Automated damage test facilities for materials development and production optic quality assurance at Lawrence Livermore National Laboratory (open access)

Automated damage test facilities for materials development and production optic quality assurance at Lawrence Livermore National Laboratory

The Laser Program at LLNL has developed automated facilities for damage testing optics up to 1 meter in diameter. The systems were developed to characterize the statistical distribution of localized damage performance across large-aperture National Ignition Facility optics. Full aperture testing is a key component of the quality assurance program for several of the optical components. The primary damage testing methods used are R:1 mapping and raster scanning. Automation of these test methods was required to meet the optics manufacturing schedule. The automated activities include control and diagnosis of the damage-test laser beam as well as detection and characterization of damage events.
Date: December 22, 1998
Creator: Battersby, C.; Dickson, R.; Jennings, R.; Kimmons, J.; Kozlowski, M. R.; Maricle, S. et al.
Object Type: Article
System: The UNT Digital Library
Single-beam photothermal microscopy - a new diagnostic tool for optical materials (open access)

Single-beam photothermal microscopy - a new diagnostic tool for optical materials

A novel photothermal microscopy (PTM) is developed which uses only one laser beam, working as both the pump and the probe. The principle of this single-beam PTM is based on the detection of the second harmonic component of the laser modulated scattering (LMS) signal. This component has a linear dependence on the optical absorptance of the tested area and a quadratic dependence on the pump laser power. Using a pump laser at the wavelengths of 514.5- and 532-nm high-resolution photothermal scans are performed for polished fused silica surfaces and a HfO{sub 2}/SiO{sub 2} multilayer coatings. The results are compared with those from the traditional two-beam PTM mapping. It is demonstrated that the single-beam PTM is more user-friendly (i.e. no alignment is needed) than conventional two-beam PTM and, offers a higher spatial resolution for defect detection.
Date: December 22, 1998
Creator: Feit, M. D.; Kozlowski, M.; Natoli, J. Y.; Rubenchik, A. M.; Sheehan, L.; Wu, Z. L. et al.
Object Type: Article
System: The UNT Digital Library
Gaugino mass without singlets (open access)

Gaugino mass without singlets

In models with dynamical supersymmetry breaking in the hidden sector, the gaugino masses in the observable sector have been believed to be extremely suppressed (below 1 keV), unless there is a gauge singlet in the hidden sector with specific couplings to the observable sector gauge multiplets. We point out that there is a pure supergravity contribution to gaugino masses at the quantum level arising from the superconformal anomaly. Our results are valid to all orders in perturbation theory and are related to the ''exact'' beta functions for soft terms. There is also an anomaly contribution to the A terms proportional to the beta function of the corresponding Yukawa coupling. The gaugino masses are proportional to the corresponding gauge beta functions, and so do not satisfy the usual GUT relations.
Date: December 21, 1998
Creator: Giudice, Gian F.; Luty, Markus A.; Murayama, Hitoshi & Rattazzi, Riccardo
Object Type: Article
System: The UNT Digital Library
Vacuum Energy Cancellation in a Non-supersymmetric String (open access)

Vacuum Energy Cancellation in a Non-supersymmetric String

We present a nonsupersymmetric orbifold of type II string theory and show that it has vanishing cosmological constant at the one and two loop level. We argue heuristically that the cancellation may persist at higher loops.
Date: December 21, 1998
Creator: Kachru, Shamit; Kumar, Jason & Silverstein, Eva
Object Type: Article
System: The UNT Digital Library
Effects of Wet Etch Processing on Laser-Induced Damage of Fused Silica Surfaces (open access)

Effects of Wet Etch Processing on Laser-Induced Damage of Fused Silica Surfaces

Laser-induced damage of transparent fused silica optical components by 355 nm illumination occurs primarily at surface defects produced during the grinding and polishing processes. These defects can either be surface defects or sub-surface damage.Wet etch processing in a buffered hydrogen fluoride (HF) solution has been examined as a tool for characterizing such defects. A study was conducted to understand the effects of etch depth on the damage threshold of fused silica substrates. The study used a 355 nm, 7.5 ns, 10 Hz Nd:YAG laser to damage test fused silica optics through various wet etch processing steps. Inspection of the surface quality was performed with Nomarski microscopy and Total Internal Reflection Microscopy. The damage test data and inspection results were correlated with polishing process specifics. The results show that a wet etch exposes subsurface damage while maintaining or improving the laser damage performance. The benefits of a wet etch must be evaluated for each polishing process.
Date: December 22, 1998
Creator: Battersby, C. L.; Kozlowski, M. R. & Sheehan, L. M.
Object Type: Article
System: The UNT Digital Library
Laser-induced damage of absorbing and diffusing glass surfaces under IR and UV irradiation (open access)

Laser-induced damage of absorbing and diffusing glass surfaces under IR and UV irradiation

None
Date: December 22, 1998
Creator: Bletzer, K; Genin, F Y; Hendrix, J L; Hester, M; Whitman, P K & Yoshiyama, J
Object Type: Article
System: The UNT Digital Library
Results of a live trapping survey for the Alameda whipsnake (masticophis lateralis euryxanthus) at the Site 300 facilities of Lawrence Livermore National Laboratory (open access)
A New Measurement of the Strength of the Superallowed Fermi Branch in the Beta Decay of {sup 10}C with GAMMASPHERE (open access)

A New Measurement of the Strength of the Superallowed Fermi Branch in the Beta Decay of {sup 10}C with GAMMASPHERE

None
Date: December 17, 1998
Creator: Fujikawa, B. K.; Asztalos, S. J.; Clark, R. M.; Deleplanque-Stephens, M.-A.; Fallon, P.; Freedman, S. J. et al.
Object Type: Article
System: The UNT Digital Library
U.S. national nuclear material control and accounting system (open access)

U.S. national nuclear material control and accounting system

Issues related to nuclear material control and accounting and illegal dealing in these materials were discussed at the April 19--20, 1996 Moscow summit meeting (G7 + Russia). The declaration from this meeting reaffirmed that governments are responsible for the safety of all nuclear materials in their possession and for the effectiveness of the national control and accounting system for these materials. The Russian delegation at this meeting stated that ''the creation of a nuclear materials accounting, control, and physical protection system has become a government priority''. Therefore, in order to create a government nuclear material control and accounting system for the Russian Federation, it is critical to study the structure, operating principles, and regulations supporting the control and accounting of nuclear materials in the national systems of nuclear powers. In particular, Russian specialists have a definite interest in learning about the National Nuclear Material Control and Accounting System of the US, which has been operating successfully as an automated system since 1968.
Date: December 1, 1998
Creator: Taylor, S. & Terentiev, V. G.
Object Type: Report
System: The UNT Digital Library
Argonne National Laboratory Institutional Plan FY 1999 - FY 2004. (open access)

Argonne National Laboratory Institutional Plan FY 1999 - FY 2004.

The ''Institutional Plan'' is the culmination of Argonne's annual planning cycle. This document outlines the Laboratory's plans for the optimal development of its research programs and support operations, in the context of national research and development needs, the missions of the Department of Energy and Argonne National Laboratory, and expected resource constraints. The ''Institutional Plan'' is the product of internal planning and extensive discussions with DOE managers.
Date: December 9, 1998
Creator: Beggs, S. D.
Object Type: Report
System: The UNT Digital Library
Introduction to the measurement of noise with application to particle accelerator beam stabilization. (open access)

Introduction to the measurement of noise with application to particle accelerator beam stabilization.

One of the most important figures of merit for a synchrotron radiation source, once specified beam intensity and energy have been achieved, is charged particle beam stability. While a significant effort has been expended at the Advanced Photon Source (APS) to reduce or eliminate undesirable sources of beam motion, it will be necessary to employ active feedback to stabilize the user photon beams to the very stringent levels required. This becomes especially important when one considers that transverse beam stability is generally quoted as a fraction of beam dimensions. Since source brightness tends to be inversely proportional to these transverse dimensions, it should be evident that x-ray beamline users in general will support any and all efforts to reduce the transverse charged particle beam dimensions. The obvious corollary to this is that coincident with emittance reduction efforts must come improvements in our ability to both measure and correct the particle beam trajectory. Presently, there are at least two active proposals at the APS for reducing both horizontal and vertical emittance. A simple change in lattice functions gives a factor of two reduction in horizontal and vertical beam emittance, while a machine studies program focusing on the correction of horizontal-vertical coupling …
Date: December 21, 1998
Creator: Decker, G.
Object Type: Report
System: The UNT Digital Library
Bioavailability: implications for science/cleanup policy (open access)

Bioavailability: implications for science/cleanup policy

This paper examines the role of bioavailability in risk assessment and cleanup decisions. Bioavailability refers to how chemicals ''behave'' and their ''availability'' to interact with living organisms. Bioavailability has significant implications for exposure risks, cleanup goals, and site costs. Risk to human health and the environment is directly tied to the bioavailability of the chemicals of concern.
Date: December 1, 1998
Creator: Denit, Jeffery & Planicka, J. Gregory
Object Type: Report
System: The UNT Digital Library
In situ destruction of contaminants via hydrous pyrolysis/ oxidation:Visalia Field Test (open access)

In situ destruction of contaminants via hydrous pyrolysis/ oxidation:Visalia Field Test

A field test of hydrous pyrolysis/oxidation (HPO) was conducted during the summer of 1997, during a commercial application of thermal remediation (Dynamic Underground Stripping (DUS)) at the Visalia Pole Yard (a super-fund site) in southern California. At Visalia, Southern California Edison Co. is applying the DUS thermal remediation method to clean up a large (4.3 acre) site contaminated with pole-treating compounds. This is a full-scale cleanup, during which initial extraction of contaminants is augmented by combined steam/air injection in order to enhance the destruction of residual contaminants by HPO. Laboratory results indicate that the contaminants at Visaha react at similar rates to TCE, which has been the focus of extensive laboratory work (Knauss et al., 1998a-c). Field experimental results from this application yield valuable information (1) confirming the destruction of contaminants in soil and groundwater by HPO, (2) validating the predictive models used to design HP0 steam injection systems, (3) demonstrating that accurate field measurements of the critical fluid parameters can be obtained using existing monitoring wells and (4) obtaining a reasonable prediction of the cost and effectiveness of HPO, working at a commercial scale and with commercial partners. The goal of our additional study and demonstration in conjunction with …
Date: December 1, 1998
Creator: Aines, R. D.; Carrigan, C.; Chiarappa, M.; Eaker, C.; Hudson, B.; Knauss, K. et al.
Object Type: Report
System: The UNT Digital Library
Berkeley Lab to Help Build Straw Bale Building (open access)

Berkeley Lab to Help Build Straw Bale Building

The Shorebird Environmental Learning Center (SELC) is a new straw bale building that will showcase current and future technologies and techniques that will reduce the environmental impacts of building construction and operations. The building will also serve as a living laboratory to test systems and monitor their performance. The project will be the model for a building process that stops using our precious resources and reduces waste pollution. The rice straw that will be used for the bale construction is generally waste material that is typically burned--millions of tons of it a year--especially in California's San Joaquin Valley. Buildings have significant impacts on the overall environment. Building operations, including lighting, heating, and cooling, consume about 30% of the energy used in the United States. Building construction and the processes into making building materials consume an additional 8% of total energy. Construction also accounts for 39% of wood consumed in the U S, while 25% of solid waste volume is construction and demolition (C &D) debris. The SELC will incorporate a variety of materials and techniques that will address these and other issues, while providing a model of environmentally considered design for Bay Area residents and builders. Environmental considerations include energy …
Date: December 1998
Creator: Worsham, S. A. & Van Mechelen, G.
Object Type: Article
System: The UNT Digital Library
Site S-7 Representative Model and Application for the Vadose Zone Monitoring System (VZMS) McClellan AFB - 1998 Semi-Annual Report (open access)

Site S-7 Representative Model and Application for the Vadose Zone Monitoring System (VZMS) McClellan AFB - 1998 Semi-Annual Report

Vadose zone data collection and enhanced data analysis are continuing for the Vadose Zone Monitoring System (VZMS) installed at site S-7 in IC 34 at McClellan MB. Data from core samples from boreholes drilled in 1998 and from VZMS continuous monitoring are evaluated and compared to previously collected data and analyses. The suite of data collected to date is used to develop and constrain a spatially averaged, one-dimensional site S-7 representative model that is implemented into T2VOC. Testing of the conceptual model under conditions of recharge of 100 mm/yr produces plausible moisture contents relative to data from several sources. Further scoping calculations involving gas-phase TCE transport in the representative model were undertaken. We investigate the role of recharge on TCE transport as well as the role of ion- and gas-phase flow driven by density and barometric pumping effects. This report provides the first example of the application of the site S-7 representative model in th e investigation of subsurface VOC movement.
Date: December 1, 1998
Creator: James, A. L. & Oldenburg, C. M.
Object Type: Report
System: The UNT Digital Library
NITROGEN INTERACTIONS AND PHOTOSYNTHETIC RESPONSES TO CO2: WORK PLAN FOR BIOCON EXPERIMENT/PHYSIOLOGICAL MEASUREMENTS AT CEDAR CREEK. (open access)

NITROGEN INTERACTIONS AND PHOTOSYNTHETIC RESPONSES TO CO2: WORK PLAN FOR BIOCON EXPERIMENT/PHYSIOLOGICAL MEASUREMENTS AT CEDAR CREEK.

The objective of this report is to determine Nitrogen and Biodiversity (N-fixer) effects on photosynthetic responses in interaction with elevated CO{sub 2} in the BioCON FACE experiment.
Date: December 31, 1998
Creator: ELLSWORTH,D.
Object Type: Report
System: The UNT Digital Library
Radiographic simulations and analysis for ASCI (open access)

Radiographic simulations and analysis for ASCI

In this paper, the authors describe their work on developing quantitatively accurate radiographic simulation and analysis tools for ASCI hydro codes. they have extended the ability of HADES, the code which simulates radiography through a mesh, to treat the complex meshes used in ASCI calculations. The ultimate goal is to allow direct comparison between experimental radiographs and full physics simulated radiographs of ASCI calculations. They describe the ray-tracing algorithm they have developed for fast, accurate simulation of dynamic radiographs with the meshes used in ALE3D, an LLNL ASCI code. Spectral effects and material compositions are included. In addition to the newness of the mesh types, the distributed nature of domain decomposed problems requires special treatment by the radiographic code. Because of the size of such problems, they have parallelized the radiographic simulation, in order to have quick turnaround time. presently, this is done using the domain decomposition from the hydro code. They demonstrate good parallel scaling as the size of the problem is increased. They show a comparison between an experimental radiograph of a high explosive detonation and a simulated radiograph of an ALE3D calculation. They conclude with a discussion of future work.
Date: December 18, 1998
Creator: Aufderheide, M.; Stone, D. & VonWittenau, A.
Object Type: Article
System: The UNT Digital Library
Graphical interface for the physics-based generation of inputs to 3D MEEC SGEMP and SREMP simulations (open access)

Graphical interface for the physics-based generation of inputs to 3D MEEC SGEMP and SREMP simulations

A graphical user interface (GUI) is under development for the MEEC family of SGEMP and SREMP simulation codes. These codes are workhorse legacy codes that have been in use for nearly two decades, with modifications and enhanced physics models added throughout the years. The MEEC codes are currently being evaluated for use by the DOE in the Dual Revalidation program and experiments at NIF. The new GUI makes the codes more accessible and less prone to input errors by automatically generating the parameters and grids that previously had to be designed by hand. physics-based algorithms define the simulation volume with expanding meshes. Users are able to specify objects, materials, and emission surfaces through dialogs and input boxes. 3D and orthographic views are available to view objects in the volume. Zone slice views are available for stepping through the overlay of objects on the mesh in planes aligned with the primary axes.
Date: December 1, 1998
Creator: Bland, M; Wondra, J; Nunan, S & Walters, D
Object Type: Article
System: The UNT Digital Library
ADVANCED SULFUR CONTROL CONCEPTS FOR HOT GAS DESULFURIZATION TECHNOLOGY (open access)

ADVANCED SULFUR CONTROL CONCEPTS FOR HOT GAS DESULFURIZATION TECHNOLOGY

The objective of this project is to develop a hot-gas desulfurization process scheme for control of H{sub 2}S in HTHP coal gas that can be more simply and economically integrated with known regenerable sorbents in DOE/METC-sponsored work than current leading hot-gas desulfurization technologies. In addition to being more economical, the process scheme to be developed must yield an elemental sulfur byproduct.
Date: December 31, 1998
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Biochemical Contributions to Corrosion of Carbon Steel and Alloy 22 in a Continual Flow System (open access)

Biochemical Contributions to Corrosion of Carbon Steel and Alloy 22 in a Continual Flow System

Microbiologically influenced corrosion (MIC) may decrease the functional lifetime of nuclear waste packaging materials in the potential geologic repository at Yucca Mountain (YM), Nevada. Biochemical contributions to corrosion of package materials are being determined in reactors containing crushed repository-site rock with the endogenous microbial community, and candidate waste package materials. These systems are being continually supplied with simulated ground water. Periodically, bulk chemistries are analyzed on the system outflow, and surfacial chemistries are assessed on withdrawn material coupons. Both Fe and Mn dissolved from C1020 coupons under conditions that included the presence of YM microorganisms. Insoluble corrosion products remained in a reduced state at the coupon surface, indicating at least a localized anoxic condition; soluble reduced Mn and Fe were also detected in solution, while precipitated and spalled products were oxidized. Alloy 22 surfaces showed a layer of chrome oxide, almost certainly in the Cr(III) oxidation state, on microcosm-exposed coupons, while no soluble chrome was detected in solution. The results of these studies will be compared to identical testing on systems containing sterilized rock to generate, and ultimately predict, microbial contributions to waste package corrosion chemistries.
Date: December 3, 1998
Creator: Horn, J.; Martin, S.; Masterson, B. & Lian, T.
Object Type: Article
System: The UNT Digital Library
The effect of low dose-rate irradiation on the microstructure of 304 stainless steel. (open access)

The effect of low dose-rate irradiation on the microstructure of 304 stainless steel.

Changes in mechanical and corrosion properties caused by the development of radiation-induced microstructure have relevance to the aging and lifetime extension of light water reactors (LWR's). However, much of the current data related to microstructural development in irradiated metals are generated from studies carried out at much higher dose-rates than encountered in LWR's. An opportunity exists to study the influence of low dose-rate irradiation on microstructural development for a variety of structural and surveillance materials extracted from the experimental breeder reactor EBR-II. In this study, irradiated 304 stainless steel hexagonal ''hex'' duct material is examined in order to compare microstructure in the dose-rate range of 10{sup {minus}7}-10{sup {minus}9} dpakec. The samples, taken from the reflector locations in EBR-II, experienced a total dose between 10 and 12 dpa at a temperature of {approximately}375 C. Transmission electron microscopy (TEM) results reveal that there is a moderate dose-rate effect on microstructural development for samples irradiated in the range of 2 x 10{sup {minus}8} to 4 x 10{sup {minus}8} dpa/sec, however a substantial dose rate-effect exists between dose-rates of 2 x 10{sup {minus}8} and 1 x 10{sup {minus}9} dpa/sec Transmission electron microscopy (TEM) results will detail the development of the microstructure in terms of …
Date: December 2, 1998
Creator: Cole, J. I.
Object Type: Article
System: The UNT Digital Library
Superdeformation in the A=150 and A=190 regions. (open access)

Superdeformation in the A=150 and A=190 regions.

Superdeformation has been established for over a decade in the mass 150 region and nearly as long in the A=190 region. The first measurements directed at nuclei in these regions concentrated on mapping out the superdeformed (SD) islands by identifying SD rotational bands in {gamma}-ray coincidence data. These early studies provided new insights into the physics of superdeformation, but also raised unexpected issues. The new gamma-ray arrays (Gammasphere, Eurogam/Euroball and Gasp) have provided a wealth of new data on properties of SD states in these two mass regions. This paper highlights some of the more recent results from the large arrays which have addressed the outstanding issues in the field, namely, {Delta}I = 4 staggering, identical bands, SD vibrational bands, and questions about the feeding into and the decay out of the SD well.
Date: December 1, 1998
Creator: Carpenter, M. P.
Object Type: Article
System: The UNT Digital Library
Gas Bubble Trauma Monitoring in the Clearwater River Drainage, Idaho 1998. (open access)

Gas Bubble Trauma Monitoring in the Clearwater River Drainage, Idaho 1998.

Select portions of the Clearwater and North Fork of the Clearwater rivers were electroshocked to estimate the incidence of gas bubble trauma (GBT) occurring in resident fish populations for the spring and summer months of 1998. The study area was divided into four sections and sampled weekly during periods of spill and non-spill from Dworshak Dam. Five thousand five hundred and forty one fish, representing 22 different species, were captured and examined for GBT. Two fish were detected with signs of GBT; exhibiting the lowest incidence of GBT in the last four years (0.04%). Reduced discharge and lower levels of total dissolved gases may have resulted in lower incidence of GBT in the 1998 monitoring period.
Date: December 1, 1998
Creator: Cochnauer, Tim
Object Type: Report
System: The UNT Digital Library
Structural analysis of a completely amorphous {sup 238}Pu-doped zircon by neutron diffraction. (open access)

Structural analysis of a completely amorphous {sup 238}Pu-doped zircon by neutron diffraction.

The structure of a completely amorphous zircon was determined by time-of-flight neutron diffraction at Argonne's Intense Pulsed Neutron Source (IPNS). The sample of metamict zircon (ZrSiO{sub 4}),initially doped to 8.85 weight percent {sup 238}Pi, had been completely amorphized by alpha-recoil damage since its synthesis in 1981 at the Pacific Northwest National Laboratory (PNNL). The measured diffraction structure factor, S(Q), indicated a completely amorphous sample, with no signs of residual zircon microcrystallinity. The pair distribution function obtained indicated that the structure was that of an oxide glass, retaining the Si-0, Zr-0, and O-O bond lengths of crystalline zircon.
Date: December 16, 1998
Creator: Fortner, J. A.
Object Type: Article
System: The UNT Digital Library