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2-D Modeling of Energy-z Beam Dynamics Using the LiTrack Matlab Program (open access)

2-D Modeling of Energy-z Beam Dynamics Using the LiTrack Matlab Program

Short bunches and the bunch length distribution have important consequences for both the LCLS project at SLAC and the proposed ILC project. For both these projects, it is important to simulate what bunch length distributions are expected and then to perform actual measurements. The goal of the research is to determine the sensitivity of the bunch length distribution to accelerator phase and voltage. This then indicates the level of control and stability that is needed. In this project I simulated beamlines to find the rms bunch length in three different beam lines at SLAC, which are the test beam to End Station A (ILC-ESA) for the ILC studies, Linac Coherent Light Source (LCLS) and LCLS-ESA. To simulate the beamlines, I used the LiTrack program, which does a 2-dimensional tracking of an electron bunch's longitudinal (z) and the energy spread beam (E) parameters. In order to reduce the time of processing the information, I developed a small program to loop over adjustable machine parameters. LiTrack is a Matlab script and Matlab is also used for plotting and saving and loading files. The results show that the LCLS in Linac-A is the most sensitive when looking at the ratio of change in …
Date: December 15, 2005
Creator: Cauley, S .K. & Woods, M.
Object Type: Report
System: The UNT Digital Library
120 MW, 800 MHz Magnicon for a Future Muon Collider (open access)

120 MW, 800 MHz Magnicon for a Future Muon Collider

Development of a pulsed magnicon at 800 MHz was carried out for the muon collider application, based on experience with similar amplifiers in the frequency range between 915 MHz and 34.3 GHz. Numerical simulations using proven computer codes were employed for the conceptual design, while established design technologies were incorporated into the engineering design. A cohesive design for the 800 MHz magnicon amplifier was carried out, including design of a 200 MW diode electron gun, design of the magnet system, optimization of beam dynamics including space charge effects in the transient and steady-state regimes, design of the drive, gain, and output cavities including an rf choke in the beam exit aperture, analysis of parasitic oscillations and design means to eliminate them, and design of the beam collector capable of 20 kW average power operation.
Date: December 15, 2005
Creator: Hirshfield, Jay L.
Object Type: Report
System: The UNT Digital Library
The Albany News (Albany, Tex.), Vol. 130, No. 29, Ed. 1 Thursday, December 15, 2005 (open access)

The Albany News (Albany, Tex.), Vol. 130, No. 29, Ed. 1 Thursday, December 15, 2005

Weekly newspaper from Albany, Texas that includes local, county, and state news along with extensive advertising.
Date: December 15, 2005
Creator: Lucas, Melinda L.
Object Type: Newspaper
System: The Portal to Texas History
Altus Times (Altus, Okla.), Vol. 107, No. 216, Ed. 1 Thursday, December 15, 2005 (open access)

Altus Times (Altus, Okla.), Vol. 107, No. 216, Ed. 1 Thursday, December 15, 2005

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: December 15, 2005
Creator: Bush, Michael
Object Type: Newspaper
System: The Gateway to Oklahoma History
Analysis of B -> omega lv Decays with BaBar (SULI) (open access)

Analysis of B -> omega lv Decays with BaBar (SULI)

As part of the BaBar project at SLAC to study the properties of B mesons, we have carried out a study of the exclusive charmless semileptonic decay mode B {yields} wlv, which can be used to determine the Cabbibo-Kobayashi-Maskawa matrix element V{sub ub}. Using simulated event samples, this study focuses on determining criteria on variables for selection of B {yields} wlv signal and suppression of background from other types of B{bar B} events and continuum processes. In addition, we determine optimal cuts on variables to ensure a good neutrino reconstruction. With these selection cuts, we were able to achieve a signal-to-background ratio of 0.68 and a signal efficiency of the order of 1%. Applying these cuts to a sample of 83 million B{bar B} events recorded by BaBar in e{sup +}e{sup -} collisions at the {Upsilon}(4S) resonance, we obtain a yield of 115 {+-} 19 B {yields} wlv decays.
Date: December 15, 2005
Creator: Chu, Yi-Wen; /MIT; Littlejohn, B.; /Unlisted; Dingfelder, J. & /SLAC
Object Type: Report
System: The UNT Digital Library
Analysis of Old Copper Synchrotron Light Absorbers from the Stanford Positron Electron Accelerating Ring (open access)

Analysis of Old Copper Synchrotron Light Absorbers from the Stanford Positron Electron Accelerating Ring

Synchrotron light absorbers intercept synchrotron radiation to protect chamber walls from excessive heat. When subjected to the high temperature of the beam, these absorbers undergo thermal stress. If the stress is too great or fatigues the material, the absorbers may fail. These absorbers are designed to last the lifetime of the machine. Any premature cracking could result in a leak and, consequently, loss of the ultra high vacuum environment. Using secondary and backscattered electron techniques, several sections of a used copper absorber were analyzed for material damage. Chemical analyses were performed on these samples as well. Comparing the unexposed sections to the sections exposed to the electron beam, few cracks were seen in the copper. However, the exposed samples showed heavy surface damage, in addition to crevices that could eventually result in material failure. Significant corrosion was also evident along the water cooling passage of the samples. These findings suggest that further investigation and periodic inspection of absorbers in SPEAR3 are necessary to control corrosion of the copper.
Date: December 15, 2005
Creator: Marshall, S. R.; Coll., /F.W. Olin Eng. & Scott, B.
Object Type: Report
System: The UNT Digital Library
Archer County Advocate (Holliday, Tex.), Vol. 3, No. 36, Ed. 1 Thursday, December 15, 2005 (open access)

Archer County Advocate (Holliday, Tex.), Vol. 3, No. 36, Ed. 1 Thursday, December 15, 2005

Weekly newspaper from Holliday, Texas that includes local, state, and national news along with advertising.
Date: December 15, 2005
Creator: Cooper, James H.
Object Type: Newspaper
System: The Portal to Texas History
Archer County News (Archer City, Tex.), No. 50, Ed. 1 Thursday, December 15, 2005 (open access)

Archer County News (Archer City, Tex.), No. 50, Ed. 1 Thursday, December 15, 2005

Weekly newspaper from Archer City, Texas that includes local, state, and national news along with advertising.
Date: December 15, 2005
Creator: Lewis, Shelley
Object Type: Newspaper
System: The Portal to Texas History
An Automated Method for Characterizing the Relaxedness of Galaxy Clusters (open access)

An Automated Method for Characterizing the Relaxedness of Galaxy Clusters

Relaxed galaxy clusters are useful tools for probing cosmological parameters like the gas mass fraction of the universe. Selecting relaxed clusters for this purpose can be a time-consuming and subjective task, so we present methods to automate parts of the process. We fit elliptical isophotes to a diverse sample of Chandra cluster data and summarize other methods for quantifying relaxedness which will be included in future work. Analysis of the results of tests from isophote fitting, combined with numerical simulations of cluster structures and comparison to previous classifications will allow us to formulate criteria for selection of relaxed clusters. We find that they tend to have core radii less than approximately 60 kpc from King model fits, shifts in isophote centroids of less than 25 kpc over a range in semi-major axes of several hundred kpc, and significantly greater surface brightness profile gradients within 30 kpc of their cores than unrelaxed clusters. These criteria will help with future cosmological work as larger amounts of cluster data are taken and need objective classification.
Date: December 15, 2005
Creator: George, Matt & /SLAC, /Harvard Coll. Observ.
Object Type: Report
System: The UNT Digital Library
The BaBar Gas Bubbler Upgrade and Evaluation (open access)

The BaBar Gas Bubbler Upgrade and Evaluation

The Instrumented Flux Return region (muon and K{sub L} detection barrel) of the BaBar detector at SLAC requires careful monitoring of the gas flow through the detector array. This is currently done by a system of digital gas bubblers which monitor the flow rate by using photogate technology to detect the presence of bubbles formed by gas flowing through an internal oil chamber. Recently, however, a design flaw was discovered in these bubblers. Because the bubblers are connected directly to the detector array with no filter, during rises in atmospheric pressure or a drop in the gas flow rate (e.g. when the gas system is shut off for maintenance), the oil in this chamber could be forced backwards into the detector tubes. To compensate for this problem, we upgraded the existing gas bubbler systems by installing metal traps into the old gas lines to capture the oil. This installation was followed by an evaluation of the retro-fitted bubblers during which we determined a relationship between the bubble counting rate and the actual gas flow rate, but encountered recurring problems with baseline fluctuations and unstable bubble counting rates. Future work will involve the study of how these instabilities develop, and whether …
Date: December 15, 2005
Creator: Gan, Yu; U., /Princeton & Young, C.
Object Type: Report
System: The UNT Digital Library
Background Characterization for Thermal Ion Release Experiments with 224Ra (open access)

Background Characterization for Thermal Ion Release Experiments with 224Ra

The Enriched Xenon Observatory for neutrinoless double beta decay uses {sup 136}Ba identification as a means for verifying the decay's occurrence in {sup 136}Xe. A current challenge is the release of Ba ions from the Ba extraction probe, and one possible solution is to heat the probe to high temperatures to release the ions. The investigation of this method requires a characterization of the alpha decay background in our test apparatus, which uses a {sup 228}Th source that produces {sup 224}Ra daughters, the ionization energies of which are similar to those of Ba. For this purpose, we ran a background count with our apparatus maintained at a vacuum, and then three counts with the apparatus filled with Xe gas. We were able to match up our alpha spectrum in vacuum with the known decay scheme of {sup 228}Th, while the spectrum in xenon gas had too many unresolved ambiguities for an accurate characterization. We also found that the alpha decays occurred at a near-zero rate both in vacuum and in xenon gas, which indicates that the rate was determined by {sup 228}Th decays. With these background measurements, we can in the future make a more accurate measurement of the temperature …
Date: December 15, 2005
Creator: Kwong, H.; /Stanford U., Phys. Dept. & Rowson, P.
Object Type: Report
System: The UNT Digital Library
Balloon-Borne Gamma-Ray Polarimeter (PoGO) to Study Black Holes, Pulsars, and AGN Jets: Design and Calibration(SULI) (open access)

Balloon-Borne Gamma-Ray Polarimeter (PoGO) to Study Black Holes, Pulsars, and AGN Jets: Design and Calibration(SULI)

Polarization measurements at X-ray and gamma-ray energies can provide crucial information on the emission region around massive compact objects such as black holes and neutron stars. The Polarized Gamma-ray Observer (PoGO) is a new balloon-borne instrument designed to measure polarization from such astrophysical objects in the 30-100 keV range, under development by an international collaboration with members from United States, Japan, Sweden and France. The PoGO instrument has been designed by the collaboration and several versions of prototype models have been built at SLAC. The purpose of this experiment is to test the latest prototype model with a radioactive gamma-ray source. For this, we have to polarize gamma-rays in a laboratory environment. Unpolarized gamma-rays from Am241 (59.5 keV) were Compton scattered at around 90 degrees for this purpose. Computer simulation of the scattering process in the setup predicts a 86% polarization. The polarized beam was then used to irradiate the prototype PoGO detector. The data taken in this experiment showed a clear polarization signal, with a measured azimuthal modulation factor of 0.35 {+-} 0.02. The measured modulation is in very close agreement with the value expected from a previous beam test study of a polarized gamma-ray beam at the Argonne …
Date: December 15, 2005
Creator: Apte, Zachary & /SLAC, /Hampshire Coll.
Object Type: Report
System: The UNT Digital Library
The Baytown Sun (Baytown, Tex.), Vol. 85, No. 6, Ed. 1 Thursday, December 15, 2005 (open access)

The Baytown Sun (Baytown, Tex.), Vol. 85, No. 6, Ed. 1 Thursday, December 15, 2005

Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.
Date: December 15, 2005
Creator: Cash, Wanda Garner
Object Type: Newspaper
System: The Portal to Texas History
Biomass as Feedstock for a Bioenergy and Bioproducts Industry: The Technical Feasability of a Billion-Ton Annual Supply (open access)

Biomass as Feedstock for a Bioenergy and Bioproducts Industry: The Technical Feasability of a Billion-Ton Annual Supply

The U.S. Department of Energy (DOE) and the U.S. Department of Agriculture (USDA) are both strongly committed to expanding the role of biomass as an energy source. In particular, they support biomass fuels and products as a way to reduce the need for oil and gas imports; to support the growth of agriculture, forestry, and rural economies; and to foster major new domestic industries--biorefineries--making a variety of fuels, chemicals, and other products. As part of this effort, the Biomass R&D Technical Advisory Committee, a panel established by the Congress to guide the future direction of federally funded biomass R&D, envisioned a 30 percent replacement of the current U.S. petroleum consumption with biofuels by 2030. Biomass--all plant and plant-derived materials including animal manure, not just starch, sugar, oil crops already used for food and energy--has great potential to provide renewable energy for America's future. Biomass recently surpassed hydropower as the largest domestic source of renewable energy and currently provides over 3 percent of the total energy consumption in the United States. In addition to the many benefits common to renewable energy, biomass is particularly attractive because it is the only current renewable source of liquid transportation fuel. This, of course, makes …
Date: December 15, 2005
Creator: Perlack, R.D.
Object Type: Report
System: The UNT Digital Library
BRAC Analysis-Notes and Research (open access)

BRAC Analysis-Notes and Research

Contains notes and research (DFAS)Various States-by Bob Cook of the INTERAGENCY Team.
Date: December 15, 2005
Creator: United States. Defense Base Closure and Realignment Commission.
Object Type: Text
System: The UNT Digital Library
BRAC Analysis-Notes and Research (open access)

BRAC Analysis-Notes and Research

Contains notes and research (Postgraduate Education Realignment Scenarios) by Syd Carroll of the JOINT Cross Service Team.
Date: December 15, 2005
Creator: United States. Defense Base Closure and Realignment Commission.
Object Type: Text
System: The UNT Digital Library
BRAC Analysis-Notes and Research (open access)

BRAC Analysis-Notes and Research

Contains notes and research (General) Ellsworth Air Force Base, South Dakota. By Art Beauchamp of the AIR FORCE Team.
Date: December 15, 2005
Creator: United States. Defense Base Closure and Realignment Commission.
Object Type: Text
System: The UNT Digital Library
BRAC Analysis-Notes and Research (open access)

BRAC Analysis-Notes and Research

Contains notes and research (Base Visit) Dyess Air Force Base, Texas, by Tanya Cruz of the AIR FORCE Team.
Date: December 15, 2005
Creator: United States. Defense Base Closure and Realignment Commission.
Object Type: Text
System: The UNT Digital Library
The Canadian Record (Canadian, Tex.), Vol. 115, No. 50, Ed. 1 Thursday, December 15, 2005 (open access)

The Canadian Record (Canadian, Tex.), Vol. 115, No. 50, Ed. 1 Thursday, December 15, 2005

Weekly newspaper from Canadian, Texas that includes local, state and national news along with some advertising.
Date: December 15, 2005
Creator: Brown, Laurie Ezzell
Object Type: Newspaper
System: The Portal to Texas History
CH-TRU Waste Content Codes (CH-TRUCON) (open access)

CH-TRU Waste Content Codes (CH-TRUCON)

The CH-TRU Waste Content Codes (CH-TRUCON) document describes the inventory of the U.S. Department of Energy (DOE) CH-TRU waste within the transportation parameters specified by the Contact-Handled Transuranic Waste Authorized Methods for Payload Control (CH-TRAMPAC). The CH-TRAMPAC defines the allowable payload for the Transuranic Package Transporter-II (TRUPACT-II) and HalfPACT packagings. This document is a catalog of TRUPACT-II and HalfPACT authorized contents and a description of the methods utilized to demonstrate compliance with the CH-TRAMPAC. A summary of currently approved content codes by site is presented in Table 1. The CH-TRAMPAC describes "shipping categories" that are assigned to each payload container. Multiple shipping categories may be assigned to a single content code. A summary of approved content codes and corresponding shipping categories is provided in Table 2, which consists of Tables 2A, 2B, and 2C. Table 2A provides a summary of approved content codes and corresponding shipping categories for the "General Case," which reflects the assumption of a 60-day shipping period as described in the CH-TRAMPAC and Appendix 3.4 of the CH-TRU Payload Appendices. For shipments to be completed within an approximately 1,000-mile radius, a shorter shipping period of 20 days is applicable as described in the CH-TRAMPAC and Appendix 3.5 …
Date: December 15, 2005
Creator: Westinghouse TRU Solutions LLC
Object Type: Report
System: The UNT Digital Library
Civil Rights Opinions of U.S. Supreme Court Nominee Samuel Alito: A Legal Overview (open access)

Civil Rights Opinions of U.S. Supreme Court Nominee Samuel Alito: A Legal Overview

This report provides a legal overview of the civil rights opinions of U.S. Supreme Court nominee Samuel Alito. Judge Alito has written for the majority, concurred, or dissented in several cases alleging discrimination based on race, ethnicity, gender, religion, and other prohibited grounds.
Date: December 15, 2005
Creator: Dale, Charles V.
Object Type: Report
System: The UNT Digital Library
Comanche Chief (Comanche, Tex.), No. 33, Ed. 1 Thursday, December 15, 2005 (open access)

Comanche Chief (Comanche, Tex.), No. 33, Ed. 1 Thursday, December 15, 2005

Weekly newspaper from Comanche, Texas that includes local, state, and national news along with advertising.
Date: December 15, 2005
Creator: Wilkerson, James C., III
Object Type: Newspaper
System: The Portal to Texas History
The Compact Muon Solenoid Heavy Ion program (open access)

The Compact Muon Solenoid Heavy Ion program

The Pb-Pb center of mass energy at the LHC will exceed that of Au-Au collisions at RHIC (Relativistic Heavy Ion Collider) by nearly a factor of 30, providing exciting opportunities for addressing unique physics issues in a completely new energy domain. The interest of the Heavy Ion (HI) Physics at LHC is discussed in more detail in the LHC-USA white paper and the Compact Muon Solenoid (CMS) Heavy Ion proposal. A few highlights are presented in this document. Heavy ion collisions at LHC energies will explore regions of energy and particle density significantly beyond those reachable at RHIC. The energy density of the thermalized matter created at the LHC is estimated to be 20 times higher than at RHIC, implying an initial temperature, which is greater than at RHIC by more than a factor of two. The higher density of produced partons also allows a faster thermalization. As a consequence, the ratio of the quark-gluon plasma lifetime to the thermalization time increases by a factor of 10 over RHIC. Thus the hot, dense systems created in HI collisions at the LHC spend most of the time in a purely partonic state. The longer lifetime of the quark-gluon plasma state widens …
Date: December 15, 2005
Creator: Yepes, Dr. Pablo
Object Type: Report
System: The UNT Digital Library
Cosmological Consequences of String Axions (open access)

Cosmological Consequences of String Axions

Axion fluctuations generated during inflation lead to isocurvature and non-Gaussian temperature fluctuations in the cosmic microwave background radiation. Following a previous analysis for the model independent string axion we consider the consequences of a measurement of these fluctuations for two additional string axions. We do so independent of any cosmological assumptions except for the axions being massless during inflation. The first axion has been shown to solve the strong CP problem for most compactifications of the heterotic string while the second axion, which does not solve the strong CP problem, obeys a mass formula which is independent of the axion scale. We find that if gravitational waves interpreted as arising from inflation are observed by the PLANCK polarimetry experiment with a Hubble constant during inflation of H{sub inf} {approx}> 10{sup 13} GeV the existence of the first axion is ruled out and the second axion cannot obey the scale independent mass formula. In an appendix we quantitatively justify the often held assumption that temperature corrections to the zero temperature QCD axion mass may be ignored for temperatures T {approx}< {Lambda}{sub QCD}.
Date: December 15, 2005
Creator: Kain, Ben
Object Type: Article
System: The UNT Digital Library