2008 Summer Research Institute Interfacial and Condensed Phase Chemical Physics Annual Report (open access)

2008 Summer Research Institute Interfacial and Condensed Phase Chemical Physics Annual Report

For the fifth year, the Pacific Northwest National Laboratory in Richland, Washington, invited graduate students, postdoctoral fellows, university faculty, and students entering graduate students from around the world to participate in the Summer Research Institute in Interfacial and Condensed Phase Chemical Physics. The institute offers participants the opportunity to gain hands-on experience in top-notch research laboratories while working along internationally respected mentors. Of the 38 applicants, 20 were accepted for the 8- to 10-week program. The participants came from universities as close as Seattle and Portland and as far away as Germany and Singapore. At Pacific Northwest National Laboratory, the 20 participants were mentored by 13 scientists. These mentors help tailor the participant’s experience to the needs of that person. Further, the mentors provide guidance on experimental and theoretical techniques, research design and completion, and other aspects of scientific careers in interfacial and condensed phase chemical physics. The research conducted at the institute can result in tangible benefits for the participants. For example, many have co-authored papers that have been published in peer-reviewed journals, including top-rated journals such as Science. Also, they have presented their research at conferences, such as the Gordon Research Conference on Dynamics at Surfaces and the …
Date: November 1, 2008
Creator: Garrett, Bruce C.; Tonkyn, Russell G. & Avery, Nachael B.
Object Type: Report
System: The UNT Digital Library
21st Century Locomotive Technology: Quarterly Technical Status Report 23 DOE/AL68284-TSR23 (open access)

21st Century Locomotive Technology: Quarterly Technical Status Report 23 DOE/AL68284-TSR23

sodium battery heat release parameters were determined experimentally
Date: November 3, 2008
Creator: Salasoo, Lembit
Object Type: Report
System: The UNT Digital Library
Accelerated Stress Testing and Diagnostic Analysis of Degradation in CdTe Solar Cells (open access)

Accelerated Stress Testing and Diagnostic Analysis of Degradation in CdTe Solar Cells

The primary goal of this study was to ascertain the presence and types of mechanisms affecting CdS/CdTe device stability in the temperature range of 60 to 120 ..deg..C. It should be noted that the results presented were specific to cells made using the specific growth conditions described.
Date: November 1, 2008
Creator: Albin, D. S.
Object Type: Article
System: The UNT Digital Library
Accelerating scientific discovery : 2007 annual report. (open access)

Accelerating scientific discovery : 2007 annual report.

As a gateway for scientific discovery, the Argonne Leadership Computing Facility (ALCF) works hand in hand with the world's best computational scientists to advance research in a diverse span of scientific domains, ranging from chemistry, applied mathematics, and materials science to engineering physics and life sciences. Sponsored by the U.S. Department of Energy's (DOE) Office of Science, researchers are using the IBM Blue Gene/L supercomputer at the ALCF to study and explore key scientific problems that underlie important challenges facing our society. For instance, a research team at the University of California-San Diego/ SDSC is studying the molecular basis of Parkinson's disease. The researchers plan to use the knowledge they gain to discover new drugs to treat the disease and to identify risk factors for other diseases that are equally prevalent. Likewise, scientists from Pratt & Whitney are using the Blue Gene to understand the complex processes within aircraft engines. Expanding our understanding of jet engine combustors is the secret to improved fuel efficiency and reduced emissions. Lessons learned from the scientific simulations of jet engine combustors have already led Pratt & Whitney to newer designs with unprecedented reductions in emissions, noise, and cost of ownership. ALCF staff members provide …
Date: November 14, 2008
Creator: Beckman, P.; Dave, P. & Drugan, C.
Object Type: Report
System: The UNT Digital Library
Accessing tri-gluon correlations in the nucleon via the singlespin asymmetry in open charm production (open access)

Accessing tri-gluon correlations in the nucleon via the singlespin asymmetry in open charm production

We calculate the single transverse-spin asymmetry for open charm production in pp collisions within the QCD collinear factorization approach. We include contributions from both twist-three quark-gluon and tri-gluon correlation functions. We find that the quark-gluon correlation functions alone generate only a very small asymmetry for open charm production in the kinematic region of current interest at RHIC, so that the observation of any significant single-spin asymmetry would be a clear indication of the presence of tri-gluon correlations inside a polarized proton. We furthermore demonstrate that the tri-gluon contribution could be very different for the production of D and \bar{D} mesons. These features make the single spin asymmetry in open charm production in polarized pp collisions at RHIC an excellent probe of tri-gluon correlation functions.
Date: November 14, 2008
Creator: Kang, Zhong-Bo; Qiu, Jian-Wei; Vogelsang, Werner & Yuan, Feng
Object Type: Article
System: The UNT Digital Library
Acclerator R&D for a Linear Collider (open access)

Acclerator R&D for a Linear Collider

The goal of this project was to perform simulations of beam transport in linear colliders, with an emphasis on emittance dilution, spin polarization transport, and development and testing of beam based tuning algorithms. Our simulations are based on an existing object-oriented particle-tracking library, Bmad. To facilitate the efficient development of simulations, an accelerator design and analysis program based on Bmad has been developed called Tao (Tool for Accelerator Optics). The three beam-based alignment algorithms, Dispersion Free Steering, Ballistic Alignment (BA), and the Kubo Method have been implemented in Tao. We have studied the effects of magnet misalignments, BPM resolution, beam jitter, stray fields, BPM and steering magnet failure and the effects of various cavity shape wakefields. A parametric study has been conducted in the presence of the above types of errors for all three alignment algorithms. We find that BPM resolution has only modest impact on the effectiveness of beam based alignment. The DFS correction algorithm was found to be very robust in situations where there were BPM and/or steering magnet failures. The wakefields in the main linac are very weak and cause negligible emittance growth. Spin tracking was extended to study all accelerator components between the damping ring and …
Date: November 26, 2008
Creator: Rubin, D.L.; Dugan, G.; Gibbons, L.; Palmer, M.; Patterson, R.; Sagan, D. et al.
Object Type: Report
System: The UNT Digital Library
AdS/QCD and Its Holographic Light-Front Partonic Representation (open access)

AdS/QCD and Its Holographic Light-Front Partonic Representation

Starting from the Hamiltonian equation of motion in QCD we find a single variable light-front equation for QCD which determines the eigenspectrum and the light-front wavefunctions of hadrons for general spin and orbital angular momentum. This light-front wave equation is equivalent to the equations of motion which describe the propagation of spin-J modes on anti-de Sitter (AdS) space.
Date: November 12, 2008
Creator: de Teramond, Guy F. & Brodsky, Stanley J.
Object Type: Article
System: The UNT Digital Library
Advanced Coal Wind Hybrid: Economic Analysis (open access)

Advanced Coal Wind Hybrid: Economic Analysis

Growing concern over climate change is prompting new thinking about the technologies used to generate electricity. In the future, it is possible that new government policies on greenhouse gas emissions may favor electric generation technology options that release zero or low levels of carbon emissions. The Western U.S. has abundant wind and coal resources. In a world with carbon constraints, the future of coal for new electrical generation is likely to depend on the development and successful application of new clean coal technologies with near zero carbon emissions. This scoping study explores the economic and technical feasibility of combining wind farms with advanced coal generation facilities and operating them as a single generation complex in the Western US. The key questions examined are whether an advanced coal-wind hybrid (ACWH) facility provides sufficient advantages through improvements to the utilization of transmission lines and the capability to firm up variable wind generation for delivery to load centers to compete effectively with other supply-side alternatives in terms of project economics and emissions footprint. The study was conducted by an Analysis Team that consists of staff from the Lawrence Berkeley National Laboratory (LBNL), National Energy Technology Laboratory (NETL), National Renewable Energy Laboratory (NREL), and …
Date: November 28, 2008
Creator: Phadke, Amol; Goldman, Charles; Larson, Doug; Carr, Tom; Rath, Larry; Balash, Peter et al.
Object Type: Report
System: The UNT Digital Library
Advanced Mixing Models (open access)

Advanced Mixing Models

The process of recovering the waste in storage tanks at the Savannah River Site (SRS) typically requires mixing the contents of the tank with one to four dual-nozzle jet mixers located within the tank. The typical criteria to establish a mixed condition in a tank are based on the number of pumps in operation and the time duration of operation. To ensure that a mixed condition is achieved, operating times are set conservatively long. This approach results in high operational costs because of the long mixing times and high maintenance and repair costs for the same reason. A significant reduction in both of these costs might be realized by reducing the required mixing time based on calculating a reliable indicator of mixing with a suitably validated computer code. The work described in this report establishes the basis for further development of the theory leading to the identified mixing indicators, the benchmark analyses demonstrating their consistency with widely accepted correlations, and the application of those indicators to SRS waste tanks to provide a better, physically based estimate of the required mixing time. Waste storage tanks at SRS contain settled sludge which varies in height from zero to 10 ft. The sludge …
Date: November 13, 2008
Creator: Lee, S.; Richard Dimenna, R. & David Tamburello, D.
Object Type: Report
System: The UNT Digital Library
Advanced Power Electronic Interfaces for Distributed Energy Systems, Part 2: Modeling, Development, and Experimental Evaluation of Advanced Control Functions for Single-Phase Utility-Connected Inverter (open access)

Advanced Power Electronic Interfaces for Distributed Energy Systems, Part 2: Modeling, Development, and Experimental Evaluation of Advanced Control Functions for Single-Phase Utility-Connected Inverter

Integrating renewable energy and distributed generations into the Smart Grid architecture requires power electronic (PE) for energy conversion. The key to reaching successful Smart Grid implementation is to develop interoperable, intelligent, and advanced PE technology that improves and accelerates the use of distributed energy resource systems. This report describes the simulation, design, and testing of a single-phase DC-to-AC inverter developed to operate in both islanded and utility-connected mode. It provides results on both the simulations and the experiments conducted, demonstrating the ability of the inverter to provide advanced control functions such as power flow and VAR/voltage regulation. This report also analyzes two different techniques used for digital signal processor (DSP) code generation. Initially, the DSP code was written in C programming language using Texas Instrument's Code Composer Studio. In a later stage of the research, the Simulink DSP toolbox was used to self-generate code for the DSP. The successful tests using Simulink self-generated DSP codes show promise for fast prototyping of PE controls.
Date: November 1, 2008
Creator: Chakraborty, S.; Kroposki, B. & Kramer, W.
Object Type: Report
System: The UNT Digital Library
Advanced Techniques for Power System Identification from Measured Data (open access)

Advanced Techniques for Power System Identification from Measured Data

Time-synchronized measurements provide rich information for estimating a power-system's electromechanical modal properties via advanced signal processing. This information is becoming critical for the improved operational reliability of interconnected grids. A given mode's properties are described by its frequency, damping, and shape. Modal frequencies and damping are useful indicators of power-system stress, usually declining with increased load or reduced grid capacity. Mode shape provides critical information for operational control actions. This project investigated many advanced techniques for power system identification from measured data focusing on mode frequency and damping ratio estimation. Investigators from the three universities coordinated their effort with Pacific Northwest National Laboratory (PNNL). Significant progress was made on developing appropriate techniques for system identification with confidence intervals and testing those techniques on field measured data and through simulation. Experimental data from the western area power system was provided by PNNL and Bonneville Power Administration (BPA) for both ambient conditions and for signal injection tests. Three large-scale tests were conducted for the western area in 2005 and 2006. Measured field PMU (Phasor Measurement Unit) data was provided to the three universities. A 19-machine simulation model was enhanced for testing the system identification algorithms. Extensive simulations were run with this model …
Date: November 25, 2008
Creator: Pierre, John W.; Wies, Richard & Trudnowski, Daniel
Object Type: Report
System: The UNT Digital Library
AFC-1 Fuel Rodlet Fission Power Deposition Validation in ATR (open access)

AFC-1 Fuel Rodlet Fission Power Deposition Validation in ATR

One of the viable options of long-term geological disposal of the nuclear power reactors generated spent fuel is to extract plutonium, the minor actinides (MA) and potentially long-lived fission products from the spent fuel and transmute them into short-lived or stable radionuclides in an appropriate reactor for the reduction of the radiological toxicity of the nuclear waste stream. An important component of that technology will be a non-fertile / low-fertile actinide transmutation fuel form containing the plutonium, neptunium, americium (and possibly curium) isotopes to be transmuted. Such advanced fuel forms, especially ones enriched in the long-life minor actinide (LLMA) elements (i.e., Np, Am, Cm), have minimal irradiation performance data available from which to establish a transmutation fuel form design. Recognizing these needs, an Advanced Fuel Cycle test series-1 (AFC-1) irradiation test on a variety of candidate fuel forms is now being conducted in Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL). The first advanced fuel experiment (AFC-1) has been finalized and the test assembly analyzed for insertion and irradiation in ATR. The ATR core consists of a serpentine and rotationally symmetric fuel assembly about the z-axis of the core center. The plan view of the ATR core configuration …
Date: November 1, 2008
Creator: Chang, G. S.; Lillo, M. A. & Utterbeck, D. J.
Object Type: Article
System: The UNT Digital Library
ALSNews 2008 (open access)

ALSNews 2008

Compilation of Advanced Light Source newsletter, ALSNews, for 2008, Volumes 283-293.
Date: November 26, 2008
Creator: McCullough (Ed.), Julie & Tamura (Ed.), Lori
Object Type: Report
System: The UNT Digital Library
Analysis of Cost-Effective Off-Board Hydrogen Storage and Refueling Stations (open access)

Analysis of Cost-Effective Off-Board Hydrogen Storage and Refueling Stations

This report highlights design and component selection considerations for compressed gas hydrogen fueling stations operating at 5000 psig or 350 bar. The primary focus is on options for compression and storage – in terms of practical equipment options as well as various system configurations and how they influence delivery performance and station economics.
Date: November 14, 2008
Creator: Barnes, Ted & Liss, William
Object Type: Report
System: The UNT Digital Library
Analysis on the Density Driven Air-Ingress Accident in VHTRs (open access)

Analysis on the Density Driven Air-Ingress Accident in VHTRs

Air-ingress following the pipe rupture is considered to be the most serious accident in the VHTRs due to its potential problems such as core heat-up, structural integrity and toxic gas release. Previously, it has been believed that the main air-ingress mechanism of this accident is the molecular diffusion process between the reactor core and the cavity. However, according to some recent studies, there is another fast air-ingress process that has not been considered before. It is called density-driven stratified flow. The potential for density-driven stratified air ingress into the VHTR following a large-break LOCA was first described in the NGNP Methods Technical Program based on stratified flow studies performed with liquid. Studies on densitygradient driven stratified flow in advanced reactor systems has been the subject of active research for well over a decade since density-gradient dominated stratified flow is an inherent characteristic of passive systems used in advanced reactors. Recently, Oh et al. performed a CFD analysis on the stratified flow in the VHTR, and showed that this effect can significantly accelerate the air-ingress process in the VHTRs. They also proposed to replace the original air-ingress scenario based on the molecular diffusion with the one based on the stratified flow. …
Date: November 1, 2008
Creator: Kim, Eung Soo; Oh, Chang; Schultz, Richard & Petti, David
Object Type: Article
System: The UNT Digital Library
Analytical Data Report of Grab Samples Collected From 216-A-5 Crib (open access)

Analytical Data Report of Grab Samples Collected From 216-A-5 Crib

This is an analytical data report for sample recieved from 216-A-5 crib
Date: November 21, 2008
Creator: Lindberg, Michael J.
Object Type: Report
System: The UNT Digital Library
Application of Time-Lapse Seismic Monitoring for the Control and Optimization of CO2 Enhanced Oil Recovery Operations (open access)

Application of Time-Lapse Seismic Monitoring for the Control and Optimization of CO2 Enhanced Oil Recovery Operations

This project, 'Application of Time-Lapse Seismic Monitoring for the Control and Optimization of CO{sub 2} Enhanced Oil Recovery Operations', investigated the potential for monitoring CO{sub 2} floods in carbonate reservoirs through the use of standard p-wave seismic data. This primarily involved the use of 4D seismic (time lapse seismic) in an attempt to observe and map the movement of the injected CO{sub 2} through a carbonate reservoir. The differences between certain seismic attributes, such as amplitude, were used for this purpose. This technique has recently been shown to be effective in CO{sub 2} monitoring in Enhanced Oil Recovery (EOR) projects, such as Weyborne. This study was conducted in the Charlton 30/31 field in the northern Michigan Basin, which is a Silurian pinnacle reef that completed its primary production in 1997 and was scheduled for enhanced oil recovery using injected CO{sub 2}. Prior to injection an initial 'Base' 3D survey was obtained over the field and was then processed and interpreted. CO{sub 2} injection within the main portion of the reef was conducted intermittently during 13 months starting in August 2005. During this time, 29,000 tons of CO{sub 2} was injected into the Guelph formation, historically known as the Niagaran Brown …
Date: November 30, 2008
Creator: Toelle, Brian
Object Type: Report
System: The UNT Digital Library
April 2008 Monitoring Report for Morrill, Kansas. (open access)

April 2008 Monitoring Report for Morrill, Kansas.

In September 2005, the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) initiated periodic sampling of groundwater in the vicinity of a grain storage facility formerly operated by the CCC/USDA at Morrill, Kansas. The sampling at Morrill is being performed on behalf of the CCC/USDA by Argonne National Laboratory, in accord with a monitoring program approved by the Kansas Department of Health and Environment (KDHE), to monitor levels of carbon tetrachloride contamination identified in the groundwater at this site (Argonne 2004, 2005a). This report provides results for the most recent monitoring event, in April 2008. Under the KDHE-approved monitoring plan (Argonne 2005b), groundwater was initially sampled twice yearly for a recommended period of two years (in fall 2005, in spring and fall 2006, and in spring and fall 2007). The samples were analyzed for volatile organic compounds (VOCs), as well as for selected geochemical parameters to aid in the evaluation of possible natural contaminant degradation (reductive dechlorination) processes in the subsurface environment. During the recommended two-year period, the originally approved scope of the monitoring was expanded to include vegetation sampling (initiated in October 2006) and surface water and stream bed sediment sampling (initiated in March 2007, after a …
Date: November 4, 2008
Creator: LaFreniere, L. M.
Object Type: Report
System: The UNT Digital Library
The Arctic as a test case for an assessment of climate impacts on national security. (open access)

The Arctic as a test case for an assessment of climate impacts on national security.

The Arctic region is rapidly changing in a way that will affect the rest of the world. Parts of Alaska, western Canada, and Siberia are currently warming at twice the global rate. This warming trend is accelerating permafrost deterioration, coastal erosion, snow and ice loss, and other changes that are a direct consequence of climate change. Climatologists have long understood that changes in the Arctic would be faster and more intense than elsewhere on the planet, but the degree and speed of the changes were underestimated compared to recent observations. Policy makers have not yet had time to examine the latest evidence or appreciate the nature of the consequences. Thus, the abruptness and severity of an unfolding Arctic climate crisis has not been incorporated into long-range planning. The purpose of this report is to briefly review the physical basis for global climate change and Arctic amplification, summarize the ongoing observations, discuss the potential consequences, explain the need for an objective risk assessment, develop scenarios for future change, review existing modeling capabilities and the need for better regional models, and finally to make recommendations for Sandia's future role in preparing our leaders to deal with impacts of Arctic climate change on …
Date: November 1, 2008
Creator: Taylor, Mark A.; Zak, Bernard Daniel; Backus, George A.; Ivey, Mark D. & Boslough, Mark Bruce Elrick
Object Type: Report
System: The UNT Digital Library
Asymptotically Optimal High-Order Accurate Algorithms for the Solution of Certain Elliptic PDEs (open access)

Asymptotically Optimal High-Order Accurate Algorithms for the Solution of Certain Elliptic PDEs

The main goal of the project, "Asymptotically Optimal, High-Order Accurate Algorithms for the Solution of Certain Elliptic PDE's" (DE-FG02-03ER25577) was to develop fast, high-order algorithms for the solution of scattering problems and spectral problems of photonic crystals theory. The results we obtained lie in three areas: (1) asymptotically fast, high-order algorithms for the solution of eigenvalue problems of photonics, (2) fast, high-order algorithms for the solution of acoustic and electromagnetic scattering problems in the inhomogeneous media, and (3) inversion formulas and fast algorithms for the inverse source problem for the acoustic wave equation, with applications to thermo- and opto- acoustic tomography.
Date: November 26, 2008
Creator: Kunyansky, Leonid
Object Type: Report
System: The UNT Digital Library
Atmospheric Inverse Estimates of Methane Emissions from Central California (open access)

Atmospheric Inverse Estimates of Methane Emissions from Central California

Methane mixing ratios measured at a tall-tower are compared to model predictions to estimate surface emissions of CH{sub 4} in Central California for October-December 2007 using an inverse technique. Predicted CH{sub 4} mixing ratios are calculated based on spatially resolved a priori CH{sub 4} emissions and simulated atmospheric trajectories. The atmospheric trajectories, along with surface footprints, are computed using the Weather Research and Forecast (WRF) coupled to the Stochastic Time-Inverted Lagrangian Transport (STILT) model. An uncertainty analysis is performed to provide quantitative uncertainties in estimated CH{sub 4} emissions. Three inverse model estimates of CH{sub 4} emissions are reported. First, linear regressions of modeled and measured CH{sub 4} mixing ratios obtain slopes of 0.73 {+-} 0.11 and 1.09 {+-} 0.14 using California specific and Edgar 3.2 emission maps respectively, suggesting that actual CH{sub 4} emissions were about 37 {+-} 21% higher than California specific inventory estimates. Second, a Bayesian 'source' analysis suggests that livestock emissions are 63 {+-} 22% higher than the a priori estimates. Third, a Bayesian 'region' analysis is carried out for CH{sub 4} emissions from 13 sub-regions, which shows that inventory CH{sub 4} emissions from the Central Valley are underestimated and uncertainties in CH{sub 4} emissions are reduced …
Date: November 21, 2008
Creator: Zhao, Chuanfeng; Andrews, Arlyn E.; Bianco, Laura; Eluszkiewicz, Janusz; Hirsch, Adam; MacDonald, Clinton et al.
Object Type: Article
System: The UNT Digital Library
Auto-DR and Pre-cooling of Buildings at Tri-City Corporate Center (open access)

Auto-DR and Pre-cooling of Buildings at Tri-City Corporate Center

Over the several past years, Lawrence Berkeley National Laboratory (LBNL) has conducted field tests for different pre-cooling strategies in different commercial buildings within California. The test results indicated that pre-cooling strategies were effective in reducing electric demand in these buildings during peak periods. This project studied how to optimize pre-cooling strategies for eleven buildings in the Tri-City Corporate Center, San Bernardino, California with the assistance of a building energy simulation tool -- the Demand Response Quick Assessment Tool (DRQAT) developed by LBNL's Demand Response Research Center funded by the California Energy Commission's Public Interest Energy Research (PIER) Program. From the simulation results of these eleven buildings, optimal pre-cooling and temperature reset strategies were developed. The study shows that after refining and calibrating initial models with measured data, the accuracy of the models can be greatly improved and the models can be used to predict load reductions for automated demand response (Auto-DR) events. This study summarizes the optimization experience of the procedure to develop and calibrate building models in DRQAT. In order to confirm the actual effect of demand response strategies, the simulation results were compared to the field test data. The results indicated that the optimal demand response strategies worked …
Date: November 1, 2008
Creator: Yin, Rongxin; Xu, Peng & Kiliccote, Sila
Object Type: Report
System: The UNT Digital Library
Automated Demand Response Opportunities in Wastewater Treatment Facilities (open access)

Automated Demand Response Opportunities in Wastewater Treatment Facilities

Wastewater treatment is an energy intensive process which, together with water treatment, comprises about three percent of U.S. annual energy use. Yet, since wastewater treatment facilities are often peripheral to major electricity-using industries, they are frequently an overlooked area for automated demand response opportunities. Demand response is a set of actions taken to reduce electric loads when contingencies, such as emergencies or congestion, occur that threaten supply-demand balance, and/or market conditions occur that raise electric supply costs. Demand response programs are designed to improve the reliability of the electric grid and to lower the use of electricity during peak times to reduce the total system costs. Open automated demand response is a set of continuous, open communication signals and systems provided over the Internet to allow facilities to automate their demand response activities without the need for manual actions. Automated demand response strategies can be implemented as an enhanced use of upgraded equipment and facility control strategies installed as energy efficiency measures. Conversely, installation of controls to support automated demand response may result in improved energy efficiency through real-time access to operational data. This paper argues that the implementation of energy efficiency opportunities in wastewater treatment facilities creates a base …
Date: November 19, 2008
Creator: Thompson, Lisa; Song, Katherine; Lekov, Alex & McKane, Aimee
Object Type: Article
System: The UNT Digital Library
Beam dynamics studies of the 8 GeV Linac at FNAL (open access)

Beam dynamics studies of the 8 GeV Linac at FNAL

The proposed 8-GeV proton driver (PD) linac at FNAL includes a front end up to {approx}420 MeV operating at 325 MHz and a high energy section at 1300 MHz. A normal conducting RFQ and short CH type resonators are being developed for the initial acceleration of the H-minus or proton beam up to 10 MeV. From 10 MeV to {approx}420 MeV, the voltage gain is provided by superconducting (SC) spoke-loaded cavities. In the high-energy section, the acceleration will be provided by the International Linear Collider (ILC)-style SC elliptical cell cavities. To employ existing, readily available klystrons, an RF power fan out from high-power klystrons to multiple cavities is being developed. The beam dynamics simulation code TRACK, available in both serial and parallel versions, has been updated to include all known H-minus stripping mechanisms to predict the exact location of beam losses. An iterative simulation procedure is being developed to interact with a transient beam loading model taking into account RF feedback and feedforward systems.
Date: November 1, 2008
Creator: Ostroumov, P.N.; Mustapha, B.; /Argonne; Carneiro, J.-P. & /Fermilab
Object Type: Article
System: The UNT Digital Library