Towards a perturbative theory of nuclear forces (open access)

Towards a perturbative theory of nuclear forces

The authors show that an expansion of nuclear forces about the chiral limit is formally consistent and is equivalent to KSW power counting in the {sup 1}S{sub 0} channel and Weinberg power counting in the {sup 3}S{sub 1}--{sup 3}D{sub 1} coupled channels. Numerical evidence suggests that this expansion converges. The feasibility of making contact between nuclear physics and lattice-QCD simulations is discussed.
Date: January 6, 2001
Creator: Beane, S. R.; Bedaque, P. F.; Savage, M. J. & van Kolck, U.
Object Type: Report
System: The UNT Digital Library
ADVANCED EMISSIONS CONTROL DEVELOPMENT PROGRAM (open access)

ADVANCED EMISSIONS CONTROL DEVELOPMENT PROGRAM

The primary objective of the Advanced Emissions Control Development Program (AECDP) is to develop practical, cost-effective strategies for reducing the emissions of hazardous air pollutants (HAPs, or air toxics) from coal-fired boilers. The project goal is to effectively control air toxic emissions through the use of conventional flue gas cleanup equipment such as electrostatic precipitators (ESPs), fabric filters (baghouses), and wet flue gas desulfurization (WFGD) systems. Development work initially concentrated on the capture of trace metals, fine particulate, hydrogen chloride, and hydrogen fluoride. Recent work has focused almost exclusively on the control of mercury emissions.
Date: February 6, 2001
Creator: Farthing, G.A.
Object Type: Report
System: The UNT Digital Library
The Development of an Effective Transportation Risk Assessment Model for Analyzing the Transport of Spent Fuel and High-Level Radioactive Waste to the Proposed Yucca Mountain Repository (open access)

The Development of an Effective Transportation Risk Assessment Model for Analyzing the Transport of Spent Fuel and High-Level Radioactive Waste to the Proposed Yucca Mountain Repository

Past approaches for assessing the impacts of transporting spent fuel and high-level radioactive waste have not been effectively implemented or have used relatively simple approaches. The Yucca Mountain Draft Environmental Impact Statement (DEIS) analysis considers 83 origins, 34 fuel types, 49,914 legal weight truck shipments, 10,911 rail shipments, consisting of 59,250 shipment links outside Nevada (shipment kilometers and population density pairs through urban, suburban or rural zones by state), and 22,611 shipment links in Nevada. There was additional complexity within the analysis. The analysis modeled the behavior of 41 isotopes, 1091 source terms, and used 8850 food transfer factors (distinct factors by isotope for each state). The model also considered different accident rates for legal weight truck, rail, and heavy haul truck by state, and barge by waterway. To capture the all of the complexities of the transportation analysis, a Microsoft{reg_sign} Access database was created. In the Microsoft{reg_sign} Access approach the data is placed in individual tables and equations are developed in queries to obtain the overall impacts. While the query might be applied to thousands of table entries, there is only one equation for a particular impact. This greatly simplifies the validation effort. Furthermore, in Access, data in tables …
Date: February 6, 2001
Creator: McSweeney; Thomas; Winnard; Ross; B., Steven; Best et al.
Object Type: Report
System: The UNT Digital Library
Explosion-induced combustion of hydrocarbon clouds in a chamber (open access)

Explosion-induced combustion of hydrocarbon clouds in a chamber

The interaction of the detonation of a solid HE-charge with a non-premixed cloud of hydro-carbon fuel in a chamber was studied in laboratory experiments. Soap bubbles filled with a flammable gas were subjected to the blast wave created by the detonation of PETN-charges (0.2 g < mass < 0.5 g). The dynamics of the combustion system were investigated by means of high-speed photography and measurement of the quasi-static chamber pressure.
Date: February 6, 2001
Creator: Neuwald, P; Reichenbach, H & Kuhl, A L
Object Type: Article
System: The UNT Digital Library
Material Corrosion and Plate-Out Test of Types 304L and 316L Stainless Steel (open access)

Material Corrosion and Plate-Out Test of Types 304L and 316L Stainless Steel

Corrosion and plate-out tests were performed on 304L and 316L stainless steel in pretreated Envelope B and Envelope C solutions. Flat coupons of the two stainless steels were exposed to 100 degrees C liquid and to 74 degrees C and 88 degrees C vapor above the solutions for 61 days. No significant corrosion was observed either by weight-loss measurements or by microscopic examination. Most coupons had small weight gains due to plate-out of solids, which remained to some extent even after 24-hour immersion in 1 N nitric acid at room temperature. Plate-out was more significant in the Envelope B coupons, with film thickness from less than 0.001 in. to 0.003-inches.
Date: February 6, 2001
Creator: Zapp, P.E.
Object Type: Report
System: The UNT Digital Library
Metastable metallic hydrogen glass (open access)

Metastable metallic hydrogen glass

The quest for metallic hydrogen has been going on for over one hundred years. Before hydrogen was first condensed into a liquid in 1898, it was commonly thought that condensed hydrogen would be a metal, like the monatomic alkali metals below hydrogen in the first column of the Periodic Table. Instead, condensed hydrogen turned out to be transparent, like the diatomic insulating halogens in the seventh column of the Periodic Table. Wigner and Huntington predicted in 1935 that solid hydrogen at 0 K would undergo a first-order phase transition from a diatomic to a monatomic crystallographically ordered solid at {approx}25 GPa. This first-order transition would be accompanied by an insulator-metal transition. Though searched for extensively, a first-order transition from an ordered diatomic insulator to a monatomic metal is yet to be observed at pressures up to 120 and 340 GPa using x-ray diffraction and visual inspection, respectively. On the other hand, hydrogen reaches the minimum electrical conductivity of a metal at 140 GPa, 0.6 g/cm{sup 3}, and 3000 K. These conditions were achieved using a shock wave reverberating between two stiff sapphire anvils. The shock wave was generated with a two-stage light-gas gun. This temperature exceeds the calculated melting temperature …
Date: February 6, 2001
Creator: Nellis, W J
Object Type: Article
System: The UNT Digital Library
Mixing-controlled exothermic fields in explosions (open access)

Mixing-controlled exothermic fields in explosions

A theoretical model of combustion in explosions at large Reynolds, Peclet and Damkoehler numbers is described. A key feature of the model is that combustion is treated as material transformations in the Le Chatelier state plane, rather than ''heat release''. In the limit considered here, combustion is concentrated on thin exothermic sheets (boundaries between fuel and oxidizer). The products seem to expand along the sheet, thereby inducing vorticity on either side of the sheet that continues to feed the process. The results illustrate the linking between turbulence (vorticity) and exothermicity (dilatation) in the limit of fast chemistry--thereby demonstrating the controlling role that fluid dynamics plays in such problems.
Date: February 6, 2001
Creator: Kuhl, A L; Oppenheim, A K & Ferguson, R E
Object Type: Article
System: The UNT Digital Library
Rheological Studies on Pretreated Feed and Melter Feed from AW-101 and AN-107 (open access)

Rheological Studies on Pretreated Feed and Melter Feed from AW-101 and AN-107

Rheological and physical properties testing were conducted on actual AN-107 and AW-101 pretreated feed samples prior to the addition of glass formers. Analyses were repeated following the addition of glass formers. The AN-107 and AW-101 pretreated feeds were tested at the target sodium values of nominally 6, 8, and 10 M. The AW-101 melter feeds were tested at these same concentrations, while the AN-107 melter feeds were tested at 5, 6, and 8 M with respect to sodium. These data on actual waste are required to validate and qualify results obtained with simulants.
Date: February 6, 2001
Creator: Bredt, Paul R. (BATTELLE (PACIFIC NW LAB)) & Swoboda, Robert G. (BATTELLE (PACIFIC NW LAB))
Object Type: Report
System: The UNT Digital Library
Rheological Studies on Pretreated Feed and Melter Feed from AW-101 and AN-107 (open access)

Rheological Studies on Pretreated Feed and Melter Feed from AW-101 and AN-107

Rheological and physical properties testing were conducted on actual AN-107 and AW-101 pretreated feed samples prior to the addition of glass formers. Analyses were repeated following the addition of glass formers. The AN-107 and AW-101 pretreated feeds were tested at the target sodium values of nominally 6, 8, and 10 M. The AW-101 melter feeds were tested at these same concentrations, while the AN-107 melter feeds were tested at 5, 6, and 8 M with respect to sodium. These data on actual waste are required to validate and qualify results obtained with simulants.
Date: February 6, 2001
Creator: Bredt, Paul R & Swoboda, Robert G
Object Type: Report
System: The UNT Digital Library
Simulations of shock-induced mixing& combustion of an acetylene cloud in a chamber (open access)

Simulations of shock-induced mixing& combustion of an acetylene cloud in a chamber

In this paper we present numerical simulations of the interaction of a blast wave with an acetylene bubble in a closed chamber. We model the system using the inviscid Euler equations for a mixture of ideal gases. The formulation specifies the thermodynamic behavior of the system using a Chemkin interface and includes the capability to model combustion as the ambient air mixes with the acetylene. The simulations are performed using a three-dimensional adaptive mesh refinement algorithm based on a second-order Godunov integration scheme. Simulations are compared with experimental measurements for the same configuration.
Date: February 6, 2001
Creator: Bell, J B; Day, M S; Beckner, V E; Kuhl, A L; Neuwald, P & Reichenbach, H
Object Type: Article
System: The UNT Digital Library
Speech Articulator and User Gesture Measurements Using Micropower, Interferometric EM-Sensors (open access)

Speech Articulator and User Gesture Measurements Using Micropower, Interferometric EM-Sensors

Very low power, GHz frequency, ''radar-like'' sensors can measure a variety of motions produced by a human user of machine interface devices. These data can be obtained ''at a distance'' and can measure ''hidden'' structures. Measurements range from acoustic induced, 10-micron amplitude vibrations of vocal tract tissues, to few centimeter human speech articulator motions, to meter-class motions of the head, hands, or entire body. These EM sensors measure ''fringe motions'' as reflected EM waves are mixed with a local (homodyne) reference wave. These data, when processed using models of the system being measured, provide real time states of interface positions or other targets vs. time. An example is speech articulator positions vs. time in the user's body. This information appears to be useful for a surprisingly wide range of applications ranging from speech coding synthesis and recognition, speaker or object identification, noise cancellation, hand or head motions for cursor direction, and other applications.
Date: February 6, 2001
Creator: Holzrichter, J F & Ng, L C
Object Type: Article
System: The UNT Digital Library
Waste Preparation and Transport Chemistry: Results of the FY 2000 Studies (open access)

Waste Preparation and Transport Chemistry: Results of the FY 2000 Studies

Problems with pipeline plugs at Hanford have occurred throughout its tank farm system. Most cross-site transfer lines at Hanford are no longer functional due to these plugs. Waste transfers frequently led to partial line plugs, resulting in substantial amounts of water being added to the tank system in an attempt to free the lines. In response to these plugs, the Hanford tank farm developed waste acceptance criteria that a waste must pass before it can be transferred (Shekarriz et al., 1997). The criteria, which include physical properties such as viscosity, specific gravity, and percent solids, are based primarily on past operational experience. Unfortunately, the chemistry of the waste solutions was not included in the criteria even though the tank farm operators are fully aware of its importance. Pipeline plugs have also occurred during relatively short waste transfers at Hanford. In FY 2000, the effort to saltwell pump 50,000 gal of filtered waste from tank U-103 to tank SY-102 was delayed for several weeks due to a plugged pipeline. Attempts to locate the plug(s) determined that it had occurred in the 02-A flex and that other plugs were possible in each of the SY-farm flexes. Modifications such as larger flex jumpers …
Date: February 6, 2001
Creator: Hunt, R.D.
Object Type: Report
System: The UNT Digital Library
Absorption of Bound States in Hot, Dense Matter (open access)

Absorption of Bound States in Hot, Dense Matter

Preliminary experiments using a long pulse laser generated X-ray source to back-light a short pulse laser heated thin foil have been performed at the Laboratoire pour l'Utilisation des Lasers Intenses (LULI) at Ecole Polytechnique in France. In this experiment, a 2 J, 300 ps, 532 nm laser was used to create the X-ray back-lighter. The primary diagnostic was a von Hamos spectrograph coupled to a 500 fs X-ray streak camera (TREX-VHS) developed at LLNL. This diagnostic combines high collection efficiency ({approx} 10{sup -4} steradians) with fast temporal response ({approx} 500 fs), allowing resolution of extremely transient spectral variations. The TREX-VHS was used to determine the time history, intensity, and spectral content of the back-lighter. The second diagnostic, Fourier Domain Interferometry (FDI), provides information about the position of the critical density of the target and thus the expansion hydrodynamics, laying the ground work for the plasma characterization. The plasmas were determined to be moderately to strongly coupled, resulting in absorption measurements that provide insight into bound states under such conditions.
Date: March 6, 2001
Creator: Shepherd, R.; Audebert, P.; Chenais-Popovics, C.; Geindre, J. P.; Fajardo, M.; Iglesias, C. et al.
Object Type: Article
System: The UNT Digital Library
A control-theoretic formulation of the bunch train cavity interaction. (open access)

A control-theoretic formulation of the bunch train cavity interaction.

The bunch train cavity interaction is an accelerator physics problem, for which a system-theoretic model is lacking. Modal analysis has been used to characterize the system dynamics, exploiting the system's symmetry. Correspondingly, control design has been done using classical frequency-domain-based control. Several shortcomings of these methods are highlighted, all of which are remedied by a new time-domain, system-theoretic model presented herein. The new formulation is a periodic, discrete-time system, amenable to state-space control-design methods.
Date: March 6, 2001
Creator: Schwartz, C.; Haddad, H. & Nassiri, A.
Object Type: Article
System: The UNT Digital Library
Identification and Elimination of Mechanisms Leading to UV Damage of DKDP (open access)

Identification and Elimination of Mechanisms Leading to UV Damage of DKDP

This LDRD project addressed both bulk and surface damage induced by UV-laser exposure. The primary objectives were (1) to complete our understanding of the factors leading to bulk damage, including growth conditions and orientational direction, and (2) to identify mechanisms of surface damage initiation and growth leading to mitigation methods. Due to the more advanced state of knowledge in bulk damage, a greater portion of that work was completed during the one-year term of this project. Three papers were presented at the 32nd Boulder Damage Symposium on Laser-Induced Damage in Optical Materials, and the three resulting manuscripts submitted to the Proceeding are attached: An important result from this work is that it established a dependence of obscuration from bulk damage on fluence and pulse length, which is shown.
Date: March 6, 2001
Creator: Burnham, A; Runkel, M; Chase, L; Demos, S; Staggs, M & Siekhaus, W
Object Type: Report
System: The UNT Digital Library
Mapping of Enhanced Nuclear Stability in the Heaviest Elements (open access)

Mapping of Enhanced Nuclear Stability in the Heaviest Elements

Predictions of the properties of nuclides near the extreme limits of nuclear stability provide a measure of our understanding of the fundamental properties of matter and the fission process. Predictions of an ''island of stability'' of long-lived superheavy elements beyond the limits of the known nuclides date back more than 30 years; during this time, there have been many unsuccessful searches for these nuclei. During the last decade, there has been a large effort by our group and others to systematically discover and characterize the properties of the intervening unstable nuclei. Starting 10 years ago, in an on-going collaboration with Russian scientists at the Joint Institute for Nuclear Research (JINR) at Dubna, Russia, we observed the decays of previously unknown isotopes of elements 106, 108, and 110 whose properties are determined by subtleties in the nuclear structure caused by the shell effects that are predicted to result in the island of stability in the still-heavier elements. The resulting data have been successfully reproduced by the theoreticians, whose refined predictions of the decay modes and production rates of the superheavy elements have enabled us to design experiments with the sensitivity to locate these elusive nuclides.
Date: March 6, 2001
Creator: Moody, K J; Wild, J F; Stoyer, N J; Stoyer, M A; Laue, C A & Lougheed, R W
Object Type: Report
System: The UNT Digital Library
Modeling Renewable Penetration Using a Network Economic Model (open access)

Modeling Renewable Penetration Using a Network Economic Model

This paper evaluates the accuracy of a network economic modeling approach in designing energy systems having renewable and conventional generators. The network approach models the system as a network of processes such as demands, generators, markets, and resources. The model reaches a solution by exchanging prices and quantity information between the nodes of the system. This formulation is very flexible and takes very little time to build and modify models. This paper reports an experiment designing a system with photovoltaic and base and peak fossil generators. The level of PV penetration as a function of its price and the capacities of the fossil generators were determined using the network approach and using an exact, analytic approach. It is found that the two methods agree very closely in terms of the optimal capacities and are nearly identical in terms of annual system costs.
Date: March 6, 2001
Creator: Lamont, A.
Object Type: Report
System: The UNT Digital Library
A New Freeze Concentration Process for Minimum Effluent Process in Bleached Pulp (open access)

A New Freeze Concentration Process for Minimum Effluent Process in Bleached Pulp

This project researches freeze concentration as a primary volume reduction technology for bleaching plant effluents from paper-pulp mills before they are treated by expensive technologies, such as incineration, for the destruction of the adsorbable organic halogens. Previous laboratory studies show that freeze concentration has a greater than 99.5% purification efficiency for volatile, semivolatile, and nonprocess elements, or any other solute, thus producing pure ice that can be reused in the mill as water. The first section evaluates the anticipated regulatory and public pressures associated with implementing the technology; the remaining sections deal with the experimental results from a scaled-up freeze concentration process in a 100-liter pilot-plant at Tufts University. The results of laboratory scale experiments confirmed that the freeze concentration technology could be an efficient volume reduction technology for the above elements and for removing adsorbable organic hologens and or nonprocess elements from recycled water. They also provide the necessary data for designing and operating a larger pilot plant, and identify the technical problems encountered in the scale-up and the way they could be addressed in the larger scale plants. This project was originally planned to include the operation of a large pilot plant in the facilities of Swenson Process …
Date: March 6, 2001
Creator: Qian, Ru-Ying & Botsaris, Gregory D.
Object Type: Report
System: The UNT Digital Library
Novel Parallel Numerical Methods for Radiation& Neutron Transport (open access)

Novel Parallel Numerical Methods for Radiation& Neutron Transport

In many of the multiphysics simulations performed at LLNL, transport calculations can take up 30 to 50% of the total run time. If Monte Carlo methods are used, the percentage can be as high as 80%. Thus, a significant core competence in the formulation, software implementation, and solution of the numerical problems arising in transport modeling is essential to Laboratory and DOE research. In this project, we worked on developing scalable solution methods for the equations that model the transport of photons and neutrons through materials. Our goal was to reduce the transport solve time in these simulations by means of more advanced numerical methods and their parallel implementations. These methods must be scalable, that is, the time to solution must remain constant as the problem size grows and additional computer resources are used. For iterative methods, scalability requires that (1) the number of iterations to reach convergence is independent of problem size, and (2) that the computational cost grows linearly with problem size. We focused on deterministic approaches to transport, building on our earlier work in which we performed a new, detailed analysis of some existing transport methods and developed new approaches. The Boltzmann equation (the underlying equation to …
Date: March 6, 2001
Creator: Brown, P N
Object Type: Report
System: The UNT Digital Library
Observations of microstructural coarsening in micro flip-chip solder joints (open access)

Observations of microstructural coarsening in micro flip-chip solder joints

Coarsening of solder microstructures dramatically affects fatigue lifetimes. This paper presents a study of microstructural evolution due to thermal cycling and aging of small solder joints.
Date: March 6, 2001
Creator: Barney, Monica M. & Morris, John W., Jr.
Object Type: Article
System: The UNT Digital Library
Relative Advantages of Direct and Indirect Drive for an Inertial Fusion Energy Power Plant Driven by a Diode-Pumped Solid-State Laser (open access)

Relative Advantages of Direct and Indirect Drive for an Inertial Fusion Energy Power Plant Driven by a Diode-Pumped Solid-State Laser

This paper reviews our current understanding of the relative advantages of direct drive (DD) and indirect drive (ID) for a 1 GWe inertial fusion energy (IFE) power plant driven by a diode-pumped solid-state laser (DPSSL). This comparison is motivated by a recent study (1) that shows that the projected cost of electricity (COE) for DD is actually about the same as that for ID even though the target gain for DD can be much larger. We can therefore no longer assume that DD is the ultimate targeting scenario for IFE, and must begin a more rigorous comparison of these two drive options. The comparison begun here shows that ID may actually end up being preferred, but the uncertainties are still rather large.
Date: March 6, 2001
Creator: Orth, C D
Object Type: Article
System: The UNT Digital Library
Relative Advantages of Direct and Indirect Drive for an Inertial Fusion Energy Power Plant Driven by a Diode-Pumped Solid-State Laser (open access)

Relative Advantages of Direct and Indirect Drive for an Inertial Fusion Energy Power Plant Driven by a Diode-Pumped Solid-State Laser

This paper reviews our current understanding of the relative advantages of direct drive (DD) and indirect drive (ID) for a 1 GWe inertial fusion energy (IFE) power plant driven by a diode-pumped solid-state laser (DPSSL). This comparison is motivated by a recent study (1) that shows that the projected cost of electricity (COE) for DD is actually about the same as that for ID even though the target gain for DD can be much larger. We can therefore no longer assume that DD is the ultimate targeting scenario for IFE, and must begin a more rigorous comparison of these two drive options. The comparison begun here shows that ID may actually end up being preferred, but the uncertainties are still rather large.
Date: March 6, 2001
Creator: Orth, C.D.
Object Type: Article
System: The UNT Digital Library
Use of a Superconducting Tunnel Junction for X-Ray Fluorescence Spectroscopy (open access)

Use of a Superconducting Tunnel Junction for X-Ray Fluorescence Spectroscopy

A superconducting tunnel junction (STJ) in combination with a superconducting absorber of radiation may function as a highly resolving x-ray spectrometer. Electronic excitations, or quasiparticles, are created when a superconductor absorbs an x ray and are detected as an excess tunnel current through the junction. The number of quasiparticles created and the magnitude of the excess current is proportional to the energy of the absorbed x ray. This is similar to existing semiconductor-based spectrometers that measure electron-hole pairs, but with 1000 times more excitations. The energy measurement therefore can be up to 30 times more precise with a superconducting detector than with a semiconductor detector. This work describes the development and testing of an STJ spectrometer design for x-ray fluorescence applications. First, the basic principles of the STJ spectrometer are explained. This is followed by detailed simulations of the variance in the number of quasiparticles produced by absorption of an x ray. This variance is inherent in the detector and establishes an upper limit on the resolving power of the spectrometer. These simulations include effects due to the materials used in the spectrometer and to the multilayer structure of the device. Next, the spectrometer is characterized as functions of operating …
Date: March 6, 2001
Creator: Hiller, L
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Visual Sample Plan (VSP) Models and Code Verification (open access)

Visual Sample Plan (VSP) Models and Code Verification

VSP is an easy to use, visual and graphic software tool being developed to select the right number and location of environmental samples so that the results of statistical tests performed to provide input to environmental decisions have the required confidence and performance. It is a significant help for implementing the 6th and 7th steps of the Data Quality Objectives (DQO) planning process ("Specify Tolerable Limits on Decision Errors" and "Optimize the Design for Obtaining Data," respectively).
Date: March 6, 2001
Creator: Gilbert, Richard O.; Davidson, James R.; Wilson, John E. & Pulsipher, Brent A.
Object Type: Report
System: The UNT Digital Library