Detection of explosive events by monitoring acoustically-induced geomagnetic perturbations (open access)

Detection of explosive events by monitoring acoustically-induced geomagnetic perturbations

The Black Thunder Coal Mine (BTCM) near Gillette, Wyoming was used as a test bed to determine the feasibility of detecting explosion-induced geomagnetic disturbances with ground-based induction magnetometers. Two magnetic observatories were fielded at distances of 50 km and 64 km geomagnetically north from the northernmost edge of BTCM. Each observatory consisted of three separate but mutually orthogonal magnetometers, Global Positioning System (GPS) timing, battery and solar power, a data acquisition and storage system, and a three-axis seismometer. Explosions with yields of 1 to 3 kT of TNT equivalent occur approximately every three weeks at BTCM. We hypothesize that explosion-induced acoustic waves propagate upward and interact collisionally with the ionosphere to produce ionospheric electron density (and concomitant current density) perturbations which act as sources for geomagnetic disturbances. These disturbances propagate through an ionospheric Alfven waveguide that we postulate to be leaky (due to the imperfectly conducting lower ionospheric boundary). Consequently, wave energy may be observed on the ground. We observed transient pulses, known as Q-bursts, with pulse widths about 0.5 s and with spectral energy dominated by the Schumann resonances. These resonances appear to be excited in the earth-ionosphere cavity by Alfven solitons that may have been generated by the …
Date: October 7, 1999
Creator: Lewis, J P; Rock, D R; Shaeffer, D L & Warshaw, S I
Object Type: Report
System: The UNT Digital Library
Mongolia wind resource assessment project (open access)

Mongolia wind resource assessment project

The development of detailed, regional wind-resource distributions and other pertinent wind resource characteristics (e.g., assessment maps and reliable estimates of seasonal, diurnal, and directional) is an important step in planning and accelerating the deployment of wind energy systems. This paper summarizes the approach and methods being used to conduct a wind energy resource assessment of Mongolia. The primary goals of this project are to develop a comprehensive wind energy resource atlas of Mongolia and to establish a wind measurement program in specific regions of Mongolia to identify prospective sites for wind energy projects and to help validate some of the wind resource estimates. The Mongolian wind resource atlas will include detailed, computerized wind power maps and other valuable wind resource characteristic information for the different regions of Mongolia.
Date: September 7, 1998
Creator: Elliott, D.; Chadraa, B. & Natsagdorj, L.
Object Type: Article
System: The UNT Digital Library
Characterization of transient gain x-ray lasers (open access)

Characterization of transient gain x-ray lasers

We have performed numerical simulations of the transient collisional excitation Ni-like Pd 4d {r_arrow} 4p J = 0 {r_arrow} 1 147 {angstrom} laser transition recently observed at Lawrence Livermore National Laboratory (LLNL). The high gain {approximately}35 cm results from the experiment are compared with detailed modeling simulations from the 1-D RADEX code in order to better understand the main physics issues affecting the measured gain and x-ray laser propagation along the plasma column. Simulations indicate that the transient gain lifetime associated with the short pulse pumping and refraction of the x-ray laser beam out of the gain region are the main detrimental effects. Gain lifetimes of {approximately}7 ps(1/e decay) are inferred from the smoothly changing gain experimental observations and are in good agreement with the simulations. Furthermore, the modeling results indicate the presence of a longer-lived but lower gain later in time associated with the transition from transient to quasi-steady state excitation.
Date: February 7, 1999
Creator: Dunn, J; Osterheld, A & Shlyaptsev, V
Object Type: Article
System: The UNT Digital Library
Transuranic separation using organophophorus extractants adsorbed onto superparamagnetic carriers. (open access)

Transuranic separation using organophophorus extractants adsorbed onto superparamagnetic carriers.

Polymeric coated ferromagnetic carriers with an absorbed layer of octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) diluted by tributyl phosphate (TBP) are being evaluated for application in the separation and the recovery of low concentrations of americium, plutonium, and uranium from nuclear waste solutions. Due to their chemical nature, these extractants selectively complex americium and plutonium contaminants onto the particles and the complexed particles can be recovered from the solution using a magnet. Physical and chemical characterization of the extractant-absorbed particles were performed by gamma and liquid scintillation counting, scanning electron microscopic (SEM) micrograph, and other physical measurements. Plutonium, americium, and uranium separations have been performed at various HNO{sub 3} and HCl concentrations. Parameters were studied to determine the limitations and capacity of the process. The status of the chemistry and application of the process to Department of Energy (DOE) remediation efforts for actinide decontamination are discussed.
Date: October 7, 1998
Creator: Nunez, L.
Object Type: Article
System: The UNT Digital Library
A procedure for diamond turning KDP crystals (open access)

A procedure for diamond turning KDP crystals

A procedure and the equipment necessary for single-point diamond flycutting (loosely referred to as diamond turning) potassium di-hydrogen phosphate (KDP) crystals are described. It is based on current KDP diamond turning activities at the Lawrence Livermore National Laboratory (LLNL), drawing upon knowledge from the Nova crystal finishing development during the 1980`s and incorporating refinements from our efforts during 1995. In addition to describing a step-by-step process for diamond turning KDP, specific discussions are included on the necessary diamond tool geometry and edge sharpness, cutting fluid, and crystal preparation, handling, cleaning, and inspection. The authors presuppose that the reader is already familiar with diamond turning practices.
Date: July 7, 1995
Creator: Montesanti, R. C. & Thompson, S. L.
Object Type: Report
System: The UNT Digital Library
Advanced Drilling through Diagnostics-White-Drilling (open access)

Advanced Drilling through Diagnostics-White-Drilling

A high-speed data link that would provide dramatically faster communication from downhole instruments to the surface and back again has the potential to revolutionize deep drilling for geothermal resources through Diagnostics-While-Drilling (DWD). Many aspects of the drilling process would significantly improve if downhole and surface data were acquired and processed in real-time at the surface, and used to guide the drilling operation. Such a closed-loop, driller-in-the-loop DWD system, would complete the loop between information and control, and greatly improve the performance of drilling systems. The main focus of this program is to demonstrate the value of real-time data for improving drilling. While high-rate transfer of down-hole data to the surface has been accomplished before, insufficient emphasis has been placed on utilization of the data to tune the drilling process to demonstrate the true merit of the concept. Consequently, there has been a lack of incentive on the part of industry to develop a simple, low-cost, effective high-speed data link. Demonstration of the benefits of DWD based on a high-speed data link will convince the drilling industry and stimulate the flow of private resources into the development of an economical high-speed data link for geothermal drilling applications. Such a downhole communication …
Date: October 7, 1999
Creator: Finger, John T.; Glowka, David Anthony; Livesay, Billy Joe; Mansure, Arthur J. & Prairie, Michael R.
Object Type: Article
System: The UNT Digital Library
Mixed direct-iterative methods for boundary integral formulations of continuum dielectric solvation models (open access)

Mixed direct-iterative methods for boundary integral formulations of continuum dielectric solvation models

This paper develops and characterizes mixed direct-iterative methods for boundary integral formulations of continuum dielectric solvation models. We give an example, the Ca{sup ++}{hor_ellipsis}Cl{sup {minus}} pair potential of mean force in aqueous solution, for which a direct solution at thermal accuracy is difficult and, thus for which mixed direct-iterative methods seem necessary to obtain the required high resolution. For the simplest such formulations, Gauss-Seidel iteration diverges in rare cases. This difficulty is analyzed by obtaining the eigenvalues and the spectral radius of the non-symmetric iteration matrix. This establishes that those divergences are due to inaccuracies of the asymptotic approximations used in evaluation of the matrix elements corresponding to accidental close encounters of boundary elements on different atomic spheres. The spectral radii are then greater than one for those diverging cases. This problem is cured by checking for boundary element pairs closer than the typical spatial extent of the boundary elements and for those cases performing an ``in-line`` Monte Carlo integration to evaluate the required matrix elements. These difficulties are not expected and have not been observed for the thoroughly coarsened equations obtained when only a direct solution is sought. Finally, we give an example application of hybrid quantum-classical methods to …
Date: August 7, 1995
Creator: Corcelli, S. A.; Kress, J. D. & Pratt, L. R.
Object Type: Article
System: The UNT Digital Library
Molecular Environmental Science and Synchrotron Radiation Facilities An Update of the 1995 DOE-Airlie Report on Molecular Environmental Science (open access)

Molecular Environmental Science and Synchrotron Radiation Facilities An Update of the 1995 DOE-Airlie Report on Molecular Environmental Science

This workshop was requested by Dr. Robert Marianelli, Director of the DOE-BES Chemical Sciences Division, to update the findings of the Workshop on Molecular Environmental Sciences (MES) held at Airlie, VA, in July 1995. The Airlie Workshop Report defined the new interdisciplinary field referred to as Molecular Environmental Science (MES), reviewed the synchrotron radiation methods used in MES research, assessed the adequacy of synchrotron radiation facilities for research in this field, and summarized the beam time requirements of MES users based on a national MES user survey. The objectives of MES research are to provide information on the chemical and physical forms (speciation), spatial distribution, and reactivity of contaminants in natural materials and man-made waste forms, and to develop a fundamental understanding of the complex molecular-scale environmental processes, both chemical and biological, that affect the stability, transformations, mobility, and toxicity of contaminant species. These objectives require parallel studies of ''real'' environmental samples, which are complicated multi-phase mixtures with chemical and physical heterogeneities, and of simplified model systems in which variables can be controlled and fundamental processes can be examined. Only by this combination of approaches can a basic understanding of environmental processes at the molecular-scale be achieved.
Date: May 7, 1999
Creator: Bargar, John R
Object Type: Report
System: The UNT Digital Library
Detection of Galactic Dark Matter by GLAST (open access)

Detection of Galactic Dark Matter by GLAST

The mysterious dark matter has been a subject of special interest to high energy physicists, astrophysicists and cosmologists for many years. According to theoretical models, it can make up a significant fraction of the mass of the Universe. One possible form of galactic dark matter, Weakly Interacting Massive Particles (WIMPs), could be detected by their annihilation into monoenergetic gamma-ray line(s). This paper will demonstrate that the Gamma-ray Large Area Space Telescope (GLAST), scheduled for launch in 2005 by NASA, will be capable of searching for these gamma-ray lines in the energy range from 20 GeV to {approx}500 GeV and will be sufficiently sensitive to test a number of models. The required instrument performance and its capability to reject backgrounds to the required levels are explicitly discussed.
Date: July 7, 1999
Creator: Bloom, Elliott D
Object Type: Report
System: The UNT Digital Library
Damage and fracture in large aperture, fused silica, vacuum spatial filter lenses (open access)

Damage and fracture in large aperture, fused silica, vacuum spatial filter lenses

Optical damage that results in large scale fracture has been observed in the large, high-fluence, fused-silica, spatial filter lenses on the Nova and Beamlet lasers. In nearly all cases damage occurs on the vacuum side of the lenses and because the vacuum side of the lens is under tensile stress this damage can lead to catastrophic crack growth if the flaw (damage) size exceeds the critical flaw size for SiO{sub 2}. The damaged 52 cm Nova lenses fracture into two and sometimes three large pieces. Although under full vacuum load at the time they fracture, the Nova lenses do not implode. Rather the authors have observed that the pieces lock together and air slowly leaks into the vacuum spatial filter housing through the lens cracks. The Beamlet lenses have a larger aspect ratio and peak tensile stress than Nova. The peak tensile stress at the center of the output surface of the Beamlet lens is 1,490 psi versus 810 psi for Nova. During a recent Beamlet high energy shot, a damage spot on the lens grew to the critical flaw size and the lens imploded. Post shot data indicate the lens probably fractured into 5 to 7 pieces, however, unlike …
Date: July 7, 1995
Creator: Campbell, J.H.; Edwards, G.J. & Marion, J.E.
Object Type: Article
System: The UNT Digital Library
Austenite Formation Kinetics During Rapid Heating in a Microalloyed Steel (open access)

Austenite Formation Kinetics During Rapid Heating in a Microalloyed Steel

The model parameters for the normalized 1054V1 material were compared to parameters previously generated for 1026 steel, and the transformation behavior was relatively consistent. Validation of the model predictions by heating into the austenite plus undissolved ferrite phase field and rapidly quenching resulted in reasonable predictions when compared to the measured volume fractions from optical metallography. The hot rolled 1054V1 material, which had a much coarser grain size and a non-equilibrium volume fraction of pearlite, had significantly different model parameters and the on heating transformation behavior of this material was less predictable with the established model. The differences in behavior is consistent with conventional wisdom that normalized micro-structure produce a more consistent response to processing, and it reinforces the need for additional work in this area.
Date: September 7, 1999
Creator: Burnett, M. E.; Dykhuzien, Ronald C.; Kelley, J. Bruce; Puskar, Joseph D. & Robino, Charles V.
Object Type: Article
System: The UNT Digital Library
Top quark physics at the Tevatron (open access)

Top quark physics at the Tevatron

The authors present the recent results and future prospects on top quark physics at the Tevatron. They describe the measurements of the top quark mass and the search for single top quark production in 1.8-TeV p{bar p} collisions. The CDF and D0 combined results yield a top quark mass of 174.3 {+-} 5.1 GeV/c{sup 2}. The upper limit at 95% C.L. of the single top production cross section is found to be 16.0 pb and 15.6 pb for the W-gluon fusion process and s-channel W* process, respectively.
Date: October 7, 1999
Creator: Kim, S.
Object Type: Article
System: The UNT Digital Library
Radon Emanation from NORM-Contaminated Pipe Scale, Soil, and Sediment at Petroleum Industry Sites (open access)

Radon Emanation from NORM-Contaminated Pipe Scale, Soil, and Sediment at Petroleum Industry Sites

This report describes a study of radon (Rn) emanation from pipe scale and soil samples contaminated with naturally occurring radioactive material (NORM). Samples were collected at petroleum production sites in Oklahoma, Michigan, Kentucky, and Illinois. For comparison, data are also presented from preliminary studies conducted at sites in Texas and Wyoming. All samples collected were analyzed for their Rn emanation fraction, defined as the fraction of 222Rn produced that enters the interconnected pore space within a medium contaminated with 226Ra before the 222Rn undergoes radioactive decay. This measure represents one of the important parameters that determine the overall Rn activity flux from any solid medium. The goal of this project was to determine whether Rn emanation from pipe scale and soil is similar to emanation from uranium mill tailings.
Date: October 7, 1999
Creator: Rood, A.S. & White, G.J.
Object Type: Report
System: The UNT Digital Library
Valley-Fill Standstones in the Kootenai Formation on the Crow Indian Reservation, South-Central Montana (open access)

Valley-Fill Standstones in the Kootenai Formation on the Crow Indian Reservation, South-Central Montana

Subsurface data is being collected, organized, and a digital database is being prepared. An ACCESS database and PC-Arcview if being used to manage and interpret the data. Well data and base map have been successfully imported to Arcview and customized. All of the four 30 feet by 60 feet geologic surface geologic quadrangles have been scanned to produce a digital surface data base for the Crow Reservation. Field investigations inventoried for the presence of valley-fill deposits. These appear to represent at least a four major westward-trending valley systems.
Date: January 7, 1998
Creator: Lopez, David A.
Object Type: Report
System: The UNT Digital Library
Parasitic pencil beams caused by lens reflections in laser amplifier chains (open access)

Parasitic pencil beams caused by lens reflections in laser amplifier chains

Reflections from lens surfaces create parasitic beams that can damage optics in high-powered laser systems. These parasitic beams are low in energy initially, because of the low reflectivity of antireflection (AR) coated lens surfaces and because they are clipped by spatial filter pinholes, but subsequent amplification can raise them to damage fluence levels. Also, some of the pencil beams in multipass laser systems become pre-pulses at the output by by-pass one of more of the passes, arriving at the output ahead of the main pulse in time. They are insidious because pencil beams that are not initially a problem can become so due to a slow degradation of the AR coatings. Both the Nova and Beamlet laser systems at LLNL have had optics damaged by pencil beams. The best solution for pencil beams is to tip the lenses far enough to eliminate them altogether. This will be the approach taken for the National Ignition Facility (NIF).
Date: July 7, 1995
Creator: Murray, J. E.; Van Wonterghem, B. & Seppala, L.
Object Type: Article
System: The UNT Digital Library
Techniques for in Situ HVEM Mechanical Deformation of Nanostructural Materials (open access)

Techniques for in Situ HVEM Mechanical Deformation of Nanostructural Materials

We have developed two in-situ HVEM techniques which allow us to begin fundamental investigations into the mechanisms of deformation and fracture in nonstructured materials. A procedure for the observation of tensile deformation and failure in multilayers materials in cross-section is given and also the development of an in-situ HVEM nanoindentor of surfaces and films on surfaces in cross-section.
Date: August 7, 1995
Creator: Wall, M. A.; Barbee, T. W., Jr. & Dahmen, U.
Object Type: Article
System: The UNT Digital Library
Promoting Behavior-Based Energy Efficiency in Military Housing (open access)

Promoting Behavior-Based Energy Efficiency in Military Housing

The U.S. Department of Energy's Federal Energy Management Program (FEMP) helps agencies reduce the cost of doing business through energy efficiency, water conservation, and the use of solar and other renewable energy. As a large energy user, the U.S. military has been one of the government sectors of focus. Several military installations have shown substantial energy savings in past years. Most of these efficiency projects, however, have focused primarily on physical upgrades, technologies, and purchasing habits. Furthermost projects have focused on administrative and operational areas of energy use. Military residential housing, in particular, has received little formal attention for energy efficiency involving behaviors of the residents themselves. Behavior-based change is a challenging, but potentially fruitful area for energy conservation programs. However, behavioral change involves links with values, social networks and organizations, and new ways of thinking about living patterns. This handbook attempts to fill a gap by offering guidance for promoting such efforts.
Date: September 7, 1999
Creator: McMakin, Andrea H.; Lundgren, Regina E. & Malone, Elizabeth L.
Object Type: Report
System: The UNT Digital Library
Neutrino masses and sneutrino mixing in R-parity violating supersymmetry (open access)

Neutrino masses and sneutrino mixing in R-parity violating supersymmetry

R-parity-violating supersymmetry with a conserved baryon number $B$ provides a framework for particle physics with lepton number ($L$) violating interactions. Two important probes of the $L$-violating physics are neutrino masses and sneutrino-antisneutrino mass-splittings. We evaluate these quantities in the context of the most general CP-conserving, R-parity-violating $B$-conserving extension of the minimal supersymmetric standard model. In generic three-generation models, three sneutrino-antisneutrino mass splittings are generated at tree-level. In contrast, only one neutrino mass is generated at tree-level; the other two neutrinos acquire masses at one-loop. In many models, the dominant contribution to the radiative neutrino masses is induced by the non-zero sneutrino-antisneutrino mass splitting.
Date: June 7, 1999
Creator: Grossman, yuval
Object Type: Report
System: The UNT Digital Library
Photorefractivity in liquid crystals doped with a soluble conjugated polymer. (open access)

Photorefractivity in liquid crystals doped with a soluble conjugated polymer.

Photoconductive polymers are doped into liquid crystals to create a new mechanism for space-charge field formation in photorefractive liquid crystal composites. The composites contain poly(2,5-bis(2{prime}-ethylhexyloxy)-1,4-phenylenevinylene) (BEH-PPV) and the electron acceptor N,N{prime}-dioctyl-1,4:5,8-naphthalenediimide, NI. Using asymmetric energy transfer (beam coupling) measurements that are diagnostic for the photorefractive effect, the direction of beam coupling as a function of grating fringe spacing inverts at a spacing of 5.5 {micro}m. We show that the inversion is due to a change in the dominant mechanism for space-charge field formation. At small fringe spacings, the space-charge field is formed by ion diffusion in which the photogenerated anion is the more mobile species. At larger fringe spacings, the polarity of the space charge field inverts due to dominance of a charge transport mechanism in which photogenerated holes are the most mobile species due to hole migration along the BEH-PPV chains coupled with interchain hole hopping. Control experiments are presented, which use composites that can access only one of the two charge transport mechanisms. The results show that charge migration over long distances leading to enhanced photorefractive effects can be obtained using conjugated polymers dissolved in liquid crystals.
Date: July 7, 1999
Creator: Niemczyk, M. P.; Svec, W. A.; Wasielewski, M. R. & Wiederrecht, G. P.
Object Type: Article
System: The UNT Digital Library
Hydrological Methods can Separate Cesium from Nuclear Waste Saltcake (open access)

Hydrological Methods can Separate Cesium from Nuclear Waste Saltcake

Interstitial Fluid Displacement (IFD) is a new and novel method for separating cesium from saltcake waste. Hydrologic modeling of liquid flow through porous saltcake suggests that the cesium, potassium and sodium hydroxide can be separated at high recovery and low volume using IFD.
Date: October 7, 1999
Creator: Brooke, J.N.
Object Type: Article
System: The UNT Digital Library
Status report on method and results for new discriminants and combinations of discriminants for different ranges (open access)

Status report on method and results for new discriminants and combinations of discriminants for different ranges

A number of discriminants have been developed for seismic monitoring. These include the Ms-mb discriminant which measures differences in surface and body wave magnitudes (e.g., Marshall and Basham, 1972), short period P to S wave amplitude ratio discriminants (e.g., Blandford, 1981) and spectral ratios discriminants (e.g., Murphy and Bennett, 1982). Unfortunately, existing discrimination capabilities are insufficient to meet the needs that will be required by a comprehensive test ban treaty (CTBT). Of particular concern are limitations of current capabilities for discriminating small magnitude (mb<4) seismic events such as earthquakes, mining explosions, and mining related seismicity (rockbursts and collapse events) from small magnitude nuclear explosions (both coupled and decoupled). In this report, we summarize our work on the development of new methods for discriminating such small magnitude events.
Date: April 7, 1995
Creator: Goldstein, P.
Object Type: Report
System: The UNT Digital Library
Ten years of sourcery at CAMS/LLNL - evolution of a Cs ion source (open access)

Ten years of sourcery at CAMS/LLNL - evolution of a Cs ion source

The present performance and status of the LLNL AMS ion source and the rationale for the series of changes which led to the present design are discussed.
Date: October 7, 1999
Creator: Roberts, M & Southon, J
Object Type: Article
System: The UNT Digital Library
Imprinted spiral structures as neutron polarizers. (open access)

Imprinted spiral structures as neutron polarizers.

Neutron diffraction from magnetic spiral structures is governed by strong selection rules for the polarization of the outgoing beam. When the sample is entirely of one chirality--for instance a right handed spiral--the neutrons diffracted by some Bragg reflections are fully polarized. While the scattering theory has been formulated long ago, attempts to controllably modify the population of left handed and right handed spiral domains in natural magnetic structures (which for instance occur in some rare earth metals) have been largely unsuccessful. In contrast, we have been able to imprint helical magnetic structures in La/Fe multilayers (each layer approximately 30 {angstrom} thick) simply by rotating the growing sample in a weak external field (30e). A first estimate is given of the efficiency of these multilayers as polarizers of neutron beams.
Date: October 7, 1998
Creator: Lohstroh, W.
Object Type: Article
System: The UNT Digital Library
Energy R and D in the Netherlands (open access)

Energy R and D in the Netherlands

This report documents trends in R and D and in particular (public) energy R and D in the Netherlands. Besides quantitative information on R and D and energy R and D, the report gives an impression of changes in science and technology policy, energy policy and changes in energy research priorities (both organizational and financial). In the Netherlands, 2.09% of GDP (or $6.7 billion) was invested in R and D activities in 1995. The private sector financed 46% of all R and D in that year. A small but significant fraction (9.3%) of the research performed in the Netherlands is financed by foreign public and private sector entities. Energy R and D has been identified by the national Strategic Foresight Activity as an important area of R and D for government support in the future. This is due in part to the overall decline in public support for energy R and D that occurred from 1985 to 1995. However, recent concern over climate change and energy policy has resulted in increased budgets for energy R and D. Recent policy documents (e.g., the Memorandum on Energy R and D in April 1998) and initiatives (e.g., a recent university energy R and …
Date: September 7, 1999
Creator: Luiten, EEM; Dooley, JJ & Blok, K
Object Type: Report
System: The UNT Digital Library