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Sample records for breakdown structure cbs

  1. CBS | OpenEI Community

    Open Energy Info (EERE)

    CBS Home Kch's picture Submitted by Kch(24) Member 15 July, 2014 - 07:07 MHK Cost Breakdown Structure Draft CBS current energy GMREC LCOE levelized cost of energy marine energy MHK...

  2. MHK Cost Breakdown Structure Draft | OpenEI Community

    Open Energy Info (EERE)

    MHK Cost Breakdown Structure Draft Home > Groups > Water Power Forum Kch's picture Submitted by Kch(24) Member 15 July, 2014 - 07:07 CBS current energy GMREC LCOE levelized cost of...

  3. Module 2- Work Breakdown Structure

    Broader source: Energy.gov [DOE]

    This module defines and illustrates the Work Breakdown Structure (WBS), WBS dictionary, Organizational Breakdown Structure (OBS) and Responsibility Assignment Matrix (RAM).

  4. Cost Codes and the Work Breakdown Structure

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1997-03-28

    The chapter discusses the purpose of the work breakdown structure (WBS) and code of account (COA) cost code system, shows the purpose and fundamental structure of both the WBS and the cost code system, and explains the interface between the two systems.

  5. Structural basis for substrate activation and regulation by cystathionine beta-synthase (CBS) domains in cystathionine [beta]-synthase

    SciTech Connect (OSTI)

    Koutmos, Markos; Kabil, Omer; Smith, Janet L.; Banerjee, Ruma

    2011-08-17

    The catalytic potential for H{sub 2}S biogenesis and homocysteine clearance converge at the active site of cystathionine {beta}-synthase (CBS), a pyridoxal phosphate-dependent enzyme. CBS catalyzes {beta}-replacement reactions of either serine or cysteine by homocysteine to give cystathionine and water or H{sub 2}S, respectively. In this study, high-resolution structures of the full-length enzyme from Drosophila in which a carbanion (1.70 {angstrom}) and an aminoacrylate intermediate (1.55 {angstrom}) have been captured are reported. Electrostatic stabilization of the zwitterionic carbanion intermediate is afforded by the close positioning of an active site lysine residue that is initially used for Schiff base formation in the internal aldimine and later as a general base. Additional stabilizing interactions between active site residues and the catalytic intermediates are observed. Furthermore, the structure of the regulatory 'energy-sensing' CBS domains, named after this protein, suggests a mechanism for allosteric activation by S-adenosylmethionine.

  6. AVLIS Production Plant work breakdown structure and Dictionary

    SciTech Connect (OSTI)

    Not Available

    1984-11-15

    The work breakdown structure has been prepared for the AVLIS Production Plant to define, organize, and identify the work efforts and is summarized in Fig. 1-1 for the top three project levels. The work breakdown structure itself is intended to be the primary organizational tool of the AVLIS Production Plant and is consistent with the overall AVLIS Program Work Breakdown Structure. It is designed to provide a framework for definition and accounting of all of the elements that are required for the eventual design, procurement, and construction of the AVLIS Production Plant. During the present phase of the AVLIS Project, the conceptual engineering phase, the work breakdown structure is intended to be the master structure and project organizer of documents, designs, and cost estimates. As the master project organizer, the key role of the work breakdown structure is to provide the mechanism for developing completeness in AVLIS cost estimates and design development of all hardware and systems. The work breakdown structure provides the framework for tracking, on a one-to-one basis, the component design criteria, systems requirements, design concepts, design drawings, performance projections, and conceptual cost estimates. It also serves as a vehicle for contract reporting. 12 figures, 2 tables.

  7. PHENIX Work Breakdown Structure. Cost and schedule review copy

    SciTech Connect (OSTI)

    Not Available

    1994-02-01

    The Work Breakdown Structure (WBS) Book begins with this Overview section, which contains the high-level summary cost estimate, the cost profile, and the global construction schedule. The summary cost estimate shows the total US cost and the cost in terms of PHENIX construction funds for building the PHENIX detector. All costs in the WBS book are shown in FY 1993 dollars. Also shown are the institutional and foreign contributions, the level of pre-operations funding, and the cost of deferred items. Pie charts are presented at PHENIX WBS level 1 and 2 that show this information. The PHENIX construction funds are shown broken down to PHENIX WBS level 3 items per fiscal year, and the resulting profile is compared to the RHIC target profile. An accumulated difference of the two profiles is also shown. The PHENIX global construction schedule is presented at the end of the Overview section. Following the Overview are sections for each subsystem. Each subsystem section begins with a summary cost estimate, cost profile, and critical path. The total level 3 cost is broken down into fixed costs (M&S), engineering costs (EDIA) and labor costs. Costs are further broken down in terms of PHENIX construction funds, institutional and foreign contributions, pre-operations funding, and deferred items. Also shown is the contingency at level 3 and the level 4 breakdown of the total cost. The cost profile in fiscal years is shown at level 3. The subsystem summaries are followed by the full cost estimate and schedule sheets for that subsystem. These detailed sheets are typically carried down to level 7 or 8. The cost estimate shows Total, M&S, EDIA, and Labor breakdowns, as well as contingency, for each WBS entry.

  8. Cost and schedule control systems criteria for contract performance measurement: work breakdown structure guide

    SciTech Connect (OSTI)

    Not Available

    1981-10-01

    This document provides guidance on development and use of the Work Breakdown Structure (WBS) technique. It describes the types of work breakdown structures, their preparation, and their effective use for organizing, planning, and controlling projects and contracts managed by the Department of Energy (DOE). The WBS technique is the preferred management tool for identifying and defining work. It provides an ordered framework for planning and controlling the work efforts to be performed in achieving technical objectives and for summarizing data, and the quantitative and narrative reports used for monitoring cost, schedule and technical performance. A WBS is developed for first identifying the major end items or systems to be produced, followed by their successive subdivision into increasingly detailed and manageable subsidiary products. Most of these subsidiary products are the direct result of work, while others are simply the aggregation of selected products into a logical set for management control purposes. In either case, detailed tasks are eventually identified for each product on the WBS at the level where work will be performed. As a minimum, these detailed tasks or work packages identify the product, describe the effort to be performed, identify the resources to be applied, specify the budget and schedule constraints, and the technical requirements, and identify the organizational element responsible for work accomplishment.

  9. CBS Job Openings | The Ames Laboratory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    CBS Job Openings Associate Scientist The Ames Laboratory is seeking candidates for a Principal Investigator (PI)-track research position, at the level of Associate Scientist. This person will conduct research within the Division of Chemical and Biological Sciences as part of a catalysis program funded by the DOE, Office of Science, Basic Energy Sciences. The overarching goal of this effort is to create catalytic materials with the best properties of homogeneous and heterogeneous catalysts for

  10. Effect of surface produced secondary electrons on the sheath structure induced by high-power microwave window breakdown

    SciTech Connect (OSTI)

    Cheng Guoxin; Liu Lie

    2011-03-15

    Dielectric window breakdown, whose mechanism is not thoroughly understood, is a major factor of limiting the transmission and radiation of high-power microwave on the order of 1 GW. In this paper, a one-dimensional fluid-like sheath model is developed to investigate the sheath structures formed at different gas pressures. The dominant processes during the surface flashover are isolated by this model. In vacuum, electron multipactor is self-sustained by secondary electron emission, a positive space-charge potential is formed on the dielectric surface. With increasing gas pressure, electron-neutral ionization prevails against secondary electron emission. The multipactor effect is suppressed by the shielding of plasma electrons. This leads to the sheath potential changing gradually from a positive space-charge potential to a negative space-charge potential. For argon gas pressure lower than 14 Torr, the sheath is space charge limited. A potential minimum could be formed in front of the dielectric which traps secondary electrons emitted from the wall. With the higher argon gas pressure, the number density of ions becomes comparable to that of electrons, all surface produced electrons are accelerated toward the presheath region. Therefore, the normal sheath is formed and the resulting surface flashover on the dielectric surface becomes rf-driven volumetric breakdown.

  11. OpenEI Community - LCOE

    Open Energy Info (EERE)

    Cost Breakdown Structure Draft http:en.openei.orgcommunitydocumentmhk-cost-breakdown-structure-draft

    The generalized Cost Breakdown Structure (CBS) for marine and...

  12. An efficient extrapolation to the (T)/CBS limit

    SciTech Connect (OSTI)

    Ranasinghe, Duminda S.; Barnes, Ericka C.

    2014-05-14

    We extrapolate to the perturbative triples (T)/complete basis set (CBS) limit using double ? basis sets without polarization functions (Wesleyan-1-Triples-2? or Wes1T-2Z) and triple ? basis sets with a single level of polarization functions (Wesleyan-1-Triples-3? or Wes1T-3Z). These basis sets were optimized for 102 species representing the first two rows of the Periodic Table. The species include the entire set of neutral atoms, positive and negative atomic ions, as well as several homonuclear diatomic molecules, hydrides, rare gas dimers, polar molecules, such as oxides and fluorides, and a few transition states. The extrapolated Wes1T-(2,3)Z triples energies agree with (T)/CBS benchmarks to within 0.65 mE{sub h}, while the rms deviations of comparable model chemistries W1, CBS-APNO, and CBS-QB3 for the same test set are 0.23 mE{sub h}, 2.37 mE{sub h}, and 5.80 mE{sub h}, respectively. The Wes1T-(2,3)Z triples calculation time for the largest hydrocarbon in the G2/97 test set, C{sub 6}H{sub 5}Me{sup +}, is reduced by a factor of 25 when compared to W1. The cost-effectiveness of the Wes1T-(2,3)Z extrapolation validates the usefulness of the Wes1T-2Z and Wes1T-3Z basis sets which are now available for a more efficient extrapolation of the (T) component of any composite model chemistry.

  13. [Fundamental studies of passivity and passivity breakdown

    SciTech Connect (OSTI)

    Macdonald, D.D.

    1993-07-01

    We developed and experimentally tested physical models for growth and breakdown of passive films on metal surfaces. These models are ``point defect models,`` in which the growth and breakdown are described in terms of movement of anion and cation vacancies. The work during the past 5 years resulted in: theory of growth and breakdown of passive films, theory of corrosion-resistant alloys, electronic structure of passive films, and estimation of damage functions for energy systems. Proposals are give for the five ongoing tasks. 10 figs.

  14. RF breakdown experiments at SLAC

    SciTech Connect (OSTI)

    Laurent, L. [University of California Davis, Davis, California 95616 (United States); Vlieks, A.; Pearson, C.; Caryotakis, G.; Luhmann, N.C. [Stanford Linear Accelerator Center, Menlo Park, California 94025 (United States)

    1999-05-01

    RF breakdown is a critical issue in the conditioning of klystrons, accelerator sections, and rf components for the next linear collider (NLC), as well as other high gradient accelerators and high power microwave sources. SLAC is conducting a series of experiments using an X-band traveling wave ring to characterize the processes and trigger mechanisms associated with rf breakdown. The goal of the research is to identify materials, processes, and manufacturing methods that will increase the breakdown threshold and minimize the time required for conditioning. {copyright} {ital 1999 American Institute of Physics.}

  15. Vortex breakdown in closed containers with polygonal cross sections

    SciTech Connect (OSTI)

    Naumov, I. V. Dvoynishnikov, S. V.; Kabardin, I. K.; Tsoy, M. A.

    2015-12-15

    The vortex breakdown bubble in the confined flow generated by a rotating lid in closed containers with polygonal cross sections was analysed both experimentally and numerically for the height/radius aspect ratio equal to 2. The stagnation point locations of the breakdown bubble emergence and the corresponding Reynolds number were determined experimentally and in addition computed numerically by STAR-CCM+ CFD software for square, pentagonal, hexagonal, and octagonal cross section configurations. The flow pattern and the velocity were observed and measured by combining the seeding particle visualization and the temporal accuracy of laser Doppler anemometry. The vortex breakdown size and position on the container axis were determined for Reynolds numbers, ranging from 1450 to 2400. The obtained results were compared with the flow structure in the closed container of cubical and cylindrical configurations. It is shown that the measured evolution of steady vortex breakdown is in close agreement with the numerical results.

  16. RF BREAKDOWN STUDIES USING PRESSURIZED CAVITIES

    SciTech Connect (OSTI)

    Johnson, Rolland

    2014-09-21

    Many present and future particle accelerators are limited by the maximum electric gradient and peak surface fields that can be realized in RF cavities. Despite considerable effort, a comprehensive theory of RF breakdown has not been achieved and mitigation techniques to improve practical maximum accelerating gradients have had only limited success. Part of the problem is that RF breakdown in an evacuated cavity involves a complex mixture of effects, which include the geometry, metallurgy, and surface preparation of the accelerating structures and the make-up and pressure of the residual gas in which plasmas form. Studies showed that high gradients can be achieved quickly in 805 MHz RF cavities pressurized with dense hydrogen gas, as needed for muon cooling channels, without the need for long conditioning times, even in the presence of strong external magnetic fields. This positive result was expected because the dense gas can practically eliminate dark currents and multipacting. In this project we used this high pressure technique to suppress effects of residual vacuum and geometry that are found in evacuated cavities in order to isolate and study the role of the metallic surfaces in RF cavity breakdown as a function of magnetic field, frequency, and surface preparation. One of the interesting and useful outcomes of this project was the unanticipated collaborations with LANL and Fermilab that led to new insights as to the operation of evacuated normal-conducting RF cavities in high external magnetic fields. Other accomplishments included: (1) RF breakdown experiments to test the effects of SF6 dopant in H2 and He gases with Sn, Al, and Cu electrodes were carried out in an 805 MHz cavity and compared to calculations and computer simulations. The heavy corrosion caused by the SF6 components led to the suggestion that a small admixture of oxygen, instead of SF6, to the hydrogen would allow the same advantages without the corrosion in a practical muon beam line. (2) A

  17. Fundamental studies of passivity and passivity breakdown. Final report, [September 1993--September 1994

    SciTech Connect (OSTI)

    Macdonald, D.D.; Urquidi-Macdonald, M.

    1994-02-21

    Purpose is to understand the mechanisms for growth and breakdown of passive films on metal and alloy surfaces in aqueous medium; a secondary goal is to devise methods for predicting localized corrosion damage in industrial systems. Tasks currently being studied are: formation of bilayer structures in passive films on metals and alloys; passivity breakdown on solid vs. liquid gallium; roles of alloying elements in passivity breakdown; electrochemical impedance spectroscopy of passive films; electronic structure of passive oxide films; photoelectrochemical impedance spectroscopy of passive films; and kinetics of localized attack.

  18. Comparative genomics of citric-acid producing Aspergillus niger ATCC 1015 versus enzyme-producing CBS 513.88

    SciTech Connect (OSTI)

    Grigoriev, Igor V.; Baker, Scott E.; Andersen, Mikael R.; Salazar, Margarita P.; Schaap, Peter J.; Vondervoot, Peter J.I. van de; Culley, David; Thykaer, Jette; Frisvad, Jens C.; Nielsen, Kristen F.; Albang, Richard; Albermann, Kaj; Berka, Randy M.; Braus, Gerhard H.; Braus-Stromeyer, Susanna A.; Corrochano, Luis M.; Dai, Ziyu; Dijck, Piet W.M. van; Hofmann, Gerald; Lasure, Linda L.; Magnusson, Jon K.; Meijer, Susan L.; Nielsen, Jakob B.; Nielsen, Michael L.; Ooyen, Albert J.J. van; Panther, Kathyrn S.; Pel, Herman J.; Poulsen, Lars; Samson, Rob A.; Stam, Hen; Tsang, Adrian; Brink, Johannes M. van den; Atkins, Alex; Aerts, Andrea; Shapiro, Harris; Pangilinan, Jasmyn; Salamov, Asaf; Lou, Yigong; Lindquist, Erika; Lucas, Susan; Grimwood, Jane; Kubicek, Christian P.; Martinez, Diego; Peij, Noel N.M.E. van; Roubos, Johannes A.; Nielsen, Jens

    2011-04-28

    The filamentous fungus Aspergillus niger exhibits great diversity in its phenotype. It is found globally, both as marine and terrestrial strains, produces both organic acids and hydrolytic enzymes in high amounts, and some isolates exhibit pathogenicity. Although the genome of an industrial enzyme-producing A. niger strain (CBS 513.88) has already been sequenced, the versatility and diversity of this species compels additional exploration. We therefore undertook whole genome sequencing of the acidogenic A. niger wild type strain (ATCC 1015), and produced a genome sequence of very high quality. Only 15 gaps are present in the sequence and half the telomeric regions have been elucidated. Moreover, sequence information from ATCC 1015 was utilized to improve the genome sequence of CBS 513.88. Chromosome-level comparisons uncovered several genome rearrangements, deletions, a clear case of strain-specific horizontal gene transfer, and identification of 0.8 megabase of novel sequence. Single nucleotide polymorphisms per kilobase (SNPs/kb) between the two strains were found to be exceptionally high (average: 7.8, maximum: 160 SNPs/kb). High variation within the species was confirmed with exo-metabolite profiling and phylogenetics. Detailed lists of alleles were generated, and genotypic differences were observed to accumulate in metabolic pathways essential to acid production and protein synthesis. A transcriptome analysis revealed up-regulation of the electron transport chain, specifically the alternative oxidative pathway in ATCC 1015, while CBS 513.88 showed significant up-regulation of genes relevant to glucoamylase A production, such as tRNA-synthases and protein transporters. Our results and datasets from this integrative systems biology analysis resulted in a snapshot of fungal evolution and will support further optimization of cell factories based on filamentous fungi.[Supplemental materials (10 figures, three text documents and 16 tables) have been made available

  19. RF breakdown of 805 MHz cavities in strong magnetic fields

    SciTech Connect (OSTI)

    Bowring, D.; Stratakis, D.; Kochemirovskiy, A.; Leonova, M.; Moretti, A.; Palmer, M.; Peterson, D.; Yonehara, K.; Freemire, B.; Lane, P.; Torun, Y.; Haase, A.

    2015-05-03

    Ionization cooling of intense muon beams requires the operation of high-gradient, normal-conducting RF structures in the presence of strong magnetic fields. We have measured the breakdown rate in several RF cavities operating at several frequencies. Cavities operating within solenoidal magnetic fields B > 0.25 T show an increased RF breakdown rate at lower gradients compared with similar operation when B = 0 T. Ultimately, this breakdown behavior limits the maximum safe operating gradient of the cavity. Beyond ionization cooling, this issue affects the design of photoinjectors and klystrons, among other applications. We have built an 805 MHz pillbox-type RF cavity to serve as an experimental testbed for this phenomenon. This cavity is designed to study the problem of RF breakdown in strong magnetic fields using various cavity materials and surface treatments, and with precise control over sources of systematic error. We present results from tests in which the cavity was run with all copper surfaces in a variety of magnetic fields.

  20. Breakdown properties of irradiated MOS capacitors

    SciTech Connect (OSTI)

    Paccagnella, A.; Candelori, A.; Milani, A.; Formigoni, E.; Ghidini, G.; Drera, D.; Pellizzer, F.; Fuochi, P.G.; Lavale, M.

    1996-12-01

    The authors have studied the effects of ionizing and non-ionizing radiation on the breakdown properties of different types of MOS capacitors, with thick (200 nm) and thin (down to 8 nm) oxides. In general, no large variations of the average breakdown field, time-to-breakdown at constant voltage, or charge-to-breakdown at constant voltage, or charge-to-breakdown values have been observed after high dose irradiation (20 Mrad(Si) 9 MeV electrons on thin and thick oxides, 17(Si) Mrad Co{sup 60} gamma and 10{sup 14} neutrons/cm{sup 2} only on thick oxides). However, some modifications of the cumulative failure distributions have been observed in few of the oxides tested.

  1. Mitigating Breakdown in High Energy Density Perovskite Polymer...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Mitigating Breakdown in High Energy Density Perovskite Polymer Nanocomposite Capacitors Mitigating Breakdown in High Energy Density Perovskite Polymer Nanocomposite Capacitors 2012 ...

  2. Kondo Breakdown in Topological Kondo Insulators (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    Kondo Breakdown in Topological Kondo Insulators Prev Next Title: Kondo Breakdown in Topological Kondo Insulators Authors: Alexandrov, Victor ; Coleman, Piers ; Erten, Onur ...

  3. Asymmetric Bimodal Accelerator Cavity for Raising rf Breakdown Thresholds

    SciTech Connect (OSTI)

    Kuzikov, S. V.; Kazakov, S. Yu.; Jiang, Y.; Hirshfield, J. L.

    2010-05-28

    We consider an axisymmetric microwave cavity for an accelerator structure whose eigenfrequency for its second lowest TM-like axisymmetric mode is twice that of the lowest such mode, and for which the fields are asymmetric along its axis. In this cavity, the peak amplitude of the rf electric field that points into either longitudinal face can be smaller than the peak field which points out. Computations show that a structure using such cavities might support an accelerating gradient about 47% greater than that for a structure using similar single-mode cavities, without an increase in breakdown probability.

  4. Spark gap with low breakdown voltage jitter

    DOE Patents [OSTI]

    Rohwein, Gerald J.; Roose, Lars D.

    1996-01-01

    Novel spark gap devices and electrodes are disclosed. The novel spark gap devices and electrodes are suitable for use in a variety of spark gap device applications. The shape of the electrodes gives rise to local field enhancements and reduces breakdown voltage jitter. Breakdown voltage jitter of approximately 5% has been measured in spark gaps according the invention. Novel electrode geometries and materials are disclosed.

  5. Spark gap with low breakdown voltage jitter

    DOE Patents [OSTI]

    Rohwein, G.J.; Roose, L.D.

    1996-04-23

    Novel spark gap devices and electrodes are disclosed. The novel spark gap devices and electrodes are suitable for use in a variety of spark gap device applications. The shape of the electrodes gives rise to local field enhancements and reduces breakdown voltage jitter. Breakdown voltage jitter of approximately 5% has been measured in spark gaps according the invention. Novel electrode geometries and materials are disclosed. 13 figs.

  6. Surface breakdown igniter for mercury arc devices

    DOE Patents [OSTI]

    Bayless, John R.

    1977-01-01

    Surface breakdown igniter comprises a semiconductor of medium resistivity which has the arc device cathode as one electrode and has an igniter anode electrode so that when voltage is applied between the electrodes a spark is generated when electrical breakdown occurs over the surface of the semiconductor. The geometry of the igniter anode and cathode electrodes causes the igniter discharge to be forced away from the semiconductor surface.

  7. Humidity effects on wire insulation breakdown strength.

    SciTech Connect (OSTI)

    Appelhans, Leah

    2013-08-01

    Methods for the testing of the dielectric breakdown strength of insulation on metal wires under variable humidity conditions were developed. Two methods, an ASTM method and the twisted pair method, were compared to determine if the twisted pair method could be used for determination of breakdown strength under variable humidity conditions. It was concluded that, although there were small differences in outcomes between the two testing methods, the non-standard method (twisted pair) would be appropriate to use for further testing of the effects of humidity on breakdown performance. The dielectric breakdown strength of 34G copper wire insulated with double layer Poly-Thermaleze/Polyamide-imide insulation was measured using the twisted pair method under a variety of relative humidity (RH) conditions and exposure times. Humidity at 50% RH and below was not found to affect the dielectric breakdown strength. At 80% RH the dielectric breakdown strength was significantly diminished. No effect for exposure time up to 140 hours was observed at 50 or 80%RH.

  8. Can surface cracks and unipolar arcs explain breakdown and gradient limits?

    SciTech Connect (OSTI)

    Insepov, Zeke; Norem, Jim

    2013-01-15

    The authors argue that the physics of unipolar arcs and surface cracks can help understand rf breakdown and vacuum arc data. They outline a model of the basic mechanisms involved in breakdown and explore how the physics of unipolar arcs and cracks can simplify the picture of breakdown and gradient limits in accelerators, tokamaks as well as laser ablation, micrometeorites, and other applications. Cracks are commonly seen in SEM images of arc damage and they are produced as the liquid metal cools. They can produce the required field enhancements to explain field emission data and can produce mechanical failure of the surface that would trigger breakdown events. Unipolar arcs can produce currents sufficient to short out rf structures, and can cause the sort of damage seen in SEM images. They should be unstable, and possibly self-quenching, as seen in optical fluctuations and surface damage. The authors describe some details and consider the predictions of this simple model.

  9. Prevention of breakdown behind railgun projectiles

    DOE Patents [OSTI]

    Hawke, R.S.

    1992-09-01

    An electromagnetic railgun accelerator system, for accelerating projectiles by a plasma arc, introduces a breakdown inhibiting gas into the railgun chamber behind the accelerating projectile. The breakdown inhibiting gas, which absorbs electrons, is a halide or a halide compound such as fluorine or SF[sub 6]. The gas is introduced between the railgun rails after the projectile has passed through inlets in the rails or the projectile; by coating the rails or the projectile with a material which releases the gas after the projectile passes over it; by fabricating the rails or the projectile or insulators out of a material which releases the gas into the portions of the chamber through which the projectile has travelled. The projectile may have a cavity at its rear to control the release of ablation products. 12 figs.

  10. Prevention of breakdown behind railgun projectiles

    DOE Patents [OSTI]

    Hawke, R.S.

    1992-10-13

    An electromagnetic railgun accelerator system, for accelerating projectiles by a plasma arc, introduces a breakdown inhibiting gas into the railgun chamber behind the accelerating projectile. The breakdown inhibiting gas, which absorbs electrons, is a halide or a halide compound such as fluorine or SF[sub 6]. The gas is introduced between the railgun rails after the projectile has passed through inlets in the rails or the projectile; by coating the rails or the projectile with a material which releases the gas after the projectile passes over it; by fabricating the rails or the projectile or insulators out of a material which releases the gas into the portions of the chamber through which the projectile has travelled. The projectile may have a cavity at its rear to control the release of ablation products. 12 figs.

  11. Prevention of breakdown behind railgun projectiles

    DOE Patents [OSTI]

    Hawke, Ronald S. (Livermore, CA)

    1992-01-01

    An electromagnetic railgun accelerator system, for accelerating projectiles (14, 15, 114, 214, 314, 414) by a plasma arc (3), introduces a breakdown inhibiting gas into the railgun chamber (26) behind the accelerating projectile (14). The breakdown inhibiting gas, which absorbs electrons, is a halide or a halide compound such as fluorine or SF.sub.6. The gas is introduced between the railgun rails (12) after the projectile (14) has passed through inlets (16) in the rails (12) or the projectile (114); by coating the rails (12) or the projectile (15) with a material (28) which releases the gas after the projectile (14) passes over it; by fabricating the rails (12) or the projectile (15) or insulators out of a material which releases the gas into the portions of the chamber (26) through which the projectile has travelled. The projectile (214, 314, 414) may have a cavity (232, 332, 432) at its rear to control the release of ablation products (4).

  12. Prevention of breakdown behind railgun projectiles

    DOE Patents [OSTI]

    Hawke, Ronald S. (Livermore, CA)

    1992-01-01

    An electromagnetic railgun accelerator system, for accelerating projectiles (14, 15, 114, 214, 314, 444) by a plasma arc (3), introduces a breakdown inhibiting gas into the railgun chamber (26) behind the accelerating projectile (14). The breakdown inhibiting gas, which absorbs electrons, is a halide or a halide compound such as fluorine or SF.sub.6. The gas is introduced between the railgun rails (12) after the projectile (14) has passed through inlets (16) in the rails (12) or the projectile (114); by coating the rails (12) or the projectile (15) with a material (28) which releases the gas after the projectile (14 ) passes over it; by fabricating the rails (12) or the projectile (15) or insulators out of a material which releases the gas into the portions of the chamber (26) through which the projectile has travelled. The projectile (214, 314, 414) may have a cavity (232, 332, 432) at its rear to control the release of ablation products (4).

  13. Breakdown of Angular Momentum Selection Rules in High Pressure Optical Pumping Experiments

    SciTech Connect (OSTI)

    Lancor, B.; Wyllie, R.; Walker, T. G.; Babcock, E.

    2010-08-20

    We present measurements, by using two complementary methods, of the breakdown of atomic angular momentum selection rules in He-broadened Rb vapor. Atomic dark states are rendered weakly absorbing due to fine-structure mixing during Rb-He collisions. The effect substantially increases the photon demand for optical pumping of dense vapors.

  14. COST BREAKDOWN AWARD NO: START DATE: EXPIRATION DATE: FISCAL YEAR BREAKDOWN OF FUNDS

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    COST BREAKDOWN AWARD NO: START DATE: EXPIRATION DATE: FISCAL YEAR BREAKDOWN OF FUNDS ELEMENTS FY FY FY FY FY TOTAL Direct Labor Overhead Materials Supplies Travel Other Direct Costs Subcontractors Total Direct Costs G&A Expense Total All Costs DOE Share* Awardee Share* Overhead Rate G&A Rate 1. The cost elements indicated are provided as an example only. Your firm should indicate the costs elements you have used on your invoices. 2. You should indicate the cost incurred for each of your

  15. ocean energy | OpenEI Community

    Open Energy Info (EERE)

    ocean energy Home Kch's picture Submitted by Kch(24) Member 15 July, 2014 - 07:07 MHK Cost Breakdown Structure Draft CBS current energy GMREC LCOE levelized cost of energy marine...

  16. current energy | OpenEI Community

    Open Energy Info (EERE)

    current energy Home Kch's picture Submitted by Kch(24) Member 15 July, 2014 - 07:07 MHK Cost Breakdown Structure Draft CBS current energy GMREC LCOE levelized cost of energy marine...

  17. LCOE | OpenEI Community

    Open Energy Info (EERE)

    LCOE Home Kch's picture Submitted by Kch(24) Member 15 July, 2014 - 07:07 MHK Cost Breakdown Structure Draft CBS current energy GMREC LCOE levelized cost of energy marine energy...

  18. marine energy | OpenEI Community

    Open Energy Info (EERE)

    marine energy Home Kch's picture Submitted by Kch(24) Member 15 July, 2014 - 07:07 MHK Cost Breakdown Structure Draft CBS current energy GMREC LCOE levelized cost of energy marine...

  19. GMREC | OpenEI Community

    Open Energy Info (EERE)

    GMREC Home Kch's picture Submitted by Kch(24) Member 15 July, 2014 - 07:07 MHK Cost Breakdown Structure Draft CBS current energy GMREC LCOE levelized cost of energy marine energy...

  20. levelized cost of energy | OpenEI Community

    Open Energy Info (EERE)

    levelized cost of energy Home Kch's picture Submitted by Kch(24) Member 15 July, 2014 - 07:07 MHK Cost Breakdown Structure Draft CBS current energy GMREC LCOE levelized cost of...

  1. A Theory for the Comparative RF Surface Fields at Destructive Breakdown for Various Metels

    SciTech Connect (OSTI)

    Wilson, Perry; /SLAC

    2006-03-20

    By destructive breakdown we mean a breakdown event that results in surface melting over large areas on the iris tip region of an accelerator structure. The melting is the result of the formation of macroscopic areas of plasma in contact with the surface. The plasma bombards the surface with an intense ion current ({approx}10{sup 8} A/cm{sup 2}), which is equivalent to a pressure on the order of a thousand Atmospheres. A radial gradient in the pressure produces a ponderomotive force that causes molten copper to migrate away from the iris tip, resulting in a measurable change in the iris shape. This distortion in the iris shape in turn produces an error in the cell-to-cell phase shift of the accelerating wave with a consequent loss in synchronism with the electron beam and a reduction in the effective accelerating gradient. Assuming a long lifetime is desired for the structure, such breakdowns must be avoided or at least limited in number. The accelerating gradient at which these breakdowns begin to occur imposes, therefore, an absolute limit on an operationally attainable gradient. The destructive breakdown limit (DBL) on the accelerating gradient depends on a number of factors, such as the geometry of the irises and coupler, the accuracy of the cell-to-cell tuning (''field flatness''), and the properties of the metal used in the high E-field regions of the structure. In this note we consider only the question of the dependence of the DBL on the metal used in the high surface field areas of the structure. There are also various types of non-destructive breakdowns (NDB's) that occur during the ''processing'' period that, after the initial application of high power, is necessary to bring the gradient up to the desired operating level. During this period, as the input power and gradient are gradually increased, thousands of such NDB's occur. These breakdowns produce a collapse in the fields in the structure as energy stored in the fields is absorbed at the breakdown

  2. Quantum Oscillations from Nodal Bilayer Magnetic Breakdown in...

    Office of Scientific and Technical Information (OSTI)

    Title: Quantum Oscillations from Nodal Bilayer Magnetic Breakdown in the Underdoped High Temperature Superconductor YBa2Cu3O6+x Authors: Sebastian, Suchitra E. ; Harrison, N. ; ...

  3. Laser-induced breakdown spectroscopy at high temperatures in...

    Office of Scientific and Technical Information (OSTI)

    electric power generation boiler burning biomass, coat, or both, (2) at the exit of a ... Language: English Subject: 03 NATURAL GAS; 09 BIOMASS FUELS; BIOMASS; BOILERS; BREAKDOWN; ...

  4. Pre-breakdown evaluation of gas discharge mechanisms in microgaps

    SciTech Connect (OSTI)

    Semnani, Abbas; Peroulis, Dimitrios; Venkattraman, Ayyaswamy; Alexeenko, Alina A.

    2013-04-29

    The individual contributions of various gas discharge mechanisms to total pre-breakdown current in microgaps are quantified numerically. The variation of contributions of field emission and secondary electron emission with increasing electric field shows contrasting behavior even for a given gap size. The total current near breakdown decreases rapidly with gap size indicating that microscale discharges operate in a high-current, low-voltage regime. This study provides the first such analysis of breakdown mechanisms and aids in the formulation of physics-based theories for microscale breakdown.

  5. From Organized High-Throughput Data to Phenomenological Theory using Machine Learning: The Example of Dielectric Breakdown

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kim, Chiho; Pilania, Ghanshyam; Ramprasad, Ramamurthy

    2016-02-02

    Understanding the behavior (and failure) of dielectric insulators experiencing extreme electric fields is critical to the operation of present and emerging electrical and electronic devices. Despite its importance, the development of a predictive theory of dielectric breakdown has remained a challenge, owing to the complex multiscale nature of this process. We focus on the intrinsic dielectric breakdown field of insulators—the theoretical limit of breakdown determined purely by the chemistry of the material, i.e., the elements the material is composed of, the atomic-level structure, and the bonding. Starting from a benchmark dataset (generated from laborious first principles computations) of the intrinsicmore » dielectric breakdown field of a variety of model insulators, simple predictive phenomenological models of dielectric breakdown are distilled using advanced statistical or machine learning schemes, revealing key correlations and analytical relationships between the breakdown field and easily accessible material properties. Lastly, the models are shown to be general, and can hence guide the screening and systematic identification of high electric field tolerant materials.« less

  6. Femtosecond laser induced breakdown for combustion diagnostics

    SciTech Connect (OSTI)

    Kotzagianni, M.; Couris, S.

    2012-06-25

    The focused beam of a 100 fs, 800 nm laser is used to induce a spark in some laminar premixed air-methane flames operating with variable fuel content (equivalence ratio). The analysis of the light escaping from the plasma revealed that the Balmer hydrogen lines, H{sub {alpha}} and H{sub {beta}}, and some molecular origin emissions were the most prominent spectral features, while the CN ({Beta}{sup 2}{Sigma}{sup +}-{Chi}{sup 2}{Sigma}{sup +}) band intensity was found to depend linearly with methane content, suggesting that femtosecond laser induced breakdown spectroscopy can be a useful tool for the in-situ determination and local mapping of fuel content in hydrocarbon-air combustible mixtures.

  7. About Cost Breakdown Structure for Wave Energy Device Created...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... Sensitvity Graphs Mean Wave Height (m) Wave Power Density (kWm) LCoE - centskWh 1.5 10.390967780483027 160.88775532305041 1.7 14.407267528007228 126.74104631588072 1.9 ...

  8. About Cost Breakdown Structure for River Current Device Created...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... 8.864346784966715 kWm2 Velocity Power Law Fit, "1 x" 6 Rotor Area 62.436 m2 Generator Rated Capacity 89.51 kW Energy Extraction Gearbox Efficiency 0.94 Average Extracted ...

  9. About Cost Breakdown Structure for Ocean Current Device Created...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... 1.7214753197850284E-2 1.5.5 Step-up Transformer 24.943310657596371 875000 ... System Requirements ABS DP Class 2 Station Keeping in 4-6 knot current Transit Speed of 8 ...

  10. Hanford tanks initiative (HTI) work breakdown structure (WBS)dictionary

    SciTech Connect (OSTI)

    Mckinney, K.E.

    1997-03-31

    This dictionary lists the scope, deliverables, and interfaces for the various work elements of the Hanford Tanks Initiative. Cost detail is included for information only.

  11. Preliminary Development of a Work Breakdown Structure (WBS) for...

    Office of Scientific and Technical Information (OSTI)

    Authors: Harrison, Thomas J. 1 ; Moses, Rebecca J. 1 ; Flanagan, George F. 1 + Show Author Affiliations Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States) ...

  12. DOE Work Breakdown Structure Handbook | Department of Energy

    Energy Savers [EERE]

    Vendor Communication Plan DOE Vendor Communication Plan As described in Policy Flash 2011-44, the Office of Federal Procurement Policy (OFPP) memorandum entitled "Myth-Busting: Addressing Misconceptions to Improve Communication with Industry during the Acquisition Process" required agencies to develop and submit a high-level vendor communication plan for OFPP approval. DOE's approved plan is attached. PF2012-12 DOE Vendor Communication Plan (43.97 KB) PF2012-12a.pdf (167.68 KB)

  13. X ray photoelectron analysis of oxide-semiconductor interface after breakdown in Al{sub 2}O{sub 3}/InGaAs stacks

    SciTech Connect (OSTI)

    Shekhter, P.; Palumbo, F.; Cohen Weinfeld, K.; Eizenberg, M.

    2014-09-08

    In this work, the post-breakdown characteristics of metal gate/Al{sub 2}O{sub 3}/InGaAs structures were studied using surface analysis by x ray photoelectron spectroscopy. The results show that for dielectric breakdown under positive bias, localized filaments consisting of oxidized substrate atoms (In, Ga and As) were formed, while following breakdown under negative bias, a decrease of oxidized substrate atoms was observed. Such differences in the microstructure at the oxide-semiconductor interface after breakdown for positive and negative voltages are explained by atomic diffusion of the contact atoms into the gate dielectric in the region of the breakdown spot by the current induced electro-migration effect. These findings show a major difference between Al{sub 2}O{sub 3}/InGaAs and SiO{sub 2}/Si interfaces, opening the way to a better understanding of the breakdown characteristics of III-V complementary-metal-oxide-semiconductor technology.

  14. Theory of the electronic and structural properties of solid state oxides

    SciTech Connect (OSTI)

    Chelikowsky, J.R.

    1990-01-01

    Studies on electronic and structural properties of solid state oxides continued. This quarter, studies have concentrated on silica. Progress is discussed in the following sections: interatomic potentials and the structural properties of silica; chemical reactivity and covalent/metallic bonding on Si clusters; and surface and thermodynamic interatomic forces fields for silicon. 64 refs., 20 figs., 5 tabs. (CBS)

  15. High-voltage atmospheric breakdown across intervening rutile dielectrics.

    SciTech Connect (OSTI)

    Williamson, Kenneth Martin; Simpson, Sean; Coats, Rebecca Sue; Jorgenson, Roy Eberhardt; Hjalmarson, Harold Paul; Pasik, Michael Francis

    2013-09-01

    This report documents work conducted in FY13 on electrical discharge experiments performed to develop predictive computational models of the fundamental processes of surface breakdown in the vicinity of high-permittivity material interfaces. Further, experiments were conducted to determine if free carrier electrons could be excited into the conduction band thus lowering the effective breakdown voltage when UV photons (4.66 eV) from a high energy pulsed laser were incident on the rutile sample. This report documents the numerical approach, the experimental setup, and summarizes the data and simulations. Lastly, it describes the path forward and challenges that must be overcome in order to improve future experiments for characterizing the breakdown behavior for rutile.

  16. Breakdown voltage improvement of standard MOS technologies targeted at smart power

    SciTech Connect (OSTI)

    Santos, P.M.; Simas, M.I.C.; Lanca, M.; Finco, S.; Behrens, F.H.

    1995-12-31

    This paper presents and discusses trade-offs of three different design techniques intended to improve the breakdown voltage of n-type lateral medium power transistors to be fabricated in a conventional low cost CMOS technology. A thorough analysis of the static and dynamic characteristics of the modified structures was carried out with the support of a two-dimensional device simulator. The motivation behind this work was the construction of a low cost smart power microsystem, including control, sensing and protection circuitries, targeted at an electronic ballast for efficient control of the power delivered to fluorescent lamps.

  17. A relationship between statistical time to breakdown distributions and pre-breakdown negative differential resistance at nanometric scale

    SciTech Connect (OSTI)

    Foissac, R.; Blonkowski, S.; Delcroix, P.; Kogelschatz, M.

    2014-07-14

    Using an ultra-high vacuum Conductive atomic force microscopy (C-AFM) current voltage, pre-breakdown negative differential resistance (NDR) characteristics are measured together with the time dependent dielectric breakdown (TDDB) distributions of Si/SiON (1.4 and 2.6?nm thick). Those experimental characteristics are systematically compared. The NDR effect is modelled by a conductive filament growth. It is showed that the Weibull TDDB statistic distribution scale factor is proportional to the growth rate of an individual filament and then has the same dependence on the electric field. The proportionality factor is a power law of the ratio between the surfaces of the CAFM tip and the filament's top. Moreover, it was found that, for the high fields used in those experiments, the TDDB acceleration factor as the growth rate characteristic is proportional to the Zener tunnelling probability. Those observations are discussed in the framework of possible breakdown or forming mechanism.

  18. Overview of applications of Laser-Induced Breakdown Spectroscopy (LIBS)

    SciTech Connect (OSTI)

    Cremers, D.A.

    1987-01-01

    Laser-induced breakdown spectroscopy (LIBS) is a method of performing elemental analyses of solids, liquids, and gases using the microplasma produced by a focused laser pulse. Because the microplasma is formed by optical radiation, LIBS has some important advantages compared to conventional laboratory based analytical methods. Three applications are discussed which use the LIBS method. 6 refs., 8 figs., 2 tabs.

  19. (Tenth international conference on conduction and breakdown in dielectric liquids)

    SciTech Connect (OSTI)

    Christophorou, L.G.

    1990-10-05

    The traveler attended the 10th International Conference on Conduction and Breakdown in dielectric Liquids held in Grenoble, France, September 10--14, 1990. He chaired the opening session of the conference, presented one paper, co-authored a second paper presented at the meeting, participated in the discussions during the formal sessions, and had informal discussions with many of the participants.

  20. Improved Laser Induced Breakdown Spectroscopy (LIBS) Elemental Composition

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Detection System - Energy Innovation Portal Industrial Technologies Industrial Technologies Geothermal Geothermal Find More Like This Return to Search Improved Laser Induced Breakdown Spectroscopy (LIBS) Elemental Composition Detection System A device to measure subsurface gases, liquids, and solids at subsurface conditions National Energy Technology Laboratory Contact NETL About This Technology Technology Marketing Summary This device can measure subsurface gases, liquids, and solids at

  1. Al00.3Ga0.7N PN diode with breakdown voltage >1600 V

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Allerman, A. A.; Armstrong, A. M.; Fischer, A. J.; Dickerson, J. R.; Crawford, M. H.; King, M. P.; Moseley, M. W.; Wierer, J. J.; Kaplar, R. J.

    2016-07-21

    Demonstration of Al00.3Ga0.7N PN diodes grown with breakdown voltages in excess of 1600 V is reported. The total epilayer thickness is 9.1 μm and was grown by metal-organic vapour-phase epitaxy on 1.3-mm-thick sapphire in order to achieve crack-free structures. A junction termination edge structure was employed to control the lateral electric fields. A current density of 3.5 kA/cm2 was achieved under DC forward bias and a reverse leakage current <3 nA was measured for voltages <1200 V. The differential on-resistance of 16 mΩ cm2 is limited by the lateral conductivity of the n-type contact layer required by the front-surface contactmore » geometry of the device. An effective critical electric field of 5.9 MV/cm was determined from the epilayer properties and the reverse current–voltage characteristics. To our knowledge, this is the first aluminium gallium nitride (AlGaN)-based PN diode exhibiting a breakdown voltage in excess of 1 kV. Finally, we note that a Baliga figure of merit (Vbr2/Rspec,on) of 150 MW/cm2 found is the highest reported for an AlGaN PN diode and illustrates the potential of larger-bandgap AlGaN alloys for high-voltage devices.« less

  2. Analysis of organic vapors with laser induced breakdown spectroscopy

    SciTech Connect (OSTI)

    Nozari, Hadi; Tavassoli, Seyed Hassan; Rezaei, Fatemeh

    2015-09-15

    In this paper, laser induced breakdown spectroscopy (LIBS) is utilized in the study of acetone, ethanol, methanol, cyclohexane, and nonane vapors. Carbon, hydrogen, oxygen, and nitrogen atomic emission spectra have been recorded following laser-induced breakdown of the organic vapors that are mixed with air inside a quartz chamber at atmospheric pressure. The plasma is generated with focused, Q-switched Nd:YAG radiation at the wavelength of 1064 nm. The effects of ignition and vapor pressure are discussed in view of the appearance of the emission spectra. The recorded spectra are proportional to the vapor pressure in air. The hydrogen and oxygen contributions diminish gradually with consecutive laser-plasma events without gas flow. The results show that LIBS can be used to characterize organic vapor.

  3. Laser-induced breakdown spectroscopy for specimen analysis

    DOE Patents [OSTI]

    Kumar, Akshaya; Yu-Yueh, Fang; Burgess, Shane C.; Singh, Jagdish P.

    2006-08-15

    The present invention is directed to an apparatus, a system and a method for detecting the presence or absence of trace elements in a biological sample using Laser-Induced Breakdown Spectroscopy. The trace elements are used to develop a signature profile which is analyzed directly or compared with the known profile of a standard. In one aspect of the invention, the apparatus, system and method are used to detect malignant cancer cells in vivo.

  4. Laser-induced breakdown spectroscopy of alcohols and protein solutions

    SciTech Connect (OSTI)

    Melikechi, N.; Ding, H.; Marcano, O. A.; Rock, S.

    2008-04-15

    We report on the use of laser-induced breakdown spectroscopy for the study of organic samples that exhibit similar elemental composition. We evaluate the method for its potential application for the measurement of small spectroscopic differences between samples such as alcohols and water solution of proteins. We measure differences in the relative amplitudes of the oxygen peaks for alcohols and find that these correlate with the relative amount of oxygen atoms within the molecule. We also show that the spectra of proteins reveal differences that can be used for their detection and identification.

  5. Gas breakdown driven by L band short-pulse high-power microwave

    SciTech Connect (OSTI)

    Yang Yiming; Yuan Chengwei; Qian Baoliang

    2012-12-15

    High power microwave (HPM) driven gas breakdown is a major factor in limiting the radiation and transmission of HPM. A method that HPM driven gas breakdown could be obtained by changing the aperture of horn antenna is studied in this paper. Changing the effective aperture of horn antenna can adjust the electric field in near field zone, leading to gas breakdown. With this method, measurements of air and SF{sub 6} breakdowns are carried out on a magnetically insulated transmission-line oscillators, which is capable of generating HPM with pulse duration of 30 ns, and frequency of 1.74 GHz. The typical breakdown waveforms of air and SF{sub 6} are presented. Besides, the breakdown field strengths of the two gases are derived at different pressures. It is found that the effects of air and SF{sub 6} breakdown on the transmission of HPM are different: air breakdown mainly shortens the pulse width of HPM while SF{sub 6} breakdown mainly reduces the peak output power of HPM. The electric field threshold of SF{sub 6} is about 2.4 times larger than that of air. These differences suggest that gas properties have a great effect on the transmission characteristic of HPM in gases.

  6. Studies on gas breakdown in pulsed radio frequency atmospheric pressure glow discharges

    SciTech Connect (OSTI)

    Huo, W. G. [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116023 (China) [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116023 (China); School of Physics and Electronic Technology, Liaoning Normal University, Dalian 116029 (China); Jian, S. J.; Yao, J.; Ding, Z. F., E-mail: zfding@dlut.edu.cn [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116023 (China)

    2014-05-15

    In pulsed RF atmospheric pressure glow discharges, the gas breakdown judged by the rapid drop in the amplitude of the pulsed RF voltage is no longer universally true. The steep increment of the plasma-absorbed RF power is proposed to determine the gas breakdown. The averaged plasma-absorbed RF power over a pulse period is used to evaluate effects of the preceding pulsed RF discharge on the breakdown voltage of the following one, finding that the breakdown voltage decreases with the increment in the averaged plasma-absorbed RF power under constant pulse duty ratio. Effects of the pulse off-time on the breakdown voltage and the breakdown delay time are also studied. The obtained dependence of the breakdown voltage on the pulse off-time is indicative of the transitional plasma diffusion processes in the afterglow. The breakdown voltage varies rapidly as the plasma diffuses fast in the region of moderate pulse off-time. The contribution of nitrogen atom recombination at the alumina surface is demonstrated in the prolonged memory effect on the breakdown delay time vs. the pulse off-time and experimentally validated by introducing a trace amount of nitrogen into argon at short and long pulse off-times.

  7. Visual and Electrical Evidence Supporting a Two-Plasma Mechanism of Vacuum Breakdown Initiation

    SciTech Connect (OSTI)

    Castano-Giraldo, C.; Aghazarian, Maro; Caughman, John B; Ruzic, D. N.

    2012-01-01

    The energy available during vacuum breakdown between copper electrodes at high vacuum was limited using resistors in series with the vacuum gap and arresting diodes. Surviving features observed with SEM in postmortem samples were tentatively correlated with electrical signals captured during breakdown using a Rogowski coil and a high-voltage probe. The visual and electrical evidence is consistent with the qualitative model of vacuum breakdown by unipolar arc formation by Schwirzke [1, 2]. The evidence paints a picture of two plasmas of different composition and scale being created during vacuum breakdown: an initial plasma made of degassed material from the metal surface, ignites a plasma made up of the electrode material.

  8. Breakdown in hydrogen and deuterium gases in static and radio-frequency fields

    SciTech Connect (OSTI)

    Korolov, I. Donkó, Z.

    2015-09-15

    We report the results of a combined experimental and modeling study of the electrical breakdown of hydrogen and deuterium in static (DC) and radio-frequency (RF) (13.56 MHz) electric fields. For the simulations of the breakdown events, simplified models are used and only electrons are traced by Monte Carlo simulation. The experimental DC Paschen curve of hydrogen is used for the determination of the effective secondary electron emission coefficient. A very good agreement between the experimental and the calculated RF breakdown characteristics for hydrogen is found. For deuterium, on the other hand, presently available cross section sets do not allow a reproduction of RF breakdown characteristics.

  9. Scaling law for direct current field emission-driven microscale gas breakdown

    SciTech Connect (OSTI)

    Venkattraman, A.; Alexeenko, A. A.

    2012-12-15

    The effects of field emission on direct current breakdown in microscale gaps filled with an ambient neutral gas are studied numerically and analytically. Fundamental numerical experiments using the particle-in-cell/Monte Carlo collisions method are used to systematically quantify microscale ionization and space-charge enhancement of field emission. The numerical experiments are then used to validate a scaling law for the modified Paschen curve that bridges field emission-driven breakdown with the macroscale Paschen law. Analytical expressions are derived for the increase in cathode electric field, total steady state current density, and the ion-enhancement coefficient including a new breakdown criterion. It also includes the effect of all key parameters such as pressure, operating gas, and field-enhancement factor providing a better predictive capability than existing microscale breakdown models. The field-enhancement factor is shown to be the most sensitive parameter with its increase leading to a significant drop in the threshold breakdown electric field and also to a gradual merging with the Paschen law. The proposed scaling law is also shown to agree well with two independent sets of experimental data for microscale breakdown in air. The ability to accurately describe not just the breakdown voltage but the entire pre-breakdown process for given operating conditions makes the proposed model a suitable candidate for the design and analysis of electrostatic microscale devices.

  10. Breakdown of semiclassical methods in de Sitter space

    SciTech Connect (OSTI)

    Burgess, C.P.; Holman, R.; Leblond, L.; Shandera, S. E-mail: rh4a@andrew.cmu.edu E-mail: sshandera@perimeterinstitute.ca

    2010-10-01

    Massless interacting scalar fields in de Sitter space have long been known to experience large fluctuations over length scales larger than Hubble distances. A similar situation arises in condensed matter physics in the vicinity of a critical point, and in this better-understood situation these large fluctuations indicate the failure in this regime of mean-field methods. We argue that for non-Goldstone scalars in de Sitter space, these fluctuations can also be interpreted as signaling the complete breakdown of the semi-classical methods widely used throughout cosmology. By power-counting the infrared properties of Feynman graphs in de Sitter space we find that for a massive scalar interacting through a λ φ{sup 4} interaction, control over the loop approximation is lost for masses smaller than m ≅ √λ H/2π, where H is the Hubble scale. We briefly discuss some potential implications for inflationary cosmology.

  11. Apparatus, system, and method for laser-induced breakdown spectroscopy

    SciTech Connect (OSTI)

    Effenberger, Jr., Andrew J; Scott, Jill R; McJunkin, Timothy R

    2014-11-18

    In laser-induced breakdown spectroscopy (LIBS), an apparatus includes a pulsed laser configured to generate a pulsed laser signal toward a sample, a constructive interference object and an optical element, each located in a path of light from the sample. The constructive interference object is configured to generate constructive interference patterns of the light. The optical element is configured to disperse the light. A LIBS system includes a first and a second optical element, and a data acquisition module. The data acquisition module is configured to determine an isotope measurement based, at least in part, on light received by an image sensor from the first and second optical elements. A method for performing LIBS includes generating a pulsed laser on a sample to generate light from a plasma, generating constructive interference patterns of the light, and dispersing the light into a plurality of wavelengths.

  12. Dynamics of optical breakdown in air induced by single and double nanosecond laser pulses

    SciTech Connect (OSTI)

    Mahdieh, Mohammad Hossein Akbari Jafarabadi, Marzieh

    2015-12-15

    In this paper, an optical breakdown in air induced by single and double nanosecond laser pulses was studied. A high power Nd:YAG laser beam was used for producing optical breakdown plasma in the air. The dynamics of breakdown plasma were studied using an optical probe beam. A portion of the laser beam was used, as the probe beam and was aligned to propagate (perpendicular to the pump beam) through the breakdown region. The transmission of the probe beam (through the breakdown region) was temporally measured for both single and double pulse irradiations. The results were used to describe the evolution of the induced plasma in both conditions. These results show that the plasma formation time and its absorptivity are strongly dependent on the single or double pulse configurations.

  13. Review of recent theories and experiments for improving high-power microwave window breakdown thresholds

    SciTech Connect (OSTI)

    Chang Chao; Liu Guozhi; Tang Chuanxiang; Chen Changhua; Fang Jinyong

    2011-05-15

    Dielectric window breakdown is a serious challenge in high-power microwave (HPM) transmission and radiation. Breakdown at the vacuum/dielectric interface is triggered by multipactor and finally realized by plasma avalanche in the ambient desorbed or evaporated gas layer above the dielectric. Methods of improving breakdown thresholds are key challenges in HPM systems. First, the main theoretical and experimental progress is reviewed. Next, the mechanisms of multipactor suppression for periodic rectangular and triangular surface profiles by dynamic analysis and particle-in-cell simulations are surveyed. Improved HPM breakdown thresholds are demonstrated by proof-of-principle and multigigawatt experiments. The current theories and experiments of using dc magnetic field to resonantly accelerate electrons to suppress multipactor are also synthesized. These methods of periodic profiles and magnetic field may solve the key issues of HPM vacuum dielectric breakdown.

  14. Electric properties and carrier multiplication in breakdown sites in multi-crystalline silicon solar cells

    SciTech Connect (OSTI)

    Schneemann, Matthias; Carius, Reinhard; Rau, Uwe; Kirchartz, Thomas

    2015-05-28

    This paper studies the effective electrical size and carrier multiplication of breakdown sites in multi-crystalline silicon solar cells. The local series resistance limits the current of each breakdown site and is thereby linearizing the current-voltage characteristic. This fact allows the estimation of the effective electrical diameters to be as low as 100 nm. Using a laser beam induced current (LBIC) measurement with a high spatial resolution, we find carrier multiplication factors on the order of 30 (Zener-type breakdown) and 100 (avalanche breakdown) as new lower limits. Hence, we prove that also the so-called Zener-type breakdown is followed by avalanche multiplication. We explain that previous measurements of the carrier multiplication using thermography yield results higher than unity, only if the spatial defect density is high enough, and the illumination intensity is lower than what was used for the LBIC method. The individual series resistances of the breakdown sites limit the current through these breakdown sites. Therefore, the measured multiplication factors depend on the applied voltage as well as on the injected photocurrent. Both dependencies are successfully simulated using a series-resistance-limited diode model.

  15. A study of dielectric breakdown along insulators surrounding conductors in liquid argon

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Lockwitz, Sarah; Jostlein, Hans

    2016-03-22

    High voltage breakdown in liquid argon is an important concern in the design of liquid argon time projection chambers, which are often used as neutrino and dark matter detectors. We have made systematic measurements of breakdown voltages in liquid argon along insulators surrounding negative rod electrodes where the breakdown is initiated at the anode. The measurements were performed in an open cryostat filled with commercial grade liquid argon exposed to air, and not the ultra-pure argon required for electron drift. While not addressing all high voltage concerns in liquid argon, these measurements have direct relevance to the design of highmore » voltage feedthroughs especially for averting the common problem of flash-over breakdown. The purpose of these tests is to understand the effects of materials, of breakdown path length, and of surface topology for this geometry and setup. We have found that the only material-specific effects are those due to their permittivity. We have found that the breakdown voltage has no dependence on the length of the exposed insulator. Lastly, a model for the breakdown mechanism is presented that can help inform future designs.« less

  16. Analytical investigation of electrical breakdown properties in a nitrogen-SF{sub 6} mixture gas

    SciTech Connect (OSTI)

    Uhm, Han S.; Byeon, Yong S.; Song, Ki B.; Choi, Eun H.; Ryu, Han-Yong; Lee, Jaimin

    2010-11-15

    The electrical breakdown properties in nitrogen gas mixed with SF{sub 6} are analytically investigated in this article by making use of the ionization and attachment coefficients of the mixed gas. The ionization coefficients of nitrogen and SF{sub 6} gas are obtained in terms of the electron temperature T{sub e} by assuming a Maxwellian distribution of the electron energy. The attachment coefficient of SF{sub 6} gas is also obtained in terms of the gas temperature T{sub e}. An algebraic equation is obtained, relating explicitly the electron breakdown temperature T{sub b} in terms of the SF{sub 6} mole fraction {chi}. It was found from this equation that the breakdown temperature T{sub b} increases from approximately 2 to 5.3 eV as the mole fraction {chi} increases from zero to unity. The breakdown temperature T{sub b} of the electrons increases very rapidly from a small value and then approaches 5.3 eV slowly as the SF{sub 6} mole fraction increases from zero to unity. This indicates that even a small mole fraction of SF{sub 6} in the gas dominates the electron behavior in the breakdown system. The breakdown electric field E{sub b} derived is almost linearly proportional to the breakdown electron temperature T{sub b}. The experimental data agree remarkably well with the theoretical results. Therefore, it is concluded that even a small fraction of SF{sub 6} gas dominates nitrogen in determining the breakdown field. In this context, nearly 25% of the SF{sub 6} mole fraction provides a reasonable enhancement of the breakdown field for practical applications.

  17. Experimental investigation of breakdown voltage characteristics of single-gap and multigap pseudosparks

    SciTech Connect (OSTI)

    Liu, C.J.; Rhee, M.J.

    1995-06-01

    Simple empirical scaling laws that can be applied universally are determined for breakdown voltage characteristics of single-gap and multigap pseudosparks. For the single-gap pseudospark, the breakdown voltage is found to be a function of the product of the gas pressure squared, the anode-cathode gap distance, and the hollow cavity diameter, p{sup 2}dD, and a function of the product pd for a gap distance less than and greater than three times the cavity diameter, respectively. For the multigap pseudospark, however, the breakdown voltage is found to be only a function of the product p{sup 2}dD.

  18. Laser-induced breakdown spectroscopy in industrial and security applications

    SciTech Connect (OSTI)

    Bol'shakov, Alexander A.; Yoo, Jong H.; Liu Chunyi; Plumer, John R.; Russo, Richard E.

    2010-05-01

    Laser-induced breakdown spectroscopy (LIBS) offers rapid, localized chemical analysis of solid or liquid materials with high spatial resolution in lateral and depth profiling, without the need for sample preparation. Principal component analysis and partial least squares algorithms were applied to identify a variety of complex organic and inorganic samples. This work illustrates how LIBS analyzers can answer a multitude of real-world needs for rapid analysis, such as determination of lead in paint and children's toys, analysis of electronic and solder materials, quality control of fiberglass panels, discrimination of coffee beans from different vendors, and identification of generic versus brand-name drugs. Lateral and depth profiling was performed on children's toys and paint layers. Traditional one-element calibration or multivariate chemometric procedures were applied for elemental quantification, from single laser shot determination of metal traces at {approx}10 {mu}g/g to determination of halogens at 90 {mu}g/g using 50-shot spectral accumulation. The effectiveness of LIBS for security applications was demonstrated in the field by testing the 50-m standoff LIBS rasterizing detector.

  19. Where do the default values for the cost of system breakdowns...

    Open Energy Info (EERE)

    Where do the default values for the cost of system breakdowns come from in SAM, for direct and indirect costs, such as 0.63 per DC watt for panels. 0.18 for inverters. Are these...

  20. Effects of load voltage on voltage breakdown modes of electrical exploding aluminum wires in air

    SciTech Connect (OSTI)

    Wu, Jian; Li, Xingwen Yang, Zefeng; Wang, Kun; Chao, Youchuang; Shi, Zongqian; Jia, Shenli; Qiu, Aici

    2015-06-15

    The effects of the load voltage on the breakdown modes are investigated in exploding aluminum wires driven by a 1 kA, 0.1 kA/ns pulsed current in air. From laser probing images taken by laser shadowgraphy, schlieren imaging, and interferometry, the position of the shockwave front, the plasma channel, and the wire core edge of the exploding product can be determined. The breakdown mode makes a transition from the internal mode, which involves breakdown inside the wire core, to the shunting mode, which involves breakdown in the compressed air, with decreasing charging voltage. The breakdown electrical field for a gaseous aluminum wire core of nearly solid density is estimated to be more than 20 kV/cm, while the value for gaseous aluminum of approximately 0.2% solid density decreases to 15–20 kV/cm. The breakdown field in shunting mode is less than 20 kV/cm and is strongly affected by the vaporized aluminum, the desorbed gas, and the electrons emitted from the wire core during the current pause. Ohmic heating during voltage collapses will induce further energy deposition in the current channel and thus will result in different expansion speeds for both the wire core and the shockwave front in the different modes.

  1. High stored-energy breakdown tests on electrodes made of stainless steel, copper, titanium and molybdenum

    SciTech Connect (OSTI)

    Esch, H. P. L. de Simonin, A.; Grand, C.

    2015-04-08

    IRFM have conducted resilience tests on electrodes made of Cu, stainless steel 304L, Ti and Mo against breakdowns up to 170 kV and 300 J. The tests of the 10×10 cm{sup 2} electrodes have been performed at an electrode distance d=11 mm under vacuum (P∼5×10{sup −6} mbar). No great difference in voltage holding between the materials could be identified; all materials could reach a voltage holding between 140 and 170 kV over the 11 mm gap, i.e. results scatter within a ±10% band. After exposure to ∼10000 seconds of high-voltage (HV) on-time, having accumulated ∼1000 breakdowns, the electrodes were inspected. The anodes were covered with large and small craters. The rugosity of the anodes had increased substantially, that of the cathodes to a lesser extent. The molybdenum electrodes are least affected, but this does not show in their voltage holding capability. It is hypothesized that penetrating high-energy electrons from the breakdown project heat below the surface of the anode and cause a micro-explosion of material when melting point is exceeded. Polished electrodes have also been tested. The polishing results in a substantially reduced breakdown rate in the beginning, but after having suffered a relatively small number (∼100) of breakdowns, the polished electrodes behaved the same as the unpolished ones.

  2. Electrical Breakdown Physics in Photoconductive Semiconductor Switches (PCSS).

    SciTech Connect (OSTI)

    Mar, Alan; Zutavern, Fred J.; Vawter, Gregory A.; Hjalmarson, Harold P.; Gallegos, Richard Joseph; Bigman, Verle Howard

    2016-01-01

    of 200kV (DC) and 5kA current that can be stacked in parallel to achieve 100's of kA with 10e5 shot lifetime. The new vertical switch design configuration generates parallel filaments in the bulk GaAs (as opposed to just beneath the surface as in previous designs) to achieve breakdown fields close to the maximum for the bulk GaAs while operating in air, and with 2-D scalability of the number of current-sharing filaments. This design also may be highly compatible with 2-D VCSEL arrays for optical triggering. The demonstration of this design in this LDRD utilized standard thickness wafers to trigger 0.4kA at 35kV/cm (limited by 0.6mm wafer thickness), tested to 1e5 shots with no detectable degradation of switch performance. Higher fields, total current, and switching voltages would be achievable with thicker GaAs wafers. Another important application pursued in this LDRD is the use of PCSS for trigger generator applications. Conventional in-plane PCSS have achieved triggering of a 100kV sparkgap (Kinetech-type) switch of the type similar to switches being considered for accelerator upgrades. The trigger is also being developed for pulsed power for HPM applications that require miniaturization and robust performance in noisy compact environments. This has spawned new programs for developing this technology, including an STTR for VCSEL trigger laser integration, also pursuing other follow-on applications.

  3. Note: A novel technique for analysis of aqueous solutions by laser-induced breakdown spectroscopy

    SciTech Connect (OSTI)

    Rusak, D. A.; Bell, Z. T.; Anthony, T. P.

    2015-11-15

    Surface-enhanced Raman spectroscopy (SERS) substrates typically consist of gold or silver nanoparticles deposited on a non-conductive substrate. In Raman spectroscopy, the nanoparticles produce an enhancement of the electromagnetic field which, in turn, leads to greater electronic excitation of molecules in the local environment. Here, we show that these same surfaces can be used to enhance the signal-to-noise ratio obtained in laser-induced breakdown spectroscopy of aqueous solutions. In this case, the SERS substrates not only lower breakdown thresholds and lead to more efficient plasma initiation but also provide an appropriately wettable surface for the deposition of the liquid. We refer to this technique as surface-enhanced laser-induced breakdown spectroscopy.

  4. The quantum mechanics of ion-enhanced field emission and how it influences microscale gas breakdown

    SciTech Connect (OSTI)

    Li, Yingjie; Go, David B.

    2014-09-14

    The presence of a positive gas ion can enhance cold electron field emission by deforming the potential barrier and increasing the tunneling probability of electronsa process known as ion-enhanced field emission. In microscale gas discharges, ion-enhanced field emission produces additional emission from the cathode and effectively reduces the voltage required to breakdown a gaseous medium at the microscale (<10 ?m). In this work, we enhance classic field emission theory by determining the impact of a gaseous ion on electron tunneling and compute the effect of ion-enhanced field emission on the breakdown voltage. We reveal that the current density for ion-enhanced field emission retains the same scaling as vacuum cold field emission and that this leads to deviations from traditional breakdown theory at microscale dimensions.

  5. Single and repetitive short-pulse high-power microwave window breakdown

    SciTech Connect (OSTI)

    Chang, C.; Tang, C. X.; Shao, H.; Chen, C. H.; Huang, W. H.

    2010-05-15

    The mechanisms of high-power microwave breakdown for single and repetitive short pulses are analyzed. By calculation, multipactor saturation with electron density much higher than the critical plasma density is found not to result in microwave cutoff. It is local high pressure about Torr class that rapid plasma avalanche and final breakdown are realized in a 10-20 ns short pulse. It is found by calculation that the power deposited by saturated multipactor and the rf loss of protrusions are sufficient to induce vaporizing surface material and enhancing the ambient pressure in a single short pulse. For repetitive pulses, the accumulation of heat and plasma may respectively carbonize the surface material and lower the repetitive breakdown threshold.

  6. Acoustic effects at interaction of laser radiation with a liquid accompanied by optical breakdown

    SciTech Connect (OSTI)

    Bulanov, A. V.; Nagorny, I. G.

    2012-09-04

    The experimental researches of acoustic emission from optical breakdown in liquids are presented. Spectral characteristics and power of the acoustic waves generated in a liquid by optical breakdown at interaction of laser radiation with the wavelength of 532 nanometers were studied. It is shown, that two spectral maxima characterizing acoustic emission are observed. The shift of low-frequency maximum depending on the laser energy pulse is observed. As a whole, the linear dependence of acoustic pressure on the energy of laser pulse is observed. It is shown, that using acoustic data it is possible to reproduce function R(t) which will be in accord with characteristic dependences R(t), obtained from optical data. The last is especially important for breakdown studying in opaque environments.

  7. Breakdown assisted by a novel electron drift injection in the J-TEXT tokamak

    SciTech Connect (OSTI)

    Wang, Nengchao; Jin, Hai; Zhuang, Ge Ding, Yonghua; Pan, Yuan; Cen, Yishun; Chen, Zhipeng; Huang, Hai; Liu, Dequan; Rao, Bo; Zhang, Ming; Zou, Bichen

    2014-07-15

    A novel electron drift injection (EDI) system aiming to improve breakdown behavior has been designed and constructed on the Joint Texas EXperiment Tokamak Tokamak. Electrons emitted by the system undergo the EB drift, ?B drift and curvature drift in sequence in order to traverse the confining magnetic field. A local electrostatic well, generated by a concave-shaped plate biased more negative than the cathode, is introduced to interrupt the emitted electrons moving along the magnetic field line (in the parallel direction) in an attempt to bring an enhancement of the injection efficiency and depth. A series of experiments have demonstrated the feasibility of this method, and a penetration distance deeper than 9.5 cm is achieved. Notable breakdown improvements, including the reduction of breakdown delay and average loop voltage, are observed for discharges assisted by EDI. The lower limit of successfully ionized pressure is expanded.

  8. Agenda CBS Public Meeting-Atlanta

    Energy Savers [EERE]

    dispute system and process design consultations and training for resolving environmental and land disputes in Estonia, IsraelWest Bank, Nicaragua, Kazakhstan, Russia, and Germany. ...

  9. Agenda CBS Public Meeting-Sacramento

    Broader source: Energy.gov (indexed) [DOE]

    Sacramento, California April 26, 2016 Dr. James David Ballard is a Professor of Sociology at California State University in Northridge (CSUN), California. Professor of Sociology ...

  10. Agenda CBS Public Meeting-Tempe

    Broader source: Energy.gov (indexed) [DOE]

    was born and raised in Grants New Mexico--the onetime uranium capital of the world. ... their "indirect land use change" and food price effects, and the importance of time and ...

  11. Agenda CBS Public Meeting-Boise

    Broader source: Energy.gov (indexed) [DOE]

    Boise, Idaho July 14, 2016 Beatrice Brailsford, Nuclear Program Director, Snake River Alliance the 1995 Settlement Agreement, which gave Idaho a strong shield against commercial ...

  12. Agenda CBS Public Meeting-Atlanta

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Elliott, Ph.D., Associate Director Georgia Institute of Technology's Center for Quality Growth and Regional Development CONSENT- BASED SITING CONSENT-BASED SITING PUBLIC MEETING ...

  13. Agenda CBS Public Meeting-Sacramento

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    David Ballard, Ph.D., Professor of Sociology CONSENT- BASED SITING CONSENT-BASED SITING PUBLIC MEETING Holiday Inn Capitol Plaza-Sacramento 300 J Street Sacramento, CA 95814 April ...

  14. Agenda CBS Public Meeting-Boise

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Talia T. Martin, Tribal/DOE Program Director, Shoshone-Bannock Tribes CONSENT- BASED SITING CONSENT-BASED SITING PUBLIC MEETING Boise Centre 850 West Front Street Boise, ID 83702 July 14, 2016 4:00-5:00 PM Informal Open House and Poster Session (Before Meeting Begins) 5:00-5:15 PM Welcoming Remarks David Leroy, Trial Lawyer, Former Nuclear Waste Negotiator 5:15-5:30 PM Moving Forward with Consent-Based Siting John Kotek, Acting Assistant Secretary for Nuclear Energy, Department of Energy

  15. Agenda CBS Public Meeting-Denver

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Maury Galbraith, Executive Director, Western Interstate Energy Board CONSENT- BASED SITING CONSENT-BASED SITING PUBLIC MEETING Embassy Suites Denver - Stapleton 4444 Havana Street Denver, CO 80239 May 24, 2016 4:00-5:00 PM Informal Open House and Poster Session (Before Meeting Begins) 5:00-5:15 PM Welcoming Remarks Mike Sullivan, Former Governor of Wyoming 5:15-5:30 PM Moving Forward with Consent-Based Siting John Kotek, Acting Assistant Secretary for Nuclear Energy, Department of Energy

  16. Agenda CBS Public Meeting-Minneapolis

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Rod McCullum, Senior Director, Used Fuel and Decommissioning, Nuclear Energy Institute CONSENT- BASED SITING CONSENT-BASED SITING PUBLIC MEETING Hilton Minneapolis 1001 Marquette Avenue Minneapolis, MN 55403 July 21, 2016 4:00-5:00 PM Informal Open House and Poster Session (Before Meeting Begins) 5:00-5:15 PM Welcoming Remarks John Tuma, Commissioner, Minnesota Public Utilities Commission 5:15-5:30 PM Moving Forward with Consent-Based Siting John Kotek, Acting Assistant Secretary for Nuclear

  17. Agenda CBS Public Meeting-Minneapolis

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Minneapolis, Minnesota July 21, 2016 Shelley Buck, President, Prairie Island Indian Community Tribal Council Buck has a bachelor's degree in business accounting from Indiana University and master's degree in Sports Management from Concordia University. She is currently serving as a board member of the Twins Community Fund and has also served as a board member of the Native Vote Alliance of Minnesota. President Shelley Buck is serving her third term on Prairie Island Tribal Council. Prior to

  18. Agenda CBS Public Meeting-Sacramento

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Sacramento, California April 26, 2016 Dr. James David Ballard is a Professor of Sociology at California State University in Northridge (CSUN), California. Professor of Sociology James David Ballard Dr. Ballard received his doctorate from the University of Nevada Las Vegas. His concentrations included political sociology, criminology and deviance. He received his Masters of Arts in General Studies: Economics and Political Science and a Bachelors in Science in Sociology from Jacksonville State

  19. Agenda CBS Public Meeting-Sacramento

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    David Ballard, Ph.D., Professor of Sociology CONSENT- BASED SITING CONSENT-BASED SITING PUBLIC MEETING Holiday Inn Capitol Plaza-Sacramento 300 J Street Sacramento, CA 95814 April 26, 2016 4:00-5:00 PM Informal Open House and Poster Session (Before Meeting Begins) 5:00-5:15 PM Welcoming Remarks Robert Weisenmiller, Chair to the California Energy Commission 5:15-5:30 PM Moving Forward with Consent-Based Siting John Kotek, Acting Assistant Secretary for Nuclear Energy, Department of Energy

  20. Agenda CBS Public Meeting-Boston

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    PM Welcoming Remarks Marge Kilkelly, Senior Policy Advisor to U.S. Senator Angus S. King Jr. 5:15-5:30 PM Moving Forward with Consent-Based Siting John Kotek, Acting Assistant ...

  1. Microsoft Word - Consolidated Verbatim Transcript CBS Meeting...

    Office of Environmental Management (EM)

    ... for siting future nuclear waste is really a key element. ... we have in California like 3,000 metric tons of spent fuel. ... there; again, we need panels like that with some sort ...

  2. Agenda CBS Public Meeting-Boston

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ... public involvement and education on decommissioning and the storage of spent nuclear fuel. ... Tierney) and is on the mediation panels for PJM, the Mid-Continent Area Power ...

  3. Agenda CBS Public Meeting-Tempe

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Gholson, Chairman, Timbisha Shoshone Tribe CONSENT- BASED SITING CONSENT-BASED SITING PUBLIC MEETING Phoenix Marriott Tempe at the Buttes 2000 W Westcourt Way Tempe, AZ 85282 June ...

  4. Agenda CBS Public Meeting-Denver

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ... He has consulted with states, Tribes, and citizen groups on repository and consolidated ... utilities subcommittee, 2007-; chair, consumer protection & commercial law work group, ...

  5. Study of the effect of properties of material on vacuum breakdown initiated by laser radiation

    SciTech Connect (OSTI)

    Seleznev, V. P.; Revazov, V. O.

    2015-12-15

    In this work, the effect of various properties of materials on vacuum breakdown initiated by laser radiation is considered. Estimating calculations are performed which show that the material of the target electrode distinctly affects the minimum energy of laser radiation needed for igniting a vacuum spark. The experimental studies carried out confirm the estimating calculations, and a number of materials are revealed which can be arranged in order of increase in the energy needed for the formation of breakdown in vacuum by the impact of a laser pulse.

  6. Preliminary Development of a Work Breakdown Structure (WBS) for Small Modular Reactors (SMRs)

    SciTech Connect (OSTI)

    Harrison, Thomas J.; Moses, Rebecca J.; Flanagan, George F.

    2014-10-01

    In summary, this preliminary WBS serves as an initial basis for the capital cost component of the economic analysis of SMRs. This preliminary WBS comes from the known WBS for existing, large nuclear power plants and develops the methodology for accounting for the anticipated differences between the current large plants and the projected SMR designs.

  7. Breakdown of hierarchical architecture in cellulose during dilute acid pretreatments

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhang, Yan; Inouye, Hideyo; Yang, Lin; Himmel, Michael E.; Tucker, Melvin; Makowski, Lee

    2015-02-28

    Cellulose is an attractive candidate as a feedstock for sustainable bioenergy because of its global abundance. Pretreatment of biomass has significant influence on the chemical availability of cellulose locked in recalcitrant microfibrils. Optimizing pretreatment depends on an understanding of its impact on the microscale and nanoscale molecular architecture. X-ray scattering experiments have been performed on native and pre-treated maize stover and models of cellulose architecture have been derived from these data. Ultra small-angle, very small-angle and small-angle X-ray scattering (USAXS, VSAXS and SAXS) probe three different levels of architectural scale. USAXS and SAXS have been used to study cellulose atmore » two distinct length scales, modeling the fibrils as ~30 Å diameter rods packed into ~0.14 μm diameter bundles. VSAXS is sensitive to structural features at length scales between these two extremes. Detailed analysis of diffraction patterns from untreated and pretreated maize using cylindrical Guinier plots and the derivatives of these plots reveals the presence of substructures within the ~0.14 μm diameter bundles that correspond to grouping of cellulose approximately 30 nm in diameter. These sub-structures are resilient to dilute acid pretreatments but are sensitive to pretreatment when iron sulfate is added. Lastly, these results provide evidence of the hierarchical arrangement of cellulose at three length scales and the evolution of these arrangements during pre-treatments.« less

  8. Breakdown of hierarchical architecture in cellulose during dilute acid pretreatments

    SciTech Connect (OSTI)

    Zhang, Yan; Inouye, Hideyo; Yang, Lin; Himmel, Michael E.; Tucker, Melvin; Makowski, Lee

    2015-02-28

    Cellulose is an attractive candidate as a feedstock for sustainable bioenergy because of its global abundance. Pretreatment of biomass has significant influence on the chemical availability of cellulose locked in recalcitrant microfibrils. Optimizing pretreatment depends on an understanding of its impact on the microscale and nanoscale molecular architecture. X-ray scattering experiments have been performed on native and pre-treated maize stover and models of cellulose architecture have been derived from these data. Ultra small-angle, very small-angle and small-angle X-ray scattering (USAXS, VSAXS and SAXS) probe three different levels of architectural scale. USAXS and SAXS have been used to study cellulose at two distinct length scales, modeling the fibrils as ~30 Å diameter rods packed into ~0.14 μm diameter bundles. VSAXS is sensitive to structural features at length scales between these two extremes. Detailed analysis of diffraction patterns from untreated and pretreated maize using cylindrical Guinier plots and the derivatives of these plots reveals the presence of substructures within the ~0.14 μm diameter bundles that correspond to grouping of cellulose approximately 30 nm in diameter. These sub-structures are resilient to dilute acid pretreatments but are sensitive to pretreatment when iron sulfate is added. Lastly, these results provide evidence of the hierarchical arrangement of cellulose at three length scales and the evolution of these arrangements during pre-treatments.

  9. Transition between breakdown regimes in a temperature-dependent mixture of argon and mercury using 100 kHz excitation

    SciTech Connect (OSTI)

    Sobota, A.; Bos, R. A. J. M. van den; Kroesen, G. [Dept. of Applied Physics, Eindhoven University of Technology, Postbus 513, 5600MB Eindhoven (Netherlands); Manders, F. [Philips Innovative Applications, Steenweg op Gierle 417, B-2300 Turnhout (Belgium)

    2013-01-28

    The paper examines the breakdown process at 100 kHz in a changing temperature-dependent mixture of Ar and Hg and the associated transitions between breakdown regimes. Each measurement series started at 1400 K, 10 bar of Hg, and 0.05% admixture of Ar and finished by natural cooling at room temperature, 150 mbar of Ar, and 0.01% admixture of Hg. The E/N at breakdown as a function of temperature and gas composition was found to have a particular shape with a peak at 600 K, when Hg makes up for 66% of the gaseous mixture and Ar 34%. This peak was found to be an effect of the mixture itself, not the temperature effects or the possible presence of electronegative species. The analysis has shown that at this frequency both streamer and diffuse breakdown can take place, depending on the temperature and gas composition. Streamer discharges during breakdown are present at high temperatures and high Hg pressure, while at room temperature in 150 mbar of Ar the breakdown has a diffuse nature. In between those two cases, the radius of the discharges during breakdown was found to change in a monotonic manner, covering one order of magnitude from the size typical for streamer discharges to a diffuse discharge comparable to the size of the reactor.

  10. Performance and breakdown characteristics of irradiated vertical power GaN P-i-N diodes

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    King, M. P.; Armstrong, A. M.; Dickerson, J. R.; Vizkelethy, G.; Fleming, R. M.; Campbell, J.; Wampler, W. R.; Kizilyalli, I. C.; Bour, D. P.; Aktas, O.; et al

    2015-10-29

    Electrical performance and defect characterization of vertical GaN P-i-N diodes before and after irradiation with 2.5 MeV protons and neutrons is investigated. Devices exhibit increase in specific on-resistance following irradiation with protons and neutrons, indicating displacement damage introduces defects into the p-GaN and n- drift regions of the device that impact on-state device performance. The breakdown voltage of these devices, initially above 1700 V, is observed to decrease only slightly for particle fluence <; 1013 cm-2. Furthermore, the unipolar figure of merit for power devices indicates that while the on-resistance and breakdown voltage degrade with irradiation, vertical GaN P-i-Ns remainmore » superior to the performance of the best available, unirradiated silicon devices and on-par with unirradiated modern SiC-based power devices.« less

  11. Acoustic monitoring method and system in laser-induced optical breakdown (LIOB)

    DOE Patents [OSTI]

    O'Donnell, Matthew; Ye, Jing Yong; Norris, Theodore B.; Baker, Jr., James R.; Balogh, Lajos P.; Milas, Susanne M.; Emelianov, Stanislav Y.; Hollman, Kyle W.

    2008-05-06

    An acoustic monitoring method and system in laser-induced optical breakdown (LIOB) provides information which characterize material which is broken down, microbubbles in the material, and/or the microenvironment of the microbubbles. In one embodiment of the invention, femtosecond laser pulses are focused just inside the surface of a volume of aqueous solution which may include dendrimer nanocomposite (DNC) particles. A tightly focused, high frequency, single-element ultrasonic transducer is positioned such that its focus coincides axially and laterally with this laser focus. When optical breakdown occurs, a microbubble forms and a shock or pressure wave is emitted (i.e., acoustic emission). In addition to this acoustic signal, the microbubble may be actively probed with pulse-echo measurements from the same transducer. After the microbubble forms, received pulse-echo signals have an extra pulse, describing the microbubble location and providing a measure of axial microbubble size. Wavefield plots of successive recordings illustrate the generation, growth, and collapse of microbubbles due to optical breakdown. These same plots can also be used to quantify LIOB thresholds.

  12. Liquid Argon Dielectric Breakdown Studies with the MicroBooNE Purification System

    SciTech Connect (OSTI)

    Acciarri, R.; Carls, B.; James, C.; Johnson, B.; Jostlein, H.; Lockwitz, S.; Lundberg, B.; Raaf, J. L.; Rameika, R.; Rebel, B.; Zeller, G. P.; Zuckerbrot, M.

    2014-11-04

    The proliferation of liquid argon time projection chamber detectors makes the characterization of the dielectric properties of liquid argon a critical task. To improve understanding of these properties, a systematic study of the breakdown electric field in liquid argon was conducted using a dedicated cryostat connected to the MicroBooNE cryogenic system at Fermilab. An electrode sphere-plate geometry was implemented using spheres with diameters of 1.3 mm, 5.0 mm, and 76 mm. The MicroBooNE cryogenic system allowed measurements to be taken at a variety of electronegative contamination levels ranging from a few parts-per-million to tens of parts-per-trillion. The cathode-anode distance was varied from 0.1 mm to 2.5 cm. The results demonstrate a geometric dependence of the electric field strength at breakdown. This study is the first time that the dependence of the breakdown field on stressed cathode area has been shown for liquid argon.

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

    SciTech Connect (OSTI)

    Dolgashev, Valery; Tantawi, Sami; Yeremian, Anahid; Higashi, Yasuo; Spataro, Bruno; /INFN, Rome

    2012-06-25

    Our experiments are directed toward the understanding of the physics of rf breakdown in systems that can be used to accelerate electron beams at {approx}11.4 GHz. The structure geometries have apertures, stored energy per cell, and rf pulse duration close to that of the NLC or CLIC. The breakdown rate is the main parameter that we use to compare rf breakdown behavior for different structures at a given set of rf pulse parameters (pulse shape and peak power) at 60 Hz repetition rate. In our experiments, the typical range of the breakdown rate is from one per few hours to {approx}100 per hour. To date we have tested 29 structures. We consistently found that after the initial conditioning, the behavior of the breakdown rate is reproducible for structures of the same geometry and material, and the breakdown rate dependence on peak magnetic fields is stronger than on peak surface electric fields for structures of different geometries. Below we report the main results from tests of seven structures made from hard copper, soft copper alloys and hard-copper alloys. Additional details on these and other structures will be discussed in future publications.

  14. Dielectric breakdown properties of hot SF{sub 6}/He mixtures predicted from basic data

    SciTech Connect (OSTI)

    Wang, Weizong; State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an Shaanxi 710049 ; Tu, Xin; Mei, Danhua; Rong, Mingzhe

    2013-11-15

    Sulfur hexafluoride (SF{sub 6}) gas has a quite high global warming potential and hence it is required that applying any substitute for SF{sub 6} gas. Much interest in the use of a mixture of helium and SF{sub 6} as arc quenching medium was investigated indicating a higher recovery performance of arc interruption than that of pure SF{sub 6}. It is known that the electrical breakdown in a circuit breaker after arc interruption occurs in a hot gas environment, with a complicated species composition because of the occurrence of dissociation and other reactions. The likelihood of breakdown relies on the electron interactions with all these species. The critical reduced electric field strength (the field at which breakdown can occur, relative to the number density) of hot SF{sub 6}/He mixtures related to the dielectric recovery phase of a high voltage circuit breaker is calculated in the temperature range from 300 K to 3500 K. The critically reduced electric field strength of these mixtures was obtained by balancing electron generation and loss mechanisms. These were evaluated using the electron energy distribution function derived from the Boltzmann transport equation under the two-term approximation. Good agreement was found between calculations for pure hot SF{sub 6} and pure hot He and experimental results and previous calculations. The addition of He to SF{sub 6} was found to decrease the critical reduced electric field strength in the whole temperature range due to a lack of electron impact attachment process for helium regardless its high ionization potential. This indicates that not the behaviour of dielectric strength but possibly the higher energy dissipation capability caused mainly by light mass and high specific heat as well as thermal conductivity of atomic helium contributes most to a higher dielectric recovery performance of arc interruption for SF{sub 6}/He mixtures.

  15. Commercialization of laser-induced breakdown spectroscopy for lead-in-paint inspection

    SciTech Connect (OSTI)

    Myers, Richard A.; Kolodziejski, Noah J.; Squillante, Michael R

    2008-11-01

    A study was undertaken to determine if laser-induced breakdown spectroscopy (LIBS) can be a practical and competitive alternative to x-ray fluorescence (XRF) methods for lead-in-paint inspection. Experiments in the laboratory confirmed that LIBS is suitable for detecting lead in paint at the hazard levels defined by federal agencies. Although we compared speed, function, and cost, fundamental differences between the XRF and LIBS measurements limited our ability to make a quantitative performance comparison. While the LIBS method can achieve the required sensitivity and offers a way to obtain unique information during inspection, the current component costs will likely restrict interest in the method to niche applications.

  16. INVESTIGATION OF BREAKDOWN INDUCED SURFACE DAMAGE ON 805 MHZ PILLBOX CAVITY INTERIOR SURFACES

    SciTech Connect (OSTI)

    Jana, M. R.; Chung, M.; Leonova, M.; Moretti, A.; Tollestrup, A.; Yonehara, K.; Freemire, B.; Torun, Y.; Bowring, D.; Flanagan, G.

    2013-09-25

    The MuCool Test Area (MTA) at Fermilab is a facility to develop the technology required for ionization cooling for a future Muon Collider and/or Neutrino Factory. As part of this research program, we have tested two 805 MHz vacuum RF cavities in a multi-Tesla magnetic field to study the effects of the static magnetic field on the cavity operation. This study gives useful information on field emitters in the cavity, dark current, surface conditioning, breakdown mechanisms and material properties of the cavity. All these factors determine the maximum accelerating gradient in the cavity. This paper discusses the image processing technique for quantitative estimation of spark damage spot distribution on cavity interior surfaces. The distribution is compared with the electric field distribution predicted by a computer code calculation. The local spark density is proportional to probability of surface breakdown and shows a power law dependence on the maximum electric field (E). This E dependence is consistent with the dark current calculated from the Fowler-Nordheim equation.

  17. Gas breakdown mechanism in pulse-modulated asymmetric ratio frequency dielectric barrier discharges

    SciTech Connect (OSTI)

    Wang, Qi; Sun, Jizhong, E-mail: jsun@dlut.edu.cn; Ding, Zhenfeng; Ding, Hongbin; Wang, Dezhen [School of Physics and Optoelectronic Engineering, Dalian University of Technology, Dalian 116023 (China); Nozaki, Tomohiro [Department of Mechanical Sciences and Engineering, Tokyo Institute of Technology, Tokyo 152-8550 (Japan); Wang, Zhanhui [Southwestern Institute of Physics, Chengdu 610041 (China)

    2014-08-15

    The gas breakdown mechanisms, especially the roles of metastable species in atmospheric pressure pulse-modulated ratio frequency barrier discharges with co-axial cylindrical electrodes, were studied numerically using a one dimensional self-consistent fluid model. Simulation results showed that in low duty cycle cases, the electrons generated from the channels associated with metastable species played a more important role in initializing next breakdown than the direct ionization of helium atoms of electronic grounded states by electron-impact. In order to quantitatively evaluate the contribution to the discharge by the metastables, we defined a characteristic time and examined how the value varied with the gap distance and the electrode asymmetry. The results indicated that the lifetime of the metastable species (including He*and He{sub 2}{sup *}) was much longer than that of the pulse-on period and as effective sources of producing electrons they lasted over a period up to millisecond. When the ratio of the outer radius to the inner radius of the cylindrical electrodes was far bigger than one, it was found that the metastables distributed mainly in a cylindrical region around the inner electrode. When the ratio decreased as the inner electrode moved outward, the density of metastables in the discharge region near the outer electrode became gradually noticeable. As the discharging gap continued to decrease, the two hill-shaped distributions gradually merged to one big hill. When the discharge spacing was fixed, asymmetric electrodes facilitated the discharge.

  18. Spectrographic temperature measurement of a high power breakdown arc in a high pressure gas switch

    SciTech Connect (OSTI)

    Yeckel, Christopher; Curry, Randy

    2011-09-15

    A procedure for obtaining an approximate temperature value of conducting plasma generated during self-break closure of a RIMFIRE gas switch is described. The plasma is in the form of a breakdown arc which conducts approximately 12 kJ of energy in 1 {mu}s. A spectrographic analysis of the trigger-section of the 6-MV RIMFIRE laser triggered gas switch used in Sandia National Laboratory's ''Z-Machine'' has been made. It is assumed that the breakdown plasma has sufficiently approached local thermodynamic equilibrium allowing a black-body temperature model to be applied. This model allows the plasma temperature and radiated power to be approximated. The gas dielectric used in these tests was pressurized SF{sub 6}. The electrode gap is set at 4.59 cm for each test. The electrode material is stainless steel and insulator material is poly(methyl methacrylate). A spectrum range from 220 to 550 nanometers has been observed and calibrated using two spectral irradiance lamps and three spectrograph gratings. The approximate plasma temperature is reported.

  19. Laser-induced fluorescence-cued, laser-induced breakdown spectroscopy biological-agent detection

    SciTech Connect (OSTI)

    Hybl, John D.; Tysk, Shane M.; Berry, Shaun R.; Jordan, Michael P

    2006-12-01

    Methods for accurately characterizing aerosols are required for detecting biological warfare agents. Currently, fluorescence-based biological agent sensors provide adequate detection sensitivity but suffer from high false-alarm rates. Combining single-particle fluorescence analysis with laser-induced breakdown spectroscopy (LIBS) provides additional discrimination and potentially reduces false-alarm rates. A transportable UV laser-induced fluorescence-cued LIBS test bed has been developed and used to evaluate the utility of LIBS for biological-agent detection. Analysis of these data indicates that LIBS adds discrimination capability to fluorescence-based biological-agent detectors.However, the data also show that LIBS signatures of biological agent simulants are affected by washing. This may limit the specificity of LIBS and narrow the scope of its applicability in biological-agent detection.

  20. Spectral selective radio frequency emissions from laser induced breakdown of target materials

    SciTech Connect (OSTI)

    Vinoth Kumar, L.; Manikanta, E.; Leela, Ch.; Prem Kiran, P.

    2014-08-11

    The radio frequency emissions scanned over broad spectral range (30 MHz–1 GHz) from single shot nanosecond (7 ns) and picosecond (30 ps) laser induced breakdown (LIB) of different target materials (atmospheric air, aluminum, and copper) are presented. The dominant emissions from ns-LIB, compared to those from the ps-LIB, indicate the presence and importance of atomic and molecular clusters in the plasma. The dynamics of laser pulse-matter interaction and the properties of the target materials were found to play an important role in determining the plasma parameters which subsequently determine the emissions. Thus, with a particular laser and target material, the emissions were observed to be spectral selective. The radiation detection capability was observed to be relatively higher, when the polarization of the input laser and the antenna is same.

  1. Two-phase mixed media dielectric with macro dielectric beads for enhancing resistivity and breakdown strength

    DOE Patents [OSTI]

    Falabella, Steven; Meyer, Glenn A; Tang, Vincent; Guethlein, Gary

    2014-06-10

    A two-phase mixed media insulator having a dielectric fluid filling the interstices between macro-sized dielectric beads packed into a confined volume, so that the packed dielectric beads inhibit electro-hydrodynamically driven current flows of the dielectric liquid and thereby increase the resistivity and breakdown strength of the two-phase insulator over the dielectric liquid alone. In addition, an electrical apparatus incorporates the two-phase mixed media insulator to insulate between electrical components of different electrical potentials. And a method of electrically insulating between electrical components of different electrical potentials fills a confined volume between the electrical components with the two-phase dielectric composite, so that the macro dielectric beads are packed in the confined volume and interstices formed between the macro dielectric beads are filled with the dielectric liquid.

  2. Remote Compositional Analysis of Spent-Fuel Residues Using Laser-Induced Breakdown Spectroscopy

    SciTech Connect (OSTI)

    Whitehouse, A. I.; Young, J.; Evans, C. P.; Brown, A.; Simpson, A.; Franco, J.

    2003-02-26

    We report on the application of a novel technique known as Laser-Induced Breakdown Spectroscopy (LIBS) for remotely detecting and characterizing the elemental composition of highly radioactive materials including spent-fuel residues and High-Level Waste (HLW). Within the UK nuclear industry, LIBS has been demonstrated to offer a convenient alternative to sampling and laboratory analysis of a wide range of materials irrespective of the activity of the material or the ambient radiation levels. Proven applications of this technology include in-situ compositional analysis of nuclear reactor components, remote detection and characterization of vitrified HLW and remote compositional analysis of highly-active gross contamination within a spent-fuel reprocessing plant.

  3. Nonlinear theory of drift-cyclotron kinetics and the possible breakdown of gyro-kinetics

    SciTech Connect (OSTI)

    Waltz, R. E.; Deng Zhao

    2013-01-15

    A nonlinear theory of drift-cyclotron kinetics (termed cyclo-kinetics here) is formulated to test the breakdown of the gyro-kinetic approximations. Six dimensional cyclo-kinetics can be regarded as an extension of five dimensional gyro-kinetics to include high-frequency cyclotron waves, which can interrupt the low-frequency gyro-averaging in the (sixth velocity grid) gyro-phase angle. Nonlinear cyclo-kinetics has no limit on the amplitude of the perturbations. Formally, there is no gyro-averaging when all cyclotron (gyro-phase angle) harmonics of the perturbed distribution function (delta-f) are retained. Retaining only the (low frequency) zeroth cyclotron harmonic in cyclo-kinetics recovers both linear and nonlinear gyro-kinetics. Simple recipes are given for converting continuum nonlinear delta-f gyro-kinetic transport simulation codes to cyclo-kinetics codes by retaining (at least some) higher cyclotron harmonics.

  4. Laser-induced breakdown spectroscopy measurement in methane and biodiesel flames using an ungated detector

    SciTech Connect (OSTI)

    Eseller, Kemal E.; Yueh, Fang Y.; Singh, Jagdish P

    2008-11-01

    Laser-induced breakdown spectroscopy (LIBS) has been applied to measure the equivalence ratio of CH4/air flames using gated detection. In this work, we have developed an ungated, miniature LIBS-based sensor for studying CH4/air and biodiesel flames. We have used this sensor to characterize the biodiesel flame. LIBS spectra of biodiesel flames were recorded with different ethanol concentrations in the biodiesel and also at different axial locations within the flame. The sensor performance was evaluated with a CH4/air flame. LIBS signals of N, O, and H from a CH4/air flame were used to determine the equivalence ratio. A linear relationship between the intensity ratio of H and O lines and the calculated equivalence ratio were obtained with this sensor.

  5. Fiber optic laser-induced breakdown spectroscopy sensor for molten material analysis

    DOE Patents [OSTI]

    Zhang, Hansheng; Rai, Awadesh K.; Singh, Jagdish P.; Yueh, Fang-Yu

    2004-07-13

    A fiber optic laser-induced breakdown spectroscopy (LIBS) sensor, including a laser light source, a harmonic separator for directing the laser light, a dichroic mirror for reflecting the laser light, a coupling lens for coupling the laser light at an input of a multimode optical fiber, a connector for coupling the laser light from an output of the multimode optical fiber to an input of a high temperature holder, such as a holder made of stainless steel, and a detector portion for receiving emission signal and analyzing LIBS intensities. In one variation, the multimode optical fiber has silica core and silica cladding. The holder includes optical lenses for collimating and focusing the laser light in a molten alloy to produce a plasma, and for collecting and transmitting an emission signal to the multimode optical fiber.

  6. Corrosion potential and breakdown potential distributions for stainless steels in seawater

    SciTech Connect (OSTI)

    Salvago, G.; Fumagalli, G.; Taccani, G.

    1996-10-01

    The definition of corrosion potential was examined in relation to stainless steels in seawater. The experimental investigation was extended to include austenitic, ferritic and superaustenitic stainless steels. From each material, between 30 and 100 specimens were taken for a total of over 1,000. Measurements of the corrosion potentials of specimens of different sizes and under different exposure conditions were carried out as well as those of the breakdown potentials in cells that could contain up to 100 specimens and also measurements on galvanic couples. All the tests were performed with natural seawater in experiments lasting over a period from 1 to 18 months. The results obtained have shown that: The corrosion potentials of stainless steel in seawater are dispersed in a wide range; The dispersion is not only attributable to fluctuations of the environmental characteristics or to differences between the specimens of the same steel but is an intrinsic characteristic of the specific corrosion system; The distribution of the corrosion potentials measured on the same specimen at different times is similar to the distribution of the corrosion potentials of different specimens, of the same sample, measured at the same time. The distribution of corrosion potentials, like the distribution of breakdown potentials, is affected by the size of the specimens, the exposure conditions and whether forms of localized corrosions are present. A peculiar role in the corrosion potential distribution appears to be played by the galvanic coupling between the surface of the stainless steel and predetermined non-uniform areas such as the edges of the specimens or not predetermined like the areas of development of the localized attack or fluctuating in space and time like the areas of potential or incipient attack.

  7. Understanding the breakdown of classic two-phase theory and spray atomization at engine-relevant conditions

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Dahms, Rainer N.

    2016-04-26

    We present a generalized framework for multi-component liquid injections to understand and predict the breakdown of classic two-phase theory and spray atomization at engine-relevant conditions. The analysis focuses on the thermodynamic structure and the immiscibility state of representative gas-liquid interfaces. The most modern form of Helmholtz energy mixture state equation is utilized which exhibits a unique and physically-consistent behavior over the entire two-phase regime of fluid densities. It is combined with generalized models for non-linear Gradient Theory and for liquid injections to quantify multi-component two-phase interface structures in global thermal equilibrium. Then, the Helmholtz free energy is minimized which determinesmore » the interfacial species distribution as a consequence. This minimal free energy state is demonstrated to validate the underlying assumptions of classic two-phase theory and spray atomization. However, under certain engine-relevant conditions for which corroborating experimental data is presented, this requirement for interfacial thermal equilibrium becomes unsustainable. A rigorously derived probability density function quantifies the ability of the interface to develop internal spatial temperature gradients in the presence of significant temperature differences between injected liquid and ambient gas. Then, the interface can no longer be viewed as an isolated system at minimal free energy. Instead, the interfacial dynamics become intimately connected to those of the separated homogeneous phases. Hence, the interface transitions toward a state in local equilibrium whereupon it becomes a dense-fluid mixing layer. A new conceptual view of a transitional liquid injection process emerges from a transition time scale analysis. Close to the nozzle exit, the two-phase interface still remains largely intact and more classic two-phase processes prevail as a consequence. Further downstream, however, the transition to dense- fluid

  8. Investigation of historical metal objects using Laser Induced Breakdown Spectroscopy (LIBS) technique

    SciTech Connect (OSTI)

    Abdel-Kareem, O.; Ghoneim, M.; Harith, M. A.

    2011-09-22

    Analysis of metal objects is a necessary step for establishing an appropriate conservation treatment of an object or to follow up the application's result of the suggested treatments. The main considerations on selecting a method that can be used in investigation and analysis of metal objects are based on the diagnostic power, representative sampling, reproducibility, destructive nature/invasiveness of analysis and accessibility to the appropriate instrument. This study aims at evaluating the usefulness of the use of Laser Induced Breakdown Spectroscopy (LIBS) Technique for analysis of historical metal objects. In this study various historical metal objects collected from different museums and excavations in Egypt were investigated using (LIBS) technique. For evaluating usefulness of the suggested analytical protocol of this technique, the same investigated metal objects were investigated by other methods such as Scanning Electron Microscope with energy-dispersive x-ray analyzer (SEM-EDX) and X-ray Diffraction (XRD). This study confirms that Laser Induced Breakdown Spectroscopy (LIBS) Technique is considered very useful technique that can be used safely for investigating historical metal objects. LIBS analysis can quickly provide information on the qualitative and semi-quantitative elemental content of different metal objects and their characterization and classification. It is practically non-destructive technique with the critical advantage of being applicable in situ, thereby avoiding sampling and sample preparations. It is can be dependable, satisfactory and effective method for low cost study of archaeological and historical metals. But we have to take into consideration that the corrosion of metal leads to material alteration and possible loss of certain metals in the form of soluble salts. Certain corrosion products are known to leach out of the object and therefore, their low content does not necessarily reflect the composition of the metal at the time of

  9. Laser-induced breakdown and damage generation by nonlinear frequency conversion in ferroelectric crystals: Experiment and theory

    SciTech Connect (OSTI)

    Louchev, Oleg A.; Saito, Norihito; Wada, Satoshi; Hatano, Hideki; Kitamura, Kenji

    2013-11-28

    Using our experimental data for ns pulsed second harmonic generation (SHG) by periodically poled stoichiometric LiTaO{sub 3} (PPSLT) crystals, we consider in detail the mechanism underlying laser-induced damage in ferroelectric crystals. This mechanism involves generation and heating of free electrons, providing an effective kinetic pathway for electric breakdown and crystal damage in ns pulsed operation via combined two-photon absorption (TPA) and induced pyroelectric field. In particular, a temperature increase in the lattice of ≈1 K induced initially by ns SHG and TPA at the rear of operating PPSLT crystal is found to induce a gradient of spontaneous polarization generating a pyroelectric field of ≈10 kV/cm, accelerating free electrons generated by TPA to an energy of ≈10 eV, followed by impact ionization and crystal damage. Under the damage threshold for ns operation, the impact ionization does not lead to the avalanche-like increase of free electron density, in contrast to the case of shorter ps and fs pulses. However, the total number of collisions by free electrons, ≈10{sup 18} cm{sup −3} (generated during the pulse and accelerated to the energy of ≈10 eV), can produce widespread structural defects, which by entrapping electrons dramatically increase linear absorption for both harmonics in subsequent pulses, creating a positive feedback for crystal lattice heating, pyroelectric field and crystal damage. Under pulse repetition, defect generation starting from the rear of the crystal can propagate towards its center and front side producing damage tracks along the laser beam and stopping SHG. Theoretical analysis leads to numerical estimates and analytical approximation for the threshold laser fluence for onset of this damage mechanism, which agree well with our (i) experiments for the input 1064 nm radiation in 6.8 kHz pulsed SHG by PPSLT crystal, (ii) pulsed low frequency 532 nm radiation transmission experiments, and also (iii) with the data

  10. Spectral Analysis of Rare Earth Elements using Laser-Induced Breakdown Spectroscopy

    SciTech Connect (OSTI)

    Martin, Madhavi Z; Fox, Dr. Richard V; Miziolek, Andrzej W; DeLucia, Frank C; Andre, Nicolas O

    2015-01-01

    There is growing interest in rapid analysis of rare earth elements (REEs) both due to the need to find new natural sources to satisfy increased demand in their use in various electronic devices, as well as the fact that they are used to estimate actinide masses for nuclear safeguards and nonproliferation. Laser-Induced Breakdown Spectroscopy (LIBS) appears to be a particularly well-suited spectroscopy-based technology to rapidly and accurately analyze the REEs in various matrices at low concentration levels (parts-per-million). Although LIBS spectra of REEs have been reported for a number of years, further work is still necessary in order to be able to quantify the concentrations of various REEs in real-world complex samples. LIBS offers advantages over conventional solution-based radiochemistry in terms of cost, analytical turnaround, waste generation, personnel dose, and contamination risk. Rare earth elements of commercial interest are found in the following three matrix groups: 1) raw ores and unrefined materials, 2) as components in refined products such as magnets, lighting phosphors, consumer electronics (which are mostly magnets and phosphors), catalysts, batteries, etc., and 3) waste/recyclable materials (aka e-waste). LIBS spectra for REEs such as Gd, Nd, and Sm found in rare earth magnets are presented.

  11. Spectral Analysis of Rare Earth Elements using Laser-Induced Breakdown Spectroscopy

    SciTech Connect (OSTI)

    Martin, Madhavi Z; Fox, Dr. Richard V; Miziolek, Andrzej W; DeLucia, Frank C; Andre, Nicolas O

    2015-01-01

    There is growing interest in rapid analysis of rare earth elements (REEs) both due to the need to find new natural sources to satisfy increased demand in their use in various electronic devices, as well as the fact that they are used to estimate actinide masses for nuclear safeguards and nonproliferation. Laser-Induced Breakdown Spectroscopy (LIBS) appears to be a particularly well-suited spectroscopy-based technology to rapidly and accurately analyze the REEs in various matrices at low concentration levels (parts-per-million). Although LIBS spectra of REEs have been reported for a number of years, further work is still necessary in order to be able to quantify the concentrations of various REEs in realworld complex samples. LIBS offers advantages over conventional solution-based radiochemistry in terms of cost, analytical turnaround, waste generation, personnel dose, and contamination risk. Rare earth elements of commercial interest are found in the following three matrix groups: 1) raw ores and unrefined materials, 2) as components in refined products such as magnets, lighting phosphors, consumer electronics (which are mostly magnets and phosphors), catalysts, batteries, etc., and 3) waste/recyclable materials (aka e-waste). LIBS spectra for REEs such as Gd, Nd, and Sm found in rare earth magnets are presented.

  12. Spectral Analysis of Rare Earth Elements using Laser-Induced Breakdown Spectroscopy

    SciTech Connect (OSTI)

    Madhavi Z. Martin; Robert V. Fox; Andrzej W. Miziolek; Frank C. DeLucia, Jr.; Nicolas Andre

    2001-05-01

    There is growing interest in rapid analysis of rare earth elements (REEs) both due to the need to find new natural sources to satisfy increased demand in their use in various electronic devices, as well as the fact that they are used to estimate actinide masses for nuclear safeguards and nonproliferation. Laser-Induced Breakdown Spectroscopy (LIBS) appears to be a particularly well-suited spectroscopy-based technology to rapidly and accurately analyze the REEs in various matrices at low concentration levels (parts-per-million). Although LIBS spectra of REEs have been reported for a number of years, further work is still necessary in order to be able to quantify the concentrations of various REEs in realworld complex samples. LIBS offers advantages over conventional solution-based radiochemistry in terms of cost, analytical turnaround, waste generation, personnel dose, and contamination risk. Rare earth elements of commercial interest are found in the following three matrix groups: 1) raw ores and unrefined materials, 2) as components in refined products such as magnets, lighting phosphors, consumer electronics (which are mostly magnets and phosphors), catalysts, batteries, etc., and 3) waste/recyclable materials (aka e-waste). LIBS spectra for REEs such as Gd, Nd, and Sm found in rare earth magnets are presented.

  13. Practical high resolution detection method for laser-induced breakdown spectroscopy

    SciTech Connect (OSTI)

    Andrew J. Effenberger Jr; Jill R. Scott

    2012-02-01

    A Fabry-Perot etalon was coupled to a Czerny-Turner spectrometer to acquire high-resolution measurements in laser-induced breakdown spectroscopy (LIBS). The spectrometer was built using an inexpensive etalon coupled to a standard 0.5-m imaging spectrometer. The Hg emission doublet at 313.2 nm was used to evaluate instrument performance because it has a splitting of 29 pm. The 313.2 nm doublet was chosen due to the similar splitting seen in isotope splitting from uranium at 424.437 nm, which is 25 pm. The Hg doublet was easily resolved from a continuous source Hg-lamp with a 2 s acquisition. The doublet was also resolved in LIBS spectra of cinnabar (HgS) from the accumulation of 600 laser shots at rate of 10 Hz, or 1 min, under a helium atmosphere. In addition to observed spitting of the 313.2 nm Hg doublet, the FWHM of the 313.1844 nm line from the doublet is reported at varying He atmospheric pressures. The high performance, low cost, and compact footprint makes this system highly competitive with 2-m double pass Czerny-Turner spectrometers.

  14. Corrosion, passivity and breakdown of alloys used in high energy density batteries: Final report

    SciTech Connect (OSTI)

    Kruger, J.

    1987-10-01

    The objective of this research is to further the understanding of the passivity of metals and alloys in non-aqueous and mixed solvents. There is a lack of data in this area, despite its importance to applications such as the construction materials for high energy density batteries. There have been a number of corrosion-related problems reported in the construction materials of such batteries. As demands for longevity for these batteries increase, problems associated with corrosion will become increasingly important. This work is concerned with analyzing the nature, mode of formation, and mode of breakdown of passive films that exist on alloys in non-aqueous and mixed solvents. Work during Year I has concentrated upon generating cyclic voltammograms and potentiodynamic curves as baseline data on Au and Armco Fe in water/propylene carbonate mixtures. In addition, Scanning Electron Microscopy has been performed in order to characterize the attack observed and to correlate it to the electrochemical parameters measured. 3 refs., 15 figs.

  15. Quantification of rare earth elements using laser-induced breakdown spectroscopy

    SciTech Connect (OSTI)

    Martin, Madhavi; Martin, Rodger C.; Allman, Steve; Brice, Deanne; Wymore, Ann; Andre, Nicolas

    2015-10-21

    In this paper, a study of the optical emission as a function of concentration of laser-ablated yttrium (Y) and of six rare earth elements, europium (Eu), gadolinium (Gd), lanthanum (La), praseodymium (Pr), neodymium (Nd), and samarium (Sm), has been evaluated using the laser-induced breakdown spectroscopy (LIBS) technique. Statistical methodology using multivariate analysis has been used to obtain the sampling errors, coefficient of regression, calibration, and cross-validation of measurements as they relate to the LIBS analysis in graphite-matrix pellets that were doped with elements at several concentrations. Each element (in oxide form) was mixed in the graphite matrix in percentages ranging from 1% to 50% by weight and the LIBS spectra obtained for each composition as well as for pure oxide samples. Finally, a single pellet was mixed with all the elements in equal oxide masses to determine if we can identify the elemental peaks in a mixed pellet. This dataset is relevant for future application to studies of fission product content and distribution in irradiated nuclear fuels. These results demonstrate that LIBS technique is inherently well suited for the future challenge of in situ analysis of nuclear materials. Finally, these studies also show that LIBS spectral analysis using statistical methodology can provide quantitative results and suggest an approach in future to the far more challenging multielemental analysis of ~ 20 primary elements in high-burnup nuclear reactor fuel.

  16. Quantification of rare earth elements using laser-induced breakdown spectroscopy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Martin, Madhavi; Martin, Rodger C.; Allman, Steve; Brice, Deanne; Wymore, Ann; Andre, Nicolas

    2015-10-21

    In this paper, a study of the optical emission as a function of concentration of laser-ablated yttrium (Y) and of six rare earth elements, europium (Eu), gadolinium (Gd), lanthanum (La), praseodymium (Pr), neodymium (Nd), and samarium (Sm), has been evaluated using the laser-induced breakdown spectroscopy (LIBS) technique. Statistical methodology using multivariate analysis has been used to obtain the sampling errors, coefficient of regression, calibration, and cross-validation of measurements as they relate to the LIBS analysis in graphite-matrix pellets that were doped with elements at several concentrations. Each element (in oxide form) was mixed in the graphite matrix in percentages rangingmore » from 1% to 50% by weight and the LIBS spectra obtained for each composition as well as for pure oxide samples. Finally, a single pellet was mixed with all the elements in equal oxide masses to determine if we can identify the elemental peaks in a mixed pellet. This dataset is relevant for future application to studies of fission product content and distribution in irradiated nuclear fuels. These results demonstrate that LIBS technique is inherently well suited for the future challenge of in situ analysis of nuclear materials. Finally, these studies also show that LIBS spectral analysis using statistical methodology can provide quantitative results and suggest an approach in future to the far more challenging multielemental analysis of ~ 20 primary elements in high-burnup nuclear reactor fuel.« less

  17. Exploring laser-induced breakdown spectroscopy for nuclear materials analysis and in-situ applications

    SciTech Connect (OSTI)

    Martin, Madhavi Z; Allman, Steve L; Brice, Deanne Jane; Martin, Rodger Carl; Andre, Nicolas O

    2012-01-01

    Laser-induced breakdown spectroscopy (LIBS) has been used to determine the limits of detection of strontium (Sr) and cesium (Cs), common nuclear fission products. Additionally, detection limits were determined for cerium (Ce), often used as a surrogate for radioactive plutonium in laboratory studies. Results were obtained using a laboratory instrument with a Nd:YAG laser at fundamental wavelength of 1064 nm, frequency doubled to 532 nm with energy of 50 mJ/pulse. The data was compared for different concentrations of Sr and Ce dispersed in a CaCO3 (white) and carbon (black) matrix. We have addressed the sampling errors, limits of detection, reproducibility, and accuracy of measurements as they relate to multivariate analysis in pellets that were doped with the different elements at various concentrations. These results demonstrate that LIBS technique is inherently well suited for in situ analysis of nuclear materials in hot cells. Three key advantages are evident: (1) small samples (mg) can be evaluated; (2) nuclear materials can be analyzed with minimal sample preparation; and (3) samples can be remotely analyzed very rapidly (ms-seconds). Our studies also show that the methods can be made quantitative. Very robust multivariate models have been used to provide quantitative measurement and statistical evaluation of complex materials derived from our previous research on wood and soil samples.

  18. Fragmentation of fast Josephson vortices and breakdown of ordered states by moving topological defects

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Sheikhzada, Ahmad; Gurevich, Alex

    2015-12-07

    Topological defects such as vortices, dislocations or domain walls define many important effects in superconductivity, superfluidity, magnetism, liquid crystals, and plasticity of solids. Here we address the breakdown of the topologically-protected stability of such defects driven by strong external forces. We focus on Josephson vortices that appear at planar weak links of suppressed superconductivity which have attracted much attention for electronic applications, new sources of THz radiation, and low-dissipative computing. Our numerical simulations show that a rapidly moving vortex driven by a constant current becomes unstable with respect to generation of vortex-antivortex pairs caused by Cherenkov radiation. As a result,more » vortices and antivortices become spatially separated and accumulate continuously on the opposite sides of an expanding dissipative domain. This effect is most pronounced in thin film edge Josephson junctions at low temperatures where a single vortex can switch the whole junction into a resistive state at currents well below the Josephson critical current. In conclusion, our work gives a new insight into instability of a moving topological defect which destroys global long-range order in a way that is remarkably similar to the crack propagation in solids.« less

  19. Determination of a brass alloy concentration composition using calibration-free laser-induced breakdown spectroscopy

    SciTech Connect (OSTI)

    Achouri, M.; Baba-Hamed, T.; Beldjilali, S. A. Belasri, A.

    2015-09-15

    Laser-induced breakdown spectroscopy (LIBS) is a technique that can provide qualitative and quantitative measurements of the characteristics of irradiated metals. In the present work, we have calculated the parameters of the plasma produced from a brass alloy sample under the action of a pulsed Nd: YAG laser operating at 1064 nm. The emission lines of copper atoms (Cu I), zinc atoms (Zn I), and lead atoms (Pb I), which are elements of a brass alloy composition, were used to investigate the parameters of the brass plasma. The spectral profiles of Cu, Zn, and Pb lines have been used to extract the electron temperature and density of the brass alloy plasma. The characteristics of Cu, Zn, and Pb were determined quantatively by the calibration-free LIBS (CF-LIBS) method considering for accurate analysis that the laser-induced ablated plasma is optically thin in local thermodynamic equilibrium conditions and the plasma ablation is stoichiometric. The Boltzmann plot method was used to evaluate the plasma temperature, and the Stark broadened profiles were used to determine the electron density. An algorithm based on the experimentally measured values of the intensity of spectral lines and the basic laws of plasma physics was developed for the determination of Cu, Zn, and Pb concentrations in the brass sample. The concentrations C{sub CF-LIBS} calculated by CF-LIBS and the certified concentrations C{sub certified} were very close.

  20. Fragmentation of fast Josephson vortices and breakdown of ordered states by moving topological defects

    SciTech Connect (OSTI)

    Sheikhzada, Ahmad; Gurevich, Alex

    2015-12-07

    Topological defects such as vortices, dislocations or domain walls define many important effects in superconductivity, superfluidity, magnetism, liquid crystals, and plasticity of solids. Here we address the breakdown of the topologically-protected stability of such defects driven by strong external forces. We focus on Josephson vortices that appear at planar weak links of suppressed superconductivity which have attracted much attention for electronic applications, new sources of THz radiation, and low-dissipative computing. Our numerical simulations show that a rapidly moving vortex driven by a constant current becomes unstable with respect to generation of vortex-antivortex pairs caused by Cherenkov radiation. As a result, vortices and antivortices become spatially separated and accumulate continuously on the opposite sides of an expanding dissipative domain. This effect is most pronounced in thin film edge Josephson junctions at low temperatures where a single vortex can switch the whole junction into a resistive state at currents well below the Josephson critical current. In conclusion, our work gives a new insight into instability of a moving topological defect which destroys global long-range order in a way that is remarkably similar to the crack propagation in solids.

  1. Temperature effect on laser-induced breakdown spectroscopy spectra of molten and solid salts

    SciTech Connect (OSTI)

    Cynthia Hanson; Supathorn Phongikaroon; Jill R. Scott

    2014-07-01

    Laser-induced breakdown spectroscopy (LIBS) has been investigated as a potential analytical tool to improve operations and safeguards for electrorefiners, such as those used in processing spent nuclear fuel. This study set out to better understand the effect of sample temperature and physical state on LIBS spectra of molten and solid salts by building calibration curves of cerium and assessing self-absorption, plasma temperature, electron density, and local thermal equilibrium (LTE). Samples were composed of a LiCl–KCl eutectic salt, an internal standard of MnCl2, and varying concentrations of CeCl3 (0.1, 0.3, 0.5, 0.8, and 1.0 wt.% Ce) under different temperatures (773, 723, 673, 623, and 573 K). Analysis of salts in their molten form is preferred as plasma plumes from molten samples experienced less self-absorption, less variability in plasma temperature, and higher clearance of the minimum electron density required for local thermal equilibrium. These differences are attributed to plasma dynamics as a result of phase changes. Spectral reproducibility was also better in the molten state due to sample homogeneity.

  2. Rapid Analysis of Ash Composition Using Laser-Induced Breakdown Spectroscopy (LIBS)

    SciTech Connect (OSTI)

    Tyler L. Westover

    2013-01-01

    Inorganic compounds are known to be problematic in the thermochemical conversion of biomass to syngas and ultimately hydrocarbon fuels. The elements Si, K, Ca, Na, S, P, Cl, Mg, Fe, and Al are particularly problematic and are known to influence reaction pathways, contribute to fouling and corrosion, poison catalysts, and impact waste streams. Substantial quantities of inorganic species can be entrained in the bark of trees during harvest operations. Herbaceous feedstocks often have even greater quantities of inorganic constituents, which can account for as much as one-fifth of the total dry matter. Current methodologies to measure the concentrations of these elements, such as inductively coupled plasma-optical emission spectrometry/mass spectrometry (ICP-OES/MS) are expensive in time and reagents. This study demonstrates that a new methodology employing laser-induced breakdown spectroscopy (LIBS) can rapidly and accurately analyze the inorganic constituents in a wide range of biomass materials, including both woody and herbaceous examples. This technique requires little or no sample preparation, does not consume any reagents, and the analytical data is available immediately. In addition to comparing LIBS data with the results from ICP-OES methods, this work also includes discussions of sample preparation techniques, calibration curves for interpreting LIBS spectra, minimum detection limits, and the use of internal standards and standard reference materials.

  3. High-Resolution Laser-Induced Breakdown Spectroscopy used in Homeland Security and Forensic Applications

    SciTech Connect (OSTI)

    Martin, Madhavi Z; Wullschleger, Stan D; Vass, Arpad Alexander; Martin, Rodger Carl; Grissino-Mayer, Henri

    2006-01-01

    The technique of laser-induced breakdown spectroscopy (LIBS) to detect elements for a variety of homeland security applications such as nuclear materials identification and inventory,and forensic applications has been demonstrated. For nuclear materials applications, we detected and profiled metals in coatings that were used to encapsulate nuclear fuel. Multivariate analysis has been successfully employed in the quantification of elements present in treated wood and engineered wood composites. These examples demonstrate that LIBS-based techniques are inherently well suited for diverse environmental applications related to homeland security. Three key advantages are evident: (1) small samples (mg) are sufficient; (2) samples can be analyzed by LIBS very rapidly, and (3) biological materials such as human and animal bones and wood can be analyzed with minimal sample preparation. For forensic applications they have used LIBS to determine differences in animal and human bones. They have also applied this technique in the determination of counterfeit and non-counterfeit currency. They recently applied LIBS in helping to solve a murder case.

  4. Electrical breakdown at low pressure in the presence of a weak magnetic field

    SciTech Connect (OSTI)

    Alport, M.J.; Antoniades, J.A.; Boyd, D.A.; Greaves, R.G.; Ellis, R.F. )

    1990-05-01

    Electron trapping in crossed electric and magnetic fields is an important mechanism by which electrical discharges can develop in low pressure gases. The authors report observations of discharges produced by this mechanism around a spherical anode in two space simulation chambers, namely the Space Plasma Interaction Experiment (SPIE) at the University of Maryland, and the NASA-Lewis B-2 chamber. They have identified two types of discharges in these experiments. In the B-2 chamber, the breakdown takes the form of a runaway dischage with spherical topology, limited only by the ability of the power supply to provide the current. In the SPIE chamber this type of discharge also occurs, in addition to a low current toroidal discharge which is observed at higher magnetic fields. They present measurements of both types of discharge and show how the trapping effect of the magnetic field together with secondary electron emission by high energy ion bombardment of the chamber walls may initiate and sustains these discharges.

  5. Preliminary design of laser-induced breakdown spectroscopy for proto-Material Plasma Exposure eXperiment

    SciTech Connect (OSTI)

    Shaw, G.; Martin, M. Z.; Martin, R.; Biewer, T. M.

    2014-11-15

    Laser-induced breakdown spectroscopy (LIBS) is a technique for measuring surface matter composition. LIBS is performed by focusing laser radiation onto a target surface, ablating the surface, forming a plasma, and analyzing the light produced. LIBS surface analysis is a possible diagnostic for characterizing plasma-facing materials in ITER. Oak Ridge National Laboratory has enabled the initial installation of a laser-induced breakdown spectroscopy diagnostic on the prototype Material-Plasma Exposure eXperiment (Proto-MPEX), which strives to mimic the conditions found at the surface of the ITER divertor. This paper will discuss the LIBS implementation on Proto-MPEX, preliminary design of the fiber optic LIBS collection probe, and the expected results.

  6. Performance and breakdown characteristics of irradiated vertical power GaN P-i-N diodes

    SciTech Connect (OSTI)

    King, M. P.; Armstrong, A. M.; Dickerson, J. R.; Vizkelethy, G.; Fleming, R. M.; Campbell, J.; Wampler, W. R.; Kizilyalli, I. C.; Bour, D. P.; Aktas, O.; Nie, H.; Disney, D.; Wierer, Jr., J.; Allerman, A. A.; Moseley, M. W.; Kaplar, R. J.

    2015-10-29

    Electrical performance and defect characterization of vertical GaN P-i-N diodes before and after irradiation with 2.5 MeV protons and neutrons is investigated. Devices exhibit increase in specific on-resistance following irradiation with protons and neutrons, indicating displacement damage introduces defects into the p-GaN and n- drift regions of the device that impact on-state device performance. The breakdown voltage of these devices, initially above 1700 V, is observed to decrease only slightly for particle fluence <; 1013 cm-2. Furthermore, the unipolar figure of merit for power devices indicates that while the on-resistance and breakdown voltage degrade with irradiation, vertical GaN P-i-Ns remain superior to the performance of the best available, unirradiated silicon devices and on-par with unirradiated modern SiC-based power devices.

  7. On-clip high frequency reliability and failure test structures

    DOE Patents [OSTI]

    Snyder, E.S.; Campbell, D.V.

    1997-04-29

    Self-stressing test structures for realistic high frequency reliability characterizations. An on-chip high frequency oscillator, controlled by DC signals from off-chip, provides a range of high frequency pulses to test structures. The test structures provide information with regard to a variety of reliability failure mechanisms, including hot-carriers, electromigration, and oxide breakdown. The system is normally integrated at the wafer level to predict the failure mechanisms of the production integrated circuits on the same wafer. 22 figs.

  8. On-clip high frequency reliability and failure test structures

    DOE Patents [OSTI]

    Snyder, Eric S.; Campbell, David V.

    1997-01-01

    Self-stressing test structures for realistic high frequency reliability characterizations. An on-chip high frequency oscillator, controlled by DC signals from off-chip, provides a range of high frequency pulses to test structures. The test structures provide information with regard to a variety of reliability failure mechanisms, including hot-carriers, electromigration, and oxide breakdown. The system is normally integrated at the wafer level to predict the failure mechanisms of the production integrated circuits on the same wafer.

  9. Hanford Site Environmental Restoration Program 1994 fiscal year work plan. Work breakdown structure 2.0: Revision 1

    SciTech Connect (OSTI)

    Not Available

    1993-12-22

    Site Management System (SMS) guidance requires a Fiscal Year Work Plan (FYWP) to be prepared for the Environmental Restoration (ER) Mission Area and all related programs. This revision is a complete update to cover the FY 1994 time period. This document describes the overall ER Missions Area and provides FYWP appendices for each of the following five program areas: Remedial Action (RA); Decontamination and Decommissioning (D&D); Project Management and Support (PM&S); Surveillance and Maintenance (S&M); and Disposal Facilities (DF).

  10. Design of RF Feed System for Standing-Wave Accelerator Structures

    SciTech Connect (OSTI)

    Neilson, J.; Tantawi, S.; Dolgashev, V.; /SLAC

    2012-05-25

    We are investigating a standing wave accelerator structure that uses a rf feed to each individual cell. This approach minimizes rf power flow and electromagnetic energy absorbed by an rf breakdown. The objective of this work is a robust high-gradient (above 100 MV/m) X-band accelerator structure.

  11. Design of RF Feed System for Standing-Wave Accelerator Structures

    SciTech Connect (OSTI)

    Neilson, Jeffrey; Tantawi, Sami; Dolgashev, Valery

    2010-11-04

    We are investigating a standing wave structure with an rf feed to each individual cell. This approach minimizes rf power flow and electromagnetic energy absorbed by an rf breakdown. The objective of this work is a robust high-gradient (above 100 MV/m) X-band accelerator structure.

  12. Application of laser induced breakdown spectroscopy (LIBS) instrumentation for international safeguards

    SciTech Connect (OSTI)

    Barefield Ii, James E; Clegg, Samuel M; Lopez, Leon N; Le, Loan A; Veirs, D Kirk; Browne, Mike

    2010-01-01

    Advanced methodologies and improvements to current measurements techniques are needed to strengthen the effectiveness and efficiency of international safeguards. This need was recognized and discussed at a Technical Meeting on 'The Application of Laser Spectrometry Techniques in IAEA Safeguards' held at IAEA headquarters (September 2006). One of the principal recommendations from that meeting was the need to pursue the development of novel complementary access instrumentation based on Laser Induced Breakdown Spectroscopy (UBS) for the detection of gaseous and solid signatures and indicators of nuclear fuel cycle processes and associated materials'. Pursuant to this recommendation the Department of Safeguards (SG) under the Division of Technical Support (SGTS) convened the 'Experts and Users Advisory Meeting on Laser Induced Breakdown Spectroscopy (LIBS) for Safeguards Applications' also held at IAEA headquarters (July 2008). This meeting was attended by 12 LlBS experts from the Czech Republic, the European Commission, France, the Republic of South Korea, the United States of America, Germany, the United Kingdom of Great Britain, Canada, and Northern Ireland. Following a presentation of the needs of the IAEA inspectors, the LIBS experts agreed that needs as presented could be partially or fully fulfilled using LIBS instrumentation. Inspectors needs were grouped into the following broad categories: (1) Improvements to in-field measurements/environmental sampling; (2) Monitoring status of activities in Hot Cells; (3) Verify status of activity at a declared facility via process monitoring; and (4) Need for pre-screening of environmental samples before analysis. The primary tool employed by the IAEA to detect undeclared processes and activities at special nuclear material facilities and sites is environmental sampling. One of the objectives of the Next Generation Safeguards Initiative (NGSI) Program Plan calls for the development of advanced tools and methodologies to

  13. Measurements of the volt-ampere characteristics and the breakdown voltages of direct-current helium and hydrogen discharges in microgaps

    SciTech Connect (OSTI)

    Klas, M.; Matej?ik, .; Radjenovi?, B.; Radmilovi?-Radjenovi?, M.

    2014-10-15

    The discharge phenomena for micro meter gap sizes include many interesting problems from engineering and physical perspectives. In this paper, the authors deal with the experimental and theoretical results of the breakdown voltage and current-voltage characteristics of the direct-current helium and hydrogen discharges. The measurements were performed at a constant pressure of around one atmosphere, while varying the gap size between two parallel plane tungsten electrodes between 1??m and 100??m. From the measured breakdown voltage curves, the effective yields and the ionization coefficients were derived for both gases. Present data for the ionization coefficients correlate with the data obtained for the breakdown voltage curves measured for fixed 100??m interelectrode separation. The current-voltage characteristics were plotted for the various gap sizes illustrating the role of the field emission effects in the microgaps. Based on the Fowler-Nordheim theory, the enhancement factors were determined. The gap spacing dependence of the field emission current can be explained by the introduction of two ideas, the first being a space charge effect by emitted electrons, and the second a change in the breakdown mechanism. Experimental results, presented here, demonstrate that Townsend phenomenology breaks down when field emission becomes the key mechanism affecting the breakdown and deforming the left hand side of the breakdown voltage curves.

  14. Remote Raman - laser induced breakdown spectroscopy (LIBS) geochemical investigation under Venus atmospheric conditions

    SciTech Connect (OSTI)

    Clegg, Sanuel M; Barefield, James E; Humphries, Seth D; Wiens, Roger C; Vaniman, D. T.; Sharma, S. K.; Misra, A. K.; Dyar, M. D.; Smrekar, S. E.

    2010-12-13

    The extreme Venus surface temperatures ({approx}740 K) and atmospheric pressures ({approx}93 atm) create a challenging environment for surface missions. Scientific investigations capable of Venus geochemical observations must be completed within hours of landing before the lander will be overcome by the harsh atmosphere. A combined remote Raman - LIBS (Laser Induced Breakdown Spectroscopy) instrument is capable of accomplishing the geochemical science goals without the risks associated with collecting samples and bringing them into the lander. Wiens et al. and Sharma et al. demonstrated that both analytical techniques can be integrated into a single instrument capable of planetary missions. The focus of this paper is to explore the capability to probe geologic samples with Raman - LIBS and demonstrate quantitative analysis under Venus surface conditions. Raman and LIBS are highly complementary analytical techniques capable of detecting both the mineralogical and geochemical composition of Venus surface materials. These techniques have the potential to profoundly increase our knowledge of the Venus surface composition, which is currently limited to geochemical data from Soviet Venera and VEGA landers that collectively suggest a surface composition that is primarily tholeiitic basaltic with some potentially more evolved compositions and, in some locations, K-rich trachyandesite. These landers were not equipped to probe the surface mineralogy as can be accomplished with Raman spectroscopy. Based on the observed compositional differences and recognizing the imprecise nature of the existing data, 15 samples were chosen to constitute a Venus-analog suite for this study, including five basalts, two each of andesites, dacites, and sulfates, and single samples of a foidite, trachyandesite, rhyolite, and basaltic trachyandesite under Venus conditions. LIBS data reduction involved generating a partial least squares (PLS) model with a subset of the rock powder standards to

  15. Near-critical phase explosion promoting breakdown plasma ignition during laser ablation of graphite

    SciTech Connect (OSTI)

    Ionin, A. A.; Kudryashov, S. I.; Seleznev, L. V.

    2010-07-15

    Removal rate, air shock, and ablative recoil pressure parameters were measured as a function of laser intensity I{sub peak} during nanosecond laser ablation of graphite. Surface vaporization of molten graphite at low intensities I{sub peak}<0.15 GW/cm{sup 2} was observed to transform into its near-critical phase explosion (intense homogeneous boiling) at the threshold intensity I{sub PE}approx =0.15 GW/cm{sup 2} in the form of a drastic, correlated rise of removal rate, air shock, and ablative recoil pressure magnitudes. Just above this threshold (I{sub peak}>=0.25 GW/cm{sup 2}), the explosive mass removal ended up with saturation of the removal rate, much slower increase of the air and recoil pressure magnitudes, and appearance of a visible surface plasma spark. In this regime, the measured far-field air shock pressure amplitude exhibits a sublinear dependence on laser intensity (propor toI{sub peak}{sup 4/9}), while the source plasma shock pressure demonstrates a sublinear trend (propor toI{sub peak}{sup 3/4}), both indicating the subcritical character of the plasma. Against expectations, in this regime the plasma recoil pressure increases versus I{sub peak} superlinearly (propor toI{sub peak}{sup 1.1}), rather than sublinearly (propor toI{sub peak}{sup 3/4}), with the mentioned difference related to the intensity-dependent initial spatial plasma dimensions within the laser waist on the graphite surface and to the plasma formation time during the heating laser pulse (overall, the pressure source effect). The strict coincidence of the phase explosion, providing high (kbar) hydrodynamic pressures of ablation products, and the ignition of ablative laser plasma in the carbon plume may indicate the ablative pressure-dependent character of the underlying optical breakdown at the high plume pressures, initiating the plasma formation. The experimental data evidence that the spatiotemporal extension of the plasma in the laser plume and ambient air during the heating laser

  16. Microsoft Word - Consolidated Final Complete Transcript CBS Meeting...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ... Andy is the person who runs this program day-to-day for me ... would be available to communities and again maybe they, at ... that we have to have an amendment to the Atomic Energy Act. ...

  17. Microsoft Word - Consolidated Full Transcript of DOE CBS Meeting...

    Broader source: Energy.gov (indexed) [DOE]

    ... Research and production reactors have been used over the years either for production for the weapons program or for medical isotope production, or for other purposes, and the ...

  18. Microsoft Word - Consolidated Final Transcript of CBS Tempe AZ

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    9 CONSENT-BASED SITING PUBLIC MEETING Phoenix Marriott Tempe at the Buttes 2000 W Westcourt Way Tempe, AZ 85282 June 23, 2016 FULL TRANSCRIPT Mr. Jim Hamilton. Good afternoon. And for those joining in a later time zone, good evening. Welcome to Tempe and to the sixth in a series of public meetings the Department is hosting on its Consent-Based Siting Program. Thank you all for being here today. My name is Jim Hamilton - I'm an advisor to the Department as part of their Consent-Based Siting Team

  19. UTC Power/Delphi SECA CBS Final Report

    SciTech Connect (OSTI)

    Gorman, Michael; Kerr, Rich

    2013-04-04

    The subject report summarizes the results of solid oxide fuel cell development conducted by UTC Power in conjunction with Delphi Automotive Systems under a cost-share program with from October 2008 through March of 2013. Over that period Delphi Automotive Systems developed a nearly four times larger area solid oxide fuel cell stack capable of operating on pre-reformed natural gas and simulated coal gas with durability demonstrated to 5,000 hours and projected to exceed 10,000 hours. The new stack design was scaled to 40-cell stacks with power output in excess of 6.25kW. Delphi also made significant strides in improving the manufacturability, yield and production cost of these solid oxide fuel cells over the course of the program. Concurrently, UTC Power developed a conceptual design for a 120 MW Integrated Gasification Fuel Cell (IGFC) operating on coal syngas with as high as 57% Higher Heating Value (HHV) efficiency as a measure of the feasibility of the technology. Subsequently a 400 kW on-site system preliminary design with 55% Lower Heating Value (LHV) efficiency operating on natural gas was down-selected from eighteen candidate designs. That design was used as the basis for a 25kW breadboard power plant incorporating four Delphi cell stacks that was tested on natural gas before the program was discontinued due to the sale of UTC Power in early 2013. Though the program was cut short of the endurance target of 3,000 hours, many aspects of the technology were proven including: large-area, repeatable cell manufacture, cell stack operation on simulated coal gas and natural gas and integrated power plant operation on natural gas. The potential of the technology for high efficiency stationary electric power generation is clear. Acceptable production costs, durability, and reliability in real world environments are the remaining challenges to commercialization.

  20. Microsoft Word - Final Consolitated Full Transcript Boise CBS...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ... That nationwide search, which began with more than 20 ... two-, four- and six-year terms is ill-designed to address ... and they're about to enter into construction for their site. ...

  1. Microsoft Word - Consolidated Final Transcript of CBS Tempe AZ

    Office of Environmental Management (EM)

    ... recommending a new plan for dealing with spent nuclear fuel and high-level radioactive waste. ... the importance of environmental justice on just about every one of our panels. ...

  2. Identification of vapor-phase chemical warfare agent simulants and rocket fuels using laser-induced breakdown spectroscopy

    SciTech Connect (OSTI)

    Stearns, Jaime A.; McElman, Sarah E.; Dodd, James A.

    2010-05-01

    Application of laser-induced breakdown spectroscopy (LIBS) to the identification of security threats is a growing area of research. This work presents LIBS spectra of vapor-phase chemical warfare agent simulants and typical rocket fuels. A large dataset of spectra was acquired using a variety of gas mixtures and background pressures and processed using partial least squares analysis. The five compounds studied were identified with a 99% success rate by the best method. The temporal behavior of the emission lines as a function of chamber pressure and gas mixture was also investigated, revealing some interesting trends that merit further study.

  3. Microsoft Word - SEC J_Appendix F - National Work Breakdown Str...

    National Nuclear Security Administration (NNSA)

    to input, analyze, and report budget formulation data using the NWBS structure. ... and maintenance of activity data sheets that form the foundation of the NWBS database. ...

  4. Matrix effect of sodium compounds on the determination of metal ions in aqueous solutions by underwater laser-induced breakdown spectroscopy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Goueguel, Christian; McIntyre, Dustin L.; Jain, Jinesh; Karamalidis, Athanasios K.; Carson, Cantwell

    2015-06-30

    A significant portion of the carbon sequestration research being performed in the United States involves the risk assessment of injecting large quantities of carbon dioxide into deep saline aquifers. Leakage of CO2 has the potential to affect the quality of groundwater supplies in case contaminants migrate through underlying conduits. New remote sensing and near-surface monitoring technologies are needed to ensure that injection, abandoned, and monitoring wells are structurally sound, and that CO2 remains within the geologic storage reservoir. In this paper, we propose underwater laser-induced breakdown spectroscopy (underwater LIBS) as an analytical method for monitoring naturally occurring elements that canmore » act as tracers to detect a CO2 leak from storage sites. Laboratory-scale experiments were conducted to measure Sr2+, Ca2+, K+, and Li+ in bulk solutions to ascertain the analytical performance of underwater LIBS. We compared the effect of NaCl, Na2CO3, and Na2SO4 on the analytes calibration curves to determine underwater LIBS’ ability to analyze samples of sodium compounds. In all cases, the calibration curves showed a good linearity within 2 orders of magnitude. The limit of detections (LODs) obtained for K+ (30±1 ppb) and Li+ (60±2 ppb) were in ppb range, while higher LODs were observed for Ca2+ (0.94±0.14 ppm) and Sr2+ (2.89±0.11 ppm). Evaluation of the calibration curves for the analytes in mixed solutions showed dependence of the lines’ intensity with the sodium compounds. The intensities increased respectively in the presence of dissolved NaCl and Na2SO4, whereas the intensities slightly decreased in the presence of Na2CO3. Lastly, the capabilities of underwater LIBS to detect certain elements in the ppb or in the low ppm range make it particularly appealing for in situ monitoring of a CO2 leak.« less

  5. Assessing electronic structure approaches for gas-ligand interactions in metal-organic frameworks: The CO{sub 2}-benzene complex

    SciTech Connect (OSTI)

    Witte, Jonathon; Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720 ; Neaton, Jeffrey B.; Head-Gordon, Martin; Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720

    2014-03-14

    Adsorption of gas molecules in metal-organic frameworks is governed by many factors, the most dominant of which are the interaction of the gas with open metal sites, and the interaction of the gas with the ligands. Herein, we examine the latter class of interaction in the context of CO{sub 2} binding to benzene. We begin by clarifying the geometry of the CO{sub 2}benzene complex. We then generate a benchmark binding curve using a coupled-cluster approach with single, double, and perturbative triple excitations [CCSD(T)] at the complete basis set (CBS) limit. Against this ?CCSD(T)/CBS standard, we evaluate a plethora of electronic structure approximations: Hartree-Fock, second-order Mller-Plesset perturbation theory (MP2) with the resolution-of-the-identity approximation, attenuated MP2, and a number of density functionals with and without different empirical and nonempirical van der Waals corrections. We find that finite-basis MP2 significantly overbinds the complex. On the other hand, even the simplest empirical correction to standard density functionals is sufficient to bring the binding energies to well within 1 kJ/mol of the benchmark, corresponding to an error of less than 10%; PBE-D in particular performs well. Methods that explicitly include nonlocal correlation kernels, such as VV10, vdW-DF2, and ?B97X-V, perform with similar accuracy for this system, as do ?B97X and M06-L.

  6. Dielectric-Lined High-Gradient Accelerator Structure

    SciTech Connect (OSTI)

    Jay L. Hirshfield

    2012-04-24

    Rectangular particle accelerator structures with internal planar dielectric elements have been studied, with a view towards devising structures with lower surface fields for a given accelerating field, as compared with structures without dielectrics. Success with this concept is expected to allow operation at higher accelerating gradients than otherwise on account of reduced breakdown probabilities. The project involves studies of RF breakdown on amorphous dielectrics in test cavities that could enable high-gradient structures to be built for a future multi-TeV collider. The aim is to determine what the limits are for RF fields at the surfaces of selected dielectrics, and the resulting acceleration gradient that could be achieved in a working structure. The dielectric of principal interest in this study is artificial CVD diamond, on account of its advertised high breakdown field ({approx}2 GV/m for dc), low loss tangent, and high thermal conductivity. Experimental studies at mm-wavelengths on materials and structures for achieving high acceleration gradient were based on the availability of the 34.3 GHz third-harmonic magnicon amplifier developed by Omega-P, and installed at the Yale University Beam Physics Laboratory. Peak power from the magnicon was measured to be about 20 MW in 0.5 {micro}s pulses, with a gain of 54 dB. Experiments for studying RF high-field effects on CVD diamond samples failed to show any evidence after more than 10{sup 5} RF pulses of RF breakdown up to a tangential surface field strength of 153 MV/m; studies at higher fields were not possible due to a degradation in magnicon performance. A rebuild of the tube is underway at this writing. Computed performance for a dielectric-loaded rectangular accelerator structure (DLA) shows highly competitive properties, as compared with an existing all-metal structure. For example, comparisons were made of a DLA structure having two planar CVD diamond elements with a all-metal CERN structure HDS

  7. Breakdown of ionic character of molecular alkali bromides in inner-valence photoionization

    SciTech Connect (OSTI)

    Karpenko, A. Iablonskyi, D.; Kettunen, J. A.; Cao, W.; Huttula, M.; Aksela, H.; Urpelainen, S.

    2014-05-28

    The inner-valence region of alkali bromide XBr (X=Li, Na, K, Rb) vapours has been studied experimentally by means of synchrotron radiation excited photoelectron spectroscopy. Experimental spectra were analyzed by comparing them with available theoretical results and previous experiments. Ionic character of alkali bromides is seen to change in the inner-valence region with increasing atomic number of the alkali atom. A mechanism involving mixing between Br 4s and Rb 4p orbitals has been suggested to account for the fine structure observed in inner-valence ionization region of RbBr.

  8. Effects of Combustion-Induced Vortex Breakdown on Flashback Limits of Syngas-Fueled Gas Turbine Combustors

    SciTech Connect (OSTI)

    Ahsan Choudhuri

    2011-03-31

    Turbine combustors of advanced power systems have goals to achieve very low pollutants emissions, fuel variability, and fuel flexibility. Future generation gas turbine combustors should tolerate fuel compositions ranging from natural gas to a broad range of syngas without sacrificing operational advantages and low emission characteristics. Additionally, current designs of advanced turbine combustors use various degrees of swirl and lean premixing for stabilizing flames and controlling high temperature NOx formation zones. However, issues of fuel variability and NOx control through premixing also bring a number of concerns, especially combustor flashback and flame blowout. Flashback is a combustion condition at which the flame propagates upstream against the gas stream into the burner tube. Flashback is a critical issue for premixed combustor designs, because it not only causes serious hardware damages but also increases pollutant emissions. In swirl stabilized lean premixed turbine combustors onset of flashback may occur due to (i) boundary layer flame propagation (critical velocity gradient), (ii) turbulent flame propagation in core flow, (iii) combustion instabilities, and (iv) upstream flame propagation induced by combustion induced vortex breakdown (CIVB). Flashback due to first two foregoing mechanisms is a topic of classical interest and has been studied extensively. Generally, analytical theories and experimental determinations of laminar and turbulent burning velocities model these mechanisms with sufficient precision for design usages. However, the swirling flow complicates the flashback processes in premixed combustions and the first two mechanisms inadequately describe the flashback propensity of most practical combustor designs. The presence of hydrogen in syngas significantly increases the potential for flashback. Due to high laminar burning velocity and low lean flammability limit, hydrogen tends to shift the combustor operating conditions towards

  9. Numerical simulation of torus breakdown to chaos in an atmospheric-pressure dielectric barrier discharge

    SciTech Connect (OSTI)

    Zhang, J.; Wang, Y. H.; Wang, D. Z. [Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)] [Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

    2013-08-15

    Understanding the routes to chaos occurring in atmospheric-pressure dielectric barrier discharge systems by changing controlling parameters is very important to predict and control the dynamical behaviors. In this paper, a route of a quasiperiodic torus to chaos via the strange nonchaotic attractor is observed in an atmospheric-pressure dielectric barrier discharge driven by triangle-wave voltage. By increasing the driving frequency, the discharge system first bifurcates to a quasiperiodic torus from a stable single periodic state, and then torus and phase-locking periodic state appear and disappear alternately. In the meantime, the torus becomes increasingly wrinkling and stretching, and gradually approaches a fractal structure with the nonpositive largest Lyapunov exponent, i.e., a strange nonchaotic attractor. After that, the discharge system enters into chaotic state. If the driving frequency is further increased, another well known route of period-doubling bifurcation to chaos is also observed.

  10. Matrix effect of sodium compounds on the determination of metal ions in aqueous solutions by underwater laser-induced breakdown spectroscopy

    SciTech Connect (OSTI)

    Goueguel, Christian; McIntyre, Dustin L.; Jain, Jinesh; Karamalidis, Athanasios K.; Carson, Cantwell

    2015-06-30

    A significant portion of the carbon sequestration research being performed in the United States involves the risk assessment of injecting large quantities of carbon dioxide into deep saline aquifers. Leakage of CO2 has the potential to affect the quality of groundwater supplies in case contaminants migrate through underlying conduits. New remote sensing and near-surface monitoring technologies are needed to ensure that injection, abandoned, and monitoring wells are structurally sound, and that CO2 remains within the geologic storage reservoir. In this paper, we propose underwater laser-induced breakdown spectroscopy (underwater LIBS) as an analytical method for monitoring naturally occurring elements that can act as tracers to detect a CO2 leak from storage sites. Laboratory-scale experiments were conducted to measure Sr2+, Ca2+, K+, and Li+ in bulk solutions to ascertain the analytical performance of underwater LIBS. We compared the effect of NaCl, Na2CO3, and Na2SO4 on the analytes calibration curves to determine underwater LIBS’ ability to analyze samples of sodium compounds. In all cases, the calibration curves showed a good linearity within 2 orders of magnitude. The limit of detections (LODs) obtained for K+ (30±1 ppb) and Li+ (60±2 ppb) were in ppb range, while higher LODs were observed for Ca2+ (0.94±0.14 ppm) and Sr2+ (2.89±0.11 ppm). Evaluation of the calibration curves for the analytes in mixed solutions showed dependence of the lines’ intensity with the sodium compounds. The intensities increased respectively in the presence of dissolved NaCl and Na2SO4, whereas the intensities slightly decreased in the presence of Na2CO3. Lastly, the capabilities of underwater LIBS to detect certain elements in the ppb or in the low ppm range make it

  11. Time-Resolved Imaging of Material Response Following Laser-Induced Breakdown in the Bulk and Surface of Fused Silica

    SciTech Connect (OSTI)

    Raman, R N; Negres, R A; DeMange, P; Demos, S G

    2010-02-04

    Optical components within high energy laser systems are susceptible to laser-induced material modification when the breakdown threshold is exceeded or damage is initiated by pre-existing impurities or defects. These modifications are the result of exposure to extreme conditions involving the generation of high temperatures and pressures and occur on a volumetric scale of the order of a few cubic microns. The response of the material following localized energy deposition, including the timeline of events and the individual processes involved during this timeline, is still largely unknown. In this work, we investigate the events taking place during the entire timeline in both bulk and surface damage in fused silica using a set of time-resolved microscopy systems. These microscope systems offer up to 1 micron spatial resolution when imaging static or dynamic effects, allowing for imaging of the entire process with adequate temporal and spatial resolution. These systems incorporate various pump-probe geometries designed to optimize the sensitivity for detecting individual aspects of the process such as the propagation of shock waves, near-surface material motion, the speed of ejecta, and material transformations. The experimental results indicate that the material response can be separated into distinct phases, some terminating within a few tens of nanoseconds but some extending up to about 100 microseconds. Overall the results demonstrate that the final characteristics of the modified region depend on the material response to the energy deposition and not on the laser parameters.

  12. Characteristics of the dynamics of breakdown filaments in Al{sub 2}O{sub 3}/InGaAs stacks

    SciTech Connect (OSTI)

    Palumbo, F.; Shekhter, P.; Eizenberg, M.; Cohen Weinfeld, K.

    2015-09-21

    In this paper, the Al{sub 2}O{sub 3}/InGaAs interface was studied by X-ray photoelectron spectroscopy (XPS) after a breakdown (BD) event at positive bias applied to the gate contact. The dynamics of the BD event were studied by comparable XPS measurements with different current compliance levels during the BD event. The overall results show that indium atoms from the substrate move towards the oxide by an electro-migration process and oxidize upon arrival following a power law dependence on the current compliance of the BD event. Such a result reveals the physical feature of the breakdown characteristics of III-V based metal-oxide-semiconductor devices.

  13. Physics-Based Compact Model for CIGS and CdTe Solar Cells: From Voltage-Dependent Carrier Collection to Light-Enhanced Reverse Breakdown: Preprint

    SciTech Connect (OSTI)

    Sun, Xingshu; Alam, Muhammad Ashraful; Raguse, John; Garris, Rebekah; Deline, Chris; Silverman, Timothy

    2015-10-15

    In this paper, we develop a physics-based compact model for copper indium gallium diselenide (CIGS) and cadmium telluride (CdTe) heterojunction solar cells that attributes the failure of superposition to voltage-dependent carrier collection in the absorber layer, and interprets light-enhanced reverse breakdown as a consequence of tunneling-assisted Poole-Frenkel conduction. The temperature dependence of the model is validated against both simulation and experimental data for the entire range of bias conditions. The model can be used to characterize device parameters, optimize new designs, and most importantly, predict performance and reliability of solar panels including the effects of self-heating and reverse breakdown due to partial-shading degradation.

  14. Final Report: Investigation of Catalytic Pathways for Lignin Breakdown into Monomers and Fuels

    SciTech Connect (OSTI)

    Gluckstein, Jeffrey A; Hu, Michael Z.; Kidder, Michelle; McFarlane, Joanna; Narula, Chaitanya Kumar; Sturgeon, Matthew R

    2010-12-01

    Lignin is a biopolymer that comprises up to 35% of woody biomass by dry weight. It is currently underutilized compared to cellulose and hemicellulose, the other two primary components of woody biomass. Lignin has an irregular structure of methoxylated aromatic groups linked by a suite of ether and alkyl bonds which makes it difficult to degrade selectively. However, the aromatic components of lignin also make it promising as a base material for the production of aromatic fuel additives and cyclic chemical feed stocks such as styrene, benzene, and cyclohexanol. Our laboratory research focused on three methods to selectively cleave and deoxygenate purified lignin under mild conditions: acidolysis, hydrogenation and electrocatalysis. (1) Acidolysis was undertaken in CH2Cl2 at room temperature. (2) Hydrogenation was carried out by dissolving lignin and a rhodium catalyst in 1:1 water:methoxyethanol under a 1 atm H2 environment. (3) Electrocatalysis of lignin involved reacting electrically generated hydrogen atoms at a catalytic palladium cathode with lignin dissolved in a solution of aqueous methanol. In all of the experiments, the lignin degradation products were identified and quantified by gas chromatography mass spectroscopy and flame ionization detection. Yields were low, but this may have reflected the difficulty in recovering the various fractions after conversion. The homogeneous hydrogenation of lignin showed fragmentation into monomers, while the electrocatalytic hydrogenation showed production of polyaromatic hydrocarbons and substituted benzenes. In addition to the experiments, promising pathways for the conversion of lignin were assessed. Three conversion methods were compared based on their material and energy inputs and proposed improvements using better catalyst and process technology. A variety of areas were noted as needing further experimental and theoretical effort to increase the feasibility of lignin conversion to fuels.

  15. Status of High Power Tests of Normal Conducting Single-Cell Structures

    SciTech Connect (OSTI)

    Dolgashev, V.A.; Tantawi, S.G.; Higashi, Y.; Higo, T.; /KEK, Tsukuba

    2011-11-04

    We report the results of ongoing high power tests of single-cell standing wave structures. These tests are part of an experimental and theoretical study of rf breakdown in normal conducting structures at 11.4 GHz. The goal of this study is to determine the maximum gradient possibilities for normal-conducting rf powered particle beam accelerators. The test setup consists of reusable mode launchers and short test structures powered by SLACs XL-4 klystron. The mode launchers and structures were manufactured at SLAC and KEK and tested at the SLAC klystron test laboratory.

  16. A Comparison of the Effect of Temperature on the Passivity Breakdown and Repassivation Potentials of Wrought and Welded Alloy 22 in 5 M CAC12

    SciTech Connect (OSTI)

    Ilevbare, G

    2003-02-14

    The study of the electrochemical behavior of wrought and welded Alloy 22 was carried out in 5 M CaC12 at various temperatures. Comparisons were made between the electrochemical behaviors of the wrought and welded forms of Alloy 22 Multiple Crevice Assembly (MCA) specimens. The susceptibility to corrosion was found to increase with increase in temperature in both the wrought and the welded forms of the alloy: Nevertheless, the measure critical breakdown potential E{sub crit} was found to be Similar for the wrought and welded specimens.

  17. Detection of rare earth elements in Powder River Basin sub-bituminous coal ash using laser-induced breakdown spectroscopy (LIBS)

    SciTech Connect (OSTI)

    Tran, Phuoc

    2015-10-01

    We reported our preliminary results on the use of laser-induced breakdown spectroscopy to analyze the rare earth elements contained in ash samples from Powder River Basin sub-bituminous coal (PRB-coal). We have identified many elements in the lanthanide series (cerium, europium, holmium, lanthanum, lutetium, praseodymium, promethium, samarium, terbium, ytterbium) and some elements in the actinide series (actinium, thorium, uranium, plutonium, berkelium, californium) in the ash samples. In addition, various metals were also seen to present in the ash samples

  18. Study of the dielectric breakdown properties of hot SF{sub 6}CF{sub 4} mixtures at 0.011.6 MPa

    SciTech Connect (OSTI)

    Li, Xingwen; Zhao, Hu; Jia, Shenli; Murphy, Anthony B.

    2013-08-07

    The dielectric breakdown properties of SF{sub 6}CF{sub 4} mixtures were investigated at different ratios of SF{sub 6}, 0.011.6 MPa, and gas temperatures up to 3000 K. Initially, the equilibrium compositions of SF{sub 6}CF{sub 4} mixtures were calculated by minimizing the Gibbs free energy under the assumptions of local thermodynamic and chemical equilibrium. Then the electron energy distribution function was obtained based on those data by solving the Boltzmann equation under the zero-dimensional two-term spherical harmonic approximation. Finally, the critical reduced electric field strength (E/N){sub cr} of SF{sub 6}CF{sub 4} mixtures, which is defined as the value for which total ionization reaction is equal to total attachment reaction, were determined and analyzed. The results confirm the superior breakdown properties of pure SF{sub 6} at relatively low gas temperatures. However, for higher gas temperatures (i.e., T > 2200 K at 0.4 MPa), the (E/N){sub cr} in SF{sub 6}CF{sub 4} mixtures are obviously higher than that in pure SF{sub 6} and the values of (E/N){sub cr} increase with the reduction of the ratio of SF{sub 6}.

  19. The Structure of the Proton

    DOE R&D Accomplishments [OSTI]

    Chambers, E. E.; Hofstadter, R.

    1956-04-01

    The structure and size of the proton have been studied by means of the methods of high-energy electron scattering. The elastic scattering of electrons from protons in polyethylene has been investigated at the following energies in the laboratory system: 200, 300, 400, 500, 550 Mev. The range of laboratory angles examined has been 30 degrees to 135 degrees. At the largest angles and the highest energy, the cross section for scattering shows a deviation below that expected from a point proton by a factor of about nine. The magnitude and variation with angle of the deviations determine a structure factor for the proton, and thereby determine the size and shape of the charge and magnetic-moment distributions within the proton. An interpretation, consistent at all energies and angles and agreeing with earlier results from this laboratory, fixes the rms radius at 0.77 {plus or minus} 0.10 x 10{sup -13} cm for each of the charge and moment distributions. The shape of the density function is not far from a Gaussian with rms radius 0.70 x 10{sup -13} cm or an exponential with rms radius 0.80 x 10 {sup -13} cm. An equivalent interpretation of the experiments would ascribe the apparent size to a breakdown of the Coulomb law and the conventional theory of electromagnetism.

  20. Relationship between the structure and electrical characteristics of diamond-like carbon films

    SciTech Connect (OSTI)

    Takabayashi, Susumu Otsuji, Taiichi; Yang, Meng; Ogawa, Shuichi; Hayashi, Hiroyuki; Jeko, Radek; Takakuwa, Yuji

    2014-09-07

    To elucidate the relationship between the structure and the electrical characteristics of diamond-like carbon (DLC) films, DLC films were synthesized in a well-controlled glow discharge with the aid of photoelectrons in an argon/methane atmosphere. The dielectric constant and breakdown strength of the films exhibited opposite behaviors, depending on the total pressure during the synthesis. The product of these two values decreased monotonically as the pressure increased. The Raman spectra were analyzed with a Voigt-type formula. Based on the results, the authors propose the sp{sup 2} cluster model for the DLC structure. This model consists of conductive clusters of sp{sup 2} carbons surrounded by a dielectric matrix sea of sp{sup 2} carbon, sp{sup 3} carbon, and hydrogen, and indicates that the dielectric constant of the whole DLC film is determined by the balance between the dielectric constant of the matrix and the total size of the clusters, while the breakdown strength is determined by the reciprocal of the cluster size. The model suggests that a high-? DLC film can be synthesized at a middle pressure and consists of well-grown sp{sup 2} clusters and a dense matrix. A low-? DLC film can be synthesized both at low and high pressures. The sp{sup 2} cluster model explains that a low-? DLC film synthesized at low pressure consists of a dense matrix and a low density of sp{sup 2} clusters, and exhibits a high breakdown strength. On the other hand, a low-? film synthesized at high pressure consists of a coarse matrix and a high density of clusters and exhibits a low breakdown strength.

  1. Imaging of the spatial distribution of atoms in an optical-breakdown plasma with one-dimensional coherent hyper-Raman scattering

    SciTech Connect (OSTI)

    Akimov, Denis A; Zheltikov, Aleksei M; Koroteev, Nikolai I; Naumov, A N; Fedotov, Andrei B; Miles, R B; Sidorov-Biryukov, D A

    1998-12-31

    A technique based on coherent four-wave mixing with a hyper-Raman resonance in wide beams was developed for line-by-line reconstruction of the spatial distribution of excited atoms in a laser-produced plasma. This method was used to study the spatial distribution of excited lead atoms in an optical-breakdown plasma formed on a metal target. A comparison was made of the technique of constructing plasma images line-by-line with a four-photon technique of point-by-point measurements. Estimates were obtained of the spatial resolution of the proposed technique. Potential applications of this approach in plasma diagnostics were analysed. (interaction of laser radiation with matter. laser plasma)

  2. Elemental content of enamel and dentin after bleaching of teeth (a comparative study between laser-induced breakdown spectroscopy and x-ray photoelectron spectroscopy)

    SciTech Connect (OSTI)

    Imam, H.; Ahmed, Doaa; Eldakrouri, Ashraf; Department of Optometry and Vision Science, College of Applied Medical Science, King Saud University, Riyadh

    2013-06-21

    The elemental content of the superficial and inner enamel as well as that of dentin was analyzed using laser-induced breakdown spectroscopy (LIBS) and x-ray photoelectron spectroscopy (XPS) of bleached and unbleached tooth specimens. It is thus clear from the spectral analysis using both the LIBS and XPS technique that elemental changes (though insignificant within the scopes of this study) of variable intensities do occur on the surface of the enamel and extend deeper to reach dentin. The results of the LIBS revealed a slight reduction in the calcium levels in the bleached compared to the control specimens in all the different bleaching groups and in both enamel and dentin. The good correlation found between the LIBS and XPS results demonstrates the possibility of LIBS technique for detection of minor loss in calcium and phosphorus in enamel and dentin.

  3. Dynamics of ionization processes in high-pressure nitrogen, air, and SF{sub 6} during a subnanosecond breakdown initiated by runaway electrons

    SciTech Connect (OSTI)

    Tarasenko, V. F. Beloplotov, D. V.; Lomaev, M. I.

    2015-10-15

    The dynamics of ionization processes in high-pressure nitrogen, air, and SF{sub 6} during breakdown of a gap with a nonuniform distribution of the electric field by nanosecond high-voltage pulses was studied experimentally. Measurements of the amplitude and temporal characteristics of a diffuse discharge and its radiation with a subnanosecond time resolution have shown that, at any polarity of the electrode with a small curvature radius, breakdown of the gap occurs via two ionization waves, the first of which is initiated by runaway electrons. For a voltage pulse with an ∼500-ps front, UV radiation from different zones of a diffuse discharge is measured with a subnanosecond time resolution. It is shown that the propagation velocity of the first ionization wave increases after its front has passed one-half of the gap, as well as when the pressure in the discharge chamber is reduced and/or when SF{sub 6} is replaced with air or nitrogen. It is found that, at nitrogen pressures of 0.4 and 0.7 MPa and the positive polarity of the high-voltage electrode with a small curvature radius, the ionization wave forms with a larger (∼30 ps) time delay with respect to applying the voltage pulse to the gap than at the negative polarity. The velocity of the second ionization wave propagating from the plane electrode is measured. In a discharge in nitrogen at a pressure of 0.7 MPa, this velocity is found to be ∼10 cm/ns. It is shown that, as the nitrogen pressure increases to 0.7 MPa, the propagation velocity of the front of the first ionization wave at the positive polarity of the electrode with a small curvature radius becomes lower than that at the negative polarity.

  4. Summary report of working group 3: High gradient and laser-structure based acceleration

    SciTech Connect (OSTI)

    Solyak, N.; Cowan, B.M.; /Tech-X, Boulder

    2010-01-01

    The charge for the working group on high gradient and laser-structure based acceleration was to assess the current challenges involved in developing an advanced accelerator based on electromagnetic structures, and survey state-of-the-art methods to address those challenges. The topics of more than 50 presentations in the working group covered a very broad range of issues, from ideas, theoretical models and simulations, to design and manufacturing of accelerating structures and, finally, experimental results on obtaining extremely high accelerating gradients in structures from conventional microwave frequency range up to THz and laser frequencies. Workshop discussion topics included advances in the understanding of the physics of breakdown and other phenomena, limiting high gradient performance of accelerating structures. New results presented in this workshop demonstrated significant progress in the fields of conventional vacuum structure-based acceleration, dielectric wakefield acceleration, and laser-structure acceleration.

  5. Dielectric breakdown properties of hot SF{sub 6}-CO{sub 2} mixtures at temperatures of 3003500?K and pressures of 0.011.0?MPa

    SciTech Connect (OSTI)

    Zhong, Linlin; Yang, Aijun; Wang, Xiaohua Liu, Dingxin; Wu, Yi; Rong, Mingzhe

    2014-05-15

    Recently, much attention has been paid to SF{sub 6}-CO{sub 2} mixtures as one of substitutes for pure SF{sub 6} gas. In this paper, the dielectric breakdown properties of hot SF{sub 6}-CO{sub 2} mixtures are investigated at temperatures of 3003500?K and pressures of 0.011.0?MPa. Under the assumptions of local thermodynamic equilibrium and local chemical equilibrium, the equilibrium compositions of hot SF{sub 6}-CO{sub 2} mixtures with different CO{sub 2} proportions are obtained based on Gibbs free energy minimization. The cross sections for interactions between electrons and neutral species are presented. Some unknown ionization cross sections are determined theoretically using DeutschMrk (DM) formalism based on quantum chemistry. Two-term Boltzmann equation is adopted to calculate the electron energy distribution function, reduced ionization coefficient, reduced attachment coefficient, and reduced effective ionization coefficient. Then the reduced critical electric field strength of mixtures, corresponding to dielectric breakdown performances, is determined when the generation and loss of electrons are balanced. Finally, the influences of temperature, pressure, and CO{sub 2} proportion on the reduced critical electric field strength are studied. It is found that a large percentage of CO{sub 2} can obviously reduce concentrations of high-energy electrons. At temperatures above 1750?K, an addition of CO{sub 2} to SF{sub 6} gas can enhance dielectric breakdown performances. However, at low temperatures, too much CO{sub 2} added into mixtures can reduce dielectric breakdown abilities. In addition, increasing gas pressure can improve dielectric breakdown performances. But the influence will be no more significant if pressure is over 0.8?MPa.

  6. Trench process and structure for backside contact solar cells with polysilicon doped regions

    DOE Patents [OSTI]

    De Ceuster, Denis; Cousins, Peter John; Smith, David D

    2013-05-28

    A solar cell includes polysilicon P-type and N-type doped regions on a backside of a substrate, such as a silicon wafer. An interrupted trench structure separates the P-type doped region from the N-type doped region in some locations but allows the P-type doped region and the N-type doped region to touch in other locations. Each of the P-type and N-type doped regions may be formed over a thin dielectric layer. Among other advantages, the resulting solar cell structure allows for increased efficiency while having a relatively low reverse breakdown voltage.

  7. Trench process and structure for backside contact solar cells with polysilicon doped regions

    DOE Patents [OSTI]

    De Ceuster, Denis; Cousins, Peter John; Smith, David D

    2014-03-18

    A solar cell includes polysilicon P-type and N-type doped regions on a backside of a substrate, such as a silicon wafer. An interrupted trench structure separates the P-type doped region from the N-type doped region in some locations but allows the P-type doped region and the N-type doped region to touch in other locations. Each of the P-type and N-type doped regions may be formed over a thin dielectric layer. Among other advantages, the resulting solar cell structure allows for increased efficiency while having a relatively low reverse breakdown voltage.

  8. Trench process and structure for backside contact solar cells with polysilicon doped regions

    DOE Patents [OSTI]

    De Ceuster, Denis; Cousins, Peter John; Smith, David D.

    2010-12-14

    A solar cell includes polysilicon P-type and N-type doped regions on a backside of a substrate, such as a silicon wafer. An interrupted trench structure separates the P-type doped region from the N-type doped region in some locations but allows the P-type doped region and the N-type doped region to touch in other locations. Each of the P-type and N-type doped regions may be formed over a thin dielectric layer. Among other advantages, the resulting solar cell structure allows for increased efficiency while having a relatively low reverse breakdown voltage.

  9. STRUCtural Simulator

    Energy Science and Technology Software Center (OSTI)

    2004-07-01

    STRUC-ANL is a derivative of the FLUSTR-ANL finite element code. It contains only the structural capabilities of the original fluid-structural FLUSTR code.

  10. Structural Materials

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Structural Materials Development enables advanced technologies through the discovery, development, and demonstration of cost-effective advanced structural materials for use in ...

  11. U.S. Photovoltaic Prices and Cost Breakdowns. Q1 2015 Benchmarks for Residential, Commercial, and Utility-Scale Systems

    SciTech Connect (OSTI)

    Chung, Donald; Davidson, Carolyn; Fu, Ran; Ardani, Kristen; Margolis, Robert

    2015-09-01

    The price of photovoltaic (PV) systems in the United States (i.e., the cost to the system owner) has continued to decline across all major market sectors. This report provides a Q1 2015 update regarding the prices of residential, commercial, and utility scale PV systems, based on an objective methodology that closely approximates the book value of a PV system. Several cases are benchmarked to represent common variations in business models, labor rates, and system architecture choice. We estimate a weighted-average cash purchase price of $3.09/W for residential scale rooftop systems, $2.15/W for commercial scale rooftop systems, $1.77/W for utility scale systems with fixed mounting structures, and $1.91/W for utility scale systems using single-axis trackers. All systems are modeled assuming standard-efficiency, polycrystalline-silicon PV modules, and further assume installation within the United States.

  12. Functional and structural diversity in GH62 α-L-arabinofuranosidases from the thermophilic fungus Scytalidium thermophilum

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kaur, Amrit Pal; Nocek, Boguslaw P.; Xu, Xiaohui; Lowden, Michael J.; Leyva, Juan Francisco; Stogios, Peter J.; Cui, Hong; Leo, Rosa Di; Powlowski, Justin; Tsang, Adrian; et al

    2015-05-01

    The genome of the thermophilic fungus Scytalidium thermophilum (strain CBS 625.91) harbours a wide range of genes involved in carbohydrate degradation, including three genes, abf62A, abf62B and abf62C, predicted to encode glycoside hydrolase family 62 (GH62) enzymes. Transcriptome analysis showed that only abf62A and abf62C are actively expressed during growth on diverse substrates including straws from barley, alfalfa, triticale and canola. The abf62A and abf62C genes were expressed in Escherichia coli and the resulting recombinant proteins were characterized. Calcium-free crystal structures of Abf62C in apo and xylotriose bound forms were determined to 1.23 and 1.48 Å resolution respectively. Site-directed mutagenesismore » confirmed Asp55, Asp171 and Glu230 as catalytic triad residues, and revealed the critical role of non-catalytic residues Asp194, Trp229 and Tyr338 in positioning the scissile α-L-arabinofuranoside bond at the catalytic site. Further, the +2R substrate-binding site residues Tyr168 and Asn339, as well as the +2NR residue Tyr226, are involved in accommodating long-chain xylan polymers. Overall, our structural and functional analysis highlights characteristic differences between Abf62A and Abf62C, which represent divergent subgroups in the GH62 family.« less

  13. Performance testing of a Laser-Induced Breakdown Spectroscopy (LIBS) based continuous metal emissions monitor at a pyrolytic waste treatment facility

    SciTech Connect (OSTI)

    Hahn, D.W.; Hencken, K.R.; Johnsen, H.A.

    1997-07-01

    A program was initiated at Sandia National Laboratories to develop and demonstrate an advanced continuous emissions monitor that will provide realtime measurement of metal emissions in the wastestreams of thermal treatment facilities. This effort led to the development of a prototype metals monitor based on an optical technique referred to as laser-induced breakdown spectroscopy (LIBS). The measurements are performed in situ, and are both noninvasive and real-time. The automated software incorporates a new conditional analysis algorithm that utilizes single particle detection. The metal emissions monitor was tested during March 1997 at a pilot scale pyrolytic waste processing facility in Santa Fe Springs, California. This report describes the field test, including the monitor installation, test cycle, and overall instrument performance. The Clean Air Act metals chromium and manganese were recorded at concentrations from approximately 2 to 5 parts per billion. Iron was recorded at concentrations from 40 to 140 parts per billion. The overall accuracy was in very good agreement with contracted EPA Reference Method 29 results. Overall, the LIBS-based metals monitor performed exceptionally well on a waste treatment facility with very low metal emissions levels. 19 refs., 12 tabs., 3 figs.

  14. Homogeneity testing and quantitative analysis of manganese (Mn) in vitrified Mn-doped glasses by laser-induced breakdown spectroscopy (LIBS)

    SciTech Connect (OSTI)

    Unnikrishnan, V. K.; Nayak, Rajesh; Kartha, V. B.; Santhosh, C. E-mail: unnikrishnan.vk@manipal.edu; Sonavane, M. S.; Yeotikar, R. G.; Shah, M. L.; Gupta, G. P.; Suri, B. M.

    2014-09-15

    Laser-induced breakdown spectroscopy (LIBS), an atomic emission spectroscopy method, has rapidly grown as one of the best elemental analysis techniques over the past two decades. Homogeneity testing and quantitative analysis of manganese (Mn) in manganese-doped glasses have been carried out using an optimized LIBS system employing a nanosecond ultraviolet Nd:YAG laser as the source of excitation. The glass samples have been prepared using conventional vitrification methods. The laser pulse irradiance on the surface of the glass samples placed in air at atmospheric pressure was about 1.710{sup 9} W/cm{sup 2}. The spatially integrated plasma emission was collected and imaged on to the spectrograph slit using an optical-fiber-based collection system. Homogeneity was checked by recording LIBS spectra from different sites on the sample surface and analyzing the elemental emission intensities for concentration determination. Validation of the observed LIBS results was done by comparison with scanning electron microscope- energy dispersive X-ray spectroscopy (SEM-EDX) surface elemental mapping. The analytical performance of the LIBS system has been evaluated through the correlation of the LIBS determined concentrations of Mn with its certified values. The results are found to be in very good agreement with the certified concentrations.

  15. The breakdown of de Gennes Scaling in TbxEr1-xNi2B2C and its mean field theory explanation

    SciTech Connect (OSTI)

    Gao, Chunwang

    2005-05-01

    The Neel temperatures, T{sub N}, of Tb{sub x}Er{sub 1-x}Ni{sub 2}B{sub 2}C samples have been determined from the temperature dependence of magnetization measurements. A breakdown of the de Gennes scaling of T{sub N} with a clear turning point around x = 0.45 has been observed. The T{sub N} values of Tb{sub x}Er{sub 1-x}Ni{sub 2}B{sub 2}C do not change much within the range of O < x < 0.45 and then, for larger x they increase almost linearly with concentration until T{sub N} = 14.9K is reached for x = 1, TbNi{sub 2}B{sub 2}C. The clear change in the x-dependence of T{sub N} around x = 0.45 can be linked to a change in the local moment ordering direction from transverse to longitudinal, a change which is consistent with recent resonant X-ray scattering data. These features in T{sub N}(x) can be explained using a mean field model.

  16. Space charge inhibition effect of nano-Fe{sub 3}O{sub 4} on improvement of impulse breakdown voltage of transformer oil based on improved Kerr optic measurements

    SciTech Connect (OSTI)

    Yang, Qing Yu, Fei; Sima, Wenxia; Zahn, Markus

    2015-09-15

    Transformer oil-based nanofluids (NFs) with 0.03 g/L Fe{sub 3}O{sub 4} nanoparticle content exhibit 11.2% higher positive impulse breakdown voltage levels than pure transformer oils. To study the effects of the Fe{sub 3}O{sub 4} nanoparticles on the space charge in transformer oil and to explain why the nano-modified transformer oil exhibits improved impulse breakdown voltage characteristics, the traditional Kerr electro-optic field mapping technique is improved by increasing the length of the parallel-plate electrodes and by using a photodetector array as a high light sensitivity device. The space charge distributions of pure transformer oil and of NFs containing Fe{sub 3}O{sub 4} nanoparticles can be measured using the improved Kerr electro-optic field mapping technique. Test results indicate a significant reduction in space charge density in the transformer oil-based NFs with the Fe{sub 3}O{sub 4} nanoparticles. The fast electrons are captured by the nanoparticles and are converted into slow-charged particles in the NFs, which then reduce the space charge density and result in a more uniform electric field distribution. Streamer propagation in the NFs is also obstructed, and the breakdown strengths of the NFs under impulse voltage conditions are also improved.

  17. Microsoft Word - Consolidated Final Complete Transcript CBS Meeting Boston_Final v1

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Hyatt Regency Boston One Avenue De Lafayette Boston, MA 02111 June 2, 2016 FULL TRANSCRIPT Mr. Jim Hamilton. Good afternoon. Welcome to Boston, and to the fifth in a series of public meetings the Department is hosting on its Consent-Based Siting Program. Thank you all for being here today. I'm especially happy to welcome you for two reasons. One is, I live in Boston, so, welcome to my hometown. But more importantly, we've got an excellent panel here in front of you here today, and I'm looking

  18. Microsoft Word - Consolidated Full Transcript of DOE CBS Meeting Minneapolis 21 JUL 16_Final

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    CONSENT-BASED SITING PUBLIC MEETING Hilton Minneapolis 1001 Marquette Avenue Minneapolis, MN 55403 July 21, 2016 FULL TRANSCRIPT Mr. Jim Hamilton. Good afternoon. And for those joining us in later time zones via webinar, good evening. Welcome to Minneapolis and to the eighth in a series of public meetings the Department is hosting on its Consent-Based Siting Program. Thank you all very much for being here today. My name is Jim Hamilton; I'm an advisor to the Department as part of their

  19. Microsoft Word - Consolidated Verbatim Transcript CBS Meeting Sacramento California Transcripts_Final

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Holiday Inn Capitol Plaza Sacramento 300 J Street Sacramento, CA 95814 April 26, 2016 VERBATIM TRANSCRIPT Mr. Jim Hamilton. Good afternoon. And for those in later time zones via webinar, good evening. Welcome, and thank you for being here today. My name is Jim Hamilton. I'm an advisor to the Department of Energy's Consent-Based Siting Team and my role here today is to help us all to have a good, open, productive conversation. To start off we have a few housekeeping issues I want to talk about

  20. Microsoft Word - Final Consolitated Full Transcript Boise CBS Meeting_Final

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    P a g e CONSENT-BASED SITING PUBLIC MEETING Boise Centre 850 West Front Street Boise, ID 83702 July 14, 2016 FULL TRANSCRIPT Mr. Jim Hamilton. Good afternoon, and for those of you joining us in a later time zone, through the webinar, good evening. Welcome to Boise, and to the seventh in a series of public meetings the Department is hosting on its Consent-Based Siting Program. Thank you all for being here today. My name is Jim Hamilton; I'm an advisor to the Department as part of its

  1. Design and Analysis of Muon Beam Stop Support Structures

    SciTech Connect (OSTI)

    Okafor, Udenna

    2015-01-01

    The primary objective of this thesis is to design and analyze support structures to be used in the installation, test and final positioning of the MBS throughout the life of the Mu2e experiment. There several requirements for the MBS imposed by both the scope of the experiment and, other components within the DS bore. The functions of the MBS are: 1. To limit the induced rates in the Tracker, the Calorimeter and the Cosmic Ray Veto due to backsplash-and-secondary interactions, and 2. To reduce radiation levels external to the Detector solenoid. The structures used in supporting the MBS will also adhere to requirements imposed by its functions. These requirements are critical to the support structures and affect design decisions. Other requirements critical to the design are imposed by the weight, positional tolerance and assembly procedure of the MBS, and also, the magnetic field and vacuum dose rate of the DS bore. A detailed breakdown of how each requirement affects the structural design can be found in chapter 2. Chapter 3 describes the design of each support structure and its attachment to the MBS while chapter 4 describes the results from structural analysis of the support structures. Chapter 5 describes evaluation for the design through testing and calculations while the conclusion in chapter 6 reports the current status at the time of this thesis submission with a plan for future work to be completed until final design and installation.

  2. Dielectric breakdown properties of SF{sub 6}-N{sub 2} mixtures at 0.01-1.6 MPa and 300-3000 K

    SciTech Connect (OSTI)

    Zhao Hu; Li Xingwen; Jia Shenli; Murphy, Anthony B.

    2013-04-14

    The dielectric breakdown properties of SF{sub 6}-N{sub 2} mixtures were investigated at different concentrations of N{sub 2}, 0.01-1.6 MPa, and 300-3000 K. The equilibrium compositions of different SF{sub 6}-N{sub 2} mixtures at several gas pressures and temperatures up to 3000 K were first calculated by minimizing the Gibbs free energy under the assumptions of local thermodynamic and chemical equilibrium. The electron energy distribution function was then obtained using the composition data by Boltzmann equation analysis. It was found that adding N{sub 2} to SF{sub 6} gas can markedly reduce the kinetic energy of electrons at relatively high gas temperatures, which enhances the dielectric field strength. Finally, the critical reduced electric field (E/N){sub cr}, defined as the value for which ionization is equal to attachment, of hot SF{sub 6}-N{sub 2} mixtures was determined. The results indicate that in the gas temperature range around 2000-3000 K, increasing the concentration of N{sub 2} effectively enhances the (E/N){sub cr} of SF{sub 6}-N{sub 2} mixtures, and the (E/N){sub cr} of SF{sub 6}-N{sub 2} mixtures at a wide range of concentrations of N{sub 2} (5%, 50%, and 95%) are all higher than that of pure SF{sub 6} gas. Further, this trend exists at all the gas pressures considered (0.01-1.6 MPa).

  3. Structural Materials

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Structural Materials Structural Materials Development enables advanced technologies through the discovery, development, and demonstration of cost-effective advanced structural materials for use in extreme environments (high-temperature, high-stress, erosive, and corrosive environments, including the performance of materials in contact with molten slags and salts). Research includes materials design and discovery, materials processing and manufacturing, and service-life prediction of materials

  4. High performance capacitors using nano-structure multilayer materials fabrication

    DOE Patents [OSTI]

    Barbee, T.W. Jr.; Johnson, G.W.; O`Brien, D.W.

    1996-01-23

    A high performance capacitor is described which is fabricated from nano-structure multilayer materials, such as by controlled, reactive sputtering, and having very high energy-density, high specific energy and high voltage breakdown. The multilayer capacitors, for example, may be fabricated in a ``notepad`` configuration composed of 200--300 alternating layers of conductive and dielectric materials so as to have a thickness of 1 mm, width of 200 mm, and length of 300 mm, with terminals at each end of the layers suitable for brazing, thereby guaranteeing low contact resistance and high durability. The ``notepad`` capacitors may be stacked in single or multiple rows (series-parallel banks) to increase the voltage and energy density. 5 figs.

  5. High performance capacitors using nano-structure multilayer materials fabrication

    DOE Patents [OSTI]

    Barbee, Jr., Troy W.; Johnson, Gary W.; O'Brien, Dennis W.

    1996-01-01

    A high performance capacitor fabricated from nano-structure multilayer materials, such as by controlled, reactive sputtering, and having very high energy-density, high specific energy and high voltage breakdown. The multilayer capacitors, for example, may be fabricated in a "notepad" configuration composed of 200-300 alternating layers of conductive and dielectric materials so as to have a thickness of 1 mm, width of 200 mm, and length of 300 mm, with terminals at each end of the layers suitable for brazing, thereby guaranteeing low contact resistance and high durability. The "notepad" capacitors may be stacked in single or multiple rows (series-parallel banks) to increase the voltage and energy density.

  6. High performance capacitors using nano-structure multilayer materials fabrication

    DOE Patents [OSTI]

    Barbee, T.W. Jr.; Johnson, G.W.; O`Brien, D.W.

    1995-05-09

    A high performance capacitor is fabricated from nano-structure multilayer materials, such as by controlled, reactive sputtering, and having very high energy-density, high specific energy and high voltage breakdown. The multilayer capacitors, for example, may be fabricated in a ``notepad`` configuration composed of 200-300 alternating layers of conductive and dielectric materials so as to have a thickness of 1 mm, width of 200 mm, and length of 300 mm, with terminals at each end of the layers suitable for brazing, thereby guaranteeing low contact resistance and high durability. The notepad capacitors may be stacked in single or multiple rows (series-parallel banks) to increase the voltage and energy density. 5 figs.

  7. High performance capacitors using nano-structure multilayer materials fabrication

    DOE Patents [OSTI]

    Barbee, Jr., Troy W.; Johnson, Gary W.; O'Brien, Dennis W.

    1995-01-01

    A high performance capacitor fabricated from nano-structure multilayer materials, such as by controlled, reactive sputtering, and having very high energy-density, high specific energy and high voltage breakdown. The multilayer capacitors, for example, may be fabricated in a "notepad" configuration composed of 200-300 alternating layers of conductive and dielectric materials so as to have a thickness of 1 mm, width of 200 mm, and length of 300 mm, with terminals at each end of the layers suitable for brazing, thereby guaranteeing low contact resistance and high durability. The "notepad" capacitors may be stacked in single or multiple rows (series-parallel banks) to increase the voltage and energy density.

  8. Breakdown by magnetic field in a La{sub 0.7}Sr{sub 0.3}MnO{sub 3}/MgO/Fe spin valve

    SciTech Connect (OSTI)

    Wu Xiaojie; Meng Jian; Zhang Zhenzhong

    2012-03-19

    A La{sub 0.7}Sr{sub 0.3}MnO{sub 3}/MgO/Fe spin valve with inverse tunneling magnetoresistance (TMR) was fabricated on a (100) SrTiO{sub 3} substrate by radio frequency magnetron sputtering. Giant TMR ratios up to 540% were obtained. The breakdown of the spin valve was observed at high magnetic field, which was attributed to the joint action of the invalidation of MgO barrier and the shift of Fermi energy in La{sub 0.7}Sr{sub 0.3}MnO{sub 3} at high magnetic field.

  9. Organizational Structure | Photosynthetic Antenna Research Center

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Organizational Structure Organizational Structure

  10. Generation of runaway electrons and X-ray emission during breakdown of atmospheric-pressure air by voltage pulses with an ∼0.5-μs front duration

    SciTech Connect (OSTI)

    Kostyrya, I. D.; Tarasenko, V. F.

    2015-03-15

    Results are presented from experiments on the generation of runaway electron beams and X-ray emission in atmospheric-pressure air by using voltage pulses with an ∼0.5-μs front duration. It is shown that the use of small-curvature-radius spherical cathodes (or other cathodes with small curvature radii) decreases the intensity of the runaway electron beam and X-ray emission. It is found that, at sufficiently high voltages at the electrode gap (U{sub m} ∼ 100 kV), the gap breakdown, the formation of a spark channel, and the generation of a runaway electron beam occur over less than 10 ns. At high values of U{sub m} behind the anode that were reached by increasing the cathode size and the electrode gap length, a supershort avalanche electron beam with a full width at half-maximum (FWHM) of up to ∼100 ps was detected. At voltages of ∼50 kV, the second breakdown regime was revealed in which a runaway electron beam with an FWHM of ∼2 ns was generated, whereas the FWHM of the X-ray pulse increased to ∼100 ns. It is established that the energy of the bulk of runaway electrons decreases with increasing voltage front duration and is ⩽30 keV in the first regime and ⩽10 keV in the second regime.

  11. Density driven structural transformations in amorphous semiconductor clathrates

    SciTech Connect (OSTI)

    Tulk, Christopher A; dos Santos, Antonio M.; Neuefeind, Joerg C; Molaison, Jamie J; Sales, Brian C; Honkimaeki, Veijo

    2015-01-01

    The pressure induced crystalline collapse at 14.7 GPa and polyamorphic structures of the semiconductor clathrate Sr8Ga16Ge30 are reported up to 35 GPa. In-situ total scattering measurements under pressure allow the direct microscopic inspection of the mechanisms associated with pressure induced amorphization in these systems, as well as the structure of the recovered phase. It is observed that, between 14.7 and 35 GPa the second peak in the structure factor function gradually disappears. Analysis of the radial distribution function extracted from those data indicate that this feature is associated with gradual cage collapse and breakdown of the tetrahedral structure with the consequent systematic lengthening of the nearest-neighbor framework bonds. This suggests an overall local coordination change to an even higher density amorphous form. Upon recovery from high pressure, the sample remains amorphous, and while there is some indication of the guest-host cage reforming, it doesn't seem that the tetrahedral coordination is recovered. As such, the compresion-decompression process in this systems gives rise to three distict amorphous forms.

  12. Density driven structural transformations in amorphous semiconductor clathrates

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Tulk, Christopher A; dos Santos, Antonio M.; Neuefeind, Joerg C; Molaison, Jamie J; Sales, Brian C; Honkimaeki, Veijo

    2015-01-01

    The pressure induced crystalline collapse at 14.7 GPa and polyamorphic structures of the semiconductor clathrate Sr8Ga16Ge30 are reported up to 35 GPa. In-situ total scattering measurements under pressure allow the direct microscopic inspection of the mechanisms associated with pressure induced amorphization in these systems, as well as the structure of the recovered phase. It is observed that, between 14.7 and 35 GPa the second peak in the structure factor function gradually disappears. Analysis of the radial distribution function extracted from those data indicate that this feature is associated with gradual cage collapse and breakdown of the tetrahedral structure with themore » consequent systematic lengthening of the nearest-neighbor framework bonds. This suggests an overall local coordination change to an even higher density amorphous form. Upon recovery from high pressure, the sample remains amorphous, and while there is some indication of the guest-host cage reforming, it doesn't seem that the tetrahedral coordination is recovered. As such, the compresion-decompression process in this systems gives rise to three distict amorphous forms.« less

  13. Nanocrystal structures

    DOE Patents [OSTI]

    Eisler, Hans J.; Sundar, Vikram C.; Walsh, Michael E.; Klimov, Victor I.; Bawendi, Moungi G.; Smith, Henry I.

    2008-12-30

    A structure including a grating and a semiconductor nanocrystal layer on the grating, can be a laser. The semiconductor nanocrystal layer can include a plurality of semiconductor nanocrystals including a Group II-VI compound, the nanocrystals being distributed in a metal oxide matrix. The grating can have a periodicity from 200 nm to 500 nm.

  14. Nanocrystal structures

    DOE Patents [OSTI]

    Eisler, Hans J.; Sundar, Vikram C.; Walsh, Michael E.; Klimov, Victor I.; Bawendi, Moungi G.; Smith, Henry I.

    2006-12-19

    A structure including a grating and a semiconductor nanocrystal layer on the grating, can be a laser. The semiconductor nanocrystal layer can include a plurality of semiconductor nanocrystals including a Group II–VI compound, the nanocrystals being distributed in a metal oxide matrix. The grating can have a periodicity from 200 nm to 500 nm.

  15. Nanocrystal structures

    DOE Patents [OSTI]

    Eisler, Hans J.; Sundar, Vikram C.; Walsh, Michael E.; Klimov, Victor I.; Bawendi, Moungi G.; Smith, Henry I.

    2006-12-19

    A structure including a grating and a semiconductor nanocrystal layer on the grating, can be a laser. The semiconductor nanocrystal layer can include a plurality of semiconductor nanocrystals including a Group IIVI compound, the nanocrystals being distributed in a metal oxide matrix. The grating can have a periodicity from 200 nm to 500 nm.

  16. Terminal structure

    DOE Patents [OSTI]

    Schmidt, Frank; Allais, Arnaud; Mirebeau, Pierre; Ganhungu, Francois; Lallouet, Nicolas

    2009-10-20

    A terminal structure (2) for a superconducting cable (1) is described. It consists of a conductor (2a) and an insulator (2b) that surrounds the conductor (2a), wherein the superconducting cable (1) has a core with a superconducting conductor (5) and a layer of insulation that surrounds the conductor (5), and wherein the core is arranged in such a way that it can move longitudinally in a cryostat. The conductor (2a) of the terminal structure (2) is electrically connected with the superconducting conductor (5) or with a normal conductor (6) that is connected with the superconducting conductor (5) by means of a tubular part (7) made of an electrically conductive material, wherein the superconducting conductor (5) or the normal conductor (6) can slide in the part (7) in the direction of the superconductor.

  17. Superconducting structure

    DOE Patents [OSTI]

    Kwon, Chuhee; Jia, Quanxi; Foltyn, Stephen R.

    2003-04-01

    A superconductive structure including a dielectric oxide substrate, a thin buffer layer of a superconducting material thereon; and, a layer of a rare earth-barium-copper oxide superconducting film thereon the thin layer of yttrium-barium-copper oxide, the rare earth selected from the group consisting of samarium, gadolinium, ytterbium, erbium, neodymium, dysprosium, holmium, lutetium, a combination of more than one element from the rare earth group and a combination of one or more elements from the rare earth group with yttrium, the buffer layer of superconducting material characterized as having chemical and structural compatibility with the dielectric oxide substrate and the rare earth-barium-copper oxide superconducting film is provided.

  18. Superconducting Structure

    DOE Patents [OSTI]

    Kwon, Chuhee; Jia, Quanxi; Foltyn, Stephen R.

    2005-09-13

    A superconductive structure including a dielectric oxide substrate, a thin buffer layer of a superconducting material thereon; and, a layer of a rare earth-barium-copper oxide superconducting film thereon the thin layer of yttrium-barium-copper oxide, the rare earth selected from the group consisting of samarium, gadolinium, ytterbium, erbium, neodymium, dysprosium, holmium, lutetium, a combination of more than one element from the rare earth group and a combination of one or more elements from the rare earth group with yttrium, the buffer layer of superconducting material characterized as having chemical and structural compatibility with the dielectric oxide substrate and the rare earth-barium-copper oxide superconducting film is provided.

  19. Functional and structural diversity in GH62 ?-L-arabinofuranosidases from the thermophilic fungus Scytalidium thermophilum

    SciTech Connect (OSTI)

    Kaur, Amrit Pal; Nocek, Boguslaw P.; Xu, Xiaohui; Lowden, Michael J.; Leyva, Juan Francisco; Stogios, Peter J.; Cui, Hong; Leo, Rosa Di; Powlowski, Justin; Tsang, Adrian; Savchenko, Alexei

    2015-05-01

    The genome of the thermophilic fungus Scytalidium thermophilum (strain CBS 625.91) harbours a wide range of genes involved in carbohydrate degradation, including three genes, abf62A, abf62B and abf62C, predicted to encode glycoside hydrolase family 62 (GH62) enzymes. Transcriptome analysis showed that only abf62A and abf62C are actively expressed during growth on diverse substrates including straws from barley, alfalfa, triticale and canola. The abf62A and abf62C genes were expressed in Escherichia coli and the resulting recombinant proteins were characterized. Calcium-free crystal structures of Abf62C in apo and xylotriose bound forms were determined to 1.23 and 1.48 resolution respectively. Site-directed mutagenesis confirmed Asp55, Asp171 and Glu230 as catalytic triad residues, and revealed the critical role of non-catalytic residues Asp194, Trp229 and Tyr338 in positioning the scissile ?-L-arabinofuranoside bond at the catalytic site. Further, the +2R substrate-binding site residues Tyr168 and Asn339, as well as the +2NR residue Tyr226, are involved in accommodating long-chain xylan polymers. Overall, our structural and functional analysis highlights characteristic differences between Abf62A and Abf62C, which represent divergent subgroups in the GH62 family.

  20. Suppression of beam induced pulse shortening modes in high power RF generator TW output structures

    SciTech Connect (OSTI)

    Haimson, J.; Mecklenburg, B.

    1992-12-31

    Several different style 11.4 GHz relativistic klystrons, operating with beam pulse widths of 50 ns and using large aperture, tapered phase-velocity TW structures,` have recently demonstrated output RF power levels in the range of 100 to 300 MW without breakdown or pulse shortening. To extend this performance into the long pulse regime (1 {mu}s) or to demonstrate a threefold increase in output power by using higher currents, the existing TW circuit designs must be modified (a) to reduce the cavity maximum surface E-fields by a factor of 2 to 3, and (b) to elevate the current threshold values of the beam induced higher order modes (HOM) to ensure avoidance of RF pulse shortening and associated instabilities. A technique for substantially elevating this threshold current is described, and microwave data and photographs are presented showing the degree of HOM damping achieved in a recently constructed 11.4 GHz TW structure.

  1. Airfoil structure

    DOE Patents [OSTI]

    Frey, Gary A.; Twardochleb, Christopher Z.

    1998-01-01

    Past airfoil configurations have been used to improve aerodynamic performance and engine efficiencies. The present airfoil configuration further increases component life and reduces maintenance by reducing internal stress within the airfoil itself. The airfoil includes a chord and a span. Each of the chord and the span has a bow being summed to form a generally "C" configuration of the airfoil. The generally "C" configuration includes a compound bow in which internal stresses resulting from a thermal temperature gradient are reduced. The structural configuration reduces internal stresses resulting from thermal expansion.

  2. Airfoil structure

    DOE Patents [OSTI]

    Frey, G.A.; Twardochleb, C.Z.

    1998-01-13

    Past airfoil configurations have been used to improve aerodynamic performance and engine efficiencies. The present airfoil configuration further increases component life and reduces maintenance by reducing internal stress within the airfoil itself. The airfoil includes a chord and a span. Each of the chord and the span has a bow being summed to form a generally ``C`` configuration of the airfoil. The generally ``C`` configuration includes a compound bow in which internal stresses resulting from a thermal temperature gradient are reduced. The structural configuration reduces internal stresses resulting from thermal expansion. 6 figs.

  3. Evaluation of a commercially available passively Q-switched Nd:YAG laser with LiF:F-2 saturable absorber for laser-induced breakdown spectroscopy

    SciTech Connect (OSTI)

    Carson, Cantwell; Goueguel, Christian; Sanghapi, Herve; Jinesh, Jain; McIntyre, Dustin

    2015-12-11

    Interest in passively Q-switched microchip lasers as a means for miniaturization of laser-induced breakdown spectroscopy (LIBS) apparatus has rapidly grown in the last years. To explore the possibility of using a comparatively UV–vis transparent absorber, we herein present the first report on the evaluation of a commercially available flash lamp-pumped passively Q-switched Nd:YAG laser with LiF: saturable absorber as an excitation source in LIBS. Quantitative measurements of barium, strontium, rubidium and lithium in granite, rhyolite, basalt and syenite whole-rock glass samples were performed. Using a gated intensified benchtop spectrometer, limits of detection of 0.97, 23, 37, and 144 ppm were obtained for Li, Sr, Rb, and Ba, respectively. Finally, we discuss the advantages of using such a laser unit for LIBS applications in terms of ablation efficiency, analytical performances, output energy, and standoff capabilities.

  4. Armor structures

    DOE Patents [OSTI]

    Chu, Henry Shiu-Hung [Idaho Falls, ID; Lacy, Jeffrey M [Idaho Falls, ID

    2008-04-01

    An armor structure includes first and second layers individually containing a plurality of i-beams. Individual i-beams have a pair of longitudinal flanges interconnected by a longitudinal crosspiece and defining opposing longitudinal channels between the pair of flanges. The i-beams within individual of the first and second layers run parallel. The laterally outermost faces of the flanges of adjacent i-beams face one another. One of the longitudinal channels in each of the first and second layers faces one of the longitudinal channels in the other of the first and second layers. The channels of the first layer run parallel with the channels of the second layer. The flanges of the first and second layers overlap with the crosspieces of the other of the first and second layers, and portions of said flanges are received within the facing channels of the i-beams of the other of the first and second layers.

  5. Synthesis, crystal structure, resistivity, and electronic structure...

    Office of Scientific and Technical Information (OSTI)

    Synthesis, crystal structure, resistivity, and electronic structure of the U(V) quaternary ... and electronic structure of the U(V) quaternary polyselenide Ba8PdU2Se12(Se2)2 ...

  6. Structural Health Monitoring

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Structural Health Monitoring Engineering Institute Structural Health Monitoring Structural Health Monitoring is the process of implementing a damage detection strategy for...

  7. Stormwater Control Structures

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Stormwater Control Structures Stormwater Control Structures Stormwater control structures are engineered to control run-on and runoff water from suspected contaminated sites. ...

  8. Cropland Field Monitoring: MMV Page 1 Montana Cropland Enrolled Farm Fields Carbon Sequestration Field Sampling, Measurement, Monitoring, and Verification: Application of Visible-Near Infrared Diffuse Reflectance Spectroscopy (VNIR) and Laser-induced Breakdown Spectroscopy (LIBS)

    SciTech Connect (OSTI)

    Lee Spangler; Ross Bricklemyer; David Brown

    2012-03-15

    There is growing need for rapid, accurate, and inexpensive methods to measure, and verify soil organic carbon (SOC) change for national greenhouse gas accounting and the development of a soil carbon trading market. Laboratory based soil characterization typically requires significant soil processing, which is time and resource intensive. This severely limits application for large-region soil characterization. Thus, development of rapid and accurate methods for characterizing soils are needed to map soil properties for precision agriculture applications, improve regional and global soil carbon (C) stock and flux estimates and efficiently map sub-surface metal contamination, among others. The greatest gains for efficient soil characterization will come from collecting soil data in situ, thus minimizing soil sample transportation, processing, and lab-based measurement costs. Visible and near-infrared diffuse reflectance spectroscopy (VisNIR) and laser-induced breakdown spectroscopy (LIBS) are two complementary, yet fundamentally different spectroscopic techniques that have the potential to meet this need. These sensors have the potential to be mounted on a soil penetrometer and deployed for rapid soil profile characterization at field and landscape scales. Details of sensor interaction, efficient data management, and appropriate statistical analysis techniques for model calibrations are first needed. In situ or on-the-go VisNIR spectroscopy has been proposed as a rapid and inexpensive tool for intensively mapping soil texture and organic carbon (SOC). While lab-based VisNIR has been established as a viable technique for estimating various soil properties, few experiments have compared the predictive accuracy of on-the-go and lab-based VisNIR. Eight north central Montana wheat fields were intensively interrogated using on-the-go and lab-based VisNIR. Lab-based spectral data consistently provided more accurate predictions than on-the-go data. However, neither in situ

  9. Magnetic multilayer structure

    DOE Patents [OSTI]

    Herget, Philipp; O'Sullivan, Eugene J.; Romankiw, Lubomyr T.; Wang, Naigang; Webb, Bucknell C.

    2016-07-05

    A mechanism is provided for an integrated laminated magnetic device. A substrate and a multilayer stack structure form the device. The multilayer stack structure includes alternating magnetic layers and diode structures formed on the substrate. Each magnetic layer in the multilayer stack structure is separated from another magnetic layer in the multilayer stack structure by a diode structure.

  10. An apparatus for studying electrical breakdown in liquid helium at 0.4 K and testing electrode materials for the neutron electric dipole moment experiment at the Spallation Neutron Source

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ito, T. M.; Ramsey, J. C.; Yao, W.; Beck, D. H.; Cianciolo, V.; Clayton, S. M.; Crawford, C.; Currie, S. A.; Filippone, B. W.; Griffith, W. C.; et al

    2016-04-25

    In this study, we have constructed an apparatus to study DC electrical breakdown in liquid helium at temperatures as low as 0.4 K and at pressures between the saturated vapor pressure and ~600 Torr. The apparatus can house a set of electrodes that are 12 cm in diameter with a gap of 1–2 cm between them, and a potential up to ±50 kV can be applied to each electrode. Initial results demonstrated that it is possible to apply fields exceeding 100 kV/cm in a 1 cm gap between two electropolished stainless steel electrodes 12 cm in diameter for a widemore » range of pressures at 0.4 K. We also measured the current between two electrodes. Our initial results, I < 1 pA at 45 kV, correspond to a lower bound on the effective volume resistivity of liquid helium of ρV > 5 × 1018 Ω cm. This lower bound is 5 times larger than the bound previously measured. Finally, we report the design, construction, and operational experience of the apparatus, as well as initial results« less

  11. Liquid effluents program FY 1997 multi-year work plan

    SciTech Connect (OSTI)

    Green, F.T.

    1996-09-30

    This document provides the technical baseline and work breakdown structure for the liquid effluents program.

  12. Variably porous structures

    DOE Patents [OSTI]

    Braun, Paul V.; Yu, Xindi

    2011-01-18

    A method of making a monolithic porous structure, comprises electrodepositing a material on a template; removing the template from the material to form a monolithic porous structure comprising the material; and electropolishing the monolithic porous structure.

  13. Structural Molecular Biology, SSRL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Workshops & Summer Schools Summer Students Structural Molecular Biology Illuminating ... major experimental driver for structural biology research, serving the needs of a large ...

  14. coherent-structures-html

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Role of Coherent Structures in Scour Process Around Bridge Piers and Abutments

  15. Resilience of complex networks to random breakdown

    SciTech Connect (OSTI)

    Paul, Gerald; Sreenivasan, Sameet; Stanley, H. Eugene

    2005-11-01

    Using Monte Carlo simulations we calculate f{sub c}, the fraction of nodes that are randomly removed before global connectivity is lost, for networks with scale-free and bimodal degree distributions. Our results differ from the results predicted by an equation for f{sub c} proposed by Cohen et al. We discuss the reasons for this disagreement and clarify the domain for which the proposed equation is valid.

  16. Ion manipulation device with electrical breakdown protection

    DOE Patents [OSTI]

    Chen, Tsung-Chi; Tang, Keqi; Ibrahim, Yehia M; Smith, Richard D; Anderson, Gordon A; Baker, Erin M

    2014-12-02

    An ion manipulation method and device is disclosed. The device includes a pair of substantially parallel surfaces. An array of inner electrodes is contained within, and extends substantially along the length of, each parallel surface. The device includes a first outer array of electrodes and a second outer array of electrodes. Each outer array of electrodes is positioned on either side of the inner electrodes, and is contained within and extends substantially along the length of each parallel surface. A DC voltage is applied to the first and second outer array of electrodes. A RF voltage, with a superimposed electric field, is applied to the inner electrodes by applying the DC voltages to each electrode. Ions either move between the parallel surfaces within an ion confinement area or along paths in the direction of the electric field, or can be trapped in the ion confinement area. The surfaces are housed in a chamber, and at least one electrically insulative shield is coupled to an inner surface of the chamber for increasing a mean-free-path between two adjacent electrodes in the chamber.

  17. Structural system identification: Structural dynamics model validation

    SciTech Connect (OSTI)

    Red-Horse, J.R.

    1997-04-01

    Structural system identification is concerned with the development of systematic procedures and tools for developing predictive analytical models based on a physical structure`s dynamic response characteristics. It is a multidisciplinary process that involves the ability (1) to define high fidelity physics-based analysis models, (2) to acquire accurate test-derived information for physical specimens using diagnostic experiments, (3) to validate the numerical simulation model by reconciling differences that inevitably exist between the analysis model and the experimental data, and (4) to quantify uncertainties in the final system models and subsequent numerical simulations. The goal of this project was to develop structural system identification techniques and software suitable for both research and production applications in code and model validation.

  18. Civil Engineer (Structural)

    Broader source: Energy.gov [DOE]

    This position is located in Structural Design (TELD). The primary purpose of this position is to serve as a senior engineer responsible for loading, design, and analysis of all structures on BPA's...

  19. Structural health monitoring for ship structures

    SciTech Connect (OSTI)

    Farrar, Charles; Park, Gyuhae; Angel, Marian; Bement, Matthew; Salvino, Liming

    2009-01-01

    Currently the Office of Naval Research is supporting the development of structural health monitoring (SHM) technology for U.S. Navy ship structures. This application is particularly challenging because of the physical size of these structures, the widely varying and often extreme operational and environmental conditions associated with these ships missions, lack of data from known damage conditions, limited sensing that was not designed specifically for SHM, and the management of the vast amounts of data that can be collected during a mission. This paper will first define a statistical pattern recognition paradigm for SHM by describing the four steps of (1) Operational Evaluation, (2) Data Acquisition, (3) Feature Extraction, and (4) Statistical Classification of Features as they apply to ship structures. Note that inherent in the last three steps of this process are additional tasks of data cleansing, compression, normalization and fusion. The presentation will discuss ship structure SHM challenges in the context of applying various SHM approaches to sea trials data measured on an aluminum multi-hull high-speed ship, the HSV-2 Swift. To conclude, the paper will discuss several outstanding issues that need to be addressed before SHM can make the transition from a research topic to actual field applications on ship structures and suggest approaches for addressing these issues.

  20. Stormwater Control Structures

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Stormwater Control Structures Stormwater Control Structures Stormwater control structures are engineered to control run-on and runoff water from suspected contaminated sites. Structures trap sediment, keep water on-site, slow water flow and redirect water around problem areas. Rock check dams Rock check dams Silt tence Silt fence Sediment trap Sediment trap Wood mulch and native seed Wood mulch and native seed Gabion Gabion Concrete lined swales Concrete lined swales Hydroseeding Hydroseeding

  1. Neutron reflecting supermirror structure

    DOE Patents [OSTI]

    Wood, James L.

    1992-01-01

    An improved neutron reflecting supermirror structure comprising a plurality of stacked sets of bilayers of neutron reflecting materials. The improved neutron reflecting supermirror structure is adapted to provide extremely good performance at high incidence angles, i.e. up to four time the critical angle of standard neutron mirror structures. The reflection of neutrons striking the supermirror structure at a high critical angle provides enhanced neutron throughput, and hence more efficient and economical use of neutron sources.

  2. Neutron reflecting supermirror structure

    DOE Patents [OSTI]

    Wood, J.L.

    1992-12-01

    An improved neutron reflecting supermirror structure comprising a plurality of stacked sets of bilayers of neutron reflecting materials. The improved neutron reflecting supermirror structure is adapted to provide extremely good performance at high incidence angles, i.e. up to four time the critical angle of standard neutron mirror structures. The reflection of neutrons striking the supermirror structure at a high critical angle provides enhanced neutron throughput, and hence more efficient and economical use of neutron sources. 2 figs.

  3. Computational Structural Mechanics

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    load-2 TRACC RESEARCH Computational Fluid Dynamics Computational Structural Mechanics Transportation Systems Modeling Computational Structural Mechanics Overview of CSM Computational structural mechanics is a well-established methodology for the design and analysis of many components and structures found in the transportation field. Modern finite-element models (FEMs) play a major role in these evaluations, and sophisticated software, such as the commercially available LS-DYNA® code, is

  4. Cambridge Structural Database

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Cambridge Structural Database Cambridge Structural Database Los Alamos researchers can access WebCSD from offsite via Remote Access. Question? 667-5809 Email Cambridge Structural Database (CSD) includes bibliographic, chemical, and crystallographic information for organic molecules and metal-organic compounds. The crystal structure data comes from the open literature or direct deposits by researchers. The CSD System incorporations a suite of flexible search and analysis tools. The Research

  5. Railway vehicle body structures

    SciTech Connect (OSTI)

    Not Available

    1985-01-01

    The strength and durability of railway vehicle structures is a major topic of engineering research and design. To reflect this importance the Railway Division of the Institution of Mechanical Engineers organised a conference to discuss all matters relating to railway vehicle design. This book presents the papers discussed in that conference. The contents include: Vehicle body design and the UIC's international contribution; LUL prototype 1986 stock - body structure; vehicle structure for the intermediate capacity transmit system vehicles; car body technology of advanced light rapid transit vehicles; concepts, techniques and experience in the idealization of car body structures for finite element analysis; Calcutta metropolitan railway; design for a lightweight diesel multiple unit body; the design of lightweight inter-city coal structures; the BREL international coach body shell structure; new concepts and design techniques versus material standards; structures of BR diesel electric freight locomotives; structural design philosophy for electric locomotives; suspension design for a locomotive with low structural frequencies; freight wagon structures; a finite element study of coal bodyside panels including the effects of joint flexibility; a fresh approach to the problem of car body design strength; energy absorption in automatic couplings and draw gear; passenger vehicle design loads and structural crashworthiness; design of the front part of railway vehicles (in case of frontal impact); the development of a theoretical technique for rail vehicle structural crashworthiness.

  6. Vitrified underground structures

    DOE Patents [OSTI]

    Murphy, Mark T.; Buelt, James L.; Stottlemyre, James A.; Tixier, Jr., John S.

    1992-01-01

    A method of making vitrified underground structures in which 1) the vitrification process is started underground, and 2) a thickness dimension is controlled to produce substantially planar vertical and horizontal vitrified underground structures. Structures may be placed around a contaminated waste site to isolate the site or may be used as aquifer dikes.

  7. Catalytic distillation structure

    DOE Patents [OSTI]

    Smith, Jr., Lawrence A.

    1984-01-01

    Catalytic distillation structure for use in reaction distillation columns, a providing reaction sites and distillation structure and consisting of a catalyst component and a resilient component intimately associated therewith. The resilient component has at least about 70 volume % open space and being present with the catalyst component in an amount such that the catalytic distillation structure consist of at least 10 volume % open space.

  8. BOMB STABILIZING STRUCTURE

    DOE Patents [OSTI]

    Kelley, J.L.; Runyan, C.E.

    1963-12-10

    A stabilizinig structure capable of minimizing deviations of a falling body such as a bomb from desired trajectory is described. The structure comprises a fin or shroud arrangement of double-wedge configuration, the feeding portion being of narrow wedge shape and the after portion being of a wider wedge shape. The structure provides a force component for keeping the body on essentially desired trajectory throughout its fall. (AEC)

  9. Undergraduate Program Salary Structure

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Salary Structure Undergraduate Program Salary Structure Point your career towards Los Alamos Lab: work with the best minds on the planet in an inclusive environment that is rich in intellectual vitality and opportunities for growth. Contact Student Programs (505) 665-0964 Email Undergraduate salary determination process Salaries are evaluated from students' current transcripts based on college academic progression and hours completed in a degree program. Professional Salary Structure Years

  10. Catalytic distillation structure

    DOE Patents [OSTI]

    Smith, L.A. Jr.

    1984-04-17

    Catalytic distillation structure is described for use in reaction distillation columns, and provides reaction sites and distillation structure consisting of a catalyst component and a resilient component intimately associated therewith. The resilient component has at least about 70 volume % open space and is present with the catalyst component in an amount such that the catalytic distillation structure consists of at least 10 volume % open space. 10 figs.