Sonic decontamination (open access)

Sonic decontamination

The supersonic method of cleaning glassware is an outgrowth of the fact that it has been heretofore impossible to manually clean ground glass and quartz joints because the activity became lodged in the small pores of the ground surfaces. It has been theorized that the nature of the forces binding polonium to the glass is similar to that of the chemical bond but are less intense. The problem then becomes one of finding a force greater than this binding energy, capable of freeing the activity from the glass. This has been accomplished by using frequencies of 100 cycles to 20 kc at a power output from 2 to 20 watts, passing through a citric acid solution (pH-2) into which the contaminated article is placed. The optimum results, using a tank with the dimensions 7 in. {times} 7 in. {times} 7 in. and 3 liters of solution, has been found at 200 cycles or harmonics of 200 cycles. Citric acid was used because of the fact that it forms a soluble complex with polonium. The frequencies used have been kept within the sonic range until enough data has been obtained and correlated to warrant the design and construction of more costly …
Date: January 25, 1949
Creator: Brodbeck, R. M. & Schommer, G. R.
Object Type: Report
System: The UNT Digital Library
Gamma-ray array physics. (open access)

Gamma-ray array physics.

In this contribution I am going to discuss the development of large arrays of Compton Suppressed, High Purity Germanium (HpGe) detectors and the physics that has been, that is being, and that will be done with them. These arrays and their science have dominated low-energy nuclear structure research for the last twenty years and will continue to do so in the foreseeable future. John Sharpey Schafer played a visionary role in convincing a skeptical world that the development of these arrays would lead to a path of enlightenment. The extent to which he succeeded can be seen both through the world-wide propagation of ever more sophisticated devices, and through the world-wide propagation of his students. I, personally, would not be working in research if it were not for Johns inspirational leadership. I am eternally grateful to him. Many excellent reviews of array physics have been made in the past which can provide detailed background reading. The review by Paul Nolan, another ex-Sharpey Schafer student, is particularly comprehensive and clear.
Date: May 25, 1999
Creator: Lister, C. J.
Object Type: Article
System: The UNT Digital Library
Beam dynamics studies in a high-brightness photo-injector (open access)

Beam dynamics studies in a high-brightness photo-injector

A high-brightness photo-injector has been developed at Fermilab in collaboration with the TTF project at DESY. Two systems have been commissioned, one at DESY and one at Fermilab. The injector [1] consists of a 1.625-cell cavity RF gun, a superconducting niobium cavity (both 1.3 GHz), and a magnetic chicane. The gun is designed for an electric field of up to 50 MV/m on the cathode. Emittance compensation solenoids surround the gun to correct the linear space charge emittance growth. A high quantum efficiency Cs{sub 2}Te photocathode located in the first half-cell produces electrons when illuminated by 263 nm wavelength light (fourth harmonic of the Nd:YLF laser). The laser [2] was designed to produce a train of up to 800 equal amplitude, 10 {micro}J UV pulses spaced by 1 {micro}s at 1 Hz repetition rate. The laser pulse length is adjustable between 1 and 20 ps FWHM. The superconducting cavity is a 9-cell Nb structure fabricated by industry for TTF. It was tested with RF at DESY before being sent to Fermilab. At present, the cavity is operated at {approx}11 MeV/m. Beam measurements with the injector at Fermilab are in progress. Preliminary results for emittance and bunch length will be discussed …
Date: October 25, 1999
Creator: Carneiro, Jean-Paul
Object Type: Article
System: The UNT Digital Library
Questions of Identity (open access)

Questions of Identity

As an introduction to {nu}Fact '99, the ICFA/ECFA Workshop on Neutrino Factories Based on Muon Storage Rings, I place the issues of neutrino properties and neutrino oscillations in the broader context of fermion flavor.
Date: August 25, 1999
Creator: Quigg, Chris
Object Type: Article
System: The UNT Digital Library
Target rapidity baryon distributions in {sup 28}Si + {sup 197}Au and {sup 197}Au + {sup 197}Au collisions at 14.6 and 11.7 A{center_dot}GeV/c (open access)

Target rapidity baryon distributions in {sup 28}Si + {sup 197}Au and {sup 197}Au + {sup 197}Au collisions at 14.6 and 11.7 A{center_dot}GeV/c

Proton and deuteron kinetic energy spectra have been measured at target rapidities for both minimum bias and central collisions of 14.6 A{center_dot}GeV/c {sup 28}Si and 11.7 A{center_dot}GeV/c {sup 197}Au beams with a {sup 197}Au target. The spectra were measured from a low energy threshold of approximately E{sub kin}=35 MeV to well over 200 MeV for laboratory angles of 50{degree} to 130{degree} ({vert_bar}{eta}{vert_bar} {le}0.76). The acceptance-corrected spectra have been fit over a limited range of kinetic energies using a Boltzmann distribution. The integrated yields and the inverse slope parameters are presented as a function of centrality for the {sup 28}Si + {sup 197}Au reaction and as a function of trigger for the {sup 197}Au + {sup 197}Au reaction. These quantities are also compared with the proton spectra generated using both the ARC and RQMD codes.
Date: February 25, 1993
Creator: Sangster, T.C.; Costales, J.B.; Namboodiri, M.N. & Collaboration, E802
Object Type: Article
System: The UNT Digital Library
Emissions of greenhouse gases in the United States, 1987--1994 (open access)

Emissions of greenhouse gases in the United States, 1987--1994

The Energy Information Administration (EIA) is required by the Energy Policy Act of 1992 to prepare a report on aggregate US national emissions of greenhouse gases for the period 1987--1992, with annual updates thereafter. This is the third annual update report,covering national emissions over the period 1987--1993, with preliminary estimates of US carbon dioxide and halocarbon emissions for 1994. Calculating national aggregate emissions(or ``national inventories``) of greenhouse gases is a recently developed form of intellectual endeavor. Greenhouse gas emissions are rarely measured directly or reported to statistical agencies. Thus, to prepare emissions inventories usually requires inferring emissions indirectly from information collected for other purposes. Both the available information and the inferences drawn may be of varying reliability. Chapter 1 of this report briefly recapitulates some background information about global climate change and the greenhouse effect and discusses important recent developments in global climate change activities. Chapters 2 through 6 cover emissions of carbon dioxide, methane, nitrous oxide, halocarbons, and criteria pollutants, respectively. Chapter 7 describes potential sequestration and emissions of greenhouse gases as a result of land use changes.
Date: September 25, 1995
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Measurement of the light quark flavor asymmetry in the nucleon sea. (open access)

Measurement of the light quark flavor asymmetry in the nucleon sea.

Fermilab experiment E866 has performed a precision measurement of the ratio of Drell-Yan yields from 800 GeV/c protons incident on deuterium and hydrogen targets. The measurement is used to determine the ratio of down antiquarks({bar d}) to up antiquarks({bar u}) in the proton over a broad range in the fraction of the proton momentum carried by the antiquark, 0.02 < x < 0.345. For x < 0.15, the data is in reasonable agreement with pre-existing parton distributions while for x > 0.20 the data is much closer to unity than these parton functions had indicated. The light quark asymmetry provides valuable information on the relative role perturbative and non-perturbative mechanisms play in generating the nucleon sea. A proposal to extend the Drell-Yan measurement to higher values of x using 120 GeV protons from the Fermilab main injector will be discussed.
Date: June 25, 1999
Creator: Awes, T. C.; Beddo, M. E.; Brown, C. N.; Bush, J. D.; Collaboration, FNAL E866 /NuSea; Geesaman, D. F. et al.
Object Type: Article
System: The UNT Digital Library
The Physics of Fast Z Pinches (open access)

The Physics of Fast Z Pinches

The spectacular progress made during the last few years in reaching high energy densities in fast implosions of annular current sheaths (fast Z pinches) opens new possibilities for a broad spectrum of experiments, from x-ray generation to controlled thermonuclear fusion and astrophysics. Presently Z pinches are the most intense laboratory X ray sources (1.8 MJ in 5 ns from a volume 2 mm in diameter and 2 cm tall). Powers in excess of 200 TW have been obtained. This warrants summarizing the present knowledge of physics that governs the behavior of radiating current-carrying plasma in fast Z pinches. This survey covers essentially all aspects of the physics of fast Z pinches: initiation, instabilities of the early stage, magnetic Rayleigh-Taylor instability in the implosion phase, formation of a transient quasi-equilibrium near the stagnation point, and rebound. Considerable attention is paid to the analysis of hydrodynamic instabilities governing the implosion symmetry. Possible ways of mitigating these instabilities are discussed. Non-magnetohydrodynamic effects (anomalous resistivity, generation of particle beams, etc.) are summarized. Various applications of fast Z pinches are briefly described. Scaling laws governing development of more powerful Z pinches are presented. The survey contains 36 figures and more than 300 references.
Date: October 25, 1999
Creator: Ryutov, D. D.; Derzon, Mark S. & Matzen, M. Keith
Object Type: Article
System: The UNT Digital Library
Recent advances in fabrication of high-T{sub c} superconductors for electric power applications. (open access)

Recent advances in fabrication of high-T{sub c} superconductors for electric power applications.

The U.S. Department of Energy (DOE) supports an applied superconductivity program entitled ''Superconductivity Program for Electric Power Systems.'' Activities within this program contribute to development of the high-temperature superconductor (HTS) technology needed for industry to proceed with the commercial development of electric power applications such as motors, generators, transformers, transmission cables, and current limiters. Research is conducted in three categories: wire development, systems technology development, and Superconductivity Partnership Initiative (SPI). Wire development activities are devoted to improving the critical current density (J{sub c}) of short-length HTS wires, whereas systems technology development focuses on fabrication of long-length wires, coils, and on magnets. The SPI activities are aimed at development of prototype products. Significant progress has been made in the development of (HTSs) for various applications: some applications have already made significant strides in the marketplace, while others are still in the developmental stages. For successful electric power applications, it is very important that the HTS be fabricated into long-length conductors that exhibit desired superconducting and mechanical properties. Several parameters of the PIT technique must be carefully controlled to obtain the desired properties. Long lengths of Bi-2223 tapes with respectable superconducting properties have been fabricated by a carefully designed thermomechanical treatment process. …
Date: March 25, 1998
Creator: Balachandran, U.
Object Type: Article
System: The UNT Digital Library
Monthly energy review, September 1995 (open access)

Monthly energy review, September 1995

An ``energy snapshot`` article is included on housing characteristics in 1993 (survey of 7,111 households). The rest of the document is divided into: energy overview, energy consumption, petroleum, natural gas, oil and gas resource development, coal, electricity, nuclear energy, energy prices, international energy, and appendices (conversion factors, CO2 emission factors from coal, index, glossary).
Date: September 25, 1995
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Magnetic bearing update (open access)

Magnetic bearing update

Stabilization of whirl instability by floppy, viscous bearing mounts is discussed and required material properties are estimated for the new tilt-whirl mode in eddy-current stabilized magnetic bearings. A relatively low Young`s modules Y {approximately} 10{sup 5} and high viscosity {zeta} {approximately} 10{sup 7} are required (both in MKS units), suggesting the need for careful mounting design. New information on periodic bearings shows that, thus far, Earshaw`s Theorem cannot be defeated by periodicity, despite the author`s earlier claims.
Date: May 25, 1995
Creator: Fowler, T.K.
Object Type: Report
System: The UNT Digital Library
Atmospheric test models and numerical experiments for the simulation of the global distribution of weather data transponders (open access)

Atmospheric test models and numerical experiments for the simulation of the global distribution of weather data transponders

A proposal has been made to establish a high density global network of atmospheric micro transponders to record time, temperature, and wind data with time resolution of {le} 1 minute, temperature accuracy of {+-} 1 K, spatial resolution no poorer than {approx}3km horizontally and {approx}0.1km vertically, and 2-D speed accuracy of {le} 1m/s. This data will be used in conjunction with advanced numerical weather prediction models to provide increases in the reliability of long range weather forecasts. Major advances in data collection technology will be required to provide the proposed high-resolution data collection network. Systems studies must be undertaken to determine insertion requirements, spacing, and evolution of the transponder ensemble, which will be used to collect the data. Numerical models which provide realistic global weather pattern simulations must be utilized in order to perform these studies. A global circulation model with a 3{sup o} horizontal resolution has been used for initial simulations of the generation and evolution of transponder distributions. These studies indicate that reasonable global coverage of transponders can be achieved by a launch scenario consisting of the sequential launch of transponders at specified heights from a globally distributed set of launch sites.
Date: August 25, 1999
Creator: Grossman, A & Molenkamp, C R
Object Type: Report
System: The UNT Digital Library
Fracture and Creep of an Al{sub 2}O{sub 3}-SiC(whisker)-TiC(particle) Composite. (open access)

Fracture and Creep of an Al{sub 2}O{sub 3}-SiC(whisker)-TiC(particle) Composite.

High-temperature fracture strength and compressive creep of an electrodischarge-machinable composite, Al{sub 2}O{sub 3}-30.9 vol.% SiC whiskers-23 vol.% TiC particles have been studied to 1200 C and 1450 C, respectively, in inert atmosphere. Microstructures of fractured and deformed specimens were examined by scanning and transmission electron microscopy. Fast fracture occurred at T {le} 1200 C. Steady-state creep was achieved for T > 1350 C at stresses < 80 MPa, with the rate-controlling mechanism being partially unaccommodated grain-boundary sliding, with a stress exponent of {approx}1 and an activation energy of {approx}470 kJ/mol.
Date: February 25, 1998
Creator: de Arellano-Lopez, A. R.
Object Type: Article
System: The UNT Digital Library
Reproducible measurements of MPI performance characteristics. (open access)

Reproducible measurements of MPI performance characteristics.

In this paper we describe the difficulties inherent in making accurate, reproducible measurements of message-passing performance. We describe some of the mistakes often made in attempting such measurements and the consequences of such mistakes. We describe mpptest, a suite of performance measurement programs developed at Argonne National Laboratory, that attempts to avoid such mistakes and obtain reproducible measures of MPI performance that can be useful to both MPI implementers and MPI application writers. We include a number of illustrative examples of its use.
Date: June 25, 1999
Creator: Gropp, W. & Lusk, E.
Object Type: Article
System: The UNT Digital Library
Advanced Reservoir Characterization in the Antelope Shale to Establish the Viability of C02 Enhanced Oil Recovery in California's Monterey Formation Siliceous Shales (open access)

Advanced Reservoir Characterization in the Antelope Shale to Establish the Viability of C02 Enhanced Oil Recovery in California's Monterey Formation Siliceous Shales

The primary objective of this research is to conduct advanced reservoir characterization and modeling studies in the Antelope Shale reservoir. Characterization studies will be used to determine the technical feasibility of implementing a CO2 enhanced oil recovery project in the Antelope Shale in Buena Vista Hills Field. The Buena Vista Hills pilot CO2 project will demonstrate the economic viability and widespread applicability of CO2 flooding in fractured siliceous shale reservoirs of the San Joaquin Valley. The research consists of four primary work processes: Reservoir Matrix and Fluid Characterization; Fracture Characterization; Reservoir Modeling and Simulation; and CO2 Pilot Flood and Evaluation. Work done in these areas is subdivided into two phases or budget periods. The first phase of the project will focus on the application of a variety of advanced reservoir characterization techniques to determine the production characteristics of the Antelope Shale reservoir. Reservoir models based on the results of the characterization work will be used to evaluate how the reservoir will respond to secondary recovery and EOR processes. The second phase of the project will include the implementation and evaluation of an advanced enhanced oil recovery (EOR) pilot in the West Dome of the Buena Vista Hills Field.
Date: April 25, 1997
Creator: Morea, Michael F.
Object Type: Report
System: The UNT Digital Library
Preflame Zone Structure and Main Features of Fuel Conversion in Atmospheric Pressure Premixed Laminar Hydrocarbon Flames (open access)

Preflame Zone Structure and Main Features of Fuel Conversion in Atmospheric Pressure Premixed Laminar Hydrocarbon Flames

This report describes the structure study of the premixed hydrocarbon-oxidizer Bunsen flames burning at the atmospheric pressure and also the ones with some inhibitors added. Studies were performed on hexane, propane, methane, acetylene, and hexene flames.
Date: August 25, 1995
Creator: Ksandopulo, G. I.
Object Type: Report
System: The UNT Digital Library
The efficacy of oxidative coupling for promoting in-situ immobilization of hydroxylated aromatics in contaminated soil and sediment systems. Progress report, September 15, 1996--September 14, 1997 (open access)

The efficacy of oxidative coupling for promoting in-situ immobilization of hydroxylated aromatics in contaminated soil and sediment systems. Progress report, September 15, 1996--September 14, 1997

'The principal objective for Year 1 of this study has included sorbent collection, preparation and characterization, as well as investigation of the efficacy of abiotic/enzymatic coupling reactions on the irreversible binding of phenolic compounds on natural soils and sediments. In response to a budget reduction request specific modifications were made without compromising the integrity of the proposed work. The modified Phase 1 experimental matrix consists of four natural sorbents and three phenolic sorbates. Preliminary experiments with Chelsea soil indicated excessive release of soil organic matter (SOM) into solution, thereby complicating determination of aqueous phase phenol concentrations. It was therefore decided to substitute Lachine shale for the Chelsea soil. This shale is a well-characterized natural sorbent used previously in the laboratory. Additionally two field soils having similar soil morphology were identified based on their particle size distribution and organic matter content. These soils were located from US Department of Agriculture soil survey data and collected aseptically from a forested and a grassland site. Another deviation from the proposed schedule of tasks was the initiation of work from Phase 2 and Phase 3. In addition to experiments with natural systems, preliminary work with model and engineered systems was initiated earlier than scheduled …
Date: August 25, 1997
Creator: Weber, W.J. Jr. & Bhandari, A.
Object Type: Report
System: The UNT Digital Library
Cable tracking system proposal (open access)

Cable tracking system proposal

The Experimental Facilities Division requires a labeling system to identify and catalog the instrumentation, control, and computer cables that will run throughout the building. Tom Sheridan from the MIS Group has already made some general suggestions about the information that could be included in an Oracle-based Cable Tracking System (E-mail text distributed by Gary Gunderson on the 27th of August). Glenn Decker`s LS Note No. 191 is also relevant to the subject since it addresses name assignment rules for the storage ring devices. The intent of this note is to recommend a mechanism for tracking wires/cables, with enough specifics, to which all groups in the Division would adhere when pulling cables. Because most cables will run between various beamline devices, hutch safety components, and equipment racks, any method of tracking cables is related to the Equipment Tracking System. That system has been developed by the APS Project personnel and is described in the APS Project Equipment Tracking System Guidelines (DRAFT). It can be adopted to XFD`s needs. Two essential features of the Cable Tracking System are: 1) Each cable shell have a unique Identifier, and 2) Cable label must contain information that is helpful during troubleshooting in the field. The …
Date: June 25, 1993
Creator: Friedman, N.
Object Type: Report
System: The UNT Digital Library
High charge short electron bunches for wakefield accelerator structures development. (open access)

High charge short electron bunches for wakefield accelerator structures development.

The Argonne Wakefield Accelerator group develops accelerating structures based on dielectric loaded waveguides. We use high charge short electron bunches to excite wakefields in dielectric loaded structures, and a second (low charge) beam to probe the wakefields left behind by the drive beam. We report measurements of beam parameters and also initial results of the dielectric loaded accelerating structures. We have studied acceleration of the probe beam in these structures and we have also made measurements on the RF pulses that are generated by the drive beam. Single drive bunches, as well as multiple bunches separated by an integer number of RF periods have been used to generate the accelerating wakefields.
Date: September 25, 1998
Creator: Conde, M. E.
Object Type: Article
System: The UNT Digital Library
High Voltage GaN Schottky Rectifiers (open access)

High Voltage GaN Schottky Rectifiers

Mesa and planar GaN Schottky diode rectifiers with reverse breakdown voltages (V{sub RB}) up to 550V and >2000V, respectively, have been fabricated. The on-state resistance, R{sub ON}, was 6m{Omega}{center_dot} cm{sup 2} and 0.8{Omega}cm{sup 2}, respectively, producing figure-of-merit values for (V{sub RB}){sup 2}/R{sub ON} in the range 5-48 MW{center_dot}cm{sup -2}. At low biases the reverse leakage current was proportional to the size of the rectifying contact perimeter, while at high biases the current was proportional to the area of this contact. These results suggest that at low reverse biases, the leakage is dominated by the surface component, while at higher biases the bulk component dominates. On-state voltages were 3.5V for the 550V diodes and {ge}15 for the 2kV diodes. Reverse recovery times were <0.2{micro}sec for devices switched from a forward current density of {approx}500A{center_dot}cm{sup -2} to a reverse bias of 100V.
Date: October 25, 1999
Creator: Cao, X. A.; Cho, H.; Chu, S. N. G.; Chuo, C. C.; Chyi, J. I.; Dang, G. T. et al.
Object Type: Article
System: The UNT Digital Library
Radiological monitoring plan for the Oak Ridge Y-12 Plant: Surface water (open access)

Radiological monitoring plan for the Oak Ridge Y-12 Plant: Surface water

National Pollutant Discharge Elimination System (NPDES) Permit TN0002968, issued April 28, 1995, requires that the Y-12 Plant Radiological Monitoring Plan for surface water be modified (Part 111-H). These modifications shall consist of expanding the plan to include storm water monitoring and an assessment of alpha, beta, and gamma emitters. In addition, a meeting was held with personnel from the Tennessee Department of Environment and Conservation (TDEC) on May 4, 1995. In this meeting, TDEC personnel provided guidance to Y-12 Plant personnel in regard to the contents of the modified plan. This report contains a revised plan incorporating the permit requirements and guidance provided by TDEC personnel. In addition, modifications were made to address future requirements of the new regulation for radiation protection of the public and the environment in regards to surface water monitoring.
Date: July 25, 1995
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Impact of mental representational systems on design interface. (open access)

Impact of mental representational systems on design interface.

The purpose of the studies conducted at Argonne National Laboratory is to understand the impact mental representational systems have in identifying how user comfort parameters influence how information is to best be presented. By understanding how each individual perceives information based on the three representational systems (visual, auditory and kinesthetic modalities), it has been found that a different approach must be taken in the design of interfaces resulting in an outcome that is much more effective and representative of the users mental model. This paper will present current findings and future theories to be explored.
Date: February 25, 1998
Creator: Brown-VanHoozer, S. A.
Object Type: Article
System: The UNT Digital Library
Atom-by-Atom and Concerted Hopping of Adatom Pairs on an Open Metal Surface (open access)

Atom-by-Atom and Concerted Hopping of Adatom Pairs on an Open Metal Surface

Atom-by-atom and concerted hopping of ad-dimers on the open (100) surface of fcc metals are studied by means of density-functional calculations. The adatom interaction is relatively short-ranged, and beyond next-nearest neighbors ad-dimers are effectively dissociated. Diffusion takes place by a simple shearing process, favored because it maximizes adatom coordination at the transition state This holds for Al, Au, and Rh, and is likely a general result because geometrical arguments dominate over details of the electronic structure.
Date: August 25, 1999
Creator: Bogicevic, A.; Ovesson, S.; Lundqvist, B. I. & Jennison, D. R.
Object Type: Article
System: The UNT Digital Library
HFBR: Review of the technical specifications against the FSAR (open access)

HFBR: Review of the technical specifications against the FSAR

The purpose of this review is to determine the adequacy of the High Flux Beam Reactor (HFBR) Technical Specifications for 40 MW operation by comparison with the HFBR Final Safety Analysis Report, particularly the accident analyses chapter. Specifically, the Technical Specifications were compared against the Design Basis Accident (DBA) Analyses presented in the Addendum to the HFBR FSAR for 60 MW Operation. The 60 MW DBA analyses was used since it is more current and complete than the analyses presented in the original FSAR which is considered obsolete. A listing of the required systems and equipment was made for each of the accidents analyzed. Additionally, the Technical Specification instrument setpoints were compared to the DBA analyses parametric values. Also included in this review was a comparison of the Technical Specification Bases against the FSAR and the identification of any differences. The HFBR Operations Procedures Manual (OPM) was also reviewed for any inconsistencies between the FSAR or the Technical Specifications. Upon completion of this review it was determined that the Technical Specifications are well written and the items commented on should not delay the low power restart (40 MW). Additionally, the OPM is also well written and does not require further …
Date: January 25, 1990
Creator: Rao, D. V.; Ross, S. B.; Claiborne, E. R.; Darby, J. L. & Clark, R. A.
Object Type: Report
System: The UNT Digital Library