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Intial synchroscan streak camera imaging at the A0 photoinjector
At the Fermilab A0 photoinjector facility, bunch-length measurements of the laser micropulse and the e-beam micropulse have been done in the past with a single-sweep module of the Hamamatsu C5680 streak camera with an intrinsic shot-to-shot trigger jitter of 10 to 20 ps. We have upgraded the camera system with the synchroscan module tuned to 81.25 MHz to provide synchronous summing capability with less than 1.5-ps FWHM trigger jitter and a phase-locked delay box to provide phase stability of {approx}1 ps over 10s of minutes. This allowed us to measure both the UV laser pulse train at 244 nm and the e-beam via optical transition radiation (OTR). Due to the low electron beam energies and OTR signals, we typically summed over 50 micropulses with 1 nC per micropulse. We also did electron beam bunch length vs. micropulse charge measurements to identify a significant e-beam micropulse elongation from 10 to 30 ps (FWHM) for charges from 1 to 4.6 nC. This effect is attributed to space-charge effects in the PC gun as reproduced by ASTRA calculations. Chromatic temporal dispersion effects in the optics were also characterized and will be reported.
Date:
April 1, 2008
Creator:
Lumpkin, A. H. & Ruan, J.
Object Type:
Article
System:
The UNT Digital Library
Hemispheric ultra-wideband antenna.
This report begins with a review of reduced size ultra-wideband (UWB) antennas and the peculiar problems that arise when building a UWB antenna. It then gives a description of a new type of UWB antenna that resolves these problems. This antenna, dubbed the hemispheric conical antenna, is similar to a conventional conical antenna in that it uses the same inverted conical conductor over a ground plane, but it also uses a hemispheric dielectric fill in between the conductive cone and the ground plane. The dielectric material creates a fundamentally new antenna which is reduced in size and much more rugged than a standard UWB conical antenna. The creation of finite-difference time domain (FDTD) software tools in spherical coordinates, as described in SAND2004-6577, enabled this technological advance.
Date:
April 1, 2006
Creator:
Brocato, Robert Wesley
Object Type:
Report
System:
The UNT Digital Library
Search for the Rare Decays B^+ -> mu^+ mu^- K^+, B^0 -> mu^+ mu^- K^*0(892), and B^0_s -> mu^+ mu^- phi at CDF
The authors search for b {yields} s{mu}{sup +}{mu}{sup -} transitions in B meson (B{sup +}, B{sup 0}, or B{sub s}{sup 0}) decays with 924 pb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. They find excesses with significances of 4.5, 2.9, and 2.4 standard deviations in the B{sup +} {yields} {mu}{sup +}{mu}{sup -}K{sup +}, B{sup 0} {yields} {mu}{sup +}{mu}{sup -}K*(892){sup 0}, and B{sub s}{sup 0} {yields} {mu}{sup +}{mu}{sup -}{phi} decay modes, respectively. Using B {yields} J/{psi}h (h - K{sup +}, K*(892){sup 0}, {phi}) decays as normalization channels, they report branching fractions for the previously observed B{sup +} and B{sup 0} decays as normalization channels, they report branching fractions for the previously observed B{sup +} and B{sup 0} decays, {Beta}(B{sup +} {yields} {mu}{sup +}{mu}{sup -}K{sup +}) = (0.59 {+-} 0.15 {+-} 0.04) x 10{sup -6}, and {Beta}(B{sup 0} {yields} {mu}{sup +}{mu}{sup -}K*(892){sup 0}) = (0.81 {+-} 0.30 {+-} 0.10) x 10{sup -6}, where the first uncertainty is statistical, and the second is systematic. These measurements are consistent with the world average results, and are competitive with the best available measurements. They set an upper limit on the relative branching …
Date:
April 1, 2008
Creator:
Aaltonen, T.; Phys., /Helsinki Inst. of; Adelman, J.; /Chicago U., EFI; Akimoto, T.; U., /Tsukuba et al.
Object Type:
Article
System:
The UNT Digital Library
Application and Development of Appropriate Tools and Technologies for Cost-Effective Carbon Sequestration
The Nature Conservancy is participating in a Cooperative Agreement with the Department of Energy (DOE) National Energy Technology Laboratory (NETL) to explore the compatibility of carbon sequestration in terrestrial ecosystems and the conservation of biodiversity. The title of the research project is ''Application and Development of Appropriate Tools and Technologies for Cost-Effective Carbon Sequestration''. The objectives of the project are to: (1) improve carbon offset estimates produced in both the planning and implementation phases of projects; (2) build valid and standardized approaches to estimate project carbon benefits at a reasonable cost; and (3) lay the groundwork for implementing cost-effective projects, providing new testing ground for biodiversity protection and restoration projects that store additional atmospheric carbon. This Technical Progress Report discusses preliminary results of the six specific tasks that The Nature Conservancy is undertaking to answer research needs while facilitating the development of real projects with measurable greenhouse gas reductions. The research described in this report occurred between January 1st and March 31st 2006. The specific tasks discussed include: Task 1: carbon inventory advancements; Task 2: emerging technologies for remote sensing of terrestrial carbon; Task 3: baseline method development; Task 4: third-party technical advisory panel meetings; Task 5: new project feasibility …
Date:
April 1, 2006
Creator:
Stanley, Bill; Gonzalez, Patrick; Brown, Sandra; Henman, Jenny; Murdock, Sarah Woodhouse; Sampson, Neil et al.
Object Type:
Report
System:
The UNT Digital Library
Establishment of an Environmental Control Technology Laboratory with a Circulating Fluidized-Bed Combustion System
This report is to present the progress made on the project ''Establishment of an Environmental Control Technology Laboratory (ECTL) with a Circulating Fluidized-Bed Combustion (CFBC) System'' during the period January 1, 2006 through March 31, 2006. Work was performed on the following activities. First, the fabrication and manufacture of the CFBC Facility were completed. The riser, primary cyclone and secondary cyclone of Circulating Fluidized Bed (CFB) Combustor have been erected. Second, the Mercury Control Workshop and the Grand Opening of Institute for Combustion Science and Environmental Technology (ICSET) were successfully held on February 22 and 23, 2006, respectively. Third, effects of hydrogen chlorine (HCl) and sulfur dioxide (SO{sub 2}) on mercury oxidation were studied in a drop tube reactor. The experimental results from this study are presented in this report. Finally, the proposed work for the next quarter is described in this report.
Date:
April 1, 2006
Creator:
Pan, Wei-Ping; Cao, Yan & Li, Songgeng
Object Type:
Report
System:
The UNT Digital Library
Geothermal Technologies Program: Arizona
A fact sheet describing current and potential geothermal resource use in Arizona.
Date:
April 1, 2006
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
PV Conversion Technologies, Session: OPV, Sensitized, Seed
The NREL Sensitized Solar Cell (SSC) Core Program supports the Solar America Initiative by: (1) targeting new devices and processes for commercialization by 2015 that are less expensive, more efficient, highly reliable, and environmentally benign; (2) collaborating with DOE OS/BES to conduct basic research targeting breakthroughs in key areas, such as ultra-high efficiency and/or ultra-low cost materials and devices.
Date:
April 1, 2008
Creator:
Frank, A. J.
Object Type:
Presentation
System:
The UNT Digital Library
Identifying semiconductors by d.c. ionization conductivity
We describe a method for identifying semiconductor radiationdetector materials based on the mobility of internally generatedelectrons and holes. It was designed for the early stages of exploration,when samples are not available as single crystals, but as crystallinepowders. Samples are confined under pressure in an electric field and theincrease in current resulting from exposure to a high-intensity source of60Co gamma rays (i.e. the ionization current) is measured. We find thatfor known semiconductors the d.c. ionization current depends on voltageaccording to the Hecht equation, and for known insulators the d.c.ionization current is below our detection limits. This shows that themethod can identify semiconductors in spite of significant carriertrapping. Using this method, we have determined that BiOI, PbIF,BiPbO2Cl, BiPbO2Br, BiPbO2I, Bi2GdO4Cl, Pb3O2I2, and Pb5O4I2 aresemiconductors.
Date:
April 1, 2006
Creator:
Derenzo, Stephen E.; Bourret-Courchesne, Edith; James, Floyd J.; Klintenberg, Mattias K.; Porter-Chapman, Yetta; Wang, Jie et al.
Object Type:
Article
System:
The UNT Digital Library
Tonopah Test Range Post-Closure Inspection Annual Report, Tonopah Test Range, Nevada, Calendar Year 2003
This post-closure inspection report provides documentation of the semiannual inspection activities, maintenance and repair activities, and conclusions and recommendations for calendar year 2003 for eight corrective action units located on the Tonopah Test Range, Nevada.
Date:
April 1, 2004
Creator:
United States. National Nuclear Security Administration. Nevada Site Office.
Object Type:
Report
System:
The UNT Digital Library
Rare B and Charm Decays at the Tevatron
None
Date:
April 1, 2008
Creator:
Kuhr, Thomas
Object Type:
Article
System:
The UNT Digital Library
Biocompatible Silver-containing a-C:H and a-C coatings: AComparative Study
Hydrogenated diamond-like-carbon (a-C:H) and hydrogen-free amorphous carbon (a-C) coatings are known to be biocompatible and have good chemical inertness. For this reason, both of these materials are strong candidates to be used as a matrix that embeds metallic elements with antimicrobial effect. In this comparative study, we have incorporated silver into diamond-like carbon (DLC) coatings by plasma based ion implantation and deposition (PBII&D) using methane (CH4) plasma and simultaneously depositing Ag from a pulsed cathodic arc source. In addition, we have grown amorphous carbon - silver composite coatings using a dual-cathode pulsed filtered cathodic-arc (FCA) source. The silver atomic content of the deposited samples was analyzed using glow discharge optical spectroscopy (GDOES). In both cases, the arc pulse frequency of the silver cathode was adjusted in order to obtain samples with approximately 5 at.% of Ag. Surface hardness of the deposited films was analyzed using the nanoindentation technique. Cell viability for both a-C:H/Ag and a-C:/Ag samples deposited on 24-well tissue culture plates has been evaluated.
Date:
April 1, 2007
Creator:
Endrino, Jose Luis; Allen, Matthew; Escobar Galindo, Ramon; Zhang, Hanshen; Anders, Andre & Albella, Jose Maria
Object Type:
Article
System:
The UNT Digital Library
Microstructural Examination to Aid in Understanding Friction Bonding Fabrication Technique for Monolithic Nuclear Fuel
Monolithic nuclear fuel is currently being developed for use in research reactors, and friction bonding (FB) is a technique being developed to help in this fuel’s fabrication. Since both FB and monolithic fuel are new concepts, research is needed to understand the impact of varying FB fabrication parameters on fuel plate characteristics. This thesis research provides insight into the FB process and its application to the monolithic fuel design by recognizing and understanding the microstructural effects of varying fabrication parameters (a) FB tool load, and (b) FB tool face alloy. These two fabrication parameters help drive material temperature during fabrication, and thus the material properties, bond strength, and possible formation of interface reaction layers. This study analyzed temperatures and tool loads measured during those FB processes and examined microstructural characteristics of materials and bonds in samples taken from the resulting fuel plates. This study shows that higher tool load increases aluminum plasticization and forging during FB, and that the tool face alloy helps determine the tool’s heat extraction efficacy. The study concludes that successful aluminum bonds can be attained in fuel plates using a wide range of FB tool loads. The range of tool loads yielding successful uranium-aluminum bonding was …
Date:
April 1, 2008
Creator:
Shropshire, Karen L.
Object Type:
Report
System:
The UNT Digital Library
National Laboratory, Session: Seed Fund
This project supports the Solar America Initiative by: Exploring new ideas that have the potential to make a real difference; and Portfolio of ideas including some that bring a new twist to a proven approach and some that are entirely new.
Date:
April 1, 2008
Creator:
Kurtz, S.
Object Type:
Presentation
System:
The UNT Digital Library
Automatic compensation of antenna beam roll-off in SAR images.
The effects of a non-uniform antenna beam are sometimes visible in Synthetic Aperture Radar (SAR) images. This might be due to near-range operation, wide scenes, or inadequate antenna pointing accuracy. The effects can be mitigated in the SAR image by fitting very a simple model to the illumination profile and compensating the pixel brightness accordingly, in an automated fashion. This is accomplished without a detailed antenna pattern calibration, and allows for drift in the antenna beam alignments.
Date:
April 1, 2006
Creator:
Doerry, Armin Walter
Object Type:
Report
System:
The UNT Digital Library
Philosophy of Mind and the Problem of FreeWill in the Light of Quantum Mechanics.
Arguments pertaining to the mind-brain connection and to the physical effectiveness of our conscious choices have been presented in two recent books, one by John Searle, the other by Jaegwon Kim. These arguments are examined, and it is argued that the difficulties encountered arise from a defective understanding and application of a pertinent part of contemporary science, namely quantum mechanics.
Date:
April 1, 2008
Creator:
Stapp, Henry & Stapp, Henry P
Object Type:
Book
System:
The UNT Digital Library
Ambient-Pressure X-ray Photoelectron Spectroscopy
This workshop focused on the application of ambient pressure X-ray photoelectron spectroscopy (APXPS) to environmental science and catalysis. Pioneering work on APXPS was done in the early 1970's by Hans and Kai Siegbahn et al., who demonstrated that XPS can operate at pressures of up to 1 Torr. A new type of APXPS instrument that utilizes a differentially-pumped electrostatic lens system at the ALS in 2001 increased the pressure limit to above 5 Torr, which opened the door to XPS experiments on water and aqueous solutions at temperatures above the melting point, in equilibrium with the vapor pressure of water. The impact of APXPS on fields such as environmental and atmospheric science as well as heterogeneous catalysis is already visible in numerous high impact publications. Today several other synchrotron facilities around the world have already implemented beam lines for APXPS or planning to do so in the near future. The goal of this workshop (organized by Miquel Salmeron (Molecular Foundry, LBNL), B. Simon Mun (Advanced Light Source, LBNL) and Hendrik Bluhm (Chemical Sciences Division, LBNL)) was to bring together researchers interested in the technique, review its current progress, discuss scientific opportunities and desirable technical improvements as well as consider the …
Date:
April 1, 2008
Creator:
Bluhm, Hendrik; Bluhm, Hendrik; Mun, Bongjin Simon & Salmeron, Miquel
Object Type:
Article
System:
The UNT Digital Library
Measurement of Inclusive Jet Cross Sections in Z/gamma*(->e+e-) + jets Production in ppbar Collisions at s**(1/2) = 1.96 TeV with the CDF Detector
This Ph.D. thesis presents the measurement of inclusive jet cross sections in Z/{gamma}* {yields} e{sup +}e{sup -} events using 1.7 fb{sup -1} of data collected by the upgraded CDF detector during the Run II of the Tevatron. The Midpoint cone algorithm is used to search for jets in the events after identifying the presence of a Z/{gamma}* boson through the reconstruction of its decay products. The measurements are compared to next-to-LO (NLO) pQCD predictions for events with one and two jets in the final state. The perturbative predictions are corrected for the contributions of non-perturbative processes, like the underlying event and the fragmentation of the partons into jets of hadrons. These processes are not described by perturbation theory and must be estimated from phenomenological models. In this thesis, a number of measurements are performed to test different models of underlying event and hadronization implemented in LO plus parton shower Monte Carlo generator programs. Chapter 2 is devoted to the description of the theory of strong interactions and jet phenomenology at hadron colliders. Chapter 3 contains the description of the Tevatron collider and the CDF detector. The analysis is described in detail in Chapter 4. Chapter 5 shows the measurement of …
Date:
April 1, 2008
Creator:
Salto Bauza, Oriol
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
SETP CPV Technology, Session: CPV
This project supports the Solar America Initiative by: (1) Reducing LCOE through--Increased power output from cell, and avenues for lowering of cell cost--substrate recycling; and (2) Establishing reliability by--Determination of cell degradation mechanisms; Integration of design for reliability into future cell development; future-generation cell development; cell reliability; advanced modeling for cell-system integration; basic science supporting cell development; and industry study.
Date:
April 1, 2008
Creator:
Friedman, D.
Object Type:
Presentation
System:
The UNT Digital Library
Study of b-baryons at D0 in Run II of the Tevatron
The study of b-baryons is a unique opportunity at the Tevatron collider, which is the only running accelerator where these particles are expected to be produced. At the beginning of RunII of the Tevatron and after almost 30 years of the discovery of the b quark at Fermilab, the lack of statistics had restricted our knowledge on b-baryons to the observation of the lightest b-baryon, the {Lambda}{sub b}, and to its lifetime measured in decays which did not allow a fully reconstruction of this particle. I present results of the search for b-baryons in the D0 experiment. As part of this program, a precise measurement of the {Lambda}{sub b} lifetime was performed, and the discovery of the {Xi}{sub b}{sup -} resulted from an analysis of 1.3 fb{sup -1} of data collected with the D0 detector during 2002-2006.
Date:
April 1, 2008
Creator:
De La Crus Burelo, Eduard
Object Type:
Report
System:
The UNT Digital Library
Methodology for Validating Building Energy Analysis Simulations
The objective of this report was to develop a validation methodology for building energy analysis simulations, collect high-quality, unambiguous empirical data for validation, and apply the validation methodology to the DOE-2.1, BLAST-2MRT, BLAST-3.0, DEROB-3, DEROB-4, and SUNCAT 2.4 computer programs. This report covers background information, literature survey, validation methodology, comparative studies, analytical verification, empirical validation, comparative evaluation of codes, and conclusions.
Date:
April 1, 2008
Creator:
Judkoff, R.; Wortman, D.; O'Doherty, B. & Burch, J.
Object Type:
Report
System:
The UNT Digital Library
Approaches to Modeling Coupled Flow and Reaction in a 2-D Cementation Experiment
Porosity evolution at reactive interfaces is a key process that governs the evolution and performances of many engineered systems that have important applications in earth and environmental sciences. This is the case, for example, at the interface between cement structures and clays in deep geological nuclear waste disposals. Although in a different transport regime, similar questions arise for permeable reactive barriers used for biogeochemical remediation in surface environments. The COMEDIE project aims at investigating the coupling between transport, hydrodynamics and chemistry when significant variations of porosity occur. The present work focuses on a numerical benchmark used as a design exercise for the future COMEDIE-2D experiment. The use of reactive transport simulation tools like Hytec and Crunch provides predictions of the physico-chemical evolutions that are expected during the future experiments in laboratory. Focus is given in this paper on the evolution during the simulated experiment of precipitate, permeability and porosity fields. A first case is considered in which the porosity is constant. Results obtained with Crunch and Hytec are in relatively good agreement. Differences are attributable to the models of reactive surface area taken into account for dissolution/precipitation processes. Crunch and Hytec simulations taking into account porosity variations are then presented …
Date:
April 1, 2008
Creator:
Steefel, Carl; Cochepin, B.; Trotignon, L.; Bildstein, O.; Steefel, C.; Lagneau, V. et al.
Object Type:
Article
System:
The UNT Digital Library
Heavy-light mesons and chiral symmetry
The chiral structure of heavy-light mesons is explored with a particular focus on the nature of the D{sub sJ} charmed mesons. Theoretical predictions for the hadronic and radiative decays of these mesons are compared to recent experimental data.
Date:
April 1, 2008
Creator:
Bardeen, William A.
Object Type:
Article
System:
The UNT Digital Library
A Preliminary Analysis of the Economics of Using Distributed Energy as a Source of Reactive Power Supply
A major blackout affecting 50 million people in the Northeast United States, where insufficient reactive power supply was an issue, and an increased number of filings made to the Federal Energy Regulatory Commission by generators for reactive power has led to a closer look at reactive power supply and compensation. The Northeastern Massachusetts region is one such area where there is an insufficiency in reactive power compensation. Distributed energy due to its close proximity to loads seems to be a viable option for solving any present or future reactive power shortage problems. Industry experts believe that supplying reactive power from synchronized distributed energy sources can be 2 to 3 times more effective than providing reactive support in bulk from longer distances at the transmission or generation level. Several technology options are available to supply reactive power from distributed energy sources such as small generators, synchronous condensers, fuel cells or microturbines. In addition, simple payback analysis indicates that investments in DG to provide reactive power can be recouped in less than 5 years when capacity payments for providing reactive power are larger than $5,000/kVAR and the DG capital and installation costs are lower than $30/kVAR. However, the current institutional arrangements for …
Date:
April 1, 2006
Creator:
Li, Fangxing; Kueck, John D; Rizy, D Tom & King, Thomas F
Object Type:
Report
System:
The UNT Digital Library
Improving Air Quality with Solar Energy
This fact sheet series highlights how renewable energy and energy efficiency technologies can and are being used to reduce air emissions and meet environmental goals, showcasing case studies and technology-specific topics. This one focus on solar energy technologies.
Date:
April 1, 2008
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library