High Power Long Pulse Performance of the Diii-D Gyrotron Installation (open access)

High Power Long Pulse Performance of the Diii-D Gyrotron Installation

At DIII-D, five 110 GHz gyrotrons are operating routinely for 2.0 s pulses at generated power levels {ge}750 kW per gyrotron. A sixth gyrotron is being installed, which should bring the generated power level to >4 MW and the injected power to about 3.0 MW. The output power now can be modulated by the plasma control system to fix T{sub e} at a desired value. The system is being used as a tool for control of current diffusion, for current profile control and other experiments leading to advanced tokamak operation.
Date: May 1, 2002
Creator: Lohr, J.; Gorelov, Y. A.; Callis, R. W.; Grunloh, H. J.; Peavy, J. J.; Pinsker, R. I. et al.
Object Type: Article
System: The UNT Digital Library
Exposure chamber measurements of mass transfer and partitioning at the plant/air interface (open access)

Exposure chamber measurements of mass transfer and partitioning at the plant/air interface

None
Date: May 1, 2002
Creator: Maddalena, Randy L.; McKone, Thomas E. & Kado, Norman Y.
Object Type: Article
System: The UNT Digital Library
Refines Efficiency Improvement (open access)

Refines Efficiency Improvement

Refinery processes that convert heavy oils to lighter distillate fuels require heating for distillation, hydrogen addition or carbon rejection (coking). Efficiency is limited by the formation of insoluble carbon-rich coke deposits. Heat exchangers and other refinery units must be shut down for mechanical coke removal, resulting in a significant loss of output and revenue. When a residuum is heated above the temperature at which pyrolysis occurs (340 C, 650 F), there is typically an induction period before coke formation begins (Magaril and Aksenova 1968, Wiehe 1993). To avoid fouling, refiners often stop heating a residuum before coke formation begins, using arbitrary criteria. In many cases, this heating is stopped sooner than need be, resulting in less than maximum product yield. Western Research Institute (WRI) has developed innovative Coking Index concepts (patent pending) which can be used for process control by refiners to heat residua to the threshold, but not beyond the point at which coke formation begins when petroleum residua materials are heated at pyrolysis temperatures (Schabron et al. 2001). The development of this universal predictor solves a long standing problem in petroleum refining. These Coking Indexes have great potential value in improving the efficiency of distillation processes. The Coking …
Date: May 15, 2002
Creator: WRI
Object Type: Report
System: The UNT Digital Library
RAD/COMM ''Cricket'' Test Report (open access)

RAD/COMM ''Cricket'' Test Report

A series of tests were performed at Oak Ridge National Laboratory (ORNL) to evaluate and characterize the radiological response of a ''Cricket'' radiation detection system. The ''Cricket'' is manufactured by RAD/COMM Systems Corp., which is located in Ontario, Canada. The system is designed to detect radioactive material that may be contained in scrap metal. The Cricket's detection unit is mounted to the base of a grappler and monitors material, while the grappler's tines hold the material. It can also be used to scan material in an attempt to isolate radioactive material if an alarm occurs. Testing was performed at the Environmental Effects Laboratory located at ORNL and operated by the Engineering Science and Technology Division. Tests performed included the following: (1) Background stability, (2) Energy response using {sup 241}Am, {sup 137}Cs, and {sup 60}Co, (3) Surface uniformity, (4) Angular dependence, (5) Alarm actuation, (6) Alarm threshold vs. background, (7) Shielding, (8) Response to {sup 235}U, (9) Response to neutrons using unmoderated {sup 252}Cf, and (10) Response to transient radiation. This report presents a summary of the test results. Background measurements were obtained prior to the performance of each individual test.
Date: May 20, 2002
Creator: Chiaro, P. J.
Object Type: Report
System: The UNT Digital Library
Atomic Physics Processes Important to the Understanding of the Scrape-Off Layer of Tokamaks (open access)

Atomic Physics Processes Important to the Understanding of the Scrape-Off Layer of Tokamaks

The region between the well-confined plasma and the vessel walls of a magnetic confinement fusion research device, the scrape-off layer (SOL), is typically rich in atomic and molecular physics processes. The most advanced magnetic confinement device, the magnetically diverted tokamak, uses a magnetic separatrix to isolate the confinement zone (closed flux surfaces) from the edge plasma (open field lines). Over most of their length the open field lines run parallel to the separatrix, forming a thin magnetic barrier with the nearby vessel walls. In a poloidally-localized region, the open field lines are directed away from the separatrix and into the divertor, a region spatially separated from the separatrix where intense plasma wall interaction can occur relatively safely. Recent data from several tokamaks indicate that particle transport across the field lines of the SOL can be somewhat faster than previously thought. In these cases, the rate at which particles reach the vessel wall is comparable to the rate to the divertor from parallel transport. The SOL can be thin enough that the recycling neutrals and sputtered impurities from the wall may refuel or contaminate the confinement zone more efficiently than divertor plasma wall interaction. Just inside the SOL is a confinement …
Date: May 1, 2002
Creator: West, W. P.; Goldsmith, B.; Evans, T. E. & Olson, R. J.
Object Type: Article
System: The UNT Digital Library
Grain Growth Behavior, Tensile Impact Ductility, and Weldability of Cerium-Doped Iridium Alloys (open access)

Grain Growth Behavior, Tensile Impact Ductility, and Weldability of Cerium-Doped Iridium Alloys

An iridium alloy doped with small amounts of cerium and thorium is being developed as a potential replacement for the iridium-based DOP-26 alloy (doped with thorium only) that is currently used by the National Aeronautics and Space Administration (NASA) for cladding and post-impact containment of the radioactive fuel in radioisotope thermoelectric generator (RTG) heat sources which provide electric power for interplanetary spacecraft. This report summarizes results of studies conducted to date under the Iridium Alloy Characterization and Development subtask of the Radioisotope Power System Materials Production and Technology Program to characterize the properties of the iridium-based alloy (designated as DOP-40) containing both cerium and thorium. Included within this report are data on grain growth of sheet material in vacuum and low-pressure oxygen environments, grain growth in vacuum of the clad vent set cup material, weldability, and the effect of grain size and test temperature on tensile properties. Where applicable, data for the DOP-26 alloy are included for comparison. Both grain size and grain-boundary cohesion affect the ductility of iridium alloys. In this study it was found that cerium and thorium, when added together, refine grain size more effectively than when thorium is added by itself (especially at high temperatures). In …
Date: May 28, 2002
Creator: McKamey, C.G.
Object Type: Report
System: The UNT Digital Library
Exposure to motor vehicle emissions: An intake fraction approach (open access)

Exposure to motor vehicle emissions: An intake fraction approach

Motor vehicles are a significant source of population exposure to air pollution. Focusing on California's South Coast Air Basin as a case study, the author combines ambient monitoring station data with hourly time-activity patterns to determine the population intake of motor vehicle emissions during 1996-1999. Three microenvironments are considered wherein the exposure to motor vehicle emissions is higher than in ambient air: in and near vehicles, inside a building that is near a freeway, and inside a residence with an attached garage. Total motor vehicle emissions are taken from the EMFAC model. The 15 million people in the South Coast inhale 0.0048% of primary, nonreactive compounds emitted into the basin by motor vehicles. Intake of motor vehicle emissions is 46% higher than the average ambient concentration times the average breathing rate, because of microenvironments and because of temporal and spatial correlation among breathing rates, concentrations, and population densities. Intake fraction (iF) summarizes the emissions-to-intake relationship as the ratio of population intake to total emissions. iF is a population level exposure metric that incorporates spatial, temporal, and interindividual variability in exposures. iFs can facilitate the calculation of population exposures by distilling complex emissions-transport-receptor relationships. The author demonstrates this point by predicting …
Date: May 1, 2002
Creator: Marshall, Julian D.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Cathodic arc plasma deposition (open access)

Cathodic arc plasma deposition

None
Date: May 30, 2002
Creator: Anders, Andre
Object Type: Article
System: The UNT Digital Library
Systematics of Fission-Product Yields (open access)

Systematics of Fission-Product Yields

None
Date: May 5, 2002
Creator: A.C.Wahl
Object Type: Report
System: The UNT Digital Library
Special relative permeability functions with analytical solutions for transient flow into unsaturated rock matrix (open access)

Special relative permeability functions with analytical solutions for transient flow into unsaturated rock matrix

None
Date: May 28, 2002
Creator: Wu, Yu-Shu & Pan, Lehua
Object Type: Article
System: The UNT Digital Library
Field Investigation of Flow Processes Associated with Infiltration into an Initially Dry Fracture Network at Fran Ridge, Yucca Mountain, Nevada: A Photo Essay and Data Summary (open access)

Field Investigation of Flow Processes Associated with Infiltration into an Initially Dry Fracture Network at Fran Ridge, Yucca Mountain, Nevada: A Photo Essay and Data Summary

None
Date: May 1, 2002
Creator: Glass Jr., Robert J. & Nicholl, M. J.
Object Type: Report
System: The UNT Digital Library
Observation of high energy atmospheric neutrinos with antarctic muon and neutrino detector array (open access)

Observation of high energy atmospheric neutrinos with antarctic muon and neutrino detector array

The Antarctic Muon and Neutrino Detector Array (AMANDA) began collecting data with ten strings in 1997. Results from the first year of operation are presented. Neutrinos coming through the Earth from the Northern Hemisphere are identified by secondary muons moving upward through the array. Cosmic rays in the atmosphere generate a background of downward moving muons, which are about 10{sup 6} times more abundant than the upward moving muons. Over 130 days of exposure, we observed a total of about 300 neutrino events. In the same period, a background of 1.05 x 10{sup 9} cosmic ray muon events was recorded. The observed neutrino flux is consistent with atmospheric neutrino predictions. Monte Carlo simulations indicate that 90 percent of these events lie in the energy range 66 GeV to 3.4 TeV. The observation of atmospheric neutrinos consistent with expectations establishes AMANDA-B10 as a working neutrino telescope.
Date: May 7, 2002
Creator: Ahrens, J.; Andres, E.; Bai, X.; Barouch, G.; Barwick, S. W.; Bay, R. C. et al.
Object Type: Article
System: The UNT Digital Library
Investigations and Recommendations on the Use of Existing Experiments in Criticality Safety Analysis of Nuclear Fuel Cycle Facilities for Weapons-Grade Plutonium (open access)

Investigations and Recommendations on the Use of Existing Experiments in Criticality Safety Analysis of Nuclear Fuel Cycle Facilities for Weapons-Grade Plutonium

Sensitivity and Uncertainty (S/U) methods, recently developed at Oak Ridge National Laboratory (ORNL) have been demonstrated to determine the applicability of critical benchmark experiments to the criticality code validation of design systems. These methods, although still under development, have been recently published in several sources. Development of the techniques used in this report was conducted through joint support from the United States Department of Energy (U.S. DOE) and the Nuclear Regulatory Commission (NRC) to provide a physics-based approach for the establishment of the area of applicability of critical experiments per the requirements of ANSI/ANS-8.1. Use of these methods may allow users to interpolate and extrapolate the traditional area of applicability (AOA) of a given set of critical experiments to include new application areas that may not have been anticipated during the experiment design. The new S/U analytical tools include the SEN1 and SEN3 sensitivity analysis sequences, which will be available with the next release of the Standardized Computer Analyses for Licensing Evaluation (SCALE) code system. These analysis sequences compute the relative change in the system neutron multiplication factor, k{sub eff}, which would be observed for perturbations in the group-wise neutron cross-section data for each reaction of each nuclide in the …
Date: May 29, 2002
Creator: Rearden, B. T. & Elam, K. R.
Object Type: Report
System: The UNT Digital Library
Evolution of Pulse Shapes During Compressor Scans in a Cpa System and Control of Electron Acceleration in Plasmas (open access)

Evolution of Pulse Shapes During Compressor Scans in a Cpa System and Control of Electron Acceleration in Plasmas

The skewness of the envelope function of 20 - 100 femtosecond Ti:sapphire laser pulses has been controlled by appropriate choice of the higher order special phase coefficients, and used for optimization of a plasma wakefield electron accelerator.
Date: May 12, 2002
Creator: Toth, Csaba; de Groot, Joeri; van Tilborg, Jeroen; Geddes, Cameron G. R.; Faure, Jerome; Catravas, Palma et al.
Object Type: Article
System: The UNT Digital Library
PTAGIS Annual Progress Report, 2001-2002. (open access)

PTAGIS Annual Progress Report, 2001-2002.

This is the annual report for the PTAGIS project. February 28, 2002 marked the end of the 2001/02 PTAGIS fiscal year. All critical project activities progressed on schedule. However, a number of activities that have been traditionally performed by PTAGIS have been curtailed due to lack of resources. These reduced activities include production and distribution of the ''PTAGIS Newsletter'', development of a robust Web-based interface to PTAGIS data, curtailment efforts to upgrade critical database server hardware systems and processes and other activities. The main reasons for the lack of resources are: (1) In June, 2001, the region made a decision to expedite the installation of PIT tag detection at Bonneville and McNary dams. BPA issued contract 7422 to PSMFC to provide labor and material to install these systems. Nearly every PTAGIS resource was dedicated to this effort; (2) The Columbia Basin Fish and Wildlife Authority, Northwest Power Planning Council and Bonneville Power Administration have not solicited project proposals and budgets for over two years. Project requirements (represented in increasing scope, scale and complexity) have increased, but funding has not.
Date: May 1, 2002
Creator: Pacific States Marine Fisheries Commission
Object Type: Report
System: The UNT Digital Library
R&D of a Cyclone Melting Technology for Converting SPL to Useful Glass Fiber Products (open access)

R&D of a Cyclone Melting Technology for Converting SPL to Useful Glass Fiber Products

The objective of the project was to develop experimental data and evaluate the feasibility of converting SPL to commercial quality glass fiber and fluoride products using Vortec's CMS technology.
Date: May 17, 2002
Creator: Leonard M. Bartone, Jr.
Object Type: Report
System: The UNT Digital Library
Making Energy-Efficiency and Productivity Investments in Commercial Buildings: Choice of Investment Models (open access)

Making Energy-Efficiency and Productivity Investments in Commercial Buildings: Choice of Investment Models

This study examines the decision to invest in buildings and the types of investment decision rules that may be employed to inform the ''go--no go'' decision. There is a range of decision making tools available to help in investment choices, which range from simple rules of thumb such as payback periods, to life-cycle analysis, to decision theoretic approaches. Payback period analysis tends to point toward lower first costs, whereas life-cycle analysis tends to minimize uncertainties over future events that can affect profitability. We conclude that investment models that integrate uncertainty offer better explanations for the behavior that is observed, i.e., people tend to delay investments in technologies that life-cycle analysis finds cost-effective, and these models also lead to an alternative set of policies targeted at reducing of managing uncertainty.
Date: May 16, 2002
Creator: Jones, D.W.
Object Type: Report
System: The UNT Digital Library
Vacuum arc deposited DLC based coatings (open access)

Vacuum arc deposited DLC based coatings

The great interest in the use of diamond-like carbon (DLC) films as a coating material is justified by the superior wear resistance and hardness, chemical inertness, and very low friction coefficients of these coatings. Vacuum arc deposition is well suited to prepare superhard films with high sp{sup 3}/sp{sup 2} ratios. However, the high level of internal stresses originating during growth prevents the deposition of thick films, and their hardness makes it difficult for DLC layers to comply with substrate deformations. In order to overcome these limitations, different approaches are possible. Multilayer structures are one means to maintain the surface mechanical properties of the DLC while relieving the internal stresses. Another possibility is to dope the DLC films in order to reduce the internal stress and to stabilize the desirable sp{sup 3} bonds to higher temperatures. At higher doses of dopants, the formation of nanocrystals is possible and the properties of the coatings change drastically. All these approaches were investigated on films prepared by cathodic arc and a synthesis of the results is presented here.
Date: May 1, 2002
Creator: Monteiro, Othon R. & Delplancke-Ogletree, Marie-Paule
Object Type: Article
System: The UNT Digital Library
TECHNOLOGY TRANSFER TO U.S. INDEPENDENT OIL AND NATURAL GAS PRODUCERS (open access)

TECHNOLOGY TRANSFER TO U.S. INDEPENDENT OIL AND NATURAL GAS PRODUCERS

The Petroleum Technology Transfer Council (PTTC) continued pursuing its mission of helping U.S. independent oil and natural gas producers make timely, informed technology decisions. Networking opportunities that occur with a Houston Headquarters (HQ) location are increasing name awareness. Focused efforts by Executive Director Don Duttlinger to interact with large independents, national service companies and some majors are continuing to supplement the support base of the medium to smaller industry participants around the country. PTTC is now involved in many of the technology-related activities that occur in high oil and natural gas activity areas. Access to technology remains the driving force for those who do not have in-house research and development capabilities and look to the PTTC to provide services and options for increased efficiency. Looking forward to the future, the Board, Regional Lead Organization (RLO) Directors and HQ staff developed a 10-year vision outlining what PTTC needs to accomplish in supporting a national energy plan. This vision has been communicated to Department of Energy (DOE) staff and PTTC looks forward to continuing this successful federal-state-industry partnership. As part of this effort, several more examples of industry using information gained through PTTC activities to impact their bottom line were identified. Securing …
Date: May 31, 2002
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Thermal Regain From Displacement of Duct Leakage Within Insulation. (open access)

Thermal Regain From Displacement of Duct Leakage Within Insulation.

In one type of duct efficiency retrofit, additional insulation is added to a duct system that is already insulated. For example, a layer of R-4 insulation might be: added to a duct system that already has R-4 installed. It is possible that--either by chance or by design--the add-on layer, while not stopping duct leaks, might cause the leakage air to flow longitudinally for a distance, parallel to the duct, before it finds a way out of the newly added outer layer. This could happen by chance if the outer and inner layers of insulation have seams at different locations. Perhaps more usefully, if such longitudinal displacement of the leakage air turned out to be useful, it might be designed into the makeup of the outer insulation layer intended to be used in the retrofit. It is plausible that this leakage air might serve a useful function in keeping the insulation layer warmer (or, in the air-conditioning mode, cooler) than it would be in the absence of the leakage. By being held close to the ducts for a while, it might establish an artificially warmer (or cooler, in air conditioning) zone around the ducts. To the extent that this effect would …
Date: May 1, 2002
Creator: Andrews, J. W.
Object Type: Report
System: The UNT Digital Library
Tucannon River Spring Chinook Salmon Captive Broodstock Program, Annual Report 2001. (open access)

Tucannon River Spring Chinook Salmon Captive Broodstock Program, Annual Report 2001.

This report summarizes the objectives, tasks, and accomplishments of the Tucannon River spring chinook captive brood during 2001. The WDFW initiated a captive broodstock program in 1997. The overall goal of the Tucannon River captive broodstock program is for the short-term, and eventually long-term, rebuilding of the Tucannon River spring chinook salmon run, with the hope that natural production will sustain itself. The project goal is to rear captive salmon selected from the supplementation program to adults, spawn them, rear their progeny, and release approximately 150,000 smolts annually into the Tucannon River between 2003-2007. These smolt releases, in combination with the current hatchery supplementation program (132,000 smolts) and wild production, are expected to produce 600-700 returning adult spring chinook to the Tucannon River each year from 2005-2010. The captive broodstock program will collect fish from five (1997-2001) brood years (BY). The captive broodstock program was initiated with 1997 BY juveniles, and the 2001 BY fish have been selected. As of Jan 1, 2002, WDFW has 17 BY 1997, 159 BY 1998, 316 BY 1999, 448 BY 2000, and approximately 1,200 BY 2001 fish on hand at LFH. The 2001 eggtake from the 1997 brood year (Age 4) was 233,894 eggs …
Date: May 1, 2002
Creator: Gallinat, Michael P. & Bumgarner, Joseph D.
Object Type: Report
System: The UNT Digital Library
University reactor sharing program. Final technical report (open access)

University reactor sharing program. Final technical report

A table is given showing the participating institutions, numbers of students and faculty involved, the academic level, and a very brief description of the project or program.
Date: May 31, 2002
Creator: Holm, Richard L.
Object Type: Report
System: The UNT Digital Library
Atomic structure of highly-charged ions. Final report (open access)

Atomic structure of highly-charged ions. Final report

Atomic properties of multiply charged ions have been investigated using excitation of energetic heavy ion beams. Spectroscopy of excited atomic transitions has been applied from the visible to the extreme ultraviolet wavelength regions to provide accurate atomic structure and transition rate data in selected highly ionized atoms. High-resolution position-sensitive photon detection has been introduced for measurements in the ultraviolet region. The detailed structures of Rydberg states in highly charged beryllium-like ions have been measured as a test of long-range electron-ion interactions. The measurements are supported by multiconfiguration Dirac-Fock calculations and by many-body perturbation theory. The high-angular-momentum Rydberg transitions may be used to establish reference wavelengths and improve the accuracy of ionization energies in highly charged systems. Precision wavelength measurements in highly charged few-electron ions have been performed to test the most accurate relativistic atomic structure calculations for prominent low-lying excited states. Lifetime measurements for allowed and forbidden transitions in highly charged few-electron ions have been made to test theoretical transition matrix elements for simple atomic systems. Precision lifetime measurements in laser-excited alkali atoms have been initiated to establish the accuracy of relativistic atomic many-body theory in many-electron systems.
Date: May 23, 2002
Creator: Livingston, A. Eugene
Object Type: Report
System: The UNT Digital Library
Accurate estimation of the RMS emittance from single current amplifier data (open access)

Accurate estimation of the RMS emittance from single current amplifier data

This paper presents the SCUBEEx rms emittance analysis, a self-consistent, unbiased elliptical exclusion method, which combines traditional data-reduction methods with statistical methods to obtain accurate estimates for the rms emittance. Rather than considering individual data, the method tracks the average current density outside a well-selected, variable boundary to separate the measured beam halo from the background. The average outside current density is assumed to be part of a uniform background and not part of the particle beam. Therefore the average outside current is subtracted from the data before evaluating the rms emittance within the boundary. As the boundary area is increased, the average outside current and the inside rms emittance form plateaus when all data containing part of the particle beam are inside the boundary. These plateaus mark the smallest acceptable exclusion boundary and provide unbiased estimates for the average background and the rms emittance. Small, trendless variations within the plateaus allow for determining the uncertainties of the estimates caused by variations of the measured background outside the smallest acceptable exclusion boundary. The robustness of the method is established with complementary variations of the exclusion boundary. This paper presents a detailed comparison between traditional data reduction methods and SCUBEEx by …
Date: May 31, 2002
Creator: Stockli, Martin P.; Welton, R. F.; Keller, R.; Letchford, A. P.; Thomae, R. W. & Thomason, J. W. G.
Object Type: Article
System: The UNT Digital Library