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Bunch Length Monitoring at the A0 Photoinjector Using a Quasi-Optical Schottky Detector (open access)

Bunch Length Monitoring at the A0 Photoinjector Using a Quasi-Optical Schottky Detector

Noninvasive bunch duration monitoring has a crucial importance for modern accelerators intended for short wavelength FEL's, colliders and in some beam dynamics experiments. Monitoring of the bunch compression in the Emittance Exchange Experiment at the A0 Photoinjector was done using a parametric presentation of the bunch duration via Coherent Synchrotron Radiation (CSR) emitted in a dipole magnet and measured with a wideband quasi-optical Schottky Barrier Detector (SBD). The monitoring resulted in a mapping of the quadrupole parameters allowing a determination of the region of highest compression of the bunch in the sub-picosecond range. The obtained data were compared with those measured using the streak camera. A description of the technique and the results of simulations and measurements are presented and discussed in this report.
Date: May 1, 2009
Creator: Kazakevich, G.; Davidsaver, M.; Edwards, H.; Fliller, R.; Koeth, T.; Lumpkin, A. et al.
Object Type: Article
System: The UNT Digital Library
Buoyancy-Driven Ventilation of Hydrogen from Buildings: Laboratory Test and Model Validation (open access)

Buoyancy-Driven Ventilation of Hydrogen from Buildings: Laboratory Test and Model Validation

Passive, buoyancy-driven ventilation is one approach to limiting hydrogen concentration. We explored the relationship between leak rate, ventilation design, and hydrogen concentrations.
Date: May 1, 2009
Creator: Barley, C. D. & Gawlik, K.
Object Type: Report
System: The UNT Digital Library
Capabilities to Support Thermochemical Hydrogen Production Technology Development (open access)

Capabilities to Support Thermochemical Hydrogen Production Technology Development

This report presents the results of a study to determine if Idaho National Laboratory (INL) has the skilled staff, instrumentation, specialized equipment, and facilities required to take on work in thermochemical research, development, and demonstration currently being performed by the Nuclear Hydrogen Initiative (NHI). This study outlines the beneficial collaborations between INL and other national laboratories, universities, and industries to strengthen INL's thermochemical efforts, which should be developed to achieve the goals of the NHI in the most expeditious, cost effective manner. Taking on this work supports INL's long-term strategy to maintain leadership in thermochemical cycle development. This report suggests a logical path forward to accomplish this transition.
Date: May 1, 2009
Creator: Ginosar, Daniel M.
Object Type: Report
System: The UNT Digital Library
The CEBAF Master Oscillator and Distribution Remodeling (open access)

The CEBAF Master Oscillator and Distribution Remodeling

Jefferson Lab’s CEBAF accelerator operation requires various frequency references to be distributed along the site. Three signals: 10 MHz, 70 MHz and 499 MHz are synthesized in the Machine Control Center (MCC) while 1427 MHz and 429 MHz are derived from 499 MHz and 70 MHz signals in four separate locations. We are replacing our obsolete 10 MHz, 70 MHz and 499 MHz sources with new sources that will incorporate a GPS receiver to discipline a 10 MHz reference. In addition the MO (Master Oscillator) system will be redundant (duplicate MO) and a third signal source will be used as a system diagnostic. Moreover, the 12 GeV Energy Upgrade for CEBAF accelerator will be adding 80 new RF systems. To support them the distribution of 1427 MHz and 70 MHz signals has to be extended and be able to deliver enough LO (Local Oscillator) and IF (Intermediate Frequency) power to 320 old and 80 new 80 RF systems. This paper discusses the new MO and the drive line extension.
Date: May 1, 2009
Creator: Tomasz Plawski, J. Hovater, John Musson, Ramakrishna Bachimanchi
Object Type: Article
System: The UNT Digital Library
Challenges for the CMS computing model in the first year (open access)

Challenges for the CMS computing model in the first year

CMS is in the process of commissioning a complex detector and a globally distributed computing infrastructure simultaneously. This represents a unique challenge. Even at the beginning there is not sufficient analysis or organized processing resources at CERN alone. In this presentation we discuss the unique computing challenges CMS expects to face during the first year of running and how they influence the baseline computing model decisions. During the early accelerator commissioning periods, CMS will attempt to collect as many events as possible when the beam is on in order to provide adequate early commissioning data. Some of these plans involve overdriving the Tier-0 infrastructure during data collection with recovery when the beam is off. In addition to the larger number of triggered events, there will be pressure in the first year to collect and analyze more complete data formats as the summarized formats mature. The large event formats impact the required storage, bandwidth, and processing capacity across all the computing centers. While the understanding of the detector and the event selections is being improved, there will likely be a larger number of reconstruction passes and skims performed by both central operations and individual users. We discuss how these additional stresses …
Date: May 1, 2009
Creator: Fisk, I.
Object Type: Article
System: The UNT Digital Library

Characterization and Development of Advanced Heat Transfer Technologies

This presentation gives an overview of the status and FY09 accomplishments for the NREL thermal management research project 'Characterization and Development of Advanced Heat Transfer Technologies'.
Date: May 1, 2009
Creator: Kelly, K.
Object Type: Presentation
System: The UNT Digital Library
Circularly Inclined Solenoid Channel for 6D Ionization Cooling of Muons (open access)

Circularly Inclined Solenoid Channel for 6D Ionization Cooling of Muons

Ionization cooling is essential for realization of Muon Collider, muons beam based neutrino factories and other experiments involving muons. The simplest structure - absorber(s) immersed in alternating solenoidal magnetic field - provides only transverse cooling since the longitudinal motion in the most suitable momentum range (2-300MeV/c) is naturally anti-damped. To overcome this difficulty it is proposed to periodically tilt solenoids so that a rotating transverse magnetic field was created. By choosing the phase advance per period above a multiple of 2{pi} it is possible to ensure that muons with higher momentum make a longer path in the absorber (whether distributed or localized) thus providing longitudinal damping. Basic theory of such channel and results of tracking simulations are presented.
Date: May 1, 2009
Creator: Alexahin, Y.
Object Type: Article
System: The UNT Digital Library
A code inspection process for security reviews (open access)

A code inspection process for security reviews

In recent years, it has become more and more evident that software threat communities are taking an increasing interest in Grid infrastructures. To mitigate the security risk associated with the increased numbers of attacks, the Grid software development community needs to scale up effort to reduce software vulnerabilities. This can be achieved by introducing security review processes as a standard project management practice. The Grid Facilities Department of the Fermilab Computing Division has developed a code inspection process, tailored to reviewing security properties of software. The goal of the process is to identify technical risks associated with an application and their impact. This is achieved by focusing on the business needs of the application (what it does and protects), on understanding threats and exploit communities (what an exploiter gains), and on uncovering potential vulnerabilities (what defects can be exploited). The desired outcome of the process is an improvement of the quality of the software artifact and an enhanced understanding of possible mitigation strategies for residual risks. This paper describes the inspection process and lessons learned on applying it to Grid middleware.
Date: May 1, 2009
Creator: Garzoglio, Gabriele
Object Type: Article
System: The UNT Digital Library
Collaborating at a distance: operations centres, tools, and trends (open access)

Collaborating at a distance: operations centres, tools, and trends

Successful operation of the LHC and its experiments is crucial to the future of the worldwide high-energy physics program. Remote operations and monitoring centres have been established for the CMS experiment in several locations around the world. The development of remote centres began with the LHC{at}FNAL ROC and has evolved into a unified approach with distributed centres that are collectively referred to as 'CMS Centres Worldwide'. An overview of the development of remote centres for CMS will be presented, along with a synopsis of collaborative tools that are used in these centres today and trends in the development of remote operations capabilities for high-energy physics.
Date: May 1, 2009
Creator: Gottschalk, Erik E.
Object Type: Article
System: The UNT Digital Library
Comparative Analysis of Three Proposed Federal Renewable Electricity Standards (open access)

Comparative Analysis of Three Proposed Federal Renewable Electricity Standards

This paper analyzes potential impacts of proposed national renewable electricity standard (RES) legislation. An RES is a mandate requiring certain electricity retailers to provide a minimum share of their electricity sales from qualifying renewable power generation. The analysis focuses on draft bills introduced individually by Senator Jeff Bingaman and Representative Edward Markey, and jointly by Representative Henry Waxman and Markey. The analysis uses NREL's Regional Energy Deployment System (ReEDS) model to evaluate the impacts of the proposed RES requirements on the U.S. energy sector in four scenarios.
Date: May 1, 2009
Creator: Sullivan, Patrick; Logan, Jeffrey; Bird, Lori & Short, Walter
Object Type: Report
System: The UNT Digital Library
A COMPARISON OF PEBBLE MIXING AND DEPLETION ALGORITHMS USED IN PEBBLE-BED REACTOR EQUILIBRIUM CYCLE SIMULATION (open access)

A COMPARISON OF PEBBLE MIXING AND DEPLETION ALGORITHMS USED IN PEBBLE-BED REACTOR EQUILIBRIUM CYCLE SIMULATION

Recirculating pebble-bed reactors are distinguished from all other reactor types by the downward movement through and reinsertion of fuel into the core during operation. Core simulators must account for this movement and mixing in order to capture the physics of the equilibrium cycle core. VSOP and PEBBED are two codes used to perform such simulations, but they do so using different methods. In this study, a simplified pebble-bed core with a specified flux profile and cross sections is used as the model for conducting analyses of two types of burnup schemes. The differences between the codes are described and related to the differences observed in the nuclide densities in pebbles discharged from the core. Differences in the methods for computing fission product buildup and average number densities lead to significant differences in the computed core power and eigenvalue. These test models provide a key component of an overall equilibrium cycle benchmark involving neutron transport, cross section generation, and fuel circulation.
Date: May 1, 2009
Creator: Gougar, Hans D.; Reitsma, Frederik & Joubert, Wessel
Object Type: Article
System: The UNT Digital Library
Compton Backscattering Concept for the Production of Molybdenum-99 (open access)

Compton Backscattering Concept for the Production of Molybdenum-99

The medical isotope Molybdenum-99 is presently used for 80-85% of all nuclear medicine procedures and is produced by irradiating highly enriched uranium U-235 targets in NRU reactors. It was recently proposed that an electron linac be used for the production of 99Mo via photo-fission of a natural uranium target coming from the excitation of the giant dipole resonance around 15 MeV. The photons can be produced using the braking radiation (“bremsstrahlung”) spectrum of an electron beam impinged on a high Z material. In this paper we present an alternate concept for the production of 99Mo which is also based on photo-fission of U-238, but where the ~15 MeV gamma-rays are produced by Compton backscattering of laser photons from relativistic electrons. We assume a laser wavelength of 330 nm, resulting in 485 MeV electron beam energy, and 10 mA of average current. Because the induced energy spread on the electron beam is a few percent, one may recover most of the electron beam energy, which substantially increases the efficiency of the system. The accelerator concept, based on a three-pass recirculation system with energy recovery, is described and efficiency estimates are presented.
Date: May 1, 2009
Creator: L. Merminga, G.A. Krafft
Object Type: Article
System: The UNT Digital Library
Connecticut Transit (CTTRANSIT) Fuel Cell Transit Bus: Second Evaluation Report and Appendices (open access)

Connecticut Transit (CTTRANSIT) Fuel Cell Transit Bus: Second Evaluation Report and Appendices

This report describes operations at Connecticut Transit (CTTRANSIT) in Hartford for one prototype fuel cell bus and three new diesel buses operating from the same location. The evaluation period in this report (January 2008 through February 2009) has been chosen to coincide with a UTC Power propulsion system changeout that occurred on January 15, 2008.
Date: May 1, 2009
Creator: Chandler, K. & Eudy, L.
Object Type: Report
System: The UNT Digital Library
Control System Design for Automatic Cavity Tuning Machines (open access)

Control System Design for Automatic Cavity Tuning Machines

A series of four automatic tuning machines for 9-cell TESLA-type cavities are being developed and fabricated in a collaborative effort among DESY, FNAL, and KEK. These machines are intended to support high-throughput cavity fabrication for construction of large SRF-based accelerator projects. Two of these machines will be delivered to cavity vendors for the tuning of XFEL cavities. The control system for these machines must support a high level of automation adequate for industrial use by non-experts operators. This paper describes the control system hardware and software design for these machines.
Date: May 1, 2009
Creator: Carcagno, R.; Khabiboulline, T.; Kotelnikov, S.; Makulski, A.; Nehring, R.; Nogiec, J. et al.
Object Type: Article
System: The UNT Digital Library
Cooperative Extension Service & Wind Powering America Collaborate to Provide Wind Energy Information to Rural Stakeholders (Poster) (open access)

Cooperative Extension Service & Wind Powering America Collaborate to Provide Wind Energy Information to Rural Stakeholders (Poster)

Cooperative Extension's presence blankets much of the United States and has been a trusted information source to rural Americans. By working together, Cooperative Extension, Wind Powering America, and the wind industry can better educate the public and rural stakeholders about wind energy and maximize the benefits of wind energy to local communities. This poster provides an overview of Cooperative Extension, wind energy issues addressed by the organization, and related activities.
Date: May 1, 2009
Creator: Jimenez, A.; Flower, L. & Hamlen, S.
Object Type: Article
System: The UNT Digital Library
Corrective Action Decision Document/Closure Report for Corrective Action Unit 370: T-4 Atmospheric Test Site, Nevada Test Site, Nevada, Revision 0 (open access)

Corrective Action Decision Document/Closure Report for Corrective Action Unit 370: T-4 Atmospheric Test Site, Nevada Test Site, Nevada, Revision 0

This Corrective Action Decision Document/Closure Report has been prepared for Corrective Action Unit (CAU) 370, T-4 Atmospheric Test Site, located in Area 4 at the Nevada Test Site, Nevada, in accordance with the Federal Facility Agreement and Consent Order (FFACO). Corrective Action Unit 370 is comprised of Corrective Action Site (CAS) 04-23-01, Atmospheric Test Site T-4. The purpose of this Corrective Action Decision Document/Closure Report is to provide justification and documentation supporting the recommendation that no further corrective action is needed for CAU 370 due to the implementation of the corrective action of closure in place with administrative controls. To achieve this, corrective action investigation (CAI) activities were performed from June 25, 2008, through April 2, 2009, as set forth in the Corrective Action Investigation Plan for Corrective Action Unit 370: T-4 Atmospheric Test Site and Record of Technical Change No. 1.
Date: May 1, 2009
Creator: Matthews, Patrick
Object Type: Report
System: The UNT Digital Library
Corrective Action Decision Document/Closure Report for Corrective Action Unit 557: Spills and Tank Sites, Nevada Test Site, Nevada, Revision 0 (open access)

Corrective Action Decision Document/Closure Report for Corrective Action Unit 557: Spills and Tank Sites, Nevada Test Site, Nevada, Revision 0

This Corrective Action Decision Document/Closure Report has been prepared for Corrective Action Unit (CAU) 557, Spills and Tank Sites, in Areas 1, 3, 6, and 25 of the Nevada Test Site, Nevada, in accordance with the Federal Facility Agreement and Consent Order. Corrective Action Unit 557 comprises the following corrective action sites (CASs): • 01-25-02, Fuel Spill • 03-02-02, Area 3 Subdock UST • 06-99-10, Tar Spills • 25-25-18, Train Maintenance Bldg 3901 Spill Site The purpose of this Corrective Action Decision Document/Closure Report is to identify and provide the justification and documentation that supports the recommendation for closure of the CAU 557 CASs with no further corrective action. To achieve this, a corrective action investigation (CAI) was conducted from May 5 through November 24, 2008. The CAI activities were performed as set forth in the Corrective Action Investigation Plan for Corrective Action Unit 557: Spills and Tank Sites, Nevada Test Site, Nevada.
Date: May 1, 2009
Creator: Wickline, Alfred
Object Type: Report
System: The UNT Digital Library
Correlating Dynamometer Testing to In-Use Fleet Results of Plug-In Hybrid Electric Vehicles (open access)

Correlating Dynamometer Testing to In-Use Fleet Results of Plug-In Hybrid Electric Vehicles

Standard dynamometer test procedures are currently being developed to determine fuel and electrical energy consumption of plug-in hybrid vehicles (PHEV). To define a repeatable test procedure, assumptions were made about how PHEVs will be driven and charged. This study evaluates these assumptions by comparing results of PHEV dynamometer testing following proposed procedures to actual performance of PHEVs operating in the US Department of Energy’s (DOE) North American PHEV Demonstration fleet. Results show PHEVs in the fleet exhibit a wide range of energy consumption, which is not demonstrated in dynamometer testing. Sources of variation in performance are identified and examined.
Date: May 1, 2009
Creator: Smart, John G.; White, Sera & Duoba, Michael
Object Type: Article
System: The UNT Digital Library
Covenant Deferral Request for the Proposed Transfer of Land Parcel ED-8 at the East Tennessee Technology Park, Oak Ridge, Tennessee - Final - May 2009 (open access)

Covenant Deferral Request for the Proposed Transfer of Land Parcel ED-8 at the East Tennessee Technology Park, Oak Ridge, Tennessee - Final - May 2009

The United States Department of Energy (DOE) is proposing to transfer a land parcel (hereinafter referred to as 'the Property') designated as Land Parcel ED-8 at the East Tennessee Technology Park (ETTP) in Oak Ridge, Tennessee, by deed, and is submitting this Covenant Deferral Request (CDR) pursuant to Section 120(h)(3)(C) of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended, and applicable U. S. Environmental Protection Agency (EPA) guidance. The Oak Ridge Reservation (ORR), which includes ETTP, was placed on the National Priorities List (NPL) in November 1989. Environmental investigation and cleanup activities are continuing at ETTP in accordance with CERCLA, the National Contingency Plan (NCP), and the Federal Facility Agreement (FFA). The FFA was entered into by the DOE-Oak Ridge Office (ORO), EPA Region 4, and the Tennessee Department of Environment and Conservation (TDEC) in 1991. The FFA establishes the schedule and milestones for environmental remediation of the ORR. The proposed property transfer is a key component of the Oak Ridge Performance Management Plan (ORPMP) for accelerated cleanup of the ORR. DOE, using its authority under Section 161(g) of the Atomic Energy Act of 1954 (AEA), proposes to transfer the Property to Heritage Center, LLC, a subsidiary …
Date: May 1, 2009
Creator: SAIC
Object Type: Report
System: The UNT Digital Library
Critical Causes of Degradation in Integrated Laboratory Scale Cells during High Temperature Electrolysis (open access)

Critical Causes of Degradation in Integrated Laboratory Scale Cells during High Temperature Electrolysis

An ongoing project at Idaho National Laboratory involves generating hydrogen from steam using solid oxide electrolysis cells (SOEC). This report describes background information about SOECs, the Integrated Laboratory Scale (ILS) testing of solid-oxide electrolysis stacks, ILS performance degradation, and post-test examination of SOECs by various researchers. The ILS test was a 720- cell, three-module test comprised of 12 stacks of 60 cells each. A peak H2 production rate of 5.7 Nm3/hr was achieved. Initially, the module area-specific resistance ranged from 1.25 Ocm2 to just over 2 Ocm2. Total H2 production rate decreased from 5.7 Nm3/hr to a steady state value of 0.7 Nm3/hr. The decrease was primarily due to cell degradation. Post test examination by Ceramatec showed that the hydrogen electrode appeared to be in good condition. The oxygen evolution electrode does show delamination in operation and an apparent foreign layer deposited at the electrolyte interface. Post test examination by Argonne National Laboratory showed that the O2-electrode delaminated from the electrolyte near the edge. One possible reason for this delamination is excessive pressure buildup with high O2 flow in the over-sintered region. According to post test examination at the Massachusetts Institute of Technology, the electrochemical reactions have been recognized as …
Date: May 1, 2009
Creator: Sohal, M. S.; O'Brien, J. E.; Stoots, C. M.; Hartvigsen, J. J.; Larsen, D.; Elangovan, S. et al.
Object Type: Report
System: The UNT Digital Library
Critical Infrastructure Modeling: An Approach to Characterizing Interdependencies of Complex Networks & Control Systems (open access)

Critical Infrastructure Modeling: An Approach to Characterizing Interdependencies of Complex Networks & Control Systems

Critical infrastructure control systems face many challenges entering the 21st century, including natural disasters, cyber attacks, and terrorist attacks. Revolutionary change is required to solve many existing issues, including gaining greater situational awareness and resiliency through embedding modeling and advanced control algorithms in smart sensors and control devices instead of in a central controller. To support design, testing, and component analysis, a flexible simulation and modeling capability is needed. Researchers at Idaho National Laboratory are developing and evaluating such a capability through their CIPRsim modeling and simulation framework.
Date: May 1, 2009
Creator: Walsh, Stuart; Cherry, Shane & Roybal, Lyle
Object Type: Article
System: The UNT Digital Library
Cryogenic Test of a Coaxial Coupling Scheme for Fundamental and Higher Order Modes in Superconducting Cavities (open access)

Cryogenic Test of a Coaxial Coupling Scheme for Fundamental and Higher Order Modes in Superconducting Cavities

A coaxial coupling device located in the beam pipe of the TESLA type superconducting cavities provides for better propagation of Higher Order Modes (HOMs) and their strong damping in appropriate HOM couplers. Additionally, it also provides efficient coupling for fundamental mode RF power into the superconducting cavity. The whole coupling device can be designed as a detachable system. If appropriately dimensioned, the magnetic field can be minimized to a negligible level at the flange position. This scheme, presented previously*, provides for several advantages: strong HOM damping, flangeable solution, exchangeability of the HOM damping device on a cavity, less complexity of the superconducting cavity, possible cost advantages. This contribution will describe the results of the first cryogenic test.
Date: May 1, 2009
Creator: J.K. Sekutowicz, P. Kneisel
Object Type: Article
System: The UNT Digital Library
Cryogenic Test of the Nb-Pb SRF Photoinjector Cavities (open access)

Cryogenic Test of the Nb-Pb SRF Photoinjector Cavities

In this contribution, we report progress on the development of a hybrid lead/niobium superconducting RF (SRF) photoinjector. The goal of this effort is to build a Nb injector with the superconducting cathode made of lead, which demonstrated in the past superior quantum efficiency (QE) compared to Nb Three prototype hybrid devices, consisting of an all-niobium cavity with an arc-deposited spot of lead in the cathode region, have been constructed and tested. We present the cold test results of these cavities with and without lead.
Date: May 1, 2009
Creator: Sekutowicz, J. K.; Muhs, A.; Kneisel, P. & Nietubyc, R.
Object Type: Article
System: The UNT Digital Library
CSR Interaction for a 2D Energy-Chirped Bunch on a General Orbit (open access)

CSR Interaction for a 2D Energy-Chirped Bunch on a General Orbit

When an electron bunch with initial linear energy chirp traverses a bunch compression chicane, the bunch interacts with itself via coherent synchrotron radiation (CSR) and space charge force. The effective longitudinal CSR force for such kind of 2D bunch on a circular orbit has been analyzed earlier [1]. In this paper, we present the analytical results of the effective longitudinal CSR force for a 2D energy-chirped bunch going through a general orbit, which includes the entrance and exit of a circular orbit. In particular, we will show the behavior of the force in the last bend of a chicane when the bunch is under extreme compression. This is the condition when bifurcation of bunch phase space occurs in many CSR measurements. [1] R. Li, Phys. Rev. ST Accel. Beams 11, 024401 (2008)
Date: May 1, 2009
Creator: Li, Rui
Object Type: Article
System: The UNT Digital Library