Channeling through Bent Crystals (open access)

Channeling through Bent Crystals

Bent crystals have demonstrated potential for use in beam collimation. A process called channeling is when accelerated particle beams are trapped by the nuclear potentials in the atomic planes within a crystal lattice. If the crystal is bent then the particles can follow the bending angle of the crystal. There are several different effects that are observed when particles travel through a bent crystal including dechanneling, volume capture, volume reflection and channeling. With a crystal placed at the edge of a particle beam, part of the fringe of the beam can be deflected away towards a detector or beam dump, thus helping collimate the beam. There is currently FORTRAN code by Igor Yazynin that has been used to model the passage of particles through a bent crystal. Using this code, the effects mentioned were explored for beam energy that would be seen at the Facility for Advanced Accelerator Experimental Tests (FACET) at a range of crystal orientations with respect to the incoming beam. After propagating 5 meters in vacuum space past the crystal the channeled particles were observed to separate from most of the beam with some noise due to dechanneled particles. Progressively smaller bending radii, with corresponding shorter crystal …
Date: September 7, 2012
Creator: Mack, Stephanie & /SLAC, /Ottawa U.
Object Type: Report
System: The UNT Digital Library
Dark Photon Search at BABAR (open access)

Dark Photon Search at BABAR

Presented is the current progress of a search for the signature of a dark photon or new particle using the BaBar data set. We search for the processes e{sup +}e{sup -} {yields} {gamma}{sub ISR}A{prime},A{prime} {yields} e{sup +}e{sup -} and e{sup +}e{sup -} {yields} {gamma}{sub ISR}{gamma}, {gamma} {yields} A{prime},A{prime} {yields} e{sup +}e{sup -}, where {gamma}{sub ISR} is an initial state radiated photon of energy E{sub {gamma}} >= 1 GeV. Twenty-five sets of Monte Carlo, simulating e{sup +}e{sup -} collisions at an energy of 10.58 GeV, were produced with different values of the A{prime} mass ranging from 100 MeV to 9.5 GeV. The mass resolution is calculated based on Monte Carlo simulations. We implement ROOT's Toolkit for Multivariate Analysis (TMVA), a machine learning tool that allows us to evaluate the signal character of events based on many of discriminating variables. TMVA training is conducted with samples of Monte Carlo as signal and a small portion of Run 6 as background. The multivariate analysis produces additional cuts to separate signal and background. The signal efficiency and sensitivity are calculated. The analysis will move forward to fit the background and scan the residuals for the narrow resonance peak of a new particle.
Date: September 7, 2012
Creator: Greenwood, Ross N & /SLAC, /MIT
Object Type: Report
System: The UNT Digital Library
The Evaluation of the Heat Loading from Steady, Transient, and Off-Normal Conditions in ARIES Power Plants (open access)

The Evaluation of the Heat Loading from Steady, Transient, and Off-Normal Conditions in ARIES Power Plants

The heat loading on plasma facing components (PFCs) provides a critical limitation for design and operation of the first wall, divertor, and other special components. Power plants will have high power entering the scrape-off layer and transporting to the first wall and divertor. Although the design for steady heat loads is understood, the approach for transient and offnormal loading is not. The characterization of heat loads developed for ITER1 can be applied to power plants to better develop the operating space of viable solutions and point to research focus areas.
Date: September 7, 2012
Creator: C.E. Kessel, M.S. Tillack and J. Blanchard
Object Type: Article
System: The UNT Digital Library
Longitudinal Bunch Pattern Measurements through Single Photon Counting at SPEAR3 (open access)

Longitudinal Bunch Pattern Measurements through Single Photon Counting at SPEAR3

The Stanford Synchrotron Radiation Lightsource (SSRL), a division of SLAC National Accelerator Laboratory, is a synchrotron light source that provides x-rays for experimental use. As electrons are bent in the storage ring, they emit electromagnetic radiation. There are 372 different buckets which electrons can be loaded into. Different filling patterns produce different types of x-rays. What is the bunch pattern at a given time? Which filling pattern is better? Are there any flaws to the current injection system? These questions can be answered with this single photon counting experiment.
Date: September 7, 2012
Creator: Wang, Hongyi (Jack) & /UC, San Diego
Object Type: Report
System: The UNT Digital Library
Next Generation Print-based Manufacturing for Photovoltaics and Solid State Lighting (open access)

Next Generation Print-based Manufacturing for Photovoltaics and Solid State Lighting

For the grand challenge of reducing our energy and carbon footprint, the development of renewable energy and energy efficient technologies offer a potential solution. Energy technologies can reduce our dependence on foreign oil as well as the energy consumed by the petroleum industry, the leading consumer of energy by a U.S. industry sector. Nonetheless, the manufacturing processes utilized to manufacture equipment for alternative energy technologies often involve energy-intensive processes. This undermines some of the advantages to moving to 'green' technologies in the first place. Our answer to the Industrial Technology Program's (ITP) Grand Challenge FOA was to develop a transformational low cost manufacturing process for plastic-based photovoltaics that will lower by over 50% both energy consumption and greenhouse emissions and offer a return-of-investment of over 20%. We demonstrated a Luminescent Solar Concentrator fabricated on a plastic acrylic substrate (i.e. no glass) that increases the power output of the PV cell by 2.2x with a 2% power efficiency as well as an LSC with a 7% power efficiency that increased the power output from the PV cells by 35%. S large area 20-inch x 60-inch building-integrated photovoltaic window was fabricated using contract manufacturing with a 4% power efficiency which improved the …
Date: September 7, 2012
Creator: Carter, Sue A.
Object Type: Report
System: The UNT Digital Library
Optical Design of a Broadband Infrared Spectrometer for Bunch Length Measurement at the Linac Coherent Light Source (open access)

Optical Design of a Broadband Infrared Spectrometer for Bunch Length Measurement at the Linac Coherent Light Source

The electron pulses generated by the Linac Coherent Light Source at the SLAC National Accelerator Laboratory occur on the order of tens of femtoseconds and cannot be directly measured by conventional means. The length of the pulses can instead be reconstructed by measuring the spectrum of optical transition radiation emitted by the electrons as they move toward a conducting foil. Because the emitted radiation occurs in the mid-infrared from 0.6 to 30 microns a novel optical layout is required. Using a helium-neon laser with wavelength 633 nm, a series of gold-coated off-axis parabolic mirrors were positioned to direct a beam through a zinc selenide prism and to a focus at a CCD camera for imaging. Constructing this layout revealed a number of novel techniques for reducing the aberrations introduced into the system by the off-axis parabolic mirrors. The beam had a recorded radius of less than a millimeter at its final focus on the CCD imager. This preliminary setup serves as a model for the spectrometer that will ultimately measure the LCLS electron pulse duration.
Date: September 7, 2012
Creator: Williams, Kiel
Object Type: Report
System: The UNT Digital Library
PNNL Campus Master Plan (open access)

PNNL Campus Master Plan

The Plan is used as a guide for PNNL in making facility and infrastructure decisions essential to supporting the PNNL vision: to establish a modern, collaborative, flexible, and sustainable campus while optimizing the efficiency of operations in support of courageous discovery and innovation.
Date: September 7, 2012
Creator: Mosey, Whitney LC
Object Type: Report
System: The UNT Digital Library
Recent Developments in X-ray Imaging Technology (open access)

Recent Developments in X-ray Imaging Technology

None
Date: September 7, 2012
Creator: Lanier, R G
Object Type: Report
System: The UNT Digital Library
Representing Range Compensators with Computational Geometry in TOPAS (open access)

Representing Range Compensators with Computational Geometry in TOPAS

In a proton therapy beamline, the range compensator modulates the beam energy, which subsequently controls the depth at which protons deposit energy. In this paper, we introduce two computational representations of range compensator. One of our compensator representations, which we refer to as a subtraction solid-based range compensator, precisely represents the compensator. Our other representation, the 3D hexagon-based range compensator, closely approximates the compensator geometry. We have implemented both of these compensator models in a proton therapy Monte Carlo simulation called TOPAS (Tool for Particle Simulation). In the future, we will present a detailed study of the accuracy and runtime performance trade-offs between our two range compensator representations.
Date: September 7, 2012
Creator: Iandola, Forrest N. & /Illinois U., Urbana /SLAC
Object Type: Report
System: The UNT Digital Library
RF Systems in a Neutrino Factory (open access)

RF Systems in a Neutrino Factory

Based on existing sources, I compile parameters for the RF systems for a neutrino factory which accelerates to 10 GeV.
Date: September 7, 2012
Creator: Berg, J. S.
Object Type: Report
System: The UNT Digital Library
Space Charge Correction on Emittance Measurement of Low Energy Electron Beams (open access)

Space Charge Correction on Emittance Measurement of Low Energy Electron Beams

The goal of any particle accelerator is to optimize the transport of a charged particle beam along a set path by confining the beam to a small region close to the design trajectory and directing it accurately along the beamline. To do so in the simplest fashion, accelerators use a system of magnets that exert approximately linear electromagnetic forces on the charged beam. These electromagnets bend the beam along the desired path, in the case of bending magnets, and constrain the beam to the desired area through alternating focusing and defocusing effects, in the case of quadrupole magnets. We can model the transport of such a beam through transfer matrices representing the actions of the various beamline elements. However, space charge effects, produced from self electric fields within the beam, defocus the beam and must be accounted for in the calculation of beam emittance. We present below the preliminary results of a MATLAB code built to model the transport of a charged particle beam through an accelerator and measure the emittance under the influence of space charge effects. We demonstrate the method of correctly calculating the emittance of a beam under space charge effects using a least square fit to …
Date: September 7, 2012
Creator: Treado, Colleen J. & /Massachusetts U., Amherst
Object Type: Report
System: The UNT Digital Library
STUDY OF THE STABILITY OF PARTICLE MOTION IN STORAGE RINGS. Final Report (open access)

STUDY OF THE STABILITY OF PARTICLE MOTION IN STORAGE RINGS. Final Report

During this period, our research was concentrated on the study of beam-beam effects in large storage-ring colliders and coherent synchrotron radiation (CSR) effect in light sources. Our group was involved in and made significant contribution to several international accelerator projects such as the US-LHC project for the design of the LHC interaction regions, the luminosity upgrade of Tevatron and HERA, the design of eRHIC, and the U.S. LHC Accelerator Research Program (LARP) for the future LHC luminosity upgrade.
Date: September 7, 2012
Creator: Shi, Jack J.
Object Type: Report
System: The UNT Digital Library
Using Dynamic Quantum Clustering to Analyze Hierarchically Heterogeneous Samples on the Nanoscale (open access)

Using Dynamic Quantum Clustering to Analyze Hierarchically Heterogeneous Samples on the Nanoscale

Dynamic Quantum Clustering (DQC) is an unsupervised, high visual data mining technique. DQC was tested as an analysis method for X-ray Absorption Near Edge Structure (XANES) data from the Transmission X-ray Microscopy (TXM) group. The TXM group images hierarchically heterogeneous materials with nanoscale resolution and large field of view. XANES data consists of energy spectra for each pixel of an image. It was determined that DQC successfully identifies structure in data of this type without prior knowledge of the components in the sample. Clusters and sub-clusters clearly reflected features of the spectra that identified chemical component, chemical environment, and density in the image. DQC can also be used in conjunction with the established data analysis technique, which does require knowledge of components present.
Date: September 7, 2012
Creator: Hume, Allison & /SLAC, /Princeton U.
Object Type: Report
System: The UNT Digital Library
An X-Band Gun Test Area at SLAC (open access)

An X-Band Gun Test Area at SLAC

The X-Band Test Area (XTA) is being assembled in the NLCTA tunnel at SLAC to serve as a test facility for new RF guns. The first gun to be tested will be an upgraded version of the 5.6 cell, 200 MV/m peak field X-band gun designed at SLAC in 2003 for the Compton Scattering experiment run in ASTA. This new version includes some features implemented in 2006 on the LCLS gun such as racetrack couplers, increased mode separation and elliptical irises. These upgrades were developed in collaboration with LLNL since the same gun will be used in an injector for a LLNL Gamma-ray Source. Our beamline includes an X-band acceleration section which takes the electron beam up to 100 MeV and an electron beam measurement station. Other X-Band guns such as the UCLA Hybrid gun will be characterized at our facility.
Date: September 7, 2012
Creator: Limborg-Deprey, C.; Adolphsen, C.; Chu, T. S.; Dunning, M. P.; Jobe, R. K.; Jongewaard, E. N. et al.
Object Type: Article
System: The UNT Digital Library
ADDITIVE TESTING FOR IMPROVED SULFUR RETENTION: PRELIMINARY REPORT (open access)

ADDITIVE TESTING FOR IMPROVED SULFUR RETENTION: PRELIMINARY REPORT

The Savannah River National Laboratory is collaborating with Alfred University to evaluate the potential for additives in borosilicate glass to improve sulfur retention. This preliminary report provides further background on the incorporation of sulfur in glass and outlines the experiments that are being performed by the collaborators. A simulated waste glass composition has been selected for the experimental studies. The first phase of experimental work will evaluate the impacts of BaO, PbO, and V{sub 2}O{sub 5} at concentrations of 1.0, 2.0, and 5.0 wt % on sulfate retention in simulated high level waste borosilicate glass. The second phase of experimental work will evaluate the effects of time at the melt temperature on sulfur retention. The resulting samples will be characterized to determine the amount of sulfur remaining as well as to identify the formation of any crystalline phases. The results will be used to guide the future selection of frits and glass forming chemicals in vitrifying Department of Energy wastes containing high sulfur concentrations.
Date: September 7, 2011
Creator: Amoroso, J. & Fox, K.
Object Type: Report
System: The UNT Digital Library
ePLAS Development for Jet Modeling and Applications (open access)

ePLAS Development for Jet Modeling and Applications

Plasma jets provide an alternate approach to the creation of high energy density laboratory plasmas (HEDLP). For the Plasma Liner Experiment (PLX), typically 30 partially ionized argon jets, produced with mini-rail guns, will be focused into a central volume for subsequent magnetic compression into high density plasma liners that can reach high (0.1 Mbar) peak pressures upon stagnation. The jets are typically 2.5 cm in radius traveling at Mach number 30. Ultimate success will require optimized tuning of the rail configurations, the nozzles injecting the gases, and the careful implementation of pre-ionization. The modeling of plasma jet transport is particularly challenging, due the large space (100 sq cm) and time scales (microseconds) involved. Even traditional implicit methods are insufficient, due to the usual need to track electrons explicitly on the mesh. Wall emission and chemistry must be managed, as must ionization of the jet plasma. Ions in the jets are best followed as particles to account properly for collisions upon jet merger. This Phase I Project developed the code ePLAS to attack and successfully surmount many of these challenges. It invented a new 'super implicit' electromagnetic scheme, using implicit electron moment currents that allowed for modeling of jets over multi-cm …
Date: September 7, 2011
Creator: Mason, Dr. Rodney J.
Object Type: Report
System: The UNT Digital Library
Experimental Plans to Explore Dielectric Wakefield Acceleration in the THZ Regime (open access)

Experimental Plans to Explore Dielectric Wakefield Acceleration in the THZ Regime

Dielectric wakefield accelerators have shown great promise toward high-gradient acceleration. We investigate the performances of a possible experiment under consideration at the FLASH facility in DESY to explore wakefield acceleration with an enhanced transformer ratio. The experiment capitalizes on a unique pulse shaping capability recently demonstrated at this facility. In addition, the facility incorporates a superconducting linear accelerator that could generate bunch trains with closely spaced bunches thereby opening the exploration of potential dynamical effects in dielectric wakefield accelerators.
Date: September 7, 2011
Creator: Lemery, F.; Mihalcea, D.; U., /Northern Illinois; Piot, P.; /Fermilab; Behrens, C. et al.
Object Type: Article
System: The UNT Digital Library
Fireside Corrosion USC Steering (open access)

Fireside Corrosion USC Steering

Oxy-Fuel Fireside Research goals are: (1) Determine the effect of oxy-fuel combustion on fireside corrosion - (a) Flue gas recycle choice, Staged combustion ramifications, (c) JCOAL Collaboration; and (2) Develop methods to use chromia solubility in ash as an 'ash corrosivity' measurement - (a) Synthetic ashes at first, then boiler and burner rig ashes, (b) Applicable to SH/RH conditions.
Date: September 7, 2011
Creator: Holcomb, G. R. & Tylczak, J.
Object Type: Article
System: The UNT Digital Library
Materials Performance in USC Steam (open access)

Materials Performance in USC Steam

Materials Performance in USC Steam: (1) pressure effects on steam oxidation - unique capability coming on-line; (2) hydrogen evolution - hydrogen permeability apparatus to determine where hydrogen goes during steam oxidation; and (3) NETL materials development - steam oxidation resource for NETL developed materials.
Date: September 7, 2011
Creator: Holcomb, G. R.; Tylczak, J.; Meier, G. H. & Yanar, N. M.
Object Type: Article
System: The UNT Digital Library
Serial Input Output (open access)

Serial Input Output

Serial Input/Output (SIO) is designed to be a long term storage format of a sophistication somewhere between simple ASCII files and the techniques provided by inter alia Objectivity and Root. The former tend to be low density, information lossy (floating point numbers lose precision) and inflexible. The latter require abstract descriptions of the data with all that that implies in terms of extra complexity. The basic building blocks of SIO are streams, records and blocks. Streams provide the connections between the program and files. The user can define an arbitrary list of streams as required. A given stream must be opened for either reading or writing. SIO does not support read/write streams. If a stream is closed during the execution of a program, it can be reopened in either read or write mode to the same or a different file. Records represent a coherent grouping of data. Records consist of a collection of blocks (see next paragraph). The user can define a variety of records (headers, events, error logs, etc.) and request that any of them be written to any stream. When SIO reads a file, it first decodes the record name and if that record has been defined and …
Date: September 7, 2011
Creator: Waite, Anthony
Object Type: Report
System: The UNT Digital Library
Tracking the Sun IV: An Historical Summary of the Installed Cost of Photovoltaics in the United States from 1998 to 2010 (open access)

Tracking the Sun IV: An Historical Summary of the Installed Cost of Photovoltaics in the United States from 1998 to 2010

The present report describes installed cost trends for grid-connected PV projects installed from 1998 through 2010 (with some limited and preliminary results presented for projects installed in the first six months of 2011). The analysis is based on project-level cost data from approximately 116,500 residential, non-residential, and utility-sector PV systems in the United States. The inclusion of utility-sector PV is a new element in this year’s report. The combined capacity of all systems in the data sample totals 1,685 MW, equal to 79% of all grid-connected PV capacity installed in the United States through 2010 and representing one of the most comprehensive sources of installed PV cost data for the U.S. Based on this dataset, the report describes historical installed cost trends over time, and by location, market segment, technology type, and component. The report also briefly compares recent PV installed costs in the United States to those in Germany and Japan, and describes trends in customer incentives for PV installations and net installed costs after receipt of such incentives. The analysis presented here focuses on descriptive trends in the underlying data, serving primarily to summarize the data in tabular and graphical form.
Date: September 7, 2011
Creator: Darghouth, Naim & Wiser, Ryan
Object Type: Report
System: The UNT Digital Library
The Value of Energy Performance and Green Attributes in Buildings: A Review of Existing Literature and Recommendations for Future Research (open access)

The Value of Energy Performance and Green Attributes in Buildings: A Review of Existing Literature and Recommendations for Future Research

Labels, certifications, and rating systems for energy efficiency performance and “green” attributes of buildings have been available in the U.S. for over 10 years, and used extensively in the European Union and Australia for longer. Such certifications and ratings can make energy efficiency more visible, and could help spur demand for energy efficiency if these designations are shown to have a positive impact on sales or rental prices. This policy brief discusses the findings and methodologies from recent studies on this topic, and suggests recommendations for future research. Although there have been just a handful of studies within the last 10 years that have investigated these effects, a few key findings emerge: To maximize sales price impact, label or rating information must be disclosed early and visibly in the sales process; The approach to evaluating energy efficiency labels (e.g., ENERGY STAR) and general “green” certifications (e.g., LEED or GreenPoint Rated) may need to be different, depending on the type, vintage and market penetration of the label; Collaborative efforts to promote label adoption and build a large dataset of labeled buildings will be required to produce reliable study results.
Date: September 7, 2011
Creator: Stuart, Elizabeth
Object Type: Report
System: The UNT Digital Library
Water Quality Monitoring Requirements in the CGP (open access)

Water Quality Monitoring Requirements in the CGP

None
Date: September 7, 2011
Creator: Campbell, C G
Object Type: Article
System: The UNT Digital Library
Wulanchabu UCG site data-status report (open access)

Wulanchabu UCG site data-status report

None
Date: September 7, 2011
Creator: Wagoner, J
Object Type: Report
System: The UNT Digital Library