Compact Superconducting Final Focus Magnet Options for the ILC (open access)

Compact Superconducting Final Focus Magnet Options for the ILC

The QD0 quadrupole, the final focus magnet closest to the Interaction Point (IP) for the ILC 20 mr crossing angle layout, must provide strong focusing yet be adjustable to accommodate collision energy changes for energy scans and low energy calibration running. It must also be compact to allow disrupted beam and Beamstrahlung coming from the IP to pass outside into an independent instrumented beam line that leads to a high-power beam absorber. In designing QD0 we take advantage of recent BNL experience making direct wind superconducting magnets. Here we review important considerations for the present design, report on progress producing a prototype, describe our compact quadrupole concept in greater detail, and relate this work to other ILC design challenges.
Date: March 15, 2006
Creator: Parker, B.; Anerella, M.; Escallier, J.; Harrison, M.; He, P.; Jain, A. K. et al.
Object Type: Article
System: The UNT Digital Library
Comparison of Beam-Based Alignment Algorithms for the ILC (open access)

Comparison of Beam-Based Alignment Algorithms for the ILC

The main linac of the International Linear Collider (ILC) requires more sophisticated alignment techniques than those provided by survey alone. Various Beam-Based Alignment (BBA) algorithms have been proposed to achieve the desired low emittance preservation. Dispersion Free Steering, Ballistic Alignment and the Kubo method are compared. Alignment algorithms are also tested in the presence of an Earth-like stray field.
Date: March 15, 2006
Creator: Smith, J.C.; Gibbons, L.; Patterson, J.R.; Rubin, D.L.; /Cornell U., LEPP; Sagan, D. et al.
Object Type: Article
System: The UNT Digital Library
Comparisons Between Experimental Measurments and Numerical Simulations of Spheromak Formation in SSPX (open access)

Comparisons Between Experimental Measurments and Numerical Simulations of Spheromak Formation in SSPX

Data from a recently installed insertable magnetic probe array in the Sustained Spheromak Physics Experiment (SSPX) [E. B. Hooper et al., Nucl. Fusion 39, 863 (1999)] is compared against NIMROD [C. R. Sovinec et al., J. Comp. Phys. 195, 355 (2004)], a full 3D resistive magnetohydrodynamic code that is used to simulate SSPX plasmas. The experiment probe consists of a linear array of chip inductors arranged in clusters that are spaced every 2 cm, and spans the entire machine radius at the flux conserver midplane. Both the experiment and the numerical simulations show the appearance, shortly after breakdown, of a column with a hollow current profile that precedes magnetic reconnection, a process essential to the formation of closed magnetic flux surfaces. However, there are differences between the experiment and the simulation in how the column evolves after it is formed. These differences are studied to help identify the mechanisms that eventually lead to closed-flux surfaces (azimuthally averaged) and flux amplification, which occur in both the experiment and the simulation.
Date: March 15, 2006
Creator: Romero-Talam?s, C. A.; Hooper, E. B.; Hill, D. N.; Cohen, B. I.; McLean, H. S.; Wood, R. D. et al.
Object Type: Article
System: The UNT Digital Library
Considerations on Beam Quality Control in MIT X-Ray FEL (open access)

Considerations on Beam Quality Control in MIT X-Ray FEL

The x-ray FEL at MIT is one example of a design for a new generation linac-based light source. Such a new machine requires very high quality electron beams. Besides the usual requirements on beam parameters such as emittance, energy spread, peak current, there are new challenges emerging in the design studies, e.g., the arrival timing of electron beam must reach precision below tens of femtoseconds level to ensure the laser seed overlaps the desired sections of electron bunch in the multiple-stage HGHG process. In this paper we report the progress on design optimization towards high quality and low sensitivity beams.
Date: March 15, 2006
Creator: Wang, D.; Graves, W.; Wang, D.; Zwart, T.; Emma, P.; Wu, J. et al.
Object Type: Article
System: The UNT Digital Library
Cooperative Fault Tolerant Distributed Computing (open access)

Cooperative Fault Tolerant Distributed Computing

HARNESS was proposed as a system that combined the best of emerging technologies found in current distributed computing research and commercial products into a very flexible, dynamically adaptable framework that could be used by applications to allow them to evolve and better handle their execution environment. The HARNESS system was designed using the considerable experience from previous projects such as PVM, MPI, IceT and Cumulvs. As such, the system was designed to avoid any of the common problems found with using these current systems, such as no single point of failure, ability to survive machine, node and software failures. Additional features included improved inter-component connectivity, with full support for dynamic down loading of addition components at run-time thus reducing the stress on application developers to build in all the libraries they need in advance.
Date: March 15, 2006
Creator: Fagg, Graham E.
Object Type: Report
System: The UNT Digital Library
CORROSION OF LEAD SHIELDING IN MODEL 9975 PACKAGE (open access)

CORROSION OF LEAD SHIELDING IN MODEL 9975 PACKAGE

Experiments were performed to determine the corrosion rate of lead when exposed to off-gas or degradation products of organic materials used in the model 9975 package.[1] The experiments were completed within the framework of a parametric test matrix with variables of organic configuration, temperature, humidity and the effect of durations of exposure on the corrosion of lead in the 9975 package. The room temperature vulcanizing (RTV) sealant was the most corrosive organic species in the testing, followed by the polyvinyl acetate (PVAc) glue. The Celotex{copyright} material uniquely induced measurable corrosion only in situations with condensed water, and to a much lesser extent than the PVAc glue and RTV. The coupons exhibited faster corrosion at higher temperatures than at room temperatures. There was a particularly pronounced effect of condensed water as the coupons exposed in the cells with condensed water exhibited much higher corrosion rates. In the 9975 package, the PVAc glue was determined to be the most aggressive due to it's proximity in the design. The condition considered most representative of the package conditions is that of the coupon exposed to the Celotex{copyright}/glue organic exposed in the ambient humidity conditions. The corrosion rate of 2 mpy measured in the laboratory …
Date: March 15, 2006
Creator: Subramanian, K
Object Type: Report
System: The UNT Digital Library
Detecting estrogenic activity in water samples withestrogen-sensitive yeast cells using spectrophotometry and fluorescencemicroscopy (open access)

Detecting estrogenic activity in water samples withestrogen-sensitive yeast cells using spectrophotometry and fluorescencemicroscopy

Environmental estrogens are environmental contaminants that can mimic the biological activities of the female hormone estrogen in the endocrine system, i.e. they act as endocrine disrupters. Several substances are reported to have estrogen-like activity or estrogenic activity. These include steroid hormones, synthetic estrogens (xenoestrogens), environmental pollutants and phytoestrogens (plant estrogens). Using the chromogenic substrate ortho-nitrophenyl-{beta}-D-galactopyranoside (ONPG) we show that an estrogen-sensitive yeast strain RMY/ER-ERE, with human estrogen receptor (hER{alpha}) gene and the lacZ gene which encodes the enzyme {beta}-galactosidase, is able to detect estrogenic activity in water samples over a wide range of spiked concentrations of the hormonal estrogen 17{beta}-estradiol (E2). Ortho-nitrophenol (ONP), the yellow product of this assay can be detected using spectrophotometry but requires cell lysis to release the enzyme and allow product formation. We improved this aspect in a fluorogenic assay by using fluorescein di-{beta}-D-galactopyranoside (FDG) as a substrate. The product was visualized using fluorescence microscopy without the need to kill, fix or lyse the cells. We show that in live yeast cells, the uptake of E2 and the subsequent production of {beta}-galactosidase enzyme occur quite rapidly, with maximum enzyme-catalyzed fluorescent product formation evident after about 30 minutes of exposure to E2. The fluorogenic assay was applied …
Date: March 15, 2006
Creator: Wozei, E.; Holman, H-Y.N.; Hermanowicz, S.W. & S., Borglin
Object Type: Article
System: The UNT Digital Library
ENHANCEMENT OF STRUCTURAL FOAM MATERIALS BY INCORPORATION OF GASIFIER SLAG (open access)

ENHANCEMENT OF STRUCTURAL FOAM MATERIALS BY INCORPORATION OF GASIFIER SLAG

As advanced gasification technology is increasingly adopted as an energy source, disposal of the resulting slag will become a problem. We have shown that gasifier slag can be incorporated into foamed glass, which is currently being manufactured as an abrasive and as an insulating material. The slag we add to foamed glass does not simply act as filler, but improves the mechanical properties of the product. Incorporation of gasifier slag can make foamed glass stronger and more abrasion resistant.
Date: March 15, 2006
Creator: Norton, Olin Perry; Palmer, Ronald A. & Ramsey, W. Gene
Object Type: Report
System: The UNT Digital Library
EVALUATION OF VADOSE ZONE TREATMENT TECHNOLOGIES TO IMMOBILIZE TECHNETIUM-99 (open access)

EVALUATION OF VADOSE ZONE TREATMENT TECHNOLOGIES TO IMMOBILIZE TECHNETIUM-99

The Hanford Site End State Vision document (DOE/RL-2003-59) states: ''There should be an aggressive plan to develop technology for remediation of the contamination that could get to the groundwater (particularly the technetium [{sup 99}Tc])''. In addition, there is strong support from the public and regulatory agencies for the above statement, with emphasis on investigation of treatment alternatives. In July 2004, PNNL completed a preliminary evaluation of remediation technologies with respect to their effectiveness and implementability for immobilization of {sup 99}Tc beneath the BC Cribs in the 200 West Area (Truex, 2004). As a result of this evaluation, PNNL recommended treatability testing of in situ soil desiccation, because it has the least uncertainty of those technologies evaluated in July 2004 (Treatability Test Outline, September 30, 2004). In 2005, DOE-RL and Fluor Hanford convened an independent technical panel to review alternative remediation technologies, including desiccation, at a three-day workshop in Richland, Washington. The panel was composed of experts in vadose-zone transport, infiltration control, hydrology, geochemistry, environmental engineering, and geology. Their backgrounds include employment in academia, government laboratories, industry, and consulting. Their review, presented in this document, is based upon written reports from Hanford, oral presentations from Hanford staff, and each panel members' …
Date: March 15, 2006
Creator: PETERSEN, S.W.
Object Type: Report
System: The UNT Digital Library
Final Technical Report DE-FG02-99ER14933 Inversion of multicomponent seismic data and rock physics interpretation (open access)

Final Technical Report DE-FG02-99ER14933 Inversion of multicomponent seismic data and rock physics interpretation

An important accomplishment was to understand the seismic velocity anisotropy resulting from the combined roles of depositional stratification and stress in unconsolidated sands. The report presents an experimental study of velocity anisotropy in unconsolidated sands at measured compressive stresses up to 40 bars, which correspond to the first hundred meters of the subsurface. Two types of velocity anisotropy are considered, that due to intrinsic textural anisotropy, and that due to stress anisotropy. We found that sand samples display a bi-linear dependence of velocity anisotropy with stress anisotropy. There exists a transition stress beyond which the stress-induced anisotropy outweighs the intrinsic anisotropy for three different sands.
Date: March 15, 2006
Creator: Mavko, G.
Object Type: Report
System: The UNT Digital Library
Formulations for the "Characterization of unique compounds in explosives" project (open access)

Formulations for the "Characterization of unique compounds in explosives" project

None
Date: March 15, 2006
Creator: Alcaraz, A. & Dougan, A.
Object Type: Report
System: The UNT Digital Library
Health, Safety, and Environmental Screening and Ranking Frameworkfor Geologic CO2 Storage Site Selection (open access)

Health, Safety, and Environmental Screening and Ranking Frameworkfor Geologic CO2 Storage Site Selection

This report describes a screening and ranking framework(SRF) developed to evaluate potential geologic carbon dioxide (CO2)storage sites on the basis of health, safety, and environmental (HSE)risk arising from possible CO2 leakage. The approach is based on theassumption that HSE risk due to CO2 leakage is dependent on three basiccharacteristics of a geologic CO2 storage site: (1) the potential forprimary containment by the target formation, (2) the potential forsecondary containment if the primary formation leaks, and (3) thepotential for attenuation and dispersion of leaking CO2 if the primaryformation leaks and secondary containment fails. The framework isimplemented in a spreadsheet in which users enter numerical scoresrepresenting expert opinions or general information available frompublished materials along with estimates of uncertainty to evaluate thethree basic characteristics in order to screen and rank candidate sites.Application of the framework to the Rio Vista Gas Field, Ventura OilField, and Mammoth Mountain demonstrates the approach. Refinements andextensions are possible through the use of more detailed data or modelresults in place of property proxies. Revisions and extensions to improvethe approach are anticipated in the near future as it is used and testedby colleagues and collaborators.
Date: March 15, 2006
Creator: Oldenburg, Curtis M.
Object Type: Article
System: The UNT Digital Library
Heat Deposition in Positron Sources for ILC (open access)

Heat Deposition in Positron Sources for ILC

In the International Linear Collider (ILC) positron source, multi-GeV electrons or multi-MeV photons impinge on a metal target to produce the needed positrons in the resulting electromagnetic showers. The incoming beam power is hundreds of kilowatts. Various computer programs -- such as FLUKA or MARS -- can calculate how the incoming beam showers in the target and can track the particle showers through the positron source system. Most of the incoming energy ends up as heat in the various positron source elements. This paper presents results from such calculations and their impact on the design of a positron source for the ILC.
Date: March 15, 2006
Creator: Bharadwaj, V.; Pitthan, R.; Sheppard, J.; Vincke, H. & Wang, J. W.
Object Type: Article
System: The UNT Digital Library
An Intergrated Hydrogen Production-CO2 Capture Process from Fossil Fuel (open access)

An Intergrated Hydrogen Production-CO2 Capture Process from Fossil Fuel

The major project objective is to determine the feasibility of using the char from coal and/or biomass pyrolysis, ammonia and CO2 emissions at smokestacks to produce clean hydrogen and a sequestered carbon fertilizer. During this work period, the project plan, design and test schedules were made on the basis of discussion with partner in experimental issues. Installation of pilot scale units was finished and major units tests were fully performed. Modification of the pyrolyzer, reformer and gas absorption tank have been done. Integration testing is performing recently. Lab scale tests have been performed. Field tests of char/fertilizer have been conducted.
Date: March 15, 2006
Creator: Wang, Z. & Bota, K. B.
Object Type: Report
System: The UNT Digital Library
Main Coast Winds - Final Scientific Report (open access)

Main Coast Winds - Final Scientific Report

The Maine Coast Wind Project was developed to investigate the cost-effectiveness of small, distributed wind systems on coastal sites in Maine. The restructuring of Maine's electric grid to support net metering allowed for the installation of small wind installations across the state (up to 100kW). The study performed adds insight to the difficulties of developing cost-effective distributed systems in coastal environments. The technical hurdles encountered with the chosen wind turbine, combined with the lower than expected wind speeds, did not provide a cost-effective return to make a distributed wind program economically feasible. While the turbine was accepted within the community, the low availability has been a negative.
Date: March 15, 2006
Creator: Huckaby, Jason & Lee, Harley
Object Type: Report
System: The UNT Digital Library
Material Interface Reconstruction for Monte Carlo Particle Tracking (open access)

Material Interface Reconstruction for Monte Carlo Particle Tracking

In this project we implement material interface reconstruction into a large, massively parallel Monte Carlo particle transport code. Here we examine the benefit of resolving a material interface for criticality calculations. Input to the code is a mesh with material and density defined on the mesh. For mesh zones that contain more than one material (mixed zones), the old approximation made in the code is to homogenize the material properties of all the materials in the zone. The neutron mean free path is a function of the material density that the neutron is traveling through, so for mixed zones, we use the average density of the zone, rather than reconstructing a material interface, determining which material within the zone the particle is in and using the correct density based on the position of the particle within the zone. In order to get a better answer, here we implement material interface reconstruction and rather than homogenizing the materials in a mixed zone, we have a material interface divide the zone so we can tell which material the particle is in, based on the particle's position and the location of the material interface.
Date: March 15, 2006
Creator: O'Brien, M J
Object Type: Report
System: The UNT Digital Library
Pasture Management Strategies for Sequestering Soil Carbon - Final Report (open access)

Pasture Management Strategies for Sequestering Soil Carbon - Final Report

Pasturelands account for 51 of the 212 Mha of privately held grazing land in the USA. Tall fescue is the most important cool-season perennial forage for many beef cattle producers in the humid region of the USA. A fungal endophyte, Neotyphodium coenophialum, infects the majority of tall fescue stands with a mutualistic association. Ergot alkaloids produced by the endophyte have negative impacts on cattle performance. However, there are indications that endophyte infection of tall fescue is a necessary component of productive and persistent pasture ecology. The objectives of this research were to characterize and quantify changes in soil organic carbon and associated soil properties under tall fescue pastures with and without endophyte infection of grass. Pastures with high endophyte infection had greater concentration of soil organic carbon, but lower concentration of biologically active soil carbon than pastures with low endophyte infection. A controlled experiment suggested that endophyte-infected leaf tissue may directly inhibit the activity of soil microorganisms. Carbon forms of soil organic matter were negatively affected and nitrogen forms were positively affected by endophyte addition to soil. The chemical compounds in endophyte-infected tall fescue (ergot alkaloids) that are responsible for animal health disorders were found in soil, suggesting that these …
Date: March 15, 2006
Creator: Franzluebbers, Alan J.
Object Type: Report
System: The UNT Digital Library
Post-Irradiation Properties of Candidate Materials for High-Power Targets (open access)

Post-Irradiation Properties of Candidate Materials for High-Power Targets

The desire of the high-energy-physics community for more intense secondary particle beams motivates the development of multi-megawatt, pulsed proton sources. The targets needed to produce these secondary particle beams must be sufficiently robust to withstand the intense pressure waves arising from the high peak-energy deposition which an intense pulsed beam will deliver. In addition, the materials used for the targets must continue to perform in a severe radiation environment. The effect of the beam induced pressure waves can be mitigated by use of target materials with high-yield strength and/or low coefficient of thermal expansion (CTE). We report here first results of an expanded study of the effects of irradiation on several additional candidate materials with high strength (AlBeMet, beryllium, Ti-V6-Al4) or low CTE (a carbon-carbon composite, a new Toyota ''gum'' metal alloy, Super-Invar).
Date: March 15, 2006
Creator: Kirk, H. G.; Ludewig, H.; Mausner, L. F.; Simos, N.; Thieberger, P.; Hayato, Y. et al.
Object Type: Article
System: The UNT Digital Library
Proposal for a High-Brightness Pulsed Electron Source (open access)

Proposal for a High-Brightness Pulsed Electron Source

We propose a novel scheme for a high-brightness pulsedelectron source, which has the potential for many useful applications inelectron microscopy, inverse photo-emission, low energy electronscattering experiments, and electron holography. A description of theproposed scheme is presented.
Date: March 15, 2006
Creator: Zolotorev, Max; Commins, Eugene D.; Heifets, Sam & Sannibale,Fernando
Object Type: Article
System: The UNT Digital Library
Revealing the Jet Structure of Grb 030329 With High Resolution Multicolor Photometry (open access)

Revealing the Jet Structure of Grb 030329 With High Resolution Multicolor Photometry

We present multicolor optical observations of the nearby (z = 0.1685) GRB030329 obtained with the same instrumentation over a time period of 6 hours for a total of an unprecedented 475 quasi-simultaneous B V R observations. The achromatic steepening in the optical, which occurs at t {approx} 0.7 days, provides evidence for a dynamic transition of the source, and can be most readily explained by models in which the GRB ejecta are collimated into a jet. Since the current state-of-the-art modeling of GRB jets is still flawed with uncertainties, we use these data to critically assess some classes of models that have been proposed in the literature. The data, especially the smooth decline rate seen in the optical afterglow, are consistent with a model in which GRB030329 was a homogeneous, sharp-edged jet, viewed near its edge interacting with a uniform external medium, or viewed near its symmetry axis with a stratified wind-like external environment. The lack of short timescale fluctuations in the optical afterglow flux down to the 0.5 per cent level puts stringent constraints on possible small scale angular inhomogeneities within the jet or fluctuations in the external density.
Date: March 15, 2006
Creator: Gorosabel, Javier; Castro-Tirado, A. J.; Ramirez-Ruiz, E.; Granot, J.; Caon, N.; Cairos, L. M. et al.
Object Type: Report
System: The UNT Digital Library
Smart Energy Management and Control for Fuel Cell Based Micro-Grid Connected Neighborhoods (open access)

Smart Energy Management and Control for Fuel Cell Based Micro-Grid Connected Neighborhoods

Fuel cell power generation promises to be an efficient, pollution-free, reliable power source in both large scale and small scale, remote applications. DOE formed the Solid State Energy Conversion Alliance with the intention of breaking one of the last barriers remaining for cost effective fuel cell power generation. The Alliance’s goal is to produce a core solid-state fuel cell module at a cost of no more than $400 per kilowatt and ready for commercial application by 2010. With their inherently high, 60-70% conversion efficiencies, significantly reduced carbon dioxide emissions, and negligible emissions of other pollutants, fuel cells will be the obvious choice for a broad variety of commercial and residential applications when their cost effectiveness is improved. In a research program funded by the Department of Energy, the research team has been investigating smart fuel cell-operated residential micro-grid communities. This research has focused on using smart control systems in conjunction with fuel cell power plants, with the goal to reduce energy consumption, reduce demand peaks and still meet the energy requirements of any household in a micro-grid community environment. In Phases I and II, a SEMaC was developed and extended to a micro-grid community. In addition, an optimal configuration was …
Date: March 15, 2006
Creator: Alam, Dr. Mohammad S.
Object Type: Report
System: The UNT Digital Library
Structural proteomics of minimal organisms: conservation ofprotein fold usage and evolutionary implications (open access)

Structural proteomics of minimal organisms: conservation ofprotein fold usage and evolutionary implications

Background: Determining the complete repertoire of proteinstructures for all soluble, globular proteins in a single organism hasbeen one of the major goals of several structural genomics projects inrecent years. Results: We report that this goal has nearly been reachedfor several "minimal organisms"--parasites or symbionts with reducedgenomes--for which over 95 percent of the soluble, globular proteins maynow be assigned folds, overall 3-D backbone structures. We analyze thestructures of these proteins as they relate to cellular functions, andcompare conservation off old usage between functional categories. We alsocompare patterns in the conservation off olds among minimal organisms andthose observed between minimal organisms and other bacteria. Conclusion:We find that proteins performing essential cellular functions closelyrelated to transcription and translation exhibit a higher degree ofconservation in fold usage than proteins in other functional categories.Folds related to transcription and translation functional categories werealso over represented in minimal organisms compared to otherbacteria.
Date: March 15, 2006
Creator: Chandonia, John-Marc & Kim, Sung-Hou
Object Type: Article
System: The UNT Digital Library
Studies of Room Temperature Accelerator Structures for the ILC Positron Source (open access)

Studies of Room Temperature Accelerator Structures for the ILC Positron Source

There are many challenges in the design of the normal-conducting portion of the ILC positron injector system such as achieving adequate cooling with the high RF and particle loss heating, and sustaining high accelerator gradients during millisecond-long pulses in a strong magnetic field. The proposed design for the positron injector contains both standing-wave and traveling-wave L-band accelerator structures for high RF efficiency, low cost and ease of fabrication. This paper presents results from several studies including particle energy deposition for both undulator based and conventional positron sources, cooling system design, accelerator structure optimization, RF pulse heating, cavity frequency stabilization, and RF feed system design.
Date: March 15, 2006
Creator: Wang, J. W.; Adolphsen, C.; Bharadwaj, V.; Bowden, G. B.; Dolgashev, V. A.; Jones, R. M. et al.
Object Type: Article
System: The UNT Digital Library
Taming the Runaway Problem of Inflationary Landscapes (open access)

Taming the Runaway Problem of Inflationary Landscapes

A wide variety of vacua, and their cosmological realization, may provide an explanation for the apparently anthropic choices of some parameters of particle physics and cosmology. If the probability on various parameters is weighted by volume, a flat potential for slow-roll inflation is also naturally understood, since the flatter the potential the larger the volume of the sub-universe. However, such inflationary landscapes have a serious problem, predicting an environment that makes it exponentially hard for observers to exist and giving an exponentially small probability for a moderate universe like ours. A general solution to this problem is proposed, and is illustrated in the context of inflaton decay and leptogenesis, leading to an upper bound on the reheating temperature in our sub-universe. In a particular scenario of chaotic inflation and non-thermal leptogenesis, predictions can be made for the size of CP violating phases, the rate of neutrinoless double beta decay and, in the case of theories with gauge-mediated weak scale supersymmetry, for the fundamental scale of supersymmetry breaking.
Date: March 15, 2006
Creator: Hall, Lawrence J.; Watari, Taizan & Yanagida, T. T.
Object Type: Article
System: The UNT Digital Library