranium in Scrap Cans for 321-M Facility (open access)

High Purity Germanium Gamma-PHA Assay of Uranium in Scrap Cans for 321-M Facility

The Analytical Development Section of SRTC was requested by the Facilities Disposition Division to determine the holdup of enriched uranium in the 321-M facility as part of an overall deactivation project of the facility. This report includes a description of two efficiency calibration configurations and also the results of the assay. A description of the quality control checks is included as well.
Date: March 22, 2002
Creator: Salaymeh, S.R.
Object Type: Report
System: The UNT Digital Library