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810 Future plans (open access)

810 Future plans

It is believed that a good bet for finding the Quark-Gluon Plasma at AGS energies is with the heaviest projectiles on the heaviest target, i.e. Au on Au. One of the likely signatures of the plasma is strangeness enhancement. Al Saulys has shown what it's like to find {Delta} and K{degree} with Si projectiles. Our Monte Carlo simulations show track densities 4 times higher for Au projectiles. In addition, the Au beam itself produces 30 times more ionization. Thus the present TPC's will be limited to only a few hundred ions per sec. This paper discusses plans for these experiments and modification to TPC. 9 figs.
Date: March 27, 1990
Creator: Etkin, A.; Foley, K. J.; Hackenburg, R. W.; Longacre, R. S.; Love, W. A.; Morris, T. W. et al.
System: The UNT Digital Library
Abundances and Spectra for Cosmic-Ray Nuclei from Li to Fe For 2to 150 GeV/n (open access)

Abundances and Spectra for Cosmic-Ray Nuclei from Li to Fe For 2to 150 GeV/n

We report measurements of the absolute and relative abundances, differential energy spectra, and spectral indices for cosmic-ray nuclei from Li to Fe for 2 to 150 GeV/nucleon. These measurements were made using a balloon-borne superconducting magnetic spectrometer with scintillators and optical spark chambers. The abundances of Li, Be, and B for rigidities below 10 GV/c are consistent with an energy-independent mean interstellar pathlength of 4 1/2 {+-} 1/2 g cm{sup -2} for all propagation models. The abundances of all elements above 10 GV/c are consistent with an interstellar pathlength decreasing with rigidity as R{sup -n} with an index n = 0.6{sub -0.3}{sup +0.4}. All differential source spectra can be fitted by power laws in total energy per nucleon with the same spectral index, which is between 2.5 and 2.6 depending on n. If n is near 0.5 (as for simple diffusion), the source index is 2.54 {+-} 0.03. Relative abundances at the sources are thus energy-independent, and have ratios to solar abundances as a function of first ionization potential which indicate a source temperature between 10{sup 4} and 5 x 10{sup 4} K depending on the equilibrium nature of the injection environment.
Date: March 27, 1978
Creator: Orth, Chalres D.; Ruffington, Andrew; Smoot, George F. & Mast,Terry S.
System: The UNT Digital Library
Analysis of soil-structure interaction due to ambient vibration (open access)

Analysis of soil-structure interaction due to ambient vibration

This paper presents the results of a study to evaluate the effects of soil-structure interaction (SSI) on the ambient vibration response of the switchyard/target area (S/TA) buildings at the National Ignition Facility (NIF) presently under construction at the Lawrence Livermore National Laboratory (LLNL) in Livermore, California. This laser facility houses optical and other special equipment whose alignment stability is sensitive to vibrations caused by ambient vibrations or other vibrating sources. In evaluating the deformations and displacements of the S/TA structures, the contribution of the SSI to the overall system flexibility can be very significant. The present study examines the results of fixed-base and SSI analyses of these massive stiff structures to develop an understanding of the potential contribution of SSI to the overall system displacements and deformations. A simple procedure using a set of factors is recommended for scaling the results of fixed-base analyses to approximately account for SSI effects.
Date: March 27, 1998
Creator: Tabatabaie, M., Sommer, S.C.
System: The UNT Digital Library
ANALYSIS OF VENTING OF A RESIN SLURRY (open access)

ANALYSIS OF VENTING OF A RESIN SLURRY

A resin slurry venting analysis was conducted to address safety issues associated with overpressurization of ion exchange columns used in the Purex process at the Savannah River Site (SRS). If flow to these columns were inadvertently interrupted, an exothermic runaway reaction could occur between the ion exchange resin and the nitric acid used in the feed stream. The nitric acid-resin reaction generates significant quantities of noncondensable gases, which would pressurize the column. To prevent the column from rupturing during such events, rupture disks are installed on the column vent lines. The venting analysis models accelerating rate calorimeter (ARC) tests and data from tests that were performed in a vented test vessel with a rupture disk. The tests showed that the pressure inside the test vessel continued to increase after the rupture disk opened, though at a slower rate than prior to the rupture. Calculated maximum discharge rates for the resin venting tests exceeded the measured rates of gas generation, so the vent size was sufficient to relieve the pressure in the test vessel if the vent flow rate was constant. The increase in the vessel pressure is modeled as a transient phenomenon associated with expansion of the resin slurry/gas mixture …
Date: March 27, 2012
Creator: Laurinat, J. & Hensel, S.
System: The UNT Digital Library
Automated analysis of failure event data (open access)

Automated analysis of failure event data

This paper focuses on fully automated analysis of failure event data in the concept and early development stage of a semiconductor-manufacturing tool. In addition to presenting a wide range of statistical and machine-specific performance information, algorithms have been developed to examine reliability growth and to identify major contributors to unreliability. These capabilities are being implemented in a new software package called Reliadigm. When coupled with additional input regarding repair times and parts availability, the analysis software also provides spare parts inventory optimization based on genetic optimization methods. The type of question to be answered is: If this tool were placed with a customer for beta testing, what would be the optimal spares kit to meet equipment reliability goals for the lowest cost? The new algorithms are implemented in Windows{reg_sign} software and are easy to apply. This paper presents a preliminary analysis of failure event data from three IDEA machines currently in development. The paper also includes an optimal spare parts kit analysis.
Date: March 27, 2000
Creator: Hennessy, Corey; Freerks, Fred; Campbell, James E. & Thompson, Bruce M.
System: The UNT Digital Library
B PHYSICS AT THE TEVATRON RUN II. (open access)

B PHYSICS AT THE TEVATRON RUN II.

We present the B physics results from the CDF and D0 experiments at the Tevatron Run II at Fermilab and their future prospect. This includes various B mass and lifetime measurements, B mixing, the confirmation of the discovery of the X particle, rare decays, CP violation, and spectroscopy.
Date: March 27, 2004
Creator: Yip, K.
System: The UNT Digital Library
Beam Coupling to Optical Scale Accelerating Structures (open access)

Beam Coupling to Optical Scale Accelerating Structures

Current research efforts into structure based laser acceleration of electrons utilize beams from standard RF linacs. These beams must be coupled into very small structures with transverse dimensions comparable to the laser wavelength. To obtain decent transmission, a permanent magnet quadrupole (PMQ) triplet with a focusing gradient of 560 T/m is used to focus into the structure. Also of interest is the induced wakefield from the structure, useful for diagnosing potential accelerator structures or as novel radiation sources.
Date: March 27, 2007
Creator: Sears, C. M.; Byer, R. L.; Colby, E. R.; Cowan, B. M.; Ischebeck, R.; Lincoln, M. R. et al.
System: The UNT Digital Library
Binary Microlensing Events from the MACHO Project (open access)

Binary Microlensing Events from the MACHO Project

This article presents the light curves of 21 gravitational microlensing events from the first six years of the MACHO Project gravitational microlensing survey that are likely examples of lensing by binary systems.
Date: March 27, 2000
Creator: Alcock, C.; Allsman, R. A.; Alves, D.; Axelrod, T. S.; Baines, D.; Becker, A. C. et al.
System: The UNT Digital Library
Building Public Confidence in Nuclear Activities (open access)

Building Public Confidence in Nuclear Activities

Achieving public acceptance has become a central issue in discussions regarding the future of nuclear power and associated nuclear activities. Effective public communication and public participation are often put forward as the key building blocks in garnering public acceptance. A recent international workshop in Finland provided insights into other features that might also be important to building and sustaining public confidence in nuclear activities. The workshop was held in Finland in close cooperation with Finnish stakeholders. This was most appropriate because of the recent successes in achieving positive decisions at the municipal, governmental, and Parliamentary levels, allowing the Finnish high-level radioactive waste repository program to proceed, including the identification and approval of a proposed candidate repository site. Much of the workshop discussion appropriately focused on the roles of public participation and public communications in building public confidence. It was clear that well constructed and implemented programs of public involvement and communication and a sense of fairness were essential in building the extent of public confidence needed to allow the repository program in Finland to proceed. It was also clear that there were a number of other elements beyond public involvement that contributed substantially to the success in Finland to date. …
Date: March 27, 2002
Creator: Isaacs, T
System: The UNT Digital Library
Case Study: The ''Office of Real Soon Now'' for Visualization (open access)

Case Study: The ''Office of Real Soon Now'' for Visualization

A variation on the ''Office of Real Soon Now'' has been designed and deployed at Lawrence Livermore National Laboratory (LLNL). The ASCI VIEWS (VIEWS) program [1], the element of the program developing tools for data management and visualization, is investigating a variety of display technologies, motivated in part by the large size, high resolution, and complexity of data sets that ASCI users frequently explore and analyze. While large, tiled displays have been well received at LLNL, availability and ease-of-use problems have motivated exploration of alternatives [2]. The ''Office of Real Soon Now'' Project [3, 4, 5] at the University of North Carolina at Chapel Hill (UNC) has built ''low fidelity'' versions of the ''Office of the Future'' [6, 7] that can be installed in users' offices now. At UNC, the Office of Real Soon Now installations use only a small number of relatively inexpensive projectors,generally two or three, that limit resolution and features. These projectors are connected to Microsoft Windows PCs or Apple computers that are used for daily activities, such as reading email, writing papers, and debugging programs. Even though the UNC faculty involved are predominantly computer graphics researchers, these display systems are used mainly for text-oriented applications [5]. …
Date: March 27, 2002
Creator: Uselton, S.P.
System: The UNT Digital Library
Comparing the Floating Point Systems, Inc. AP-190L to representative scientific computers: some benchmark results (open access)

Comparing the Floating Point Systems, Inc. AP-190L to representative scientific computers: some benchmark results

Results are presented of comparative timing tests made by running a typical FORTRAN physics simulation code on the following machines: DEC PDP-10 with KI processor; DEC PDP-10, KI processor, and FPS AP-190L; CDC 7600; and CRAY-1. Factors such as DMA overhead, code size for the AP-190L, and the relative utilization of floating point functional units for the different machines are discussed. 1 table.
Date: March 27, 1980
Creator: Brengle, T.A. & Maron, N.
System: The UNT Digital Library
A comparison of interface tracking methods (open access)

A comparison of interface tracking methods

In this Paper we provide a direct comparison of several important algorithms designed to track fluid interfaces. In the process we propose improved criteria by which these methods are to be judged. We compare and contrast the behavior of the following interface tracking methods: high order monotone capturing schemes, level set methods, volume-of-fluid (VOF) methods, and particle-based (particle-in-cell, or PIC) methods. We compare these methods by first applying a set of standard test problems, then by applying a new set of enhanced problems designed to expose the limitations and weaknesses of each method. We find that the properties of these methods are not adequately assessed until they axe tested with flows having spatial and temporal vorticity gradients. Our results indicate that the particle-based methods are easily the most accurate of those tested. Their practical use, however, is often hampered by their memory and CPU requirements. Particle-based methods employing particles only along interfaces also have difficulty dealing with gross topology changes. Full PIC methods, on the other hand, do not in general have topology restrictions. Following the particle-based methods are VOF volume tracking methods, which are reasonably accurate, physically based, robust, low in cost, and relatively easy to implement. Recent enhancements …
Date: March 27, 1995
Creator: Kothe, D.B. & Rider, W. J.
System: The UNT Digital Library
Coordination Chemistry of 4-Methyl-2,6,7-trioxa-1-phosphabicyclo[2,2,1]heptane: Preparation and Characterization of Ru(II) Complexes (open access)

Coordination Chemistry of 4-Methyl-2,6,7-trioxa-1-phosphabicyclo[2,2,1]heptane: Preparation and Characterization of Ru(II) Complexes

Article discussing preparation and characterization of Ru(II) complexes.
Date: March 27, 2012
Creator: Joslin, Evan E.; McMullin, Claire L.; Gunnoe, T. Brent; Cundari, Thomas R., 1964-; Sabat, Michal & Myers, William H.
System: The UNT Digital Library
Coupled Reservoir-Geomechanical Analysis of the Potential for Tensile and Shear Failure Associated With CO2 Injection in Multilayered Reservoir-Caprock Systems (open access)

Coupled Reservoir-Geomechanical Analysis of the Potential for Tensile and Shear Failure Associated With CO2 Injection in Multilayered Reservoir-Caprock Systems

Coupled reservoir-geomechanical simulations were conductedto study the potential for tensile and shear failure e.g., tensilefracturing and shear slip along pre-existing fractures associated withunderground CO2 injection in a multilayered geological system. Thisfailure analysis aimed to study factors affecting the potential forbreaching a geological CO2 storage system and to study methods forestimating the maximum CO2 injection pressure that could be sustainedwithout causing such a breach. We pay special attention to geomechanicalstress changes resulting from upward migration of the CO2 and how theinitial stress regime affects the potential for inducing failure. Weconclude that it is essential to have an accurate estimate of thethree-dimensional in situ stress field to support the design andperformance assessment of a geological CO2 injection operation. Moreover,we also conclude that it is important to consider mechanical stresschanges that might occur outside the region of increased reservoir fluidpressure (e.g., in the overburden rock) between the CO2-injectionreservoir and the ground surface.
Date: March 27, 2007
Creator: Rutqvist, J.; Birkholzer, J. T. & Tsang, C.-F.
System: The UNT Digital Library
Deformation behavior and strengthening effects of an eutectic AlCoCrFeNi2.1 high entropy alloy probed by in-situ synchrotron X-ray diffraction and post-mortem EBSD (open access)

Deformation behavior and strengthening effects of an eutectic AlCoCrFeNi2.1 high entropy alloy probed by in-situ synchrotron X-ray diffraction and post-mortem EBSD

Article describes how high energy synchrotron X-ray diffraction was used during tensile testing of an as-cast eutectic AlCoCrFeNi2.1 high entropy alloy. The authors determine for the first time the volume fractions of existing phases, and they further detail their role on the alloy deformation behavior.
Date: March 27, 2023
Creator: Shen, Jiajia; Lopes, J.G.; Zeng, Zhi; Choi, Yeon Taek; Maawad, E.; Schell, N. et al.
System: The UNT Digital Library
Dimming Every Light Cheaply (open access)

Dimming Every Light Cheaply

This paper discusses the successful development and testing of the first ballast/IBECS network interface that will allow commercially-available controllable ballasts to be operated from the Internet via IBECS (Integrated Building Environmental Communications System). The interface, which is expected to cost original equipment manufacturers (OEMs) only about $1-2/unit, has been hardened so that it is impervious to electronic noise generated by most 0-10 VDC controllable ballasts.
Date: March 27, 2002
Creator: Rubinstein, Francis; Pettler, Peter & Jennings, Judith
System: The UNT Digital Library
Dynamic Conductance of Carbon Nanotubes (open access)

Dynamic Conductance of Carbon Nanotubes

Article on dynamic conductance of carbon nanotubes.
Date: March 27, 2000
Creator: Roland, Christopher; Buongiorno Nardelli, Marco; Wang, Jian & Guo, Hong
System: The UNT Digital Library
Effects of Pressure and Temperature on the Thermal Properties of a Salt and a Quartz Monzonite (open access)

Effects of Pressure and Temperature on the Thermal Properties of a Salt and a Quartz Monzonite

Measurements have been made of thermal conductivity, diffusivity, and linear expansion as a function of temperature (to 573 K) and hydrostatic pressure (to 50 MPa) on two rocks, Avery Island domal salt and Climax Stock quartz monzonite. For Avery Island salt the thermal properties do not show any pressure dependence and are approximately the same values as for single crystal halite at 0.1 MPa. The lack of pressure dependence is attributed to the high symmetry of halite (cubic) and to its low strength, both of which inhibit brittle fracturing. For Climax Stock quartz monzonite no pressure dependence of thermal diffusivity has been resolved, but conductivity does show a drop of approximately 10% with decreasing pressure from 50 to 3 MPa. The pressure dependence is not measurably altered by heating the rock to as high as 473 K under 50 MPa. Our measurements so far on the thermal conductivity of quartz monzonite vs temperature and pressure are in agreement with predictions of the Walsh and Decker (1966) model of thermal conductivity vs crack porosity based on independent measurements of crack porosity vs temperature and pressure for the same quartz monzonite. Heating to temperatures greater than 473 K at 50 MPa, or …
Date: March 27, 1981
Creator: Durham, W. B. & Abey, A. E.
System: The UNT Digital Library
Efficient computation of periodic and nonperiodic Green`s functions in layered media using the MPIE (open access)

Efficient computation of periodic and nonperiodic Green`s functions in layered media using the MPIE

The mixed potential integral equation (MPIE) formulation is convenient for problems involving layered media because potential quantities involve low order singularities, in comparison to field quantities. For nonperiodic problems, the associated Green`s potentials involve spectral integrals of the Sommerfeld type, in the periodic case, discrete sums over sampled values of the same spectra are required. When source and observation points are in the same or in adjacent layers, the convergence of both representations is enhanced by isolating the direct and quasi-static image contributions associated with the nearby layers. In the periodic case, the convergence of direct and image contributions may be rapidly accelerated by means of the Ewadd method.
Date: March 27, 1998
Creator: Wilton, D. R.; Jackson, D. R. & Champagne, N. J.
System: The UNT Digital Library
Electron Bunch Length Measurements in the E-167 Plasma Wakefield Experiment (open access)

Electron Bunch Length Measurements in the E-167 Plasma Wakefield Experiment

Bunch length is of prime importance to beam driven plasma wakefield acceleration experiments due to its inverse relationship to the amplitude of the accelerating wake. We present here a summary of work done by the E167 collaboration measuring the SLAC ultra-short bunches via autocorrelation of coherent transition radiation. We have studied material transmission properties and improved our autocorrelation traces using materials with better spectral characteristics.
Date: March 27, 2007
Creator: Blumenfeld, I.; Auerbach, D.; Berry, M.; Clayton, C. E.; Decker, F. J.; Hogan, M. J. et al.
System: The UNT Digital Library
Energetic charged particle beams for disablement of mines (open access)

Energetic charged particle beams for disablement of mines

LLNL has an ongoing program of weapons disablement using energetic charged particle beams; this program combines theoretical and experimental expertise in accelerators, high-energy and nuclear physics, plasma physics and hydrodynamics to simulate/measure effects of electron and proton beams on weapons. This paper reviews work by LLNL, LANL and NSWC on detonating sensitive and insensitive high explosives and land mines using high-current electron beams. Computer simulations are given. 20--160 MeV electron beams incident on wet/dry soils are being studied, along with electron beam propagation in air. Compact high current, high energy accelerators are being developed for mine clearing. Countermine missions of interest are discussed. 25 refs., 9 figs.
Date: March 27, 1995
Creator: Wuest, C.R.
System: The UNT Digital Library
Estimation of fatigue crack initiation in austenitic stainless steels in LWR environments. (open access)

Estimation of fatigue crack initiation in austenitic stainless steels in LWR environments.

None
Date: March 27, 2002
Creator: Chopra, O. K.
System: The UNT Digital Library
Experimental test accelerator (ETA) (open access)

Experimental test accelerator (ETA)

The Lawrence Livermore Laboratory is constructing an induction linac with the following parameters 10kA, 50ns FWHM pulse width, 5MeV, and 5PPS. This paper describes the design features of the 2.5 MeV injector and it's associated pulsed power system.
Date: March 27, 1979
Creator: Hester, R. E.; Bubp, D. G.; Clark, J. C.; Chesterman, A. W.; Cook, E. G.; Dexter, W. L. et al.
System: The UNT Digital Library
Externally Dispersed Interferometry for Precision Radial Velocimetry (open access)

Externally Dispersed Interferometry for Precision Radial Velocimetry

Externally Dispersed Interferometry (EDI) is the series combination of a fixed-delay field-widened Michelson interferometer with a dispersive spectrograph. This combination boosts the spectrograph performance for both Doppler velocimetry and high resolution spectroscopy. The interferometer creates a periodic spectral comb that multiplies against the input spectrum to create moire fringes, which are recorded in combination with the regular spectrum. The moire pattern shifts in phase in response to a Doppler shift. Moire patterns are broader than the underlying spectral features and more easily survive spectrograph blurring and common distortions. Thus, the EDI technique allows lower resolution spectrographs having relaxed optical tolerances (and therefore higher throughput) to return high precision velocity measurements, which otherwise would be imprecise for the spectrograph alone.
Date: March 27, 2007
Creator: Erskine, D. J.; Muterspaugh, M. W.; Edelstein, J.; Lloyd, J.; Herter, T.; Feuerstein, W. M. et al.
System: The UNT Digital Library