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Collective Effects in the SuperB Collider (open access)

Collective Effects in the SuperB Collider

Some collective effects have been studied for the SuperB high luminosity collider. Estimates of the effect of Intra Beam Scattering (IBS) on the emittance and energy spread growths have been carried up for both the High Energy (HER, positrons) and the Low Energy (LER, electrons) rings. Electron cloud build up simulations for HER were performed with the ECLOUD code, developed at CERN, to predict the cloud formation in the arcs, taking into account possible remediation techniques such as clearing electrodes. The new code CMAD, developed at SLAC, has been used to study the effect of this electron cloud on the beam and assess the thresholds above which the electron cloud instability would set in.
Date: June 25, 2012
Creator: Demma, Theo; /INFN, Rome & Pivi, Mauro
Object Type: Article
System: The UNT Digital Library
Design and Modeling of an Asynchronous Checkpointing System (open access)

Design and Modeling of an Asynchronous Checkpointing System

None
Date: June 25, 2012
Creator: Sato, K; Moody, A; Mohror, K; Gamblin, T; de Supinski, B; Maruyama, N et al.
Object Type: Article
System: The UNT Digital Library
End-To-End Solution for Integrated Workload and Data Management Using Glidein WMS and Globus Online (open access)

End-To-End Solution for Integrated Workload and Data Management Using Glidein WMS and Globus Online

None
Date: June 25, 2012
Creator: Mhashilkar, Parag; Garzoglio, Gabriele; Holzman, Burt; Duan, Xi; /Fermilab; Miller, Zachary et al.
Object Type: Article
System: The UNT Digital Library
The FDA Medical Device User Fee Program (open access)

The FDA Medical Device User Fee Program

None
Date: June 25, 2012
Creator: Johnson, Judith A.
Object Type: Report
System: The UNT Digital Library
FDA Regulation of Medical Devices (open access)

FDA Regulation of Medical Devices

This report provides a description of FDA's medical device review process divided into two parts: pre market requirements and post market requirements. Appendix A provides a brief history of laws governing medical device regulation and Appendix B provides a table of acronyms used in the report.
Date: June 25, 2012
Creator: Johnson, Judith A.
Object Type: Report
System: The UNT Digital Library
FDA’s Authority to Ensure That Drugs Prescribed to Children Are Safe and Effective (open access)

FDA’s Authority to Ensure That Drugs Prescribed to Children Are Safe and Effective

The report describes why research on a drug's pharmacokinetics, safety, and effectiveness in children might be necessary. This report then presents why the marketplace has not provided sufficient incentives to manufacturers of drugs approved for adult use to study their effects in children. It also analyzes the impact of BPCA and PREA have had on pediatric drug research.
Date: June 25, 2012
Creator: Thaul, Susan
Object Type: Report
System: The UNT Digital Library
Field Tolerances for the Triplet Quadrupoles of the LHC High Luminosity Lattice (open access)

Field Tolerances for the Triplet Quadrupoles of the LHC High Luminosity Lattice

It has been proposed to implement the so-called Achromatic Telescopic Squeezing (ATS) scheme in the LHC high luminosity (HL) lattice to reduce beta functions at the Interaction Points (IP) up to a factor of 8. As a result, the nominal 4.5 km peak beta functions reached in the Inner Triplets (IT) at collision will be increased by the same factor. This, therefore, justifies the installation of new, larger aperture, superconducting IT quadrupoles. The higher beta functions will enhance the effects of the triplet quadrupole field errors leading to smaller beam dynamic aperture (DA). To maintain the acceptable DA, the effects of the triplet field errors must be re-evaluated, thus specifying new tolerances. Such a study has been performed for the so-called '4444' collision option of the HL-LHC layout version SLHCV3.01, where the IP beta functions are reduced by a factor of 4 in both planes with respect to a pre-squeezed value of 60 cm at two collision points. The dynamic aperture calculations were performed using SixTrack. The impact on the triplet field quality is presented.
Date: June 25, 2012
Creator: Nosochkov, Yuri; Cai, Y.; Jiao, Y.; Wang, M. H.; Fartoukh, S.; Giovannozzi, M. et al.
Object Type: Article
System: The UNT Digital Library
Haiti Under President Martelly: Current Conditions and Congressional Concerns (open access)

Haiti Under President Martelly: Current Conditions and Congressional Concerns

This report gives an overview of the current government in Haiti and status of recovery efforts following the 2010 earthquake. The Haitian government and the international donor community are implementing a 10-year recovery plan focusing on territorial, economic, social, and institutional rebuilding. The main priorities for U.S. policy regarding Haiti are to strengthen fragile democratic processes, continue to improve security, and promote economic development. Other concerns include the cost and effectiveness of U.S. aid; protecting human rights; combating narcotics, arms, and human trafficking; and alleviating poverty. Congressional concerns include the pace and effectiveness of reconstruction; respect for human rights, particularly for women; counternarcotics efforts; and security issues.
Date: June 25, 2012
Creator: Taft-Morales, Maureen
Object Type: Report
System: The UNT Digital Library
HOM identification by bead pulling in the Brookhaven ERL cavity (open access)

HOM identification by bead pulling in the Brookhaven ERL cavity

Several past measurements of the Brookhaven ERL at superconducting temperature produced a long list of higher order modes (HOMs). The Niobium 5-cell cavity is terminated with HOM ferrite dampers that successfully reduce the Q-factors to tolerable levels. However, a number of undamped resonances with Q {ge} 10{sup 6} were found at 4 K and their mode identification remained as a goal for this paper. The approach taken here consists in taking different S{sub 21} measurements on a copper cavity replica of the ERL which can be compared with the actual data and also with Microwave Studio computer simulations. Several different S{sub 21} transmission measurements are used, including those taken from the fundamental input coupler to the pick-up probe across the cavity, between probes in a single cell, and between beam-position monitor probes in the beam tubes. Mode identification is supported by bead pulling with a metallic needle or a dielectric sphere that are calibrated in the fundamental mode. This paper presents results for HOMs in the first two dipole bands with the prototypical 958 MHz trapped mode, the lowest beam tube resonances, and high-Q modes in the first quadrupole band and beyond.
Date: June 25, 2012
Creator: Hahn, H.; Calaga, R.; Jain, P.; Johnson, E. C. & Xu, W.
Object Type: Article
System: The UNT Digital Library
How FDA Approves Drugs and Regulates Their Safety and Effectiveness (open access)

How FDA Approves Drugs and Regulates Their Safety and Effectiveness

This report is a primer on drug approval and regulation: it describes how drugs are approved and come to the market, including FDA's role in that process and FDA and industry roles once drugs are on the pharmacy shelves.
Date: June 25, 2012
Creator: Thaul, Susan
Object Type: Report
System: The UNT Digital Library
Management Report: Improvements Are Needed to Enhance the Internal Revenue Service's Internal Controls and Operating Effectiveness (open access)

Management Report: Improvements Are Needed to Enhance the Internal Revenue Service's Internal Controls and Operating Effectiveness

Correspondence issued by the Government Accountability Office with an abstract that begins "During our audit of IRS’s fiscal year 2011 financial statements, we identified new internal control deficiencies in the following areas:"
Date: June 25, 2012
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library
Markov Model of Severe Accident Progression and Management (open access)

Markov Model of Severe Accident Progression and Management

The earthquake and tsunami that hit the nuclear power plants at the Fukushima Daiichi site in March 2011 led to extensive fuel damage, including possible fuel melting, slumping, and relocation at the affected reactors. A so-called feed-and-bleed mode of reactor cooling was initially established to remove decay heat. The plan was to eventually switch over to a recirculation cooling system. Failure of feed and bleed was a possibility during the interim period. Furthermore, even if recirculation was established, there was a possibility of its subsequent failure. Decay heat has to be sufficiently removed to prevent further core degradation. To understand the possible evolution of the accident conditions and to have a tool for potential future hypothetical evaluations of accidents at other nuclear facilities, a Markov model of the state of the reactors was constructed in the immediate aftermath of the accident and was executed under different assumptions of potential future challenges. This work was performed at the request of the U.S. Department of Energy to explore 'what-if' scenarios in the immediate aftermath of the accident. The work began in mid-March and continued until mid-May 2011. The analysis had the following goals: (1) To provide an overall framework for describing possible …
Date: June 25, 2012
Creator: Bari, R. A.; Cheng, L.; Cuadra, A.; Ginsberg, T.; Lehner, J.; Martinez-Guridi, G. et al.
Object Type: Article
System: The UNT Digital Library
Methyl Iodide Fumigation of Bacillus Anthracis Spores (open access)

Methyl Iodide Fumigation of Bacillus Anthracis Spores

None
Date: June 25, 2012
Creator: Sutton, M; Kane, S R & Wollard, J R
Object Type: Report
System: The UNT Digital Library
Optimisation of An HHG-Seeded Harmonic Cascade FEL Design for the NLS Project (open access)

Optimisation of An HHG-Seeded Harmonic Cascade FEL Design for the NLS Project

Optimization studies of an HHG-seeded harmonic cascade FEL design for the UK's proposed New Light Source (NLS) facility are presented. Three separate FELs are planned to meet the requirements for continuous coverage of the photon energy range 50-1000 eV with variable polarization, 20 fs pulse widths and good temporal coherence. The design uses an HHG seed source tuneable from 50-100 eV to provide direct FEL seeding in this range, and one or two stage harmonic cascades to reach the higher photon energies. Studies have been carried out to optimize a harmonic cascade FEL operating at 1 keV; topics investigated include modulator configuration, seed power level and ef- fects of the HHG seed structure. FEL simulations using realistic electron beam distributions are presented and tolerance to increased emittance has been considered.
Date: June 25, 2012
Creator: Dunning, David; Thompson, Neil; Bartolini, Riccardo; Geng, Huiping; Huang, Zhirong & McNeil, Brian
Object Type: Article
System: The UNT Digital Library
Overview of Mono-Energetic Gamma-Ray Sources and Applications (open access)

Overview of Mono-Energetic Gamma-Ray Sources and Applications

Recent progress in accelerator physics and laser technology have enabled the development of a new class of tunable gamma-ray light sources based on Compton scattering between a high-brightness, relativistic electron beam and a high intensity laser pulse produced via chirped-pulse amplification (CPA). A precision, tunable Mono-Energetic Gamma-ray (MEGa-ray) source driven by a compact, high-gradient X-band linac is currently under development and construction at LLNL. High-brightness, relativistic electron bunches produced by an X-band linac designed in collaboration with SLAC NAL will interact with a Joule-class, 10 ps, diode-pumped CPA laser pulse to generate tunable {gamma}-rays in the 0.5-2.5 MeV photon energy range via Compton scattering. This MEGaray source will be used to excite nuclear resonance fluorescence in various isotopes. Applications include homeland security, stockpile science and surveillance, nuclear fuel assay, and waste imaging and assay. The source design, key parameters, and current status are presented, along with important applications, including nuclear resonance fluorescence.
Date: June 25, 2012
Creator: Hartemann, Fred; /LLNL, Livermore; Albert, Felicie; /LLNL, Livermore; Anderson, Scott; /LLNL, Livermore et al.
Object Type: Article
System: The UNT Digital Library
Pension Benefit Guaranty Corporation (PBGC) and Defined Benefit Pension Plan Funding Issues (open access)

Pension Benefit Guaranty Corporation (PBGC) and Defined Benefit Pension Plan Funding Issues

None
Date: June 25, 2012
Creator: unknown
Object Type: Report
System: The UNT Digital Library
PHASE II VAULT TESTING OF THE ARGONNE RFID SYSTEM (open access)

PHASE II VAULT TESTING OF THE ARGONNE RFID SYSTEM

The U.S. Department of Energy (DOE) (Environmental Management [EM], Office of Packaging and Transportation [EM-45]) Packaging and Certification Program (DOE PCP) has developed a Radio Frequency Identification (RFID) tracking and monitoring system, called ARG-US, for the management of nuclear materials packages during transportation and storage. The performance of the ARG-US RFID equipment and system has been fully tested in two demonstration projects in April 2008 and August 2009. With the strong support of DOE-SR and DOE PCP, a field testing program was completed in Savannah River Site's K-Area Material Storage (KAMS) Facility, an active Category I Plutonium Storage Facility, in 2010. As the next step (Phase II) of continued vault testing for the ARG-US system, the Savannah River Site K Area Material Storage facility has placed the ARG-US RFIDs into the 910B storage vault for operational testing. This latest version (Mark III) of the Argonne RFID system now has the capability to measure radiation dose and dose rate. This paper will report field testing progress of the ARG-US RFID equipment in KAMS, the operability and reliability trend results associated with the applications of the system, and discuss the potential benefits in enhancing safety, security and materials accountability. The purpose of …
Date: June 25, 2012
Creator: Willoner, T.; Turlington, R. & Koenig, R.
Object Type: Article
System: The UNT Digital Library
Polarization Analysis for Seeded FELs in a Crossed-Planar Undulator (open access)

Polarization Analysis for Seeded FELs in a Crossed-Planar Undulator

The crossed-planar undulator is a promising scheme for full polarization control in x-ray FELs. For SASE FELs, it has been shown a maximum degree of circular polarization of about 80% is achievable at fundamental wavelength just before saturation. In this paper, we study the effectiveness of a crossed undulator for a seeded x-ray FEL. The degree of circular polarization for both the fundamental and the harmonic radiation are considered. Simulations with realistic beam distributions show that a degree of circular polarization of over 90% and 80% is obtainable at the fundamental and 2nd harmonic frequencies, respectively.
Date: June 25, 2012
Creator: Geng, Huiping; /SLAC; Ding, Yuantao; /SLAC; Huang, Zhirong; /SLAC et al.
Object Type: Article
System: The UNT Digital Library
Progress in Studies of Electron-Cloud-Induced Optics Distortions at CesrTA (open access)

Progress in Studies of Electron-Cloud-Induced Optics Distortions at CesrTA

The Cornell Electron Storage Ring Test Accelerator (CesrTA) program has included extensive measurements of coherent betatron tune shifts for a variety of electron and positron beam energies, bunch population levels, and bunch train configurations. The tune shifts have been shown to result primarily from the interaction of the beam with the space-charge field of the beam-induced low-energy electron cloud in the vacuum chamber. Comparison to several advanced electron cloud simulation codes has allowed determination of the sensitivity of these measurements to physical parameters characterizing the synchrotron radiation flux, the production of photo-electrons on the vacuum chamber wall, the beam emittance, lattice optics, and the secondary-electron yield model. We report on progress in understanding the cloud buildup and decay mechanisms in magnetic fields and in field-free regions, addressing quantitatively the precise determination of the physical parameters of the modeling. Validation of these models will serve as essential input in the design of damping rings for future high-energy linear colliders.
Date: June 25, 2012
Creator: Crittenden, James; /Cornell U., CLASSE; Calvey, Joseph; /Cornell U., CLASSE; Dugan, Gerald; /Cornell U., CLASSE et al.
Object Type: Article
System: The UNT Digital Library
Recent Bottomonium Results from BaBar and Belle (open access)

Recent Bottomonium Results from BaBar and Belle

Selected studies in bottomonium physics carried out by the BaBar and Belle experiments are presented. They include a study of radiative bottomonium transitions using {gamma} {yields} e{sup +}e{sup -} conversions done by BaBar, the search for the h{sub b}(1P) and h{sub b}(2P) states leading to an evidence for the h{sub b}(1P) seen by BaBar in {Upsilon}(3S) {yields} {pi}{sup 0} h{sub b} decay and to the Belle observation of both the h{sub b}(1P) and the h{sub b}(2P) in the reaction e{sup +}e{sup -} {yields} {pi}{sup +}{pi}{sup -} h{sub b}(1P,2P) from {Upsilon}(5S) data.
Date: June 25, 2012
Creator: Ziegler, Veronique
Object Type: Article
System: The UNT Digital Library
Simulations of Ion Migration in the LCLS RF Gun and Injector (open access)

Simulations of Ion Migration in the LCLS RF Gun and Injector

The motivation for this work was the observed surface contamination of the first LCLS RF gun copper cathode. We will present the results of simulations in regards to ion migration in the LCLS gun. Ions of residual gases will be created by interaction of molecular gas species with the UV drive laser beam and by the electron beam itself. The larger part of those ionized molecules remain in the vicinity of creation, are transported towards beam line walls or away from the cathode. However a small fraction gains enough kinetic energy, focused by RF and magnetic fields and propagates to the cathode, producing an undesirable increase of the cathode's surface work function. Although this fraction is small, during long term operation, this effect may become a significant factor limiting the source performance.
Date: June 25, 2012
Creator: Brachmann, Axel & Dowell, David
Object Type: Article
System: The UNT Digital Library
SMALL-SCALE TESTING OF PLUTONIUM (IV) OXALATE PRECIPITATION AND CALCINATION TO PLUTONIUM OXIDE TO SUPPORT THE MOX FEED MISSION (open access)

SMALL-SCALE TESTING OF PLUTONIUM (IV) OXALATE PRECIPITATION AND CALCINATION TO PLUTONIUM OXIDE TO SUPPORT THE MOX FEED MISSION

The H-Canyon facility will be used to dissolve Pu metal for subsequent purification and conversion to plutonium dioxide (PuO{sub 2}) using Phase II of HB-Line. To support the new mission, SRNL conducted a series of experiments to produce calcined plutonium (Pu) oxide and measure the physical properties and water adsorption of that material. This data will help define the process operating conditions and material handling steps for HB-Line. An anion exchange column experiment produced 1.4 L of a purified 52.6 g/L Pu solution. Over the next nine weeks, seven Pu(IV) oxalate precipitations were performed using the same stock Pu solution, with precipitator feed acidities ranging from 0.77 M to 3.0 M nitric acid and digestion times ranging from 5 to 30 minutes. Analysis of precipitator filtrate solutions showed Pu losses below 1% for all precipitations. The four larger precipitation batches matched the target oxalic acid addition time of 44 minutes within 4 minutes. The three smaller precipitation batches focused on evaluation of digestion time and the oxalic acid addition step ranged from 25-34 minutes because of pump limitations in the low flow range. Following the precipitations, 22 calcinations were performed in the range of 610-690 C, with the largest number …
Date: June 25, 2012
Creator: Crowder, M.; Pierce, R.; Scogin, J.; Daniel, G. & King, W.
Object Type: Report
System: The UNT Digital Library
Status of High Power Tests of Normal Conducting Single-Cell Standing Wave Structures (open access)

Status of High Power Tests of Normal Conducting Single-Cell Standing Wave Structures

Our experiments are directed toward the understanding of the physics of rf breakdown in systems that can be used to accelerate electron beams at {approx}11.4 GHz. The structure geometries have apertures, stored energy per cell, and rf pulse duration close to that of the NLC or CLIC. The breakdown rate is the main parameter that we use to compare rf breakdown behavior for different structures at a given set of rf pulse parameters (pulse shape and peak power) at 60 Hz repetition rate. In our experiments, the typical range of the breakdown rate is from one per few hours to {approx}100 per hour. To date we have tested 29 structures. We consistently found that after the initial conditioning, the behavior of the breakdown rate is reproducible for structures of the same geometry and material, and the breakdown rate dependence on peak magnetic fields is stronger than on peak surface electric fields for structures of different geometries. Below we report the main results from tests of seven structures made from hard copper, soft copper alloys and hard-copper alloys. Additional details on these and other structures will be discussed in future publications.
Date: June 25, 2012
Creator: Dolgashev, Valery; Tantawi, Sami; Yeremian, Anahid; Higashi, Yasuo & Spataro, Bruno
Object Type: Article
System: The UNT Digital Library
A Summary of Taxonomies of Digital System Failure Modes Provided by the DigRel Task Group (open access)

A Summary of Taxonomies of Digital System Failure Modes Provided by the DigRel Task Group

Recently, the CSNI directed WGRisk to set up a task group called DIGREL to initiate a new task on developing a taxonomy of failure modes of digital components for the purposes of PSA. It is an important step towards standardized digital I&C reliability assessment techniques for PSA. The objective of this paper is to provide a comparison of the failure mode taxonomies provided by the participants. The failure modes are classified in terms of their levels of detail. Software and hardware failure modes are discussed separately.
Date: June 25, 2012
Creator: L., Chu T.; M., Yue & Postma, W.
Object Type: Article
System: The UNT Digital Library