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Reversible Electron Beam Heating for Suppression of Micro bunching Instabilities at Free-Electron Lasers (open access)

Reversible Electron Beam Heating for Suppression of Micro bunching Instabilities at Free-Electron Lasers

The presence of microbunching instabilities due to the compression of high-brightness electron beams at existing and future x-ray free-electron lasers (FELs) results in restrictions on the attainable lasing performance and renders beam imaging with optical transition radiation impossible. The instability can be suppressed by introducing additional energy spread, i.e., heating the electron beam, as demonstrated by the successful operation of the laser heater system at the Linac Coherent Light Source. The increased energy spread is typically tolerable for self-amplified spontaneous emission FELs but limits the effectiveness of advanced FEL schemes such as seeding. In this paper, we present a reversible electron beam heating system based on two transverse deflecting radio-frequency structures (TDSs) upstream and downstream of a magnetic bunch compressor chicane. The additional energy spread is introduced in the first TDS, which suppresses the microbunching instability, and then is eliminated in the second TDS. We show the feasibility of the microbunching gain suppression based on calculations and simulations including the effects of coherent synchrotron radiation. Acceptable electron beam and radio-frequency jitter are identified, and inherent options for diagnostics and on-line monitoring of the electron beam's longitudinal phase space are discussed.
Date: May 30, 2012
Creator: Behrens, Christopher; Huang, Zhirong & Xiang, Dao
Object Type: Article
System: The UNT Digital Library
The Altus Times (Altus, Okla.), Vol. 112, No. 293, Ed. 1 Wednesday, May 30, 2012 (open access)

The Altus Times (Altus, Okla.), Vol. 112, No. 293, Ed. 1 Wednesday, May 30, 2012

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: May 30, 2012
Creator: Bush, Michael
Object Type: Newspaper
System: The Gateway to Oklahoma History
Impact Of Melter Internal Design On Off-Gas Flammability (open access)

Impact Of Melter Internal Design On Off-Gas Flammability

The purpose of this study was to: (1) identify the more dominant design parameters that can serve as the quantitative measure of how prototypic a given melter is, (2) run the existing DWPF models to simulate the data collected using both DWPF and non-DWPF melter configurations, (3) confirm the validity of the selected design parameters by determining if the agreement between the model predictions and data is reasonably good in light of the design and operating conditions employed in each data set, and (4) run Computational Fluid Dynamics (CFD) simulations to gain new insights into how fluid mixing is affected by the configuration of melter internals and to further apply the new insights to explaining, for example, why the agreement is not good.
Date: May 30, 2012
Creator: Choi, A. S. & Lee, S. Y.
Object Type: Report
System: The UNT Digital Library
EU-U.S. Economic Ties: Framework, Scope, and Magnitude (open access)

EU-U.S. Economic Ties: Framework, Scope, and Magnitude

This report provides background information and analysis of the U.S.-EU economic relationship for members of the 112th Congress as they contemplate the costs and benefits of closer U.S. economic ties with the EU. It examines the economic and political framework of the relationship and the scope and magnitude of the ties based on data from various sources. In addition, the report analyzes the implications these factors have for U.S. economic policy toward the EU.
Date: May 30, 2012
Creator: Cooper, William H.
Object Type: Report
System: The UNT Digital Library
Water Quality Issues in the 112th Congress: Oversight and Implementation (open access)

Water Quality Issues in the 112th Congress: Oversight and Implementation

None
Date: May 30, 2012
Creator: Copeland, Claudia
Object Type: Report
System: The UNT Digital Library
Water Quality Issues in the 112th Congress: Oversight and Implementation (open access)

Water Quality Issues in the 112th Congress: Oversight and Implementation

This report discusses water quality legislation. A number of Clean Water Act issues have been the subject of congressional oversight and legislation, including the environmental and economic impacts of Chesapeake Bay restoration efforts, federal promulgation of water quality standards in Florida, regulation of surface coal mining activities in Appalachia, and other CWA regulatory actions. Congressional interest in several of these issues has been reflected in debate over policy provisions of legislation providing FY2012 appropriations for EPA (P.L. 112-74).
Date: May 30, 2012
Creator: Copeland, Claudia
Object Type: Report
System: The UNT Digital Library
DESTRUCTIVE EXAMINATION OF SHIPPING PACKAGE 9975-03431 (open access)

DESTRUCTIVE EXAMINATION OF SHIPPING PACKAGE 9975-03431

Destructive and non-destructive examinations have been performed on specified components of shipping package 9975-03431. For those attributes that were also measured during the field surveillance, no significant changes were observed. All observations and test results met identified criteria, or were collected for information and trending purposes. Except for modest corrosion of the lead shield (which is typical of these packages following several years service), no evidence of a degraded condition was found in this package. The Savannah River Site (SRS) stores packages containing plutonium (Pu) materials in the KArea Complex (KAC). The Pu materials are packaged per the DOE 3013 Standard and stored within Model 9975 shipping packages in KAC. The KAC facility DSA (Document Safety Analysis) credits the Model 9975 package to perform several safety functions, including criticality prevention, impact resistance, containment, and fire resistance to ensure the plutonium materials remain in a safe configuration during normal and accident conditions. The Model 9975 package is expected to perform its safety function for at least 12 years from initial packaging. The DSA recognizes the degradation potential for the materials of package construction over time in the KAC storage environment and requires an assessment of materials performance to validate the assumptions …
Date: May 30, 2012
Creator: Daugherty, W.
Object Type: Report
System: The UNT Digital Library
The Express-Star (Chickasha, Okla.), Ed. 1 Wednesday, May 30, 2012 (open access)

The Express-Star (Chickasha, Okla.), Ed. 1 Wednesday, May 30, 2012

Daily newspaper from Chickasha, Oklahoma that includes local, state, and national news along with advertising.
Date: May 30, 2012
Creator: DeSilver, Debi
Object Type: Newspaper
System: The Gateway to Oklahoma History
Brownwood Bulletin (Brownwood, Tex.), Vol. 112, No. 195, Ed. 1 Wednesday, May 30, 2012 (open access)

Brownwood Bulletin (Brownwood, Tex.), Vol. 112, No. 195, Ed. 1 Wednesday, May 30, 2012

Weekly newspaper from Brownwood, Texas that includes local, state and national news along with advertising.
Date: May 30, 2012
Creator: Deason, Gene
Object Type: Newspaper
System: The Portal to Texas History
The Temporary Assistance for Needy Families Block Grant: An Introduction (open access)

The Temporary Assistance for Needy Families Block Grant: An Introduction

None
Date: May 30, 2012
Creator: Falk, Gene
Object Type: Report
System: The UNT Digital Library
Sapulpa Daily Herald (Sapulpa, Okla.), Vol. 97, No. 183, Ed. 1 Wednesday, May 30, 2012 (open access)

Sapulpa Daily Herald (Sapulpa, Okla.), Vol. 97, No. 183, Ed. 1 Wednesday, May 30, 2012

Daily newspaper from Sapulpa, Oklahoma that includes local, state, and national news along with advertising.
Date: May 30, 2012
Creator: Gibbs, Angenene
Object Type: Newspaper
System: The Gateway to Oklahoma History
Cherokeean Herald (Rusk, Tex.), Vol. 163, No. 14, Ed. 1 Wednesday, May 30, 2012 (open access)

Cherokeean Herald (Rusk, Tex.), Vol. 163, No. 14, Ed. 1 Wednesday, May 30, 2012

Weekly newspaper from Rusk, Texas that includes local, state and national news along with extensive advertising.
Date: May 30, 2012
Creator: Gonzalez, Terrie
Object Type: Newspaper
System: The Portal to Texas History

Performance of Hunbol ritual

Houjahen Haokip performs a ritual called Hunbol used for health and prosperity. He is a Thadou speaker from Manipur (currently living in Lambung village), around 80 years old at the time of recording.
Date: May 30, 2012
Creator: Haokip, Pauthang
Object Type: Sound
System: The UNT Digital Library
TWO-CHANNEL DIELECTRIC WAKE FIELD ACCELERATOR (open access)

TWO-CHANNEL DIELECTRIC WAKE FIELD ACCELERATOR

Experimental results are reported for test beam acceleration and deflection in a two-channel, cm-scale, rectangular dielectric-lined wakefield accelerator structure energized by a 14-MeV drive beam. The dominant waveguide mode of the structure is at {approx}30 GHz, and the structure is configured to exhibit a high transformer ratio ({approx}12:1). Accelerated bunches in the narrow secondary channel of the structure are continuously energized via Cherenkov radiation that is emitted by a drive bunch moving in the wider primary channel. Observed energy gains and losses, transverse deflections, and changes in the test bunch charge distribution compare favorably with predictions of theory.
Date: May 30, 2012
Creator: Hirshfield, Jay L.
Object Type: Report
System: The UNT Digital Library
Second Line of Defense, Megaports Initiative, Operational Testing and Evaluation Plan, Port of Lazaro Cardenas, Mexico (open access)

Second Line of Defense, Megaports Initiative, Operational Testing and Evaluation Plan, Port of Lazaro Cardenas, Mexico

The purpose of the Operational Testing and Evaluation (OT&E) phases of the project is to prepare for turnover of the Megaports System supplied by U.S. Department of Energy/National Nuclear Security Administration (DOE/NNSA)—located at the Export Lanes of the Port of Lazaro Cardenas, Mexico—to the Government of Mexico (GOM).
Date: May 30, 2012
Creator: Hughes, Jamie D.
Object Type: Report
System: The UNT Digital Library
Enhanced Generic Phase-field Model of Irradiation Materials: Fission Gas Bubble Growth Kinetics in Polycrystalline UO2 (open access)

Enhanced Generic Phase-field Model of Irradiation Materials: Fission Gas Bubble Growth Kinetics in Polycrystalline UO2

Experiments show that inter-granular and intra-granular gas bubbles have different growth kinetics which results in heterogeneous gas bubble microstructures in irradiated nuclear fuels. A science-based model predicting the heterogeneous microstructure evolution kinetics is desired, which enables one to study the effect of thermodynamic and kinetic properties of the system on gas bubble microstructure evolution kinetics and morphology, improve the understanding of the formation mechanisms of heterogeneous gas bubble microstructure, and provide the microstructure to macroscale approaches to study their impact on thermo-mechanical properties such as thermo-conductivity, gas release, volume swelling, and cracking. In our previous report 'Mesoscale Benchmark Demonstration, Problem 1: Mesoscale Simulations of Intra-granular Fission Gas Bubbles in UO2 under Post-irradiation Thermal Annealing', we developed a phase-field model to simulate the intra-granular gas bubble evolution in a single crystal during post-irradiation thermal annealing. In this work, we enhanced the model by incorporating thermodynamic and kinetic properties at grain boundaries, which can be obtained from atomistic simulations, to simulate fission gas bubble growth kinetics in polycrystalline UO2 fuels. The model takes into account of gas atom and vacancy diffusion, vacancy trapping and emission at defects, gas atom absorption and resolution at gas bubbles, internal pressure in gas bubbles, elastic interaction …
Date: May 30, 2012
Creator: Li, Yulan; Hu, Shenyang Y.; Montgomery, Robert O.; Gao, Fei & Sun, Xin
Object Type: Report
System: The UNT Digital Library
The Oklahoma Daily (Norman, Okla.), Vol. 97, No. 156, Ed. 1 Wednesday, May 30, 2012 (open access)

The Oklahoma Daily (Norman, Okla.), Vol. 97, No. 156, Ed. 1 Wednesday, May 30, 2012

Student newspaper of the University of Oklahoma in Norman, Oklahoma that includes national, local, and campus news along with advertising.
Date: May 30, 2012
Creator: Lusk, Chris
Object Type: Newspaper
System: The Gateway to Oklahoma History
DART schedules community meetings on proposed new transit fares (open access)

DART schedules community meetings on proposed new transit fares

News release about a series of community meetings hosted by DART to acquire public input on DART's proposed fare changes.
Date: May 30, 2012
Creator: Lyons, Morgan & Ball, Mark
Object Type: Text
System: The Portal to Texas History
Yoakum Herald-Times (Yoakum, Tex.), Vol. 120, No. 22, Ed. 1 Wednesday, May 30, 2012 (open access)

Yoakum Herald-Times (Yoakum, Tex.), Vol. 120, No. 22, Ed. 1 Wednesday, May 30, 2012

Weekly newspaper from Yoakum, Texas that includes local, state, and national news along with advertising.
Date: May 30, 2012
Creator: McCracken, Michael S.
Object Type: Newspaper
System: The Portal to Texas History
Oral History Interview with George W. Meyers, May 30, 2012 transcript

Oral History Interview with George W. Meyers, May 30, 2012

The National Museum of the Pacific War presents an oral interview with George W. Meyers. Meyers worked as a welder and on an oil rig prior to joining the Navy just after the attack on Pearl Harbor. Meyers was eventually assigned to a naval construction battalion and recalls assembling massive oil tanks, a hospital and a radar installation in the Solomon Islands. He also shares anecdotes about welding pontoons together at the Admiralty Islands. Meyers was discharged in November, 1945.
Date: May 30, 2012
Creator: Meyers, George W.
Object Type: Sound
System: The Portal to Texas History
Oral History Interview with George W. Meyers, May 30, 2012 (open access)

Oral History Interview with George W. Meyers, May 30, 2012

The National Museum of the Pacific War presents an oral interview with George W. Meyers. Meyers worked as a welder and on an oil rig prior to joining the Navy just after the attack on Pearl Harbor. Meyers was eventually assigned to a naval construction battalion and recalls assembling massive oil tanks, a hospital and a radar installation in the Solomon Islands. He also shares anecdotes about welding pontoons together at the Admiralty Islands. Meyers was discharged in November, 1945.
Date: May 30, 2012
Creator: Meyers, George W.
Object Type: Text
System: The Portal to Texas History
Extension of the Bayesloc Multiple-Event Location Algorithm to Include Differential Travel Time Measurements (open access)

Extension of the Bayesloc Multiple-Event Location Algorithm to Include Differential Travel Time Measurements

None
Date: May 30, 2012
Creator: Myers, S C & Johannesson, G
Object Type: Article
System: The UNT Digital Library
Veterans' Medical Care: FY2013 Appropriations (open access)

Veterans' Medical Care: FY2013 Appropriations

This report focuses on the Veterans Health Administration (VHA). The VHA is primarily a direct service provider of primary care, specialized care, and related medical and social support services to veterans through the nation's largest integrated health care system.
Date: May 30, 2012
Creator: Panangala, Sidath Viranga
Object Type: Report
System: The UNT Digital Library
U.S. Solar Photovoltaic Manufacturing: Industry Trends, Global Competition, Federal Support (open access)

U.S. Solar Photovoltaic Manufacturing: Industry Trends, Global Competition, Federal Support

The most widely used solar technology involves photovoltaic (PV) solar modules, which draw on semiconducting materials to convert sunlight into electricity. By year-end 2011, the total number of grid-connected PV systems nationwide reached almost 215,000. Domestic demand is met both by imports and by about 100 U.S. manufacturing facilities. The competitiveness of solar PV as a source of electric generation in the United States will likely be adversely affected both by the expiration of tax provisions and by the rapid development of shale gas, which has the potential to lower the cost of gas-fired power generation and reduce the cost-competitiveness of solar power, particularly as an energy source for utilities. In light of these developments, the ability to build a significant U.S. production base for PV equipment is in question.
Date: May 30, 2012
Creator: Platzer, Michaela D.
Object Type: Report
System: The UNT Digital Library