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Using the DOE Knowledge Base for Special Event Analysis

Description: The DOE Knowledge Base is a library of detailed information whose purpose is to support the United States National Data Center (USNDC) in its mission to monitor compliance with the Comprehensive Test Ban Treaty (CTBT). One of the important tasks which the USNDC must accomplish is to periodically perform detailed analysis of events of high interest, so-called "Special Events", to provide the national authority with information needed to make policy decisions. In this paper we investigate some possible uses of the Knowledge Base for Special Event Analysis (SEA), and make recommendations for improving Knowledge Base support for SEA. To analyze an event in detail, there are two basic types of data which must be used sensor-derived data (wave- forms, arrivals, events, etc.) and regiohalized contextual data (known sources, geological characteristics, etc.). Cur- rently there is no single package which can provide full access to both types of data, so for our study we use a separate package for each MatSeis, the Sandia Labs-developed MATLAB-based seismic analysis package, for wave- form data analysis, and ArcView, an ESRI product, for contextual data analysis. Both packages are well-suited to pro- totyping because they provide a rich set of currently available functionality and yet are also flexible and easily extensible, . Using these tools and Phase I Knowledge Base data sets, we show how the Knowledge Base can improve both the speed and the quality of SEA. Empirically-derived interpolated correction information can be accessed to improve both location estimates and associated error estimates. This information can in turn be used to identi~ any known nearby sources (e.g. mines, volcanos), which may then trigger specialized processing of the sensor data. Based on the location estimate, preferred magnitude formulas and discriminants can be retrieved, and any known blockages can be identified to prevent miscalculations. Relevant historic ...
Date: October 20, 1998
Creator: Armstrong, H.M.; Harris, J.M. & Young, C.J.
Partner: UNT Libraries Government Documents Department

On the geometry of two-dimensional slices of irregular level sets in turbulent flows

Description: Isoscalar surfaces in turbulent flows are found to be more complex than (self-similar) fractals, in both the far field of liquid-phase turbulent jets and in a realization of Rayleigh-Taylor-instability flow. In particular, they exhibit a scale-dependent coverage dimension, D{sub 2}((lambda)), for 2-D slices of scalar level sets, that increases with scale, from unity, at small scales, to 2, at large scales. For the jet flow and Reynolds numbers investigated, the isoscalar-surface geometry is both scalar-threshold- and Re-dependent; the level-set (coverage) length decreases with increasing Re, indicating enhanced mixing with increasing Reynolds number; and the size distribution of closed regions is well described by lognormal statistics at small scales. A similar D{sub 2}((lambda)) behavior is found for level-set data of 3-D density-interface behavior in recent direct numerical-simulation studies of Rayleigh-Taylor-instability flow. A comparison of (spatial) spectral and isoscalar coverage statistics will be disc
Date: March 20, 1998
Creator: Catrakis, H.J.; Cook, A.W.; Dimotakis, P.E. & Patton, J.M.
Partner: UNT Libraries Government Documents Department

Development of an expert system for transportation of hazardous and radioactive materials

Description: Under the sponsorship of the US Department of Energy`s (DOE`s) Transportation Management Division (EM-261), the Transportation Technologies Group at Oak Ridge National Laboratory (ORNL) has designed and developed an expert system prototype application of the hazardous materials transportation regulations. The objective of this task was to provide a proof-of-concept for developing a computerized expert system that will ensure straightforward, consistent, and error-free application of the hazardous materials transportation regulations. The expert system prototype entailed the analysis of what an expert in hazardous materials shipping information could/should do. From the analysis of the different features required for the expert system prototype, it was concluded that the developmental efforts should be directed to a Windows{trademark} 3.1 hypermedia environment. Hypermedia technology usually works as an interactive software system that gives personal computer users the ability to organize, manage, and present information in a number of formats--text, graphics, sound, and full-motion video.
Date: May 20, 1994
Creator: Ferrada, J.J.; Michelhaugh, R.D. & Rawl, R.R.
Partner: UNT Libraries Government Documents Department

Modeling of current profile evolution and equilibria in negative central shear discharges in the DIII-D experiment

Description: Recent DIII-D advanced tokamak experiments with negative central shear (NCS) have resulted in operation at high normalized {beta}, {beta}{sub N}={beta}/(I/aB), to 4.2, confinement enhancement factors to H=4 (H={tau}{sub E}/{tau}ITER-89P), and record neutron rates for DIII-D to 2.4X10{sup 16} neutrons/sec. These data were obtained during high triangularity, single and double null diverted operation with peaked (L-mode) and broad (H-mode) pressure profiles. We are modeling the spatial and temporal current profile evolution for these discharges using Corsica, a predictive 1-1/2 D equilibrium and transport code. Current profile evolution is self-consistently determined by including current diffusion resulting from current drive due to early neutral beam injection during the ohmic current ramp-up phase of the discharge and the bootstrap current drive associated with pressure profile evolution.
Date: June 20, 1996
Creator: Casper, T.A.; Crotinger, J.; Meyer, W.; Moller, J.; Pearlstein, L.D.; Rice, B. et al.
Partner: UNT Libraries Government Documents Department

Iron Aluminide Composites

Description: Iron aluminides with the B2 structure are highly oxidation and corrosion resistant. They are thermodynamically compatible with a wide range of ceramics such as TiC, WC, TiB{sub 2}, and ZrB{sub 2}. In addition, liquid iron aluminides wet these ceramics very well. Therefore, FeAl/ceramic composites may be produced by techniques such as liquid phase sintering of powder mixtures, or pressureless melt infiltration of ceramic powders with liquid FeAl. These techniques, the resulting microstructure, and their advantages as well as limitations are described. Iron aluminide composites can be very strong. Room temperature flexure strengths as high as 1.8 GPa have been observed for FeAl/WC. Substantial gains in strength at elevated temperatures (1073 K) have also been demonstrated. Above 40 vol.% WC the room temperature flexure strength becomes flaw-limited. This is thought to be due to processing flaws and limited interfacial strength. The fracture toughness of FeAl/WC is unexpectedly high and follows a mile of mixtures. Interestingly, sufficiently thin (< 1 {micro}m) FeAl ligaments between adjacent WC particles fracture not by cleavage, but in a ductile manner. For these thin ligaments the dislocation pile-ups formed during deformation are not long enough to nucleate cleavage fracture, and their fracture mode is therefore ductile. For several reasons, this brittle-to-ductile size transition does not improve the fracture toughness of the composites significantly. However, since no cleavage cracks are nucleated in sufficiently thin FeAl ligaments, slow crack growth due to ambient water vapor does not occur. Therefore, as compared to monolithic iron aluminizes, environmental embrittlement is dramatically reduced in iron aluminide composites.
Date: November 20, 1998
Creator: Schneibel, J.H.
Partner: UNT Libraries Government Documents Department

Enhanced heat transfer using wire-coil inserts for high-heat-load applications.

Description: Enhanced heat-transfer techniques, used to significantly reduce temperatures and thermally induced stresses on beam-strike surfaces, are routinely used at the APS in all critical high-heat-load components. A new heat-transfer enhancement technique being evaluated at the APS involving the use of wire-coil inserts proves to be superior to previously employed techniques. Wire coils, similar in appearance to a common spring, are fabricated from solid wire to precise tolerances to mechanically fit inside standard 0.375-in-diameter cooling channels. In this study, a matrix of wire coils, fabricated with a series of different pitches from several different wire diameters, has been tested for heat-transfer performance and resulting pressure loss. This paper reviews the experimental data and the analytical calculations, compares the data with existing correlations, and interprets the results for APS front-end high-heat-load components.
Date: September 20, 2002
Creator: Collins, J. T.; Conley, C. M.; Attig, J. N. & Baehl, M. M.
Partner: UNT Libraries Government Documents Department

Deployment Options for A Spent Fuel Treatment Facility in the United States

Description: A promising alternative to direct disposal is to process the commercial spent nuclear fuel into key partitions permitting recovery of some of the energy value while providing vital flexibility to the operation of a repository in a manner to minimize and possibly defer the near-term need for future repositories. It is assumed that such a Spent Fuel Treatment Facility (SFTF) will provide significant benefit to the US nuclear waste program and this paper focuses on key options for deployment of such a facility. The SFTF would partition the spent fuel into manageable components that could be recovered, recycled, or dispositioned as economically beneficial to the overall fuel cycle and/or enhances the repository performance. The goal of the SFTF is to reduce the high level waste volume going to a repository, provide for more effective heat management, enhance the containment performance of the specific waste forms, and provide for energy recovery or transmutation as practical.
Date: November 20, 2003
Creator: McGuire, DH.
Partner: UNT Libraries Government Documents Department

Hydrogen Peroxide Storage in Small Sealed Tanks

Description: Unstabilized hydrogen peroxide of 85% concentration has been prepared in laboratory quantities for testing material compatibility and long term storage on a small scale. Vessels made of candidate tank and liner materials ranged in volume from 1 cc to 2540 cc. Numerous metals and plastics were tried at the smallest scales, while promising ones were used to fabricate larger vessels and liners. An aluminum alloy (6061-T6) performed poorly, including increasing homogeneous decay due to alloying elements entering solution. The decay rate in this high strength aluminum was greatly reduced by anodizing. Better results were obtained with polymers, particularly polyvinylidene fluoride. Data reported herein include ullage pressures as a function of time with changing decay rates, and contamination analysis results.
Date: October 20, 1999
Creator: Whitehead, J.
Partner: UNT Libraries Government Documents Department

Klystron 'efficiency loop' for the ALS storage ring RF system

Description: The recent energy crisis in California has led us to investigate the high power RF systems at the Advanced Light Source (ALS) in order to decrease the energy consumption and power costs. We found the Storage Ring Klystron Power Amplifier system operating as designed but with significant power waste. A simple proportional-integrator (PI) analog loop, which controls the klystron collector beam current, as a function of the output RF power, has been designed and installed. The design considerations, besides efficiency improvement, were to interface to the existing system without major expense. They were to also avoid the klystron cathode power supply filter's resonance in the loop's dynamics, and prevent a conflict with the existing Cavity RF Amplitude Loop dynamics. This efficiency loop will allow us to save up to 700 MW-hours of electrical energy per year and increase the lifetime of the klystron.
Date: May 20, 2002
Creator: Kwiatkowski, Slawomir; Julian, Jim & Baptiste, Kenneth
Partner: UNT Libraries Government Documents Department

An Evaluation of Power Law Breakdown in Metals, Alloys, Dispersion Hardened Materials and Compounds

Description: Creep at high stresses often produces strain rates that exceed those that would be predicted by a power law relationship. In this paper, we examine available high stress creep data for pure metals, solid solution alloys, dispersion strengthened powder metallurgy materials and compounds for power law breakdown (PLB). The results show that, if PLB is observed, then the onset of PLB is generally observed at about {epsilon}/D{sub eff} = 10{sup 13} m{sup -2}, where D{sub eff} is the effective diffusion coefficient incorporating lattice and dislocation pipe diffusion. The common origins of PLB for the various systems studied can be found in the production of excess vacancies by plastic deformation. Anomalous behavior in two pure metals (nickel and tungsten) and a solid solution alloy (Fe-25Cr and Fe-26Cr-1Mo) has been analyzed and provides insight into this excess vacancy mechanism. In metal systems, the onset of PLB is related to a change in the nature of the subgrain structure developed. In the PLB region, subgrains become imperfect containing dislocation tangles adjacent to the sub-boundary, and dislocation cells are evident. The dislocation tangles and cells are the source of excess vacancies and increase the creep rate above that predicted from power law creep. If subgrains do not form then PLB is not observed. In solid solution alloys, in which the dominant deformation resistance results from the interaction of solute atoms with moving dislocations, excess vacancies influence the diffusion of these solute atoms. PLB is not observed in many systems. This is attributed either to the presence of a high equilibrium vacancy concentration (because of a low activation energy for vacancy formation) or to the inability to form subgrains.
Date: October 20, 1999
Creator: Lesuer, D.R.; Syn, C.K. & Sherby, O.D.
Partner: UNT Libraries Government Documents Department

Report of the Snowmass M6 Working Group on high intensity proton sources

Description: The U.S. high-energy physics program needs an intense proton source, a 1-4 MW Proton Driver (PD), by the end of this decade. This machine will serve as a stand-alone facility that will provide neutrino superbeams and other high intensity secondary beams such as kaons, muons, neutrons, and anti-protons (cf. E1 and E5 group reports) and also serve as the first stage of a neutrino factory (cf. M1 group report). It can also be a high brightness source for a VLHC. Based on present accelerator technology and project construction experience, it is both feasible and cost-effective to construct a 1-4 MW Proton Driver. Two recent PD design studies have been made, one at FNAL and the other at the BNL. Both designed PD's for 1 MW proton beams at a cost of about U.S. $200M (excluding contingency and overhead) and both designs were upgradeable to 4 MW. An international collaboration between FNAL, BNL and KEK on high intensity proton facilities is addressing a number of key design issues. The superconducting (sc) RF cavities, cryogenics, and RF controls developed for the SNS can be directly adopted to save R&D efforts, cost, and schedule. PD studies are also actively being pursued at Europe and Japan.
Date: August 20, 2002
Creator: Wei, Weiren Chou and J.
Partner: UNT Libraries Government Documents Department

Material Failure and the Growth of Instabilities in Hollow Cylindrical Samples of Aluminum Shocked to 14Gpa and 50Gpa (U)

Description: Understanding the surface stability of metals undergoing dynamic fracture at shock breakout is important to several applications in metals processing. The advantages of using the Pegasus II facility to investigate the phenomena occurring at shock break out are described. As an example of the data collected, we concentrate on brief descriptions of two experiments that compared the tensile failure, i.e. ''spall'', patterns in the presence of sinusoidal perturbations seeded on the free inner surface of cylindrical samples made of structural grade Al 6061.T6. These samples were subjected to ramped waves with shock pressures of 14 GPa and 50 GPa to observe the effect of pressure on the production of a type of volumetric failure that is mentioned here ''microspall.'' This failed region behind the exiting surface of the shock wave is comprised of a significant volume of low-density, probably granular, material. The failure mechanism, combined with the forces that cause inertial instability, leads to rapid pattern growth in the failed material, observable as density variations, as well as to pattern growth on the surface. Pattern growth was observed to vary with perturbation amplitude, wavelength, and shock pressure. Both increased pressure and increased amplitude were shown to destabilize a stable perturbation. Increasing the wavelength by a factor of 3 was shown to result in significantly slower growth of the pattern within the failed volume. The mechanisms leading to the formation of the spall volume and to the patterns are discussed briefly.
Date: November 20, 1999
Creator: Stokes, J.; Fulton, R.D.; Morgan, D.V.; Obst, A.W.; Oro, D.M.; Oona, H. et al.
Partner: UNT Libraries Government Documents Department

High pT hadrons in Au+Au collisions at RHIC

Description: High pT hadrons produced in ultra-relativistic heavy-ion collisions at RHIC probe nuclear matter at extreme conditions of high energy density. Experimental measurements in Au+Au collisions at sqrt sNN=130, 200 GeV establish the existence of strong medium effects on hadron production well into the perturbative regime.
Date: December 20, 2002
Creator: Filimonov, K.
Partner: UNT Libraries Government Documents Department

A theoretical analysis of the CH{sub 3} + H reaction : isotope effects, the high pressure limit, and transition state recrossing.

Description: The reaction of methyl radicals with hydrogen atoms is studied with a combination of ab initio quantum chemistry, variational transition state theory, and classical trajectory simulations. The interaction between the two radicals, including the umbrella mode of the methyl radical, is examined at the CAS+1+2 level using an augmented correlation consistent polarized valence triple zeta basis set. The implementation of an analytic representation of the ab initio data within variable reaction coordinate transition state theory yields predictions for the zero-pressure limit isotopic exchange rate constants that are about 15% greater than the available experimental data. Trajectory simulations indicate that the transition state recrossing factor for the capture process is 0.90, essentially independent of temperature and isotope. The dynamically corrected theoretical prediction for the CH{sub 3} + H high pressure rate coefficient is well reproduced by the expression 1.32 x 10{sup -10}T{sup 0.153}exp(-15.1/RT) cm{sup 3}molecule{sup -1}s{sup -1}, where R = 1.987 cal mole{sup -1} K{sup -1}, for temperatures between 200 and 2400 K. This prediction is in good agreement with the converted experimental data for all but the one measurement at 200 K. Calculations for the triplet abstraction channel suggest that it is unimportant. Methyl umbrella mode variations have surprisingly little effect on the predicted rate coefficients.
Date: December 20, 2001
Creator: Klippenstein, S. J.; Georgievskii, Y. & Harding, L.
Partner: UNT Libraries Government Documents Department

The distant type Ia supernova rate

Description: We present a measurement of the rate of distant Type Ia supernovae derived using 4 large subsets of data from the Supernova Cosmology Project. Within this fiducial sample,which surveyed about 12 square degrees, thirty-eight supernovae were detected at redshifts 0.25--0.85. In a spatially flat cosmological model consistent with the results obtained by the Supernova Cosmology Project, we derive a rest-frame Type Ia supernova rate at a mean red shift z {approx_equal} 0.55 of 1.53 {sub -0.25}{sub -0.31}{sup 0.28}{sup 0.32} x 10{sup -4} h{sup 3} Mpc{sup -3} yr{sup -1} or 0.58{sub -0.09}{sub -0.09}{sup +0.10}{sup +0.10} h{sup 2} SNu(1 SNu = 1 supernova per century per 10{sup 10} L{sub B}sun), where the first uncertainty is statistical and the second includes systematic effects. The dependence of the rate on the assumed cosmological parameters is studied and the redshift dependence of the rate per unit comoving volume is contrasted with local estimates in the context of possible cosmic star formation histories and progenitor models.
Date: May 20, 2002
Creator: Pain, R.; Fabbro, S.; Sullivan, M.; Ellis, R.S.; Aldering, G.; Astier, P. et al.
Partner: UNT Libraries Government Documents Department

Failure of Vapor Overheads Discharge Line for a Radioactive Waste Evaporator

Description: A 2-inch schedule 40 steel core pipe in an evaporator overheads discharge line broke at several locations downstream from a section of the line where it bridges a road. Fish mouth openings that developed along the pipe seams were initiated at lack of fusion defects in the pipe welds. A vacuum created in the piping upstream of the breaks prevented full drainage of the water upon shut down of the pump. Freezing of water in the pipe (the line was not heat traced) and water hammer effects occurring with pump restart could each contribute to the extensive deformation and tearing observed at the breaks. Both the weld flaws and the over pressure contributed to the outcome. All pipe was replaced and a vacuum break was installed to eliminate the problem.
Date: January 20, 2004
Creator: Jenkins, C.F.
Partner: UNT Libraries Government Documents Department

COLDMASS FOR LHC DIPOLE INSERTION MAGNETS.

Description: Brookhaven National Laboratory (BNL) is building a number of magnets for the insertion regions of the Large Hadron Collider (LHC). This paper presents the magnetic design and the expected field quality in 2-in-1 dipole magnets. A unique feature of this coldmass design is the use of an oblate-shaped yoke. This concept permits a variety of BNL-built magnets to have a similar overall design and allows the LHC main dipole cryostat, post, etc., to be used in these magnets. The proposed oblate-shaped yoke also offers a way to reduce the overall cryostat size in future magnets. The dipoles will use the same 80 mm aperture coils as used in the Relativistic Heavy Ion Collider (RHIC) dipole magnets, but will use stainless steel collars. The design presented here is still evolving and the magnets may be built differently than described here.
Date: October 20, 1997
Creator: GUPTA,R.; ALFORQUE,R.; ANERELLA,M.; KELLY,E.; PLATE,S.; RUFER,C. et al.
Partner: UNT Libraries Government Documents Department

Mitigation of the electron-cloud effect in the PSR and SNS proton storage rings by tailoring the bunch profile

Description: For the storage ring of the Spallation Neutron Source(SNS) at Oak Ridge, and for the Proton Storage Ring (PSR) at Los Alamos, both with intense and very long bunches, the electroncloud develops primarily by the mechanism of trailing-edge multipacting. We show, by means of simulations for the PSR, how the resonant nature of this mechanism may be effectively broken by tailoring the longitudinal bunch profile at fixed bunch charge, resulting in a significant decrease in the electron-cloud effect. We briefly discuss the experimental difficulties expected in the implementation of this cure.
Date: May 20, 2003
Creator: Pivi, M. & Furman, M.A.
Partner: UNT Libraries Government Documents Department

Design features of high-intensity medium-energy superconducting heavy-ion Linac.

Description: The proposed Rare Isotope Accelerator (RIA) requires the construction of a cw 1.4 GV superconducting (SC) linac that is capable of producing 400 kW beams of all ions from protons at 900 MeV to uranium at 400 MeV/u. The design of such a linac was outlined at the previous Linac conference. This linac will accelerate multiple-charge-states (multi-q) of the heaviest ion beams, for which the beam current is limited by ion-source performance. The linac consists of two different types of accelerating and focusing lattice: for uranium below {approx}85 MeV/u the focusing is provided by SC solenoids installed in cryostats with the SC resonators while in the high-beta section the focusing elements are located outside of the cryostats. A detailed design has been developed for the focusing-accelerating lattice of the linac. Beam dynamics studies have been performed with the goal of optimization of the linac structure in order to reduce a possible effective emittance growth of the multi-q uranium beam. A wide tuning range of the accelerating and focusing fields is required for acceleration of the variety of ions with different charge-to-mass ratios to the highest possible energy in single charge state mode. The focusing must be retuned for different ion masses to avoid resonance coupling between the transverse and longitudinal motions. Any visible impact of this coupling on the formation of beam halo must be avoided due to the high beam power.
Date: September 20, 2002
Creator: Ostroumov, P. N.
Partner: UNT Libraries Government Documents Department

Simulating Intense Ion Beams for Inertial Fusion Energy

Description: The Heavy Ion Fusion (HIF) program's goal is the development of the body of knowledge needed for Inertial Fusion Energy (IFE) to realize its promise. The intense ion beams that will drive HIF targets are rzonneutral plasmas and exhibit collective, nonlinear dynamics which must be understood using the kinetic models of plasma physics. This beam physics is both rich and subtle: a wide range in spatial and temporal scales is involved, and effects associated with both instabilities and non-ideal processes must be understood. Ion beams have a ''long memory,'' and initialization of a beam at mid-system with an idealized particle distribution introduces uncertainties; thus, it will be crucial to develop, and to extensively use, an integrated and detailed ''source-to-target'' HIF beam simulation capability. We begin with an overview of major issues.
Date: February 20, 2001
Creator: Friedman, A.
Partner: UNT Libraries Government Documents Department

Nanofluid technology : current status and future research.

Description: Downscaling or miniaturization has been a recent major trend in modern science and technology. Engineers now fabricate microscale devices such as microchannel heat exchangers, and micropumps that are the size of dust specks. Further major advances would be obtained if the coolant flowing in the microchannels were to contain nanoscale particles to enhance heat transfer. Nanofluid technology will thus be an emerging and exciting technology of the 21st century. This paper gives a brief history of the Advanced Fluids Program at Argonne National Laboratory (ANL), discusses the concept of nanofluids, and provides an overview of the R and D program at ANL on the production, property characterization, and performance of nanofluids. It also describes examples of potential applications and benefits of nanofluids. Finally, future research on the fundamentals and applications of nanofluids is addressed.
Date: October 20, 1998
Creator: Choi, S. U.-S.
Partner: UNT Libraries Government Documents Department