Final Technical Report for USDOE Grant No. DE-FG02-96ER14675 Supermolecular Photosynthetic Arrays: Construction, Characterization, Exploration and Utilization (open access)

Final Technical Report for USDOE Grant No. DE-FG02-96ER14675 Supermolecular Photosynthetic Arrays: Construction, Characterization, Exploration and Utilization

Biological processes provide paradigms for the development of solar energy devices of practical utility. In nature, the light harvesting -complexes (LHCs) are not chemically active. However, with unnatural chemical oxidation by potassium ferricyanide, cation free radicals of bacteriochlorophyll (BChl) can be formed in the light harvesting complex 1 (LH1) of Rhodobacter sphaeroides. Based on EPR studies, the site of the BChl{sup +} cations move rather freely about the LH1 complex as in a molecular wire. These molecular wires function in the frozen, solid state. This work seeks to understand better how nature controls electron transfer in some of its molecular wires. To investigate the nature of electron-hole transfer we have e.onducted both electron paramagnetic resonance (EPR) and electron nuclear double resonance (ENDOR) experiments on oxidized LH1 complexes. Progress has been achieved in two main areas: EPR studies of the role of ferricyanide in the molecular wire nature of oxidized LH1; and ENDOR studies of oxidized LH1 at 80K.
Date: December 13, 2009
Creator: Norris, James
Object Type: Report
System: The UNT Digital Library
The Full Function Test Explosive Generator (open access)

The Full Function Test Explosive Generator

We have conducted three tests of a new pulsed power device called the Full Function Test (FFT). These tests represented the culmination of an effort to establish a high energy pulsed power capability based on high explosive pulsed power (HEPP) technology. This involved an extensive computational modeling, engineering, fabrication, and fielding effort. The experiments were highly successful and a new US record for magnetic energy was obtained.
Date: December 13, 2009
Creator: Reisman, D. B.; Javedani, J. B.; Griffith, L. V.; Ellsworth, G. F.; Kuklo, R. M.; Goerz, D. A. et al.
Object Type: Article
System: The UNT Digital Library
CH Packaging Program Guidance (open access)

CH Packaging Program Guidance

The purpose of this document is to provide the technical requirements for preparation for use, operation, inspection, and maintenance of a Transuranic Package Transporter Model II (TRUPACT-II), a HalfPACT shipping package, and directly related components. This document complies with the minimum requirements as specified in the TRUPACT-II Safety Analysis Report for Packaging (SARP), HalfPACT SARP, and U.S. Nuclear Regulatory Commission (NRC) Certificates of Compliance (C of C) 9218 and 9279, respectively. In the event of a conflict between this document and the SARP or C of C, the C of C shall govern. The C of Cs state: "each package must be prepared for shipment and operated in accordance with the procedures described in Chapter 7.0, Operating Procedures, of the application." They further state: "each package must be tested and maintained in accordance with the procedures described in Chapter 8.0, Acceptance Tests and Maintenance Program of the Application." Chapter 9.0 of the SARP charges the U.S. Department of Energy (DOE) or the Waste Isolation Pilot Plant (WIPP) management and operating (M&O) contractor with assuring packaging is used in accordance with the requirements of the C of C. Because the packaging is NRC-approved, users need to be familiar with Title 10 …
Date: December 13, 2007
Creator: None, None
Object Type: Report
System: The UNT Digital Library
Event-by-Event Simulation of Induced Fission (open access)

Event-by-Event Simulation of Induced Fission

We are developing a novel code that treats induced fission by statistical (or Monte-Carlo) simulation of individual decay chains. After its initial excitation, the fissionable compound nucleus may either deexcite by evaporation or undergo binary fission into a large number of fission channels each with different energetics involving both energy dissipation and deformed scission prefragments. After separation and Coulomb acceleration, each fission fragment undergoes a succession of individual (neutron) evaporations, leading to two bound but still excited fission products (that may further decay electromagnetically and, ultimately, weakly), as well as typically several neutrons. (The inclusion of other possible ejectiles is planned.) This kind of approach makes it possible to study more detailed observables than could be addressed with previous treatments which have tended to focus on average quantities. In particular, any type of correlation observable can readily be extracted from a generated set of events. With a view towards making the code practically useful in a variety of applications, emphasis is being put on making it numerically efficient so that large event samples can be generated quickly. In its present form, the code can generate one million full events in about 12 seconds on a MacBook laptop computer. The development …
Date: December 13, 2007
Creator: Vogt, R. & Randrup, J.
Object Type: Article
System: The UNT Digital Library
Exp6-polar thermodynamics of dense supercritical water (open access)

Exp6-polar thermodynamics of dense supercritical water

We introduce a simple polar fluid model for the thermodynamics of dense supercritical water based on a Buckingham (exp-6) core and point dipole representation of the water molecule. The proposed exp6-polar thermodynamics, based on ideas originally applied to dipolar hard spheres, performs very well when tested against molecular dynamics simulations. Comparisons of the model predictions with experimental data available for supercritical water yield excellent agreement for the shock Hugoniot, isotherms and sound speeds, and are also quite good for the self-diffusion constant and relative dielectric constant. We expect the present approach to be also useful for other small polar molecules and their mixtures.
Date: December 13, 2007
Creator: Bastea, S & Fried, L E
Object Type: Article
System: The UNT Digital Library
Experimental Design for the INL Sample Collection Operational Test (open access)

Experimental Design for the INL Sample Collection Operational Test

This document describes the test events and numbers of samples comprising the experimental design that was developed for the contamination, decontamination, and sampling of a building at the Idaho National Laboratory (INL). This study is referred to as the INL Sample Collection Operational Test. Specific objectives were developed to guide the construction of the experimental design. The main objective is to assess the relative abilities of judgmental and probabilistic sampling strategies to detect contamination in individual rooms or on a whole floor of the INL building. A second objective is to assess the use of probabilistic and Bayesian (judgmental + probabilistic) sampling strategies to make clearance statements of the form “X% confidence that at least Y% of a room (or floor of the building) is not contaminated. The experimental design described in this report includes five test events. The test events (i) vary the floor of the building on which the contaminant will be released, (ii) provide for varying or adjusting the concentration of contaminant released to obtain the ideal concentration gradient across a floor of the building, and (iii) investigate overt as well as covert release of contaminants. The ideal contaminant gradient would have high concentrations of contaminant in …
Date: December 13, 2007
Creator: Amidan, Brett G.; Piepel, Gregory F.; Matzke, Brett D.; Filliben, James J. & Jones, Barbara
Object Type: Report
System: The UNT Digital Library
Flavorful supersymmetry (open access)

Flavorful supersymmetry

Weak scale supersymmetry provides elegant solutions to many of the problems of the standard model, but it also generically gives rise to excessive flavor and CP violation. We show that, if the mechanism that suppresses the Yukawa couplings also suppresses flavor changing interactions in the supersymmetry breaking parameters, essentially all the low energy flavor and CP constraints can be satisfied. The standard assumption of flavor universality in the supersymmetry breaking sector is not necessary. We study signatures of this framework at the LHC. The mass splitting among different generations of squarks and sleptons can be much larger than in conventional scenarios, and even the mass ordering can be changed. We find that there is a plausible scenario in which the next-to-lightest superparticle is a long-lived right-handed selectron or smuon which decays into the lightest superparticle, a gravitino. This leads to the spectacularsignature of monochromatic electrons or muons in a stopper detector, providing strong evidence for the framework.
Date: December 13, 2007
Creator: Nomura, Yasunori; Nomura, Yasunori; Papucci, Michele & Stolarski, Daniel
Object Type: Article
System: The UNT Digital Library
Global Monte Carlo Simulation with High Order Polynomial Expansions (open access)

Global Monte Carlo Simulation with High Order Polynomial Expansions

The functional expansion technique (FET) was recently developed for Monte Carlo simulation. The basic idea of the FET is to expand a Monte Carlo tally in terms of a high order expansion, the coefficients of which can be estimated via the usual random walk process in a conventional Monte Carlo code. If the expansion basis is chosen carefully, the lowest order coefficient is simply the conventional histogram tally, corresponding to a flat mode. This research project studied the applicability of using the FET to estimate the fission source, from which fission sites can be sampled for the next generation. The idea is that individual fission sites contribute to expansion modes that may span the geometry being considered, possibly increasing the communication across a loosely coupled system and thereby improving convergence over the conventional fission bank approach used in most production Monte Carlo codes. The project examined a number of basis functions, including global Legendre polynomials as well as “local” piecewise polynomials such as finite element hat functions and higher order versions. The global FET showed an improvement in convergence over the conventional fission bank approach. The local FET methods showed some advantages versus global polynomials in handling geometries with discontinuous …
Date: December 13, 2007
Creator: Martin, William R.; Holloway, James Paul; Banerjee, Kaushik; Cheatham, Jesse & Conlin, Jeremy
Object Type: Report
System: The UNT Digital Library
MHD Induced Neutral Beam Ion Loss from NSTX Plasmas (open access)

MHD Induced Neutral Beam Ion Loss from NSTX Plasmas

Bursts of ~60 kHz activity on Mirnov coils occur frequently in NSTX plasmas and these are accompanied by bursts of neutral beam ion loss over a range in pitch angles. These losses have been measured with a scintillator type loss probe imaged with a high speed (>10,000 frames/s) video camera, giving the evolution of the energy and pitch angle distributions of the lost neutral beam ions over the course of the events. The instability occurs below the TAE frequency in NSTX (~100 kHz) in high beta plasmas and may be a beta driven Alfvén acoustic (BAAE) mode.
Date: December 13, 2007
Creator: D.S. Darrow, E.D. Fredrickson, N.N. Gorelenkov, A.L. Roquemore, and K. Shinohara
Object Type: Article
System: The UNT Digital Library
Microstructural Characterization of Dislocation Networks During Harper-Dorn Creep of fcc, bcc, and hcp Metals and Alloys (open access)

Microstructural Characterization of Dislocation Networks During Harper-Dorn Creep of fcc, bcc, and hcp Metals and Alloys

Harper-Dorn (H-D) creep is observed in metals and geological materials exposed to very low stresses at temperatures close to the melting point. It is one of several types of creep processes wherein the steady-state strain rate is proportional to the applied stress, Nabarro-Herring creep and Coble creep being two other important processes. H-D creep can be somewhat insidious because the creep rates are much larger than those expected for Nabarro-Herring or Coble creep. Since the working conditions of structural components of power plants and propulsion systems, as well as the motion of the earth’s mantle all involve very low stresses, an understanding of the factors controlling H-D creep is critical in preventing failures associated with those higher-than-expected creep rates. The purpose of this investigation was to obtain missing microstructural information on the evolution of the dislocation structures during static annealing of materials with fcc, bcc and hcp structure and use obtained results to test predictive capabilities of the dislocation network theory of H-D creep. In our view the evolutionary processes during static annealing and during Harper-Dorn creep are intimately related. The materials used in this study were fcc aluminum, hcp zinc and bcc tin. All characterizations of dislocation structures, densities …
Date: December 13, 2007
Creator: Przystupa, Marek A.
Object Type: Report
System: The UNT Digital Library
Soil Sampling Plan in Support of the Human Health and Ecological Risk Assessment for the Operation of the Explosives Waste Treatment Facilitiy at Site 300 of the Lawrence Livermore National Laboratory (open access)

Soil Sampling Plan in Support of the Human Health and Ecological Risk Assessment for the Operation of the Explosives Waste Treatment Facilitiy at Site 300 of the Lawrence Livermore National Laboratory

LLNL proposes to obtain soil samples from the following areas: (1) Four areas downwind of the Explosives Waste Treatment Facility (EWTF) Burn Units (i.e., Thermal Treatment Unit and Burn Pan); (2) One area upwind of the Burn Units and Detonation Pad; (3) Two areas downwind of the EWTF Detonation Pad; and (4) Three areas unaffected (representing ambient conditions) by EWTF operations approximately 7000-8000 feet upwind of the facility. The purpose of the sampling in areas 1, 2, and 3 is to detect if operations cause increases in concentrations of materials downwind of the Burn Units or downwind of the Detonation Pad. The purpose of the sampling in area 4 is to determine if previously developed background screening levels can be applied to EWTF operations. A 20 foot diameter circle will define each sample area. Soil samples will be obtained from four random locations inside each 20 foot circle. The samples will be obtained immediately below the surface, free of any organic matter (e.g., roots) and other surface and subsurface material (e.g., rocks) that is not conducive to analysis. The random identification of four discrete sample locations in each circle will allow the variability between sample locations and areas, if present, …
Date: December 13, 2007
Creator: Terusaki, S
Object Type: Report
System: The UNT Digital Library
University Research Program in Robotics - "Technologies for Micro-Electrical-Mechanical Systems in directed Stockpile Work (DSW) Radiation and Campaigns", Final Technical Annual Report, Project Period 9/1/06 - 8/31/07 (open access)

University Research Program in Robotics - "Technologies for Micro-Electrical-Mechanical Systems in directed Stockpile Work (DSW) Radiation and Campaigns", Final Technical Annual Report, Project Period 9/1/06 - 8/31/07

The University Research Program in Robotics (URPR) is an integrated group of universities performing fundamental research that addresses broad-based robotics and automation needs of the NNSA Directed Stockpile Work (DSW) and Campaigns. The URPR mission is to provide improved capabilities in robotics science and engineering to meet the future needs of all weapon systems and other associated NNSA/DOE activities.
Date: December 13, 2007
Creator: Tulenko, James S. & Crane, Carl D.
Object Type: Report
System: The UNT Digital Library
Adsorption and Precipitation of Aqueous Zn(II) on Hematite Nano- and Microparticles (open access)

Adsorption and Precipitation of Aqueous Zn(II) on Hematite Nano- and Microparticles

As part of a study of the effect of particle size on reactivity of hematite to aqueous metal ions, the sorption of Zn(II) on hematite nanoparticles and microparticles was examined over a wide range of Zn(II) concentrations using Zn K-edge EXAFS. When reacted with nanoparticles at pH 5.5 and low Zn(II) sorption densities (0.04 {le} {Lambda} < 2.76 imol/m{sup 2}), Zn(II) formed five-coordinated or a mixture of four- and six-coordinated surface complexes with an average Zn-O distance of 2.04({+-}0.02){angstrom}. At pH 5.5 and high Zn(II) sorption densities (2.76 {ge} {Lambda} {le} 3.70 mol/m{sup 2}), formation of surface precipitates is suggested based on the presence of second-shell Zn and multiple scattering features in the Fourier transform (FT) of the EXAFS spectra. EXAFS fitting of these high {Lambda} samples yielded an average first-shell Zn-O distance of 2.10({+-}0.02){angstrom}, with second-shell Zn-Fe and Zn-Zn distances of 3.23({+-}0.03){angstrom} and 3.31({+-}0.03){angstrom}, respectively. Qualitative comparison between the EXAFS spectra of these sorption samples and that of amorphous zinc hydroxide and Zn-bearing hydrotalcite indicates the development of surface precipitates with increasing {Lambda}. EXAFS spectra of Zn(II) sorbed on hematite microparticles under similar experimental conditions showed no evidence for surface precipitates even at the highest Zn surface coverage ({Lambda} …
Date: December 13, 2006
Creator: Ha, Juyong; /Stanford U., Geo. Environ. Sci.; Farges, Francois; /Stanford U., Geo. Environ. Sci. /Museum Nat. Hist., Paris; Brown, Gordon E., Jr. & /SLAC, SSRL
Object Type: Article
System: The UNT Digital Library
Adsorption Mechanisms of Trivalent Gold onto Iron Oxy-Hydroxides: From the Molecular Scale to the Model (open access)

Adsorption Mechanisms of Trivalent Gold onto Iron Oxy-Hydroxides: From the Molecular Scale to the Model

Gold is a highly valuable metal that can concentrate in iron-rich exogenetic horizons such as laterites. An improved knowledge of the retention mechanisms of gold onto highly reactive soil components such as iron oxyhydroxides is therefore needed to better understand and predict the geochemical behavior of this element. In this study, we use EXAFS information and titration experiments to provide a realistic thermochemical description of the sorption of trivalent gold onto iron oxy-hydroxides. Analysis of Au L{sub III}-edge XAFS spectra shows that aqueous Au(III) adsorbs from chloride solutions onto goethite surfaces as inner-sphere square-planar complexes (Au(III)(OH,Cl){sub 4}), with dominantly OH ligands at pH > 6 and mixed OH/Cl ligands at lower pH values. In combination with these spectroscopic results, Reverse Monte Carlo simulations were used to constraint the possible sorption sites on the surface of goethite. Based on this structural information, we calculated sorption isotherms of Au(III) on Fe oxy-hydroxides surfaces, using the CD-MUSIC (Charge Distribution--Multi Site Complexation) model. The various Au(III)-sorbed species were identified as a function of pH, and the results of these EXAFS+CD-MUSIC models are compared with titration experiments. The overall good agreement between the predicted and measured structural models shows the potential of this combined approach …
Date: December 13, 2006
Creator: Cances, Benjamin; Benedetti, Marc; Farges, Francois; Brown, Gordon E., Jr. & /Stanford U., Geo. Environ. Sci. /SLAC, SSRL
Object Type: Article
System: The UNT Digital Library
ANALYSIS RESULTS FOR BUILDING 241 702-AZ A TRAIN (open access)

ANALYSIS RESULTS FOR BUILDING 241 702-AZ A TRAIN

This report presents the analyses results for three samples obtained under RPP-PLAN-28509, Sampling and Analysis Plan for Building 241 702-AZ A Train. The sampling and analysis was done in response to problem evaluation request number PER-2004-6139, 702-AZ Filter Rooms Need Radiological Cleanup Efforts.
Date: December 13, 2006
Creator: JB, DUNCAN; JM, FRYE; CA, COOKE; SW, LI & FJ, BROCKMAN
Object Type: Report
System: The UNT Digital Library
Chrysolcolla Redefined as Spertiniite (open access)

Chrysolcolla Redefined as Spertiniite

XAFS and {mu}-XAFS spectra were collected at the Cu K-edge for seven chrysocolla samples (Peru, USA, and Congo). The results suggest that the local structure around Cu is similar to that in Cu(OH){sub 2} (spertiniite). Cu-L{sub 3} STXM imaging and spectroscopy confirm that the chrysocolla samples examined here consist of mesoscopic Cu(II)-rich domains surrounded by Si-rich domains (in agreement with results from infra-red spectroscopy). Hence, we suggest that chrysocolla, which is generally considered to be orthorhombic with composition (Cu,Al){sub 2}H{sub 2}Si{sub 2}O{sub 5}(OH){sub 4} {center_dot} nH{sub 2}O, is in actually a mesoscopic assemblage composed dominantly of spertiniite (Cu(OH){sub 2}), water and amorphous silica (SiO{sub 2}).
Date: December 13, 2006
Creator: Farges, Francois; /Museum Nat. Hist., Paris /Stanford U., Geo. Environ. Sci.; Benzerara, Karim; /Paris U., VI-VII, LMCP; Brown, Gordon E., Jr. & /Stanford U., Geo. Environ. Sci. /SLAC, SSRL
Object Type: Article
System: The UNT Digital Library
Coupling of Realistic Real Estimates with Genomics for Assessing Contaminant Attenuation and Long-Term Plume Containment (open access)

Coupling of Realistic Real Estimates with Genomics for Assessing Contaminant Attenuation and Long-Term Plume Containment

Coupling of Realistic Real Estimates with Genomics for Assessing Contaminant Attenuation and Long-Term Plume Containment
Date: December 13, 2006
Creator: Crawford, Roland L.
Object Type: Report
System: The UNT Digital Library
Creating an educational consortium to support the recruitment and retention of expertise for the nuclear weapons complex (open access)

Creating an educational consortium to support the recruitment and retention of expertise for the nuclear weapons complex

From FY 02-05 IAC has been a part of the DOE Advanced Fuel Cycle Initiative and its predecessor organization Advanced Accelerator Applications. In the IAC program effort has been divided into three parts; Student Research, Accelerator Driven Nuclear Research and Materials Science. Within the three parts specific research and development activities have been undertaken in Student Research, which supported undergraduate and graduate students, post-docs, engineering staff, program administration, project infrastructure, visiting and summer faculty appointments, visiting scientists, and support of students and faculty at the University of Michigan, Texas A&M University, University of Texas and UNLV; Accelerator Driven Nuclear Research included the use of electron accelerators to study driven sub-critical nuclear systems (ADS) and to provide practical methods of monitoring and assaying nuclear materials for accountancy in non proliferation applications (Materials Accountability and Control, MA&C); and Materials Science research at IAC supported all AFC national technical areas.
Date: December 13, 2006
Creator: Harmon, Frank, Wells, Douglas, P., Hunt, Alan, Beller, Denis
Object Type: Report
System: The UNT Digital Library
Direct Mediation of Meta-Stable Supersymmetry Breaking (open access)

Direct Mediation of Meta-Stable Supersymmetry Breaking

The supersymmetric SU(N{sub c}) Yang-Mills theory coupled to NF matter fields in the fundamental representation has meta-stable vacua with broken supersymmetry when N{sub C} < N{sub F} < 3/2 N{sub C}. By gauging the flavor symmetry, this model can be coupled directly to the standard model. We show that it is possible to make a slight deformation to the model so that gaugino masses are generated and the Landau pole problem can be avoided. The deformed model has simple realizations on intersecting branes in string theory, where various features of the meta-stable vacua are encoded geometrically as brane configurations.
Date: December 13, 2006
Creator: Kitano, Ryuichiro; Ooguri, Hirosi & Ookouchi, Yutaka
Object Type: Report
System: The UNT Digital Library
Discovery of Unusual Minerals in Paleolithic Black Pigments from Lascaux (France) and Ekain (Spain) (open access)

Discovery of Unusual Minerals in Paleolithic Black Pigments from Lascaux (France) and Ekain (Spain)

Analyses of archaeological materials aim to rediscover the know-how of Prehistoric people by determining the nature of the painting matter, its preparation mode, and the geographic origin of its raw materials. This study deals with identification of manganese oxides in black pigments by micro-XANES (X-ray absorption near-edge structure) based on previous TEM (transmission electron microscopy) studies. Complex mixtures of the manganese oxides studied are present in some of mankind's oldest known paintings, namely those from the caves of Lascaux (Dordogne, France) and Ekain (Basque country, Spain). Scarce manganese oxide minerals, including groutite, hausmannite, and manganite, were found for the first time in Paleolithic art at these archaeological sites. Because there are no known deposits of such minerals in these areas, more distant origins and trade routes are inferred. The closest known Mn-rich geological province for Lascaux is the central Pyrenees, which is {approx} 250 km from the Dordogne area.
Date: December 13, 2006
Creator: Chalmin, E.; Farges, F.; Vignaud, C.; Susini, J.; Menu, M. & Brown, G. E., Jr.
Object Type: Article
System: The UNT Digital Library
Electrochromic Windows: Advanced Processing Technology (open access)

Electrochromic Windows: Advanced Processing Technology

This project addresses the development of advanced fabrication capabilities for energy saving electrochromic (EC) windows. SAGE EC windows consist of an inorganic stack of thin films deposited onto a glass substrate. The window tint can be reversibly changed by the application of a low power dc voltage. This property can be used to modulate the amount of light and heat entering buildings (or vehicles) through the glazings. By judicious management of this so-called solar heat gain, it is possible to derive significant energy savings due to reductions in heating lighting, and air conditioning (HVAC). Several areas of SAGE’s production were targeted during this project to allow significant improvements to processing throughput, yield and overall quality of the processing, in an effort to reduce the cost and thereby improve the market penetration. First, the overall thin film process was optimized to allow a more robust set of operating points to be used, thereby maximizing the yield due to the thin film deposition themselves. Other significant efforts aimed at improving yield were relating to implementing new procedures and processes for the manufacturing process, to improve the quality of the substrate preparation, and the quality of the IGU fabrication. Furthermore, methods for reworking …
Date: December 13, 2006
Creator: Sage Electrochromics, Inc.
Object Type: Report
System: The UNT Digital Library
EXAFS Signatures of Structural Zn at Trace Levels in Layered Minerals (open access)

EXAFS Signatures of Structural Zn at Trace Levels in Layered Minerals

Many in situ XAFS studies have shown that zinc incorporated in layered minerals is a major form of zinc in Zn-contaminated soils. Quantitative information on the local structural environment(s) and ordering of Zn in these minerals is required to better understand its behavior in soils. In this study, EXAFS spectroscopy was used to assess the structural environment of zinc incorporated at trace levels (40 ppm to 4,000 ppm) within the octahedral sheets of various natural and synthetic layered minerals. Results indicate that EXAFS data analyzed using ab initio FEFF calculations (FEFF 8.10) can unambiguously distinguish between zinc incorporation within the octahedral sheet of dioctahedral versus trioctahedral layered minerals and can determine the distribution (random or ordered) of zinc cations within the octahedral sheets of these minerals.
Date: December 13, 2006
Creator: Juillot, Farid; Morin, Guillaume; Hazemann, Jean-Louis; Proux, Olivier; Belin, Stephanie; Briois, Valerie et al.
Object Type: Article
System: The UNT Digital Library
High Availability Electronics Standards (open access)

High Availability Electronics Standards

Availability modeling of the proposed International Linear Collider (ILC) predicts unacceptably low uptime with current electronics systems designs. High Availability (HA) analysis is being used as a guideline for all major machine systems including sources, utilities, cryogenics, magnets, power supplies, instrumentation and controls. R&D teams are seeking to achieve total machine high availability with nominal impact on system cost. The focus of this paper is the investigation of commercial standard HA architectures and packaging for Accelerator Controls and Instrumentation. Application of HA design principles to power systems and detector instrumentation are also discussed.
Date: December 13, 2006
Creator: Larsen, R.S.
Object Type: Article
System: The UNT Digital Library
The Injection Laser System on the National Ignition Facility (open access)

The Injection Laser System on the National Ignition Facility

The National Ignition Facility (NIF) is currently the largest and most energetic laser system in the world. The main amplifiers are driven by the Injection Laser System comprised of the master oscillators, optical preamplifiers, temporal pulse shaping and spatial beam formatting elements and injection diagnostics. Starting with two fiber oscillators separated by up to a few angstroms, the pulse is phase modulated to suppress SBS and enhance spatial smoothing, amplified, split into 48 individual fibers, and then temporally shaped by an arbitrary waveform generator. Residual amplitude modulation induced in the preamplifiers from the phase modulation is also precompensated in the fiber portion of the system before it is injected into the 48 pre-amplifier modules (PAMs). Each of the PAMs amplifies the light from the 1 nJ fiber injection up to the multi-joule level in two stages. Between the two stages the pre-pulse is suppressed by 60 dB and the beam is spatially formatted to a square aperture with precompensation for the nonuniform gain profile of the main laser. The input sensor package is used to align the output of each PAM to the main laser and acquire energy, power, and spatial profiles for all shots. The beam transport sections split …
Date: December 13, 2006
Creator: Bowers, Mark; Burkhart, Scott; Cohen, Simon; Erbert, Gaylen; Heebner, John; Hermann, Mark et al.
Object Type: Article
System: The UNT Digital Library