States

Nonlinear harmonic generation and proposed experimental verification in SASE FELs. (open access)

Nonlinear harmonic generation and proposed experimental verification in SASE FELs.

Recently, a 3D, polychromatic, nonlinear simulation code was developed to study the growth of nonlinear harmonics in self-amplified spontaneous emission (SASE) free-electron lasers (FELs). The simulation was applied to the parameters for each stage of the Advanced Photon Source (APS) SASE FEL, intended for operation in the visible, UV, and short UV wavelength regimes, respectively, to study the presence of nonlinear harmonic generation. Significant nonlinear harmonic growth is seen. Here, a discussion of the code development, the APS SASE FEL, the simulations and results, and, finally, the proposed experimental procedure for verification of such nonlinear harmonic generation at the APS SASE FEL will be given.
Date: August 24, 1999
Creator: Biedron, S. G.; Freund, H. P. & Milton, S. V.
Object Type: Article
System: The UNT Digital Library
Decay out of the yrast superdeformed band in {sup 191}Hg. (open access)

Decay out of the yrast superdeformed band in {sup 191}Hg.

The excitation energies and spins of the yrast superdeformed band in {sup 191}Hg have been determined by analyzing the quasicontinuum spectrum connecting the superdeformed and normal-deformed states. The results from this analysis, combined with that given by one-step decay lines, give confident assignments of the spins and energies of the yrast superdeformed band in {sup 191}Hg.
Date: March 24, 1999
Creator: Sien, S.; Reiter, P.; Khoo, T.; Lauritsen, T.; Carpenter, M. P.; Ahmad, I. et al.
Object Type: Article
System: The UNT Digital Library
Revision of ASCE 4 (open access)

Revision of ASCE 4

The original version of ASCE Standard 4, ``Seismic Analysis of Safety-Related Nuclear Structures`` was published in September 1986. It is ASCE policy to update its standards on a five year interval and the Working Group on Seismic Analysis of Safety Related Nuclear Structures was reconvened to formulate the revisions. The goal in updating the standard is to make sure that it is still relevant and that it incorporates the state of the practice in seismic engineering or, in some cases, where it has been demonstrated that state-of-the-art improvements need to be made to standard practice; new improvements are included. The contents of the new standard cover the same areas as the original version, with some additions. The contents are as follows: Input - response spectra and time histories; modeling of structures; analysis of structures; soil-structure interaction; input for subsystem analysis; special structures - buried pipes and conduits, earth-retaining walls, above-ground vertical tanks, raceways, and base-isolated structures; and an appendix providing seismic probabilistic risk assessment and margin assessment.
Date: January 24, 1995
Creator: Nelson, T. A.; Murray, R. C. & Short, S. A.
Object Type: Article
System: The UNT Digital Library
Material accountancy measurement techniques in dry-powdered processing of nuclear spent fuels. (open access)

Material accountancy measurement techniques in dry-powdered processing of nuclear spent fuels.

The paper addresses the development of inductively coupled plasma-mass spectrometry (ICPMS), thermal ionization-mass spectrometry (TIMS), alpha-spectrometry, and gamma spectrometry techniques for in-line analysis of highly irradiated (18 to 64 GWD/T) PWR spent fuels in a dry-powdered processing cycle. The dry-powdered technique for direct elemental and isotopic accountancy assay measurements was implemented without the need for separation of the plutonium, uranium and fission product elements in the bulk powdered process. The analyses allow the determination of fuel burn-up based on the isotopic composition of neodymium and/or cesium. An objective of the program is to develop the ICPMS method for direct fissile nuclear materials accountancy in the dry-powdered processing of spent fuel. The ICPMS measurement system may be applied to the KAERI DUPIC (direct use of spent PWR fuel in CANDU reactors) experiment, and in a near-real-time mode for international safeguards verification and non-proliferation policy concerns.
Date: March 24, 1999
Creator: Wolf, S. F.
Object Type: Article
System: The UNT Digital Library
324 Facility B-cell quality process plan (open access)

324 Facility B-cell quality process plan

Quality Process Plan for the Restart of Cell Hot-Work. Addition of Table 5B.
Date: November 24, 1998
Creator: RIDDELLE, J.G.
Object Type: Report
System: The UNT Digital Library
Double pulse experiment with a velvet cathode on the ATA injector (open access)

Double pulse experiment with a velvet cathode on the ATA injector

Double pulse transport experiments were conducted on the front end of the ATA accelerator to obtain data on the capability of a velvet cloth cathode to produce two successive pulses. Pulses of approximately 3 kA were extracted from the cathode with interpulse spacings varying from 150 ns to 2.8 {micro}s using an anode-cathode voltage of about 1 MV. Analysis of the current and voltage waveform data from the injector indicate that the effects of cathode plasma on the second pulse of a two-pulse burst is minimal.
Date: April 24, 1995
Creator: Westenskow, G.; Caporaso, G.; Chen, Y.; Houck, T. & Sampayan, S.
Object Type: Report
System: The UNT Digital Library
Estimating Attributes of Nuclear Weapon and Other Fissile Material Configuration Using Features Of Nuclear Materials Identification Signatures (open access)

Estimating Attributes of Nuclear Weapon and Other Fissile Material Configuration Using Features Of Nuclear Materials Identification Signatures

This brief describes a strategy that, when implemented, will allow the attributes, i.e., the physical properties, of nuclear weapon and other configurations of fissile material to be estimated from Nuclear Material Identification System (NMIS) signatures for arms control, treaty verification, and transparency purposes. Attributes are estimated by condensing measured NMIS signatures into ''features'' that approximately represent physical characteristics of the measurement such as gamma-ray transmission, induced fission, etc. The features are obtained from NMIS signatures to estimate quantities related to gamma and neutron transmission through the inspected item and gamma and neutron scattering and production via induced fission within the inspected item. Multivariate, i.e., multiple-feature, linear models have been successfully employed to estimate attributes, and multivariate nonlinear models are currently under investigation. Attributes estimated employing this strategy can then be examined to test the supposition that the inspected item is in fact a nuclear weapon.
Date: August 24, 1999
Creator: Mattingly, J. K.; Mihalczo, J. T.; Mullens, J. A.; Perez, R. B. & Valentine, T. E.
Object Type: Report
System: The UNT Digital Library
The DOE2000 materials microcharacterization collaboratory. (open access)

The DOE2000 materials microcharacterization collaboratory.

The Materials Microcharacterization Collaborator (MMC) was created last year as a pilot project within the US Department of Energy's DOE2000 program [1]. The DOE2000 program has, as its main goals, to develop improved capabilities for solving DOE's complex scientific problems, to increase DOE's R and D productivity and efficiency, and to enhance the access of R and D partners to DOE resources. One of the strategies to meet these goals is the establishment of national collaboratories to provide access via the Internet to unique or expensive DOE research facilities and to expertise for remote collaboration, experimentation, production, software development, modeling, and measurement. In addition, collaboratories will benefit researchers by providing tools for video conferencing, shared data-viewing, and collaborative analysis. Cooperative pilots projects, jointly funded by DOE2000 and a scientific program area, are expected to lead to significant scientific achievements by developing new capabilities and increasing the efficiency of doing the work (e.g., by reducing travel, increasing communication, and promoting the sharing of data among formerly disparate research groups). The MMC project unites four DOE BES electron microscopy user centers located at ANL, LBNL, ORNL and the University of Illinois with the DOE EE center located at ORNL. Also included in …
Date: April 24, 1998
Creator: Voelkl, E.
Object Type: Article
System: The UNT Digital Library
Dynamics of gas-filled hohlraums (open access)

Dynamics of gas-filled hohlraums

In order to prevent high-Z plasma from filling in the hohlraum in indirect drive experiments, a low-Z material, or tamper is introduced into the hohlraum. This material, when fully ionized is typically less than one-tenth of the critical density for the laser light used to illuminate the hohlraum. This tamper absorbs little of the laser light, thus allowing most of the laser energy to be absorbed in the high-Z material. However, the pressure associated with this tamper is sufficient to keep the hohlraum wall material from moving a significant distance into the interior of the hohlraum. In this paper the authors discuss measurements of the motion of the interface between the tamper and the high-Z hohlraum material. They also present measurements of the effect the tamper has on the hohlraum temperature.
Date: April 24, 1995
Creator: Orzechowski, T.J.; Kauffman, R.L. & Kirkwood, R.K.
Object Type: Article
System: The UNT Digital Library
Ford Taurus Ethanol-Fueled Sedan (open access)

Ford Taurus Ethanol-Fueled Sedan

The U.S. Department of Energy (DOE) is encouraging the use of alternative fuels and alternative fuel vehicles (AFVs). To support this activity, DOE has directed the National Renewable Energy Laboratory (NREL) to conduct projects to evaluate the performance and acceptability of light-duty AFVs. In this study, we tested a pair of 1998 Ford Tauruses: one E85 (85% gasoline/15% ethanol) model (which was tested on both E85 and gasoline) and a gasoline model as closely matched as possible. Each vehicle was run through a series of tests to evaluate acceleration, fuel economy, braking, and cold-start capabilities, as well as more subjective performance indicators such as handling, climate control, and noise.
Date: June 24, 1999
Creator: Eudy, L.
Object Type: Book
System: The UNT Digital Library
Crystallization pathway in the bulk metallic glass Zr{sub 41.2}Ti{sub 13.8}Cu{sub 12.5}Ni{sub 10}Be{sub 22.5}. (open access)

Crystallization pathway in the bulk metallic glass Zr{sub 41.2}Ti{sub 13.8}Cu{sub 12.5}Ni{sub 10}Be{sub 22.5}.

A new family of multicomponent metallic alloys exhibits an excellent glass forming ability at moderate cooling rates of about 10K/s and a wide supercooled liquid region. These glasses are eutectic or nearly eutectic, thus far away from the compositions of competing crystalline phases. The nucleation of crystals from the homogeneous amorphous phase requires large thermally activated composition fluctuations for which the time scale is relatively long, even in the supercooled liquid. In the Zr{sub 41.2}Ti{sub 13.8}Cu{sub 12.5}Ni{sub 10}Be{sub 22.5} alloy therefore a different pathway to crystallization is observed. The initially homogeneous alloy separates into two amorphous phases. In the decomposed regions, crystallization probability increases and finally polymorphic crystallization occurs. The evolution of decomposition and succeeding primary crystallization in the bulk amorphous Zr{sub 41.2}Ti{sub 13.8}Cu{sub 12.5}Ni{sub 10}Be{sub 22.5}, alloy have been studied by small angle neutron. Samples annealed isothermally in the supercooled liquid and in the solid state exhibit interference peaks indicating quasiperiodic inhomogeneities in the scattering length density. The related wavelengths increase with temperature according to the linear Cahn-Hilliard theory for spinodal decomposition. Also the time evolution of the interference peaks in the early stages is consistent with this theory. At later stages, X-ray diffraction and transmission electron microscopy investigations …
Date: June 24, 1997
Creator: Geyer, U.; Johnson, W. L.; Schneider, S. & Thiyagarajan, P.
Object Type: Article
System: The UNT Digital Library
Medical and Health Divisions quarterly report, January, February, March 1948 (open access)

Medical and Health Divisions quarterly report, January, February, March 1948

This quarterly progress report describes four programs namely (1) The Metabolic Properties of Plutonium and Allied Materials (2) Biological studies of radiation effects, (3) Biological effects of radiation from external and internal sources, and (4) Health Physics and Chemistry. Progress for each program has been separately indexed and abstracted for the database.
Date: May 24, 1948
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Measurements of Z{sup 0} to Heavy-quark couplings at SLD (open access)

Measurements of Z{sup 0} to Heavy-quark couplings at SLD

We present measurements of Z{sup 0} to heavy-quark coupling electroweak parameters, R{sub b}, R{sub c}, and parity-violation parameter A{sub c}, from SLD. The measurements are based on approximately 550k hadronic Z{sup 0} events collected in 1993-98. Obtained preliminary results of R{sub b} and R{sub c} measurements are R{sub b} = 0.2159 {+-} 0.0014 {+-} 0.0014 and R{sub c} = 0.1685 {+-} 0.0047 {+-} 0.0043. In the A{sub c} measurement, we use four methods to determine the initial-quark charge: combined Kaon charge and Vertex charge, lepton, exclusively reconstructed D*, D-mesons, and a new method using inclusive soft-pion from D*. The preliminary results of these four methods were combined to give A{sub c} = 0.634 {+-} 0.027.
Date: May 24, 1999
Creator: Iwasaki, Masako
Object Type: Report
System: The UNT Digital Library
Spent fuel test project, Climax granitic stock, Nevada Test Site (open access)

Spent fuel test project, Climax granitic stock, Nevada Test Site

The Spent Fuel Test-Climax (SFT-C) is a test of dry geologic storage of spent nuclear reactor fuel. The SFT-C is located at a depth of 420 m in the Climax granitic stock at the Nevada Test Site. Eleven canisters of spent commercial PWR fuel assemblies are to be stored for 3 to 5 years. Additional heat is supplied by electrical heaters, and more than 800 channels of technical information are being recorded. The measurements include rock temperature, rock displacement and stress, joint motion, and monitoring of the ventilation air volume, temperature, and dewpoint.
Date: October 24, 1980
Creator: Ramspott, L.D.
Object Type: Article
System: The UNT Digital Library
Fluor Daniel Hanford contract standards/requirements identification document (open access)

Fluor Daniel Hanford contract standards/requirements identification document

This document, the Standards/Requirements Identification Document (S/RID) for the Fluor Daniel Hanford Contract, represents the necessary and sufficient requirements to provide an adequate level of protection of the worker, public health and safety, and the environment.
Date: April 24, 1997
Creator: Bennett, G.L.
Object Type: Report
System: The UNT Digital Library
Advanced millimeter wave chemical sensor. (open access)

Advanced millimeter wave chemical sensor.

This paper discusses the development of an advanced millimeter-wave (mm-wave) chemical sensor and its applications for environmental monitoring and arms control treaty verification. The purpose of this work is to investigate the use of fingerprint-type molecular rotational signatures in the mm-wave spectrum to sense airborne chemicals. The mm-wave spectrum to sense airborne chemicals. The mm-wave sensor, operating in the frequency range of 220-300 GHz, can work under all weather conditions and in smoky and dusty environments. The basic configuration of the mm-wave sensor is a monostatic swept-frequency radar consisting of a mm-wave sweeper, a hot-electron-bolometer or Schottky barrier detector, and a trihedral reflector. The chemical plume to be detected is situated between the transmitter/detector and the reflector. Millimeter-wave absorption spectra of chemicals in the plume are determined by measuring the swept-frequency radar return signals with and without the plume in the beam path. The problem of pressure broadening, which hampered open-path spectroscopy in the past, has been mitigated in this work by designing a fast sweeping source over a broad frequency range. The heart of the system is a Russian backward-wave oscillator (BWO) tube that can be tuned over 220-350 GHz. Using the Russian BWO tube, a mm-wave radar system …
Date: March 24, 1999
Creator: Gopalsami, N.
Object Type: Article
System: The UNT Digital Library
Ford F250 Dedicated CNG Pickup (open access)

Ford F250 Dedicated CNG Pickup

The U.S. Department of Energy (DOE) is encouraging the use of alternative fuels and alternative fuel vehicles (AFVs). To support this activity, DOE has directed the National Renewable Energy Laboratory (NREL) to conduct projects to evaluate the performance and acceptability of light-duty AFVs. In this study, we tested a pair of 1998 Ford F-250 pickups: one dedicated compressed natural gas (CNG) model and a gasoline model as closely matched as possible. Each vehicle was run through a series of tests to evaluate acceleration, fuel economy, braking, and cold-start capabilities, as well as more subjective performance indicators such as handling, climate control, and noise.
Date: June 24, 1999
Creator: Eudy, L.
Object Type: Book
System: The UNT Digital Library
Fuzzy Logic Connectivity in Semiconductor Defect Clustering (open access)

Fuzzy Logic Connectivity in Semiconductor Defect Clustering

In joining defects on semiconductor wafer maps into clusters, it is common for defects caused by different sources to overlap. Simple morphological image processing tends to either join too many unrelated defects together or not enough together. Expert semiconductor fabrication engineers have demonstrated that they can easily group clusters of defects from a common manufacturing problem source into a single signature. Capturing this thought process is ideally suited for fuzzy logic. A system of rules was developed to join disconnected clusters based on properties such as elongation, orientation, and distance. The clusters are evaluated on a pair-wise basis using the fuzzy rules and are joined or not joined based on a defuzzification and threshold. The system continuously re-evaluates the clusters under consideration as their fuzzy memberships change with each joining action. The fuzzy membership functions for each pair-wise feature, the techniques used to measure the features, and methods for improving the speed of the system are all developed. Examples of the process are shown using real-world semiconductor wafer maps obtained from chip manufacturers. The algorithm is utilized in the Spatial Signature Analyzer (SSA) software, a joint development project between Oak Ridge National Lab (ORNL) and SEMATECH.
Date: January 24, 1999
Creator: Gleason, S.S.; Kamowski, T.P. & Tobin, K.W.
Object Type: Article
System: The UNT Digital Library
Ceramic Processing (open access)

Ceramic Processing

Ceramics represent a unique class of materials that are distinguished from common metals and plastics by their: (1) high hardness, stiffness, and good wear properties (i.e., abrasion resistance); (2) ability to withstand high temperatures (i.e., refractoriness); (3) chemical durability; and (4) electrical properties that allow them to be electrical insulators, semiconductors, or ionic conductors. Ceramics can be broken down into two general categories, traditional and advanced ceramics. Traditional ceramics include common household products such as clay pots, tiles, pipe, and bricks, porcelain china, sinks, and electrical insulators, and thermally insulating refractory bricks for ovens and fireplaces. Advanced ceramics, also referred to as ''high-tech'' ceramics, include products such as spark plug bodies, piston rings, catalyst supports, and water pump seals for automobiles, thermally insulating tiles for the space shuttle, sodium vapor lamp tubes in streetlights, and the capacitors, resistors, transducers, and varistors in the solid-state electronics we use daily. The major differences between traditional and advanced ceramics are in the processing tolerances and cost. Traditional ceramics are manufactured with inexpensive raw materials, are relatively tolerant of minor process deviations, and are relatively inexpensive. Advanced ceramics are typically made with more refined raw materials and processing to optimize a given property or …
Date: November 24, 1999
Creator: EWSUK,KEVIN G.
Object Type: Article
System: The UNT Digital Library
Determination of operating limits for radionuclides for a proposed landfill at Paducah Gaseous Diffusion Plant (open access)

Determination of operating limits for radionuclides for a proposed landfill at Paducah Gaseous Diffusion Plant

The operating limits for radionuclides in sanitary and industrial wastes were determined for a proposed landfill at the Paducah Gaseous Diffusion Plant (PGDP), Kentucky. These limits, which may be very small but nonzero, are not mandated by law or regulation but are needed for rational operation. The approach was based on analyses of the potential contamination of groundwater at the plant boundary and the potential exposure to radioactivity of an intruder at the landfill after closure. The groundwater analysis includes (1) a source model describing the disposal of waste and the release of radionuclides from waste to the groundwater, (2) site-specific groundwater flow and contaminant transport calculations, and (3) calculations of operating limits from the dose limit and conversion factors. The intruder analysis includes pathways through ingestion of contaminated vegetables and soil, external exposure to contaminated soil, and inhalation of suspended activity from contaminated soil particles. In both analyses, a limit on annual effective dose equivalent of 4 mrem (0.04 mSv) was adopted. The intended application of the results is to refine the radiological monitoring standards employed by the PGDP Health Physics personnel to determine what constitutes radioactive wastes, with concurrence of the Commonwealth of Kentucky.
Date: May 24, 1994
Creator: Wang, J. C.; Lee, D. W.; Ketelle, R. H.; Lee, R. R. & Kocher, D. C.
Object Type: Article
System: The UNT Digital Library
Lifetime measurements and dipole transition rates for superdeformed states in {sup 190}Hg. (open access)

Lifetime measurements and dipole transition rates for superdeformed states in {sup 190}Hg.

The Doppler-shift attenuation method was used to measure life-times of superdeformed (SD) states for both the yrast and the first excited superdeformed band of {sup 190}Hg. Intrinsic quadruple moments Q{sub 0} were extracted. For the first time, the dipole transition rates have been extracted for the inter-band transitions which connect the excited SD band to the yrast states in the second minimum. The results support the interpretation of the excited SD band as a rotational band built on an octupole vibration.
Date: March 24, 1999
Creator: Amro, H.
Object Type: Article
System: The UNT Digital Library
Integrated safety management approach for the approval and conduct of subcritical experiments (SCE) for the science-based Nuclear Stockpile Stewardship Program (open access)

Integrated safety management approach for the approval and conduct of subcritical experiments (SCE) for the science-based Nuclear Stockpile Stewardship Program

None
Date: April 24, 1997
Creator: Nelson, C. A., LLNL
Object Type: Article
System: The UNT Digital Library
Evaluation of photoneutron production at high energy LINACS (open access)

Evaluation of photoneutron production at high energy LINACS

This report describes an estimate of neutron production at a 9 MeV LINAC, and the potential for photoactivation of materials present at the LINAC facility. It was found that only isotopes of U, W, Ta, and Pb had daughters whose activities might be measurable. The LINAC was found to be capable of producing in the neighborhood of 10{sup 10} neutrons/second from these heavy metals, and that subsequent neutron activation might be more of a concern. Monte Carlo simulation of neutron transport and capture in the concrete and steel found in the LINAC vault indicates that {sup 55}Fe may be produced in measurable quantities.
Date: April 24, 1995
Creator: Bell, Z.W.
Object Type: Report
System: The UNT Digital Library
Newton-Krylov-Schwarz methods for aerodynamics problems : compressible and incompressible flows on unstructured grids. (open access)

Newton-Krylov-Schwarz methods for aerodynamics problems : compressible and incompressible flows on unstructured grids.

We review and extend to the compressible regime an earlier parallelization of an implicit incompressible unstructured Euler code [9], and solve for flow over an M6 wing in subsonic, transonic, and supersonic regimes. While the parallelization philosophy of the compressible case is identical to the incompressible, we focus here on the nonlinear and linear convergence rates, which vary in different physical regimes, and on comparing the performance of currently important computational platforms. Multiple-scale problems should be marched out at desired accuracy limits, and not held hostage to often more stringent explicit stability limits. In the context of inviscid aerodynamics, this means evolving transient computations on the scale of the convective transit time, rather than the acoustic transit time, or solving steady-state problems with local CFL numbers approaching infinity. Whether time-accurate or steady, we employ Newton's method on each (pseudo-) timestep. The coupling of analysis with design in aerodynamic practice is another motivation for implicitness. Design processes that make use of sensitivity derivatives and the Hessian matrix require operations with the Jacobian matrix of the state constraints (i.e., of the governing PDE system); if the Jacobian is available for design, it may be employed with advantage in a nonlinearly implicit analysis, …
Date: February 24, 1999
Creator: Kaushik, D. K.; Keyes, D. E. & Smith, B. F.
Object Type: Article
System: The UNT Digital Library