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Magnet R&D for the US LHC Accelerator Research Program (LARP) (open access)

Magnet R&D for the US LHC Accelerator Research Program (LARP)

In 2004, the US DOE established the LHC Accelerator Research Program (LARP) with the goal of developing a technology base for future upgrades of the LHC. The focus of the magnet program, which is a collaboration of three US laboratories, BNL, FNAL and LBNL, is on development of high gradient quadrupoles using Nb{sub 3}Sn superconductor. Other program components address issues regarding magnet design, radiation-hard materials, long magnet scale-up, quench protection, fabrication techniques and conductor and cable R&D. This paper presents an overall view of the program with emphasis on the current quadrupole project and outlines the long-term goals of the program.
Date: June 1, 2006
Creator: Gourlay, S. A.; Ambrosio, G.; Andreev, N.; Anerella, M.; Barzi, E.; Bossert, R. et al.
System: The UNT Digital Library
Stochastic Transport Modeling of Resonant Magnetic Perturbations in DIII-D (open access)

Stochastic Transport Modeling of Resonant Magnetic Perturbations in DIII-D

Three-dimensional two-fluid simulations of heat transport due to resonant magnetic perturbations of tokamaks have been computed by coupling the TRIP3D field line tracing code to the E3D edge transport code. The predicted electron temperature contours follow the new separatrix represented by the perturbed invariant manifold structure of the X-point in qualitative agreement with X-point TV observations. However, preliminary modeling predicts that the resulting stochastic heat transport is greater than that measured in low-collisionality ELM suppression experiments in DIII-D H-mode plasmas. While improved determination of transport coefficients is definitely required, possible explanations include plasma screening of resonant perturbations, invalid treatment of the edge as a fluid, or insufficient understanding of stochastic heat transport.
Date: June 1, 2006
Creator: Joseph, I.; Moyer, R. A.; Evans, T. E.; Schaffer, M. J.; Runov, A. M.; Schneider, R. et al.
System: The UNT Digital Library
Long Pulse High Performance Plasma Scenario Development for the National Spherical Torus Experiment (open access)

Long Pulse High Performance Plasma Scenario Development for the National Spherical Torus Experiment

The National Spherical Torus Experiment [Ono et al., Nucl. Fusion, 44, 452 (2004)] is targeting long pulse high performance, noninductive sustained operations at low aspect ratio, and the demonstration of nonsolenoidal startup and current rampup. The modeling of these plasmas provides a framework for experimental planning and identifies the tools to access these regimes. Simulations based on neutral beam injection (NBI)-heated plasmas are made to understand the impact of various modifications and identify the requirements for (1) high elongation and triangularity, (2) density control to optimize the current drive, (3) plasma rotation and/or feedback stabilization to operate above the no-wall limit, and (4) electron Bernstein waves (EBW) for off-axis heating/current drive (H/CD). Integrated scenarios are constructed to provide the transport evolution and H/CD source modeling, supported by rf and stability analyses. Important factors include the energy confinement, Zeff, early heating/H mode, broadening of the NBI-driven current profile, and maintaining q(0) and qmin>1.0. Simulations show that noninductive sustained plasmas can be reached at IP=800 kA, BT=0.5 T, 2.5, N5, 15%, fNI=92%, and q(0)>1.0 with NBI H/CD, density control, and similar global energy confinement to experiments. The noninductive sustained high plasmas can be reached at IP=1.0 MA, BT=0.35 T, 2.5, N9, 43%, …
Date: January 1, 2006
Creator: Kessel, C.E.; Bell, R.E.; Bell, M.G.; Gates, D.A. & Harvey, R.W.
System: The UNT Digital Library
Comparison groups on bills: Automated, personalized energy information (open access)

Comparison groups on bills: Automated, personalized energy information

A program called ``Innovative Billing?? has been developed to provide individualized energy information for a mass audience?the entireresidential customer base of an electric or gas utility. Customers receive a graph on the bill that compares that customer?s consumption with othersimilar customers for the same month. The program aims to stimulate customers to make ef?ciency improvements. To group as many as severalmillion customers into small ``comparison groups??, an automated method must be developed drawing solely from the data available to the utility.This paper develops and applies methods to compare the quality of resulting comparison groups.A data base of 114,000 customers from a utility billing system was used to evaluate Innovative Billing comparison groups, comparing fouralternative criteria: house characteristics (?oor area, housing type, and heating fuel); street; meter read route; billing cycle. Also, customers wereinterviewed to see what forms of comparison graphs made most sense and led to fewest errors of interpretation. We ?nd that good qualitycomparison groups result from using street name, meter book, or multiple house characteristics. Other criteria we tested, such as entire cycle, entiremeter book, or single house characteristics such as ?oor area, resulted in poor quality comparison groups. This analysis provides a basis forchoosing comparison groups based …
Date: July 1, 2006
Creator: Iyer, Maithili; Kempton, Willett & Payne, Christopher
System: The UNT Digital Library
Comparative Genome Analysis in the Integrated Microbial Genomes (IMG) System (open access)

Comparative Genome Analysis in the Integrated Microbial Genomes (IMG) System

Comparative genome analysis is critical for the effectiveexploration of a rapidly growing number of complete and draft sequencesfor microbial genomes. The Integrated Microbial Genomes (IMG) system(img.jgi.doe.gov) has been developed as a community resource thatprovides support for comparative analysis of microbial genomes in anintegrated context. IMG allows users to navigate the multidimensionalmicrobial genome data space and focus their analysis on a subset ofgenes, genomes, and functions of interest. IMG provides graphicalviewers, summaries and occurrence profile tools for comparing genes,pathways and functions (terms) across specific genomes. Genes can befurther examined using gene neighborhoods and compared with sequencealignment tools.
Date: March 1, 2006
Creator: Kyrpides, Nikos C. & Markowitz, Victor M.
System: The UNT Digital Library
Modeling the Integrated Performance of Dispersion and Monolithic U-Mo Based Fuels (open access)

Modeling the Integrated Performance of Dispersion and Monolithic U-Mo Based Fuels

The evaluation and prediction of integrated fuel performance is a critical component of the Reduced Enrichment for Research and Test Reactors (RERTR) program. The PLATE code is the primary tool being developed and used to perform these functions. The code is being modified to incorporate the most recent fuel/matrix interaction correlations as they become available for both aluminum and aluminum/silicon matrices. The code is also being adapted to treat cylindrical and square pin geometries to enhance the validation database by including the results gathered from various international partners. Additional modeling work has been initiated to evaluate the thermal and mechanical performance requirements unique to monolithic fuels during irradiation.
Date: October 1, 2006
Creator: Wachs, Daniel M.; Burkes, Douglas E.; Hayes, Steven L.; Moore, Karen; Miller, Greg; Hofman, Gerard et al.
System: The UNT Digital Library
The Role of Emerging Technologies in Improving Energy Efficiency:Examples from the Food Processing Industry (open access)

The Role of Emerging Technologies in Improving Energy Efficiency:Examples from the Food Processing Industry

None
Date: May 1, 2006
Creator: Lung, Robert Bruce; Masanet, Eric & McKane, Aimee
System: The UNT Digital Library
In Vivo Enhancer Analysis Chromosome 16 Conserved NoncodingSequences (open access)

In Vivo Enhancer Analysis Chromosome 16 Conserved NoncodingSequences

The identification of enhancers with predicted specificitiesin vertebrate genomes remains a significant challenge that is hampered bya lack of experimentally validated training sets. In this study, weleveraged extreme evolutionary sequence conservation as a filter toidentify putative gene regulatory elements and characterized the in vivoenhancer activity of human-fish conserved and ultraconserved1 noncodingelements on human chromosome 16 as well as such elements from elsewherein the genome. We initially tested 165 of these extremely conservedsequences in a transgenic mouse enhancer assay and observed that 48percent (79/165) functioned reproducibly as tissue-specific enhancers ofgene expression at embryonic day 11.5. While driving expression in abroad range of anatomical structures in the embryo, the majority of the79 enhancers drove expression in various regions of the developingnervous system. Studying a set of DNA elements that specifically droveforebrain expression, we identified DNA signatures specifically enrichedin these elements and used these parameters to rank all ~;3,400human-fugu conserved noncoding elements in the human genome. The testingof the top predictions in transgenic mice resulted in a three-foldenrichment for sequences with forebrain enhancer activity. These datadramatically expand the catalogue of in vivo-characterized human geneenhancers and illustrate the future utility of such training sets for avariety of iological applications including decoding the regulatoryvocabulary of …
Date: February 1, 2006
Creator: Pennacchio, Len A.; Ahituv, Nadav; Moses, Alan M.; Nobrega,Marcelo; Prabhakar, Shyam; Shoukry, Malak et al.
System: The UNT Digital Library
In Vivo Characterization of Human APOA5 Haplotypes (open access)

In Vivo Characterization of Human APOA5 Haplotypes

Increased plasma triglycerides concentrations are an independent risk factor for cardiovascular disease. Numerous studies support a reproducible genetic association between two minor haplotypes in the human apolipoprotein A5 gene (APOA5) and increased plasma triglyceride concentrations. We thus sought to investigate the effect of these minor haplotypes (APOA5*2 and APOA5*3) on ApoAV plasma levels through the precise insertion of single-copy intact APOA5 haplotypes at a targeted location in the mouse genome. While we found no difference in the amount of human plasma ApoAV in mice containing the common APOA5*1 and minor APOA5*2 haplotype, the introduction of the single APOA5*3 defining allele (19W) resulted in 3-fold lower ApoAV plasma levels consistent with existing genetic association studies. These results indicate that S19W polymorphism is likely to be functional and explain the strong association of this variant with plasma triglycerides supporting the value of sensitive in vivo assays to define the functional nature of human haplotypes.
Date: October 1, 2006
Creator: Ahituv, Nadav; Akiyama, Jennifer; Chapman-Helleboid, Audrey; Fruchart, Jamila & Pennacchio, Len A.
System: The UNT Digital Library
Heavy Flavor Measurements at RHIC in the Near Future (open access)

Heavy Flavor Measurements at RHIC in the Near Future

We discuss the recent results on open charm measurements at RHIC. The heavy flavor upgrade program for both PHENIX and STAR experiments are briefly discussed. The completion of the program will yield important information on light flavor thermalization of the partonic matter created in high-energy nuclear collisions at RHIC. A new era of RHIC is ahead of us with the progress of the upgrade program.
Date: December 1, 2006
Creator: Xu, Nu
System: The UNT Digital Library
GeV electron beams from a laser-plasma accelerator (open access)

GeV electron beams from a laser-plasma accelerator

High-quality electron beams with up to 1 GeV energy havebeen generated by a laser-driven plasma-based accelerator by guiding a 40TW peak power laser pulse in a 3.3 cm long gas-filled capillary dischargewaveguide.
Date: October 1, 2006
Creator: Schroeder, C. B.; Tóth, Cs.; Nagler, B.; Gonsalves, A. J.; Nakamura, K.; Geddes, C. G. R. et al.
System: The UNT Digital Library
Transport and Deposition of 13c From Methane Injection into Detached H-Mode Plasmas in DIII-D (open access)

Transport and Deposition of 13c From Methane Injection into Detached H-Mode Plasmas in DIII-D

Experiments are described which examine the transport and deposition of carbon entering the main plasma scrape-off layer in DIII-D. {sup 13}CH{sub 4} was injected from a toroidally symmetric source into the crown of lower single-null detached ELMy H-mode plasmas. {sup 13}C deposition, mapped by nuclear reaction analysis of tiles, was high at the inner divertor but absent at the outer divertor, as found previously for low density L-mode plasmas. This asymmetry indicates that ionized carbon is swept towards the inner divertor by a fast flow in the scrape-off layer. In the private flux region between inner and outer strike points, carbon deposition was low for L-mode but high for the H-mode plasmas. OEDGE modeling reproduces observed deposition patterns and indicates that neutral carbon dominates deposition in the divertor from detached H-mode plasmas.
Date: June 1, 2006
Creator: Wampler, W. R.; McLean, A. G.; Allen, S. L.; Brooks, N. H.; Elder, J. D.; Fenstermacher, M. E. et al.
System: The UNT Digital Library
Low energy spread 100 MeV-1 GeV electron bunches from laserwakefiel d acceleration at LOASIS (open access)

Low energy spread 100 MeV-1 GeV electron bunches from laserwakefiel d acceleration at LOASIS

Experiments at the LOASIS laboratory of LBNL recentlydemonstrated production of 100 MeV electron beams with low energy spreadand low divergence from laser wakefield acceleration. The radiationpressure of a 10 TW laser pulse guided over 10 diffraction ranges by aplasma density channel was used to drive an intense plasma wave(wakefield), producing acceleration gradients on the order of 100 GV/m ina mm-scale channel. Beam energy has now been increased from 100 to 1000MeV by using a cm-scale guiding channel at lower density, driven by a 40TW laser, demonstrating the anticipated scaling to higher beam energies.Particle simulations indicate that the low energy spread beams wereproduced from self trapped electrons through the interplay of trapping,loading, and dephasing. Other experiments and simulations are alsounderway to control injection of particles into the wake, and henceimprove beam quality and stability further.
Date: August 1, 2006
Creator: Geddes, C. G. R.; Esarey, E.; Michel, P.; Nagler, B.; Nakamura, K.; Plateau, G. R. et al.
System: The UNT Digital Library
Special Issue On Estimation Of Baselines And Leakage In CarbonMitigation Forestry Projects (open access)

Special Issue On Estimation Of Baselines And Leakage In CarbonMitigation Forestry Projects

There is a growing acceptance that the environmentalbenefits of forests extend beyond traditional ecological benefits andinclude the mitigation of climate change. Interest in forestry mitigationactivities has led to the inclusion of forestry practices at the projectlevel in international agreements. Climate change activities place newdemands on participating institutions to set baselines, establishadditionality, determine leakage, ensure permanence, and monitor andverify a project's greenhouse gas benefits. These issues are common toboth forestry and other types of mitigation projects. They demandempirical evidence to establish conditions under which such projects canprovide sustained long term global benefits. This Special Issue reportson papers that experiment with a range of approaches based on empiricalevidence for the setting of baselines and estimation of leakage inprojects in developing Asia and Latin America.
Date: June 1, 2006
Creator: Sathaye, Jayant A. & Andrasko, Kenneth
System: The UNT Digital Library
Clean Slate Environmental Remediation DSA for 10 CFR 830 Compliance (open access)

Clean Slate Environmental Remediation DSA for 10 CFR 830 Compliance

Clean Slate Sites II and III are scheduled for environmental remediation (ER) to remove elevated levels of radionuclides in soil. These sites are contaminated with legacy remains of non-nuclear yield nuclear weapons experiments at the Nevada Test Site, that involved high explosive, fissile, and related materials. The sites may also hold unexploded ordnance (UXO) from military training activities in the area over the intervening years. Regulation 10 CFR 830 (Ref. 1) identifies DOE-STD-1120-98 (Ref. 2) and 29 CFR 1910.120 (Ref. 3) as the safe harbor methodologies for performing these remediation operations. Of these methodologies, DOE-STD-1120-98 has been superseded by DOE-STD-1120-2005 (Ref. 4). The project adopted DOE-STD-1120-2005, which includes an approach for ER projects, in combination with 29 CFR 1910.120, as the basis documents for preparing the documented safety analysis (DSA). To securely implement the safe harbor methodologies, we applied DOE-STD-1027-92 (Ref. 5) and DOE-STD-3009-94 (Ref. 6), as needed, to develop a robust hazard classification and hazards analysis that addresses non-standard hazards such as radionuclides and UXO. The hazard analyses provided the basis for identifying Technical Safety Requirements (TSR) level controls. The DOE-STD-1186-2004 (Ref. 7) methodology showed that some controls warranted elevation to Specific Administrative Control (SAC) status. In addition to …
Date: August 1, 2006
Creator: James L. Traynor, Stephen L. Nicolosi, Michael L. Space, Louis F. Restrepo
System: The UNT Digital Library
OEDGE Modeling of the DIII-D H-Mode 13CH4 Puffing Experiment (open access)

OEDGE Modeling of the DIII-D H-Mode 13CH4 Puffing Experiment

Use of carbon in tokamaks leads to a serious tritium retention issue due to co-deposition. To further investigate the processes involved, a detached ELMy H-mode (6.5 MW NBI) experiment was performed on DIII-D in which {sup 13}CH{sub 4} was puffed into the main vessel through the toroidally symmetric pumping plenum at the top of lower single-null discharges. Subsequently, the {sup 13}C content of tiles taken from the vessel wall was measured. The interpretive OEDGE code was used to model the results. The {sup 13}C deposition pattern could be reproduced, in general shape and magnitude, by assuming in the code the existence of a parallel flow and a radial pinch in the scrape-off layer. Parallel flows of Mach {approx} 0.3 toward the inner divertor and a radial pinch {approx}10 to 20 m/s (+ R-direction) were found to yield {sup 13}C deposition comparable to the experiment.
Date: June 1, 2006
Creator: Elder, J. D.; McLean, A. G.; Stangeby, P. C.; Allen, S. L.; Boedo, J. C.; Bray, B. D. et al.
System: The UNT Digital Library
MCNP Comparison With Point Source Measurements From a Portable HPGe System (open access)

MCNP Comparison With Point Source Measurements From a Portable HPGe System

The Ortec trans-SPEC is a portable gamma ray spectrometer which is approximately 10.4 kg in total weight and 37 cm × 16 cm × 32 cm in overall size It utilizes a P-type 50 mm diameter and 30 mm height coaxial HPGe detector and has more than 3 hours of battery life when fully charged. This paper details the experimental agreement found for one of these detector units and that of MCNP5 [1] calculations. The purpose of carrying out this work is to evaluate the potential utility of the spectrometer for emergency response (consequence management) applications.
Date: January 1, 2006
Creator: Hayes, Robert
System: The UNT Digital Library
Fox-2 Splicing Factor Binds to a Conserved Intron Motif to PromoteInclusion of Protein 4.1R Alternative Exon 16 (open access)

Fox-2 Splicing Factor Binds to a Conserved Intron Motif to PromoteInclusion of Protein 4.1R Alternative Exon 16

Activation of protein 4.1R exon 16 (E16) inclusion during erythropoiesis represents a physiologically important splicing switch that increases 4.1R affinity for spectrin and actin. Previous studies showed that negative regulation of E16 splicing is mediated by the binding of hnRNP A/B proteins to silencer elements in the exon and that downregulation of hnRNP A/B proteins in erythroblasts leads to activation of E16 inclusion. This paper demonstrates that positive regulation of E16 splicing can be mediated by Fox-2 or Fox-1, two closely related splicing factors that possess identical RNA recognition motifs. SELEX experiments with human Fox-1 revealed highly selective binding to the hexamer UGCAUG. Both Fox-1 and Fox-2 were able to bind the conserved UGCAUG elements in the proximal intron downstream of E16, and both could activate E16 splicing in HeLa cell co-transfection assays in a UGCAUG-dependent manner. Conversely, knockdown of Fox-2 expression, achieved with two different siRNA sequences resulted in decreased E16 splicing. Moreover, immunoblot experiments demonstrate mouse erythroblasts express Fox-2, but not Fox-1. These findings suggest that Fox-2 is a physiological activator of E16 splicing in differentiating erythroid cells in vivo. Recent experiments show that UGCAUG is present in the proximal intron sequence of many tissue-specific alternative exons, and …
Date: March 1, 2006
Creator: Ponthier, Julie L.; Schluepen, Christina; Chen, Weiguo; Lersch,Robert A.; Gee, Sherry L.; Hou, Victor C. et al.
System: The UNT Digital Library
Customer Response to RTP in Competitive Markets: A Study ofNiagara Mohawk's Standard Offer Tariff (open access)

Customer Response to RTP in Competitive Markets: A Study ofNiagara Mohawk's Standard Offer Tariff

Utilizing load, price, and survey data for 119 largecustomers that paid competitively determined hourly electricity pricesannounced the previous day between 2000 and 2004, this study providesinsight into the factors that determine the intensity of price response.Peak and off-peak electricity can be: perfect complements, substitutes,or substitutes where high peak prices cause temporary disconnection fromthe grid, as for some firms with on-site generation. The averageelasticity of substitution is 0.11. Thirty percent of the customers usepeak and off-peak electricity in fixed proportions. The 18 percent withelasticities greater than 0.10 provide 75 percent of the aggregate priceresponse. In contrast to Industrial customers, Commercial/Retail andGovernment/Education customers are more price responsive on hot days andwhen the ratio of peak to off-peak prices is high. Price responsivenessis not substantially reduced when customers operate near peak usage.Diversity of customer circumstances and price response suggest dynamicpricing is suited for some, but not all customers.
Date: June 1, 2006
Creator: Boisvert, Richard N.; Cappers, Peter; Goldman, Charles; Neenan,Bernie & Hopper, Nicole
System: The UNT Digital Library
Meta-Analyses of the Associations of Respiratory Health Effectswith Dampness and Mold in Homes (open access)

Meta-Analyses of the Associations of Respiratory Health Effectswith Dampness and Mold in Homes

The Institute of Medicine (IOM) of the National Academy of Sciences recently completed a critical review of the scientific literature pertaining to the association of indoor dampness and mold contamination with adverse health effects. In this paper, we report the results of quantitative meta-analysis of the studies reviewed in the IOM report. We developed point estimates and confidence intervals (CIs) to summarize the association of several respiratory and asthma-related health outcomes with the presence of dampness and mold in homes. The odds ratios and confidence intervals from the original studies were transformed to the log scale and random effect models were applied to the log odds ratios and their variance. Models were constructed both accounting for the correlation between multiple results within the studies analyzed and ignoring such potential correlation. Central estimates of ORs for the health outcomes ranged from 1.32 to 2.10, with most central estimates between 1.3 and 1.8. Confidence intervals (95%) excluded unity except in two of 28 instances, and in most cases the lower bound of the CI exceeded 1.2. In general, the two meta-analysis methods produced similar estimates for ORs and CIs. Based on the results of the meta-analyses, building dampness and mold are associated …
Date: January 1, 2006
Creator: Fisk, William J.; Lei-Gomez, Quanhong & Mendell, Mark J.
System: The UNT Digital Library
In-situ borehole seismic monitoring of injected CO2 at the FrioSite (open access)

In-situ borehole seismic monitoring of injected CO2 at the FrioSite

The U.S. Dept. of Energy funded Frio Brine Pilot provided an opportunity to test borehole seismic monitoring techniques in a saline formation in southeast Texas. A relatively small amount of CO{sub 2} was injected (about 1600 tons) into a thin injection interval (about 6 m thick at 1500 m depth). Designed tests included time-lapse vertical seismic profile (VSP) and crosswell surveys which investigated the detectability of CO{sub 2} with surface-to-borehole and borehole-to-borehole measurement.
Date: June 1, 2006
Creator: Daley, Thomas M. & Korneev, Valeri A.
System: The UNT Digital Library
Modeling Hydrogeological and Geomenchanical Processes Related toCO2 Injection in a Faulted Multilayer System (open access)

Modeling Hydrogeological and Geomenchanical Processes Related toCO2 Injection in a Faulted Multilayer System

This paper presents a numerical study of coupled hydrological and geomechanical processes during a deep underground injection of supercritical CO{sub 2} in a hypothetical brine aquifer. We consider a multilayer system in which the injection zone is situated below a sequence of caprock and aquifer layers that are intersected by a vertical fault zone. The fault zone consists of highly fractured shale across the first caprock layers that are located just above the injection zone. Initially, the fractured shale zones are considered sealed with minerals, but we allow fractures (and the fractured zones) to open as a result of injection induced reductions in effective stresses. Our results indicate that even when assuming a very sensitive relationship between effective stress and fractured-zone permeability, the injection-induced changes in permeability across are only moderate with largest changes occurring in the first caprock layer, just above the injection zone. As a result, the upward leakage rate remains relatively small and therefore changes in fluid pressure and hydromechanical effects in overlying zones are also relatively small for the case studied in this paper.
Date: January 1, 2006
Creator: Rutqvist, Jonny; Birkholzer, Jens & Tsang, Chin-Fu
System: The UNT Digital Library
Reversible Guest Exchange Mechanisms in Supramolecular Host-Guest Assemblies (open access)

Reversible Guest Exchange Mechanisms in Supramolecular Host-Guest Assemblies

Synthetic chemists have provided a wide array of supramolecular assemblies able to encapsulate guest molecules. The scope of this tutorial review focuses on supramolecular host molecules capable of reversibly encapsulating polyatomic guests. Much work has been done to determine the mechanism of guest encapsulation and guest release. This review covers common methods of monitoring and characterizing guest exchange such as NMR, UV-VIS, mass spectroscopy, electrochemistry, and calorimetry and also presents representative examples of guest exchange mechanisms. The guest exchange mechanisms of hemicarcerands, cucurbiturils, hydrogen-bonded assemblies, and metal-ligand assemblies are discussed. Special attention is given to systems which exhibit constrictive binding, a motif common in supramolecular guest exchange systems.
Date: September 1, 2006
Creator: Pluth, Michael D. & Raymond, Kenneth N.
System: The UNT Digital Library
Optomechanical considerations for the VISAR diagnostic at the National Ignition Facility (NIF) (open access)

Optomechanical considerations for the VISAR diagnostic at the National Ignition Facility (NIF)

The National Ignition Facility (NIF) requires optical diagnostics for measuring shock velocities in shock physics experiments. The velocity interferometer for any reflector measures shock velocities at a location remote to the NIF target chamber. Our team designed two systems, one for a polar port orientation, and the other to accommodate two equatorial ports. The polar-oriented design requires a 48-m optical relay to move the light from inside the target chamber to a separately housed measurement and laser illumination station. The currently operational equatorial design requires a much shorter relay of 21 m. Both designs posed significant optomechanical challenges due to the long optical path length, large quantity of optical elements, and stringent NIF requirements. System design had to tightly control the use of lubricants and materials, especially those inside the vacuum chamber; tolerate earthquakes and radiation; and consider numerous other tolerance, alignment, and steering adjustment issues. To ensure compliance with NIF performance requirements, we conducted a finite element analysis.
Date: September 1, 2006
Creator: Kaufman, Morris I.; Celeste, John R.; Frogget, Brent C.; Lee, Tony L.; GacGowan, Brian J.; Malone, Robert M. et al.
System: The UNT Digital Library