Particle Correlations with the PHENIX Experiment (open access)

Particle Correlations with the PHENIX Experiment

Results of identical pion correlations from the first year of data collection with the PHENIX detector at RHIC ({radical}S{sub NN} = 130 GeV) are presented. PHENIX has good particle identification using an electromagnetic calorimeter for timing, leading to identified pions from .2 to 1 GeV/c. This extends the range of previously measured correlation radii at this energy to (k{sub T}) = 633MeV/c. The beam energy dependence of the HBT radii are studied in depth and no significant dependence of the transverse radii is present. The longitudinal correlation length has a moderate energy dependence. Furthermore, theoretical predictions of R{sub out}/R{sub side} severely underpredict the measured ratio, which is consistent with unity for all k{sub T}. The implications of these results are considered.
Date: January 20, 2002
Creator: Johnson, S C
Object Type: Article
System: The UNT Digital Library
Data Management Guide Version 1.5.3 (open access)

Data Management Guide Version 1.5.3

The FEMIS Data Management Guide provides the information needed to manage the data used to support the administrative, user-environment, database management, and operational capabilities of FEMIS.
Date: November 20, 2002
Creator: Burnett, Robert A.; Carter, Richard J.; Holter, Nancy A.; Johnson, Daniel M.; Johnson, Ranata L.; Johnson, Sharon M. et al.
Object Type: Text
System: The UNT Digital Library
Dispersion of Extensional and Torsional Waves in Porous Cylinders with Patchy Saturation (open access)

Dispersion of Extensional and Torsional Waves in Porous Cylinders with Patchy Saturation

Laboratory experiments on wave propagation through saturated and partially saturated porous media have often been conducted on porous cylinders that were initially fully saturated and then allowed to dry while continuing to acquire data on the wave behavior. Since it is known that drying typically progresses from the outside to the inside, a sensible physical model of this process is concentric cylinders having different saturation levels--the simplest example being a fully dry outer cylindrical shell together with a fully wet inner cylinder. We use this model to formulate the equations for wave dispersion in porous cylinders for patchy saturation (i.e., drainage) conditions. In addition to multiple modes of propagation obtained numerically from these dispersion relations, we find two distinct analytical expressions for torsional wave modes.
Date: March 20, 2002
Creator: Berryman, J G & Pride, S R
Object Type: Article
System: The UNT Digital Library
Nanoscale Bio-Molecular Control Using EC-OWLS (open access)

Nanoscale Bio-Molecular Control Using EC-OWLS

A recently developed technique termed ''Electrochemical Optical Waveguide Lightmode Spectroscopy'' (EC-OWLS) [1] combines evanescent-field optical sensing with electrochemical control of surface adsorption processes. Initial EC-OWLS investigations efficiently monitored molecular surface adsorption and layer thickness changes of an adsorbed polymer layer examined in situ as a function of potential applied to a waveguide1. A layer of indium tin oxide (ITO) served as both a high refractive index waveguide for optical sensing, and a conductive electrode; an electrochemical flow-through fluid cell incorporated working, reference and counter electrodes. Poly(L-lysine)-grafted-poly(ethylene glycol) (PLL-g-PEG) served as a model, polycation adsorbate. Results indicate that adsorption and desorption of PLL-g-PEG from aqueous buffer are a function of applied potential, and that binding events subsequent to PLL-g-PEG functionalization are dependent on reorganization in the molecular adlayer.
Date: November 20, 2002
Creator: Bearinger, J P; Voros, J; Hubbell, J A & Textor, M
Object Type: Article
System: The UNT Digital Library
Metallization and Dissociation of Fluid Hydrogen and Other Diatomics at 100 GPa Pressures (open access)

Metallization and Dissociation of Fluid Hydrogen and Other Diatomics at 100 GPa Pressures

Dynamic compression of diatomic liquids using both single-shock (Hugoniot) and multiple-shock (reverberating-shock) compression achieves pressures which range up to a few 100 GPa (Mbar), densities as high as tenfold of initial liquid density in hydrogen, and temperatures up to several 1000 K. Single-shock compression produces substantial heating, which causes a limiting compression. Multiple-shock compression is quasi-isentropic, which achieves lower temperatures and higher densities than single shocks, and has no limiting compression. Diatomic fluids have universal behaviors under dynamic compression. Under multiple-shock compression, these fluids undergo a density-driven nonmetal-metal Mott transitions with common density scaling. Under single-shock compression, these fluids have essentially the same Hugoniot in velocity space. D{sub 2} undergoes temperature-driven dissociation to a poor metal at {approx}50 GPa. These results provide insight into which of the two published D{sub 2} Hugoniots is probably correct.
Date: September 20, 2002
Creator: Nellis, W J
Object Type: Article
System: The UNT Digital Library
Ribbon Fiber with Multiple Antiguided Phase-Locked Gain Cores (open access)

Ribbon Fiber with Multiple Antiguided Phase-Locked Gain Cores

We report on the first experimental demonstration of a scalable fiber laser approach based on phase-locking multiple gain cores in an antiguided structure. A novel fabrication technology is used with soft glass components to construct the multiple core fiber used in our experiments. The waveguide region is rectangular in shape and comprised of a periodic sequence of gain and no-gain segments having nearly uniform refractive index. The rectangular waveguide is itself embedded in a lower refractive index cladding region. Experimental results confirm that our five-core Nd doped glass prototype structure runs predominantly in two spatial antiguided modes as predicted by our modeling.
Date: November 20, 2002
Creator: Beach, R J; Feit, M D; Mitchell, S C; Cutter, K P; Dawson, J W & Payne, S A
Object Type: Article
System: The UNT Digital Library
System Administration Guide Version 1.5.3 (open access)

System Administration Guide Version 1.5.3

The FEMIS System Administration Guide provides information on FEMIS System Administrator activities as well as the utilities that are included with FEMIS.
Date: November 20, 2002
Creator: Burnett, Robert A.; Carter, Richard J.; Downing, Timothy R.; Homer, Brian J.; Holter, Nancy A.; Johnson, Daniel M. et al.
Object Type: Text
System: The UNT Digital Library
Installation Guide Version 1.5.3 (open access)

Installation Guide Version 1.5.3

The FEMIS Installation Guide provides instructions for installing and configuring the FEMIS software package.
Date: November 20, 2002
Creator: Burnett, Robert A.; Carter, Richard J.; Homer, Brian J.; Johnson, Daniel M.; Johnson, Ranata L.; Johnson, Sharon M. et al.
Object Type: Text
System: The UNT Digital Library
Comparison of Implicit and Symbolic Implicit Monte Carlo Line Transport With Frequency Weight Vector Extension (open access)

Comparison of Implicit and Symbolic Implicit Monte Carlo Line Transport With Frequency Weight Vector Extension

We compare the Implicit Monte Carlo (IMC) technique to the Symbolic IMC (SIMC) technique, with and without weight vectors in frequency space, for time-dependent line transport in the presence of collisional pumping. We examine the efficiency and accuracy of the IMC and SIMC methods for examples involving the evolution of a collisionally pumped trapping problem to steady-state, the surface heating of cold media by a beam, and the diffusion of energy from a localized region that is collisionally pumped. The importance of spatial biasing and teleportation for problems involving high opacity is demonstrated. Our numerical solution, along with its associated teleportation error, is checked against theoretical calculations for the last example.
Date: March 20, 2002
Creator: McKinley, M. S.; Brooks, E. D., III & Szoke, A.
Object Type: Report
System: The UNT Digital Library
Analysis of Induced Gas Released During Retrieval of Hanford Double-Shell Tank Waste (open access)

Analysis of Induced Gas Released During Retrieval of Hanford Double-Shell Tank Waste

Radioactive waste is scheduled to be retrieved from Hanford double-shell tanks AN-103, AN-104, AN-105 and AW-101 to the vitrification plant beginning about 2009. Retrieval may involve decanting the supernatant liquid and/or mixing the waste with jet pumps. In these four tanks, which contain relatively large volumes of retained gas, both of these operations are expected to induce buoyant displacement gas releases that can potentially raise the tank headspace hydrogen concentration to very near the lower flammability limit. This report describes the theory and detailed physical models for both the supernate decant and jet mixing processes and presents the results from applying the models to these operations in the four tanks. The technical bases for input parameter distributions are elucidated.
Date: March 20, 2002
Creator: Wells, Beric E. (BATTELLE (PACIFIC NW LAB)); Cuta, Judith M. (BATTELLE (PACIFIC NW LAB)); Hartley, Stacey A. (BATTELLE (PACIFIC NW LAB)); Mahoney, Lenna A. (BATTELLE (PACIFIC NW LAB)); Meyer, Perry A. (BATTELLE (PACIFIC NW LAB)) & Stewart, Charles W. (BATTELLE (PACIFIC NW LAB))
Object Type: Report
System: The UNT Digital Library
Final Report: Deconvolution of Adaptive Optics Images of Titan, Neptune, and Uranus (open access)

Final Report: Deconvolution of Adaptive Optics Images of Titan, Neptune, and Uranus

This project involved images of Titan, Neptune, and Uranus obtained using the 10-meter W.M. Keck II Telescope and its adaptive optics system. An adaptive optics system corrects for turbulence in the Earth's atmosphere by sampling the wavefront and applying a correction based on the distortion measured for a known source within the same isoplanatic patch as the science target (for example, a point source such as a star). Adaptive optics can achieve a 10-fold increase in resolution over that obtained by images without adaptive optics (for example, Saturn's largest moon Titan is unresolved without adaptive optics but at least 10 resolution elements can be obtained across the disk in Keck adaptive optics images). The adaptive optics correction for atmospheric turbulence is not perfect; a point source is converted to a diffraction-limited core surrounded by a ''halo''. This halo is roughly the size and shape of the uncorrected point spread function one would observe without adaptive optics. In order to enhance the sharpness of the Keck images it is necessary to apply a deconvolution algorithm to the data. Many such deconvolution algorithms exist such as maximum likelihood and maximum entropy. These algorithms suffer to various degrees from noise amplification and creation …
Date: December 20, 2002
Creator: Gibbard, S & Marchis, F
Object Type: Report
System: The UNT Digital Library
Projected Response of Typical Detonators to Electrostatic Discharge (ESD) Environments (open access)

Projected Response of Typical Detonators to Electrostatic Discharge (ESD) Environments

The purpose of this discussion is to indicate the threshold values for low-order detonator response by using first principles applied to pin-to-pin configurations and associated limits in pin-to-case scenarios. In addition an attempt to define the electrical environment by first principles is shown to be inadequate and indicates the need to define the electrical insult by reasonable standards. A comparison of two accepted electrical models and a combination of the extreme reported levels from both standards are used to establish an extreme set of parameters for a safety assessment. A simplification of the critical electrical insult parameters is then shown and demonstrated to provide the initial screening protocol with easily defined electrical dimensions of action integral. Action integral and the conductive material properties are the basic parameters needed to define the solid, liquid, and gas phases of the material used for detonator bridge wires. The resulting material phases are directly related to detonator response thresholds. The discussion concludes by showing the ability of ESD insults to arc from pin-to-case, the limited knowledge of the associated arc initiation process, and the modeling need for a reasonable arc resistance in pin-to-case scenarios.
Date: December 20, 2002
Creator: Wilson, M. J.
Object Type: Report
System: The UNT Digital Library
Estimated Costing of an EUV Mask Inspection Microscope (open access)

Estimated Costing of an EUV Mask Inspection Microscope

This document is the fourth sub-report of the EUV AIM design study being conducted at LLNL on behalf of International SEMATECH (ISMT) and addresses the issue of preliminary system costing. The purpose of the LLNL study, as identified in section 1.2 of the statement of work, is to research the basic user requirements of an actinic defect characterization tool, potential design configurations and top-level specifications. The objectives of this design study specifically identified in section 1.3 of the statement of work were to: (1) Determine the user requirements of an actinic defect characterization tool; (2) Determine if an EUV AIM tool is an appropriate platform for actinic defect characterization; (3) Determine possible design configurations and top-level performance specifications; (4) Identify potential technical issues and risks of different technical approaches; (5) Provide estimates of cost relating to different technical approaches; and (6) Provide simulated performance for key subsystems and the entire system. The sub-sections of the study to be addressed were accordingly defined in the statement of work as being: (1) Formulation of top-level specifications; (2) Identification of system configurations suitable for meeting the top-level specifications; (3) Preliminary design of imaging systems; (4) Preliminary design of illumination systems; (5) Prediction and …
Date: August 20, 2002
Creator: Barty, A. & Taylor, J. S.
Object Type: Report
System: The UNT Digital Library
Groundwater Protection Program Science and Technology Summary Description (open access)

Groundwater Protection Program Science and Technology Summary Description

The Hanford Site Groundwater Protection Program, formerly the Groundwater/Vadose Zone Integration Project, was established in 1997 to develop the integrated approach, technical capability, and scientific information needed to perform site-wide assessments of the potential effects of Hanford Site soil and groundwater contaminants on people and the ecology. To complete this mission, gaps in scientific understanding and technologies were identified, and research to close those gaps was initiated.
Date: November 20, 2002
Creator: Freshley, Mark D.; Bunn, Amoret L.; Gee, Glendon W.; Gilmore, Tyler J.; Kincaid, Charles T.; Peterson, Robert E. et al.
Object Type: Report
System: The UNT Digital Library
Pipeline Cross-Site Transfer Assessment for Tank 241-SY-101 Waste (open access)

Pipeline Cross-Site Transfer Assessment for Tank 241-SY-101 Waste

This study evaluated the feasibility of transferring waste now stored in Tank SY-101 in the 200 West Area of the Hanford Site to a storage tank in 200 East Area through a 6.2-mile-long, 3-inch-diameter stainless steel pipeline. Using the Wasp slurry transport model, the critical velocity and expected pressure drop were calculated to determine 1) whether current SY-101 waste can be transferred through the existing cross-site transfer pipeline without additional dilution and, if it is not possible, how much dilution is needed.
Date: February 20, 2002
Creator: Onishi, Yasuo; Wells, Beric E.; Hartley, Stacey A. & Cooley, Scott K.
Object Type: Report
System: The UNT Digital Library
Laboratory Directed Research and Development FY2001 Annual Report (open access)

Laboratory Directed Research and Development FY2001 Annual Report

Established by Congress in 1991, the Laboratory Directed Research and Development (LDRD) Program provides the Department of Energy (DOE)/National Nuclear Security Administration (NNSA) laboratories, like Lawrence Livermore National Laboratory (LLNL or the Laboratory), with the flexibility to invest up to 6% of their budget in long-term, high-risk, and potentially high payoff research and development (R&D) activities to support the DOE/NNSA's national security missions. By funding innovative R&D, the LDRD Program at LLNL develops and extends the Laboratory's intellectual foundations and maintains its vitality as a premier research institution. As proof of the Program's success, many of the research thrusts that started many years ago under LDRD sponsorship are at the core of today's programs. The LDRD Program, which serves as a proving ground for innovative ideas, is the Laboratory's most important single resource for fostering excellent science and technology for today's needs and tomorrow's challenges. Basic and applied research activities funded by LDRD enhance the Laboratory's core strengths, driving its technical vitality to create new capabilities that enable LLNL to meet DOE/NNSA's national security missions. The Program also plays a key role in building a world-class multidisciplinary workforce by engaging the Laboratory's best researchers, recruiting its future scientists and engineers, …
Date: June 20, 2002
Creator: Al-Ayat, R
Object Type: Report
System: The UNT Digital Library
Design and Evaluation of System Configurations for an EUV Mask Inspection Microscope (open access)

Design and Evaluation of System Configurations for an EUV Mask Inspection Microscope

This document is the third sub-report of the EUV AIM design study being conducted at LLNL on behalf of International Sematech (ISMT). The purpose of this study as identified in section 1.2 of the statement of work is to research the basic user requirements of an actinic defect characterization tool, potential design configurations and top-level specifications. The objectives of this design study specifically identified in section 1.3 of the statement of work were to: (1) Determine the user requirements of an actinic defect characterization tool; (2) Determine if an EUV AIM tool is an appropriate platform for actinic defect characterization; (3) Determine possible design configurations and top-level performance specifications; (4) Identify potential technical issues and risks of different technical approaches; (5) Provide estimates of cost relating to different technical approaches; and (6) Provide simulated performance for key subsystems and the entire system. The sub-sections of the study to be addressed were accordingly defined in the statement of work as being: (1) Formulation of top-level specifications; (2) Identification of system configurations suitable for meeting the top-level specifications; (3) Preliminary design of imaging systems; (4) Preliminary design of illumination systems; (5) Prediction and comparison of performance through aerial image calculation; (6) Identification …
Date: August 20, 2002
Creator: Barty, Anton; Taylor, John S.; Hudyma, Russell & Spiller, Eberhard
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Simulating Fertilization of the Ocean as a Carbon Sequestration Strategy: Effectiveness and Unintended Consequences (open access)

Simulating Fertilization of the Ocean as a Carbon Sequestration Strategy: Effectiveness and Unintended Consequences

The primary objectives of this project are to assess, and improve our understanding of: (1) The effectiveness of various strategies to intentionally store carbon in the ocean through fertilization of the surface ocean with iron and/or macronutrients; and (2) Unanticipated environmental consequences of these ocean fertilization strategies. We propose to use what may be the best global ocean biogeochemical model in the world (PISCES) and apply it to perform the most realistic global-scale simulations of various iron fertilization scenarios. Versions of PISCES are currently used by MPI in Germany and IPSL in France. The model represents diatoms, coccolithophorids, and two classes of zooplankton. This model considers Fey N, P, O{sub 2}, Si, alkalinity, and carbon; for some of these it considers dissolved inorganic and organic, as well as particulate, forms. We would install the PISCES model with a minimum of modification into the LLNL ocean model, and perform an initial suite of simulations of both iron fertilization experiments (e.g., SOFeX) and proposed iron fertilization strategies. Based on the simulated experiments, we will analyze model deficiencies with respect to the observations and use this analysis to improve future versions of the model. The source code for and results from this set …
Date: March 20, 2002
Creator: Caldeira, K
Object Type: Report
System: The UNT Digital Library
Arbitrary Order Hierarchical Bases for Computational Electromagnetics (open access)

Arbitrary Order Hierarchical Bases for Computational Electromagnetics

We present a clear and general method for constructing hierarchical vector bases of arbitrary polynomial degree for use in the finite element solution of Maxwell's equations. Hierarchical bases enable p-refinement methods, where elements in a mesh can have different degrees of approximation, to be easily implemented. This can prove to be quite useful as sections of a computational domain can be selectively refined in order to achieve a greater error tolerance without the cost of refining the entire domain. While there are hierarchical formulations of vector finite elements in publication (e.g. [1]), they are defined for tetrahedral elements only, and are not generalized for arbitrary polynomial degree. Recently, Hiptmair, motivated by the theory of exterior algebra and differential forms presented a unified mathematical framework for the construction of conforming finite element spaces [2]. In [2], both 1-form (also called H(curl)) and 2-form (also called H(div)) conforming finite element spaces and the definition of their degrees of freedom are presented. These degrees of freedom are weighted integrals where the weighting function determines the character of the bases, i.e. interpolatory, hierarchical, etc.
Date: December 20, 2002
Creator: Rieben, R N; White, D & Rodrigue, G
Object Type: Article
System: The UNT Digital Library
Target Physics (open access)

Target Physics

Inertial fusion targets can be categorized by the ignition scheme, the implosions mechanism and the driver technology used to supply the compression and the ignition energy. We will briefly review each of these elements. There are two ignition methods currently being considered. The first, called hotspot ignition, heats a central core of the compressed fuel to ignition temperatures. The assembly of a sufficiently large hotspot is accomplished by stagnation of a convergent flow. The assembled configuration of the hotspot, and surrounding compressed, low temperature fuel, will be approximately isobaric. The second ignition technique, called fast ignition, heats cold compressed fuel to ignition temperatures directly with an external source of heat. This technique has become practicable by the advent of short-pulse, high-intensity lasers using chirped-pulse-amplification (CPA), that can compress laser pulses to extremely high power. If focused appropriately, these fast-ignition laser beams can provide the same power densities as result from the hydrodynamic flow stagnation of the first technique. Inertial fusion fuel can be compressed by two techniques, referred to as direct and indirect drive. Directly driven capsules directly absorb energy delivered by the external compression driver and use it to implode the fusion fuel. Indirectly driven targets absorb the external …
Date: July 20, 2002
Creator: Tabak, M
Object Type: Article
System: The UNT Digital Library
Summary of Hanford Subsurface Air Flow and Extraction (SAFE) Activities for Fiscal Year 2002 (open access)

Summary of Hanford Subsurface Air Flow and Extraction (SAFE) Activities for Fiscal Year 2002

Potential leak detection, monitoring, and mitigation techniques are being developed to support Hanford single-shell tank waste retrieval operations. In July and August 2001, Pacific Northwest National Laboratory demonstrated several of these technologies for CH2M HILL Hanford Group, Inc., at the Mock Tank Site in the 200 East Area. These subsurface air flow and extraction (SAFE) technologies use air injection and extraction wells to create an advective air flowfield beneath a tank. SAFE includes the following technologies: 1) leak detection--in-tank tracers, flowfield disturbance, radon displacement, and tank waste vapors; 2) leak monitoring--partitioning tracer method and reactive tracers; 3) leak mitigation--soil desiccation before and after leakage and in situ gaseous reduction; and 4) subsurface characterization--interfacial tracers. This report provides an overview of these technologies and discusses the FY 2001 demonstration activities at the Mock Tank Site, their results, and implications for future work.
Date: March 20, 2002
Creator: Cameron, Richard J.; Evans, John C.; Johnson, Michael D. & Liikala, Terry L.
Object Type: Report
System: The UNT Digital Library
Groundwater Chemistry and Hydrogeology of the Upper Saddle Mountains Basalt-Confined Aquifer South and Southeast of the Hanford Site (open access)

Groundwater Chemistry and Hydrogeology of the Upper Saddle Mountains Basalt-Confined Aquifer South and Southeast of the Hanford Site

This report describes groundwater monitoring within the upper basalt-confined aquifer in areas bordering the Hanford Site to the south and southeast. The purpose of the sample was to demonstrate that constituents analyzed were within the range of background concentrations and to evaluate any potential connection between groundwater on and off the Hanford Site.
Date: November 20, 2002
Creator: Newcomer, Darrell R. (BATTELLE (PACIFIC NW LAB)); Thornton, Edward C. (BATTELLE (PACIFIC NW LAB)) & Liikala, Terry L. (BATTELLE (PACIFIC NW LAB))
Object Type: Report
System: The UNT Digital Library
Experience and Operational Improvements, Mixer Pump Performance (open access)

Experience and Operational Improvements, Mixer Pump Performance

Millions of gallons of radioactive waste are stored in large underground tanks at DOE sites. The waste is made up of settled solids, in sludge form, at the bottom of the tank and a layer of supernatant liquid on top of it. It is necessary to mix the solids in the sludge layer with the supernatant liquid to facilitate their removal from the storage tanks for remediation. Our goal is to improve the mobilization of the settled solids by optimizing mixing with the supernatant liquid and preserving the mobility of the solids. This report investigates whether time-phase separation between pump head oscillations affects overall sludge mobilization. If a mixing jet from one pump happens to follow temporarily the path of the lead mixing jet, it may be possible to prevent or slow down the resettling of the heavy solid particles, maintaining them in suspension. If a retrieval pump were operating at the same time, it could facilitate removal of such particles. Preliminary experiments were carried out to observe whether time-phase separation has some influence on the overall mobilization. A brief account is presented of the successful mobilization and removal of most of the radioactive waste from Tank D8-2 at the …
Date: March 20, 2002
Creator: Erian, Fadel F.; Mullen, O Dennis & Kellogg, Michael I.
Object Type: Report
System: The UNT Digital Library
Effect of Design Changes On Remote Handled Trench Waste Form Release Calculations (open access)

Effect of Design Changes On Remote Handled Trench Waste Form Release Calculations

A set of reactive chemical transport calculations was conducted with the Subsurface Transport Over Reactive Multi-phases (STORM) code to evaluate the long-term performance of a representative low-activity waste glass in a shallow subsurface disposal system located on the Hanford Site. One-dimensional simulations were conducted out to times of 20,000 yr. The simulations predict a lower release rate for the new trench design (0.605 ppm/yr) than for the old trench design (0.726 ppm/yr). Because the glass corrosion rate is significantly higher at the backfill/glass interfaces, having one less interface with the 3-layer design offsets the effect of the slightly higher pH relative to the 4-layer design. The differences between the old and new trench designs were much less significant than differences due to differences in recharge rate.
Date: September 20, 2002
Creator: Bacon, Diana H. & McGrail, B. Peter
Object Type: Report
System: The UNT Digital Library