Novel Geometries for the LHC Crab Cavity (open access)

Novel Geometries for the LHC Crab Cavity

The planned luminosity upgrade to LHC is likely to necessitate a large crossing angle and a local crab crossing scheme. For this scheme crab cavities align bunches prior to collision. The scheme requires at least four such cavities, a pair on each beam line either side of the interaction point (IP). Upstream cavities initiate rotation and downstream cavities cancel rotation. Cancellation is usually done at a location where the optics has re-aligned the bunch. The beam line separation near the IP necessitates a more compact design than is possible with elliptical cavities such as those used at KEK. The reduction in size must be achieved without an increase in the operational frequency to maintain compatibility with the long bunch length of the LHC. This paper proposes a suitable superconducting variant of a four rod coaxial deflecting cavity (to be phased as a crab cavity), and presents analytical models and simulations of suitable designs.
Date: May 1, 2010
Creator: B. Hall,G. Burt,C. Lingwood,Robert Rimmer,Haipeng Wang; Hall, B.; Burt, G.; Lingwood, C.; Rimmer, Robert & Wang, Haipeng
Object Type: Article
System: The UNT Digital Library
Development of a Polar Drive Shock Ignition Platform on the National Ignition Facility (open access)

Development of a Polar Drive Shock Ignition Platform on the National Ignition Facility

None
Date: May 13, 2010
Creator: Perkins, L. J.; Schurtz, G. P.; Betti, R.; Craxton, R. S.; LaFortune, K. N.; Casner, A. et al.
Object Type: Report
System: The UNT Digital Library
The Status of De-Inventory of Security Category I/II Nuclear Materials at Lawrence Livermore National Laboratory (LLNL) (open access)

The Status of De-Inventory of Security Category I/II Nuclear Materials at Lawrence Livermore National Laboratory (LLNL)

None
Date: May 13, 2010
Creator: Riley, D C & Dodson, K
Object Type: Article
System: The UNT Digital Library
Electron Cloud at Low Emittance in CesrTA (open access)

Electron Cloud at Low Emittance in CesrTA

The Cornell Electron Storage Ring (CESR) has been reconfigured as a test accelerator (CesrTA) for a program of electron cloud (EC) research at ultra low emittance. The instrumentation in the ring has been upgraded with local diagnostics for measurement of cloud density and with improved beam diagnostics for the characterization of both the low emittance performance and the beam dynamics of high intensity bunch trains interacting with the cloud. A range of EC mitigation methods have been deployed and tested and their effectiveness is discussed. Measurements of the electron cloud's effect on the beam under a range of conditions are discussed along with the simulations being used to quantitatively understand these results.
Date: May 23, 2010
Creator: Alexander, J. P.; Billing, M. G.; Calvey, J.; Crittenden, J. A.; Dugan, G.; Eggert, N. et al.
Object Type: Article
System: The UNT Digital Library
Daemen Alternative Energy/Geothermal Technologies Demonstration Program Erie County (open access)

Daemen Alternative Energy/Geothermal Technologies Demonstration Program Erie County

The purpose of the Daemen Alternative Energy/Geothermal Technologies Demonstration Project is to demonstrate the use of geothermal technology as model for energy and environmental efficiency in heating and cooling older, highly inefficient buildings. The former Marian Library building at Daemen College is a 19,000 square foot building located in the center of campus. Through this project, the building was equipped with geothermal technology and results were disseminated. Gold LEED certification for the building was awarded. 1) How the research adds to the understanding of the area investigated. This project is primarily a demonstration project. Information about the installation is available to other companies, organizations, and higher education institutions that may be interested in using geothermal energy for heating and cooling older buildings. 2) The technical effectiveness and economic feasibility of the methods or techniques investigated or demonstrated. According to the modeling and estimates through Stantec, the energy-efficiency cost savings is estimated at 20%, or $24,000 per year. Over 20 years this represents $480,000 in unrestricted revenue available for College operations. See attached technical assistance report. 3) How the project is otherwise of benefit to the public. The Daemen College Geothermal Technologies Ground Source Heat Pumps project sets a standard for …
Date: May 20, 2010
Creator: Robert C. Beiswanger, Jr.
Object Type: Article
System: The UNT Digital Library
Development of a Fiber Laser Welding Capability for the W76, MC4702 Firing Set (open access)

Development of a Fiber Laser Welding Capability for the W76, MC4702 Firing Set

Development work to implement a new welding system for a Firing Set is presented. The new system is significant because it represents the first use of fiber laser welding technology at the KCP. The work used Six-Sigma tools for weld characterization and to define process performance. Determinations of workable weld parameters and comparison to existing equipment were completed. Replication of existing waveforms was done utilizing an Arbitrary Pulse Generator (APG), which was used to modulate the fiber laser’s exclusive continuous wave (CW) output. Fiber laser weld process capability for a Firing Set is demonstrated.
Date: May 12, 2010
Creator: Samayoa, Jose
Object Type: Report
System: The UNT Digital Library
Characterization of the role of Fhit in maintenance of genomic integrity following low dose radiation, in vivo and in vitro (open access)

Characterization of the role of Fhit in maintenance of genomic integrity following low dose radiation, in vivo and in vitro

The major goal of this study is to determine the effects of the Fhit pathway on low dose (< 0.1 Gy) ionizing radiation (IR)-induced genetic instability. Reduction of Fhit protein expression is observed in most solid tumors particularly in those tumors resulting from exposure to environmental carcinogens. Therefore, characterization of the role of the Fhit-dependent pathway in preventing low dose IR-induced genetic instability will provide useful parameters for evaluating the low dose IR-induced risk of mutagenesis and carcinogenesis. We pursued 3 specific aims to study our hypothesis that the Fhit-dependent pathways maintain genomic integrity through adjusting checkpoint response and repair genes expression following low dose IR. Aim 1: Determine whether Fhit interaction with RPA is necessary for Fhit to affect the cellular response to low dose IR. We combined the approaches of in vitro (GST pull-down and site-directed mutagenesis) and in vivo (observing the co-localization and immunoprecipitation of Fhit and RPA in Fhit knock out mouse cells transfected with mutant Fhit which has lost ability to interact with RPA in vitro). Aim 2: Determine the role of genes whose expression is affected by Fhit in low dose irradiated cells. We analyzed the distinct signature of gene expression in low dose …
Date: May 14, 2010
Creator: Wang, Ya
Object Type: Report
System: The UNT Digital Library
Preliminary Evaluation of the Section 1603 Treasury Grant Program for Renewable Power Projects in the United States (open access)

Preliminary Evaluation of the Section 1603 Treasury Grant Program for Renewable Power Projects in the United States

This article evaluates the first year of the Section 1603 Treasury cash grant program, which enables renewable power projects in the U.S. to elect cash grants in lieu of the federal tax credits that are otherwise available. To date, the program has been heavily subscribed, particularly by wind power projects, which had received 86% of the nearly $2.6 billion in grants that had been disbursed as of March 1, 2010. As of that date, 6.2 GW of the 10 GW of new wind capacity installed in the U.S. in 2009 had applied for grants in lieu of production tax credits. Roughly 2.4 GW of this wind capacity may not have otherwise been built in 2009 absent the grant program; this 2.4 GW may have supported approximately 51,600 short-term full-time-equivalent (FTE) gross job-years in the U.S. during the construction phase of these wind projects, and 3,860 longterm FTE gross jobs during the operational phase. The program’s popularity stems from the significant economic value that it provides to renewable power projects, relative to the otherwise available tax credits. Although grants reward investment rather than efficient performance, this evaluation finds no evidence at this time of either widespread “gold-plating” or performance problems.
Date: May 5, 2010
Creator: Bolinger, Mark; Wiser, Ryan & Darghouth, Naim
Object Type: Article
System: The UNT Digital Library
TOWARD HIGHLY SECURE AND AUTONOMIC COMPUTING SYSTEMS: A HIERARCHICAL APPROACH (open access)

TOWARD HIGHLY SECURE AND AUTONOMIC COMPUTING SYSTEMS: A HIERARCHICAL APPROACH

The overall objective of this research project is to develop novel architectural techniques as well as system software to achieve a highly secure and intrusion-tolerant computing system. Such system will be autonomous, self-adapting, introspective, with self-healing capability under the circumstances of improper operations, abnormal workloads, and malicious attacks. The scope of this research includes: (1) System-wide, unified introspection techniques for autonomic systems, (2) Secure information-flow microarchitecture, (3) Memory-centric security architecture, (4) Authentication control and its implication to security, (5) Digital right management, (5) Microarchitectural denial-of-service attacks on shared resources. During the period of the project, we developed several architectural techniques and system software for achieving a robust, secure, and reliable computing system toward our goal.
Date: May 11, 2010
Creator: Lee, Hsien-Hsin S
Object Type: Report
System: The UNT Digital Library
Infrared birefringence imaging of residual stress and bulk defects in multicrystalline silicon (open access)

Infrared birefringence imaging of residual stress and bulk defects in multicrystalline silicon

This manuscript concerns the application of infrared birefringence imaging (IBI) to quantify macroscopic and microscopic internal stresses in multicrystalline silicon (mc-Si) solar cell materials. We review progress to date, and advance four closely related topics. (1) We present a method to decouple macroscopic thermally-induced residual stresses and microscopic bulk defect related stresses. In contrast to previous reports, thermally-induced residual stresses in wafer-sized samples are generally found to be less than 5 MPa, while defect-related stresses can be several times larger. (2) We describe the unique IR birefringence signatures, including stress magnitudes and directions, of common microdefects in mc-Si solar cell materials including: {beta}-SiC and {beta}-Si{sub 3}N{sub 4} microdefects, twin bands, nontwin grain boundaries, and dislocation bands. In certain defects, local stresses up to 40 MPa can be present. (3) We relate observed stresses to other topics of interest in solar cell manufacturing, including transition metal precipitation, wafer mechanical strength, and minority carrier lifetime. (4) We discuss the potential of IBI as a quality-control technique in industrial solar cell manufacturing.
Date: May 5, 2010
Creator: Ganapati, Vidya; Schoenfelder, Stephan; Castellanos, Sergio; Oener, Sebastian; Koepge, Ringo; Sampson, Aaron et al.
Object Type: Article
System: The UNT Digital Library
Final Technical Report (open access)

Final Technical Report

Calabazas Creek Research Inc. (CCR) completed Phase I the development of a 10 MW, 1.3 GHz, annular beam klystron (ABK) for driving advanced accelerators, such as the International Linear Collider (ILC). Through detailed simulations in Phase I, CCR produced a design that meets all of the requirements for ILC. The ABK uses an annular beam to minimize space charge depression and the impedance. This allows the relatively low voltage of 120 kV specified for the International Linear Collider (ILC). Like the sheet beam klystron, the ABK uses a thin beam located close to the drift tube walls; however, it operates with lower risk, single mode cavities. In addition, it is azimuthally symmetric, dramatically reducing design and fabrication costs. It provides the same operating characteristics as a multi-beam klystron, but is far simpler and will be easier and less expensive to fabricate.
Date: May 17, 2010
Creator: Read, Michael; Ives, R. Lawrence & Ferguson, Patrick
Object Type: Report
System: The UNT Digital Library
An Online Scheduling Algorithm with Advance Reservation for Large-Scale Data Transfers (open access)

An Online Scheduling Algorithm with Advance Reservation for Large-Scale Data Transfers

Scientific applications and experimental facilities generate massive data sets that need to be transferred to remote collaborating sites for sharing, processing, and long term storage. In order to support increasingly data-intensive science, next generation research networks have been deployed to provide high-speed on-demand data access between collaborating institutions. In this paper, we present a practical model for online data scheduling in which data movement operations are scheduled in advance for end-to-end high performance transfers. In our model, data scheduler interacts with reservation managers and data transfer nodes in order to reserve available bandwidth to guarantee completion of jobs that are accepted and confirmed to satisfy preferred time constraint given by the user. Our methodology improves current systems by allowing researchers and higher level meta-schedulers to use data placement as a service where theycan plan ahead and reserve the scheduler time in advance for their data movement operations. We have implemented our algorithm and examined possible techniques for incorporation into current reservation frameworks. Performance measurements confirm that the proposed algorithm is efficient and scalable.
Date: May 20, 2010
Creator: Balman, Mehmet & Kosar, Tevfik
Object Type: Report
System: The UNT Digital Library
Long Range Active Detection of HEU Based on Thermal Neutron Multiplication (open access)

Long Range Active Detection of HEU Based on Thermal Neutron Multiplication

We report on the results of measurements of proton irradiation on a series of targets at Brookhaven National Laboratory’s (BNL) Alternate Gradient Synchrotron Facility (AGS), in collaboration with LANL and SNL. We examined the prompt radiation environment in the tunnel for the DTRA-sponsored series (E 972), which investigated the penetration of air and subsequent target interaction of 4 GeV proton pulses. Measurements were made by means of an organic scintillator with a 500 MHz bandwidth system. We found that irradiation of a depleted uranium (DU) target resulted in a large gamma-ray signal in the 100-500 µsec time region after the proton flash when the DU was surrounded by polyethylene, but little signal was generated if it was surrounded by boron-loaded polyethylene. Subsequent Monte Carlo (MCNPX) calculations indicated that the source of the signal was consistent with thermal neutron capture in DU. The MCNPX calculations also indicated that if one were to perform the same experiment with a highly enriched uranium (HEU) target there would be a distinctive fast neutron yield in this 100-500 µsec time region from thermal neutron-induced fission. The fast neutrons can be recorded by the same direct current system and differentiated from gamma ray pulses in organic …
Date: May 24, 2010
Creator: L., Forman; I., Dioszegi; Salwen, C. & and Vanier, P.E.
Object Type: Article
System: The UNT Digital Library
Immersed Boundary Methods for High-Resolution Simulation of Atmospheric Boundary-Layer Flow Over Complex Terrain (open access)

Immersed Boundary Methods for High-Resolution Simulation of Atmospheric Boundary-Layer Flow Over Complex Terrain

None
Date: May 12, 2010
Creator: Lundquist, K A
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Lithium-Air Battery (open access)

Lithium-Air Battery

Advanced Research Projects Agency-Energy project sheet summarizing general information about the Batteries for Electrical Energy Storage in Transportation (BEEST) program including critical needs, innovation and advantages, impacts, and contact information. This sheet discusses a new lithium-air battery for electric vehicles as part of the "High Performance Cathodes for Lithium-Air Batteries" project.
Date: May 10, 2010
Creator: Missouri University of Science and Technology
Object Type: Text
System: The UNT Digital Library
Proceedings of RIKEN BNL Research Center Workshop: Saturation, the Color Glass Condensate and the Glasma: What Have We Learned from RHIC? (open access)

Proceedings of RIKEN BNL Research Center Workshop: Saturation, the Color Glass Condensate and the Glasma: What Have We Learned from RHIC?

N/A
Date: May 10, 2010
Creator: J., Dunlop; McLerran, L.; Morrison, D. & Venugopalan, R.
Object Type: Report
System: The UNT Digital Library
Regulation of Nuclear Localization of Signaling Proteins by Cytokinin (open access)

Regulation of Nuclear Localization of Signaling Proteins by Cytokinin

Cytokinins are a class of mitogenic plant hormones that play an important role in most aspects of plant development, including shoot and root growth, vascular and photomorphogenic development and leaf senescence. A model for cytokinin perception and signaling has emerged that is similar to bacterial two-component phosphorelays. In this model, binding of cytokinin to the extracellular domain of the Arabidopsis histidine kinase (AHKs) receptors induces autophosphorylation within the intracellular histidine-kinase domain. The phosphoryl group is subsequently transferred to cytosolic Arabidopsis histidine phosphotransfer proteins (AHPs), which have been suggested to translocate to the nucleus in response to cytokinin treatment, where they then transfer the phosphoryl group to nuclear-localized response regulators (Type-A and Type-B ARRs). We examined the effects of cytokinin on AHP subcellular localization in Arabidopsis and, contrary to expectations, the AHPs maintained a constant nuclear/cytosolic distribution following cytokinin treatment. Furthermore, mutation of the conserved phosphoacceptor histidine residue of the AHP, as well as disruption of multiple cytokinin signaling elements, did not affect the subcellular localization of the AHP proteins. Finally, we present data indicating that AHPs maintain a nuclear/cytosolic distribution by balancing active transport into and out of the nucleus. Our findings suggest that the current models indicating relocalization of …
Date: May 1, 2010
Creator: Kieber, J. J.
Object Type: Report
System: The UNT Digital Library
Xyce parallel electronic simulator. (open access)

Xyce parallel electronic simulator.

This document is a reference guide to the Xyce Parallel Electronic Simulator, and is a companion document to the Xyce Users' Guide. The focus of this document is (to the extent possible) exhaustively list device parameters, solver options, parser options, and other usage details of Xyce. This document is not intended to be a tutorial. Users who are new to circuit simulation are better served by the Xyce Users' Guide.
Date: May 1, 2010
Creator: Keiter, E. R.; Mei, Ting; Russo, T. V.; Rankin, E. L.; Schiek, R. L.; Thornquist, H. K. et al.
Object Type: Report
System: The UNT Digital Library
Xyce parallel electronic simulator release notes. (open access)

Xyce parallel electronic simulator release notes.

The Xyce Parallel Electronic Simulator has been written to support, in a rigorous manner, the simulation needs of the Sandia National Laboratories electrical designers. Specific requirements include, among others, the ability to solve extremely large circuit problems by supporting large-scale parallel computing platforms, improved numerical performance and object-oriented code design and implementation. The Xyce release notes describe: Hardware and software requirements New features and enhancements Any defects fixed since the last release Current known defects and defect workarounds For up-to-date information not available at the time these notes were produced, please visit the Xyce web page at http://www.cs.sandia.gov/xyce.
Date: May 1, 2010
Creator: Keiter, Eric R.; Hoekstra, Robert J.; Mei, Ting; Russo, Thomas V.; Schiek, Richard L.; Thornquist, Heidi K. et al.
Object Type: Report
System: The UNT Digital Library
New Particle-in-Cell Code for Numerical Simulation of Coherent Synchrotron Radiation (open access)

New Particle-in-Cell Code for Numerical Simulation of Coherent Synchrotron Radiation

We present a first look at the new code for self-consistent, 2D simulations of beam dynamics affected by the coherent synchrotron radiation. The code is of the particle-in-cell variety: the beam bunch is sampled by point-charge particles, which are deposited on the grid; the corresponding forces on the grid are then computed using retarded potentials according to causality, and interpolated so as to advance the particles in time. The retarded potentials are evaluated by integrating over the 2D path history of the bunch, with the charge and current density at the retarded time obtained from interpolation of the particle distributions recorded at discrete timesteps. The code is benchmarked against analytical results obtained for a rigid-line bunch. We also outline the features and applications which are currently being developed.
Date: May 1, 2010
Creator: Balsa Terzic, Rui Li
Object Type: Article
System: The UNT Digital Library
BEAM CONTAINMENT SYSTEM FOR NSLS-II (open access)

BEAM CONTAINMENT SYSTEM FOR NSLS-II

The shielding design for the NSLS-II will provide adequate protection for the full injected beam loss in two periods of the ring around the injection point, but the remainder of the ring is shielded for lower losses of {le} 10% full beam. This will require a system to insure that beam losses don't exceed these levels for a period of time that could cause excessive radiation levels outside the shield walls. This beam containment system will measure, provide a level of control and alarm indication of the beam power losses along the beam path from the source (e-gun, linac) thru the injection system and the storage ring. This system will consist of collimators that will provide limits to (and potentially to measure) the beam miss-steering and control the loss points of the charge and monitors that will measure the average beam current losses along the beam path and alarm when this beam power loss exceeds the level set by the shielding specifications. This will require some new ideas in beam loss detection capability and collimation. The initial planning and R&amp;D program will be presented.
Date: May 23, 2010
Creator: Kramer, S. L.; Casey, W. & Job, P. K.
Object Type: Article
System: The UNT Digital Library
Novel Geometries for the LHC Crab Cavity (open access)

Novel Geometries for the LHC Crab Cavity

The planned luminosity upgrade to LHC is likely to necessitate a large crossing angle and a local crab crossing scheme. For this scheme crab cavities align bunches prior to collision. The scheme requires at least four such cavities, a pair on each beam line either side of the interaction point (IP). Upstream cavities initiate rotation and downstream cavities cancel rotation. Cancellation is usually done at a location where the optics has re-aligned the bunch. The beam line separation near the IP necessitates a more compact design than is possible with elliptical cavities such as those used at KEK. The reduction in size must be achieved without an increase in the operational frequency to maintain compatibility with the long bunch length of the LHC. This paper proposes a suitable superconducting variant of a four rod coaxial deflecting cavity (to be phased as a crab cavity), and presents analytical models and simulations of suitable designs.
Date: May 23, 2010
Creator: B. Hall, G. Burt, C. Lingwood, R. Rimmer, H. Wang
Object Type: Article
System: The UNT Digital Library
An imaging proton spectrometer for short-pulse laser plasma experiments (open access)

An imaging proton spectrometer for short-pulse laser plasma experiments

Ultra intense short pulse laser pulses incident on solid targets can generate energetic protons. In additions to their potentially important applications such as in cancer treatments and proton fast ignition, these protons are essential to understand the complex physics of intense laser plasma interaction. To better characterize these laser-produced protons, we designed and constructed a novel, spatially imaging proton spectrometer that will not only measure proton energy distribution with high resolution, but also provide its angular characteristics. The information obtained from this spectrometer compliments those from commonly used diagnostics including radiochromic film packs, CR39 nuclear track detectors, and non-imaging magnetic spectrometers. The basic characterizations and sample data from this instrument are presented.
Date: May 11, 2010
Creator: Chen, H.; Hazi, A.; van Maren, R.; Chen, S.; Fuchs, J.; Gauthier, M. et al.
Object Type: Article
System: The UNT Digital Library
RHIC BBLR measurements in 2009 (open access)

RHIC BBLR measurements in 2009

Long range beam-beam experiments were conducted during the Run 2009 in the Yellow and the Blue beams of the RHIC accelerator with DC wires. The effects of a long-range interaction with a DC wire on colliding and non-colliding bunches with the aid of beam losses, orbits, tunes were studied. Results from distance scans and an attempt to compensate a long-range interaction with a DC wire is presented. Two DC wires in the vertical plane were installed in the RHIC accelerator in 2006 with the aim of investigating long range (LR) beam-beam effects and a potential compensation. Extensive experiments were conducted focusing mainly on the effect of a wire on single ion beams from 2006-2009. A unique opportunity to compare the effect of the wire on colliding beams and compensation of a single LR beam-beam interaction were conducted in Run2009 with protons at 100 GeV. Due to aperture considerations for decreasing {beta}*, the Blue wire was removed during the shutdown after the Run2009 and the Yellow wire is foreseen to be removed in the near future. Therefore, these experiments serve as the final set of measurements for LR beam-beam with RHIC as a test bed. The relevant RHIC beam and lattice …
Date: May 23, 2010
Creator: Calaga, R.; Robert-Demolaize, G. & Fischer, W.
Object Type: Article
System: The UNT Digital Library