Electronic Structure Differences Between H2-, Fe-, Co-, and Cu-Phthalocyanine Highly Oriented Thin Films Observed Using NEXAFS Spectroscopy (open access)

Electronic Structure Differences Between H2-, Fe-, Co-, and Cu-Phthalocyanine Highly Oriented Thin Films Observed Using NEXAFS Spectroscopy

None
Date: October 12, 2012
Creator: Willey, T M; Bagge-Hansen, M; Lee, J I; Call, R; Landt, L; van Buuren, T et al.
Object Type: Article
System: The UNT Digital Library
The Effect of Hydrogen and Fluorine Coadsorption on the Piezoelectric Properties of Graphene (open access)

The Effect of Hydrogen and Fluorine Coadsorption on the Piezoelectric Properties of Graphene

None
Date: November 12, 2012
Creator: Ong, M T; Duerloo, K N & Reed, E J
Object Type: Article
System: The UNT Digital Library
April 2012 Groundwater and Surface Water Sampling at the Salmon, Mississippi, Site (Data Validation Package) (open access)

April 2012 Groundwater and Surface Water Sampling at the Salmon, Mississippi, Site (Data Validation Package)

Sampling and analysis were conducted on April 16-19, 2012, as specified in the Sampling and Analysis Plan for U.S. Department of Energy Office Of Legacy Management Sites (LMS/PLN/S04351, continually updated). Duplicate samples were collected from locations SA1-1-H, HMH-5R, SA3-4-H, SA1-2-H, Pond W of GZ, and SA5-4-4. One trip blank was collected during this sampling event.
Date: October 12, 2012
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Livermore Computer Network Simulation Program (open access)

Livermore Computer Network Simulation Program

None
Date: January 12, 2012
Creator: Barnes, P. D.; Brase, J. M.; Canales, T. W.; Damante, M. M.; Horsley, M. A.; Jefferson, D. R. et al.
Object Type: Article
System: The UNT Digital Library
Ab Initio Calculations Of Light-Ion Reactions (open access)

Ab Initio Calculations Of Light-Ion Reactions

The exact treatment of nuclei starting from the constituent nucleons and the fundamental interactions among them has been a long-standing goal in nuclear physics. In addition to the complex nature of nuclear forces, one faces the quantum-mechanical many-nucleon problem governed by an interplay between bound and continuum states. In recent years, significant progress has been made in ab initio nuclear structure and reaction calculations based on input from QCD employing Hamiltonians constructed within chiral effective field theory. In this contribution, we present one of such promising techniques capable of describing simultaneously both bound and scattering states in light nuclei. By combining the resonating-group method (RGM) with the ab initio no-core shell model (NCSM), we complement a microscopic cluster approach with the use of realistic interactions and a microscopic and consistent description of the clusters. We discuss applications to light nuclei scattering, radiative capture and fusion reactions.
Date: March 12, 2012
Creator: Navratil, P; Quaglioni, S; Roth, R & Horiuchi, W
Object Type: Article
System: The UNT Digital Library
Statistical Evaluation of Small Scale Mixing Demonstration Sampling and Batch Transfer Performance - 12093 (open access)

Statistical Evaluation of Small Scale Mixing Demonstration Sampling and Batch Transfer Performance - 12093

The ability to effectively mix, sample, certify, and deliver consistent batches of High Level Waste (HLW) feed from the Hanford Double Shell Tanks (DST) to the Waste Treatment and Immobilization Plant (WTP) presents a significant mission risk with potential to impact mission length and the quantity of HLW glass produced. DOE's Tank Operations Contractor, Washington River Protection Solutions (WRPS) has previously presented the results of mixing performance in two different sizes of small scale DSTs to support scale up estimates of full scale DST mixing performance. Currently, sufficient sampling of DSTs is one of the largest programmatic risks that could prevent timely delivery of high level waste to the WTP. WRPS has performed small scale mixing and sampling demonstrations to study the ability to sufficiently sample the tanks. The statistical evaluation of the demonstration results which lead to the conclusion that the two scales of small DST are behaving similarly and that full scale performance is predictable will be presented. This work is essential to reduce the risk of requiring a new dedicated feed sampling facility and will guide future optimization work to ensure the waste feed delivery mission will be accomplished successfully. This paper will focus on the analytical …
Date: January 12, 2012
Creator: Greer, D. A. & Thien, M. G.
Object Type: Article
System: The UNT Digital Library
SLUDGE HEEL REMOVAL BY ALUMINUM DISSOLUTION AT SAVANNAH RIVER SITE 12390 (open access)

SLUDGE HEEL REMOVAL BY ALUMINUM DISSOLUTION AT SAVANNAH RIVER SITE 12390

High Level Waste (HLW) at the Savannah River Site (SRS) is currently stored in aging underground storage tanks. This waste is a complex mixture of insoluble solids, referred to as sludge, and soluble salts. Continued long-term storage of these radioactive wastes poses an environmental risk. Operations are underway to remove and disposition the waste, clean the tanks and fill with grout for permanent closure. Heel removal is the intermediate phase of the waste retrieval and tank cleaning process at SRS, which is intended to reduce the volume of waste prior to treatment with oxalic acid. The goal of heel removal is to reduce the residual amount of radioactive sludge wastes to less than 37,900 liters (10,000 gallons) of wet solids. Reducing the quantity of residual waste solids in the tank prior to acid cleaning reduces the amount of acid required and reduces the amount of excess acid that could impact ongoing waste management processes. Mechanical heel removal campaigns in Tank 12 have relied solely on the use of mixing pumps that have not been effective at reducing the volume of remaining solids. The remaining waste in Tank 12 is known to have a high aluminum concentration. Aluminum dissolution by caustic …
Date: January 12, 2012
Creator: Keefer, M.
Object Type: Article
System: The UNT Digital Library
Experimental Characterization of Space Charge in IZIP Detectors (open access)

Experimental Characterization of Space Charge in IZIP Detectors

Interleaved ionization electrode geometries offer the possibility of efficient rejection of near-surface events. The CDMS collaboration has recently implemented this interleaved approach for the charge and phonon readout for our germanium detectors. During a recent engineering run, the detectors were found to lose ionization stability quickly. This paper summarizes studies done in order to determine the underlying cause of the instability, as well as possible running modes that maintain stability without unacceptable loss of livetime. Additionally, results are shown for the new version IZIP mask which attempts to improve the overall stability of the detectors.
Date: June 12, 2012
Creator: Doughty, T; /UC, Berkeley; Pyle, M.; U., /Stanford; Mirabolfathi, N.; Serfass, B. et al.
Object Type: Article
System: The UNT Digital Library
Boosted Objects: A Probe of Beyond the Standard Model Physics (open access)

Boosted Objects: A Probe of Beyond the Standard Model Physics

We present the report of the hadronic working group of the BOOST2010 workshop held at the University of Oxford in June 2010. The first part contains a review of the potential of hadronic decays of highly boosted particles as an aid for discovery at the LHC and a discussion of the status of tools developed to meet the challenge of reconstructing and isolating these topologies. In the second part, we present new results comparing the performance of jet grooming techniques and top tagging algorithms on a common set of benchmark channels. We also study the sensitivity of jet substructure observables to the uncertainties in Monte Carlo predictions.
Date: June 12, 2012
Creator: Abdesselam, A.; U., /Oxford; Kuutmann, E.Bergeaas; /DESY; Bitenc, U.; U., /Freiburg et al.
Object Type: Article
System: The UNT Digital Library
RESULTS OF ANALYSES OF THE NEXT GENERATION SOLVENT FOR PARSONS (open access)

RESULTS OF ANALYSES OF THE NEXT GENERATION SOLVENT FOR PARSONS

Savannah River National Laboratory (SRNL) prepared a nominal 150 gallon batch of Next Generation Solvent (NGS) for Parsons. This material was then analyzed and tested for cesium mass transfer efficiency. The bulk of the results indicate that the solvent is qualified as acceptable for use in the upcoming pilot-scale testing at Parsons Technology Center. This report describes the analysis and testing of a batch of Next Generation Solvent (NGS) prepared in support of pilot-scale testing in the Parsons Technology Center. A total of {approx}150 gallons of NGS solvent was prepared in late November of 2011. Details for the work are contained in a controlled laboratory notebook. Analysis of the Parsons NGS solvent indicates that the material is acceptable for use. SRNL is continuing to improve the analytical method for the guanidine.
Date: March 12, 2012
Creator: Peters, T.; Washington, A. & Fink, S.
Object Type: Report
System: The UNT Digital Library
HANFORD SITE SUSTAINABILITY PROGRAM RICHLAND WASHINGTON - 12464 (open access)

HANFORD SITE SUSTAINABILITY PROGRAM RICHLAND WASHINGTON - 12464

In support of implementation of Executive Order (EO) 13514, Federal Leadership in Environmental, Energy and Economic Performance, the Hanford Site Sustainability Plan was developed to implement strategies and activities required to achieve the prescribed goals in the EO as well as demonstrate measurable progress in environmental stewardship at the Hanford Site. The Hanford Site Sustainability Program was developed to demonstrate progress towards sustainability goals as defined and established in Executive Order (EO) 13514, Federal Leadership in Environmental, Energy and Economic Performance; EO 13423, Strengthening Federal Environmental, Energy and Transportation Management, and several applicable Energy Acts. Multiple initiatives were undertaken in Fiscal Year (FY) 2011 to implement the Program and poise the Hanford Site as a leader in environmental stewardship. In order to implement the Hanford Site Sustainability Program, a Sustainability Plan was developed in conjunction with prime contractors, two U.S. Department of Energy (DOE) Offices, and key stakeholders to serve as the framework for measuring progress towards sustainability goals. Based on the review of these metrics and future plans, several activities were initiated to proactively improve performance or provide alternatives for future consideration contingent on available funding. A review of the key metric associated with energy consumption for the Hanford …
Date: January 12, 2012
Creator: LL, FRITZ
Object Type: Article
System: The UNT Digital Library
Generation of Coherent X-Ray Radiation through Modulation Compression (open access)

Generation of Coherent X-Ray Radiation through Modulation Compression

In this paper, we propose a scheme to generate tunable coherent X-ray radiation for future light source applications. This scheme uses an energy chirped electron beam, a laser modulator, a laser chirper and two bunch compressors to generate a prebunched kilo-Ampere current electron beam from a few tens Ampere electron beam out of a linac. The initial modulation energy wavelength can be compressed by a factor of 1 + h{sub b}R{sub 56}{sup a} in phase space, where h{sub b} is the energy bunch length chirp introduced by the laser chirper, R{sub 56}{sup a} is the momentum compaction factor of the first bunch compressor. As an illustration, we present an example to generate more than 400 MW, 170 attoseconds pulse, 1 nm coherent X-ray radiation using a 60 A electron beam out of the linac and 200 nm laser seed. Both the final wavelength and the radiation pulse length in the proposed scheme are tunable by adjusting the compression factor and the laser parameters.
Date: June 12, 2012
Creator: Qiang, Ji; /LBL, Berkeley & Wu, Juhao
Object Type: Article
System: The UNT Digital Library
Program Development Tools and Infrastructures (open access)

Program Development Tools and Infrastructures

Exascale class machines will exhibit a new level of complexity: they will feature an unprecedented number of cores and threads, will most likely be heterogeneous and deeply hierarchical, and offer a range of new hardware techniques (such as speculative threading, transactional memory, programmable prefetching, and programmable accelerators), which all have to be utilized for an application to realize the full potential of the machine. Additionally, users will be faced with less memory per core, fixed total power budgets, and sharply reduced MTBFs. At the same time, it is expected that the complexity of applications will rise sharply for exascale systems, both to implement new science possible at exascale and to exploit the new hardware features necessary to achieve exascale performance. This is particularly true for many of the NNSA codes, which are large and often highly complex integrated simulation codes that push the limits of everything in the system including language features. To overcome these limitations and to enable users to reach exascale performance, users will expect a new generation of tools that address the bottlenecks of exascale machines, that work seamlessly with the (set of) programming models on the target machines, that scale with the machine, that provide automatic …
Date: March 12, 2012
Creator: Schulz, M
Object Type: Report
System: The UNT Digital Library
A Measurement of the Semileptonic Branching Fraction of the B_s Meson (open access)

A Measurement of the Semileptonic Branching Fraction of the B_s Meson

We report a measurement of the inclusive semileptonic branching fraction of the B{sub s} meson using data collected with the BABAR detector in the center-of-mass energy region above the {gamma}(4S) resonance. We use the inclusive yield of {phi} mesons and the {phi} yield in association with a high-momentum lepton to perform a simultaneous measurement of the semileptonic branching fraction and the production rate of B{sub s} mesons relative to all B mesons as a function of center-of-mass energy. The inclusive semileptonic branching fraction of the B{sub s} meson is determined to be {Beta}(B{sub s} {yields} {ell}{nu}X) = 9.5{sub -2.0}{sup +2.5}(stat){sub -1.9}{sup +1.1}(syst)%, where {ell} indicates the average of e and {mu}.
Date: June 12, 2012
Creator: Lees, J. P.; Poireau, V.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M. et al.
Object Type: Article
System: The UNT Digital Library
Passive Acoustic Detection of Wind Turbine In-Flow Conditions for Active Control and Optimization (open access)

Passive Acoustic Detection of Wind Turbine In-Flow Conditions for Active Control and Optimization

Wind is a significant source of energy; however, the human capability to produce electrical energy still has many hurdles to overcome. One of these is the unpredictability of the winds in the atmospheric boundary layer (ABL). The ABL is highly turbulent in both stable and unstable conditions (based on the vertical temperature profile) and the resulting fluctuations can have a dramatic impact on wind turbine operation. Any method by which these fluctuations could be observed, estimated, or predicted could provide a benefit to the wind energy industry as a whole. Based on the fundamental coupling of velocity fluctuations to pressure fluctuations in the nearly incompressible flow in the ABL, This work hypothesizes that a ground-based array of infrasonic pressure transducers could be employed to estimate the vertical wind profile over a height relevant for wind turbines. To analyze this hypothesis, experiments and field deployments were conducted. Wind tunnel experiments were performed for a thick turbulent boundary layer over a neutral or heated surface. Surface pressure and velocity probe measurements were acquired simultaneously. Two field deployments yielded surface pressure data from a 49 element array. The second deployment at the Reese Technology Center in Lubbock, TX, also included data from a …
Date: March 12, 2012
Creator: Murray, Nathan E.
Object Type: Report
System: The UNT Digital Library
Radioactive Demonstrations of Fluidized Bed Steam Reforming With Acutal Hanford Low Activity Wastes Verifying Fbsr as a Supplementary Treatment (open access)

Radioactive Demonstrations of Fluidized Bed Steam Reforming With Acutal Hanford Low Activity Wastes Verifying Fbsr as a Supplementary Treatment

The U.S. Department of Energy's Office of River Protection is responsible for the retrieval, treatment, immobilization, and disposal of Hanford's tank waste. Currently there are approximately 56 million gallons of highly radioactive mixed wastes awaiting treatment. A key aspect of the River Protection Project cleanup mission is to construct and operate the Waste Treatment and Immobilization Plant (WTP). The WTP will separate the tank waste into high-level waste (HLW) and low-activity waste (LAW) fractions, both of which will subsequently be vitrified. The projected throughput capacity of the WTP LAW Vitrification Facility is insufficient to complete the cleanup mission in the time frame required by the Hanford Federal Facility Agreement and Consent Order, also known as the Tri-Party Agreement (TPA). Therefore, Supplemental Treatment is required both to meet the TPA treatment requirements as well as to more cost effectively complete the tank waste treatment mission. Fluidized Bed Steam Reforming (FBSR) is one of the supplementary treatments being considered. FBSR offers a moderate temperature (700-750 C) continuous method by which LAW and other secondary wastes can be processed irrespective of whether they contain organics, nitrates/nitrites, sulfates/sulfides, chlorides, fluorides, and/or radio-nuclides like I-129 and Tc-99. Radioactive testing of Savannah River LAW (Tank 50) …
Date: January 12, 2012
Creator: Jantzen, Carol M.; Crawford, C. L.; Burket, P. R.; Bannochie, C. J.; Daniel, W. G.; Nash, C. A. et al.
Object Type: Article
System: The UNT Digital Library
Confinement Contains Condensates (open access)

Confinement Contains Condensates

Dynamical chiral symmetry breaking and its connection to the generation of hadron masses has historically been viewed as a vacuum phenomenon. We argue that confinement makes such a position untenable. If quark-hadron duality is a reality in QCD, then condensates, those quantities that have commonly been viewed as constant empirical mass-scales that fill all spacetime, are instead wholly contained within hadrons; i.e., they are a property of hadrons themselves and expressed, e.g., in their Bethe-Salpeter or light-front wave functions. We explain that this paradigm is consistent with empirical evidence, and incidentally expose misconceptions in a recent Comment.
Date: March 12, 2012
Creator: Brodsky, Stanley J.; Roberts, Craig D.; Shrock, Robert & Tandy, Peter C.
Object Type: Article
System: The UNT Digital Library
SALTSTONE 3QCY11 TCLP RESULTS (open access)

SALTSTONE 3QCY11 TCLP RESULTS

A Saltstone waste form was prepared in the Savannah River National Laboratory (SRNL) from a Tank 50H sample and Z-Area premix material for the third quarter of calendar year 2011 (3QCY11). After the prescribed 32 day cure, samples of the saltstone were collected, and the waste form was shown to meet the South Carolina Hazardous Waste Management Regulations (SCHWMR) R.61-79.261.24 and R.61-79.268.48(a) requirements for a nonhazardous waste form with respect to RCRA metals and underlying hazardous constituents. These analyses met all quality assurance specifications of USEPA SW-846. The Saltstone Production Facility (SPF) receives waste from Tank 50H for treatment. In the third quarter of the 2011 calendar year (3QCY11), Tank 50H accepted transfers of approximately 20 kgal from the Effluent Treatment Project (ETP), approximately 236 kgal from the Actinide Removal Process/Modular Caustic Side Solvent Extraction Unit (ARP/MCU) Decontaminated Salt Solution Hold Tank (DSS-HT), and approximately 25 kgal from other sources. The Saltstone Grout Sampling plan provides the South Carolina Department of Health and Environmental Control (SCDHEC) with the chemical and physical characterization strategy for the salt solution which is to be disposed of in the Z-Area Solid Waste Landfill (SWLF). During operation, samples were collected from Tank 50H and grout …
Date: January 12, 2012
Creator: Bannochie, C.
Object Type: Report
System: The UNT Digital Library
Modular, High-Volume Fuel Cell Leak-Test Suite and Process (open access)

Modular, High-Volume Fuel Cell Leak-Test Suite and Process

Fuel cell stacks are typically hand-assembled and tested. As a result the manufacturing process is labor-intensive and time-consuming. The fluid leakage in fuel cell stacks may reduce fuel cell performance, damage fuel cell stack, or even cause fire and become a safety hazard. Leak check is a critical step in the fuel cell stack manufacturing. The fuel cell industry is in need of fuel cell leak-test processes and equipment that is automatic, robust, and high throughput. The equipment should reduce fuel cell manufacturing cost.
Date: March 12, 2012
Creator: Chen, Ru & Kaye, Ian
Object Type: Report
System: The UNT Digital Library
THE EFFECT OF THE PRESENCE OF OZONE ON THE LOWER FLAMMABILITY LIMIT OF HYDROGEN IN VESSELS CONTAINING SAVANNAH RIVER SITE HIGH LEVEL WASTE (open access)

THE EFFECT OF THE PRESENCE OF OZONE ON THE LOWER FLAMMABILITY LIMIT OF HYDROGEN IN VESSELS CONTAINING SAVANNAH RIVER SITE HIGH LEVEL WASTE

The Enhanced Chemical Cleaning (ECC) process uses ozone to effect the oxidation of metal oxalates produced during the dissolution of sludge in the Savannah River Site (SRS) waste tanks. The ozone reacts with the metal oxalates to form metal oxide and hydroxide precipitants, and the CO{sub 2}, O{sub 2}, H{sub 2}O and any unreacted O{sub 3} gases are discharged into the vapor space. In addition to the non-radioactive metals in the waste, however, the SRS radioactive waste also contains a variety of radionuclides, hence, hydrogen gas is also present in the vapor space of the ECC system. Because hydrogen is flammable, the impact of this resultant gas stream on the Lower Flammability Limit (LFL) of hydrogen must be understood for all possible operating scenarios of both normal and off-normal situations, with particular emphasis at the elevated temperatures and pressures of the typical ECC operating conditions. Oxygen is a known accelerant in combustion reactions, but while there are data associated with the behavior of hydrogen/oxygen environments, recent, relevant studies addressing the effect of ozone on the flammability limit of hydrogen proved scarce. Further, discussions with industry experts verified the absence of data in this area and indicated that laboratory testing, specific …
Date: January 12, 2012
Creator: Sherburne, C.
Object Type: Article
System: The UNT Digital Library
Leveraging Available Data to Support Extension of Transportation Packages Service Life (open access)

Leveraging Available Data to Support Extension of Transportation Packages Service Life

Data obtained from testing shipping package materials have been leveraged to support extending the service life of select shipping packages while in nuclear materials transportation. Increasingly, nuclear material inventories are being transferred to an interim storage location where they will reside for extended periods of time. Use of a shipping package to store nuclear materials in an interim storage location has become more attractive for a variety of reasons. Shipping packages are robust and have a qualified pedigree for their performance in normal operation and accident conditions within the approved shipment period and storing nuclear material within a shipping package results in reduced operations for the storage facility. However, the shipping package materials of construction must maintain a level of integrity as specified by the safety basis of the storage facility through the duration of the storage period, which is typically well beyond the one year transportation window. Test programs have been established to obtain aging data on materials of construction that are the most sensitive/susceptible to aging in certain shipping package designs. The collective data are being used to support extending the service life of shipping packages in both transportation and storage.
Date: June 12, 2012
Creator: Dunn, K.; Abramczyk, G.; Bellamy, S.; Daugherty, W.; Hackney, B.; Hoffman, E. et al.
Object Type: Article
System: The UNT Digital Library
Final Report for proposal "The Interface between Earth System Models and Impacts on Society Workshop, Spring 2011 (open access)

Final Report for proposal "The Interface between Earth System Models and Impacts on Society Workshop, Spring 2011

The creation of a new Community Earth System Model (CESM) working group, combining science-driven research with user-driven requirements, will further broaden the CESM user base and will considerably enrich the project by building formal links to sectoral scientists and decision makers. The first step in this process is a small (~25 person) workshop to identify the goals and objectives of the new working group, to discuss how it will interact with existing CESM working groups, and to identify a few, initial pilot projects to explore how to use climate information to manage climate risk more effectively. This proposal is to support the travel costs of non-NCAR participants in this planning workshop.
Date: June 12, 2012
Creator: Hurrell, Jim
Object Type: Report
System: The UNT Digital Library
Biorefinery and Hydrogen Fuel Cell Research (open access)

Biorefinery and Hydrogen Fuel Cell Research

In this project we focused on several aspects of technology development that advances the formation of an integrated biorefinery. These focus areas include: [1] establishment of pyrolysis processing systems and characterization of the product oils for fuel applications, including engine testing of a preferred product and its pro forma economic analysis; [2] extraction of sugars through a novel hotwater extaction process, and the development of levoglucosan (a pyrolysis BioOil intermediate); [3] identification and testing of the use of biochar, the coproduct from pyrolysis, for soil applications; [4] developments in methods of atomic layer epitaxy (for efficient development of coatings as in fuel cells); [5] advancement in fermentation of lignocellulosics, [6] development of algal biomass as a potential substrate for the biorefinery, and [7] development of catalysts from coproducts. These advancements are intended to provide a diverse set of product choices within the biorefinery, thus improving the cost effectiveness of the system. Technical effectiveness was demonstrated in the pyrolysis biooil based diesel fuel supplement, sugar extraction from lignocelluose, use of biochar, production of algal biomass in wastewaters, and the development of catalysts. Economic feasibility of algal biomass production systems seems attractive, relative to the other options. However, further optimization in all …
Date: June 12, 2012
Creator: Das, K. C.; Adams, Thomas T.; Eiteman, Mark A.; Stickney, John; Peterson, Joy Doran; Kastner, James R. et al.
Object Type: Report
System: The UNT Digital Library
HIGH-GRADIENT, HIGH-TRANSFORMER-RATIO, DIELECTRIC WAKE FIELD ACCELERATOR (open access)

HIGH-GRADIENT, HIGH-TRANSFORMER-RATIO, DIELECTRIC WAKE FIELD ACCELERATOR

The Phase I work reported here responds to DoE'ss stated need "...to develop improved accelerator designs that can provide very high gradient (>200 MV/m for electrons...) acceleration of intense bunches of particles." Omega-P'™s approach to this goal is through use of a ramped train of annular electron bunches to drive a coaxial dielectric wakefield accelerator (CDWA) structure. This approach is a direct extension of the CDWA concept from acceleration in wake fields caused by a single drive bunch, to the more efficient acceleration that we predict can be realized from a tailored (or ramped) train of several drive bunches. This is possible because of a much higher transformer ratio for the latter. The CDWA structure itself has a number of unique features, including: a high accelerating gradient G, potentially with G > 1 GeV/m; continuous energy coupling from drive to test bunches without transfer structures; inherent transverse focusing forces for particles in the accelerated bunch; highly stable motion of high charge annular drive bunches; acceptable alignment tolerances for a multi-section system. What is new in the present approach is that the coaxial dielectric structure is now to be energized by-not one-”but by a short train of ramped annular-shaped drive bunches …
Date: April 12, 2012
Creator: Hirshfield, Jay L.
Object Type: Report
System: The UNT Digital Library