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A 1 MEGAWATT POLYPHASE BOOST CONVERTER-MODULATOR FOR KLYSTRON PULSE APPLICATION
This paper describes electrical design criteria and first operational results a 140 kV, 1 MW average, 11 MW peak, zero-voltage-switching 20 kHz polyphase bridge, boost converter/modulator for klystron pulse application. The DC-DC converter derives the buss voltages from a standard 13.8 kV to 2300 Y substation cast-core transformer. Energy storage and filtering is provided by self-clearing metallized hazy polypropylene traction capacitors. Three ''H-Bridge'' Insulated Gate Bipolar Transistor (IGBT) switching networks are used to generate the polyphase 20 kHz transformer primary drive waveforms. The 20 kHz drive waveforms are chirped the appropriate duration to generate the desired klystron pulse width. PWM (pulse width modulation) of the individual 20 kHz pulses is utilized to provide regulated output waveforms with adaptive feedforward and feedback techniques. The boost transformer design utilizes amorphous nanocrystalline material that provides the required low core loss at design flux levels and switching frequencies. Resonant shunt-peaking is used on the transformer secondary to boost output voltage and resonate transformer leakage inductance. With the appropriate transformer leakage inductance and peaking capacitance, zero-voltage-switching of the IGBT's is attained, minimizing switching losses. A review of these design parameters and the first results of the performance characteristics will be presented.
Date:
June 1, 2001
Creator:
Reass, W. A.; Doss, J. D. & Gribble, R. F.
Object Type:
Article
System:
The UNT Digital Library
N-15 SIGNALS OF NITROGEN SOURCE AND FATE IN A SEMI-ARID WETLANDS
None
Date:
August 1, 2001
Creator:
Heikoop, J. M. & Hickmott, D. D.
Object Type:
Article
System:
The UNT Digital Library
A 75-keV, 145-mA PROTON INJECTOR
None
Date:
July 1, 2001
Creator:
Sherman, J. D.; Figueroa, T. L. & Al, Et
Object Type:
Article
System:
The UNT Digital Library
1999 Annual Site Environmental Report, Sandia National Laboratories, Albuquerque, New Mexico
None
Date:
February 1, 2001
Creator:
Duncan, Dianne K.; Sanchez, Rebecca D. & Fink, Charles H.
Object Type:
Report
System:
The UNT Digital Library
2000 Transportation Baseline Report (DOE/ID-10754), 2000 Transporation Challenges,
The 2000 U. S. Department of Energy (DOE) Environmental Management (EM) Waste and Materials Disposition “Transportation Challenges” report is provided as an update to or status report on the transportation “barriers” analysis conducted in October 1999 and published in November 1999 as the National Transportation Program (NTP) Transportation Challenges “Problems Tied to Disposition Pathways.” Much of the programmatic information concerning the “barriers” or, more accurately, “issues,” has not changed since the first publication; however, efforts to resolve the issues have progressed to varying degrees over the last year. This report provides a current status of efforts to eliminate or mitigate the issues, and includes new issues identified since the original analyses were conducted. Resolving these issues will increase the probability of successful waste and materials disposition and decrease the likelihood of delays due to inadequate transportation resources or infrastructure. The issues addressed in this report generally affect more than one site and more than one waste or material stream.
Date:
February 1, 2001
Creator:
Fawcett, Ricky Lee; Kramer, George Leroy Jr.; Fawcett, Ricky Lee; Moss, Ralph John; Fawcett, Ricky Lee & John, Mark Earl
Object Type:
Report
System:
The UNT Digital Library
2001 Joint ADVISOR/PSAT Vehicle Systems Modeling User's Conference Proceedings (CD)
The 2001 Joint ADVISOR/PSAT Vehicle Systems Modeling User Conference provided an opportunity for engineers in the automotive industry and the research environment to share their experiences in vehicle systems modeling using ADVISOR and PSAT. ADVISOR and PSAT are vehicle systems modeling tools developed and supported by the National Renewable Energy Laboratory and Argonne National Laboratory respectively with the financial support of the US Department of Energy. During this conference peers presented the results of studies using the simulation tools and improvements that they have made or would like to see in the simulation tools. Focus areas of the presentations included Control Strategy, Model Validation, Optimization and Co-Simulation, Model Development, Applications, and Fuel Cell Vehicle Systems Analysis. Attendees were offered the opportunity to give feedback on future model development plans.
Date:
August 1, 2001
Creator:
Markel, T.
Object Type:
Article
System:
The UNT Digital Library
21st century energy solutions. Coal and Power Systems FY2001 program briefing
The continued strength of American's economy depends on the availability of affordable energy, which has long been provided by the Nations rich supplies of fossil fuels. Forecasts indicate that fossil fuels will continue to meet much of the demand for economical electricity and transportation fuels for decades to come. It is projected that natural gas, oil, and coal will supply nearly 90% of US energy in 2020, with coal fueling around 50% of the electricity. It is essential to develop ways to achieve the objectives for a cleaner environment while using these low-cost, high-value fuels. A national commitment to improved technologies--for use in the US and abroad--is the solution. The Coal and Power Systems program is responding to this commitment by offering energy solutions to advance the clean, efficient, and affordable use of the Nations abundant fossil fuel resources. These solutions include: (1) Vision 21--A multi-product, pollution-free energy plant--producing electricity, fuels, and/or industry heat--could extract 80% or more of the energy value of coal and 85% or more of the energy value of natural gas; (2) Central Power Systems--Breakthrough turbines and revolutionary new gasification technologies that burn less coal and gas to obtain energy, while reducing emissions; (3) Distributed Generation--Fuel …
Date:
January 1, 2001
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
The A dependence of open charm and bottom production
We study inclusive heavy quark and exclusive heavy quark pair production in pp, pA and AA interactions. Intrinsic transverse momentum is introduced in pp interactions. Nuclear effects, limited to k{sub T} broadening and nuclear shadowing, are introduced in pA and AA interactions. The nuclear dependence is studied over a range of energies, both in fixed target and collider setups.
Date:
January 1, 2001
Creator:
Vogt, R.
Object Type:
Article
System:
The UNT Digital Library
ABSOLUTE PARTIAL GAMMA-RAY CROSS SECTIONS IN 238U(n,xngamma) REACTIONS
None
Date:
July 1, 2001
Creator:
Fotiadis, N.; Johns, G. & Al, Et
Object Type:
Article
System:
The UNT Digital Library
Abstracts of Reports and Testimony: Fiscal Year 2000
A letter report issued by the General Accounting Office with an abstract that begins "The U.S. General Accounting Office (GAO) is an independent, nonpartisan agency in the legislative branch. GAO provides Congress with the best information available to help members make informed oversight, policy, and funding decisions. GAO meets Congress' information needs by (1) evaluating how government programs and policies are working, (2) auditing agency operations to determine whether federal funds are being spent efficiently and effectively, (3) investigating allegations of illegal and improper activities, and (4) issuing legal decisions and opinions. Most GAO work is done at the request of committees or members, but some reports are self-initiated or done in response to congressional mandates included in public laws or committee reports. GAO's annual index is a two-volume set. The first volume--Abstracts of Reports and Testimony: Fiscal Year 2000--contains summaries of 878 publicly released reports and testimony listed alphabetically by division or staff office. Classified reports, correspondence, and legal publications are not included. The second volume--Indexes for Reports and Testimony: Fiscal Year 2000--contains several indexes to help you locate reports and testimony by issue category, subject matter, title, or GAO witness. The annual index is also available in electronic …
Date:
March 1, 2001
Creator:
United States. General Accounting Office.
Object Type:
Report
System:
The UNT Digital Library
AC-Current Burn-Through of 13-mm-Thick Aluminum and Steel
None
Date:
September 1, 2001
Creator:
LOESCHER, DOUGLAS H.
Object Type:
Report
System:
The UNT Digital Library
ACCELERATED SITE TECHNOLOGY DEPLOYMENT COST AND PERFORMANCE REPORT COMPARABILITY OF ISOCS INSTRUMENT IN RADIONUCLIDE CHARACTERICATION AT BROOKHAVEN NATIONAL LABORATORY
This report describes a DOE Accelerated Site Technology Deployment project being conducted at Brookhaven National Laboratory to deploy innovative, radiological, in situ analytical techniques. The technologies are being deployed in support of efforts to characterize the Brookhaven Graphite Research Reactor (BGRR) facility, which is currently undergoing decontamination and decommissioning. This report focuses on the deployment of the Canberra Industries In Situ Object Counting System (ISOCS) and assesses its data comparability to baseline methods of sampling and laboratory analysis. The battery-operated, field deployable gamma spectrometer provides traditional spectra of counts as a function of gamma energy. The spectra are then converted to radionuclide concentration by applying innovative efficiency calculations using monte carlo statistical methods and pre-defined geometry templates in the analysis software. Measurement of gamma emitting radionuclides has been accomplished during characterization of several BGRR components including the Pile Fan Sump, Above Ground Ducts, contaminated cooling fans, and graphite pile internals. Cs-137 is the predominant gamma-emitting radionuclide identified, with smaller quantities of Co-60 and Am-241 detected. The Project used the Multi-Agency Radiation Survey and Site Investigation Manual guidance and the Data Quality Objectives process to provide direction for survey planning and data quality assessment. Analytical results have been used to calculate …
Date:
March 1, 2001
Creator:
KALB,P.; LUCKETT,L.; MILLER,K.; GOGOLAK,C. & MILIAN,L.
Object Type:
Report
System:
The UNT Digital Library
Accelerator Mass Spectrometry Measurements of Plutonium in Sediment and Seawater from the Marshall Islands
During the summer 2000, I was given the opportunity to work for about three months as a technical trainee at Lawrence Livermore National Laboratory, or LLNL as I will refer to it hereafter. University of California runs this Department of Energy laboratory, which is located 70 km east of San Francisco, in the small city of Livermore. This master thesis in Radioecology is based on the work I did here. LLNL, as a second U.S.-facility for development of nuclear weapons, was built in Livermore in the beginning of the 1950's (Los Alamos in New Mexico was the other one). It has since then also become a 'science center' for a number of areas like magnetic and laser fusion energy, non-nuclear energy, biomedicine, and environmental science. The Laboratory's mission has changed over the years to meet new national needs. The following two statements were found on the homepage of LLNL (http://www.llnl.gov), at 2001-03-05, where also information about the laboratory and the scientific projects that takes place there, can be found. 'Our primary mission is to ensure that the nation's nuclear weapons remain safe, secure, and reliable and to prevent the spread and use of nuclear weapons worldwide'. 'Our goal is to …
Date:
August 1, 2001
Creator:
Leisvik, M & Hamilton, T
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Accelerator Operators and Software Development
At Thomas Jefferson National Accelerator Facility, accelerator operators perform tasks in their areas of specialization in addition to their machine operations duties. One crucial area in which operators contribute is software development. Operators with programming skills are uniquely qualified to develop certain controls applications because of their expertise in the day-to-day operation of the accelerator. Jefferson Lab is one of the few laboratories that utilizes the skills and knowledge of operators to create software that enhances machine operations. Through the programs written; by operators, Jefferson Lab has improved machine efficiency and beam availability. Because many of these applications involve automation of procedures and need graphical user interfaces, the scripting language Tcl and the Tk toolkit have been adopted. In addition to automation, some operator-developed applications are used for information distribution. For this purpose, several standard web development tools such as perl, VBScript, and ASP are used. Examples of applications written by operators include injector steering, spin angle changes, system status reports, magnet cycling routines, and quantum efficiency measurements. This paper summarizes how the unique knowledge of accelerator operators has contributed to the success of the Jefferson Lab control system. *This work was supported by the U.S. DOE contract No. DE-AC05-84-ER40150.
Date:
November 1, 2001
Creator:
Miller, April & Joyce, Michele
Object Type:
Article
System:
The UNT Digital Library
Accounting Principles, Standards, and Requirements: Title 2 Standards Not Superceded by FASAB Issuances
Guidance issued by the General Accounting Office with an abstract that begins "This is one in a series or reports designed to help federal agencies improve or maintain effective internal control, financial management systems, and financial reporting. GAO discusses the status of the 13 remaining standards in Title 2, "Accounting," of the GAO Policy and Procedures Manual for Guidance of Federal Agencies in light of the most recent compendium of Federal Accounting Standards Advisory Board (FASAB) standards and guidance. GAO either (1) reprinted the standards that remain in effect, along with any updated citations to relevant guidance, or (2) provided the citation of current guidance replacing that standard."
Date:
November 1, 2001
Creator:
United States. General Accounting Office.
Object Type:
Text
System:
The UNT Digital Library
Accurate GPS Time-Linked Data Acquisition System (ATLAS) User's Manual
None
Date:
May 1, 2001
Creator:
BERG,DALE E. & ZAYAS,JOSE R.
Object Type:
Report
System:
The UNT Digital Library
Accurate hydrogen depth profiling by reflection elastic recoil detection analysis
A technique to convert reflection elastic recoil detection analysis spectra to depth profiles, the channel-depth conversion, was introduced by Verda, et al [1]. But the channel-depth conversion does not correct for energy spread, the unwanted broadening in the energy of the spectra, which can lead to errors in depth profiling. A work in progress introduces a technique that corrects for energy spread in elastic recoil detection analysis spectra, the energy spread correction [2]. Together, the energy spread correction and the channel-depth conversion comprise an accurate and convenient hydrogen depth profiling method.
Date:
January 1, 2001
Creator:
Verda, R. D. (Raymond D.); Tesmer, Joseph R.; Nastasi, Michael Anthony, & Bower, R. W. (Robert W.)
Object Type:
Article
System:
The UNT Digital Library
Accurate Hydrogen Depth Profiling by Reflection Elastic Recoil Detection Analysis
None
Date:
July 1, 2001
Creator:
Verda, R. D.; Tesmer, J. R. & Al, Et
Object Type:
Article
System:
The UNT Digital Library
ACME Algorithms for Contact in a Multiphysics Environment API Version 0.3a
An effort is underway at Sandia National Laboratories to develop a library of algorithms to search for potential interactions between surfaces represented by analytic and discretized topological entities. This effort is also developing algorithms to determine forces due to these interactions for transient dynamics applications. This document describes the Application Programming Interface (API) for the ACME (Algorithms for Contact in a Multiphysics Environment) library.
Date:
April 1, 2001
Creator:
BROWN, KEVIN H.; GLASS, MICHEAL W.; GULLERUD, ARNE S.; HEINSTEIN, MARTIN W.; JONES, REESE E. & SUMMERS, RANDALL M.
Object Type:
Report
System:
The UNT Digital Library
ACME - Algorithms for Contact in a Multiphysics Environment API Version 1.0
An effort is underway at Sandia National Laboratories to develop a library of algorithms to search for potential interactions between surfaces represented by analytic and discretized topological entities. This effort is also developing algorithms to determine forces due to these interactions for transient dynamics applications. This document describes the Application Programming Interface (API) for the ACME (Algorithms for Contact in a Multiphysics Environment) library.
Date:
October 1, 2001
Creator:
BROWN, KEVIN H.; SUMMERS, RANDALL M.; GLASS, MICHEAL W.; GULLERUD, ARNE S.; HEINSTEIN, MARTIN W. & JONES, REESE E.
Object Type:
Report
System:
The UNT Digital Library
Acoustic Monitor for Liquid Solid Slurries Measurements at Low Weight Fractions
The principal objective of the project is to develop an acoustic probe for determining the volume fraction of particles in a flowing suspension. This will include testing the theory of acoustic wave propagation in suspensions and demonstrating the application of the probe by installing it on a flow loop through which a suspension is flowing and determining the particle volume fraction. The signal from the probe must be processed such that the noise arising from the presence of the gas bubbles, if present in the system, is removed to yield an accurate estimate of the particle volume fraction. Once the probe is developed and tested successfully at Syracuse University, it is to be installed and tested in the flow loop at Oak Ridge National Laboratories for surrogate slurries for the Hanford Nuclear site. Particular attention is to be given to testing suspensions with low particle volume fractions since slurries to be transported in nuclear waste processing will have low particle volume fractions.
Date:
June 1, 2001
Creator:
Taularides, L. L. & Sangani, A.
Object Type:
Report
System:
The UNT Digital Library
Acoustical Imaging and Mechanical Properties of Soft Rock and Marine Sediments Progress Report: April-June 2001
Mechanically weak formations, such as chalks, high porosity sandstones, and marine sediments, pose significant problems for oil and gas operators. Problems such as compaction, subsidence, and loss of permeability can affect reservoir production operations. For example, the unexpected subsidence of the Ekofisk chalk in the North Sea required over one billion dollars to re-engineer production facilities to account for losses created during that compaction (Sulak 1991). Another problem in weak formations is that of shallow water flows (SWF). Deep water drilling operations sometimes encounter cases where the marine sediments, at shallow depths just below the seafloor, begin to uncontrollably flow up and around the drill pipe. SWF problems created a loss of $150 million for the Ursa development project in the U.S. Gulf Coast SWF (Furlow 1998a,b; 1999a,b). The goal of this project is to provide a database on both the rock mechanical properties and the geophysical properties of weak rocks and sediments. These could be used by oil and gas companies to detect, evaluate, and alleviate potential production and drilling problems. The results will be useful in, for example, pre-drill detection of events such as SWF's by allowing a correlation of seismic data (such as hazard surveys) to rock …
Date:
July 1, 2001
Creator:
Scott, Thurman E., Jr.; Abousleiman, Younane & Zaman, Musharraf
Object Type:
Report
System:
The UNT Digital Library
Acoustical Imaging and Mechanical Properties of Soft Rock and Marine Sediments Progress Report: January-March 2001
The oil and gas industry has encountered significant problems in the production of oil and gas from weak rocks (such as chalks and limestones) and from unconsolidated sand formations. Problems include subsidence, compaction, sand production, and catastrophic shallow water sand flows during deep water drilling. Together these cost the petroleum industry hundreds of millions of dollars annually. The goals of this first quarterly report is to document the progress on the project to provide data on the acoustic imaging and mechanical properties of soft rock and marine sediments. The project is intended to determine the geophysical (acoustic velocities) rock properties of weak, poorly cemented rocks and unconsolidated sands. In some cases these weak formations can create problems for reservoir engineers. For example, it cost Phillips Petroleum 1 billion dollars to repair of offshore production facilities damaged during the unexpected subsidence and compaction of the Ekofisk Field in the North Sea (Sulak 1991). Another example is the problem of shallow water flows (SWF) occurring in sands just below the seafloor encountered during deep water drilling operations. In these cases the unconsolidated sands uncontrollably flow up around the annulus of the borehole resulting in loss of the drill casing. The $150 million …
Date:
April 1, 2001
Creator:
Scott, Thurman E., Jr.; Zaman, Musharraf & Abousleiman, Younane
Object Type:
Report
System:
The UNT Digital Library
Acquisition and processing of multiparametric information from apixelmatrix
This paper addresses the design of a system intended to readout multiparametric information from a matrix of pixels. The system presented here acquires the charge associated with the signal and provides a timing information from each pixel. Although it lends itself to a broad range of time-correlated imaging situations involving any kind of pixel matrices, the design constraints assumed here are particularly tailored to the application with pixels that sense the output charge distribution from a Micro Channel Plate (MCP). The combination of a microchannel plate and a pixel matrix is an extremely versatile detector and the readout system must be able to fully exploit the intrinsically high position resolution and time accuracy featured by the MCP. The behavior of the readout system described in this paper is based upon advanced concepts to meet the above application requirements and is believed to provide a significant functional improvement over the conventional pixel systems.
Date:
February 1, 2001
Creator:
Manfredi, P.F.; Millaud, J.E. & Sushkov, V.V.
Object Type:
Article
System:
The UNT Digital Library