Final Report for Phase I Northern California CO2 Reduction Project (open access)

Final Report for Phase I Northern California CO2 Reduction Project

On June 8, 2009, the U. S. Department of Energy's National Energy Technology Laboratory released a Funding Opportunity Announcement (DE-FOA 0000015) with the title, Recovery Act: Carbon Capture and Sequestration from Industrial Sources and Innovative Concepts for Beneficial CO{sub 2} Use. C6 Resources (C6), an affiliate of Shell Oil Company, responded with a proposal for Technology Area 1: Large-scale industrial carbon capture and sequestration (CCS) projects from industrial sources. As DOE Federally Funded Research and Development Center (FFRDC) Contractors, Lawrence Livermore National Laboratory (LBNL) and Lawrence Berkeley National Laboratory (LLNL) proposed to collaborate with C6 and perform technical tasks, which C6 included in the C6 proposal, titled the Northern California CO{sub 2} Reduction Project. The proposal was accepted for Phase I funding and C6 received DOE Award DEFE0002042. LLNL and LBNL each received Phase I funding of $200,000, directly from DOE. The essential task of Phase I was to prepare a proposal for Phase II, which would be a five-year, detailed technical proposal, budget, and schedule for a complete carbon capture, transportation, and geologic storage project, with the objective of starting the injection of 1 million tons per year of industrial CO2 by the end of FY2015. LLNL and LBNL …
Date: October 26, 2010
Creator: Wagoner, J
Object Type: Report
System: The UNT Digital Library
Flavor Physics in the Quark Sector (open access)

Flavor Physics in the Quark Sector

In the past decade, one of the major challenges of particle physics has been to gain an in-depth understanding of the role of quark flavor. In this time frame, measurements and the theoretical interpretation of their results have advanced tremendously. A much broader understanding of flavor particles has been achieved, apart from their masses and quantum numbers, there now exist detailed measurements of the characteristics of their interactions allowing stringent tests of Standard Model predictions. Among the most interesting phenomena of flavor physics is the violation of the CP symmetry that has been subtle and difficult to explore. In the past, observations of CP violation were confined to neutral K mesons, but since the early 1990s, a large number of CP-violating processes have been studied in detail in neutral B mesons. In parallel, measurements of the couplings of the heavy quarks and the dynamics for their decays in large samples of K,D, and B mesons have been greatly improved in accuracy and the results are being used as probes in the search for deviations from the Standard Model. In the near future, there will be a transition from the current to a new generation of experiments, thus a review of …
Date: August 26, 2010
Creator: Antonelli, Mario; Asner, David Mark; Bauer, Daniel Adams; Becher, Thomas G.; Beneke, M.; Bevan, Adrian John et al.
Object Type: Article
System: The UNT Digital Library
The Formation of Population III Binaries from Cosmological Initial Conditions (open access)

The Formation of Population III Binaries from Cosmological Initial Conditions

Previous high resolution cosmological simulations predict the first stars to appear in the early universe to be very massive and to form in isolation. Here we discuss a cosmological simulation in which the central 50M{sub {circle_dot}} clump breaks up into two cores, having a mass ratio of two to one, with one fragment collapsing to densities of 10{sup -8}g cm{sup -3}. The second fragment, at a distance of {approx}800 astronomical units, is also optically thick to its own cooling radiation from molecular hydrogen lines, but is still able to cool via collision-induced emission. The two dense peaks will continue to accrete from the surrounding cold gas reservoir over a period of {approx} 10{sup 5} years and will likely form a binary star system.
Date: August 26, 2010
Creator: Turk, Matthew J.; Abel, Tom; /KIPAC, Menlo Park; O'Shea, Brian W. & U., /Michigan State
Object Type: Article
System: The UNT Digital Library
FPGA Based Real-time Network Traffic Analysis using Traffic Dispersion Patterns (open access)

FPGA Based Real-time Network Traffic Analysis using Traffic Dispersion Patterns

The problem of Network Traffic Classification (NTC) has attracted significant amount of interest in the research community, offering a wide range of solutions at various levels. The core challenge is in addressing high amounts of traffic diversity found in today's networks. The problem becomes more challenging if a quick detection is required as in the case of identifying malicious network behavior or new applications like peer-to-peer traffic that have potential to quickly throttle the network bandwidth or cause significant damage. Recently, Traffic Dispersion Graphs (TDGs) have been introduced as a viable candidate for NTC. The TDGs work by forming a network wide communication graphs that embed characteristic patterns of underlying network applications. However, these patterns need to be quickly evaluated for mounting real-time response against them. This paper addresses these concerns and presents a novel solution for real-time analysis of Traffic Dispersion Metrics (TDMs) in the TDGs. We evaluate the dispersion metrics of interest and present a dedicated solution on an FPGA for their analysis. We also present analytical measures and empirically evaluate operating effectiveness of our design. The mapped design on Virtex-5 device can process 7.4 million packets/second for a TDG comprising of 10k flows at very high accuracies …
Date: March 26, 2010
Creator: Khan, F.; Gokhale, M. & Chuah, C. N.
Object Type: Article
System: The UNT Digital Library
Global F-theory GUTs (open access)

Global F-theory GUTs

We construct global F-theory GUT models on del Pezzo surfaces in compact Calabi-Yau fourfolds realized as complete intersections of two hypersurface constraints. The intersections of the GUT brane and the flavour branes as well as the gauge flux are described by the spectral cover construction. We consider a split S[U(4) x U(1){sub X}] spectral cover, which allows for the phenomenologically relevant Yukawa couplings and GUT breaking to the MSSM via hypercharge flux while preventing dimension-4 proton decay. General expressions for the massless spectrum, consistency conditions and a new method for the computation of curvature-induced tadpoles are presented. We also provide a geometric toolkit for further model searches in the framework of toric geometry. Finally, an explicit global model with three chiral generations and all required Yukawa couplings is defined on a Calabi-Yau fourfold which is fibered over the del Pezzo transition of the Fano threefold P{sup 4}.
Date: August 26, 2010
Creator: Blumenhagen, Ralph; Grimm, Thomas W.; Jurke, Benjamin & Weigand, Timo
Object Type: Article
System: The UNT Digital Library
Gluon Evolution and Saturation Proceedings (open access)

Gluon Evolution and Saturation Proceedings

Almost 40 years ago, Gribov and colleagues at the Leningrad Nuclear Physics Institute developed the ideas that led to the Dokhsitzer-Gribov-Altarelli-Parisi the Baltisky-Fadin-Kuraev-Lipatov equations. These equations describe the evolution of the distributions for quarks and gluon inside a hadron to increased resolution scale of a probe or to smaller values of the fractional momentum of a hadronic constituent. I motivate and discuss the generalization required of these equations needed for high energy processes when the density of constituents is large. This leads to a theory of saturation realized by the Color Glass Condensate
Date: May 26, 2010
Creator: McLerran, L. D.
Object Type: Article
System: The UNT Digital Library
Gravity Waves and Linear Inflation From Axion Monodromy (open access)

Gravity Waves and Linear Inflation From Axion Monodromy

Wrapped branes in string compactifications introduce a monodromy that extends the field range of individual closed-string axions to beyond the Planck scale. Furthermore, approximate shift symmetries of the system naturally control corrections to the axion potential. This suggests a general mechanism for chaotic inflation driven by monodromy-extended closed-string axions. We systematically analyze this possibility and show that the mechanism is compatible with moduli stabilization and can be realized in many types of compactifications, including warped Calabi-Yau manifolds and more general Ricci-curved spaces. In this broad class of models, the potential is linear in the canonical inflaton field, predicting a tensor to scalar ratio r {approx} 0.07 accessible to upcoming cosmic microwave background (CMB) observations.
Date: August 26, 2010
Creator: McAllister, Liam; /Cornell U., LEPP /Cornell U., Phys. Dept.; Silverstein, Eva; Westphal, Alexander & /SLAC /Stanford U., Phys. Dept.
Object Type: Article
System: The UNT Digital Library
A Hybrid Higgs (open access)

A Hybrid Higgs

We construct composite Higgs models admitting a weakly coupled Seiberg dual description. We focus on the possibility that only the up-type Higgs is an elementary field, while the down-type Higgs arises as a composite hadron. The model, based on a confining SQCD theory, breaks supersymmetry and electroweak symmetry dynamically and calculably. This simultaneously solves the {mu}/B{sub {mu}} problem and explains the smallness of the bottom and tau masses compared to the top mass. The proposal is then applied to a class of models where the same confining dynamics is used to generate the Standard Model flavor hierarchy by quark and lepton compositeness. This provides a unified framework for flavor, supersymmetry breaking and electroweak physics. The weakly coupled dual is used to explicitly compute the MSSM parameters in terms of a few microscopic couplings, giving interesting relations between the electroweak and soft parameters. The RG evolution down to the TeV scale is obtained and salient phenomenological predictions of this class of 'single-sector' models are discussed.
Date: August 26, 2010
Creator: Schafer-Nameki, Sakura; Tamarit, Carlos; /Santa Barbara, KITP; Torroba, Gonzalo & /SLAC /Santa Barbara, KITP
Object Type: Report
System: The UNT Digital Library
Illumination Sufficiency Survey Techniques: In-situ Measurements of Lighting System Performance and a User Preference Survey for Illuminance in an Off-Grid, African Setting (open access)

Illumination Sufficiency Survey Techniques: In-situ Measurements of Lighting System Performance and a User Preference Survey for Illuminance in an Off-Grid, African Setting

Efforts to promote rechargeable electric lighting as a replacement for fuel-based light sources in developing countries are typically predicated on the notion that lighting service levels can be maintained or improved while reducing the costs and environmental impacts of existing practices. However, the extremely low incomes of those who depend on fuel-based lighting create a need to balance the hypothetically possible or desirable levels of light with those that are sufficient and affordable. In a pilot study of four night vendors in Kenya, we document a field technique we developed to simultaneously measure the effectiveness of lighting service provided by a lighting system and conduct a survey of lighting service demand by end-users. We took gridded illuminance measurements across each vendor's working and selling area, with users indicating the sufficiency of light at each point. User light sources included a mix of kerosene-fueled hurricane lanterns, pressure lamps, and LED lanterns.We observed illuminance levels ranging from just above zero to 150 lux. The LED systems markedly improved the lighting service levels over those provided by kerosene-fueled hurricane lanterns. Users reported that the minimum acceptable threshold was about 2 lux. The results also indicated that the LED lamps in use by the …
Date: August 26, 2010
Creator: Alstone, Peter; Jacobson, Arne & Mills, Evan
Object Type: Report
System: The UNT Digital Library
IMPEDANCE CONSIDERATIONS FOR THE DESIGN OF THE VACUUM SYSTEM OF THE CERN PS2 (open access)

IMPEDANCE CONSIDERATIONS FOR THE DESIGN OF THE VACUUM SYSTEM OF THE CERN PS2

In order for the LHC to reach an ultimate luminosity goal of 10{sup 35}/cm{sup 2}/s, CERN is considering upgrade options for the LHC injector chain, including a new 50 GeV synchrotron of about 1.3 km length for protons and heavy ions, to be called the PS2 [1]. The proton energy will be ramped from 4 GeV to 50 GeV in 1.2 s, and the design proton current for LHC operation is 2.7 A. In the LARP framework, we are studying the instability thresholds and the impedance requirements of the vacuum system for the PS2. Goal of this study is to develop an impedance budget for the machine. We consider the standard single and multi-bunch collective effects that may be an issue in the PS2. For single bunch, we study the microwave instability and the transverse mode coupling instability (TMCI); for multi-bunch, the transverse coupled bunch instability. While the impedance budget will include many components in the machine, at present, we only have sufficient information to include the resistance of the beam pipe, the vacuum flanges that connect the various pieces of the vacuum chamber, and space charge impedance in our estimate. Note that earlier estimates of the impedance and its …
Date: August 26, 2010
Creator: Bane, K.L.F.; Stupakov, G.; Wienands, U.; Benedikt, M.; Grudiev, A.; Mahner, E. et al.
Object Type: Article
System: The UNT Digital Library
Improved Meteorological Input for Atmospheric Release Decision support Systems and an Integrated LES Modeling System for Atmospheric Dispersion of Toxic Agents: Homeland Security Applications (open access)

Improved Meteorological Input for Atmospheric Release Decision support Systems and an Integrated LES Modeling System for Atmospheric Dispersion of Toxic Agents: Homeland Security Applications

When hazardous material is accidently or intentionally released into the atmosphere, emergency response organizations look to decision support systems (DSSs) to translate contaminant information provided by atmospheric models into effective decisions to protect the public and emergency responders and to mitigate subsequent consequences. The Department of Homeland Security (DHS)-led Interagency Modeling and Atmospheric Assessment Center (IMAAC) is one of the primary DSSs utilized by emergency management organizations. IMAAC is responsible for providing 'a single piont for the coordination and dissemination of Federal dispersion modeling and hazard prediction products that represent the Federal position' during actual or potential incidents under the National Response Plan. The Department of Energy's (DOE) National Atmospheric Release Advisory Center (NARAC), locatec at the Lawrence Livermore National Laboratory (LLNL), serves as the primary operations center of the IMAAC. A key component of atmospheric release decision support systems is meteorological information - models and data of winds, turbulence, and other atmospheric boundary-layer parameters. The accuracy of contaminant predictions is strongly dependent on the quality of this information. Therefore, the effectiveness of DSSs can be enhanced by improving the meteorological options available to drive atmospheric transport and fate models. The overall goal of this project was to develop and …
Date: April 26, 2010
Creator: Arnold, E; Simpson, M; Larsen, S; Gash, J; Aluzzi, F; Lundquist, J et al.
Object Type: Report
System: The UNT Digital Library
INDEPENDENT VERIFICATION REVIEW AND SURVEY of the Argonne National Laboratory Building 301 Footprint (open access)

INDEPENDENT VERIFICATION REVIEW AND SURVEY of the Argonne National Laboratory Building 301 Footprint

INDEPENDENT VERIFICATION REVIEW AND SURVEY of the Argonne National Laboratory Building 301 Footprint, Argonne Illinois 5061-SR-01-0
Date: May 26, 2010
Creator: Bailey, E.N.
Object Type: Report
System: The UNT Digital Library
'Insightful D-branes' (open access)

'Insightful D-branes'

We study a simple model of a black hole in AdS and obtain a holographic description of the region inside the horizon. A key role is played by the dynamics of the scalar fields in the dual gauge theory. This leads to a proposal for a dual description of D-branes falling through the horizon of any AdS black hole. The proposal uses a field-dependent time reparameterization in the field theory. We relate this reparametrization to various gauge invariances of the theory. Finally, we speculate on information loss and the black hole singularity in this context.
Date: August 26, 2010
Creator: Horowitz, Gary; /UC, Santa Barbara; Lawrence, Albion; /Brandeis U. /Santa Barbara, KITP; Silverstein, Eva & /SLAC /Stanford U., Phys. Dept. /Santa Barbara, KITP
Object Type: Article
System: The UNT Digital Library
Integrated Nucleosynthesis in Neutrino Driven Winds (open access)

Integrated Nucleosynthesis in Neutrino Driven Winds

Although they are but a small fraction of the mass ejected in core-collapse supernovae, neutrino-driven winds (NDWs) from nascent proto-neutron stars (PNSs) have the potential to contribute significantly to supernova nucleosynthesis. In previous works, the NDW has been implicated as a possible source of r-process and light p-process isotopes. In this paper we present time-dependent hydrodynamic calculations of nucleosynthesis in the NDW which include accurate weak interaction physics coupled to a full nuclear reaction network. Using two published models of PNS neutrino luminosities, we predict the contribution of the NDW to the integrated nucleosynthetic yield of the entire supernova. For the neutrino luminosity histories considered, no true r-process occurs in the most basic scenario. The wind driven from an older 1.4M{sub {circle_dot}} model for a PNS is moderately neutron-rich at late times however, and produces {sup 87}Rb, {sup 88}Sr, {sup 89}Y, and {sup 90}Zr in near solar proportions relative to oxygen. The wind from a more recently studied 1.27M{sub {circle_dot}} PNS is proton-rich throughout its entire evolution and does not contribute significantly to the abundance of any element. It thus seems very unlikely that the simplest model of the NDW can produce the r-process. At most, it contributes to the …
Date: March 26, 2010
Creator: Roberts, L F; Woosley, S E & Hoffman, R D
Object Type: Article
System: The UNT Digital Library
Internal Electric Field Behavior of Cadmium Zinc Telluride Radiation Detectors Under High Carrier Injection (open access)

Internal Electric Field Behavior of Cadmium Zinc Telluride Radiation Detectors Under High Carrier Injection

The behavior of the internal electric-field of nuclear-radiation detectors substantially affects the detector's performance. We investigated the distribution of the internal field in cadmium zinc telluride (CZT) detectors under high carrier injection. We noted the build-up of a space charge region near the cathode that produces a built-in field opposing the applied field. Its presence entails the collapse of the electric field in the rest of detector, other than the portion near the cathode. Such a space-charge region originates from serious hole-trapping in CZT. The device's operating temperature greatly affects the width of the space-charge region. With increasing temperature from 5 C to 35 C, its width expanded from about 1/6 to 1/2 of the total depth of the detector.
Date: October 26, 2010
Creator: Yang, G.; Bolotnikov, A. E.; Camarda, G. S.; Cui, Y.; Hossain, A.; Kim, K. H. et al.
Object Type: Article
System: The UNT Digital Library
Kinetics of Ejected Particles During Laser-Induced Breakdown in Fused Silica (open access)

Kinetics of Ejected Particles During Laser-Induced Breakdown in Fused Silica

None
Date: July 26, 2010
Creator: Raman, R N; Negres, R A & Demos, S G
Object Type: Article
System: The UNT Digital Library
Large-N reduction in QCD-like theories with massive adjoint fermions (open access)

Large-N reduction in QCD-like theories with massive adjoint fermions

Large-N QCD with heavy adjoint fermions emulates pure Yang-Mills theory at long distances. We study this theory on a four- and three-torus, and analytically argue the existence of a large-small volume equivalence. For any finite mass, center symmetry unbroken phase exists at sufficiently small volume and this phase can be used to study the large-volume limit through the Eguchi-Kawai equivalence. A finite temperature version of volume independence implies that thermodynamics on R3 x S1 can be studied via a unitary matrix quantum mechanics on S1, by varying the temperature. To confirm this non-perturbatively, we numerically study both zero- and one-dimensional theories by using Monte-Carlo simulation. Order of finite-N corrections turns out to be 1/N. We introduce various twisted versions of the reduced QCD which systematically suppress finite-N corrections. Using a twisted model, we observe the confinement/deconfinement transition on a 1{sup 3} x 2-lattice. The result agrees with large volume simulations of Yang-Mills theory. We also comment that the twisted model can serve as a non-perturbative formulation of the non-commutative Yang-Mills theory.
Date: August 26, 2010
Creator: Azeyanagi, Tatsuo; U., /Kyoto; Hanada, Masanori; Inst., /Weizmann; Unsal, Mithat; /Weizmann Inst. /SLAC /Stanford U., Phys. Dept. et al.
Object Type: Article
System: The UNT Digital Library
Large-N volume independence in conformal and confining gauge theories (open access)

Large-N volume independence in conformal and confining gauge theories

Consequences of large N volume independence are examined in conformal and confining gauge theories. In the large N limit, gauge theories compactified on R{sup d-k} x (S{sup 1}){sup k} are independent of the S{sup 1} radii, provided the theory has unbroken center symmetry. In particular, this implies that a large N gauge theory which, on R{sup d}, flows to an IR fixed point, retains the infinite correlation length and other scale invariant properties of the decompactified theory even when compactified on R{sup d-k} x (S{sup 1}){sup k}. In other words, finite volume effects are 1/N suppressed. In lattice formulations of vector-like theories, this implies that numerical studies to determine the boundary between confined and conformal phases may be performed on one-site lattice models. In N = 4 supersymmetric Yang-Mills theory, the center symmetry realization is a matter of choice: the theory on R{sup 4-k} x (S{sup 1}){sup k} has a moduli space which contains points with all possible realizations of center symmetry. Large N QCD with massive adjoint fermions and one or two compactified dimensions has a rich phase structure with an infinite number of phase transitions coalescing in the zero radius limit.
Date: August 26, 2010
Creator: Unsal, Mithat & Yaffe, Laurence G.
Object Type: Article
System: The UNT Digital Library
Laser-induced Ramp Compression of Tantalum and Iron to Over 300 GPa: EOS and X-ray Diffraction (open access)

Laser-induced Ramp Compression of Tantalum and Iron to Over 300 GPa: EOS and X-ray Diffraction

None
Date: January 26, 2010
Creator: Eggert, J. H.; Bastea, M.; Braun, D.; Fujino, D.; Rygg, R.; Smith, R. et al.
Object Type: Article
System: The UNT Digital Library
Lessons Learned from PEP-II LLRF and Longitudinal Feedback (open access)

Lessons Learned from PEP-II LLRF and Longitudinal Feedback

The PEP-II B-Factory collider ended the final phase of operation at nearly twice the design current and 4X the design luminosity. To highlight the evolution from the original conceptual design through to the 1.2E34 final machine we choose one example each from the broadband feedback and from the LLRF system. They illustrate the original design estimation missed some very significant details, and how in the course of PEP-II operation unexpected difficulties led to significant insights and new approaches which allowed higher machine performance. We present valuable 'lessons learned' which are of interest to designers of next generation feedback and impedance controlled LLRF systems.
Date: August 26, 2010
Creator: Fox, J. D.; Mastorides, T.; Rivetta, C. H.; Van Winkle, D. & Teytelman, D.
Object Type: Article
System: The UNT Digital Library
Light-Front Quantization Approach to the Gauge Gravity Correspondence and Hadron Spectroscopy (open access)

Light-Front Quantization Approach to the Gauge Gravity Correspondence and Hadron Spectroscopy

We find a correspondence between semiclassical QCD quantized on the light-front and a dual gravity model in anti-de Sitter (AdS) space, thus providing an initial approximation to QCD in its strongly coupled regime. This correspondence - light-front holography - leads to a light-front Hamiltonian and relativistic bound-state wave equations that are functions of an invariant impact variable {zeta} which measures the separation of the quark and gluonic constituents within hadrons at equal lightfront time. The eigenvalues of the resulting light-front Schrodinger and Dirac equations are consistent with the observed light meson and baryon spectrum, and the eigenmodes provide the light-front wavefunctions, the probability amplitudes describing the dynamics of the hadronic constituents. The light-front equations of motion, which are dual to an effective classical gravity theory, possess remarkable algebraic and integrability properties which are dictated by the underlying conformal properties of the theory. We extend the algebraic construction to include a confining potential while preserving the integrability of the mesonic and baryonic bound-state equations.
Date: May 26, 2010
Creator: de Teramond, Guy F.; U., /Costa Rica & Brodsky, Stanley J.
Object Type: Article
System: The UNT Digital Library
Limits on superconductivity-related magnetization in Sr 2RuO 4 and PrOs 4Sb 12 from scanning SQUID microscopy (open access)

Limits on superconductivity-related magnetization in Sr 2RuO 4 and PrOs 4Sb 12 from scanning SQUID microscopy

We present scanning SQUID microscopy data on the superconductors Sr{sub 2}RuO{sub 4} (T{sub c} = 1.5 K) and PrOs{sub 4}Sb{sub 12} (T{sub c} = 1.8 K). In both of these materials, superconductivity-related time-reversal symmetry-breaking fields have been observed by muon spin rotation; our aim was to visualize the structure of these fields. However in neither Sr{sub 2}RuO{sub 4} nor PrOs{sub 4}Sb{sub 12} do we observe spontaneous superconductivity-related magnetization. In Sr{sub 2}RuO{sub 4}, many experimental results have been interpreted on the basis of a p{sub x} {+-} ip{sub y} superconducting order parameter. This order parameter is expected to give spontaneous magnetic induction at sample edges and order parameter domain walls. Supposing large domains, our data restrict domain wall and edge fields to no more than {approx}0.1% and {approx}0.2% of the expected magnitude, respectively. Alternatively, if the magnetization is of the expected order, the typical domain size is limited to {approx}30 nm for random domains, or {approx} 500 nm for periodic domains.
Date: August 26, 2010
Creator: Moler, Kathryn
Object Type: Article
System: The UNT Digital Library
The LINAC Coherent Light Source and Radiological Issues During the Commissioning (open access)

The LINAC Coherent Light Source and Radiological Issues During the Commissioning

The Linac Coherent Light Source (LCLS) at SLAC National Accelerator Laboratory is the world's first X-ray free electron laser (XFEL). Pulses of x-ray laser light from LCLS will be many orders of magnitude brighter and several orders of magnitude shorter than what can be produced by other x-ray sources available in the world. These characteristics will enable frontier new science in many areas. This paper describes the LCLS beam parameters and lay-out. The general radiological issues during commissioning are presented, such as radiation dose rates and integrated doses outside the enclosure. Also, specific radiological issues related to X-ray free electron lasers are discussed. XFEL with high peak power will burn through high-Z materials. The X-ray beam needs to be blocked by stoppers when the downstream areas are occupied. LCLS stoppers feature a piece of boron carbide (B{sub 4}C), 10 mm thick. B{sub 4}C is one of the best materials since it has a low absorption coefficient for X-rays and a high melting temperature. Theoretical calculations indicate that the unfocused fluence of the LCLS XFEL beam should be about one order of magnitude below the damage threshold for bulk B{sub 4}C, for 830 eV FEL radiation. However, these calculations have not …
Date: August 26, 2010
Creator: Mao, X.S.; Leitner, M.Santana & Vollaire, J.
Object Type: Article
System: The UNT Digital Library
LLNL Genomic Assessment: Viral and Bacterial Sequencing Needs for TMTI, Task 1.4.2 Report (open access)

LLNL Genomic Assessment: Viral and Bacterial Sequencing Needs for TMTI, Task 1.4.2 Report

Good progress has been made on both bacterial and viral sequencing by the TMTI centers. While access to appropriate samples is a limiting factor to throughput, excellent progress has been made with respect to getting agreements in place with key sources of relevant materials. Sharing of sequenced genomes funded by TMTI has been extremely limited to date. The April 2010 exercise should force a resolution to this, but additional managerial pressures may be needed to ensure that rapid sharing of TMTI-funded sequencing occurs, regardless of collaborator constraints concerning ultimate publication(s). Policies to permit TMTI-internal rapid sharing of sequenced genomes should be written into all TMTI agreements with collaborators now being negotiated. TMTI needs to establish a Web-based system for tracking samples destined for sequencing. This includes metadata on sample origins and contributor, information on sample shipment/receipt, prioritization by TMTI, assignment to one or more sequencing centers (including possible TMTI-sponsored sequencing at a contributor site), and status history of the sample sequencing effort. While this system could be a component of the AFRL system, it is not part of any current development effort. Policy and standardized procedures are needed to ensure appropriate verification of all TMTI samples prior to the investment …
Date: January 26, 2010
Creator: Slezak, T; Borucki, M; Lam, M; Lenhoff, R & Vitalis, E
Object Type: Report
System: The UNT Digital Library