The Mercury Project: A High Average Power, Gas-Cooled Laser For Inertial Fusion Energy Development (open access)

The Mercury Project: A High Average Power, Gas-Cooled Laser For Inertial Fusion Energy Development

Hundred-joule, kilowatt-class lasers based on diode-pumped solid-state technologies, are being developed worldwide for laser-plasma interactions and as prototypes for fusion energy drivers. The goal of the Mercury Laser Project is to develop key technologies within an architectural framework that demonstrates basic building blocks for scaling to larger multi-kilojoule systems for inertial fusion energy (IFE) applications. Mercury has requirements that include: scalability to IFE beamlines, 10 Hz repetition rate, high efficiency, and 10{sup 9} shot reliability. The Mercury laser has operated continuously for several hours at 55 J and 10 Hz with fourteen 4 x 6 cm{sup 2} ytterbium doped strontium fluoroapatite (Yb:S-FAP) amplifier slabs pumped by eight 100 kW diode arrays. The 1047 nm fundamental wavelength was converted to 523 nm at 160 W average power with 73% conversion efficiency using yttrium calcium oxy-borate (YCOB).
Date: November 3, 2006
Creator: Bayramian, A.; Armstrong, P.; Ault, E.; Beach, R.; Bibeau, C.; Caird, J. et al.
Object Type: Article
System: The UNT Digital Library
Development of a High-Temperature Smart Transducer Interface Node and Telemetry System (HSTINTS) (open access)

Development of a High-Temperature Smart Transducer Interface Node and Telemetry System (HSTINTS)

Halliburton Energy Services and Oak Ridge National Laboratory established a CRADA to conduct applied research to develop a general purpose, High-Temperature, Smart Transducer Interface Node and Telemetry System (HSTINTS) capable of temporally-coherent multiple-channel, high speed, high-resolution data transuction and acquisition while operating in a hostile thermal, chemical, and pressure environment for extended periods of time over a single coaxial cable. This ambitious, high-risk effort required development of custom dielectric isolated integrated circuits, amplified hybrid couplers for telemetry and an audio-frequency based power supply and distribution system using an engineered application of standing waves to compensate voltage drop along a 2 mile long cable. Several goals were achieved but underestimated challenges and a couple of mistakes hampered progress. When it was determined that an additional year of concerted effort would be required to complete the system demonstration, the sponsor withdrew funding and terminated the effort.
Date: November 3, 2006
Creator: Buckner, M. A.
Object Type: Report
System: The UNT Digital Library
SCC Initiation in Alloy 600 Heat Affected Zones Exposed to High Temperature Water (open access)

SCC Initiation in Alloy 600 Heat Affected Zones Exposed to High Temperature Water

Studies have shown that grain boundary chromium carbides improve the stress corrosion cracking (SCC) resistance of nickel based alloys exposed to high temperature, high purity water. However, thermal cycles from welding can significantly alter the microstructure of the base material near the fusion line. In particular, the heat of welding can solutionize grain boundary carbides and produce locally high residual stresses and strains, reducing the SCC resistance of the Alloy 600 type material in the heat affected zone (HAZ). Testing has shown that the SCC growth rate in Alloy 600 heat affected zone samples can be {approx}30x faster than observed in the Alloy 600 base material under identical testing conditions due to fewer intergranular chromium rich carbides and increased plastic strain in the HAZ [1, 2]. Stress corrosion crack initiation tests were conducted on Alloy 600 HAZ samples at 360 C in hydrogenated, deaerated water to determine if these microstructural differences significantly affect the SCC initiation resistance of Alloy 600 heat affected zones compared to the Alloy 600 base material. Alloy 600 to EN82H to Alloy 600 heat-affected-zone (HAZ) specimens where fabricated from an Alloy 600 to Alloy 600 narrow groove weld with EN82H filler metal. The approximate middle third …
Date: November 3, 2006
Creator: Richey, E.; Morton, D. S.; Etien, R. A.; Young, G. A. & Bucinell, R. B.
Object Type: Article
System: The UNT Digital Library
FEASIBILITY OF HYDROGEN PRODUCTION USING LASER INERTIAL FUSION AS THE PRIMARY ENERGY SOURCE (open access)

FEASIBILITY OF HYDROGEN PRODUCTION USING LASER INERTIAL FUSION AS THE PRIMARY ENERGY SOURCE

The High Average Power Laser (HAPL) program is developing technology for Laser IFE with the goal of producing electricity from the heat generated by the implosion of deuterium-tritium (DT) targets. Alternatively, the Laser IFE device could be coupled to a hydrogen generation system where the heat would be used as input to a water-splitting process to produce hydrogen and oxygen. The production of hydrogen in addition to electricity would allow fusion energy plants to address a much wider segment of energy needs, including transportation. Water-splitting processes involving direct and hybrid thermochemical cycles and high temperature electrolysis are currently being developed as means to produce hydrogen from high temperature nuclear fission reactors and solar central receivers. This paper explores the feasibility of this concept for integration with a Laser IFE plant, and it looks at potential modifications to make this approach more attractive. Of particular interest are: (1) the determination of the advantages of Laser IFE hydrogen production compared to other hydrogen production concepts, and (2) whether a facility of the size of FTF would be suitable for hydrogen production.
Date: November 3, 2006
Creator: Gorensek, M
Object Type: Report
System: The UNT Digital Library
Mechanisms for Fatigue of Micron-Scale Silicon StructuralFilms (open access)

Mechanisms for Fatigue of Micron-Scale Silicon StructuralFilms

Although bulk silicon is not susceptible to fatigue,micron-scale silicon is. Several mechanisms have been proposed to explainthis surprising behavior although the issue remains contentious. Here wedescribe published fatigue results for micron-scale thin siliconfilms andfind that in general they display similar trends, in that lower cyclicstresses result in larger number of cycles to failure in stress-lifetimedata. We further show that one of two classes of mechanisms is invariablyproposed to explain the phenomenon. The first class attributes fatigue toa surface effect caused by subcritical (stable) cracking in thesilicon-oxide layer, e.g., reaction-layer fatigue; the second classproposes that subcritical cracking in the silicon itself is the cause offatigue in Si films. It is our contention that results to date fromsingle and poly crystalline silicon fatigue studies provide no convincingexperimentalevidence to support subcritical cracking in the silicon.Conversely, the reaction-layer mechanism is consistent with existingexperimental results, and moreover provides a rational explanation forthe marked difference in fatigue behavior of bulk and micron-scalesilicon.
Date: November 3, 2006
Creator: Alsem, Daan Hein; Pierron, Olivier N.; Stach, Eric A.; Muhlstein,Christopher L. & Ritchie, Robert O.
Object Type: Article
System: The UNT Digital Library
Thermal Stability and Mechanical Behavior of Ultra-Fine Bcc Ta and v Coatings (open access)

Thermal Stability and Mechanical Behavior of Ultra-Fine Bcc Ta and v Coatings

Ultra-refined microstructures of both tantalum (Ta) and vanadium (V) are produced using electron-beam evaporation and magnetron sputtering deposition. The thermal stability of the micron-to-submicron grain size foils is examined to quantify the kinetics and activation energy of diffusion, as well as identify the temperature transition in dominant mechanism from grain boundary to lattice diffusion. The activation energies for boundary diffusion in Ta and V determined from grain growth are 0.3 and 0.2 eV{center_dot}atom{sup -1}, respectively, versus lattice diffusion values of 4.3 and 3.2 eV{center_dot}atom{sup -1}, respectively. The mechanical behavior, as characterized by strength and hardness, is found to inversely scale with square-root grain size according to the Hall-Petch relationship. The strength of Ta and V increases two-fold from 400 MPa, as the grain size decreases from 2 to 0.75 {micro}m.
Date: November 3, 2006
Creator: Jankowski, Alan Frederic; Go, J. & Hayes, J. P.
Object Type: Article
System: The UNT Digital Library
Overview of Tabletop X-ray Laser Development at the Lawrence Livermore National Laboratory (open access)

Overview of Tabletop X-ray Laser Development at the Lawrence Livermore National Laboratory

It is almost a decade since the first tabletop x-ray laser experiments were implemented at the Lawrence Livermore National Laboratory (LLNL). The decision to pursue the picosecond-driven schemes at LLNL was largely based around the early demonstration of the tabletop Ne-like Ti x-ray laser at the Max Born Institute (MBI) as well as the established robustness of collisional excitation schemes. These picosecond x-ray lasers have been a strong growth area for x-ray laser research. Rapid progress in source development and characterization has achieved ultrahigh peak brightness rivaling the previous activities on the larger facilities. Various picosecond soft-x-ray based applications have benefited from the increased repetition rates. We will describe the activities at LLNL in this area.
Date: November 3, 2006
Creator: Dunn, J.; Shlyaptsev, V.; Nilsen, J.; Smith, R.; Keenan, R.; Moon, S. et al.
Object Type: Article
System: The UNT Digital Library
Investigation of the Rayleigh-Taylor and Richtmyer-Meshkov instabilities (open access)

Investigation of the Rayleigh-Taylor and Richtmyer-Meshkov instabilities

The present research program is centered on the experimental and numerical study of two instabilities that develop at the interface between two different fluids when the interface experiences an impulsive or a constant acceleration. The instabilities, called the Richtmyer-Meshkov and Rayleigh-Taylor instability, respectively, adversely affect target implosion in experiments aimed at the achievement of nuclear fusion by inertial confinement by causing the nuclear fuel contained in a target and the shell material to mix, leading to contamination of the fuel, yield reduction or no ignition at all. The laboratory experiments summarized in this report include shock tube experiments to study a shock-accelerated bubble and a shock-accelerated 2-D sinusoidal interface; and experiments based on the use of magnetorheological fluids for the study of the Rayleigh-Taylor instability. Computational experiments based on the shock tube experimental conditions are also reported.
Date: November 3, 2006
Creator: Bonazza, Riccardo; Anderson, Mark & Oakley, Jason
Object Type: Report
System: The UNT Digital Library
The Use of Aryl Hydrazide Linkers for the Solid Phase Synthesis of Chemically Modified Peptides (open access)

The Use of Aryl Hydrazide Linkers for the Solid Phase Synthesis of Chemically Modified Peptides

Since Merrifield introduced the concept of solid phase synthesis in 1963 for the rapid preparation of peptides, a large variety of different supports and resin-linkers have been developed that improve the efficiency of peptide assembly and expand the myriad of synthetically feasible peptides. The aryl hydrazide is one of the most useful resin-linkers for the synthesis of chemically modified peptides. This linker is completely stable during Boc- and Fmoc-based solid phase synthesis and yet it can be cleaved under very mild oxidative conditions. The present article reviews the use of this valuable linker for the rapid and efficient synthesis of C-terminal modified peptides, head-to-tail cyclic peptides and lipidated peptides.
Date: November 3, 2006
Creator: Woo, Y; Mitchell, A R & Camarero, J A
Object Type: Article
System: The UNT Digital Library
Finding the Axion: The Search for the Dark Matter of the Universe (open access)

Finding the Axion: The Search for the Dark Matter of the Universe

The nature of dark matter has been a mystery for over 70 years. One plausible candidate is the axion, an extremely light and weakly interacting particle, which results from the Peccei-Quinn solution to the strong CP problem. In this proceedings I will briefly review the evidence for dark matter as well as the motivation for the existence of the axion as a prime dark matter candidate. I will then discuss the experimental methods to search for axion dark matter focusing on a sensitive cavity experiment (ADMX) being run at Lawrence Livermore National Laboratory.
Date: November 3, 2006
Creator: Carosi, G.
Object Type: Article
System: The UNT Digital Library
On CH and OOC (open access)

On CH and OOC

None
Date: November 3, 2006
Creator: Noyes, H.Pierre
Object Type: Report
System: The UNT Digital Library
Introduction to Vectorization using the IBM-3090 VF and versus Fortran Release 2 (open access)

Introduction to Vectorization using the IBM-3090 VF and versus Fortran Release 2

None
Date: November 3, 2006
Creator: White, Bebo
Object Type: Report
System: The UNT Digital Library
Demonstration of reduced radiation losses in hohlraums made from cocktail mixtures by measuring increased radiation temperatures (open access)

Demonstration of reduced radiation losses in hohlraums made from cocktail mixtures by measuring increased radiation temperatures

We present results from experiments, numerical simulations, and analytic modeling that demonstrate enhanced radiation confinement of hohlraums made from cocktail materials. We summarize the results from several previous planar sample experiments that showed the potential promise of cocktails. We then discuss a series of more recent hohlraum experiments that attempted to demonstrate enhanced radiation confinement. Once we understood the importance of oxygen contamination in increasing the specific heat and wall losses of uranium-based cocktails, we implemented new manufacturing and handling techniques for cocktail hohlraums that led to our demonstration of a significant increase in radiation temperature (up to +7eV at 300 eV) compared to a pure Au hohlraum. This data agrees well with modeling and suggests we can expect an 18% reduction in wall loss (and 10% reduction in laser energy) for the current ignition design by switching to cocktail hohlraums.
Date: November 3, 2006
Creator: Jones, O.; Schein, J.; Rosen, M.; Suter, L.; Wallace, R.; Dewald, E. et al.
Object Type: Article
System: The UNT Digital Library
Magnetotelluric Data, Rainier Mesa/Shoshone Mountain, Nevada Test Site, Nevada. (open access)

Magnetotelluric Data, Rainier Mesa/Shoshone Mountain, Nevada Test Site, Nevada.

The United States Department of Energy (DOE) and the National Nuclear Security Administration (NNSA) at their Nevada Site Office (NSO) are addressing ground-water contamination resulting from historical underground nuclear testing through the Environmental Management (EM) program and, in particular, the Underground Test Area (UGTA) project. From 1951 to 1992, 828 underground nuclear tests were conducted at the Nevada Test Site northwest of Las Vegas. Most of these tests were conducted hundreds of feet above the ground-water table; however, more than 200 of the tests were near or within the water table. This underground testing was limited to specific areas of the Nevada Test Site, including Pahute Mesa, Rainier Mesa/Shoshone Mountain, Frenchman Flat, and Yucca Flat. One issue of concern is the nature of the somewhat poorly constrained pre-Tertiary geology, and its effects on ground-water flow. Ground-water modelers would like to know more about the hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Rainier Mesa/Shoshone Mountain Corrective Action Unit (Bechtel Nevada, 2006). During 2005, the U.S. Geological Survey (USGS), in cooperation with the DOE and NNSA-NSO, collected and processed data from twenty-six magnetotelluric (MT) and audio-magnetotelluric (AMT) sites at the Nevada Test Site. …
Date: November 3, 2006
Creator: Williams, Jackie M.; Sampson, Jay A.; Rodriguez, Brian D. & Asch., and Theodore H.
Object Type: Report
System: The UNT Digital Library
21st Century Locomotive Technology: Quarterly Technical Status Report 15 DOE/AL68284-TSR15 (open access)

21st Century Locomotive Technology: Quarterly Technical Status Report 15 DOE/AL68284-TSR15

High pressure common rail (HPCR) fuel injection performance testing developed a notch-by-notch performance comparison between HPCR and the production fuel system. A multiple injection screening study at notch 8 was completed with the baseline HPCR fuel injector nozzle tip design. Began a study on performance effects of different nozzle tip geometries. The hybrid locomotive battery vendor performed component fabrication tests and began manufacture of a mockup battery to validate the vibration design performance.
Date: November 3, 2006
Creator: Salasoo, Lembit & Topinka, Jennifer
Object Type: Report
System: The UNT Digital Library