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Spent fuel sabotage test program, characterization of aerosol dispersal : technical review and analysis supplement

Lindgren, Eric; Durbin, S.

This project seeks to provide vital data required to assess the consequences of a terrorist attack on a spent fuel transportation cask. One such attack scenario involves the use of conical shaped charges (CSC), which are capable of damaging a spent fuel transportation cask. In the event of such an attack, the amount of radioactivity that may be released as respirable aerosols is not known with great certainty. Research to date has focused on measuring the aerosol release from single short surrogate fuel rodlets subjected to attack by a small CSC device in various aerosol chamber designs. The last series of three experiments tested surrogate fuel rodlets made with depleted uranium oxide ceramic pellets in a specially designed double chamber aerosol containment apparatus. This robust testing apparatus was designed to prevent any radioactive release and allow high level radioactive waste disposal of the entire apparatus following testing of actual spent fuel rodlets as proposed. DOE and Sandia reviews of the project to date identified a number of issues. The purpose of this supplemental report is to address and document the DOE review comments and to resolve the issues identified in the Sandia technical review.

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Algebraic connectivity and graph robustness

Feddema, John T.

Recent papers have used Fiedler's definition of algebraic connectivity to show that network robustness, as measured by node-connectivity and edge-connectivity, can be increased by increasing the algebraic connectivity of the network. By the definition of algebraic connectivity, the second smallest eigenvalue of the graph Laplacian is a lower bound on the node-connectivity. In this paper we show that for circular random lattice graphs and mesh graphs algebraic connectivity is a conservative lower bound, and that increases in algebraic connectivity actually correspond to a decrease in node-connectivity. This means that the networks are actually less robust with respect to node-connectivity as the algebraic connectivity increases. However, an increase in algebraic connectivity seems to correlate well with a decrease in the characteristic path length of these networks - which would result in quicker communication through the network. Applications of these results are then discussed for perimeter security.

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Needed improvements in the development of systemic corrective actions

Campisi, John A.

There are indications that corrective actions, as implemented at Sandia National Laboratories are not fully adequate. Review of independent audits spanning multiple years provides evidence of recurring issues within the same or similar operations and programs. Several external audits have directly called into question the ability Sandia's assessment and evaluation processes to prevent recurrence. Examples of repeated findings include lockout/tagout programs, local exhaust ventilation controls and radiological controls. Recurrence clearly shows that there are underlying systemic factors that are not being adequately addressed by corrective actions stemming from causal analyses. Information suggests that improvements in the conduct of causal analyses and, more importantly, in the development of subsequent corrective actions are warranted. Current methodolgies include Management Oversight Risk Tree, developed in the early 1970s and Systemic Factors Analysis. Recommendations for improvements include review of other causal analysis systems, training, improved formality of operations, improved documentation, and a corporate method that uses truly systemic solutions. This report was written some years ago and is being published now to form the foundation for current, follow-on reports being developed. Some outdated material is recognized but is retained for report completeness.

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Measurements of the operating characteristics of a 1064 nm pumped KTP RISTRA OPO

Armstrong, Darrell J.

Measurements of the operating characteristics of a 1064 nm pumped potassium titanyl phosphte (KTP) optical parametric oscillator (OPO) were carried out at the Electro Optics Systems Laboratory of Georgia Tech Research Institute (GTRI). The OPO was developed by Sandia National Laboratories and employs a nonplanar image-rotating geometry that is known by the acronym RISTRA, denoting Rotated Image Singly-Resonant Twisted RectAngle. The OPO was configured for pumping by the 1064 nm fundamental wavelength of a Q-switched Nd:YAG laser to generate a signal wavelength at 1627 nm and idler wavelength at 3074.8 nm. GTRI will be incorporate the OPO into a multi-wavelength lidar platform called the Integrated Atmospheric Characterization System (IACS). Prior to completion of the system design for the IACS platform, personnel at GTRI carried out a series of risk reduction experiments to measure the operating characteristics of the OPO. Sandia's role in this effort included technical assistance with numerical modeling of OPO performance, selection of nonlinear optical crystals, specification of cavity-mirror dielectric coatings, selection of vendors for optical components, and advice concerning integration of the RISTRA OPO into the IACS platform. This report describes results of the risk reduction measurements and it also provides some background information on the operating characteristics of RISTRA OPO's but is not intended to be a tutorial. A working knowledge of pulsed solid-state lasers, laser cavity modes, laser beam quality and beam propagation, and three-wave mixing in nonlinear crystals, is useful.

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Risk-informed separation distances for hydrogen refueling stations

International Journal of Hydrogen Energy

Lachance, Jeffrey L.

As part of the US Department of Energy Hydrogen, Fuel Cells & Infrastructure Technologies Program, Sandia National Laboratories is developing the technical basis for assessing the safety of hydrogen-based systems for use in the development/modification of relevant codes and standards. This work includes quantitative risk assessments (QRA) of hydrogen facilities. The QRAs are used to identify and quantify scenarios for the unintended release of hydrogen and thus help identify the code requirements that would reduce the risk at hydrogen facilities to acceptable levels. This paper describes an application of QRA methods to help establish one key code requirement: the minimum separation distances between a hydrogen refueling station and other facilities and the public at large. An example application of the risk-informed approach has been performed to illustrate its utility and to identify key parameters that can influence the resulting selection of separation distances. © 2009 International Association for Hydrogen Energy.

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Impurity production and acceleration in CTIX

Journal of Nuclear Materials

Buchenauer, D.; Clift, W.M.; Klauser, R.; Horton, R.D.; Howard, S.J.; Brockington, S.J.; Evans, R.W.; Hwang, D.Q.

The Compact Toroid Injection Experiment (CTIX) produces a high density, high velocity hydrogen plasma that maintains its configuration in free space on a MHD resistive time scale. In order to study the production and acceleration of impurities in the injector, several sets of silicon collector probes were exposed to spheromak-like CT's exiting the accelerator. Elemental analysis by Auger Electron Spectroscopy indicated the presence of O, Al, Fe, and Cu in films up to 200 Å thickness (1000 CT interactions). Using a smaller number of CT interactions (10-20), implantation of Fe and Cu was measured by Auger depth profiling. The amount of impurities was found to increase with accelerating voltage and number of CT interactions while use of a solenoidal field reduced the amount. Comparison of the implanted Fe and Cu with TRIM simulations indicated that the impurities were traveling more slowly than the hydrogen CT. © 2009 Elsevier B.V.

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Time Resolved Ion Beam Induced Current measurements on MOS capacitors using a cyclotron microbeam

Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms

Vizkelethy, G.; Onoda, S.; Hirao, T.; Ohshima, T.; Kamiya, T.

As overlayers on electronic devices become progressively thicker, radiation effects microscopy using traditional microbeams (with ion energies up to a few tens of MeVs) is becoming less and less viable. To penetrate to the sensitive regions of these devices, much higher energies, several hundreds of MeVs are necessary. These high energies are available only from cyclotrons. A nuclear microprobe has been developed on the AVF cyclotron of the Takasaki Ion Accelerators for Advanced Radiation Applications (TIARA) facility. In this paper we will present the first results using 260 MeV Ne and 520 MeV Ar microbeams to perform Time Resolved Ion Beam Induced Current (TRIBIC) measurements on Metal-Oxide-Semiconductor (MOS) capacitors. The results will be compared to data taken with a traditional 15 MeV O microbeam. © 2009 Elsevier B.V.

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Phosphors' lifetime measurement employing the Time Between Photons method

Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms

Rossi, P.; Doyle, B.L.; Brice, D.K.; Vizkelethy, G.; McDaniel, F.D.; Branson, J.V.

The Time Between Photons theory (hereafter TBP) is applied to the evaluation of the lifetime of phosphors employed in the Ion Photon Emission Microscope (IPEM). IPEM allows Radiation Effects Microscopy (REM) without focused ion beams and appears to be the best tool for the radiation hardness assessment of modern integrated circuit at cyclotron energies. IPEM determines the impact point of a single ion onto the sample by measuring the light spot produced on a thin phosphor layer placed on the sample surface. The spot is imaged by an optical microscope and projected at high magnification onto a Position Sensitive Detector (PSD). Phosphors, when excited by an ion, emit photons with a particular lifetime, which is important to evaluate. We measured the statistical distribution of the Time Between consecutive detected Photons (TBP) for several phosphors and have been able to link it to their lifetime employing a theory that is derived in this paper. The single-photon signals are provided by the IPEM-PSD, or faster photomultipliers when high-speed materials had to be assessed. © 2009 Elsevier B.V. All rights reserved.

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Indications of an inward pinch in the inner SOL of DIII-D from 13C deposition experiments

Journal of Nuclear Materials

Elder, J.D.; McLean, A.G.; Stangeby, P.C.; Allen, S.L.; Boedo, J.A.; Bray, B.D.; Brooks, N.H.; Fenstermacher, M.E.; Groth, M.; Leonard, A.W.; Rudakov, D.L.; Wampler, W.R.; Watkins, J.G.; West, W.P.; Whyte, D.G.

13C methane puffing experiments were conducted on DIII-D in both L- and ELMy H-mode conditions. The puffing was toroidally symmetric into the crown of a series of well-characterized lower single-null discharges. The hydrocarbon breakup, carbon transport and deposition were modeled using the OEDGE interpretive code. Three separate hypotheses were tested using OEDGE to try to reproduce the experimental deposition: Radial variation of fast parallel flow, erosion of the puffed 13C deposited in the divertor, and a pinch in the inner scrape off layer (SOL) towards the separatrix. A fast parallel flow was imposed for all hypotheses. The magnitude and the distribution of the 13C deposition resulting from each hypothesis are compared. A fast parallel flow in the SOL toward the inner divertor combined with a pinch/drift of 10-30 m/s in the inner SOL towards the separatrix roughly reproduces the deposition in both the L- and H-mode experiments. © 2009 Elsevier B.V.

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Evaporated lithium surface coatings in NSTX

Journal of Nuclear Materials

Kugel, H.W.; Mansfield, D.; Maingi, R.; Bell, M.G.; Bell, R.E.; Allain, J.P.; Gates, D.; Gerhardt, S.; Kaita, R.; Kallman, J.; Kaye, S.; LeBlanc, B.; Majeski, R.; Menard, J.; Mueller, D.; Ono, M.; Paul, S.; Raman, R.; Roquemore, A.L.; Ross, P.W.; Sabbagh, S.; Schneider, H.; Skinner, C.H.; Soukhanovskii, V.; Stevenson, T.; Timberlake, J.; Wampler, W.R.; Wilgren, J.; Zakharov, L.

Two lithium evaporators were used to evaporate more than 100 g of lithium on to the NSTX lower divertor region. Prior to each discharge, the evaporators were withdrawn behind shutters, where they also remained during the subsequent HeGDC applied for periods up to 9.5 min. After the HeGDC, the shutters were opened and the LITERs were reinserted to deposit lithium on the lower divertor target for 10 min, at rates of 10-70 mg/min, prior to the next discharge. The major improvements in plasma performance from these lithium depositions include: (1) plasma density reduction as a result of lithium deposition; (2) suppression of ELMs; (3) improvement of energy confinement in a low-triangularity shape; (4) improvement in plasma performance for standard, high-triangularity discharges; (5) reduction of the required HeGDC time between discharges; (6) increased pedestal electron and ion temperature; (7) reduced SOL plasma density; and (8) reduced edge neutral density. © 2009 Elsevier B.V.

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THz emission from coherent plasmons in InAs nanowires

Proceedings of SPIE - The International Society for Optical Engineering

Seletskiy, D.V.; Hasselbeck, M.P.; Sheik-Bahae, M.; Cederberg, Jeffrey G.; Talin, Albert A.

We report the first observation of coherent plasmon emission of THz radiation from arrays of semiconductor nanowires. The THz signal strength from InAs nanowires is comparable to a planar substrate, indicating the nanowires are highly efficient emitters. This is explained by the preferential orientation of plasma motion to the wire surface, which overcomes radiation trapping by total-internal reflection. Using a bulk Drude model, we identify the average donor density and mobility in the nanowires in a non-contact manner. Contact IV transconductance measurements provide order of magnitude agreement with values obtained from the THz spectra. © 2009 SPIE.

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Simulation of blast-induced early-time intracranial wave physics leading to traumatic brain injury

Journal of Biomechanical Engineering

Taylor, Paul A.; Ford, Corey C.

The objective of this modeling and simulation study was to establish the role of stress wave interactions in the genesis of traumatic brain injury (TBI) from exposure to explosive blast. A high resolution (1 mm3 voxels) five material model of the human head was created by segmentation of color cryosections from the Visible Human Female data set. Tissue material properties were assigned from literature values. The model was inserted into the shock physics wave code, CTH, and subjected to a simulated blast wave of 1.3 MPa (13 bars) peak pressure from anterior, posterior, and lateral directions. Three-dimensional plots of maximum pressure, volumetric tension, and deviatoric (shear) stress demonstrated significant differences related to the incident blast geometry. In particular, the calculations revealed focal brain regions of elevated pressure and deviatoric stress within the first 2 ms of blast exposure. Calculated maximum levels of 15 KPa deviatoric, 3.3 MPa pressure, and 0.8 MPa volumetric tension were observed before the onset of significant head accelerations. Over a 2 ms time course, the head model moved only 1 mm in response to the blast loading. Doubling the blast strength changed the resulting intracranial stress magnitudes but not their distribution. We conclude that stress localization, due to early-time wave interactions, may contribute to the development of multifocal axonal injury underlying TBI. We propose that a contribution to traumatic brain injury from blast exposure, and most likely blunt impact, can occur on a time scale shorter than previous model predictions and before the onset of linear or rotational accelerations traditionally associated with the development of TBI. Copyright © 2009 by ASME.

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The impact of specific surface area on the retention of deuterium in carbon fiber composite materials

Fusion Engineering and Design

Kolasinski, Robert; Umstadter, K.R.; Sharpe, J.P.; Causey, Rion A.; Pawelko, R.J.; Whaley, Josh A.; Buchenauer, D.A.; Shimada, M.

In this study, the PISCES-A linear plasma instrument has been used to characterize retention in several carbon fiber composites in order to better understand the factors which lead to elevated retention levels in these materials. The PISCES instrument is capable of subjecting materials to intense fluxes (up to 1022 m-2 s-1) of low energy (150 eV) D+ ions, producing conditions similar to those encountered by plasma facing components in a fusion reactor. In this investigation, three CFCs (fabricated with different manufacturing processes) are compared with the N11 composite used in the Tore Supra reactor. The specific surface areas for these materials were within the range of 0.14-0.55 m2/g. The plasma bombardment conditions were adjusted to provide doses on the order of 1025-1026 m-2 at a sample temperature of 200 °C. After removal from PISCES-A, the amount of D retained in the sample surface was determined via thermal desorption spectroscopy. The measured retention showed a strong correlation with the type of material used and the corresponding BET surface area. By using a CFC with a lower internal porosity, one could expect a reduction in retention by a factor of 5 or more. © 2008 Elsevier B.V.

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Kauai Island Utility Cooperative Energy Storage Study

Murray, Aaron T.

Sandia National Laboratories performed an assessment of the benefits of energy storage for the Kauai Island Utility Cooperative. This report documents the methodology and results of this study from a generation and production-side benefits perspective only. The KIUC energy storage study focused on the economic impact of using energy storage to shave the system peak, which reduces generator run time and consequently reduces fuel and operation and maintenance (O&M) costs. It was determined that a 16-MWh energy storage system would suit KIUC's needs, taking into account the size of the 13 individual generation units in the KIUC system and a system peak of 78 MW. The analysis shows that an energy storage system substantially reduces the run time of Units D1, D2, D3, and D5 - the four smallest and oldest diesel generators at the Port Allen generating plant. The availability of stored energy also evens the diurnal variability of the remaining generation units during the off- and on-peak periods. However, the net economic benefit is insufficient to justify a load-leveling type of energy storage system at this time. While the presence of storage helps reduce the run time of the smaller and older units, the economic dispatch changes and the largest most efficient unit in the KIUC system, the 27.5-MW steam-injected combustion turbine at Kapaia, is run for extra hours to provide the recharge energy for the storage system. The economic benefits of the storage is significantly reduced because the charging energy for the storage is derived from the same fuel source as the peak generation source it displaces. This situation would be substantially different if there were a renewable energy source available to charge the storage. Especially, if there is a wind generation resource introduced in the KIUC system, there may be a potential of capturing the load-leveling benefits as well as using the storage to dampen the dynamic instability that the wind generation could introduce into the KIUC grid. General Electric is presently conducting such a study and results of this study will be available in the near future. Another study conducted by Electric Power Systems, Inc. (EPS) in May 2006 took a broader approach to determine the causes of KIUC system outages. This study concluded that energy storage with batteries will provide stability benefits and possibly eliminate the load shedding while also providing positive voltage control. Due to the lack of fuel diversity in the KIUC generation mix, SNL recommends that KIUC continue its efforts to quantify the dynamic benefits of storage. The value of the dynamic benefits, especially as an enabler of renewable generation such as wind energy, may be far greater than the production cost benefits alone. A combination of these benefits may provide KIUC sufficient positive economic and operational benefits to implement an energy storage project that will contribute to the overall enhancement of the KIUC system.

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Photoneutron effects on pulse reactor kinetics for the Annular Core Research Reactor (ACRR)

Parma, Edward J.

The Annular Core Research Reactor (ACRR) is a swimming-pool type pulsed reactor that maintains an epithermal neutron flux and a nine-inch diameter central dry cavity. One of its uses is neutron and gamma-ray irradiation damage studies on electronic components under transient reactor power conditions. In analyzing the experimental results, careful attention must be paid to the kinetics associated with the reactor to ensure that the transient behavior of the electronic device is understood. Since the ACRR fuel maintains a substantial amount of beryllium, copious quantities of photoneutrons are produced that can significantly alter the expected behavior of the reactor power, especially following a reactor pulse. In order to understand these photoneutron effects on the reactor kinetics, the KIFLE transient reactor-analysis code was modified to include the photoneutron groups associated with the beryllium. The time-dependent behavior of the reactor power was analyzed for small and large pulses, assuming several initial conditions including following several pulses during the day, and following a long steady-state power run. The results indicate that, for these types of initial conditions, the photoneutron contribution to the reactor pulse energy can have a few to tens of percent effect.

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SAR impulse response with residual chirps

Doerry, Armin W.

A Linear Frequency-Modulated (LFM) chirp is a function with unit amplitude and quadratic phase characteristic. In a focused Synthetic Aperture Radar (SAR) image, a residual chirp is undesired for targets of interest, as it coarsens the manifested resolution. However, for undesired spurious signals, a residual chirp is often advantageous because it spreads the energy and thereby diminishes its peak value. In either case, a good understanding of the effects of a residual LFM chirp on a SAR Impulse Response (IPR) is required to facilitate system analysis and design. This report presents an analysis of the effects of a residual chirp on the IPR. As reference, there is a rich body of publications on various aspects of LFM chirps. A quick search reveals a plethora of articles, going back to the early 1950s. We mention here purely as trivia one of the earlier analysis papers on this waveform by Klauder, et al.

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Sandia National Laboratories/New Mexico existing environmental analyses bounding environmental test facilities

May, Rodney A.

This report identifies current environmental operating parameters for the various test and support facilities at SNL/NM. The intent of this report is solely to provide the limits which bound the facilities' operations. Understanding environmental limits is important to maximizing the capabilities and working within the existing constraints of each facility, and supports the decision-making process in meeting customer requests, cost and schedule planning, modifications to processes, future commitments, and use of resources. Working within environmental limits ensures that mission objectives will be met in a manner that protects human health and the environment. It should be noted that, in addition to adhering to the established limits, other approvals and permits may be required for specific projects.

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Implementation of equilibrium aqueous speciation and solubility (EQ3 type) calculations into Cantera for electrolyte solutions

Moffat, Harry K.; Jove-Colon, Carlos F.

In this report, we summarize our work on developing a production level capability for modeling brine thermodynamic properties using the open-source code Cantera. This implementation into Cantera allows for the application of chemical thermodynamics to describe the interactions between a solid and an electrolyte solution at chemical equilibrium. The formulations to evaluate the thermodynamic properties of electrolytes are based on Pitzer's model to calculate molality-based activity coefficients using a real equation-of-state (EoS) for water. In addition, the thermodynamic properties of solutes at elevated temperature and pressures are computed using the revised Helgeson-Kirkham-Flowers (HKF) EoS for ionic and neutral aqueous species. The thermodynamic data parameters for the Pitzer formulation and HKF EoS are from the thermodynamic database compilation developed for the Yucca Mountain Project (YMP) used with the computer code EQ3/6. We describe the adopted equations and their implementation within Cantera and also provide several validated examples relevant to the calculations of extensive properties of electrolyte solutions.

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IceT users' guide and reference

Moreland, Kenneth D.

The Image Composition Engine for Tiles (IceT) is a high-performance sort-last parallel rendering library. In addition to providing accelerated rendering for a standard display, IceT provides the unique ability to generate images for tiled displays. The overall resolution of the display may be several times larger than any viewport that may be rendered by a single machine. This document is an overview of the user interface to IceT.

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LIVA: A Data Reduction Program for Line-imaging ORVIS Measurements

Ao, Tommy

LIVA (Line-Imaging Velocimetry Analysis) is a program for reducing data of a line-imaging optically recording velocity interferometer system (ORVIS) diagnostic. LIVA uses the Fourier transform method to extract phase information from recorded streak camera images. The extracted phase shift is used to infer target velocity as a function of space and time. The program can be run in any current version of MATLAB (2008a or later) or as a Windows XP executable.

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A very high sensitivity RF pulse profile measurement system

Proposed for publication in IEEE Transactions on Instrumentation and Measurement.

Lai, Jesse L.

A technique for characterizing the pulse profile of a radio-frequency (RF) amplifier over a very wide power range under fast-pulsing conditions is presented. A pulse-modulated transmitter is used to drive a device under test (DUT) with a phase-coded signal that allows for an increased measurement range beyond standard techniques. A measurement receiver that samples points on the output pulse power profile and performs the necessary signal processing and coherent pulse integration, improving the detectability of low-power signals, is described. The measurement technique is applied to two sample amplifiers under fast-pulsing conditions with a pulsewidth of 250 ns at 3-GHz carrier frequency. A full measurement range of greater than 160 dB is achieved, extending the current state of the art in pulse-profiling techniques.

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Exploring diagnostic capabilities for application to new photovoltaic technologies

Quintana, Enrico C.; Quintana, Michael A.; Rolfe, Kevin D.; Thompson, Kyle

Explosive growth in photovoltaic markets has fueled new creative approaches that promise to cut costs and improve reliability of system components. However, market demands require rapid development of these new and innovative technologies in order to compete with more established products and capture market share. Often times diagnostics that assist in R&D do not exist or have not been applied due to the innovative nature of the proposed products. Some diagnostics such as IR imaging, electroluminescence, light IV, dark IV, x-rays, and ultrasound have been employed in the past and continue to serve in development of new products, however, innovative products with new materials, unique geometries, and previously unused manufacturing processes require additional or improved test capabilities. This fast-track product development cycle requires diagnostic capabilities to provide the information that confirms the integrity of manufacturing techniques and provides the feedback that can spawn confidence in process control, reliability and performance. This paper explores the use of digital radiography and computed tomography (CT) with other diagnostics to support photovoltaic R&D and manufacturing applications.

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Compaction localization and constitutive behavior of weak porous sandstone

Dewers, Thomas; Holcomb, David J.

A combined experimental and constitutive modeling program for weak porous sandstone deformation is described. A series of axisymmetric compression tests were performed over a range of mean stresses to study dilatational, compactional and transitional regimes. Experimental results were used both to derive constitutive parameters for testing localization theory and to parameterize a poroelastic-plastic model. Observed strain localization, imaged syn-deformationally using acoustic emissions, includes high- and low-angle shear and low angle compactional features or 'bands'. Isotropic elastic moduli measured via unloading loops show a progressive degradation pre-failure as decreasing functions of work-conjugate plastic strains and increasing functions of stress magnitude. The degradation pathway is unique for samples which underwent localization versus those that underwent spatially pervasive pore collapse. Total shear and volume strains are partitioned into elastic and plastic portions including the ''coupling'' strain associated with modulus degradation. Plastic strain calculated with and without the coupling term is compared with regard to localization predictions. Both coupled and uncoupled cases predict high angle shear bands for uniaxial and low mean stress conditions on the dilatational side of the yield surface. Uncoupled predictions show progressively lower angle shear bands approaching the transitional regime (stress conditions approaching the 'cap' surface). When elastic-plastic coupling is accounted for, compaction bands are predicted for the transitional regime, as are observed in the experiments. Finite element modeling efforts are described using a 3-invariant, mixed-hardening, continuous yield surface, elasto-plasticity model that includes several features important for porous sandstone constitutive behavior and observed experimentally, including non-associativity, nonlinear elasticity, elastic-plastic coupling, and kinematic hardening. Modeled deformational behavior attending stress paths relevant for several reservoir production scenarios are described.

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Development of a HT seismic downhole tool

Chavira, David C.; Henfling, Joseph A.; Greving, Jeffrey J.

Enhanced Geothermal Systems (EGS) require the stimulation of the drilled well, likely through hydraulic fracturing. Whether fracturing of the rock occurs by shear destabilization of natural fractures or by extensional failure of weaker zones, control of the fracture process will be required to create the flow paths necessary for effective heat mining. As such, microseismic monitoring provides one method for real-time mapping of the fractures created during the hydraulic fracturing process. This monitoring is necessary to help assess stimulation effectiveness and provide the information necessary to properly create the reservoir. In addition, reservoir monitoring of the microseismic activity can provide information on reservoir performance and evolution over time. To our knowledge, no seismic tool exists that will operate above 125 C for the long monitoring durations that may be necessary. Replacing failed tools is costly and introduces potential errors such as depth variance, etc. Sandia has designed a high temperature seismic tool for long-term deployment in geothermal applications. It is capable of detecting microseismic events and operating continuously at temperatures up to 240 C. This project includes the design and fabrication of two High Temperature (HT) seismic tools that will have the capability to operate in both temporary and long-term monitoring modes. To ensure the developed tool meets industry requirements for high sampling rates (>2ksps) and high resolution (24-bit Analog-to-Digital Converter) two electronic designs will be implemented. One electronic design will utilize newly developed 200 C electronic components. The other design will use qualified Silicon-on-Insulator (SOI) devices and will have a continuous operating temperature of 240 C.

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A total risk assessment methodology for security assessment

Wyss, Gregory D.; Otero, Consuelo J.; Pless, Daniel; Rhea, Ronald E.; Kaplan, Paul G.

Sandia National Laboratories performed a two-year Laboratory Directed Research and Development project to develop a new collaborative risk assessment method to enable decision makers to fully consider the interrelationships between threat, vulnerability, and consequence. A five-step Total Risk Assessment Methodology was developed to enable interdisciplinary collaborative risk assessment by experts from these disciplines. The objective of this process is promote effective risk management by enabling analysts to identify scenarios that are simultaneously achievable by an adversary, desirable to the adversary, and of concern to the system owner or to society. The basic steps are risk identification, collaborative scenario refinement and evaluation, scenario cohort identification and risk ranking, threat chain mitigation analysis, and residual risk assessment. The method is highly iterative, especially with regard to scenario refinement and evaluation. The Total Risk Assessment Methodology includes objective consideration of relative attack likelihood instead of subjective expert judgment. The 'probability of attack' is not computed, but the relative likelihood for each scenario is assessed through identifying and analyzing scenario cohort groups, which are groups of scenarios with comparable qualities to the scenario being analyzed at both this and other targets. Scenarios for the target under consideration and other targets are placed into cohort groups under an established ranking process that reflects the following three factors: known targeting, achievable consequences, and the resources required for an adversary to have a high likelihood of success. The development of these target cohort groups implements, mathematically, the idea that adversaries are actively choosing among possible attack scenarios and avoiding scenarios that would be significantly suboptimal to their objectives. An adversary who can choose among only a few comparable targets and scenarios (a small comparable target cohort group) is more likely to choose to attack the specific target under analysis because he perceives it to be a relatively unique attack opportunity. The opposite is also true. Thus, total risk is related to the number of targets that exist in each scenario cohort group. This paper describes the Total Risk Assessment Methodology and illustrates it through an example.

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High-g shock test results of Tadiran TLM-1530MP cells

O'Malley, Patrick D.

In April of 2009, testing was done of a high-g instrumentation device that utilized Tadiran TLM-1530MP cells as a power source. As a result of that testing, it was determined that those cells exhibit failure more often when shocked in the axial direction. No failures over many tests where found when the cells were shocked laterally. Moreover, when shocked laterally, the cells exhibited no observable degradation in performance. We looked at the failed cells via non-destructive x-ray analysis to determine what internal structures failed.

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A super-sampled projection method for level-set construction in fluid-solid interaction problems

Sandia journal manuscript; Not yet accepted for publication

Tipton, David G.

Here, this paper considers the issues central to fast level-set construction for the general treatement of moving interfaces in coupled fluid-solid interaction problems where the Lagrangian solid experiences large bulk motion. The central idea is based on a super-sampled L2 projection, that in conjunction with a Lagrangian interface position, permits rapid identification of the solid interface in the fluid mesh and enables the imposition of boundary conditions for the fluid. A series of convergence studies are presented in terms of numerical quadrature and mesh refinement to illustrate the effectiveness of the super-sampled projection on unstructured grids. The extraction of the interface location based on distance functions is compared to the super-sampled projection method. Finally, it is shown that the extraction of an interface location based on a zero level-set converges as O(h) when compared to the exact interface location - suggesting that the availability of a Lagrangian interface description is always preferred.

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Sandia National Laboratories, California Air Quality Program annual report

Gardizi, Leslee P.

The annual program report provides detailed information about all aspects of the SNL/CA Air Quality Program. It functions as supporting documentation to the SNL/CA Environmental Management System Program Manual. The program report describes the activities undertaken during the past year, and activities planned in future years to implement the Air Quality Program, one of six programs that supports environmental management at SNL/CA.

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Wall pressure exerted by hydrogenation of sodium aluminum hydride

Zimmerman, Mark D.; Perras, Yon E.

Wall pressure exerted by the bulk expansion of a sodium aluminum hydride bed was measured as a function of hydrogen content. A custom apparatus was designed and loaded with sodium alanates at densities of 1.0, 1.1, and 1.16 g/cc. Four complete cycles were performed to identify variations in measured pressure. Results indicated poor correlation between exerted pressure and hydrogen capacity of the sodium alanate beds. Mechanical pressure due to the hydrogenation of sodium alanates does not influence full-scale system designs as it falls within common design factors of safety. Gas pressure gradients within the porous solid were identified and may limit reaction rates, especially for high aspect ratio beds.

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High reliability low jitter 80 kV pulse generator

Proposed for publication in Physical Review: Special Topics on Accelerators and Beams.

Savage, Mark E.; Stoltzfus, Brian

Switching can be considered to be the essence of pulsed power. Time accurate switch/trigger systems with low inductance are useful in many applications. This article describes a unique switch geometry coupled with a low-inductance capacitive energy store. The system provides a fast-rising high voltage pulse into a low impedance load. It can be challenging to generate high voltage (more than 50 kilovolts) into impedances less than 10 {Omega}, from a low voltage control signal with a fast rise time and high temporal accuracy. The required power amplification is large, and is usually accomplished with multiple stages. The multiple stages can adversely affect the temporal accuracy and the reliability of the system. In the present application, a highly reliable and low jitter trigger generator was required for the Z pulsed-power facility [M. E. Savage, L. F. Bennett, D. E. Bliss, W. T. Clark, R. S. Coats,J. M. Elizondo, K. R. LeChien, H. C. Harjes, J. M. Lehr, J. E. Maenchen, D. H. McDaniel, M. F. Pasik, T. D. Pointon, A. C. Owen, D. B. Seidel, D. L. Smith, B. S. Stoltzfus, K.W. Struve, W.A. Stygar, L.K. Warne, and J. R. Woodworth, 2007 IEEE Pulsed Power Conference, Albuquerque, NM (IEEE, Piscataway, NJ, 2007), p. 979]. The large investment in each Z experiment demands low prefire probability and low jitter simultaneously. The system described here is based on a 100 kV DC-charged high-pressure spark gap, triggered with an ultraviolet laser. The system uses a single optical path for simultaneously triggering two parallel switches, allowing lower inductance and electrode erosion with a simple optical system. Performance of the system includes 6 ns output rise time into 5.6 {Omega}, 550 ps one-sigma jitter measured from the 5 V trigger to the high voltage output, and misfire probability less than 10{sup -4}. The design of the system and some key measurements will be shown in the paper. We will discuss the design goals related to high reliability and low jitter. While reliability is usually important, and is coupled with jitter, reliability is seldom given more than a qualitative analysis (if any at all). We will show how reliability of the system was calculated, and results of a jitter-reliability tradeoff study. We will describe the behavior of sulfur hexafluoride as the insulating gas in the mildly nonuniform field geometry at pressures of 300 to 500 kPa. We will show the resistance of the arc channels, and show the performance comparisons with normal two-channel operation, and single channel operation.

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Shotgun protein sequencing

Heffelfinger, Grant S.

A novel experimental and computational technique based on multiple enzymatic digestion of a protein or protein mixture that reconstructs protein sequences from sequences of overlapping peptides is described in this SAND report. This approach, analogous to shotgun sequencing of DNA, is to be used to sequence alternative spliced proteins, to identify post-translational modifications, and to sequence genetically engineered proteins.

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Ultra-thin multilayer capacitors

Renk, Timothy J.

The fabrication of ultra-thin lanthanum-doped lead zirconium titanate (PLZT) multilayer ceramic capacitors (MLCCs) using a high-power pulsed ion beam was studied. The deposition experiments were conducted on the RHEPP-1 facility at Sandia National Laboratories. The goal of this work was to increase the energy density of ceramic capacitors through the formation of a multilayer device with excellent materials properties, dielectric constant, and standoff voltage. For successful device construction, there are a number of challenging requirements including achieving correct stoichiometric and crystallographic composition of the deposited PLZT, as well as the creation of a defect free homogenous film. This report details some success in satisfying these requirements, although 900 C temperatures were necessary for PLZT perovskite phase formation. These temperatures were applied to a previously deposited multi-layer film which was then post-annealed to this temperature. The film exhibited mechanical distress attributable to differences in the coefficient of thermal expansion (CTE) of the various layers. This caused significant defects in the deposited films that led to shorts across devices. A follow-on single layer deposition without post-anneal produced smooth layers with good interface behavior, but without the perovskite phase formation. These issues will need to be addressed in order for ion beam deposited MLCCs to become a viable technology. It is possible that future in-situ heating during deposition may address both the CTE issue, and result in lowered processing temperatures, which in turn could raise the probability of successful MLCC formation.

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Electric utility transmission and distribution upgrade deferral benefits from modular electricity storage : a study for the DOE Energy Storage Systems Program

Eyer, James M.

The work documented in this report was undertaken as part of an ongoing investigation of innovative and potentially attractive value propositions for electricity storage by the United States Department of Energy (DOE) and Sandia National Laboratories (SNL) Electricity Storage Systems (ESS) Program. This study characterizes one especially attractive value proposition for modular electricity storage (MES): electric utility transmission and distribution (T&D) upgrade deferral. The T&D deferral benefit is characterized in detail. Also presented is a generalized framework for estimating the benefit. Other important and complementary (to T&D deferral) elements of possible value propositions involving MES are also characterized.

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Leveraging U.S. nuclear weapons policy to advance U.S. nonproliferation goals : implications of major theories of international relations

Walter, Andrew

National policymakers are currently considering a dilemma of critical importance to the continued security of the United States: how can U.S. nuclear weapons policies be leveraged to benefit U.S. nuclear nonproliferation goals in the near-term, without sacrificing U.S. national security? In its role supporting U.S. nuclear weapons policy, Sandia National Laboratories has a responsibility to provide objective technical advice to support policy deliberations on this question. However, to best fulfill this duty Sandia must have a broader understanding of the context of the problem. To help develop this understanding, this paper analyzes the two predominant analytical perspectives of international relations theory to explore their prescriptions for how nuclear weapons and nonproliferation policies interact. As lenses with which to view and make sense of the world, theories of international relations must play a crucial role in framing the trade-offs at the intersection of the nuclear weapons and nonproliferation policy domains. An analysis of what these theories suggest as courses of action to leverage nuclear weapons policies to benefit nonproliferation goals is then offered, with particular emphasis on where the policy prescriptions resulting from the respective theories align to offer near-term policy changes with broad theoretical support. These policy prescriptions are then compared to the 2001 Nuclear Posture Review to understand what the theories indicate policymakers may have gotten right in their dealing with the nuclear dilemma, and where they may have gone wrong. Finally, a brief international relations research agenda is proposed to help address the dilemma between nuclear deterrence and nuclear nonproliferation policies, with particular emphasis on how such an agenda can best support the needs of the policy community and a potential 'all things nuclear' policy deliberation and decision-support framework.

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Oxalate co-precipitation synthesis of calcium zirconate and calcium titanate powders

Tuttle, Bruce; Sipola, Diana L.; Garino, Terry J.; Mahoney, Patrick M.; Rodriguez, Mark A.; Voigt, James A.

Fine powders of calcium zirconate (CaZrO{sub 3}, CZ) and calcium titanate (CaTiO{sub 3}, CT) were synthesized using a nonaqueous oxalate co-precipitation route from Ca(NO{sub 3}){sub 2}{center_dot}4 H{sub 2}O and group(IV) n-butoxides (Ti(OBu{sup n}){sub 4} or Zr(OBu{sup n}){sub 4}). Several reaction conditions and batch sizes (2-35 g) were explored to determine their influence on final particle size, morphology, and phase. Characterization of the as-prepared oxalate precursors, oven dried oxalate precursors (60-90 C), and calcined powders (635-900 C) were analyzed with TGA/DTA, XRD, TEM, and SEM. Densification and sintering studies on pressed CZ pellets at 1375 and 1400 C were also performed. Through the developed oxalate co-precipitation route, densification temperatures for CZ were lowered by 125 C from the 1500 C firing temperature required for conventional mixed oxide powders. Low field electrical tests of the CZ pellets indicated excellent dielectric properties with dielectric constants of {approx}30 and a dissipation factor of 0.0004 were measured at 1 kHz.

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Evaluation of lead/carbon devices for utility applications : a study for the DOE Energy Storage Program

Walmet, Paula S.

This report describes the results of a three-phase project that evaluated lead-based energy storage technologies for utility-scale applications and developed carbon materials to improve the performance of lead-based energy storage technologies. In Phase I, lead/carbon asymmetric capacitors were compared to other technologies that used the same or similar materials. At the end of Phase I (in 2005) it was found that lead/carbon asymmetric capacitors were not yet fully developed and optimized (cost/performance) to be a viable option for utility-scale applications. It was, however, determined that adding carbon to the negative electrode of a standard lead-acid battery showed promise for performance improvements that could be beneficial for use in utility-scale applications. In Phase II various carbon types were developed and evaluated in lead-acid batteries. Overall it was found that mesoporous activated carbon at low loadings and graphite at high loadings gave the best cycle performance in shallow PSoC cycling. Phase III studied cost/performance benefits for a specific utility application (frequency regulation) and the full details of this analysis are included as an appendix to this report.

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Microphotonic thermal detectors and imagers

Proceedings of SPIE - The International Society for Optical Engineering

Shaw, Michael; Rakich, Peter T.; Lentine, Anthony L.; Nielson, Gregory N.; Wright, Jeremy B.; Zortman, William; Mccormick, Frederick B.

We present the theory of operation along with detailed device designs and initial experimental results of a new class of uncooled thermal detectors. The detectors, termed microphotonic thermal detectors, are based on the thermo-optic effect in high quality factor (Q) micrometer-scale optical resonators. Microphotonic thermal detectors do not suffer from Johnson noise, do not require metallic connections to the sensing element, do not suffer from charge trapping effects, and have responsivities orders of magnitude larger than microbolometer-based thermal detectors. For these reasons, microphotonic thermal detectors have the potential to reach thermal phonon noise limited performance. © 2009 SPIE.

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Combined photodarkening and thermal bleaching measurement of an ytterbium-doped fiber

Proceedings of SPIE - The International Society for Optical Engineering

Ponsoda, Joan J.Montiel; Söderlund, Mikko; Koplow, Jeffrey; Koponen, Joona; Iho, Aarni; Honkanen, Seppo

A combined photodarkening and thermal bleaching measurement of a large-mode-area (LMA) ytterbium-doped fiber (YDF) is presented. Photodarkened YDF sample is recovered to pre-photodarkened state by thermal annealing. As a result, this approach enables repeated measurements with the same sample and therefore eliminates uncertainties related to changing of the sample (such as sample length and splice losses). Additionally, our approach potentially improves the accuracy and repeatability of the photodarkening rate measurement, and also allows automation of the measurement procedure. © 2009 SPIE.

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Results 75201–75400 of 99,299
Results 75201–75400 of 99,299