Design and reality for NIF ignition targets (open access)

Design and reality for NIF ignition targets

Advances in ICF experiments and modeling have led to improved understanding of the growth of instabilities during capsule implosion and the effects on capsule performance. This has led to more refined specifications on the characteristics of igniting capsules, all of which have solid D-T fuel layers. These specifications involve a trade-off between the interior ice surface structure, outer capsule surface structure, and time-dependent drive asymmetry.
Date: May 31, 1996
Creator: Bernat, T.P.
System: The UNT Digital Library
Developing shape analysis tools to assist complex spatial decision making (open access)

Developing shape analysis tools to assist complex spatial decision making

The objective of this research was to develop and implement a shape identification measure within a geographic information system, specifically one that incorporates analytical modeling for site location planning. The application that was developed incorporated a location model within a raster-based GIS, which helped address critical performance issues for the decision support system. Binary matrices, which approximate the object`s geometrical form, are passed over the grided data structure and allow identification of irregular and regularly shaped objects. Lastly, the issue of shape rotation is addressed and is resolved by constructing unique matrices corresponding to the object`s orientation
Date: May 31, 1996
Creator: Mackey, H. E.; Ehler, G. B. & Cowen, D.
System: The UNT Digital Library
Forming and smoothing D{sub 2} and HD layers for ICF by infra-red heating (open access)

Forming and smoothing D{sub 2} and HD layers for ICF by infra-red heating

We describe a technique to form and smooth uniform solid D{sub 2}, HD or DT layers for inertial confinement fusion targets. Pumping the infrared (IR) collision induced vibration-rotation band generates a bulk heating of the solid. Shadowgraphs reveal that this bulk heat quickly redistributes the solid into a relatively uniform layer depending on the IR intensity profile. Measured redistribution time constants are used to determine the conversion efficiency of IR light into bulk heat. Phase shifting interferometry reveals that the surface roughness decreases with increasing IR heating.
Date: May 31, 1996
Creator: Collins, G.W.; Tiszauer, D.; Feit, M.; Mapoles, E.R.; Bernat, T.P.; Bittner, D.N. et al.
System: The UNT Digital Library
Development of hydrogen-fueled fuel cell-powered light-duty transportation engine (open access)

Development of hydrogen-fueled fuel cell-powered light-duty transportation engine

To avoid the dire consequences, and yet ensure continued economic development, from the expected large increase in the global automobile population in the Third World, the transportation sector needs to move away from the internal combustion engine to fuel cell powered vehicles that operate on hydrogen. A research, development, and demonstration (RD&D) program is proposed to establish the superiority of the hydrogen-fueled, PEM (proton exchange membrane) fuel cell-powered engine compared to the present internal combustion engine powertrain. This new drivetrain will lead to a major decrease in environmental pollution. ORNL is seeking funding to undertake this RD&D program.
Date: May 30, 1996
Creator: Singh, S. P. N.; Adams, D. J. & Keever, J. W.
System: The UNT Digital Library
Fire hazard analyses and safety analysis reports relationship (open access)

Fire hazard analyses and safety analysis reports relationship

DOE Order 5480.7A requires that Fire Hazard Analyses (FHA) be performed for new facilities, for facilities requiring a DOE 5480.23 Safety Analysis, or as directed by the DOE Program Secretarial Officer. DOE Order 5480.23 requires that a Safety Analysis Report (SAR) be prepared for DOE nuclear facilities. Both the FHA and SAR `documents provide important information and direction for facility design and operation. Each of the two documents address the effects of postulated fire scenarios, and both have common or at least consistent bases, and have overlapping elements. However, some of the objectives of the required analyses are distinctly different. These differences have historically resulted in variations in the interpretation and Understanding of the DOE Orders and associated guidance by organizations and individuals within the Westinghouse Hanford Company.
Date: May 30, 1996
Creator: Olson, W. W.
System: The UNT Digital Library
Matrix market: a web resource for test matrix collection (open access)

Matrix market: a web resource for test matrix collection

We describe a repository of data for the testing of numerical algorithms and mathematical software for matrix computations. The repository is designed to accommodate both dense and sparse matrices, as well as software to generate matrices. It has been seeded with the well known Harwell-Boeing sparse matrix collection. The raw data files have been augmented with an integrated World Wide Web interface which describes the matrices in the collection quantitatively and visually, For example, each matrix has a Web page which details its attributes, graphically depicts its sparsity pattern, and provides access to the matrix itself in several formats. In addition, a search mechanism is included which allows retrieval of matrices based on a variety of attributes, such as type and size, as well as through free-text search in abstracts. The URL is http://math.nist.gov/MatrixMarket.
Date: May 30, 1996
Creator: Boisvert, R. F.; Pozo, R.; Remington, K.; Barrett, R. F. & Dongarra, J. J.
System: The UNT Digital Library
Measurement of the in-flight pusher density of an indirect drive capsule implosion core using x-ray backlighting (open access)

Measurement of the in-flight pusher density of an indirect drive capsule implosion core using x-ray backlighting

Both the efficiency of an implosion and the growth rate of hydrodynamic instability increase with the aspect ratio of an implosion. In order to study the physics of implosions with high Rayleigh-Taylor growth factors, we use doped ablators which should minimize x-ray preheat and shell decompression, and hence increase in- flight aspect ratio. We use x-ray backlighting techniques to image the indirectly-driven capsules. We record backlit 4.7 KeV images of the full capsule throughout the implosion phase with 55 ps and 15{mu}m resolution. We use these images to measure the in-flight aspect ratios for doped ablators, and we infer the radial density profile as a function of time by Abel inverting the transmission profiles.
Date: May 30, 1996
Creator: Kalantar, D. H.; Haan, S. W.; Hammel, B. A.; Keane, C. J.; Landen, O. L. & Munro, D. H.
System: The UNT Digital Library
Assessment of first wall damage from target x-ray emission and scattered laser light for the National Ignition Facility (open access)

Assessment of first wall damage from target x-ray emission and scattered laser light for the National Ignition Facility

Predictions for NIF ICF target x-ray emission are presented. Validation experiments confirm the key features of the x-ray emissions and their effects on the NIF chamber B{sub 4}C first wall. Predictions of a possible first wall 0.35-{mu}m laser radiation compared to more experimental results conducted to determine B{sub 4}C response all suggest B{sub 4}C is an acceptable first wall material.
Date: May 29, 1996
Creator: Tobin, M.T.; Anderson, A.; Burnham, A. & Bernat, T.
System: The UNT Digital Library
RFQ-based, transportable, high-resolution, neutron radiography system concept (open access)

RFQ-based, transportable, high-resolution, neutron radiography system concept

A preliminary design for a high-resolution transportable neutron radiography system concept has been developed. The system requirement has been taken to be a thermal neutron flux of 10{sup 6} N/(cm{sup 2}- sec) with an L/D of 100. The approach is to use an accelerator-driven neutron source, with a radiofrequency quadrupole (RFQ) as the primary accelerator component. Initial concepts for all of the major components of the system have been developed, and selected key parts have been examined further. An overview of the system design is presented, together with brief summaries of the concepts for the ion source, LEBT, RFQ, HEBT, target, moderator, collimator, image collection, power, cooling, vacuum, structure, robotics, control system, data analysis, transport vehicle, and site support. More detailed studies completed for the RFQ and moderator designs, and issues identified during the course of the work, are described.
Date: May 29, 1996
Creator: Gillespie, G.H.; McMichael, G.E.; Micklich, B.J. & Imel, G.R.
System: The UNT Digital Library
A general protocol for restoration of entire river catchments (open access)

A general protocol for restoration of entire river catchments

Large catchment basins may be viewed as ecosystems with interactive natural and cultural attributes. Stream regulation severs ecological connectivity between channels and flood plains by reducing the range of natural flow and temperature variation, reduces the capacity of the ecosystem to sustain native biodiversity and bioproduction and promotes proliferation of non-native biota. However, regulated rivers regain normative attributes, which promote recovery of native biota, as distance from the dam increases and in relation to the mode of regulation. Therefore, reregulation of flow and temperature to normative pattern, coupled with elimination of pollutants and constrainment of nonnative biota, can naturally restore damaged habitats from headwaters to mouth. The expectation is rapid recovery of depressed populations of native species. The protocol requires: restoration of seasonal temperature patterns; restoration of peak flows needed to reconnect and periodically reconfigure channel and floodplain habitats; stabilization of base flows to revitalize the shallow water habitats; maximization of dam passage to allow restoration of metapopulation structure; change in the management belief system to rely on natural habitat restoration as opposed to artificial propagation, installation of artificial instream structures (river engineering) and artificial food web control; and, practice of adaptive ecosystem management.
Date: May 28, 1996
Creator: Stanford, Jack A.; Frissell, Christopher A.; Ward, J. V.; Liss, William J.; Coutant, Charles C.; Williams, Richard N. et al.
System: The UNT Digital Library
Thermal management technology for hydrogen storage: Fullerene option (open access)

Thermal management technology for hydrogen storage: Fullerene option

Fullerenes were picked as first option for H storage because of potentially high volumetric and gravimetric densities. Results indicate that about 6 wt% H (corresponding to C{sub 60}H{sub 48}) can be added to and taken out of fullerenes. A model with thermally activated hydrogenation/dehydrogenation was developed. Activation energies were estimated to be 100 and 160 kJ/mole (1.0 and 1.6 eV/H{sub 2}) for hydrogenation and dehydrogenation, respectively; difference is interpreted as heat release during hydrogenation. The activation energies and hydrogenation heat may be modifiable by catalysts. Preliminary H storage simulations for a conceptually simple device were performed (a 1-m long hollow metal cylinder with inner dia 0.02 m filled with fullerene powders). Results indicate that the thermal diffusivity of the fullerenes controls the hydrogenation and dehydrogenation rates. Rates can be significantly modified by changing the thermal diffusivity, eg, by incorporating a metal mesh. The simulation suggest that thermal management is essential for efficient H storage devices using fullerenes. More controlled experiments, model development, and physical property determinations are needed; catalyst use also needs to be pursued. Future ORNL/MER cooperative work is planned.
Date: May 28, 1996
Creator: Wang, J. C.; Chen, F. C. & Murphy, R. W.
System: The UNT Digital Library
Characterization of SAL605 negative resist at {lambda}=13 nm (open access)

Characterization of SAL605 negative resist at {lambda}=13 nm

We have characterized the response of the negative resist SAL605 in the extreme ultraviolet ({lambda}=13 nm). The sensitivity was found to be {approx}1 mJ/cm{sup 3} for all conditions studied. We have identified processing conditions leading to high ({gamma}{gt}4) contrast. The resist response was modeled using Prolith/2 and the development parameters were obtained from the exposure curves.
Date: May 24, 1996
Creator: La Fontaine, B.; Ciarlo, D.; Gaines, D. P. & Kania, D. R.
System: The UNT Digital Library
Measuring the effect of scatter on the performance of a lithography system (open access)

Measuring the effect of scatter on the performance of a lithography system

The distribution of scattered light at the image plane of an extreme ultraviolet lithography (EUVL) system was measured, in situ. These measurements revealed a significant degradation of the modulation transfer function of the imaging optic, relative to its value in the absence of scattering.
Date: May 24, 1996
Creator: La Fontaine, B.; Daly, T. P.; Chapman, H. N.; Gaines, D. P.; Stearns, D. G.; Sweeney, D. W. et al.
System: The UNT Digital Library
Performance of a two-mirror, four-reflection, ring-field optical system at {lambda}=13 nm (open access)

Performance of a two-mirror, four-reflection, ring-field optical system at {lambda}=13 nm

Performance of an Extreme Ultraviolet Lithography (EUVL) imaging optic was characterized by printing resolution test images in resist. While features as small as 0.137 {mu}m were successfully printed, a resolution of 0.175 {mu}m better represents the performance of the system over the full 0.9 mm{sup 2} image field. The contrast of the aerial image was estimated to be about 40% or less for the fine features printed. This low contrast value is attributed to a degradation of the modulation transfer function due to presence of scattered light in the image.
Date: May 24, 1996
Creator: La Fontaine, B.; Gaines, D. P.; Kania, D. R.; Sommargren, G. E.; Baker, S. L. & Ciarlo, D.
System: The UNT Digital Library
Preliminary investigation of an additive approach to the fabrication of precision aspheres (open access)

Preliminary investigation of an additive approach to the fabrication of precision aspheres

We report progress in the aspherization of precision optical substrates via deposition of graded period Mo/Si multilayer coatings using a masking technique. These preliminary results show good agreement between the measured and desired thickness profiles over 85% of the sample, however, thickness deviations of up to 7 % are observed in the central area. The errors are attributed to misalignments of the mask relative to the substrate during deposition.
Date: May 24, 1996
Creator: Weber, F.W.; Montcalm, C.; Vernon, S.P. & Kania, D.R.
System: The UNT Digital Library
Introduction to Python (open access)

Introduction to Python

This report contains viewgraphs on a object-oriented programming language called Python. The basic elements of Python and its new numerical extension are discussed.
Date: May 23, 1996
Creator: Dubois, P.F.
System: The UNT Digital Library
A review of ELMs in divertor tokamaks (open access)

A review of ELMs in divertor tokamaks

This paper reviews what is known about edge localized modes (ELMs), with an emphasis on their effect on the scrape-off layer and divertor plasmas. ELM effects have been measured in the ASDEX-U, C-Mod, COMPASS-D, DIII-D, JET, JFT-2M,JT-60U, and TCV tokamaks and are reported here. At least three types of ELMs have been identified and their salient features determined. Type-1 giant ELMs can cause the sudden loss of up to 10-15% of the plasma stored energy but their amplitude ({Delta}W/W) does not increase with increasing power. Type- 3 ELMs are observed near the H-mode power threshold and produce small energy dumps (1-3% of the stored energy). All ELMs increase the scrape- off layer plasma and produce particle fluxes on the divertor targets which are as much as ten times larger that the quiescent phase between ELMs. The divertor heat pulse is largest on the inner target, unlike that of L-Mode or quiescent H-mode; some tokamaks report radial structure in the heat flux profile which is suggestive of islands or helical structures. The power scaling of Type-1 ELM amplitude and frequency have been measured in several tokamaks and has recently been applied to predictions of the ELM Size in ITER. Concern over …
Date: May 23, 1996
Creator: Hill, D.N.
System: The UNT Digital Library
Safety overview of the National Ignition Facility (open access)

Safety overview of the National Ignition Facility

The National Ignition Facility (NIF) is a proposed US Department of Energy inertial confinement laser fusion facility. The candidate sites for locating the NIF are: Los Alamos National Laboratory, Sandia National Laboratory, the Nevada Test Site, and Lawrence Livermore National Laboratory (LLNL), the preferred site. The NIF will operate by focusing 192 laser beams onto a tiny deuterium- tritium target located at the center of a spherical target chamber. The NIF mission is to achieve inertial confinement fusion (ICF) ignition, access physical conditions in matter of interest to nuclear weapons physics, provide an above ground simulation capability for nuclear weapons effects testing, and contribute to the development of inertial fusion for electrical power production. The NIF has been classified as a radiological, low hazard facility on the basis of a preliminary hazards analysis and according to the DOE methodology for facility classification. This requires that a safety analysis be prepared under DOE Order 5481.1B, Safety Analysis and Review System. A draft Preliminary Safety Analysis Report (PSAR) has been written, and this will be finalized later in 1996. This paper summarizes the safety issues associated with the operation of the NIF. It provides an overview of the hazards, estimates maximum routine …
Date: May 23, 1996
Creator: Brereton, S.J.; McLouth, L.; Odell, B.; Singh, M.; Tobin, M. & Trent, M.
System: The UNT Digital Library
Efficient production of 2--10 keV x-rays by laser heated ``underdense radiators`` (open access)

Efficient production of 2--10 keV x-rays by laser heated ``underdense radiators``

The next generation of high power lasers offers the prospect of creating multi-kilovolt x-rays with {gt}10% efficiency. Such efficiencies are achieved with ``underdense radiators``, a non- traditional source of laser generated x-rays. Applications of these sources with the proposed National Ignition Facility (NIF) include volume preheating of experiments; bright, multi-keV backlighting; pumps for fluorescent imaging of capsule dopants and Doppler velocimetry; uniform irradiation of large test objects. This paper presents two-dimensional numerical simulations for these high power lasers with unprecedented efficiency.
Date: May 22, 1996
Creator: Suter, L. J.; Kauffman, R. L.; Maxon, M. S. & Davis, J. F.
System: The UNT Digital Library
EUVL reticle factory model and reticle cost analysis (open access)

EUVL reticle factory model and reticle cost analysis

The key issues in reticle manufacturing are cost and delivery time, both of which are dependent upon the yield of the process line. To estimate the cost and delivery time for EUVL reticles in commercial manufacturing, we have developed the first model for an EUV reticle factory which includes all the tools required for a presumed EUVL reticle fabrication process. This model includes the building, support tools and sufficient ``in-line`` process tools for the manufacture of (more than) 2500 reticles per year. Industry specifications for the tool performance are used to determine the number of tools required per process step and the average number of reticles fabricated per year. Building and capital equipment depreciation costs, tool installation costs, tool maintenance costs, labor, clean room costs, process times and process yields are estimated and used to calculate the yearly operating cost of the reticle factory and the average reticle fabrication cost. We estimate the sales price of an EUV reticle to be $60K for non-critical levels and $120K for ``leading-edge.`` The average reticle fabrication time is calculated for three different process-line yields.
Date: May 22, 1996
Creator: Hawryluk, A.M.; Shelden, G. & Troccolo, P.
System: The UNT Digital Library
Science of consciousness and the hard problem (open access)

Science of consciousness and the hard problem

Quantum theory is essentially a rationally coherent theory of the interaction of mind and matter, and it allows our conscious thoughts to play a causally efficacious and necessary role in brain dynamics. It therefore provides a natural basis, created by scientists, for the science of consciousness. As an illustration it is explained how the interaction of brain and consciousness can speed up brain processing, and thereby enhance the survival prospects of conscious organisms, as compared to similar organisms that lack consciousness. As a second illustration it is explained how, within the quantum framework, the consciously experienced {open_quotes}I{close_quotes} directs the actions of a human being. It is concluded that contemporary science already has an adequate framework for incorporating causally efficacious experimential events into the physical universe in a manner that: (1) puts the neural correlates of consciousness into the theory in a well defined way, (2) explains in principle how the effects of consciousness, per se, can enhance the survival prospects of organisms that possess it, (3) allows this survival effect to feed into phylogenetic development, and (4) explains how the consciously experienced {open_quotes}I{close_quotes} can direct human behaviour.
Date: May 22, 1996
Creator: Stapp, Henry P.
System: The UNT Digital Library
Vapor sampling of the headspace of radioactive waste storage tanks (open access)

Vapor sampling of the headspace of radioactive waste storage tanks

This paper recants the history of vapor sampling in the headspaces of radioactive waste storage tanks at Hanford. The first two tanks to receive extensive vapor pressure sampling were Tanks 241-SY-101 and 241-C-103. At various times, a gas chromatography, on-line mass spectrometer, solid state hydrogen monitor, FTIR, and radio acoustic ammonia monitor have been installed. The head space gas sampling activities will continue for the next few years. The current goal is to sample the headspace for all the tanks. Some tank headspaces will be sampled several times to see the data vary with time. Other tanks will have continuous monitors installed to provide additional data.
Date: May 22, 1996
Creator: Reynolds, D. A.
System: The UNT Digital Library
Experimental Investigation of the Classical Rayleigh-Taylor Instability (open access)

Experimental Investigation of the Classical Rayleigh-Taylor Instability

The evolution of the Rayleigh-Taylor (RT) instability in a compressible medium has been investigated at an accelerating embedded interface and at the ablation front in a series of experiments on the Nova laser. The x-ray drive generated in a gold hohlraum ablatively accelerated a planar target consisting of a doped plastic pusher backed by a higher density titanium payload with perturbations placed at the plastic-Ti interface. The targets were diagnosed by face-on and side-on radiography. In previous work focusing on single mode perturbations, wavelengths as short as 10 m have been observed to grow strongly at the embedded interface. Here multimode perturbations consisting of either 2, 10 or 20 modes superposed in phase have been investigated.
Date: May 21, 1996
Creator: Budil, K. S.; Remington, B. A.; Peyser, T. A.; Mikaelian, K. O.; Rubenchik, A. M.; Berning, M. et al.
System: The UNT Digital Library
Industrial ecology at Lawrence Livermore National Laboratory summary statement (open access)

Industrial ecology at Lawrence Livermore National Laboratory summary statement

This statement summarizes Lawrence Livermore National Laboratory`s committment to making important scientific, technological, and business contributions to global sustainability. The quest has many aspects, some socio-political or economic and some technological, and some in which the soft and hard sciences become indistinguishable, as in visionary national strategies, like Holland`s, and futuristic regional and city development plans, like those of Kagoshima and Chattanooga.
Date: May 21, 1996
Creator: Gilmartin, T. J.
System: The UNT Digital Library