All-Solid-State Four-Color Laser (open access)

All-Solid-State Four-Color Laser

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The goal of this project is to develop a solid state laser that produces visible output wavelengths, including the commercially compelling blue wavelength. The basic architecture of the device consists of a single-mode optical fiber doped with Pr{sup 3+} and Yb{sup 3+} ions. When the ions are simultaneously pumped with a near infrared laser (860 nm), complex energy transfer processes involving multiple excited ions leads to population of a high-lying energy level of Pr{sup 3+}. Results include the demonstration of the existence of a photon avalanche mechanism responsible for creation of the population inversion and demonstration of the highest optical-to-optical efficiency of any up-conversion laser reported to date. A US Patent was awarded for this invention in 1998.
Date: June 3, 1999
Creator: Gosnell, T. R. & Xie, P.
Object Type: Report
System: The UNT Digital Library
Aspartame (open access)

Aspartame

This report covers the health hazards associated with Aspartame which is artificial sweetener.
Date: June 3, 1999
Creator: Porter, Donna V.
Object Type: Report
System: The UNT Digital Library
Critical comparison of 3D imaging approaches (open access)

Critical comparison of 3D imaging approaches

Currently three imaging spectrometer architectures, tunable filter, dispersive, and Fourier transform, are viable for imaging the universe in three dimensions. There are domains of greatest utility for each of these architectures. The optimum choice among the various alternative architectures is dependent on the nature of the desired observations, the maturity of the relevant technology, and the character of the backgrounds. The domain appropriate for each of the alternatives is delineated; both for instruments having ideal performance as well as for instrumentation based on currently available technology. The environment and science objectives for the Next Generation Space Telescope will be used as a specific representative case to provide a basis for comparison of the various alternatives.
Date: June 3, 1999
Creator: Bennett, C L
Object Type: Article
System: The UNT Digital Library
Design study of 45-mm bore dipole magnet for 11 to 12 tesla field (open access)

Design study of 45-mm bore dipole magnet for 11 to 12 tesla field

Two designs of 45mm bore dipole magnets are described about their magnetic characteristics. The first one has a 25mm thick collar with overall diameter of 520 mm. The other one has a 9-mm thin spacer with the overall diameter of 434 mm. Both of them have good field regions of 10{sup -4}, 28 mm wide horizontally and 24 mm wide vertically. With further adjustment of higher harmonics, the good field region can be horizontally increased to 33 mm. With the installation of a beam screen, the estimated vacuum space available for the beam operation is 33 mm wide horizontally and 22 mm wide vertically. If we assume that the total degradation of short sample data is 18.5%, the maximum central field values at quench current will be between 11.3 and 11.5 T.
Date: June 3, 1999
Creator: Moeller, Jonathan; Wake, Masayoshi & Yamada, Ryuji
Object Type: Report
System: The UNT Digital Library
Design verification and validation plan for the cold vacuum drying facility (open access)

Design verification and validation plan for the cold vacuum drying facility

The Cold Vacuum Drying Facility (CVDF) provides the required process systems, supporting equipment, and facilities needed for drying spent nuclear fuel removed from the K Basins. This document presents the both completed and planned design verification and validation activities.
Date: June 3, 1999
Creator: NISHIKAWA, L.D.
Object Type: Report
System: The UNT Digital Library
Designing a Micro-Mechanical Transistor (open access)

Designing a Micro-Mechanical Transistor

This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Micro-mechanical electronic systems are chips with moving parts. They are fabricated with the same techniques that are used to manufacture electronic chips, sharing their low cost. Micro-mechanical chips can also contain electronic components. By combining mechanical parts with electronic parts it becomes possible to process signal mechanically. To achieve designs comparable to those obtained with electronic components it is necessary to have a mechanical device that can change its behavior in response to a small input - a mechanical transistor. The work proposed will develop the design tools for these complex-shaped resonant structures using the geometrical ray technique. To overcome the limitations of geometrical ray chaos, the dynamics of the rays will be studied using the methods developed for the study of nonlinear dynamical systems. T his leads to numerical methods that execute well in parallel computer architectures, using a limited amount of memory and no inter-process communication.
Date: June 3, 1999
Creator: Mainieri, R.
Object Type: Report
System: The UNT Digital Library
Development of a Fundamental Understanding of Chemical Bonding and Electronic Structure in Spinel Compounds (open access)

Development of a Fundamental Understanding of Chemical Bonding and Electronic Structure in Spinel Compounds

This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Hundreds of ceramic compounds possess the spinel crystal structure and exhibit a remarkable variety of properties, ranging from compounds that are electrical insulators to compounds that are superconducting, or from compounds with ferri- and antiferromagnetic behavior to materials with colossal magnetoresistive characteristics. The unique crystal structure of spinel compounds is in many ways responsible for the widely varying physical properties of spinels. The objective of this project is to investigate the nature of chemical bonding, point defects, and electronic structure in compounds with the spinel crystal structure. Our goal is to understand and predict the stability of the spinel structure as a function of chemical composition, stoichiometry, and cation disorder. The consequences of cation disorder in spinel materials can be profound . The ferromagnetic characteristics of magnesioferrite, for instance, are entirely attributable to disorder on the cation sublattices. Our studies provide insight into the mechanisms of point defect formation and cation disorder and their effects on the electronic band structure and crystal structure of spinel-structure materials. Our ultimate objective is to develop a more substantive knowledge of the spinel …
Date: June 3, 1999
Creator: Sickafus, K. E.; Wills, J. M.; Chen, S. P.; Terry, J. H. Jr.; Hartmann, T. & Sheldon, R. I.
Object Type: Report
System: The UNT Digital Library
Electroweak Precision Measurements and Collider Probes of the Standard Model with Large Extra Dimensions (open access)

Electroweak Precision Measurements and Collider Probes of the Standard Model with Large Extra Dimensions

The elementary particles of the Standard Model may live in more than 3+1 dimensions. We study the consequences of large compactified dimensions on scattering and decay observables at high-energy colliders. Our analysis includes global fits to electroweak precision data, indirect tests at high-energy electron-positron colliders (LEP2 and NLC), and direct probes of the Kaluza-Klein resonances at hadron colliders (Tevatron and LHC). The present limits depend sensitively on the Higgs sector, both the mass of the Higgs boson and how many dimensions it feels. If the Higgs boson is trapped on a 3+1 dimensional wall with the fermions, large Higgs masses (up to 500 GeV) and relatively light Kaluza-Klein mass scales (less than 4 TeV) can provide a good fit to precision data. That is, a light Higgs boson is not necessary to fit the electroweak precision data, as it is in the Standard Model. If the Higgs boson propagates in higher dimensions, precision data prefer a light Higgs boson (less than 260 GeV), and a higher compactification scale (greater than 3.8 TeV). Future colliders can probe much larger scales. For example, a 1.5 TeV electron-positron linear collider can indirectly discover Kaluza-Klein excitations up to 31 TeV if 500 fb{sup {minus}1} …
Date: June 3, 1999
Creator: Rizzo, Thomas G.
Object Type: Report
System: The UNT Digital Library
Elliptic Solvers for Adaptive Mesh Refinement Grids (open access)

Elliptic Solvers for Adaptive Mesh Refinement Grids

We are developing multigrid methods that will efficiently solve elliptic problems with anisotropic and discontinuous coefficients on adaptive grids. The final product will be a library that provides for the simplified solution of such problems. This library will directly benefit the efforts of other Laboratory groups. The focus of this work is research on serial and parallel elliptic algorithms and the inclusion of our black-box multigrid techniques into this new setting. The approach applies the Los Alamos object-oriented class libraries that greatly simplify the development of serial and parallel adaptive mesh refinement applications. In the final year of this LDRD, we focused on putting the software together; in particular we completed the final AMR++ library, we wrote tutorials and manuals, and we built example applications. We implemented the Fast Adaptive Composite Grid method as the principal elliptic solver. We presented results at the Overset Grid Conference and other more AMR specific conferences. We worked on optimization of serial and parallel performance and published several papers on the details of this work. Performance remains an important issue and is the subject of continuing research work.
Date: June 3, 1999
Creator: Quinlan, D.J.; Dendy, J.E., Jr. & Shapira, Y.
Object Type: Report
System: The UNT Digital Library
Faulty assumptions for repository requirements (open access)

Faulty assumptions for repository requirements

Long term performance requirements for a geologic repository for spent nuclear fuel and high-level waste are based on assumptions concerning water use and subsequent deaths from cancer due to ingesting water contaminated with radio isotopes ten thousand years in the future. This paper argues that the assumptions underlying these requirements are faulty for a number of reasons. First, in light of the inevitable technological progress, including efficient desalination of water, over the next ten thousand years, it is inconceivable that a future society would drill for water near a repository. Second, even today we would not use water without testing its purity. Third, today many types of cancer are curable, and with the rapid progress in medical technology in general, and the prevention and treatment of cancer in particular, it is improbable that cancer caused by ingesting contaminated water will be a sign&ant killer in the far future. This paper reviews the performance requirements for geological repositories and comments on the difficulties in proving compliance in the face of inherent uncertainties. The already tiny long-term risk posed by a geologic repository is presented and contrasted with contemporary every day risks. A number of examples of technological progress, including cancer treatments, …
Date: June 3, 1999
Creator: Sutcliffe, W G
Object Type: Article
System: The UNT Digital Library
Final Report (1994 to 1996) Diagnostic of the Spatial and Velocity Distribution of Alpha Particles in Tokamak Fusion Reactor using Beat-wave Generated Lower Hybrid Wave (open access)

Final Report (1994 to 1996) Diagnostic of the Spatial and Velocity Distribution of Alpha Particles in Tokamak Fusion Reactor using Beat-wave Generated Lower Hybrid Wave

The alpha particles in a fusion reactor play a key role in the sustaining the fusion reaction. It is the heating provided by the alpha particles that help a fusion reactor operating in the ignition regime. It is, therefore, essential to understand the behavior of the alpha population both in real space and velocity space in order to design the optimal confinement device for fusion application. Moreover, the alphas represent a strong source of free energy that may generate plasma instabilities. Theoretical studies has identified the Toroidal Alfven Eigenmode (TAE) as an instability that can be excited by the alpha population in a toroidal device. Since the alpha has an energy of 3.5 MeV, a good confinement device will retain it in the interior of the plasma. Therefore, alpha measurement system need to probe the interior of a high density plasma. Due to the conducting nature of a plasma, wave with frequencies below the plasma frequency can not penetrate into the interior of the plasma where the alphas reside. This project uses a wave that can interact with the perpendicular motion of the alphas to probe its characteristics. However, this wave (the lower hybrid wave) is below the plasma frequency …
Date: June 3, 1999
Creator: Hwang, D.Q.; Horton, R.D. & Evans, R.W.
Object Type: Report
System: The UNT Digital Library
Internal Controls: Matters Related to Disbursements (open access)

Internal Controls: Matters Related to Disbursements

Correspondence issued by the General Accounting Office with an abstract that begins "Pursuant to a legislative requirement, GAO provided information on the Financial Management Service's (FMS) internal controls over federal disbursements."
Date: June 3, 1999
Creator: United States. General Accounting Office.
Object Type: Text
System: The UNT Digital Library
Iron dominated resistive magnets (open access)

Iron dominated resistive magnets

This paper starts with a review of Amperes Law and Potential Theory (Perfect Iron). It then proceeds to a discussion of Magnet Ends and on to Curved Magnets, Coil Construction, and Core Construction. It concludes with a discussion of Quality Control Methods and Examples of Recent Magnets Built.
Date: June 3, 1999
Creator: Mills, Fred E.
Object Type: Report
System: The UNT Digital Library
Kosovo: Historical Background to the Current Conflict (open access)

Kosovo: Historical Background to the Current Conflict

None
Date: June 3, 1999
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Kosovo Military Operations: Costs and Congressional Action on Funding (open access)

Kosovo Military Operations: Costs and Congressional Action on Funding

This report provides an overview of the costs and congressional action on funding of the Kosovo military operations.
Date: June 3, 1999
Creator: Daggett, Stephen
Object Type: Report
System: The UNT Digital Library
Magnetic Resonance Force Microscope Development (open access)

Magnetic Resonance Force Microscope Development

Our objectives were to develop the Magnetic Resonance Force Microscope (MRFM) into an instrument capable of scientific studies of buried structures in technologically and scientifically important electronic materials such as magnetic multilayer materials. This work resulted in the successful demonstration of MRFM-detected ferromagnetic resonance (FMR) as a microscopic characterization tool for thin magnetic films. Strong FMR spectra obtained from microscopic Co thin films (500 and 1000 angstroms thick and 40 x 200 microns in lateral extent) allowed us to observe variations in sample inhomogeneity and magnetic anisotropy field. We demonstrated lateral imaging in microscopic FMR for the first time using a novel approach employing a spatially selective local field generated by a small magnetically polarized spherical crystallite of yttrium iron garnet. These successful applications of the MRFM in materials studies provided the basis for our successful proposal to DOE/BES to employ the MRF M in studies of buried interfaces in magnetic materials.
Date: June 3, 1999
Creator: Hammel, P. C.; Zhang, Z.; Suh, B. J.; Roukes, M. L.; Midzor, M.; Wigen, P. E. et al.
Object Type: Report
System: The UNT Digital Library
Particles and Patterns in Cellular Automata (open access)

Particles and Patterns in Cellular Automata

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). Our objective has been to develop tools for studying particle interactions in a class of dynamical systems characterized by discreteness, determinism, local interaction, and an inherently parallel form of evolution. These systems can be described by cellular automata (CA) and the behavior we studied has improved our understanding of the nature of patterns generated by CAs, their ability to perform global computations, and their relationship to continuous dynamical systems. We have also developed a rule-table mathematics that enables one to custom-design CA rule tables to generate patterns of specified types, or to perform specified computational tasks.
Date: June 3, 1999
Creator: Jen, E.; Das, R. & Beasley, C.E.
Object Type: Report
System: The UNT Digital Library
Quantum Cryptography for Secure Communications to Low-Earth Orbit Satellites (open access)

Quantum Cryptography for Secure Communications to Low-Earth Orbit Satellites

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). Quantum cryptography is an emerging technology in which two parties may simultaneously generate shared, secret cryptographic key material using the transmission of quantum states of light. The security of these transmissions is based on the inviolability of the laws of quantum mechanics. An adversary can neither successfully tap the quantum transmissions, nor evade detection. Key material is built up using the transmission of a single-photon per bit. We have developed an experimental quantum cryptography system based on the transmission of non-orthogonal single-photon polarization states to generate shared key material over line-of-sight optical links. Our results provide strong evidence that cryptographic key material could be generated on demand between a ground station and a satellite (or between two satellites), allowing a satellite to be securely re-keyed on in orbit.
Date: June 3, 1999
Creator: Hughes, R. J.; Buttler, W. T.; Kwiat, P. G.; Lamoreaux, S. K.; Morgan, G. L.; Peterson, C. G. et al.
Object Type: Report
System: The UNT Digital Library
Robust Bearing Estimation for 3-Component Stations (open access)

Robust Bearing Estimation for 3-Component Stations

A robust bearing estimation process for 3-component stations has been developed and explored. The method, called SEEC for Search, Estimate, Evaluate and Correct, intelligently exploits the in- herent information in the arrival at every step of the process to achieve near-optimal results. In particular, the approach uses a consistent framework to define the optimal time-frequency windows on which to make estimates, to make the bearing estimates themselves, to construct metrics helpful in choosing the better estimates or admitting that the bearing is immeasurable, andjinally to apply bias corrections when calibration information is available to yield a single final estimate. The method was applied to a small but challenging set of events in a seismically active region. The method demonstrated remarkable utility by providing better estimates and insights than previously available. Various monitoring implications are noted fiom these findings.
Date: June 3, 1999
Creator: Claassen, John P.
Object Type: Article
System: The UNT Digital Library
Science and Paranormal Phenomena (open access)

Science and Paranormal Phenomena

In order to ground my approach to the study of paranormal phenomena, I first explain my operational approach to physics, and to the ''historical'' sciences of cosmic, biological, human, social and political evolution. I then indicate why I believe that ''paranormal phenomena'' might-but need not- fit into this framework. I endorse the need for a new theoretical framework for the investigation of this field presented by Etter and Shoup at this meeting. I close with a short discussion of Ted Bastin's contention that paranormal phenomena should be defined as contradicting physics.
Date: June 3, 1999
Creator: Noyes, H. Pierre
Object Type: Report
System: The UNT Digital Library
Self-Consistent Multiscale Theory of Internal Wave, Mean-Flow Interactions (open access)

Self-Consistent Multiscale Theory of Internal Wave, Mean-Flow Interactions

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The research reported here produced new effective ways to solve multiscale problems in nonlinear fluid dynamics, such as turbulent flow and global ocean circulation. This was accomplished by first developing new methods for averaging over random or rapidly varying phases in nonlinear systems at multiple scales. We then used these methods to derive new equations for analyzing the mean behavior of fluctuation processes coupled self consistently to nonlinear fluid dynamics. This project extends a technology base relevant to a variety of multiscale problems in fluid dynamics of interest to the Laboratory and applies this technology to those problems. The project's theoretical and mathematical developments also help advance our understanding of the scientific principles underlying the control of complex behavior in fluid dynamical systems with strong spatial and temporal internal variability.
Date: June 3, 1999
Creator: Holm, D. D.; Aceves, A.; Allen, J. S.; Alber, M.; Camassa, R.; Cendra, H. et al.
Object Type: Report
System: The UNT Digital Library
Solvation and Ionic Transport in Polymer Electrolyte Membranes (open access)

Solvation and Ionic Transport in Polymer Electrolyte Membranes

We developed a general theoretical framework to study the problem of proton solvation and transport in Nafion{reg_sign} and related materials.
Date: June 3, 1999
Creator: Zawodzinski, T.A., Jr.; Paddison, S.J.; Reagor, D. & Pratt, L.R.
Object Type: Report
System: The UNT Digital Library
Statement of work for services provided by the waste sampling and characterization facility for the effluent and environmental monitoring program - Calendar year 1999 (open access)

Statement of work for services provided by the waste sampling and characterization facility for the effluent and environmental monitoring program - Calendar year 1999

This document defines the services that the Waste Sampling and Characterization Facility (WSCF) shall provide the Environmental Compliance Program (ECP) throughout the calendar year for effluent and environmental monitoring (EEM) analysis. One of the purposes of EEM is to monitor liquid and gaseous effluents and the environment immediately around facilities that might contain radioactive and hazardous materials. Monitoring data are collected, evaluated, and reported to determine the degree of compliance with applicable federal and state regulations and permits.
Date: June 3, 1999
Creator: Diediker, L. P.
Object Type: Report
System: The UNT Digital Library
Test plan for measuring ventilation rates and combustible gas levels in RPP active catch tanks (open access)

Test plan for measuring ventilation rates and combustible gas levels in RPP active catch tanks

The purpose of this test is to provide an initial screening of combustible gas concentrations in catch tanks that currently are operated by River Protection Project (RPP). The data will be used to determine whether or not additional data will be needed for closure of the flammable gas unreviewed safety question for these facilities. This test will involve field measurements of ammonia, organic vapor, and total combustible gas levels in the headspace of the catch tanks. If combustible gas level in a tank exceeds an established threshold, gas samples will be collected in SUMMA canisters for more extensive laboratory analysis. In addition, ventilation rates of some catch tanks will be measured to evaluate removal of flammable gas by air flow through the tanks.
Date: June 3, 1999
Creator: NGUYEN, D.M.
Object Type: Report
System: The UNT Digital Library