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Short Term Climatological Wind Data as a Tool for Wind Forecasting

Description: Utilizing short-term climatological wind data can enhance wind speed and wind direction forecasts. An analysis of regional or tower-based wind rose summaries can be useful forecast guides especially when synoptic-scale pressure gradients are weak. Predictive data from multiple models can be plotted against short-term climatological wind data to assess deviations from expected norms and differences between forecast models. Site-specific comparisons between predicted data and observed climatological distributions can provide further insights to the forecaster. These methods can be applied to any location where sufficient climatological data (at least two years) is available.
Date: January 28, 2004
Creator: Parker, MJ
Partner: UNT Libraries Government Documents Department

Measurement of the radiation field surrounding the Collider Detector at Fermilab

Description: We present here the first direct and detailed measurements of the spatial distribution of the ionizing radiation surrounding a hadron collider experiment. Using data from two different exposures we measure the effect of additional shielding on the radiation field around the Collider Detector at Fermilab (CDF). Employing a simple model we parameterize the ionizing radiation field surrounding the detector.
Date: January 28, 2004
Creator: al., K. Kordas et
Partner: UNT Libraries Government Documents Department

Barrier rf systems in synchrotrons

Description: Recently, many interesting applications of the barrier RF system in hadron synchrotrons have been realized. A remarkable example of this is the development of longitudinal momentum mining and implementation at the Fermilab Recycler for extraction of low emittance pbars for the Tevatron shots. At Fermilab, we have barrier RF systems in four different rings. In the case of Recycler Ring, all of the rf manipulations are carried out using a barrier RF system. Here, the author reviews various uses of barrier rf systems in particle accelerators including some new schemes for producing intense proton beam and possible new applications.
Date: June 28, 2004
Creator: Bhat, Chandra M.
Partner: UNT Libraries Government Documents Department

Liquid Lithium Limiter Experiments in CDX-U

Description: Recent experiments in the Current Drive Experiment-Upgrade provide a first-ever test of large area liquid lithium surfaces as a tokamak first wall, to gain engineering experience with a liquid metal first wall, and to investigate whether very low recycling plasma regimes can be accessed with lithium walls. The CDX-U is a compact (R = 34 cm, a = 22 cm, B{sub toroidal} = 2 kG, I{sub P} = 100 kA, T{sub e}(0) = 100 eV, n{sub e}(0) {approx} 5 x 10{sup 19} m{sup -3}) spherical torus at the Princeton Plasma Physics Laboratory. A toroidal liquid lithium tray limiter with an area of 2000 cm{sup 2} (half the total plasma limiting surface) has been installed in CDX-U. Tokamak discharges which used the liquid lithium limiter required a fourfold lower loop voltage to sustain the plasma current, and a factor of 5-8 increase in gas fueling to achieve a comparable density, indicating that recycling is strongly reduced. Modeling of the discharges demonstrated that the lithium-limited discharges are consistent with Z{sub effective} < 1.2 (compared to 2.4 for the pre-lithium discharges), a broadened current channel, and a 25% increase in the core electron temperature. Spectroscopic measurements indicate that edge oxygen and carbon radiation are strongly reduced.
Date: October 28, 2004
Creator: Majeski, R.; Jardin, S.; Kaita, R.; Gray, T.; Marfuta, P.; Spaleta, J. et al.
Partner: UNT Libraries Government Documents Department

Oxygen monitoring cells at Fermilab

Description: Questions have been raised about the accuracy of oxygen monitoring for personnel safety around systems containing gases with a molecular weight less than nitrogen. A study has been performed to test the accuracy of the oxygen monitoring devices used at Fermilab. Portable and fixed oxygen monitoring equipment is used throughout Fermilab for personnel safety in defined oxygen deficiency hazard (ODH) areas. The results are presented as well as corrective measures taken to ensure accuracy and maintain the proper level of personnel safety.
Date: July 28, 2004
Creator: Theilacker, Jay C.
Partner: UNT Libraries Government Documents Department

Generation IV Nuclear Energy Systems Construction Cost Reductions Through the Use of Virtual Environments

Description: The objective of this multi-phase project is to demonstrate the feasibility and effectiveness of using full-scale virtual reality simulation in the design, construction, and maintenance of future nuclear power plants. The project will test the suitability of immersive virtual reality technology to aid engineers in the design of the next generation nuclear power plant and to evaluate potential cost reductions that can be realized by optimization of installation and construction sequences. The intent is to see if this type of information technology can be used in capacities similar to those currently filled by full-scale physical mockups. This report presents the results of the completed project.
Date: February 28, 2004
Creator: Shaw, Timothy & Whisker, Vaugh
Partner: UNT Libraries Government Documents Department

Collisional Transport in a Low Aspect Ratio Tokamak -- Beyond the Drift Kinetic Formalism

Description: Calculations of collisional thermal and particle diffusivities in toroidal magnetic plasma confinement devices order the toroidal gyroradius to be small relative to the poloidal gyroradius. This ordering is central to what is usually referred to as neoclassical transport theory. This ordering is incorrect at low aspect ratio, where it can often be the case that the toroidal gyroradius is larger than the poloidal gyroradius. We calculate the correction to the particle and thermal diffusivities at low aspect ratio by comparing the diffusivities as determined by a full orbit code (which we refer to as omni-classical diffusion) with those from a gyroaveraged orbit code (neoclassical diffusion). In typical low aspect ratio devices the omni-classical diffusion can be up to 2.5 times the calculated neoclassical value. We discuss the implications of this work on the analysis of collisional transport in low aspect ratio magnetic confinement experiments.
Date: January 28, 2004
Creator: Gates, D.A. & White, R.B.
Partner: UNT Libraries Government Documents Department

Direct synthesis of LiNi1/3Co1/3Mn1/3O2 from nitrateprecursors

Description: Two novel methods for synthesis of the title compound directly from metal nitrates are described. Phase-pure materials are produced when precursors are calcined between 600 and 1000 C, with little to no ion mixing exhibited for products heated to 900 C or above. The electrochemical characteristics of these materials depended upon calcination temperature and synthesis method, with results comparable to a commercial sample for the materials made at high temperatures in a one-step process without combustion. The sample prepared by combustion also exhibited very stable capacity retention upon cycling.
Date: April 28, 2004
Creator: Patoux, Sebastien & Doeff, Marca M.
Partner: UNT Libraries Government Documents Department

Fast Ion Effects on Fishbones and n=1 Kinks in JET Simulated by a Non-perturbative NOVA-KN Code

Description: New global non-perturbative hybrid code, NOVA-KN, and simulations of resonant type modes in JET [Joint European Torus] plasmas driven by energetic H-minority ions are presented. The NOVA-KN code employs the ideal-MHD description for the background plasma and treats non-perturbatively the fast particle kinetic response, which includes the fast ion finite orbit width (FOW) effect. In particular, the n = 1 fishbone mode, which is in precession drift resonance with fast ions, is studied. The NOVA-KN code is applied to model an n = 1 (f = 50-80kHz) MHD activity observed recently in JET low density plasma discharges with high fast ion (H-minority) energy content generated during the ion cyclotron resonance heating (ICRH). This n = 1 MHD activity is interpreted as the instability of the n = 1 precession drift frequency fishbone modes.
Date: October 28, 2004
Creator: Gorelenkov, N.N.; Cheng, C.Z.; Kiptily, V.G.; Mantsinen, M.J.; Sharapov, S.E. & Contributors, the JET-EFDA
Partner: UNT Libraries Government Documents Department

X-ray photoelectron spectroscopy of negative electrodes from high-power lithium-ion cells showing various levels of power fade

Description: High-power lithium-ion cells for transportation applications are being developed and studied at Argonne National Laboratory. The current generation of cells containing LiNi{sub 0.8}Co{sub 0.15}Al{sub 0.05}O{sub 2}-based cathodes, graphite-based anodes, and LiPF6-based electrolytes show loss of capacity and power during accelerated testing at elevated temperatures. Negative electrode samples harvested from some cells that showed varying degrees of power and capacity fade were examined by X-ray photoelectron spectroscopy (XPS). The samples exhibited a surface film on the graphite, which was thicker on samples from cells that showed higher fade. Furthermore, solvent-based compounds were dominant on samples from low power fade cells, whereas LiPF{sub 6}-based products were dominant on samples from high power fade cells. The effect of sample rinsing and air exposure is discussed. Mechanisms are proposed to explain the formation of compounds suggested by the XPS data.
Date: February 28, 2004
Creator: Herstedt, Marie; Abraham, Daniel P. & Kerr, John B.
Partner: UNT Libraries Government Documents Department

Observations of Anisotropic Ion Temperature in the NSTX Edge during RF Heating

Description: A new spectroscopic diagnostic with both toroidal and poloidal views has been implemented in the edge of the National Spherical Torus Experiment (NSTX). This edge rotation diagnostic (ERD) was designed to measure the velocity and temperature of ions. The intersection of the diagnostic sightlines with the intrinsic emission shell provides the localization of the measurement. There are 7 toroidally directed views and 6 poloidally directed views of the outboard plasma edge. The poloidal view is {approx}20 cm (toroidally) from the RF antenna, and the toroidal view is {approx}2 m away. The sightlines are nearly tangent to the flux surfaces. The C{sup 2+} triplet near 4651 {angstrom} and the He{sup +} line at 4685 {angstrom} are measured. In the results presented here, helium is the bulk, ''working'' ion of the discharge. The NSTX is a large spherical tokamak with a major radius of 0.85 m and a minor radius of 0.65 m. The outer walls and center-stack are lined with protective carbon tiles. Pulse lengths for these NSTX discharges are {approx} 600 ms, with an on-axis toroidal magnetic field of {approx} 0.3 T. The plasma current is 500 kA. The on-axis electron temperature and density are {le} 2 keV and {approx} 2 x 10{sup 19} m{sup -3}, respectively with {le} 4.3 MW of High Harmonic Fast Wave (HHFW) Radio Frequency (RF) auxiliary heating.
Date: June 28, 2004
Creator: Biewer, T.M.; Bell, R.E.; Ryan, P.M. & Wilson, J.R.
Partner: UNT Libraries Government Documents Department

Discharge model for the lithium iron-phosphate electrode

Description: This paper develops a mathematical model for lithium intercalation and phase change in an iron phosphate-based lithium-ion cell in order to understand the cause for the low power capability of the material. The juxtaposition of the two phases is assumed to be in the form of a shrinking core, where a shell of one phase covers a core of the second phase. Diffusion of lithium through the shell and the movement of the phase interface are described and incorporated into a porous electrode model consisting of two different particle sizes. Open-circuit measurements are used to estimate the composition ranges of the single-phase region. Model-experimental comparisons under constant current show that ohmic drops in the matrix phase, contact resistances between the current collector and the porous matrix, and transport limitations in the iron phosphate particle limit the power capability of the cells. Various design options, consisting of decreasing the ohmic drops, using smaller particles, and substituting the liquid electrolyte by a gel are explored, and their relative importance discussed. The model developed in this paper can be used as a means of optimizing the cell design to suit a particular application.
Date: February 28, 2004
Creator: Srinivasan, Venkat & Newman, John
Partner: UNT Libraries Government Documents Department

New waveguide-type HOM damper for ALS storage ring cavities.

Description: The ALS storage ring 500 MHz RF system uses two re-entrant accelerating cavities powered by a single 320kW PHILLIPS YK1305 klystron. During several years of initial operation, the RF cavities were not equipped with effective passive HOM damper systems. Longitudinal beam stability was achieved through cavity temperature control and the longitudinal feedback system (LFB), which was often operating at the edge of its capabilities. As a result, longitudinal beam stability was a significant operations issue at the ALS. During two consecutive shutdown periods (April 2002 and 2003) we installed E-type HOM dampers on the main and third harmonic cavities. These devices dramatically decreased the Q-values of the longitudinal anti-symmetric HOM modes. The next step is to damp the rest of the longitudinal HOM modes in the main cavities below the synchrotron radiation damping level. This will hopefully eliminate the need for the LFB and set the stage for a possible increase in beam current. The ''waveguide'' type of HOM damper was the only option that didn't significantly compromise the vacuum performance of the RF cavity. The design process and the results of the low level measurements of the new waveguide dampers are presented in this paper.
Date: June 28, 2004
Creator: Kwiatkowski, Slawomir; Baptiste, Kenneth & Julian, James
Partner: UNT Libraries Government Documents Department

Report of the APS Neutrino Study Reactor Working Group

Description: The worldwide program to understand neutrino oscillations and determine the neutrino mixing parameters, CP violating effects, and mass hierarchy will require a broad combination of measurements. The group believes that a key element of this future neutrino program is a multi-detector neutrino experiment (with baselines of {approx} 200 m and {approx} 1.5 km) with a sensitivity of sin{sup 2} 2{theta}{sub 13} = 0.01. In addition to oscillation physics, the reactor experiment may provide interesting measurements of sin{sup 2} {theta}{sub W} at Q{sup 2} = 0, neutrino couplings, magnetic moments, and mixing with sterile neutrino states. {theta}{sub 13} is one of the twenty-six parameters of the standard model, the best model of electroweak interactions for energies below 100 GeV and, as such, is worthy of a precision measurement independent of other considerations. A reactor experiment of the proposed sensitivity will allow a measurement of {theta}{sub 13} with no ambiguities and significantly better precision than any other proposed experiment, or will set limits indicating the scale of future experiments required to make progress. Figure 1 shows a comparison of the sensitivity of reactor experiments of different scales with accelerator experiments for setting limits on sin{sup 2} 2{theta}{sub 13} if the mixing angle is very small, or for making a measurement of sin{sup 2} 2{theta}{sub 13} if the angle is observable. A reactor experiment with a 1% precision may also resolve the degeneracy in the {theta}{sub 23} parameter when combined with long-baseline accelerator experiments. In combination with long-baseline measurements, a reactor experiment may give early indications of CP violation and the mass hierarchy. The combination of the T2K and Nova long-baseline experiments will be able to make significant measurements of these effects if sin{sup 2} 2{theta}{sub 13} > 0.05 and with enhanced beam rates can improve their reach to the sin{sup 2} 2{theta}{sub ...
Date: October 28, 2004
Creator: Abouzaid, E.; Anderson, K.; Barenboim, G.; Berger, B.; Blucher, E.; Bolton, T. et al.
Partner: UNT Libraries Government Documents Department

Managing discovery risks--A Tevatron case study

Description: To meet the increasing need for higher performance, Management of Fermi National Accelerator Laboratory has undertaken various projects to improve systems associated with the Tevatron high-energy particle collider located at Batavia, Illinois. One of the larger projects is the Tevatron Beam Position Monitor (BPM) system. The objective of this project is to replace the existing BPM electronics and software system that was originally installed during early 1980s, along with the original construction of the Tevatron.The original system consists of 236 beam position monitors located around the underground tunnel of the accelerator. Above ground control systems are attached to these monitors using pickup cables. When the Tevatron collider is operational, signals received from the BPMs are used to perform a number of control and diagnostic tasks. The original system can only capture the proton signals from the collider. The new system, when fully operational, will be able to capture combined proton and antiproton signals and will be able to separate the antiproton signal from the combined signal at high resolution. This significant enhancement was beyond the range of technical capabilities when the Tevatron was constructed about two decades ago. To take advantage of exceptional progress made in the hardware and software area in past two decades, Department of Energy approved funding of the BPM electronics and software replacement project. The approximate length of the project is sixteen months with a budget of four million dollars not including overhead, escalation, and contingencies. Apart from cost and schedule risks, there are two major risks associated with this research and development project. The primary risk is the risk of discovery. Since the Tevatron beam path is highly complex, BPMs have to acquire and process a large amount of data. In this environment, analysis of data to separate antiproton signals is even more complex. Finding ...
Date: July 28, 2004
Creator: Banerjee, Bakul
Partner: UNT Libraries Government Documents Department

BWR AXIAL PROFILE

Description: The purpose of this calculation is to develop axial profiles for estimating the axial variation in burnup of a boiling water reactor (BWR) assembly spent nuclear fuel (SNF) given the average burnup of an assembly. A discharged fuel assembly typically exhibits higher burnup in the center and lower burnup at the ends of the assembly. Criticality safety analyses taking credit for SNF burnup must account for axially varying burnup relative to calculations based on uniformly distributed assembly average burnup due to the under-burned tips. Thus, accounting for axially varying burnup in criticality analyses is also referred to as accounting for the ''end effect'' reactivity. The magnitude of the reactivity change due to ''end effect'' is dependent on the initial assembly enrichment, the assembly average burnup, and the particular axial profile characterizing the burnup distribution. The set of bounding axial profiles should incorporate multiple BWR core designs and provide statistical confidence (95 percent confidence that 95 percent of the population is bound by the profile) that end nodes are conservatively represented. The profiles should also conserve the overall burnup of the fuel assembly. More background on BWR axial profiles is provided in Attachment I.
Date: September 28, 2004
Creator: Huffer, J.
Partner: UNT Libraries Government Documents Department

Jet Physics at CDF

Description: Jets have been studied by the CDF Collaboration [1] as a means of searching for new particles and interactions, testing a variety of perturbative QCD predictions, and providing input for the global parton distribution function (PDF) fits. Unless otherwise indicated below, the jets were reconstructed using a cone algorithm [2] with cone radius R = 0.7 from data taken at the Fermilab Tevatron collider in Run 2, 2001-2003, with {radical}s = 1.96 TeV. Central jets, in the pseudorapidity range relative to fixed detector coordinates 0.1 < |{eta}| < 0.7, are used.
Date: June 28, 2004
Creator: Seidel, Sally
Partner: UNT Libraries Government Documents Department

Characterization of Solid Oxide Fuel Cell Components Using Electromagnetic Model-Based Sensors

Description: In this Phase I SBIR, the contractor demonstrated a number of capabilities of model-based sensors such as MWM sensors and MWM-Arrays. The key results include (1) porosity/microstructure characterization for anodes, (2) potential for cathode material characterization, (3) stress measurements in nickel and cobalt, and (4) potential for stress measurements in non-magnetic materials with a ferromagnetic layer. In addition, potential applications for manufacturing quality control of nonconductive layers using interdigitated electrode dielectrometers have been identified. The results indicate that JENTEK's MWM technology can be used to significantly reduce solid oxide fuel cell production and operating costs in a number of ways. Preliminary investigations of solid oxide fuel cell health monitoring and scale-up issues to address industry needs have also been performed.
Date: December 28, 2004
Creator: Zilberstein, Vladimir; Craven, Chris & Goldfine, Neil
Partner: UNT Libraries Government Documents Department

Advanced ST Plasma Scenario Simulations for NSTX

Description: Integrated scenario simulations are done for NSTX [National Spherical Torus Experiment] that address four primary milestones for developing advanced ST configurations: high {beta} and high {beta}{sub N} inductive discharges to study all aspects of ST physics in the high-beta regime; non-inductively sustained discharges for flattop times greater than the skin time to study the various current-drive techniques; non-inductively sustained discharges at high {beta} for flattop times much greater than a skin time which provides the integrated advanced ST target for NSTX; and non-solenoidal start-up and plasma current ramp-up. The simulations done here use the Tokamak Simulation Code (TSC) and are based on a discharge 109070. TRANSP analysis of the discharge provided the thermal diffusivities for electrons and ions, the neutral-beam (NB) deposition profile, and other characteristics. CURRAY is used to calculate the High Harmonic Fast Wave (HHFW) heating depositions and current drive. GENRAY/CQL3D is used to establish the heating and CD [current drive] deposition profiles for electron Bernstein waves (EBW). Analysis of the ideal-MHD stability is done with JSOLVER, BALMSC, and PEST2. The simulations indicate that the integrated advanced ST plasma is reachable, obtaining stable plasmas with {beta} {approx} 40% at {beta}{sub N}'s of 7.7-9, I{sub P} = 1.0 MA, and B{sub T} = 0.35 T. The plasma is 100% non-inductive and has a flattop of 4 skin times. The resulting global energy confinement corresponds to a multiplier of H{sub 98(y,2)} = 1.5. The simulations have demonstrated the importance of HHFW heating and CD, EBW off-axis CD, strong plasma shaping, density control, and early heating/H-mode transition for producing and optimizing these plasma configurations.
Date: October 28, 2004
Creator: Kessel, C.E.; Synakowski, E.J.; Gates, D.A.; Harvey, R.W.; Kaye, S.M.; Mau, T.K. et al.
Partner: UNT Libraries Government Documents Department

A Cumulant-based Analysis of Nonlinear Magnetospheric Dynamics

Description: Understanding magnetospheric dynamics and predicting future behavior of the magnetosphere is of great practical interest because it could potentially help to avert catastrophic loss of power and communications. In order to build good predictive models it is necessary to understand the most critical nonlinear dependencies among observed plasma and electromagnetic field variables in the coupled solar wind/magnetosphere system. In this work, we apply a cumulant-based information dynamical measure to characterize the nonlinear dynamics underlying the time evolution of the Dst and Kp geomagnetic indices, given solar wind magnetic field and plasma input. We examine the underlying dynamics of the system, the temporal statistical dependencies, the degree of nonlinearity, and the rate of information loss. We find a significant solar cycle dependence in the underlying dynamics of the system with greater nonlinearity for solar minimum. The cumulant-based approach also has the advantage that it is reliable even in the case of small data sets and therefore it is possible to avoid the assumption of stationarity, which allows for a measure of predictability even when the underlying system dynamics may change character. Evaluations of several leading Kp prediction models indicate that their performances are sub-optimal during active times. We discuss possible improvements of these models based on this nonparametric approach.
Date: January 28, 2004
Creator: Johnson, Jay R. & Wing, Simon
Partner: UNT Libraries Government Documents Department

Beyond the standard model in many directions

Description: These four lectures constitute a gentle introduction to what may lie beyond the standard model of quarks and leptons interacting through SU(3){sub c} {direct_product} SU(2){sub L} {direct_product} U(1){sub Y} gauge bosons, prepared for an audience of graduate students in experimental particle physics. In the first lecture, I introduce a novel graphical representation of the particles and interactions, the double simplex, to elicit questions that motivate our interest in physics beyond the standard model, without recourse to equations and formalism. Lecture 2 is devoted to a short review of the current status of the standard model, especially the electroweak theory, which serves as the point of departure for our explorations. The third lecture is concerned with unified theories of the strong, weak, and electromagnetic interactions. In the fourth lecture, I survey some attempts to extend and complete the electroweak theory, emphasizing some of the promise and challenges of supersymmetry. A short concluding section looks forward.
Date: April 28, 2004
Creator: Quigg, Chris
Partner: UNT Libraries Government Documents Department

Constraints on flow regimes in wide-aperture fractures

Description: In recent years, significant advances have been made in our understanding of the complex flow processes in individual fractures, aided by flow visualization experiments and conceptual modeling efforts. These advances have led to the recognition of several flow regimes in individual fractures subjected to different initial and boundary conditions. Of these, the most important regimes are film flow, rivulet flow, and sliding of droplets. The existence of such significantly dissimilar flow regimes has been a major hindrance in the development of self-consistent conceptual models of flow for single fractures that encompass all the flow regimes. The objective of this study is to delineate the existence of the different flow regimes in individual fractures. For steady-state flow conditions, we developed physical constraints on the different flow regimes that satisfy minimum energy configurations, which enabled us to segregate the wide range of fracture transmissivity (volumetric flow rate per fracture width) into several flow regimes. These are, in increasing order of flow rate, flow of adsorbed films, flow of sliding drops, rivulet flow, stable film flow, and unstable (turbulent) film flow. The scope of this study is limited to wide-aperture fractures with the flow on the opposing sides of fracture being independent.
Date: February 28, 2004
Creator: Ghezzehei, Teamrat A.
Partner: UNT Libraries Government Documents Department