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Shot Planning and Analysis Tools (open access)

Shot Planning and Analysis Tools

Shot planning and analysis tools (SPLAT) integrate components necessary to help achieve a high over-all operational efficiency of the National Ignition Facility (NIF) by combining near and long-term shot planning, final optics demand and supply loops, target diagnostics planning, and target fabrication requirements. Currently, the SPLAT project is comprised of two primary tool suites for shot planning and optics demand. The shot planning component provides a web-based interface to selecting and building a sequence of proposed shots for the NIF. These shot sequences, or 'lanes' as they are referred to by shot planners, provide for planning both near-term shots in the Facility and long-term 'campaigns' in the months and years to come. The shot planning capabilities integrate with the Configuration Management Tool (CMT) for experiment details and the NIF calendar for availability. Future enhancements will additionally integrate with target diagnostics planning and target fabrication requirements tools. The optics demand component is built upon predictive modelling of maintenance requirements on the final optics as a result of the proposed shots assembled during shot planning. The predictive models integrate energetics from a Laser Performance Operations Model (LPOM), the status of the deployed optics as provided by the online Final Optics Inspection system, …
Date: July 25, 2011
Creator: Casey, A.; Beeler, R.; Conder, A.; Fallejo, R.; Flegel, M.; Hutton, M. et al.
System: The UNT Digital Library
Suppressing Thermal Energy Drift In The LLNL Flash X-Ray Accelerator Using Linear Disk Resistor Stacks (open access)

Suppressing Thermal Energy Drift In The LLNL Flash X-Ray Accelerator Using Linear Disk Resistor Stacks

This paper addresses thermal drift in sodium thiosulfate liquid resistors and their replacement with linear disk resistors from HVR Advanced Power Components. Sodium thiosulfate resistors in the FXR induction linear accelerator application have a temperature coefficient of {approx}1.8%/C. The FXR Marx banks send an 8kJ pulse through eight 524 cm{sup 3} liquid resistors at a repetition rate of up to 1 every 45 seconds. Every pulse increases the temperature of the solution by {approx}0.4 C which produces a 0.7% change in resistance. The typical cooling rate is {approx}0.4 C per minute which results in {approx}0.1% energy drop per pulse during continuous pulsed operations. A radiographic accelerator is extraordinarily sensitive to energy variations. Changes in beam energy produce movement in beam transport, changes in spot size, and large dose variations. If self-heating were the only problem, we could predict the increase in input voltage required to compensate for the energy loss. However, there are other variables that influence the temperature of the resistors such as focus magnet heating, changes in room temperature, changes in cooling water, where the cell is located, etc. Additionally not all of the resistors have equivalent cooling rates and as many as 32 resistors are driven from …
Date: July 19, 2011
Creator: Kreitzer, B R; Houck, T L & Luchterhand, O C
System: The UNT Digital Library
D^* production in deep-inelastic scattering at low Q^2 (open access)

D^* production in deep-inelastic scattering at low Q^2

Inclusive production of D* mesons in deep-inelastic scattering at HERA is studied in the range 5 < Q{sup 2} < 100 GeV{sup 2} of the photon virtuality and 0.02 < y < 0.70 of the inelasticity of the scattering process. The visible range for the D* meson is p{sub T} (D*) > 1.25 GeV and |{eta}(D*)| < 1.8. The data were taken with the H1 detector in the years 2004 to 2007 and correspond to an integrated luminosity of 347 pb{sup -1}. Single and double differential cross sections are measured. The results are compared to QCD predictions.
Date: July 1, 2011
Creator: Jung, Andreas W.
System: The UNT Digital Library
EXPERIMENTAL INVESTIGATION OF NATURAL CONVECTION HEAT TRANSFER OF IONIC LIQUID IN A RECTANGULAR ENCLOSURE HEATED FROM BELOW (open access)

EXPERIMENTAL INVESTIGATION OF NATURAL CONVECTION HEAT TRANSFER OF IONIC LIQUID IN A RECTANGULAR ENCLOSURE HEATED FROM BELOW

This paper presents an experimental study of natural convection heat transfer for an Ionic Liquid. The experiments were performed for 1-butyl-2, 3-dimethylimidazolium bis(trifluoromethylsulfonyl)imide, ([C{sub 4}mmim][NTf{sub 2}]) at a Raleigh number range of 1.26 x 10{sup 7} to 8.3 x 10{sup 7}. In addition to determining the convective heat transfer coefficients, this study also included experimental determination of thermophysical properties of [C{sub 4}mmim][NTf{sub 2}] such as, density, viscosity, heat capacity, and thermal conductivity. The results show that the density of [C{sub 4}mmim][NTf{sub 2}] varies from 1.437-1.396 g/cm{sup 3} within the temperature range of 10-50 C, the thermal conductivity varies from 0.105-0.116 W/m.K between a temperature of 10 to 60 C, the heat capacity varies from 1.015 J/g.K - 1.760 J/g.K within temperature range of 25-340 C and the viscosity varies from 18cp-243cp within temperature range 10-75 C. The results for density, thermal conductivity, heat capacity, and viscosity were in close agreement with the values in the literature. Measured dimensionless Nusselt number was observed to be higher for the ionic liquid than that of DI water. This is expected as Nusselt number is the ratio of heat transfer by convection to conduction and the ionic liquid has lower thermal conductivity (approximately 18%) …
Date: July 18, 2011
Creator: Fox, E.; Visser, A. & Bridges, N.
System: The UNT Digital Library
Structural Design Challenges in Design Certification Applications for New Reactors (open access)

Structural Design Challenges in Design Certification Applications for New Reactors

The licensing framework established by the U.S. Nuclear Regulatory Commission under Title 10 of the Code of Federal Regulations (10 CFR) Part 52, “Licenses, Certifications, and Approvals for Nuclear Power Plants,” provides requirements for standard design certifications (DCs) and combined license (COL) applications. The intent of this process is the early reso- lution of safety issues at the DC application stage. Subsequent COL applications may incorporate a DC by reference. Thus, the COL review will not reconsider safety issues resolved during the DC process. However, a COL application that incorporates a DC by reference must demonstrate that relevant site-specific de- sign parameters are confined within the bounds postulated by the DC, and any departures from the DC need to be justified. This paper provides an overview of structural design chal- lenges encountered in recent DC applications under the 10 CFR Part 52 process, in which the authors have participated as part of the safety review effort.
Date: July 17, 2011
Creator: Miranda, M.; Braverman, J.; Wei, X.; Hofmayer, C. & Xu, J.
System: The UNT Digital Library
MODELING OF LONG-TERM FATE OF MOBILIZED FINES DUE TO DAM-EMBANKMENT INTERFACIAL DISLOCATIONS (open access)

MODELING OF LONG-TERM FATE OF MOBILIZED FINES DUE TO DAM-EMBANKMENT INTERFACIAL DISLOCATIONS

None
Date: July 29, 2011
Creator: Ezzedine, S; Kanarska, Y; Lomov, I; Antoun, T & Glascoe, L
System: The UNT Digital Library
Permanent Magnet Skew Quadrupoles for the Low Emittance LER Lattice of PEP-II (open access)

Permanent Magnet Skew Quadrupoles for the Low Emittance LER Lattice of PEP-II

The vertical emittance of the low energy ring (LER) in the PEP-II B-Factory was reduced by using skew quadrupoles consisting of permanent magnet material. The advantages over electric quadrupoles or rotating existing normal quadrupoles are discussed. To assure a high field quality, a Biot-Savart calculation was used to cancel the natural 12-pole component by using different size poles over a few layers. A magnetic measurement confirmed the high quality of the magnets. After installation and adjusting the original electric 12 skew and 16 normal quadrupoles the emittance contribution from the region close to the interaction point, which was the biggest part in the original design, was considerably reduced. To strengthen the vertical behavior of the LER beam, a low emittance lattice was developed. It lowered the original vertical design emittance from 0.54 nm-rad to 0.034 nm-rad. In order to achieve this, additional skew quadrupoles were required to bring the coupling correction out of the arcs and closer to the detector solenoid in the straight (Fig. 1). It is important, together with low vertical dispersion, that the low vertical emittance is not coupled into the horizontal, which is what we get if the coupling correction continues into the arcs. Further details …
Date: July 5, 2011
Creator: Decker, F. -J.; Anderson, S.; Kharakh, D. & Sullivan, M.
System: The UNT Digital Library
AVOID BECOMING A VICTIM OF COUNTERFEIT ITEMS (open access)

AVOID BECOMING A VICTIM OF COUNTERFEIT ITEMS

In today's globalized economy, we cannot live without imported products. Most people do not realize how thin the safety net of regulation and inspection really is. Less than three percent of imported products receive any form of government inspection prior to sale. Avoid flea markets, street vendors and deep discount stores. The sellers of counterfeit wares know where to market their products. They look for individuals who are hungry for a brand name item but do not want to pay a brand name price for it. The internet provides anonymity to the sellers of counterfeit products. Unlike Europe, U.S. law does not hold internet-marketing organizations, responsible for the quality of the products sold on their websites. These organizations will remove an individual vendor when a sufficient number of complaints are lodged, but they will not take responsibility for the counterfeit products you may have purchased. EBay has a number of counterfeit product guides to help you avoid being a victim of the sellers of these products. Ten percent of all medications taken worldwide are counterfeit. If you do buy medications on-line, be sure that the National Association of Boards of Pharmacy Verified Internet Pharmacy Practice Sites (VIPPS) recommends the pharmacy …
Date: July 13, 2011
Creator: RD, WARRINER
System: The UNT Digital Library
Parallel Index and Query for Large Scale Data Analysis (open access)

Parallel Index and Query for Large Scale Data Analysis

Modern scientific datasets present numerous data management and analysis challenges. State-of-the-art index and query technologies are critical for facilitating interactive exploration of large datasets, but numerous challenges remain in terms of designing a system for process- ing general scientific datasets. The system needs to be able to run on distributed multi-core platforms, efficiently utilize underlying I/O infrastructure, and scale to massive datasets. We present FastQuery, a novel software framework that address these challenges. FastQuery utilizes a state-of-the-art index and query technology (FastBit) and is designed to process mas- sive datasets on modern supercomputing platforms. We apply FastQuery to processing of a massive 50TB dataset generated by a large scale accelerator modeling code. We demonstrate the scalability of the tool to 11,520 cores. Motivated by the scientific need to search for inter- esting particles in this dataset, we use our framework to reduce search time from hours to tens of seconds.
Date: July 18, 2011
Creator: Chou, Jerry; Wu, Kesheng; Ruebel, Oliver; Howison, Mark; Qiang, Ji; Prabhat, et al.
System: The UNT Digital Library
A HIGH REPETITION PLASMA MIRROR FOR STAGED ELECTRON ACCELERATION (open access)

A HIGH REPETITION PLASMA MIRROR FOR STAGED ELECTRON ACCELERATION

In order to build a compact, staged laser plasma accelerator the in-coupling of the laser beam to the different stages represents one of the key issues. To limit the spatial foot print and thus to realize a high overall acceleration gradient, a concept has to be found which realizes this in-coupling within a few centimeters. We present experiments on a tape-drive based plasma mirror which could be used to reflect the focused laser beam into the acceleration stage.
Date: July 22, 2011
Creator: Sokollik, Thomas; Shiraishi, Satomi; Osterhoff, Jens; Evans, Eugene; Gonsalves, Anthony; Nakamura, Kei et al.
System: The UNT Digital Library
Future Roles of Milli-, Micro-, and Nano- Grids (open access)

Future Roles of Milli-, Micro-, and Nano- Grids

Although it has slowed considerably, consumption of electricity continues to grow in developed economies. Further, there are some unknowns which might accelerate this growth, such as electrification of vehicle fleets and geothermal heat pump space and water heating. Most analysts anticipate that distributed energy resources (DER) will provide a large share of the expanded generation capacity required to meet this seemingly inexorably increasing electricity demand. Further, given the urgency of tackling the climate change problem, most of the added assets must be carbonfree renewables or nuclear, end-use efficiency improvements, or highly efficient fossil-fired technologies. In developed economies worldwide, the current power delivery paradigm has been in place for more than a century, i.e. since the emergence of polyphase AC systems around the turn of the last century. A key feature of this structure is that, in principle, universal service is delivered at a consistent level of power quality and reliability (PQR) throughout large regions. This paper describes a future possible structure for the electricity generation and delivery system that leaves the existing high voltage meshed grid paradigm in place, but involves radical reorganization of parts of the distribution network and customer sites. Managing a much more diverse dispersed system poses …
Date: July 1, 2011
Creator: Marnay, Chris; Nordman, Bruce & Lai, Judy
System: The UNT Digital Library
Design of Superconducting Multi-Spoke Cavities for High-Velocity Applications (open access)

Design of Superconducting Multi-Spoke Cavities for High-Velocity Applications

Superconducting spoke cavities have been designed and tested for particle velocities up to {beta}{sub 0} ~ 0.6 and are currently being designed for velocities up to {beta}{sub 0} = 1. We present the electromagnetic designs for two-spoke cavities operating at 325 MHz for {beta}{sub 0} = 0.82 and {beta}{sub 0} = 1.
Date: July 1, 2011
Creator: Hopper, C. S. & Delayen, J. R.
System: The UNT Digital Library
Basin scale assessment of gas hydrate dissociation in response to climate change (open access)

Basin scale assessment of gas hydrate dissociation in response to climate change

Paleooceanographic evidence has been used to postulate that methane from oceanic hydrates may have had a significant role in regulating climate. However, the behavior of contemporary oceanic methane hydrate deposits subjected to rapid temperature changes, like those now occurring in the arctic and those predicted under future climate change scenarios, has only recently been investigated. Field investigations have discovered substantial methane gas plumes exiting the seafloor along the Arctic Ocean margin, and the plumes appear at depths corresponding to the upper limit of a receding gas hydrate stability zone. It has been suggested that these plumes may be the first visible signs of the dissociation of shallow hydrate deposits due to ongoing climate change in the arctic. We simulate the release of methane from oceanic deposits, including the effects of fully-coupled heat transfer, fluid flow, hydrate dissociation, and other thermodynamic processes, for systems representative of segments of the Arctic Ocean margins. The modeling encompasses a range of shallow hydrate deposits from the landward limit of the hydrate stability zone down to water depths beyond the expected range of century-scale temperature changes. We impose temperature changes corresponding to predicted rates of climate change-related ocean warming and examine the possibility of hydrate …
Date: July 1, 2011
Creator: Reagan, M.; Moridis, G.; Elliott, S.; Maltrud, M. & Cameron-Smith, P.
System: The UNT Digital Library
PEMFC MEA and System Design Considerations (open access)

PEMFC MEA and System Design Considerations

Proton exchange membrane fuel cells (PEMFCs) are being developed and sold commercially for multiple near term markets. Ballard Power Systems is focused on the near term markets of backup power, distributed generation, materials handling, and buses. Significant advances have been made in cost and durability of fuel cell products. Improved tolerance to a wide range of system operation and environmental noises will enable increased viability across a broad range of applications. In order to apply the most effective membrane electrode assembly (MEA) design for each market, the system requirements and associated MEA failures must be well understood. The failure modes associated with the electrodes and membrane degradation are discussed with respect to associated system operation and mitigating approaches. A few key system considerations that influence MEA design include expected fuel quality, balance-of-plant materials, time under idle or open circuit operation, and start-up and shut-down conditions.
Date: July 1, 2011
Creator: Knights, Shanna; Bashyam, Rajesh; He, Ping; Lauritzen, Michael; Startek, Cara; Colbow, Vesna et al.
System: The UNT Digital Library
Assessment of Indoor Air Quality Benefits and Energy Costs of Mechanical Ventilation (open access)

Assessment of Indoor Air Quality Benefits and Energy Costs of Mechanical Ventilation

Intake of chemical air pollutants in residences represents an important and substantial health hazard. Sealing homes to reduce air infiltration can save space conditioning energy, but can also increase indoor pollutant concentrations. Mechanical ventilation ensures a minimum amount of outdoor airflow that helps reduce concentrations of indoor emitted pollutants while requiring some energy for fan(s) and thermal conditioning of the added airflow. This work demonstrates a physics based, data driven modeling framework for comparing the costs and benefits of whole-house mechanical ventilation and applied the framework to new California homes. The results indicate that, on a population basis, the health benefits from reduced exposure to indoor pollutants in New California homes are worth the energy costs of adding mechanical ventilation as specified by ASHRAE Standard 62.2.This study determines the health burden for a subset of pollutants in indoor air and the costs and benefits of ASHRAE's mechanical ventilation standard (62.2) for new California homes. Results indicate that, on a population basis, the health benefits of new home mechanical ventilation justify the energy costs.
Date: July 1, 2011
Creator: Logue, J. M.; Price, P. N.; Sherman, M. H. & Singer, B. C.
System: The UNT Digital Library
Ionic liquid pretreatment (open access)

Ionic liquid pretreatment

None
Date: July 20, 2011
Creator: Simmons, Blake; Singh, Seema; Holmes, Bradley & Blanch, Harvey
System: The UNT Digital Library
Quench studies of ILC cavities (open access)

Quench studies of ILC cavities

Quench limits accelerating gradient in SRF cavities to a gradient lower than theoretically expected for superconducting niobium. Identification of the quenching site with thermometry and OST, optical inspection, and replica of the culprit is an ongoing effort at Jefferson Lab aimed at better understanding of this limiting phenomenon. In this contribution we present our finding with several SRF cavities that were limited by quench.
Date: July 1, 2011
Creator: Eremeev, Grigory; Geng, Rongli; Palczewski, Ari & Dai, Jin
System: The UNT Digital Library
X-ray Emission from Electron Betatron Motion in a Laser-Plasma Accelerator (open access)

X-ray Emission from Electron Betatron Motion in a Laser-Plasma Accelerator

Single-shot x-ray spectra from electron bunches produced by a laser-plasma wakefield accelerator (LPA) were measured using a photon-counting single-shot pixelated Silicon-based detector [3], providing for the first time direct spectra without assumptions required by filter based techniques. In addition, the electron bunch source size was measured by imaging a wire target, demonstrating few micron source size and stability. X-rays are generated when trapped electrons oscillate in the focusing field of the wake trailing the driver laser pulse. In addition to improving understanding of bunch emittance and wake structure, this provides a broadband, synchronized femtosecond source of keV x-rays. Electron bunch spectra and divergence were measured simultaneously and preliminary analysis shows correlation between x-ray andelectron spectra. Bremsstrahlung background was managed using shielding and magnetic diversion.
Date: July 19, 2011
Creator: Plateau, Guillaume; Geddes, Cameron; Thorn, Daniel; Matlis, Nicholas; Mittelberger, Daniel; Stoehlker, T et al.
System: The UNT Digital Library
Characterization of Large Grain Nb Ingot Microstructure Using OIM and Laue Methods (open access)

Characterization of Large Grain Nb Ingot Microstructure Using OIM and Laue Methods

Large grain niobium is being examined for fabricating superconducting radiofrequency cavities as an alternative to using rolled sheet with fine grains. It is desirable to know the grain orientations of a niobium ingot slice before fabrication, as this allows heterogeneous strain and surface roughness effects arising from etching to be anticipated. Characterization of grain orientations has been done using orientation imaging microscopy (OIM), which requires destructive extraction of pieces from an ingot slice. Use of a Laue camera allows nondestructive characterization of grain orientations, a process useful for evaluating slices and deformation during the manufacturing process. Five ingot slices from CBMM, Ningxia, and Heraeus are compared. One set of slices was deformed into a half cell and the deformation processes that cause crystal rotations have been investigated and compared with analytical predictions. The five ingot slices are compared in terms of their grain orientations and grain boundary misorientations, indicating no obvious commonalities, which suggests that grain orientations develop randomly during solidification.
Date: July 1, 2011
Creator: D. Kang, D.C. Baars, T.R. Bieler, G. Ciovati, C. Compton, T.L. Grimm, A.A. Kolka
System: The UNT Digital Library
Exploration of Quench Initiation Due to Intentional Geometrical Defects in a High Magnetic Field Region of an SRF Cavity (open access)

Exploration of Quench Initiation Due to Intentional Geometrical Defects in a High Magnetic Field Region of an SRF Cavity

A computer program which was used to simulate and analyze the thermal behaviors of SRF cavities has been developed at Jefferson Lab using C++ code. This code was also used to verify the quench initiation due to geometrical defects in high magnetic field region of SRF cavities. We built a CEBAF single cell cavity with 4 artificial defects near equator, and this cavity has been tested with T-mapping. The preheating behavior and quench initiation analysis of this cavity will be presented here using the computer program.
Date: July 1, 2011
Creator: J. Dai, K. Zhao, G.V. Eremeev, R.L. Geng, A.D. Palczewski; Dai, J.; Palczewski, A. D.; Eremeev, G. V.; Geng, R. L. & Zhao, K.
System: The UNT Digital Library
Chemistry Resolved Kinetic Flow Modeling of TATB Based Explosives (open access)

Chemistry Resolved Kinetic Flow Modeling of TATB Based Explosives

Detonation waves in insensitive, TATB based explosives are believed to have multi-time scale regimes. The initial burn rate of such explosives has a sub-microsecond time scale. However, significant late-time slow release in energy is believed to occur due to diffusion limited growth of carbon. In the intermediate time scale concentrations of product species likely change from being in equilibrium to being kinetic rate controlled. They use the thermo-chemical code CHEETAH linked to an ALE hydrodynamics code to model detonations. They term their model chemistry resolved kinetic flow as CHEETAH tracks the time dependent concentrations of individual species in the detonation wave and calculates EOS values based on the concentrations. A HE-validation suite of model simulations compared to experiments at ambient, hot, and cold temperatures has been developed. They present here a new rate model and comparison with experimental data.
Date: July 21, 2011
Creator: Vitello, P A; Fried, L E; Howard, W M; Levesque, G & Souers, P C
System: The UNT Digital Library
MicroBooNE, A Liquid Argon Time Projection Chamber (LArTPC) Neutrino Experiment (open access)

MicroBooNE, A Liquid Argon Time Projection Chamber (LArTPC) Neutrino Experiment

Liquid Argon time projection chamber (LArTPC) is a promising detector technology for future neutrino experiments. MicroBooNE is a upcoming LArTPC neutrino experiment which will be located on-axis of Booster Neutrino Beam (BNB) at Fermilab, USA. The R&D efforts on this detection method and related neutrino interaction measurements are discussed.
Date: July 1, 2011
Creator: Katori, Teppei
System: The UNT Digital Library
Impact of CO2 geological sequestration on the nucleation of earthquakes (open access)

Impact of CO2 geological sequestration on the nucleation of earthquakes

None
Date: July 15, 2011
Creator: Cappa, F. & Rutqvist, J.
System: The UNT Digital Library
Breaking and Moving Hotspots in a Large Grain Nb Cavity with a Laser Beam (open access)

Breaking and Moving Hotspots in a Large Grain Nb Cavity with a Laser Beam

Magnetic vortices pinned near the inner surface of SRF Nb cavities are a possible source of RF hotspots, frequently observed by temperature mapping of the cavities outer surface at RF surface magnetic fields of about 100 mT. Theoretically, we expect that the thermal gradient provided by a 10 W green laser shining on the inner cavity surface at the RF hotspot locations can move pinned vortices to different pinning locations. The experimental apparatus to send the beam onto the inner surface of a photoinjector-type large-grain Nb cavity is described. Preliminary results on the changes in thermal maps observed after applying the laser heating are also reported.
Date: July 25, 2011
Creator: Ciovati, G.; Cheng, G.; Flood, R. J.; Jordan, K.; Kneisel, P.; Morrone, M. L. et al.
System: The UNT Digital Library