Hydrogen Release from Irradiated Vanadium Alloy V-4Cr-4Ti (open access)

Hydrogen Release from Irradiated Vanadium Alloy V-4Cr-4Ti

The present work is an attempt to obtain data concerning the influence of neutron and ? irradiation upon hydrogen retention in V-4Cr-4Ti vanadium alloy. The experiments on in-pile loading of vanadium alloy specimens at the neutron flux density 1014 n/cm2s, hydrogen pressure of 80 Pa, and temperatures of 563, 613, and 773 K were carried out using the IVG.1M reactor of the Kazakhstan National Nuclear Center. A preliminary set of loading/degassing experiments with non-irradiated material has been carried out to obtain data on hydrogen interaction with vanadium alloy. The, data presented in this work are related both to non-irradiated and irradiated samples.
Date: September 1, 1999
Creator: Klepikov, A. Kh.; Romanenko, O. G.; Chikhray, E. V.; Tazhibaeva, I. L.; Shestakov, V. P. & Longhurst, Glen Reed
System: The UNT Digital Library
CHARACTERIZATION OF THE COHERENT NOISE, ELECTROMAGNETIC COMPATIBILITY AND ELECTROMAGNETIC INTERFERENCE OF THE ATLAS EM CALORIMETER FRONT END BOARD (open access)

CHARACTERIZATION OF THE COHERENT NOISE, ELECTROMAGNETIC COMPATIBILITY AND ELECTROMAGNETIC INTERFERENCE OF THE ATLAS EM CALORIMETER FRONT END BOARD

The ATLAS Electromagnetic (EM) calorimeter (EMCAL) Front End Board (FEB) will be located in custom-designed enclosures solidly connected to the feedtroughs. It is a complex mixed signal board which includes the preamplifier, shaper, switched capacitor array analog memory unit (SCA), analog to digital conversion, serialization of the data and related control logic. It will be described in detail elsewhere in these proceedings. The electromagnetic interference (either pick-up from the on board digital activity, from power supply ripple or from external sources) which affects coherently large groups of channels (coherent noise) is of particular concern in calorimetry and it has been studied in detail.
Date: September 20, 1999
Creator: CHASE,B. CITTERIO,M. LANNI,F. MAKOWIECKI,D. RADEKA,S. RESCIA,S. TAKAI,H. ET AL.
System: The UNT Digital Library
High field solenoids for muon cooling (open access)

High field solenoids for muon cooling

The proposed cooling system for the muon collider will consist of a 200 meter long line of alternating field straight solenoids interspersed with bent solenoids. The muons are cooled in all directions using a 400 mm long section liquid hydrogen at high field. The muons are accelerated in the forward direction by about 900 mm long, 805 MHz RF cavities in a gradient field that goes from 6 T to -6 T in about 300 mm. The high field section in the channel starts out at an induction of about 2 T in the hydrogen. As the muons proceed down the cooling channel, the induction in the liquid hydrogen section increases to inductions as high as 30 T. The diameter of the liquid hydrogen section starts at 750 mm when the induction is 2 T. As the induction in the cooling section goes up, the diameter of the liquid hydrogen section decreases. When the high field induction is 30 T, the diameter of the liquid hydrogen section is about 80 mm. When the high field solenoid induction is below 8.5 T or 9T, niobium titanium coils are proposed for generating .the magnetic field. Above 8.5 T or 9 T to …
Date: September 8, 1999
Creator: Green, M. A.; Eyssa, Y.; Kenny, S.; Miller, J. R. & Prestemon, S.
System: The UNT Digital Library
Use of fish community data to evaluate restoration success of a riparian stream. (open access)

Use of fish community data to evaluate restoration success of a riparian stream.

Abstract From 1985 to 1988, stream and riparian habitats in Pen branch and Four Mile branch began recovering from deforestation caused by the previous release of hot water from nuclear reactors. The Pen branch corridor was replanted with wetland trees in 1995 to expedite recovery and restore the Pen branch ecosystem. Pen branch, Four Mile branch, and two relatively undisturbed streams were electrofished in 1995:1996 to determine how fish assemblages differed between the previously disturbed and undisturbed streams and whether such difference could be used to measure restoration success in Pen branch. Fish assemblages were analyzed using nonparametric multivariate statistical methods and the index of biotic integrity (IBI), a bioassessment method based on measurement of ecologically sensitive characteristics of fish assemblages. Many aspects of fish assemblage structure (e.g. species richness, disease incidence, taxonomic composition at the family level) did not differ between disturbed and undisturbed streams; however, the disturbed streams were characterized by higher densities of a number of species. These differences were successfully detected with the multivariate statistical methods; whereas, the IBI did not differ between most recovering and undisturbed sampling sites. Because fish assemblages are strongly influenced by instream habitat, and because instream habitat is strongly influenced by …
Date: September 1, 1999
Creator: Paller, Michael, H.; Reichert, Marcel, J.M.; Dean, John, M. & Seigle, John, C.
System: The UNT Digital Library
The design and construction of a gradient solenoid for the high powered RF cavity experiment for the muon collider (open access)

The design and construction of a gradient solenoid for the high powered RF cavity experiment for the muon collider

This report describes the construction and test of a split solenoid that has a warm bore of 440 mm and a cryostat length of 1088 mm. (A 750 mm section contains the magnetic field.) When the coils are hooked so the fields are additive, the central induction is 5.0 T at its design current. When the coils are hooked so that the fields are in opposition, the induction at the center of the solenoid is zero and the peak induction on the solenoid axis is {+-}3.7 T. The on-axis induction gradient is 25 T per meter when the coils are hooked in opposition. When the coils are operated at their design currents in opposition, the force pushing the two coils apart is about 3 MN. The force pushing the coils apart is carried by the aluminum coil mandrel and a solid aluminum sheath outside of the superconducting winding. The coil was wound as a wet lay-up coil using alumina filled epoxy (Stycast). A layer of hard aluminum wire wound on the outside of the superconducting coil carries some of the hoop forces and limits the strain so that training does not occur. At design current, at both polarities, the peak …
Date: September 5, 1999
Creator: Green, M. A.; Chen, J. Y. & Wang, S. T.
System: The UNT Digital Library
Proceedings of the 21st Seismic Research Symposium: Technologies for Monitoring The Comprehensive Nuclear Test-Ban Treaty (open access)

Proceedings of the 21st Seismic Research Symposium: Technologies for Monitoring The Comprehensive Nuclear Test-Ban Treaty

These proceedings contain papers prepared for the 21st Seismic Research Symposium: Technologies for Monitoring The Comprehensive Nuclear-Test-Ban Treaty, held 21-24 September 1999 in Las Vegas, Nevada. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Defense Threat Reduction Agency (DTRA), Air Force Technical Applications Center (AFTAC), Department of Defense (DoD), the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.
Date: September 21, 1999
Creator: Warren, N. Jill
System: The UNT Digital Library
A design for a combined function superconducting dipole for a muon collider FFAG accelerator (open access)

A design for a combined function superconducting dipole for a muon collider FFAG accelerator

The acceleration stages for a muon collider require that the muons be accelerated within a given ring in fewer than twenty turns. One type of accelerator that appears to be attractive for a synchrotron that accelerates the muon a factor of four in energy in a few turns is the Fixed Field Alternating Gradient (FFAG) type of accelerator. As the energy of the muon beam increases, the muons move toward a higher field region of a DC combined function dipole. The following dipole and quadrupole magnet characteristics are required for a muon FFAG machine to be successful: (1) The dipole will be a fixed field dipole with an impressed quadrupole and sextupole field. There may or may not be separate quadrupoles that mayor may not have added sextupole windings. (2) The horizontal aperture of the required good field region is wider than the vertical aperture of the required good field region. (3) The magnet is relatively short, so that the conventional SSC type of superconducting dipole or quadrupole ends can not be used. The field at the end of the magnet must fall off abruptly within the distance of less than one vertical aperture. For a magnet that is 400 …
Date: September 10, 1999
Creator: Green, Michael A.
System: The UNT Digital Library
Superconducting solenoids for the Muon collider (open access)

Superconducting solenoids for the Muon collider

The muon collider is a new idea for lepton colliders. The ultimate energy of an electron ring is limited by synchrotron radiation. Mouns, which have a rest mass that is 200 times that of an electron can be stored at much higher energies before synchrotron radiation limits ring performance. The problem with muon is their short lifetime (2.1 microseconds at rest). In order to operate a muon storage ring large numbers of muon must be collected, cooled and accelerated before they decay to an electron and two neutrinos. As we see it now, high field superconducting solenoids are an integral part of a muon coUider muon production and cooling systems. This report will describe the design parameters for superconducting and hybrid solenoids that are used for pion production and collection, RF phase rotations of the pions as they decay into muons and the muon cooling (reduction of the muon emittance) before acceleration.
Date: September 23, 1999
Creator: Green, M. A.; Eyssa, Y.; Kenny, S.; Miller, J. R.; Prestemon, S. & Weggel, R. J.
System: The UNT Digital Library
Wilson loops in large N theories (open access)

Wilson loops in large N theories

None
Date: September 1, 1999
Creator: Ooguri, H.
System: The UNT Digital Library
Demonstration of a Universal Solvent Extraction Process for the Separation of Cesium and Strontium from Actual Acidic Tank Waste at the INEEL (open access)

Demonstration of a Universal Solvent Extraction Process for the Separation of Cesium and Strontium from Actual Acidic Tank Waste at the INEEL

A universal solvent extraction process is being evaluated for the simultaneous separation of Cs, Sr, and the actinides from acidic high-activity tank waste at the Idaho National Engineering and Environmental Laboratory (INEEL) with the goal of minimizing the high-activity waste volume to be disposed in a deep geological repository. The universal solvent extraction process is being developed as a collaborative effort between the INEEL and the Khlopin Radium Institute in St. Petersburg, Russia. The process was recently demonstrated at the INEEL using actual radioactive, acidic tank waste in 24 stages of 2-cm diameter centrifugal contactors located in a shielded cell facility. With this testing, removal efficiencies of 99.95%, 99.985%, and 95.2% were obtained for 137 Cs, 90 Sr, and total alpha, respectively. This is sufficient to reduce the activities of 137 Cs and 90 Sr to below NRC Class A LLW requirements. The total alpha removal efficiency was not sufficient to reduce the activity of the tank waste to below NRC Class A non-TRU requirements. The lower than expected removal efficiency for the actinides is due to loading of the Ph2Bu2CMPO in the universal solvent exiting the actinide strip section and entering the wash section resulted in the recycle of …
Date: September 1, 1999
Creator: Law, Jack Douglas; Herbst, Ronald Scott; Todd, Terry Allen; Brewer, Ken Neal; Romanovskiy, V. N.; Esimantovskiy, V. M. et al.
System: The UNT Digital Library
Crack Growth Monitoring in Harsh Environments by Electric Potential Measurements (open access)

Crack Growth Monitoring in Harsh Environments by Electric Potential Measurements

Electric potential measurement (EPM) technology offers an attractive alternative to conventional nondestructive evaluation (NDE) for monitoring crack growth in harsh environments. Where conventional NDE methods typically require localized human interaction, the EPM technique developed at the Idaho National Engineering and Environmental Laboratory (INEEL) can be operated remotely and automatically. Once a crack-like defect is discovered via conventional means, EPM can be applied to monitor local crack size changes. This is of particular interest in situations where an identified structural defect is not immediately rejectable from a fitness-for-service viewpoint, but due to operational and environmental conditions may grow to an unsafe size with continuing operation. If the location is in a harsh environment where periodic monitoring by normal means is either too costly or not possible, a very expensive repair may be immediately mandated. However, the proposed EPM methodology may offer a unique monitoring capability that would allow for continuing service. INEEL has developed this methodology, supporting equipment, and calibration information to apply EPM in a field environment for just this purpose. Laboratory and pilot scale tests on full-size engineering structures (pressure vessels and piping) have been successfully performed. The technique applicable is many severe environments because the sensitive equipment (electronics, …
Date: September 1, 1999
Creator: Lloyd, Wilson Randolph; Reuter, Walter Graham & Weinberg, David Michael
System: The UNT Digital Library
Critical Properties of Polydisperse Fluid Mixtures From Anequation of State (open access)

Critical Properties of Polydisperse Fluid Mixtures From Anequation of State

Based on stability theory for plydisperse fluid mixtures, expressions have been developed for the spinodal criterion, critical criterion and various stability tests for systems containing one discrete component and one continuous homologue. Each criterion can be separated into two parts: the first part is the same in form as that for binary systems; when we assume particular mixing rules for parameters of the equation of state, that part is determined only by the average molar mass of the homologue. The second part is concerned with the distribution function that characterizes the continuous component. To illustrate results, the van der Waals equation of state is used to calculate critical properties; the composition dependences of parameters a$sup 1/2$ and b of the van der Waals equation are assumed to be linear functions of molar mass. Numerical results for the critical loci are obtained. For a discrete component i and a continuous component j, systematic variations of parameters in the distribution function for j or of the interaction parameter$sub ij$ show transitions between qualitatively different types of phase behavior.
Date: September 1, 1999
Creator: Cai, J.; Liu, H.; Hu, Y. & Prausnitz, J.M.
System: The UNT Digital Library
Preliminary Environmental Flow and Transport Modeling at the INEEL (open access)

Preliminary Environmental Flow and Transport Modeling at the INEEL

The Idaho National Engineering and Environmental Laboratory (INEEL) is located in southeastern Idaho in the USA. The primary mission since the laboratory was founded in 1949 has been nuclear reactor research. Fifty-two reactors have been built and operated on the INEEL. Other principal activities at the laboratory have been reprocessing of spent nuclear fuel. Low-level radioactive waste generated on site and mixed and transuranic waste from the Rocky Flats plutonium processing facility in Colorado has been disposed on the INEEL at the Radioactive Waste Management Complex (RWMC). Waste disposal at the RWMC began in 1952 with shallow land burial in pits and trenches. The INEEL was placed on the National Priorities List (NPL) in 1989. The resulting environmental assessments of the potential negative health impacts of disposed waste at the RWMC have required the use of predictive numerical simulations. A petroleum reservoir simulator called TETRAD was modified for use in simulating environmental flow and transport. Use of this code has allowed the complex subsurface stratigraphy to be simulated, including an extensive region of unsaturated fractured basalt. Dual continual simulation approaches have been used to assess combined aqueous- and gaseous-phase transport of volatile organic compounds as well as dissolved-phase transport of …
Date: September 1, 1999
Creator: Magnuson, Swen O; Mccarthy, James Michael & Navratil, James Dale
System: The UNT Digital Library
Installation of the Irradiation Test Vehicle in the Advanced Test Reactor (open access)

Installation of the Irradiation Test Vehicle in the Advanced Test Reactor

The Irradiation Test Vehicle (ITV) was installed in the Department of Energy’s Advanced Test Reactor (ATR) during May 1999. The ITV is capable of providing neutron spectral tailoring and individual temperature control for up to 15 experiment capsules simultaneously. The test vehicle consists of three permanently installed in-pile tubes running the length of the reactor vessel. The bores of these in-pile tubes are kept dry and test trains with integral instrumentation are inserted and removed through a transfer shield plate above the reactor vessel head. The test vehicle is designed to irradiate specimens as large as 2.2 cm in diameter, at temperatures of 250 - 800C, achieving neutron damage rates as high as 10 displacements per atom per year in Vanadium. The experiment specimen temperature control is fully automated using a Distributed Control System (DCS) to control up to 15 separate blended gas channels for the ITV. The system remains in place as a permanent ATR Experiment support system and has excess capacity to accommodate experiment program growth. The ITV was initially installed with instrumented dummy tests to allow for testing and characterization of the control system.
Date: September 1, 1999
Creator: Palmer, Alma Joseph; Hong, Bonnie Colleen; Ingram, Frederick William & Stites, David John
System: The UNT Digital Library
Multi-Detector Analysis System for Spent Nuclear Fuel Characterization (open access)

Multi-Detector Analysis System for Spent Nuclear Fuel Characterization

The Spent Nuclear Fuel (SNF) Non-Destructive Analysis (NDA) program at INEEL is developing a system to characterize SNF for fissile mass, radiation source term, and fissile isotopic content. The system is based on the integration of the Fission Assay Tomography System (FATS) and the Gamma-Neutron Analysis Technique (GNAT) developed under programs supported by the DOE Office of Non-proliferation and National Security. Both FATS and GNAT were developed as separate systems to provide information on the location of special nuclear material in weapons configuration (FATS role), and to measure isotopic ratios of fissile material to determine if the material was from a weapon (GNAT role). FATS is capable of not only determining the presence and location of fissile material but also the quantity of fissile material present to within 50%. GNAT determines the ratios of the fissile and fissionable material by coincidence methods that allow the two prompt (immediately) produced fission fragments to be identified. Therefore, from the combination of FATS and GNAT, MDAS is able to measure the fissile material, radiation source term, and fissile isotopics content.
Date: September 1, 1999
Creator: Reber, Edward Lawrence; Aryaeinejad, Rahmat; Cole, Jerald Donald; Drigert, Mark William; Jewell, James Keith; Egger, Ann Elizabeth et al.
System: The UNT Digital Library
A Simplified Shuttle Irradiation Facility for ATR (open access)

A Simplified Shuttle Irradiation Facility for ATR

During the past fifteen years there has been a steady increase in the demand for radioisotopes in nuclear medicine and a corresponding decline in the number of reactors within the U.S. capable of producing them. The Advanced Test Reactor (ATR) is the largest operating test reactor in the U.S., but its isotope production capabilities have been limited by the lack of an installed isotope shuttle irradiation system. A concept for a simple “low cost” shuttle irradiation facility for ATR has been developed. Costs were reduced (in comparison to previous ATR designs) by using a shielded trough of water installed in an occupiable cubicle as a shielding and contamination control barrier for the send and receive station. This shielding concept also allows all control valves to be operated by hand and thus the need for an automatic control system was eliminated. It was determined that 4 – 5 ft of water would be adequate to shield the isotopes of interest while shuttles are transferred to a small carrier. An additional feature of the current design is a non-isolatable by-pass line, which provides a minimum coolant flow to the test region regardless of which control valves are opened or closed. This by-pass …
Date: September 1, 1999
Creator: Palmer, Alma Joseph & Laflin, S. T.
System: The UNT Digital Library
The algebras of large N matrix mechanics (open access)

The algebras of large N matrix mechanics

Extending early work, we formulate the large N matrix mechanics of general bosonic, fermionic and supersymmetric matrix models, including Matrix theory: The Hamiltonian framework of large N matrix mechanics provides a natural setting in which to study the algebras of the large N limit, including (reduced) Lie algebras, (reduced) supersymmetry algebras and free algebras. We find in particular a broad array of new free algebras which we call symmetric Cuntz algebras, interacting symmetric Cuntz algebras, symmetric Bose/Fermi/Cuntz algebras and symmetric Cuntz superalgebras, and we discuss the role of these algebras in solving the large N theory. Most important, the interacting Cuntz algebras are associated to a set of new (hidden!) local quantities which are generically conserved only at large N. A number of other new large N phenomena are also observed, including the intrinsic nonlocality of the (reduced) trace class operators of the theory and a closely related large N field identification phenomenon which is associated to another set (this time nonlocal) of new conserved quantities at large N.
Date: September 16, 1999
Creator: Halpern, M.B. & Schwartz, C.
System: The UNT Digital Library
Status Report on Studies of Recovery Boiler Composite Floor Tube Cracking (open access)

Status Report on Studies of Recovery Boiler Composite Floor Tube Cracking

Cracking of the stainless steel layer of co-extruded 304L stainless steel/SA210 Gd A 1 carbon steel black liquor recovery boiler floor tubes has been identified as one of the most serious material problems in the pulp and paper industry. A DOE-funded study was initiated in 1995 with the goal of determining the cause of and possible solutions to this cracking problem. These studies have characterized tube cracking as well as the chemical and thermal environment and stress state of floor tubes. Investigations of possible cracking mechanisms indicate that stress corrosion cracking rather than thermal fatigue is a more likely cause of crack initiation. The cracking mechanism appears to require the presence of hydrated sodium sulfide and is most likely active during shut-downs and/or start-ups. Based on these results and operating experience, certain alloys appear to be more resistant than others to cracking in the floor environment, and certain operating practices appear to significantly lessen the likelihood of cracking. This report is the latest in a series of progress reports presented on this project.
Date: September 12, 1999
Creator: Eng, P.; Frederick, L. A.; Hoffmann, C. M.; Keiser, J. R.; Mahmood, J.; Maziasz, P. J. et al.
System: The UNT Digital Library
Direct Observation of Phase Transformations in Austenitic Stainless Steel Welds Using In-situ Spatially Resolved and Time-resolved X-ray Diffraction (open access)

Direct Observation of Phase Transformations in Austenitic Stainless Steel Welds Using In-situ Spatially Resolved and Time-resolved X-ray Diffraction

Spatially resolved x-ray diffraction (SRXRD) and time resolved x-ray diffraction (TRXRD) were used to investigate real time solid state phase transformations and solidification in AISI type 304 stainless steel gas tungsten arc (GTA) welds. These experiments were conducted at Stanford Synchrotron Radiation Laboratory (SSRL) using a high flux beam line. Spatially resolved observations of {gamma} {leftrightarrow} {delta} solid state phase transformations were performed in the heat affected zone (HAZ) of moving welds and time-resolved observations of the solidification sequence were performed in the fusion zone (FZ) of stationary welds after the arc had been terminated. Results of the moving weld experiments showed that the kinetics of the {gamma}{yields}{delta} phase transformation on heating in the HAZ were sufficiently rapid to transform a narrow region surrounding the liquid weld pool to the {delta} ferrite phase. Results of the stationary weld experiments showed, for the first time, that solidification can occur directly to the {delta} ferrite phase, which persisted as a single phase for 0.5s. Upon solidification to {delta}, the {delta} {yields} {gamma} phase transformation followed and completed in 0.2s as the weld cooled further to room temperature.
Date: September 23, 1999
Creator: Elmer, J.; Wong, J. & Ressler, T.
System: The UNT Digital Library
Optical Constants of Beryllium from Photoabsorption Measurements for X-Ray Optics Applications (open access)

Optical Constants of Beryllium from Photoabsorption Measurements for X-Ray Optics Applications

Beryllium (Be) has been recently receiving considerable attention as the key material for a range of potential applications in the extreme ultraviolet (EUV) and x-ray region. Most notably, it has been successfully implemented as the spacer material in beryllium-based multilayer mirrors for EUV lithography, achieving experimental reflectivities of about 70% at wavelengths around 11.4 nm. Knowledge of the absorptive and dispersive properties of this material thus becomes important for the modeling of these optics. Experimental photoabsorption results in the region 40-250 eV, derived from transmission measurements on free-standing beryllium foils, are presented in this work. The measured absorption in the region extending a few tens eV below the K edge (111.7 eV) appears to be significantly (up to 50%) lower than the tabulated values. Fine structure above the K edge is also demonstrated in the measurements. These data are incorporated in an updated set for the atomic scattering factors of beryllium, obtained in the range 0.1-30,000 eV. Finally, the Bragg reflectivity of MO/Be multilayer optics is modeled using the new experimental results.
Date: September 30, 1999
Creator: Soufli, R.; Bajt, S. & Gullikson, E.M.
System: The UNT Digital Library
Miscellaneous electricity use in U.S. homes (open access)

Miscellaneous electricity use in U.S. homes

Historically, residential energy and carbon saving efforts have targeted conventional end uses such as water heating, lighting and refrigeration. The emergence of new household appliances has transformed energy use from a few large and easily identifiable end uses into a broad array of ''miscellaneous'' energy services. This group of so called miscellaneous appliances has been a major contributor to growth in electricity demand in the past two decades. We use industry shipment data, lifetimes, and wattage and usage estimates of over 90 individual products to construct a bottom-up end use model (1976-2010). The model is then used to analyze historical and forecasted growth trends, and to identify the largest individual products within the miscellaneous end use. We also use the end use model to identify and analyze policy priorities. Our forecast projects that over the period 1996 to 2010, miscellaneous consumption will increase 115 TWh, accounting for over 90 percent of future residential electricity growth. A large portion of this growth will be due to halogen torchiere lamps and consumer electronics, making these two components of miscellaneous electricity a particularly fertile area for efficiency programs. Approximately 20 percent (40 TWh) of residential miscellaneous electricity is ''leaking electricity'' or energy consumed …
Date: September 30, 1999
Creator: Sanchez, Marla C.; Koomey, Jonathan G.; Moezzi, Mithra M.; Meier, Alan & Huber, Wolfgang
System: The UNT Digital Library
Application of RF Power to Plasma Flow Drive in Fusion Confinement (open access)

Application of RF Power to Plasma Flow Drive in Fusion Confinement

Wave induced flows can produce radially sheared velocity profiles that can in turn stabilize drift wave turbulence and improve plasma confinement. A second-order kinetic theory is developed in one-dimensional slab geometry to treat radio frequency (RF)-driven plasma flows. The Vlasov equation is solved to second order in the RF electric field. Moments of the second-order distribution function give time-averaged expressions for the heating rate, the wave kinetic flux, and the RF force exerted on the plasma. On the collisional or transport time scale, the RF force in the poloidal direction is balanced by neoclassical viscosity, and the force in the radial direction is balanced direction by ambipolar electric fields. Comparison is made with previous theories which have relied on incompressible fluid approximations. Very substantial differences are seen in situations involving the Ion Bernstein Wave, a compressional wave.
Date: September 13, 1999
Creator: Batchelor, D. B.; Berry, L. A.; Carter, M. D. & Jaeger, E. F.
System: The UNT Digital Library
Investigation of Realistic Performance Limits for Tera-Scale Computations (open access)

Investigation of Realistic Performance Limits for Tera-Scale Computations

The two key factors affecting the performance of tera-scale computations are the parallel efficiency of the underlying algorithms, and the local performance on a single processor. In the past, most attention was given to parallel efficiency and parallel scalability. This led to algorithms and techniques that provide good scalability and parallel efficiency. However, it was often assumed that local computations, which require no inter-processor communications, could be performed at a high single processor performance rate (i.e. a high fraction of the advertised peak floating point arithmetic performance). For today's parallel computers, this might not be achievable. An investigation of realistic performance limits on a single processor is the focus of this paper.
Date: September 9, 1999
Creator: Brummer, T.A. & Hanebutte, U.R
System: The UNT Digital Library
Test of a Model Superconducting Magnet for the Hera Ep Interaction Regions. (open access)

Test of a Model Superconducting Magnet for the Hera Ep Interaction Regions.

For the HERA luminosity upgrade two types of compact multifunction superconducting magnets, denoted GO and GG, are needed for installation inside the existing ZEUS and Hl experimental detectors in the year 2000. These magnets contain multiple concentric coil layers organized into independently powered quadrupole, dipole, skew quadrupole and skew dipole coil windings. Production of the first of three GO magnets using a newly constructed coil winding machine is currently in progress at BNL. The GG design is being completed and parallel production at BNL of three GG units will start soon. In this paper we highlight HERA upgrade magnet design challenges, present our production solutions and relate experience and results gained from warm and cold testing of short model magnets.
Date: September 26, 1999
Creator: Parker, B.; Anerella, M.; Escallier, J.; Ghosh, A.; Jain, A.; Marone, A. et al.
System: The UNT Digital Library