Ground motion modeling of Hayward fault scenario earthquakes II:Simulation of long-period and broadband ground motions (open access)

Ground motion modeling of Hayward fault scenario earthquakes II:Simulation of long-period and broadband ground motions

We simulate long-period (T > 1.0-2.0 s) and broadband (T > 0.1 s) ground motions for 39 scenarios earthquakes (Mw 6.7-7.2) involving the Hayward, Calaveras, and Rodgers Creek faults. For rupture on the Hayward fault we consider the effects of creep on coseismic slip using two different approaches, both of which reduce the ground motions compared with neglecting the influence of creep. Nevertheless, the scenario earthquakes generate strong shaking throughout the San Francisco Bay area with about 50% of the urban area experiencing MMI VII or greater for the magnitude 7.0 scenario events. Long-period simulations of the 2007 Mw 4.18 Oakland and 2007 Mw 4.5 Alum Rock earthquakes show that the USGS Bay Area Velocity Model version 08.3.0 permits simulation of the amplitude and duration of shaking throughout the San Francisco Bay area, with the greatest accuracy in the Santa Clara Valley (San Jose area). The ground motions exhibit a strong sensitivity to the rupture length (or magnitude), hypocenter (or rupture directivity), and slip distribution. The ground motions display a much weaker sensitivity to the rise time and rupture speed. Peak velocities, peak accelerations, and spectral accelerations from the synthetic broadband ground motions are, on average, slightly higher than the …
Date: November 4, 2009
Creator: Aagaard, B T; Graves, R W; Rodgers, A; Brocher, T M; Simpson, R W; Dreger, D et al.
Object Type: Article
System: The UNT Digital Library
Construction of the BNL EBIS preinjector (open access)

Construction of the BNL EBIS preinjector

A new heavy ion preinjector, consisting of an Electron Beam Ion Source (EBIS), an RFQ, and IH linac, is under construction at Brookhaven National Laboratory. This preinjector win provide ions of any species at an energy of 2 MeV/u, resulting in increased capabilities for the Relativistic Heavy Ion Collider, and the NASA Space Radiation Laboratory programs. The RF'Q has been commissioned with beam, and most of the remaining elements are either installed or being assembled.
Date: May 4, 2009
Creator: Alessi, J.; Barton, D.; Beebe, E.; Bellavia, S.; Gould, O.; Kponou, A. et al.
Object Type: Article
System: The UNT Digital Library
A Novel Neutron Imaging Calibration System Using a Neutron Generating Accelerator Tube (open access)

A Novel Neutron Imaging Calibration System Using a Neutron Generating Accelerator Tube

Neutron Imaging is a key diagnostic for use in inertial confinement fusion (ICF) experiments, and has been fielded on experiments at Omega and Z. It will also be a key diagnostics at the National Ignition Facility (NIF) located at Lawrence Livermore National Laboratory (LLNL) and eventually at the Laser Megajoule in France. Most systems are based on a neutron pinhole array placed at the target chamber while it is imaged by a scintillating fiber block. The light output of this scintillator is coupled via a reducer to a fiber bundle which transports the image to a CCD camera. Alternatively some systems use optical lens assemblies to focus the light onto a camera.For ICF applications the neutron imaging systems will primarily look at 14.2 MeV neutrons. However, 2.2 MeV and 20+ MeV neutrons will also be present and will potentially provide key information.
Date: September 4, 2009
Creator: Ali, Z., Davis, B., Tinsley, J. R., Miller, E. K.
Object Type: Article
System: The UNT Digital Library
Experimental Studies of Light Emission Phenomena in Superconducting RF Cavitites (open access)

Experimental Studies of Light Emission Phenomena in Superconducting RF Cavitites

Experimental studies of light emission phenomena in superconducting RF cavities, which we categorize under the general heading of cavity lights, are described. The cavity lights data, which were obtained using a small CCD video camera, were collected in a series of nine experimental runs ranging from {approx} 1/2 to {approx} 2 h in duration. The video data were recorded on a standard VHS tape. As the runs progressed, additional instrumentation was added. For the last three runs a LabVIEW controlled data acquisition system was included. These runs furnish evidence for several, possibly related, light emission phenomena. The most intriguing of these is what appear to be small luminous objects {le} 1.5 mm in size, freely moving about in the vacuum space, generally without wall contact, as verified by reflections of the tracks in the cavity walls. In addition, on a number of occasions, these objects were observed to bounce off of the cavity walls. The wall-bounce aspect of most of these events was clearly confirmed by pre-bounce and post-bounce reflections concurrent with the tracks. In one of the later runs, a mode of behavior was observed that was qualitatively different from anything observed in the earlier runs. Perhaps the most …
Date: August 4, 2009
Creator: Anthony, P. L.; Delayen, J. R.; Fryberger, D.; Goree, W. S.; Mammosser, J.; Szalata, Z. M. et al.
Object Type: Article
System: The UNT Digital Library
NANOSTRUCTURED METAL OXIDES FOR ANODES OF LI-ION RECHARGEABLE BATTERIES (open access)

NANOSTRUCTURED METAL OXIDES FOR ANODES OF LI-ION RECHARGEABLE BATTERIES

The aligned nanorods of Co{sub 3}O{sub 4} and nanoporous hollow spheres (NHS) of SnO{sub 2} and Mn{sub 2}O{sub 3} were investigated as the anodes for Li-ion rechargeable batteries. The Co{sub 3}O{sub 4} nanorods demonstrated 1433 mAh/g reversible capacity. The NHS of SnO{sub 2} and Mn{sub 2}O{sub 3} delivered 400 mAh/g and 250 mAh/g capacities respectively in multiple galvonastatic discharge-charge cycles. It was found that high capacity of NHS of metal oxides is sustainable attributed to their unique structure that maintains material integrity during cycling. The nanostructured metal oxides exhibit great potential as the new anode materials for Li-ion rechargeable batteries with high energy density, low cost and inherent safety.
Date: December 4, 2009
Creator: Au, M.
Object Type: Article
System: The UNT Digital Library
The Federal Budget: Current and Upcoming Issues (open access)

The Federal Budget: Current and Upcoming Issues

This report provides information about The Current and Upcoming Issues on Federal Budget. The Federal Budget implements congress's " power of the purse".
Date: November 4, 2009
Creator: Austin, D. Andrew & Levit, Mindy R.
Object Type: Report
System: The UNT Digital Library
First polarized proton collision at a beam energy of 250 GeV in RHIC (open access)

First polarized proton collision at a beam energy of 250 GeV in RHIC

After providing collisions of polarized protons at a beam energy of 100 GeV since 2001, the Relativistic Heavy Ion Collider (RHIC) at BNL had its first opportunity to collide polarized protons at its maximum beam energy of 250 GeV in the 2009 polarized proton operations. Equipped with two full Siberian snakes [1] in each ring, RHIC preserves polarization during acceleration from injection to 100 GeV with precise control of the betatron tunes and vertical orbit distortions. However, the strong intrinsic spin resonances beyond 100 GeV are more than two times stronger than those below 100 GeV, requiring much tighter tolerances on vertical orbit distortions and betatron tunes. With the currently achieved orbit correction and tune control, average polarizations of {approx_equal} 42% at top energy and average polarizations of {approx_equal} 55% at injection energy were achieved. Polarization measurements as a function of beam energy also indicated aU polarization losses occurred around three strong intrinsic resonances at 136 GeV, 199.3 GeV and 220.8 GeV Peak luminosity of 122 x 10{sup 30} cm{sup -2} s{sup -1} was also demonstrated. This paper presents the performance of the first RHIC 250 GeV operation and discusses the depolarization issues encountered during the run.
Date: May 4, 2009
Creator: Bai,M.; Ahrens, L.; Alekseev, I. G.; Alessi, J. & al., et
Object Type: Article
System: The UNT Digital Library
Commissioning of the new AGS MMPS transformers (open access)

Commissioning of the new AGS MMPS transformers

The Brookhaven AGS Main Magnet Power Supply (MMPS) is a thyristor control supply rated at 5500 Amps. +/-9000 Volts. The peak magnet power is 50 MWatts. The power supply is fed from a motor/generator manufactured by Siemens. During rectify and invert operation the P Bank power supplies are used. During the flattops the F Bank power supplies are used. The P Bank power supplies are fed from two 23 MVA transformers and the F Bank power supplies are fed from two 5.3 MYA transformers. The fundamental frequency of the F Bank power supplies is 1440 Hz, however the fundamental frequency of the P banks was 720 Hz. It was very important to reduce the ripple during rectify to improve polarized proton operations. For this reason and also because the original transformers were 45 years old we replaced these transformers with new ones and we made the fundamental frequency of both P and F banks 1440 Hz. This paper will highlight the major hurdles that were involved during the installation of the new transformers. It will present waveforms while running at different power levels up to 6MW full load. It will show the transition from the F-Bank power supplies to the …
Date: May 4, 2009
Creator: Bajon,E.; Badea, V. S.; Bannon, M.; Bonati, R.; Marneris, I. M.; Porqueddu, r. et al.
Object Type: Article
System: The UNT Digital Library
UNDULATOR-BASED LASER WAKEFIELD ACCELERATOR ELECTRON BEAM DIAGNOSTIC (open access)

UNDULATOR-BASED LASER WAKEFIELD ACCELERATOR ELECTRON BEAM DIAGNOSTIC

to couple the THUNDER undulator to the LOASIS Lawrence Berkeley National Laboratory (LBNL) laser wakefield accelerator (LWFA). Currently the LWFA has achieved quasi-monoenergetic electron beams with energies up to 1 GeV. These ultra-short, high-peak-current, electron beams are ideal for driving a compact XUV free electron laser (FEL). Understanding the electron beam properties such as the energy spread and emittance is critical for achieving high quality light sources with high brightness. By using an insertion device such as an undulator and observing changes in the spontaneous emission spectrum, the electron beam energy spread and emittance can be measured with high precision. The initial experiments will use spontaneous emission from 1.5 m of undulator. Later experiments will use up to 5 m of undulator with a goal of a high gain, XUV FEL.
Date: May 4, 2009
Creator: Bakeman, M.S.; Fawley, W.M.; Leemans, W. P.; Nakamura, K.; Robinson, K.E.; Schroeder, C.B. et al.
Object Type: Article
System: The UNT Digital Library
Political Status of Puerto Rico: Options for Congress (open access)

Political Status of Puerto Rico: Options for Congress

This report discusses the current U.S.-Puerto Rico relationship, the history of said relationship, and the current political state of Puerto Rico, as well as relevant pieces of U.S. Congressional legislation concerning Puerto Rico.
Date: August 4, 2009
Creator: Bea, Keith & Garrett, R. Sam
Object Type: Report
System: The UNT Digital Library
U.S. - EU Poultry Dispute (open access)

U.S. - EU Poultry Dispute

This report discusses the European Union (EU) refusal to accept U.S. imports of poultry treated with antimicrobial rinses. Prior to 1997, when the prohibition took effect, U.S. exports of broiler and turkey meat to the 15 countries that then constituted the EU were reported to total nearly 32,000 MT with a value of $44.4 million.
Date: February 4, 2009
Creator: Becker, Geoffrey S.
Object Type: Report
System: The UNT Digital Library
Investigation of the radiation background in the interaction region of the medium-energy electron relativisitic heavy ion collider (MeRHIC) (open access)

Investigation of the radiation background in the interaction region of the medium-energy electron relativisitic heavy ion collider (MeRHIC)

There are three main sources of the radiation background in MeRHIC: forward synchrotron radiation generated upstream of the detector, the direct backward radiation caused by the photons hitting beampipe downstream of the detector, and the indirect secondary radiation caused by hard photons hitting vacuum systems, masks, collimators, absorbers or any other elements in the interaction region. In this paper, we first calculate the primary radiation distribution by employing electromagnetic theory. Then we obtain the direct backward scattering rate by applying the kinematic Born approximation deduced from scattering dynamics. The diffuse scattering cross section is calculated as a function of the surface properties of the MeRHIC vacuum system. Finally, the dominating physical processes and minimization of indirect secondary radiation is presented and discussed.
Date: May 4, 2009
Creator: Beebe-Wang, J.
Object Type: Article
System: The UNT Digital Library
Statistical analysis of multipole components in the magnetic field of the RHIC arc regions (open access)

Statistical analysis of multipole components in the magnetic field of the RHIC arc regions

The existence of multipolar components in the dipole and quadrupole magnets is one of the factors limiting the beam stability in the RHIC operations. Therefore, the statistical properties of the non-linear fields are crucial for understanding the beam behavior and for achieving the superior performance in RHIC. In an earlier work [1], the field quality analysis of the RHIC interaction regions (IR) was presented. Furthermore, a procedure for developing non-linear IR models constructed from measured multipolar data of RHIC IR magnets was described. However, the field quality in the regions outside of the RHIC IR had not yet been addressed. In this paper, we present the statistical analysis of multipolar components in the magnetic fields of the RHIC arc regions. The emphasis is on the lower order components, especially the sextupole in the arc dipole and the 12-pole in the quadrupole magnets, since they are shown to have the strongest effects on the beam stability. Finally, the inclusion of the measured multipolar components data of RHIC arc regions and their statistical properties into tracking models is discussed.
Date: May 4, 2009
Creator: Beebe-Wang, J. & Jain, A.
Object Type: Article
System: The UNT Digital Library
Observation and simulation of beam-beam induced emittance growth in RHIC (open access)

Observation and simulation of beam-beam induced emittance growth in RHIC

In the recent years the peak luminosity of the RHIC polarized proton run has been improved. However, as a consequence, the luminosity lifetime is reduced. The beam emittance growth during the beam storage is a main contributor to the luminosity lifetime reduction, and it seems to be caused mainly by the beam-beam effect during collision. A simulation study of the emittance growth is performed with RHIC machine parameters using the LIFETRAC code [1]. The initial results of this study were reported in an earlier paper [2]. We present, in this paper, an in depth investigation of the emittance growth for a range of beam-beam parameters and bunch lengths. The simulation results are also compared to the available data from experimental measurements.
Date: May 4, 2009
Creator: Beebe-Wang, J. & Zhang, S. Y.
Object Type: Article
System: The UNT Digital Library
An Injection/Extraction Scenario for EMMA (open access)

An Injection/Extraction Scenario for EMMA

EMMA is an experiment to study beam dynamics in a linear non-scaling fixed-field alternating gradient accelerator (FFAG). It accelerates an electron beam from 10 to 20 MeV kinetic energy. To optimally perform these studies, one must be able to inject the beam at any energy within the machine's energy range. Furthermore, because we wish to study the behavior of large-emittance beams in such a machine, the injection systems must be able to inject the beam anywhere within a transverse phase space ellipse with a normalized acceptance of 3 mm, and the extraction systems must be able to extract from that same ellipse. I describe a computation of kicker and septum fields to achieve all of these requirements, and discuss how this interacts with the hardware constraints.
Date: May 4, 2009
Creator: Berg, J. S.
Object Type: Article
System: The UNT Digital Library
FFAG Designs for the International Design Study for the Neutrino Factory (open access)

FFAG Designs for the International Design Study for the Neutrino Factory

The International Design Study for the Neutrino Factory (IDS-NF) aims to produce a design report for a neutrino factory. One component of that design is a linear nonscaling fixed-field alternating gradient accelerator (FFAG) that will accelerate to the final energy of 25 GeV. An FFAG is used to reduce the machine cost by maximizing the number of passes made through the RF cavities. We present some design options for this FFAG, individually optimized for cost. We study the addition of nonlinear magnets to the lattice to improve the performance of the lattice and consider the negative effects of doing so.
Date: May 4, 2009
Creator: Berg, J. S. & Machida, S.
Object Type: Article
System: The UNT Digital Library
PS2007 Satellite Meeting on Photosynthetic Antennas, 19-22 July 2007, Drymen, Scotland (open access)

PS2007 Satellite Meeting on Photosynthetic Antennas, 19-22 July 2007, Drymen, Scotland

A Satellite Workshop of the 14th International Congress on Photosynthesis on the topic of photosynthetic light-harvesting systems was held on 18-21 July 2007, at the Buchanan Arms Hotel in Drymen, Scotland, near Glasgow. This meeting continued the tradition of satellite light-harvesting conferences occurring prior to the last five international photosynthesis congresses in Japan, France, Hungary, Australia and Canada, dating from 1992. With an attendance of 124 participants, this Workshop represents an intimate gathering of scientists interested in a thorough coverage of the light-harvesting aspects of photosynthesis. A significant amount of time was set aside for discussion and poster sessions. The organizers were: Richard J. Cogdell, UK (Chairperson), Alastair T. Gardiner, UK, Conrad W. Mullineaux, UK, Robert A. Niederman, USA, Robert E. Blankenship, USA, Harry Frank, USA, Bruno Robert, France. Sessions were focused on new concepts relating to the function, regulation, assembly, photoprotection and evolution of a wide variety of antenna systems. Cutting-edge scientific methods used to study these systems that were covered included time-resolved and single-molecule spectroscopy, structure determination by X-ray diffraction, NMR and electron and atomic force microscopy, molecular genetics, protein chemistry, model systems and theory. A central theme was how emerging high-resolution structural information on antenna proteins continues …
Date: June 4, 2009
Creator: Blankenship, Robert E.
Object Type: Report
System: The UNT Digital Library
Landau damping with high frequency impedance (open access)

Landau damping with high frequency impedance

Coupled bunch longitudinal stability in the presence of high frequency impedances is considered. A frequency domain technique is developed and compared with simulations. The frequency domain technique allows for absolute stability tests and is applied to the problem of longitudinal stability in RHIC with the new 56 MHz RF system.
Date: May 4, 2009
Creator: Blaskiewicz, M.
Object Type: Article
System: The UNT Digital Library
Infrared Extraction Change for the NSLS-II Storage Ring (open access)

Infrared Extraction Change for the NSLS-II Storage Ring

The short- and long-range wakepotentials have been studied for the design of the infrared (IR) extraction chamber with large full aperture: 67mm vertical and 134mm horizontal. The IR-chamber will be installed within a 2.6m long wide-gap bending magnet with 25m bend radius. Due to the large bend radius it is difficult to separate the light from the electron trajectory. The required parameters of the collected IR radiation at the extraction mirror are {approx}50mrad horizontal and {approx}25mrad vertical (full radiation opening angles). If the extraction mirror is seen by the beam, resonant modes are generated in the chamber. In this paper, we present the detailed calculated impedance for the design of the far-IR chamber, and show that placing the extraction mirror in the proper position eliminates the resonances. In this case, the impedance reduces to that of a simple tapered structure, which is acceptable in regard to its impact on the electron beam.
Date: May 4, 2009
Creator: Blednykh,A.; Carr, L.; Coburn, D. & Krinsky, S.
Object Type: Article
System: The UNT Digital Library
Impedance Calculations for the NSLS-II Storage Rings (open access)

Impedance Calculations for the NSLS-II Storage Rings

Impedance of two vacuum chamber components, Bellows and BPM, is considered in some detail. In order to avoid generation of Higher-Order Modes (HOM's) in the NSLS-II bellows, we designed a new low-impedance RF shielding consisting of 6 wide and 2 narrow metal plates without opening slots between them. The short-range wakepotential has been optimized taking into account vertical offset of RF fingers from their nominal position. The results were compared with data of bellows designed at other laboratories. Narrow-band impedance of the BPM Button has been studied. TE-modes in the BPM button were suppressed by a factor of 8 by modification of existing housings. Two new types of housings are shown. The total impedance of the NSLS-II storage ring is discussed in terms of the loss factor and the vertical kick factor for a 3mm-Gaussian bunch.
Date: May 4, 2009
Creator: Blednykh,A.; Ferreira, M. & Krinsky, S.
Object Type: Article
System: The UNT Digital Library
Microwave Instability Simulations for NSLS-II (open access)

Microwave Instability Simulations for NSLS-II

Potential-well distortion and the microwave instability in the NSLS-II storage ring are investigated. The longitudinal wakepotential is calculated as a sum of the contributions due to vacuum chamber components distributed around the ring. An approximation to the wakepotential for a 0.05-mm charge distribution length, much shorter than the 4.5-mm length of the unperturbed circulating bunch, is used as a pseudo-Green's function for beam dynamics simulations. Comparison of particle tracking simulations using the TRANFT code with the Haissinski solution shows good agreement below the instability threshold current. Above threshold two regimes are observed: (1) energy spread and bunch length are time-dependent (saw tooth behavior); (2) both are time-independent.
Date: May 4, 2009
Creator: Blednykh,A.; Krinsky, S.; Nash, B. & Yu, L.
Object Type: Article
System: The UNT Digital Library
Protect and Restore Red River Watershed, 2007-2008 Annual Report. (open access)

Protect and Restore Red River Watershed, 2007-2008 Annual Report.

The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridge-top approach. The Nez Perce Tribe (NPT) and the Nez Perce National Forest (NPNF) have formed a partnership in completing watershed restoration activities, and through this partnership more work is accomplished by sharing funding and resources in our effort. The Nez Perce Tribe began watershed restoration projects within the Red River Watershed of the South Fork Clearwater River in 2001. Progress has been made in restoring the watershed through road decommissioning and culvert replacement. From completing a watershed assessment to two NEPA efforts and a final stream restoration design, we will begin the effort of restoring the mainstem channel of Red River to provide spawning and rearing habitat for anadromous and resident fish species. Roads have been surveyed and prioritized for removal or improvement as well as culverts being prioritized for replacement to accommodate fish passage throughout the watershed. Another major, and extremely, important component of this project is the Red River Meadow Conservation Easement. We have begun the process of pursuing a conservation easement on approximately 270 acres of prime meadow habitat (Red River runs through this meadow and is prime …
Date: May 4, 2009
Creator: Bransford, Stephanie
Object Type: Report
System: The UNT Digital Library
Molecular-Genetic Analysis of Osmoregulation, Osmotic Adjustment and Growth in Arabidopsis (open access)

Molecular-Genetic Analysis of Osmoregulation, Osmotic Adjustment and Growth in Arabidopsis

The molecular mechanism by which plants control cellular solute and water content, called osmoregulation, is critical for cell expansion and survival, particularly in response to cellular water deficit or low water potential. Two loci, lwr1 and lwr2 (low water potential response), that affect osmoregulation were isolated as part of a larger screen to identify mutants with alterations in low water potential-induced proline accumulation. When seedlings of lwr2 were exposed to a steady low water potential stress over a period of several days using PEG-infused agar plates, the mutants had lesser proline accumulation and osmotic adjustment than the wild type, Ben. A mapping population was raised but it was not possible to reliably identify the mutants in the population and thus could not be used for mapping. The mutant lwr1 was mapped and the gene identified. The mutant lwr1 had greater accumulation of proline, higher total solute content, greater osmotic adjustment at low water potential, altered abscisic acid content, and increased sensitivity to applied abscisic acid with respect to Pro content than the wild type, Ben, when the water potential was decreased over a period of several days using PEG-infused agar plates. lwr1 also had altered growth and morphology, including defects …
Date: May 4, 2009
Creator: Bray, Elizabeth
Object Type: Report
System: The UNT Digital Library
Stochastic cooling in RHIC (open access)

Stochastic cooling in RHIC

After the success of longitudinal stochastic cooling of bunched heavy ion beam in RHIC, transverse stochastic cooling in the vertical plane of Yellow ring was installed and is being commissioned with proton beam. This report presents the status of the effort and gives an estimate, based on simulation, of the RHIC luminosity with stochastic cooling in all planes.
Date: May 4, 2009
Creator: Brennan,J. M.; Blaskiewicz, M. M. & Severino, F.
Object Type: Article
System: The UNT Digital Library