National Library of Energy BETA

Sample records for tion-carbon dioxide helium

  1. Helium Migration Mechanisms in Polycrystalline Uranium Dioxide

    SciTech Connect

    Martin, Guillaume; Desgardin, Pierre; Sauvage, Thierry; Barthe, Marie-France; Garcia, Philippe; Carlot, Gaelle

    2007-07-01

    This study aims at identifying the release mechanisms of helium in uranium dioxide. Two sets of polycrystalline UO{sub 2} sintered samples presenting different microstructures were implanted with {sup 3}He ions at concentrations in the region of 0.1 at.%. Changes in helium concentrations were monitored using two Nuclear Reaction Analysis (NRA) techniques based on the {sup 3}He(d,{alpha}){sup 1}H reaction. {sup 3}He release is measured in-situ during sample annealing at temperatures ranging between 700 deg. C and 1000 deg. C. Accurate helium depth profiles are generated after each annealing stage. Results that provide data for further understanding helium release mechanisms are discussed. It is found that helium diffusion appears to be enhanced above 900 deg. C in the vicinity of grain boundaries possibly as a result of the presence of defects. (authors)

  2. Coupling a Supercritical Carbon Dioxide Brayton Cycle to a Helium-Cooled Reactor.

    SciTech Connect

    Middleton, Bobby; Pasch, James Jay; Kruizenga, Alan Michael; Walker, Matthew

    2016-01-01

    This report outlines the thermodynamics of a supercritical carbon dioxide (sCO2) recompression closed Brayton cycle (RCBC) coupled to a Helium-cooled nuclear reactor. The baseline reactor design for the study is the AREVA High Temperature Gas-Cooled Reactor (HTGR). Using the AREVA HTGR nominal operating parameters, an initial thermodynamic study was performed using Sandia's deterministic RCBC analysis program. Utilizing the output of the RCBC thermodynamic analysis, preliminary values of reactor power and of Helium flow rate through the reactor were calculated in Sandia's HelCO2 code. Some research regarding materials requirements was then conducted to determine aspects of corrosion related to both Helium and to sCO2 , as well as some mechanical considerations for pressures and temperatures that will be seen by the piping and other components. This analysis resulted in a list of materials-related research items that need to be conducted in the future. A short assessment of dry heat rejection advantages of sCO2> Brayton cycles was also included. This assessment lists some items that should be investigated in the future to better understand how sCO2 Brayton cycles and nuclear can maximally contribute to optimizing the water efficiency of carbon free power generation

  3. Metal tritides helium emission

    SciTech Connect

    Beavis, L.C.

    1980-02-01

    Over the past several years, we have been measuring the release of helium from metal tritides (primarily erbium tritide). We find that qualitatively all tritides of interest to us behave the same. When they are first formed, the helium is released at a low rate that appears to be related to the amount of surface area which has access to the outside of the material (either film or bulk). For example, erbium tritide films initially release about 0.3% of the helium generated. Most tritide films emit helium at about this rate initially. At some later time, which depends upon the amount of helium generated, the parent occluding element and the degree of tritium saturation of the dihydride phase the helium emission changes to a new mode in which it is released at approximately the rate at which it is generated (for example, we measure this value to be approx. = .31 He/Er for ErT/sub 1/./sub 9/ films). If erbium ditritide is saturated beyond 1.9 T/Er, the critical helium/metal ratio decreases. For example, in bulk powders ErT/sub 2/./sub 15/ reaches critical release concentration at approx. = 0.03. Moderate elevation of temperature above room temperature has little impact on the helium release rate. It appears that the process may have approx. = 2 kcal/mol activation energy. The first helium formed is well bound. As the tritide ages, the helium is found in higher energy sites. Similar but less extensive measurements on scandium, titanium, and zirconium tritides are also described. Finally, the thermal desorption of erbium tritides of various ages from 50 days to 3154 days is discussed. Significant helium is desorbed along with the tritium in all but the youngest samples during thermodesorption.

  4. Helium Energy | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    Energy Jump to: navigation, search Name: Helium Energy Place: Spain Sector: Renewable Energy Product: Spain-based renewable energy development company. References: Helium Energy1...

  5. Bisphosphine dioxides

    DOEpatents

    Moloy, Kenneth G.

    1990-01-01

    A process for the production of organic bisphosphine dioxides from organic bisphosphonates. The organic bisphosphonate is reacted with a Grignard reagent to give relatively high yields of the organic bisphosphine dioxide.

  6. Bisphosphine dioxides

    DOEpatents

    Moloy, K.G.

    1990-02-20

    A process is described for the production of organic bisphosphine dioxides from organic bisphosphonates. The organic bisphosphonate is reacted with a Grignard reagent to give relatively high yields of the organic bisphosphine dioxide.

  7. Is solid helium a supersolid?

    SciTech Connect

    Hallock, Robert

    2015-05-15

    Recent experiments suggest that helium-4 atoms can flow through an experimental cell filled with solid helium. But that incompletely understood flow is quite different from the reported superfluid-like motion that so excited physicists a decade ago.

  8. Electron Bubbles in Liquid Helium

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Electron Bubbles in Liquid Helium and Quantum Mechanics Humphrey J. Maris Brown University September 16, 2015 4:00 p.m. An electron entering liquid helium forces open a cavity referred to as an electron bubble. These objects have been studied in many past experiments and appear to be well understood. However, experiments have revealed that in addition to these normal electron bubbles there are other negatively charged objects in liquid helium. Despite much effort the structure of these so-called

  9. Helium dilution refrigeration system

    DOEpatents

    Roach, P.R.; Gray, K.E.

    1988-09-13

    A helium dilution refrigeration system operable over a limited time period, and recyclable for a next period of operation is disclosed. The refrigeration system is compact with a self-contained pumping system and heaters for operation of the system. A mixing chamber contains [sup 3]He and [sup 4]He liquids which are precooled by a coupled container containing [sup 3]He liquid, enabling the phase separation of a [sup 3]He rich liquid phase from a dilute [sup 3]He-[sup 4]He liquid phase which leads to the final stage of a dilution cooling process for obtaining low temperatures. The mixing chamber and a still are coupled by a fluid line and are maintained at substantially the same level with the still cross sectional area being smaller than that of the mixing chamber. This configuration provides maximum cooling power and efficiency by the cooling period ending when the [sup 3]He liquid is depleted from the mixing chamber with the mixing chamber nearly empty of liquid helium, thus avoiding unnecessary and inefficient cooling of a large amount of the dilute [sup 3]He-[sup 4]He liquid phase. 2 figs.

  10. Helium dilution refrigeration system

    DOEpatents

    Roach, Patrick R.; Gray, Kenneth E.

    1988-01-01

    A helium dilution refrigeration system operable over a limited time period, and recyclable for a next period of operation. The refrigeration system is compact with a self-contained pumping system and heaters for operation of the system. A mixing chamber contains .sup.3 He and .sup.4 He liquids which are precooled by a coupled container containing .sup.3 He liquid, enabling the phase separation of a .sup.3 He rich liquid phase from a dilute .sup.3 He-.sup.4 He liquid phase which leads to the final stage of a dilution cooling process for obtaining low temperatures. The mixing chamber and a still are coupled by a fluid line and are maintained at substantially the same level with the still cross sectional area being smaller than that of the mixing chamber. This configuration provides maximum cooling power and efficiency by the cooling period ending when the .sup.3 He liquid is depleted from the mixing chamber with the mixing chamber nearly empty of liquid helium, thus avoiding unnecessary and inefficient cooling of a large amount of the dilute .sup.3 He-.sup.4 He liquid phase.

  11. Carbon Dioxide and Helium Emissions from a Reservoir of Magmatic...

    OpenEI (Open Energy Information) [EERE & EIA]

    in eastern California. The gas is released mainly as diffuse emissions from normal-temperature soils, but some gas issues from steam vents or leaves the mountain dissolved...

  12. ITER helium ash accumulation

    SciTech Connect

    Hogan, J.T.; Hillis, D.L.; Galambos, J.; Uckan, N.A. ); Dippel, K.H.; Finken, K.H. . Inst. fuer Plasmaphysik); Hulse, R.A.; Budny, R.V. . Plasma Physics Lab.)

    1990-01-01

    Many studies have shown the importance of the ratio {upsilon}{sub He}/{upsilon}{sub E} in determining the level of He ash accumulation in future reactor systems. Results of the first tokamak He removal experiments have been analysed, and a first estimate of the ratio {upsilon}{sub He}/{upsilon}{sub E} to be expected for future reactor systems has been made. The experiments were carried out for neutral beam heated plasmas in the TEXTOR tokamak, at KFA/Julich. Helium was injected both as a short puff and continuously, and subsequently extracted with the Advanced Limiter Test-II pump limiter. The rate at which the He density decays has been determined with absolutely calibrated charge exchange spectroscopy, and compared with theoretical models, using the Multiple Impurity Species Transport (MIST) code. An analysis of energy confinement has been made with PPPL TRANSP code, to distinguish beam from thermal confinement, especially for low density cases. The ALT-II pump limiter system is found to exhaust the He with maximum exhaust efficiency (8 pumps) of {approximately}8%. We find 1<{upsilon}{sub He}/{upsilon}{sub E}<3.3 for the database of cases analysed to date. Analysis with the ITER TETRA systems code shows that these values would be adequate to achieve the required He concentration with the present ITER divertor He extraction system.

  13. Pulsed helium ionization detection system

    DOEpatents

    Ramsey, Roswitha S. (Knoxville, TN); Todd, Richard A. (Knoxville, TN)

    1987-01-01

    A helium ionization detection system is provided which produces stable operation of a conventional helium ionization detector while providing improved sensitivity and linearity. Stability is improved by applying pulsed dc supply voltage across the ionization detector, thereby modifying the sampling of the detectors output current. A unique pulse generator is used to supply pulsed dc to the detector which has variable width and interval adjust features that allows up to 500 V to be applied in pulse widths ranging from about 150 nsec to about dc conditions.

  14. Pulsed helium ionization detection system

    DOEpatents

    Ramsey, R.S.; Todd, R.A.

    1985-04-09

    A helium ionization detection system is provided which produces stable operation of a conventional helium ionization detector while providing improved sensitivity and linearity. Stability is improved by applying pulsed dc supply voltage across the ionization detector, thereby modifying the sampling of the detectors output current. A unique pulse generator is used to supply pulsed dc to the detector which has variable width and interval adjust features that allows up to 500 V to be applied in pulse widths ranging from about 150 nsec to about dc conditions.

  15. Nitrogen dioxide detection

    DOEpatents

    Sinha, Dipen N.; Agnew, Stephen F.; Christensen, William H.

    1993-01-01

    Method and apparatus for detecting the presence of gaseous nitrogen dioxide and determining the amount of gas which is present. Though polystyrene is normally an insulator, it becomes electrically conductive in the presence of nitrogen dioxide. Conductance or resistance of a polystyrene sensing element is related to the concentration of nitrogen dioxide at the sensing element.

  16. Energy, helium, and the future: II

    SciTech Connect

    Krupka, M.C.; Hammel, E.F.

    1980-01-01

    The importance of helium as a critical resource material has been recognized specifically by the scientific community and more generally by the 1960 Congressional mandate to institute a long-range conservation program. A major study mandated by the Energy Reorganization Act of 1974 resulted in the publication in 1975 of the document, The Energy-Related Applications of Helium, ERDA-13. This document contained a comprehensive review and analysis relating to helium resources and present and future supply/demand relationships with particular emphasis upon those helium-dependent energy-related technologies projected to be implemented in the post-2000 year time period, e.g., fusion. An updated overview of the helium situation as it exists today is presented. Since publication of ERDA-13, important changes in the data base underlying that document have occurred. The data have since been reexamined, revised, and new information included. Potential supplies of helium from both conventional and unconventional natural gas resources, projected supply/demand relationships to the year 2030 based upon a given power-generation scenario, projected helium demand for specific energy-related technologies, and the supply options (national and international) available to meet that demand are discussed. An updated review will be given of the energy requirements for the extraction of helium from natural gas as they relate to the concentration of helium. A discussion is given concerning the technical and economic feasibility of several methods available both now and conceptually possible, to extract helium from helium-lean natural gas, the atmosphere, and outer space. Finally, a brief review is given of the 1980 Congressional activities with respect to the introduction and possible passage of new helium conservation legislation.

  17. Double, Double Toil and Trouble: Tungsten Burns and Helium Bubbles...

    Office of Science (SC)

    Helium bubbles are detrimental to plasma-facing materials such as tungsten in fusion reactors, which could serve as a possible new power source. Thus, understanding how helium ...

  18. Surprisingly Large Generation and Retention of Helium and Hydrogen...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Surprisingly Large Generation and Retention of Helium and Hydrogen in ... Title: Surprisingly Large Generation and Retention of Helium and Hydrogen in Pure Nickel ...

  19. Carbon Dioxide Utilization Summit

    Energy.gov [DOE]

    The 6th Carbon Dioxide Utilization Summit will be held in Newark, New Jersey, from Feb. 24–26, 2016. The conference will look at the benefits and challenges of carbon dioxide utilization. Advanced Algal Systems Program Manager Alison Goss Eng and Technology Manager Devinn Lambert will be in attendance. Dr. Goss Eng will be chairing a round table on Fuels and Chemicals during the Carbon Dioxide Utilization: From R&D to Commercialization discussion session.

  20. Helium refrigeration considerations for cryomodule design

    SciTech Connect

    Ganni, V.; Knudsen, P.

    2014-01-29

    Many of the present day accelerators are based on superconducting radio frequency (SRF) cavities, packaged in cryo-modules (CM), which depend on helium refrigeration at sub-atmospheric pressures, nominally 2 K. These specialized helium refrigeration systems are quite cost intensive to produce and operate. Particularly as there is typically no work extraction below the 4.5-K supply, it is important that the exergy loss between this temperature level and the CM load temperature(s) be minimized by the process configuration choices. This paper will present, compare and discuss several possible helium distribution process arrangements to support the CM loads.

  1. Method for dissolving plutonium dioxide

    DOEpatents

    Tallent, Othar K.

    1976-01-01

    A method for dissolving plutonium dioxide comprises adding silver ions to a nitric acid-hydrofluoric acid solution to significantly speed up dissolution of difficultly soluble plutonium dioxide.

  2. Future Sulfur Dioxide Emissions

    SciTech Connect

    Smith, Steven J.; Pitcher, Hugh M.; Wigley, Tom M.

    2005-12-01

    The importance of sulfur dioxide emissions for climate change is now established, although substantial uncertainties remain. This paper presents projections for future sulfur dioxide emissions using the MiniCAM integrated assessment model. A new income-based parameterization for future sulfur dioxide emissions controls is developed based on purchasing power parity (PPP) income estimates and historical trends related to the implementation of sulfur emissions limitations. This parameterization is then used to produce sulfur dioxide emissions trajectories for the set of scenarios developed for the Special Report on Emission Scenarios (SRES). We use the SRES methodology to produce harmonized SRES scenarios using the latest version of the MiniCAM model. The implications, and requirements, for IA modeling of sulfur dioxide emissions are discussed. We find that sulfur emissions eventually decline over the next century under a wide set of assumptions. These emission reductions result from a combination of emission controls, the adoption of advanced electric technologies, and a shift away from the direct end use of coal with increasing income levels. Only under a scenario where incomes in developing regions increase slowly do global emission levels remain at close to present levels over the next century. Under a climate policy that limits emissions of carbon dioxide, sulfur dioxide emissions fall in a relatively narrow range. In all cases, the relative climatic effect of sulfur dioxide emissions decreases dramatically to a point where sulfur dioxide is only a minor component of climate forcing by the end of the century. Ecological effects of sulfur dioxide, however, could be significant in some developing regions for many decades to come.

  3. Tritium-helium effects in metals

    SciTech Connect

    Caskey, G.R.

    1985-09-01

    Investigations of helium effects in metals at the Savannah River Laboratory have been carried out by introducing helium by radioactive decay of tritium. This process does not create concurrent radiation damage, such as accompanies ion implantation and (n,..cap alpha..) reactions. The process has its own peculiarities, however, which partially mask and interact with the helium effect of interest. The distribution and local concentration of helium and tritium, which are responsible for changes in mechanical properties and fracture mode, are controlled by the large difference in solubility and diffusivity between the two atoms and by their differing interaction energies with lattice defects, impurities, and internal boundaries. Furthermore, in all investigations with helium generated from tritium decay, some tritium and deuterium are always present. Consequently, property changes include tritium-helium interaction effects to some extent. Results of investigations with several austenitic stainless steels, Armco iron, and niobium single crystals illustrate the variety of phenomena and some of the complex interactions that can be encountered.

  4. Tritium-helium effects in metals

    SciTech Connect

    Caskey, G.R. Jr.

    1985-01-01

    Investigations of helium effects in metals at the Savannah River Laboratory have been carried out by introducing helium by radioactive decay of tritium. This process does not create concurrent radiation damage, such as accompanies ion implantation and (n,..cap alpha..) reactions. The process has its own peculiarities, however, which partially mask and interact with the helium effect of interest. The distribution and local concentration of helium and tritium, which are responsible for changes in mechanical properties and fracture mode, are controlled by the large difference in solubility and diffusivity between the two atoms and by their differing interaction energies with lattice defects, impurities, and internal boundaries. Furthermore, in all investigations with helium generated from tritium decay, some tritium and deuterium are always present. Consequently, property changes include tritium-helium interaction effects to some extent. Results of investigations with several austenitic stainless steels, Armco iron, and niobium single crystals illustrate the variety of phenomena and some of the complex interactions that can be encountered.

  5. Carbon dioxide removal process

    DOEpatents

    Baker, Richard W.; Da Costa, Andre R.; Lokhandwala, Kaaeid A.

    2003-11-18

    A process and apparatus for separating carbon dioxide from gas, especially natural gas, that also contains C.sub.3+ hydrocarbons. The invention uses two or three membrane separation steps, optionally in conjunction with cooling/condensation under pressure, to yield a lighter, sweeter product natural gas stream, and/or a carbon dioxide stream of reinjection quality and/or a natural gas liquids (NGL) stream.

  6. TRANSPARENT HELIUM IN STRIPPED ENVELOPE SUPERNOVAE

    SciTech Connect

    Piro, Anthony L.; Morozova, Viktoriya S., E-mail: piro@caltech.edu [Theoretical Astrophysics, California Institute of Technology, 1200 E. California Blvd., M/C 350-17, Pasadena, CA 91125 (United States)

    2014-09-01

    Using simple arguments based on photometric light curves and velocity evolution, we propose that some stripped envelope supernovae (SNe) show signs that a significant fraction of their helium is effectively transparent. The main pieces of evidence are the relatively low velocities with little velocity evolution, as are expected deep inside an exploding star, along with temperatures that are too low to ionize helium. This means that the helium should not contribute to the shaping of the main SN light curve, and thus the total helium mass may be difficult to measure from simple light curve modeling. Conversely, such modeling may be more useful for constraining the mass of the carbon/oxygen core of the SN progenitor. Other stripped envelope SNe show higher velocities and larger velocity gradients, which require an additional opacity source (perhaps the mixing of heavier elements or radioactive nickel) to prevent the helium from being transparent. We discuss ways in which similar analysis can provide insights into the differences and similarities between SNe Ib and Ic, which will lead to a better understanding of their respective formation mechanisms.

  7. SCREW COMPRESSOR CHARACTERISTICS FOR HELIUM REFRIGERATION SYSTEMS

    SciTech Connect

    Ganni, Venkatarao; Knudsen, Peter; Creel, Jonathan; Arenius, Dana; Casagrande, Fabio; Howell, Matt

    2008-03-01

    The oil injected screw compressors have practically replaced all other types of compressors in modern helium refrigeration systems due to their large displacement capacity, minimal vibration, reliability and capability of handling helium's high heat of compression.At the present state of compressor system designs for helium systems, typically two-thirds of the lost input power is due to the compression system. Therefore it is important to understand the isothermal and volumetric efficiencies of these machines to help properly design these compression systems to match the refrigeration process. This presentation summarizes separate tests that have been conducted on Sullair compressors at the Superconducting Super-Collider Laboratory (SSCL) in 1993, Howden compressors at Jefferson Lab (JLab) in 2006 and Howden compressors at the Spallation Neutron Source (SNS) in 2006. This work is part of an ongoing study at JLab to understand the theoretical basis for these efficiencies and their loss

  8. Helium damage in austenitic stainless steels

    SciTech Connect

    Caskey, G.R. Jr.; Mezzanotte, D.A. Jr.; Rawl, D.E. Jr.

    1983-01-01

    Helium produced by tritium decay was first shown to embrittle austenitic stainless steel at ambient temperature in tensile specimens of Nitronic-40 steel (Armco, Inc.). A long-term study was initiated to study this form of helium damage in five austenitic alloys. Results from this study have been analyzed by the J-integral technique and show a decrease in ductile fracture toughness with increasing He-3 concentration. Sustained-load cracking tests indicate that the stress intensity required to initiate and propagate a crack also decreases with increasing He-3 concentration. 9 figures, 3 tables.

  9. METHOD OF SINTERING URANIUM DIOXIDE

    DOEpatents

    Henderson, C.M.; Stavrolakis, J.A.

    1963-04-30

    This patent relates to a method of sintering uranium dioxide. Uranium dioxide bodies are heated to above 1200 nif- C in hydrogen, sintered in steam, and then cooled in hydrogen. (AEC)

  10. Electrobiocommodities from Carbon Dioxide: Enhancing Microbial...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Electrobiocommodities from Carbon Dioxide: Enhancing Microbial Electrosynthesis with Synthetic Electromicrobiology and System Design Electrobiocommodities from Carbon Dioxide: ...

  11. Carbon dioxide sensor

    DOEpatents

    Dutta, Prabir K. (Worthington, OH); Lee, Inhee (Columbus, OH); Akbar, Sheikh A. (Hilliard, OH)

    2011-11-15

    The present invention generally relates to carbon dioxide (CO.sub.2) sensors. In one embodiment, the present invention relates to a carbon dioxide (CO.sub.2) sensor that incorporates lithium phosphate (Li.sub.3PO.sub.4) as an electrolyte and sensing electrode comprising a combination of lithium carbonate (Li.sub.2CO.sub.3) and barium carbonate (BaCO.sub.3). In another embodiment, the present invention relates to a carbon dioxide (CO.sub.2) sensor has a reduced sensitivity to humidity due to a sensing electrode with a layered structure of lithium carbonate and barium carbonate. In still another embodiment, the present invention relates to a method of producing carbon dioxide (CO.sub.2) sensors having lithium phosphate (Li.sub.3PO.sub.4) as an electrolyte and sensing electrode comprising a combination of lithium carbonate (Li.sub.2CO.sub.3) and barium carbonate (BaCO.sub.3).

  12. THERMAL OSCILLATIONS IN LIQUID HELIUM TARGETS.

    SciTech Connect

    WANG,L.; JIA,L.X.

    2001-07-16

    A liquid helium target for the high-energy physics was built and installed in the proton beam line at the Alternate Gradient Synchrotron of Brookhaven National Laboratory in 2001. The target flask has a liquid volume of 8.25 liters and is made of thin Mylar film. A G-M/J-T cryocooler of five-watts at 4.2K was used to produce liquid helium and refrigerate the target. A thermosyphon circuit for the target was connected to the J-T circuit by a liquid/gas separator. Because of the large heat load to the target and its long transfer lines, thermal oscillations were observed during the system tests. To eliminate the oscillation, a series of tests and analyses were carried out. This paper describes the phenomena and provides the understanding of the thermal oscillations in the target system.

  13. Closed-loop pulsed helium ionization detector

    DOEpatents

    Ramsey, Roswitha S.; Todd, Richard A.

    1987-01-01

    A helium ionization detector for gas chromatography is operated in a constant current, pulse-modulated mode by configuring the detector, electrometer and a high voltage pulser in a closed-loop control system. The detector current is maintained at a fixed level by varying the frequency of fixed-width, high-voltage bias pulses applied to the detector. An output signal proportional to the pulse frequency is produced which is indicative of the charge collected for a detected species.

  14. Combined cold compressor/ejector helium refrigerator

    DOEpatents

    Brown, Donald P.

    1985-01-01

    A refrigeration apparatus having an ejector operatively connected with a cold compressor to form a two-stage pumping system. This pumping system is used to lower the pressure, and thereby the temperature of a bath of boiling refrigerant (helium). The apparatus as thus arranged and operated has substantially improved operating efficiency when compared to other processes or arrangements for achieving a similar low pressure.

  15. Combined cold compressor/ejector helium refrigerator

    DOEpatents

    Brown, D.P.

    1984-06-05

    A refrigeration apparatus having an ejector operatively connected with a cold compressor to form a two-stage pumping system. This pumping system is used to lower the pressure, and thereby the temperature of a bath of boiling refrigerant (helium). The apparatus as thus arranged and operated has substantially improved operating efficiency when compared to other processes or arrangements for achieving a similar low pressure.

  16. In situ controlled modification of the helium density in single helium-filled nanobubbles

    SciTech Connect

    David, M.-L. Pailloux, F.; Alix, K.; Mauchamp, V.; Pizzagalli, L.; Couillard, M.; Botton, G. A.

    2014-03-28

    We demonstrate that the helium density and corresponding pressure can be modified in single nano-scale bubbles embedded in semiconductors by using the electron beam of a scanning transmission electron microscope as a multifunctional probe: the measurement probe for imaging and chemical analysis and the irradiation source to modify concomitantly the pressure in a controllable way by fine tuning of the electron beam parameters. The control of the detrapping rate is achieved by varying the experimental conditions. The underlying physical mechanisms are discussed; our experimental observations suggest that the helium detrapping from bubbles could be interpreted in terms of direct ballistic collisions, leading to the ejection of the helium atoms from the bubble.

  17. Research questions reality of 'supersolid' in helium-4

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Research questions reality of 'supersolid' in helium-4 Research questions reality of 'supersolid' in helium-4 When cooled to temperatures below minus 452 degrees below zero Fahrenheit, helium-4 becomes a liquid-and an extraordinary liquid at that. May 17, 2011 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma

  18. Demonstrating Strong Electric Fields in Liquid Helium for Tests...

    Office of Science (SC)

    Demonstrating Strong Electric Fields in Liquid Helium for Tests of Matter-Antimatter Symmetry Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of ...

  19. Understanding Helium-Hydrogen Plasma Mediated Tungsten Surface...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Helium-Hydrogen Plasma Mediated Tungsten Surface Response to Predict Fusion Plasma Facing ... The realization of fusion as a practical, 21st Century energy source requires improved ...

  20. Simplified Helium Refrigerator Cycle Analysis Using the `Carnot Step'

    SciTech Connect

    P. Knudsen; V. Ganni

    2006-05-01

    An analysis of the Claude form of an idealized helium liquefier for the minimum input work reveals the ''Carnot Step'' for helium refrigerator cycles. As the ''Carnot Step'' for a multi-stage polytropic compression process consists of equal pressure ratio stages; similarly for an idealized helium liquefier the ''Carnot Step'' consists of equal temperature ratio stages for a given number of expansion stages. This paper presents the analytical basis and some useful equations for the preliminary examination of existing and new Claude helium refrigeration cycles.

  1. Lab researchers simulate helium bubble behavior in fusion reactors

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Lab researchers simulate helium bubble behavior in fusion reactors A team performed ... One of the most important challenges for successful commercialization of fusion power is ...

  2. Helium isotopes in geothermal systems- Iceland, The Geysers,...

    OpenEI (Open Energy Information) [EERE & EIA]

    isotopes in geothermal systems- Iceland, The Geysers, Raft River and Steamboat Springs Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Helium...

  3. Boron-10 Neutron Detectors for Helium-3 Replacement

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    efficiencies comparable to Helium-3 detectors, with demonstrated gamma neutron discrimination. Available for thumbnail of Feynman Center (505) 665-9090 Email Boron-10 Neutron...

  4. Process for sequestering carbon dioxide and sulfur dioxide

    DOEpatents

    Maroto-Valer, M. Mercedes (State College, PA); Zhang, Yinzhi (State College, PA); Kuchta, Matthew E. (State College, PA); Andresen, John M. (State College, PA); Fauth, Dan J. (Pittsburgh, PA)

    2009-10-20

    A process for sequestering carbon dioxide, which includes reacting a silicate based material with an acid to form a suspension, and combining the suspension with carbon dioxide to create active carbonation of the silicate-based material, and thereafter producing a metal salt, silica and regenerating the acid in the liquid phase of the suspension.

  5. Helium transport and ash control studies

    SciTech Connect

    Miley, G.H.

    1992-01-01

    The Primary goal of this research is to develop a helium (ash) transport scaling law based on experimental data from devices such as TFTR and JET. To illustrate the importance of this, we have studied ash accumulation effects on ignition requirements using a O-D transport model. Ash accumulation is characterized in the model by the ratio of the helium particle confinement time to the energy confinement time t{sub {alpha}}/t{sub E}. Results show that the ignition window'' shrinks rapidly as t{sub {alpha}}/t{sub E} increases, closing for high t{sub {alpha}}/t{sub E} increases, closing for high t{sub {alpha}}/t{sub E}. A best'' value for t{sub {alpha}}/t{sub E} will ultimately be determined from our scaling law studies. A helium transport scaling law is being sought that expresses the transport coefficients (D{sub {alpha}}, V{sub {alpha}}) as a function of the local plasma parameters. This is necessary for use in transport code calculations, e.g. for BALDUR. Based on experimental data from L-mode plasma operation in TFTR, a scaling law to a power law expression has been obtained using a least-square fit method. It is found that the transport coefficients are strongly affected by the local magnetic field and safety factor q. A preliminary conclusion from this work is that active control of ash buildup must be developed. To study control, we have developed a O-D plasma model which employs a simple pole-placement control model. Some preliminary calculations with this model are presented.

  6. Alternatives for Helium-3 in Multiplicity Counters

    SciTech Connect

    Ely, James H.; Siciliano, Edward R.; Lintereur, Azaree T.; Swinhoe, Martyn T.

    2013-04-01

    Alternatives to helium-3 are being actively pursued due to the shortage and rising costs of helium-3. For safeguards applications, there are a number of ongoing investigations to find alternatives that provide the same capability in a cost-effective manner. One of the greatest challenges is to find a comparable alternative for multiplicity counters, since they require high efficiency and short collection or die-away times. Work has been progressing on investigating three commercially available alternatives for high efficiency multiplicity counters: boron trifluoride (BF3) filled proportional tubes, boron-lined proportional tubes, and lithium fluoride with zinc sulfide coated light guides. The baseline multiplicity counter used for the investigation is the Epithermal Neutron Multiplicity Counter with 121 helium-3 filled tubes at 10 atmosphere pressure, which is a significant capability to match. The primary tool for the investigation has been modeling and simulation using the Monte Carlo N-Particle eXtended (MCNPX) radiation transport program, with experiments to validate the models. To directly calculate the coincidence rates in boron-lined (and possibly other) detectors, the MCNPX code has been enhanced to allow the existing coincidence tally to be used with energy deposition rather than neutron capture reactions. This allows boron-lined detectors to be modeled more accurately. Variations of tube number and diameter along with variations in the amount of inter-tube moderator have been conducted for the BF3 and boron-lined cases. Tube pressure was investigated for BF3, up to two atmospheres, as well as optimal boron thickness in the boron-lined tubes. The lithium fluoride was modeled as sheets of material with light guides in between, and the number and thickness of the sheets investigated. The amount of light guide, which in this case doubles as a moderator, was also optimized. The results of these modeling and simulation optimization investigations are described

  7. Helium-3 and Helium-4 acceleration by high power laser pulses for hadron therapy

    SciTech Connect

    Bulanov, S. S.; Esarey, E.; Schroeder, C. B.; Leemans, W. P.; Bulanov, S. V.; Margarone, D.; Korn, G.; Haberer, T.

    2015-06-24

    The laser driven acceleration of ions is considered a promising candidate for an ion source for hadron therapy of oncological diseases. Though proton and carbon ion sources are conventionally used for therapy, other light ions can also be utilized. Whereas carbon ions require 400 MeV per nucleon to reach the same penetration depth as 250 MeV protons, helium ions require only 250 MeV per nucleon, which is the lowest energy per nucleon among the light ions. This fact along with the larger biological damage to cancer cells achieved by helium ions, than that by protons, makes this species an interesting candidate for the laser driven ion source. Two mechanisms (Magnetic Vortex Acceleration and hole-boring Radiation Pressure Acceleration) of PW-class laser driven ion acceleration from liquid and gaseous helium targets are studied with the goal of producing 250 MeV per nucleon helium ion beams that meet the hadron therapy requirements. We show that He3 ions, having almost the same penetration depth as He4 with the same energy per nucleon, require less laser power to be accelerated to the required energy for the hadron therapy.

  8. Production of thorium-229 using helium nuclei

    DOEpatents

    Mirzadeh, Saed (Knoxville, TN) [Knoxville, TN; Garland, Marc Alan (Knoxville, TN) [Knoxville, TN

    2010-12-14

    A method for producing .sup.229Th includes the steps of providing .sup.226Ra as a target material, and bombarding the target material with alpha particles, helium-3, or neutrons to form .sup.229Th. When neutrons are used, the neutrons preferably include an epithermal neutron flux of at least 1.times.10.sup.13 n s.sup.-1cm.sup.-2. .sup.228Ra can also be bombarded with thermal and/or energetic neutrons to result in a neutron capture reaction to form .sup.229Th. Using .sup.230Th as a target material, .sup.229Th can be formed using neutron, gamma ray, proton or deuteron bombardment.

  9. Carbon dioxide and climate

    SciTech Connect

    Not Available

    1990-10-01

    Scientific and public interest in greenhouse gases, climate warming, and global change virtually exploded in 1988. The Department's focused research on atmospheric CO{sub 2} contributed sound and timely scientific information to the many questions produced by the groundswell of interest and concern. Research projects summarized in this document provided the data base that made timely responses possible, and the contributions from participating scientists are genuinely appreciated. In the past year, the core CO{sub 2} research has continued to improve the scientific knowledge needed to project future atmospheric CO{sub 2} concentrations, to estimate climate sensitivity, and to assess the responses of vegetation to rising concentrations of CO{sub 2} and to climate change. The Carbon Dioxide Research Program's goal is to develop sound scientific information for policy formulation and governmental action in response to changes of atmospheric CO{sub 2}. The Program Summary describes projects funded by the Carbon Dioxide Research Program during FY 1990 and gives a brief overview of objectives, organization, and accomplishments.

  10. Optimize carbon dioxide sequestration, enhance oil recovery

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Optimize carbon dioxide sequestration, enhance oil recovery Optimize carbon dioxide sequestration, enhance oil recovery The simulation provides an important approach to estimate ...

  11. Supercritical Carbon Dioxide / Reservoir Rock Chemical Interactions...

    OpenEI (Open Energy Information) [EERE & EIA]

    Supercritical Carbon Dioxide Reservoir Rock Chemical Interactions Jump to: navigation, search Geothermal Lab Call Projects for Supercritical Carbon Dioxide Reservoir Rock...

  12. Optimize carbon dioxide sequestration, enhance oil recovery

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Optimize carbon dioxide sequestration, enhance oil recovery Optimize carbon dioxide sequestration, enhance oil recovery The simulation provides an important approach to estimate...

  13. Case Study: Transcritical Carbon Dioxide Supermarket Refrigeration...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Transcritical Carbon Dioxide Supermarket Refrigeration Systems Case Study: Transcritical Carbon Dioxide Supermarket Refrigeration Systems This case study documents one year of ...

  14. The primordial helium abundance from updated emissivities

    SciTech Connect

    Aver, Erik; Olive, Keith A.; Skillman, Evan D.; Porter, R.L. E-mail: olive@umn.edu E-mail: skillman@astro.umn.edu

    2013-11-01

    Observations of metal-poor extragalactic H II regions allow the determination of the primordial helium abundance, Y{sub p}. The He I emissivities are the foundation of the model of the H II region's emission. Porter, Ferland, Storey, and Detisch (2012) have recently published updated He I emissivities based on improved photoionization cross-sections. We incorporate these new atomic data and update our recent Markov Chain Monte Carlo analysis of the dataset published by Izotov, Thuan, and Stasi'nska (2007). As before, cuts are made to promote quality and reliability, and only solutions which fit the data within 95% confidence level are used to determine the primordial He abundance. The previously qualifying dataset is almost entirely retained and with strong concordance between the physical parameters. Overall, an upward bias from the new emissivities leads to a decrease in Y{sub p}. In addition, we find a general trend to larger uncertainties in individual objects (due to changes in the emissivities) and an increased variance (due to additional objects included). From a regression to zero metallicity, we determine Y{sub p} = 0.2465 ± 0.0097, in good agreement with the BBN result, Y{sub p} = 0.2485 ± 0.0002, based on the Planck determination of the baryon density. In the future, a better understanding of why a large fraction of spectra are not well fit by the model will be crucial to achieving an increase in the precision of the primordial helium abundance determination.

  15. Liquid uranium alloy-helium fission reactor

    DOEpatents

    Minkov, Vladimir (Skokie, IL)

    1986-01-01

    This invention teaches a nuclear fission reactor having a core vessel and at least one tandem heat exchanger vessel coupled therewith across upper and lower passages to define a closed flow loop. Nuclear fuel such as a uranium alloy in its liquid phase fills these vessels and flow passages. Solid control elements in the reactor core vessel are adapted to be adjusted relative to one another to control fission reaction of the liquid fuel therein. Moderator elements in the other vessel and flow passages preclude fission reaction therein. An inert gas such as helium is bubbled upwardly through the heat exchanger vessel operable to move the liquid fuel upwardly therein and unidirectionally around the closed loop and downwardly through the core vessel. This helium gas is further directed to heat conversion means outside of the reactor vessels to utilize the heat from the fission reaction to generate useful output. The nuclear fuel operates in the 1200.degree.-1800.degree. C. range, and even higher to 2500.degree. C., limited only by the thermal effectiveness of the structural materials, increasing the efficiency of power generation from the normal 30-35% with 300.degree.-500.degree. C. upper limit temperature to 50-65%. Irradiation of the circulating liquid fuel, as contrasted to only localized irradiation of a solid fuel, provides improved fuel utilization.

  16. Liquid uranium alloy-helium fission reactor

    DOEpatents

    Minkov, V.

    1984-06-13

    This invention describes a nuclear fission reactor which has a core vessel and at least one tandem heat exchanger vessel coupled therewith across upper and lower passages to define a closed flow loop. Nuclear fuel such as a uranium alloy in its liquid phase fills these vessels and flow passages. Solid control elements in the reactor core vessel are adapted to be adjusted relative to one another to control fission reaction of the liquid fuel therein. Moderator elements in the other vessel and flow passages preclude fission reaction therein. An inert gas such as helium is bubbled upwardly through the heat exchanger vessel operable to move the liquid fuel upwardly therein and unidirectionally around the closed loop and downwardly through the core vessel. This helium gas is further directed to heat conversion means outside of the reactor vessels to utilize the heat from the fission reaction to generate useful output. The nuclear fuel operates in the 1200 to 1800/sup 0/C range, and even higher to 2500/sup 0/C.

  17. Double photoionization of helium with synchrotron x-rays: Proceedings

    SciTech Connect

    Not Available

    1994-01-01

    This report contains papers on the following topics: Overview and comparison of photoionization with charged particle impact; The ratio of double to single ionization of helium: the relationship of photon and bare charged particle impact ionization; Double photoionization of helium at high energies; Compton scattering of photons from electrons bound in light elements; Electron ionization and the Compton effect in double ionization of helium; Elimination of two atomic electrons by a single energy photon; Double photoionization of helium at intermediate energies; Double Photoionization: Gauge Dependence, Coulomb Explosion; Single and Double Ionization by high energy photon impact; The effect of Compton Scattering on the double to single ionization ratio in helium; and Double ionization of He by photoionization and Compton scattering. These papers have been cataloged separately for the database.

  18. Detailed and simplified nonequilibrium helium ionization in the solar atmosphere

    SciTech Connect

    Golding, Thomas Peter; Carlsson, Mats; Leenaarts, Jorrit E-mail: mats.carlsson@astro.uio.no

    2014-03-20

    Helium ionization plays an important role in the energy balance of the upper chromosphere and transition region. Helium spectral lines are also often used as diagnostics of these regions. We carry out one-dimensional radiation-hydrodynamics simulations of the solar atmosphere and find that the helium ionization is set mostly by photoionization and direct collisional ionization, counteracted by radiative recombination cascades. By introducing an additional recombination rate mimicking the recombination cascades, we construct a simplified three-level helium model atom consisting of only the ground states. This model atom is suitable for modeling nonequilibrium helium ionization in three-dimensional numerical models. We perform a brief investigation of the formation of the He I 10830 and He II 304 spectral lines. Both lines show nonequilibrium features that are not recovered with statistical equilibrium models, and caution should therefore be exercised when such models are used as a basis for interpretating observations.

  19. Uranium dioxide electrolysis

    DOEpatents

    Willit, James L.; Ackerman, John P.; Williamson, Mark A.

    2009-12-29

    This is a single stage process for treating spent nuclear fuel from light water reactors. The spent nuclear fuel, uranium oxide, UO.sub.2, is added to a solution of UCl.sub.4 dissolved in molten LiCl. A carbon anode and a metallic cathode is positioned in the molten salt bath. A power source is connected to the electrodes and a voltage greater than or equal to 1.3 volts is applied to the bath. At the anode, the carbon is oxidized to form carbon dioxide and uranium chloride. At the cathode, uranium is electroplated. The uranium chloride at the cathode reacts with more uranium oxide to continue the reaction. The process may also be used with other transuranic oxides and rare earth metal oxides.

  20. Initial assessment of environmental effects on SiC/SiC composites in helium-cooled nuclear systems

    SciTech Connect

    Contescu, Cristian I

    2013-09-01

    This report summarized the information available in the literature on the chemical reactivity of SiC/SiC composites and of their components in contact with the helium coolant used in HTGR, VHTR and GFR designs. In normal operation conditions, ultra-high purity helium will have chemically controlled impurities (water, oxygen, carbon dioxide, carbon monoxide, methane, hydrogen) that will create a slightly oxidizing gas environment. Little is known from direct experiments on the reactivity of third generation (nuclear grade) SiC/SiC composites in contact with low concentrations of water or oxygen in inert gas, at high temperature. However, there is ample information about the oxidation in dry and moist air of SiC/SiC composites at high temperatures. This information is reviewed first in the next chapters. The emphasis is places on the improvement in material oxidation, thermal, and mechanical properties during three stages of development of SiC fibers and at least two stages of development of the fiber/matrix interphase. The chemical stability of SiC/SiC composites in contact with oxygen or steam at temperatures that may develop in off-normal reactor conditions supports the conclusion that most advanced composites (also known as nuclear grade SiC/SiC composites) have the chemical resistance that would allow them maintain mechanical properties at temperatures up to 1200 1300 oC in the extreme conditions of an air or water ingress accident scenario. Further research is needed to assess the long-term stability of advanced SiC/SiC composites in inert gas (helium) in presence of very low concentrations (traces) of water and oxygen at the temperatures of normal operation of helium-cooled reactors. Another aspect that needs to be investigated is the effect of fast neutron irradiation on the oxidation stability of advanced SiC/SiC composites in normal operation conditions.

  1. Superconducting cable cooling system by helium gas and a mixture of gas and liquid helium

    DOEpatents

    Dean, John W.

    1977-01-01

    Thermally contacting, oppositely streaming cryogenic fluid streams in the same enclosure in a closed cycle that changes from a cool high pressure helium gas to a cooler reduced pressure helium fluid comprised of a mixture of gas and boiling liquid so as to be near the same temperature but at different pressures respectively in go and return legs that are in thermal contact with each other and in thermal contact with a longitudinally extending superconducting transmission line enclosed in the same cable enclosure that insulates the line from the ambient at a temperature T.sub.1. By first circulating the fluid in a go leg from a refrigerator at one end of the line as a high pressure helium gas near the normal boiling temperature of helium; then circulating the gas through an expander at the other end of the line where the gas becomes a mixture of reduced pressure gas and boiling liquid at its boiling temperature; then by circulating the mixture in a return leg that is separated from but in thermal contact with the gas in the go leg and in the same enclosure therewith; and finally returning the resulting low pressure gas to the refrigerator for compression into a high pressure gas at T.sub.2 is a closed cycle, where T.sub.1 >T.sub.2, the temperature distribution is such that the line temperature is nearly constant along its length from the refrigerator to the expander due to the boiling of the liquid in the mixture. A heat exchanger between the go and return lines removes the gas from the liquid in the return leg while cooling the go leg.

  2. Compact hydrogen/helium isotope mass spectrometer

    DOEpatents

    Funsten, Herbert O.; McComas, David J.; Scime, Earl E.

    1996-01-01

    The compact hydrogen and helium isotope mass spectrometer of the present invention combines low mass-resolution ion mass spectrometry and beam-foil interaction technology to unambiguously detect and quantify deuterium (D), tritium (T), hydrogen molecule (H.sub.2, HD, D.sub.2, HT, DT, and T.sub.2), .sup.3 He, and .sup.4 He concentrations and concentration variations. The spectrometer provides real-time, high sensitivity, and high accuracy measurements. Currently, no fieldable D or molecular speciation detectors exist. Furthermore, the present spectrometer has a significant advantage over traditional T detectors: no confusion of the measurements by other beta-emitters, and complete separation of atomic and molecular species of equivalent atomic mass (e.g., HD and .sup.3 He).

  3. Helium isotopes and tectonics in southern Italy

    SciTech Connect

    Sano, Yuji; Wakita, Hiroshi ); Nuccio, M.P. ); Italiano, F.

    1989-06-01

    Geodynamic evolution of southern Italy can be understood within the framework of the Mediterranean-Alpine System. Subduction of a plate along the Sicily-Calabrian forearc under the Tyrrhenian Sea has been suggested by many geophysicists, although it is not yet confirmed and remains somewhat controversial. Helium isotope ratios provide useful information on the geotectonic structure of the region. The authors report here the {sup 3}H/{sup 4}He ratios of terrestrial gas samples from southern Italy. The observed {sup 3}He/{sup 4}He ratios are relatively high in the Eolian volcanic arc region and low in the other areas. Dichotomous explanations are presented. Firstly, volcanic arc-forearc hypothesis suggests the subduction along the Sicily-Calabrian forearc. Secondly, horizontal transport hypothesis is described based on the relationship between the ratios and radial distance from the recent spreading basin in Southern Tyrrhenian Sea.

  4. Reducing carbon dioxide to products

    DOEpatents

    Cole, Emily Barton; Sivasankar, Narayanappa; Parajuli, Rishi; Keets, Kate A

    2014-09-30

    A method reducing carbon dioxide to one or more products may include steps (A) to (C). Step (A) may bubble said carbon dioxide into a solution of an electrolyte and a catalyst in a divided electrochemical cell. The divided electrochemical cell may include an anode in a first cell compartment and a cathode in a second cell compartment. The cathode may reduce said carbon dioxide into said products. Step (B) may adjust one or more of (a) a cathode material, (b) a surface morphology of said cathode, (c) said electrolyte, (d) a manner in which said carbon dioxide is bubbled, (e), a pH level of said solution, and (f) an electrical potential of said divided electrochemical cell, to vary at least one of (i) which of said products is produced and (ii) a faradaic yield of said products. Step (C) may separate said products from said solution.

  5. Recuperative supercritical carbon dioxide cycle

    SciTech Connect

    Sonwane, Chandrashekhar; Sprouse, Kenneth M; Subbaraman, Ganesan; O'Connor, George M; Johnson, Gregory A

    2014-11-18

    A power plant includes a closed loop, supercritical carbon dioxide system (CLS-CO.sub.2 system). The CLS-CO.sub.2 system includes a turbine-generator and a high temperature recuperator (HTR) that is arranged to receive expanded carbon dioxide from the turbine-generator. The HTR includes a plurality of heat exchangers that define respective heat exchange areas. At least two of the heat exchangers have different heat exchange areas.

  6. METHOD OF MAKING PLUTONIUM DIOXIDE

    DOEpatents

    Garner, C.S.

    1959-01-13

    A process is presented For converting both trivalent and tetravalent plutonium oxalate to substantially pure plutonium dioxide. The plutonium oxalate is carefully dried in the temperature range of 130 to300DEC by raising the temperature gnadually throughout this range. The temperature is then raised to 600 C in the period of about 0.3 of an hour and held at this level for about the same length of time to obtain the plutonium dioxide.

  7. How to make Raman-inactive helium visible in Raman spectra of tritium-helium gas mixtures

    SciTech Connect

    Schloesser, M.; Pakari, O.; Rupp, S.; Mirz, S.; Fischer, S.

    2015-03-15

    Raman spectroscopy, a powerful method for the quantitative compositional analysis of molecular gases, e.g. mixtures of hydrogen isotopologues, is not able to detect monoatomic species like helium. This deficit can be overcome by using radioluminescence emission from helium atoms induced by β-electrons from tritium decay. We present theoretical considerations and combined Raman/radioluminescence spectra. Furthermore, we discuss the linearity of the method together with validation measurements for determining the pressure dependence. Finally, we conclude how this technique can be used for samples of helium with traces of tritium, and vice versa. (authors)

  8. Helium bubble distributions in reactor tank repair specimens. Part 1

    SciTech Connect

    Tosten, M.H.; Kestin, P.A.

    1992-03-01

    This report discusses the Reactor Tank Repair (RTR) program was initiated to develop an in-tank repair process capable of repairing stress corrosion cracks within the SRS reactor tank walls, in the event that such a repair is needed. Previous attempts to repair C-reactor tank with a gas tungsten arc (GTA) welding process were unsuccessful due to significant cracking that occurred in the heat-affected-zones adjacent to the repair welds. It was determined that this additional cracking was a result of helium embrittlement caused by the combined effects of helium (existing within the tank walls), the high heat input associated with the GTA process, and weld shrinkage stresses. Based on the results of earlier studies it was suggested that the effects of helium embrittlement could be minimized by using a low heat input GMA process. Metallographic analysis played an important role throughout the investigation of alternative welding methods for the repair of helium-containing materials.

  9. Technique to eliminate helium induced weld cracking in stainless steels

    SciTech Connect

    Chin-An Wang; Chin, B.A.; Grossbeck, M.L.

    1992-12-31

    Experiments have shown that Type 316 stainless steel is susceptible to heat-affected-zone (HAZ) cracking upon cooling when welded using the gas tungsten arc (GTA) process under lateral constraint. The cracking has been hypothesized to be caused by stress-assisted helium bubble growth and rupture at grain boundaries. This study utilized an experimental welding setup which enabled different compressive stresses to be applied to the plates during welding. Autogenous GTA welds were produced in Type 316 stainless steel doped with 256 appm helium. The application of a compressive stress, 55 Mpa, during welding suppressed the previously observed catastrophic cracking. Detailed examinations conducted after welding showed a dramatic change in helium bubble morphology. Grain boundary bubble growth along directions parallel to the weld was suppressed. Results suggest that stress-modified welding techniques may be used to suppress or eliminate helium-induced cracking during joining of irradiated materials.

  10. Helium bubble distributions in reactor tank repair specimens

    SciTech Connect

    Tosten, M.H.; Kestin, P.A.

    1992-03-01

    This report discusses the Reactor Tank Repair (RTR) program was initiated to develop an in-tank repair process capable of repairing stress corrosion cracks within the SRS reactor tank walls, in the event that such a repair is needed. Previous attempts to repair C-reactor tank with a gas tungsten arc (GTA) welding process were unsuccessful due to significant cracking that occurred in the heat-affected-zones adjacent to the repair welds. It was determined that this additional cracking was a result of helium embrittlement caused by the combined effects of helium (existing within the tank walls), the high heat input associated with the GTA process, and weld shrinkage stresses. Based on the results of earlier studies it was suggested that the effects of helium embrittlement could be minimized by using a low heat input GMA process. Metallographic analysis played an important role throughout the investigation of alternative welding methods for the repair of helium-containing materials.

  11. Ab initio study of helium behavior in titanium tritides

    SciTech Connect

    Liang, J. H.; Dai, Yunya; Yang, Li; Peng, SM; Fan, K. M.; Long, XG; Zhou, X. S.; Zu, Xiaotao; Gao, Fei

    2013-03-01

    Ab initio calculations based on density functional theory have been performed to investigate the relative stability of titanium tritides and the helium behavior in stable titanium tritides. The results show that the β-phase TiT1.5 without two tritium along the [100] direction (TiT1.5[100]) is more stable than other possible structures. The stability of titanium tritides decrease with the increased generation of helium in TiT1.5[100]. In addition, helium generated by tritium decay prefers locating at a tetrahedral site, and favorably migrates between two neighbor vacant tetrahedral sites through an intermediate octahedral site in titanium tritides, with a migration energy of 0.23 eV. Furthermore, helium is easily accumulated on a (100) plane in β-phase TiT1.5[100].

  12. The Hall D solenoid helium refrigeration system at JLab

    SciTech Connect

    Laverdure, Nathaniel A.; Creel, Jonathan D.; Dixon, Kelly d.; Ganni, Venkatarao; Martin, Floyd D.; Norton, Robert O.; Radovic, Sasa

    2014-01-01

    Hall D, the new Jefferson Lab experimental facility built for the 12GeV upgrade, features a LASS 1.85 m bore solenoid magnet supported by a 4.5 K helium refrigerator system. This system consists of a CTI 2800 4.5 K refrigerator cold box, three 150 hp screw compressors, helium gas management and storage, and liquid helium and nitrogen storage for stand-alone operation. The magnet interfaces with the cryo refrigeration system through an LN2-shielded distribution box and transfer line system, both designed and fabricated by JLab. The distribution box uses a thermo siphon design to respectively cool four magnet coils and shields with liquid helium and nitrogen. We describe the salient design features of the cryo system and discuss our recent commissioning experience.

  13. Underground helium travels to the Earth's surface via aquifers...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Tweet EmailPrint Before it can put the party in party balloons, helium is carried from deep within the Earth's crust to the surface via aquifers, according to new research...

  14. Process Options for Nominal 2-K Helium Refrigeration System Designs

    SciTech Connect

    Peter Knudsen, Venkatarao Ganni

    2012-07-01

    Nominal 2-K helium refrigeration systems are frequently used for superconducting radio frequency and magnet string technologies used in accelerators. This paper examines the trade-offs and approximate performance of four basic types of processes used for the refrigeration of these technologies; direct vacuum pumping on a helium bath, direct vacuum pumping using full or partial refrigeration recovery, cold compression, and hybrid compression (i.e., a blend of cold and warm sub-atmospheric compression).

  15. Recovery of purified helium or hydrogen from gas mixtures

    DOEpatents

    Merriman, J.R.; Pashley, J.H.; Stephenson, M.J.; Dunthorn, D.I.

    1974-01-15

    A process is described for the removal of helium or hydrogen from gaseous mixtures also containing contaminants. The gaseous mixture is contacted with a liquid fluorocarbon in an absorption zone maintained at superatomspheric pressure to preferentially absorb the contaminants in the fluorocarbon. Unabsorbed gas enriched in hydrogen or helium is withdrawn from the absorption zone as product. Liquid fluorocarbon enriched in contaminants is withdrawn separately from the absorption zone. (10 claims)

  16. Helium segregation on surfaces of plasma-exposed tungsten

    DOE PAGES [OSTI]

    Maroudas, Dimitrios; Blondel, Sophie; Hu, Lin; Hammond, Karl D.; Wirth, Brian D.

    2016-01-21

    Here we report a hierarchical multi-scale modeling study of implanted helium segregation on surfaces of tungsten, considered as a plasma facing component in nuclear fusion reactors. We employ a hierarchy of atomic-scale simulations based on a reliable interatomic interaction potential, including molecular-statics simulations to understand the origin of helium surface segregation, targeted molecular-dynamics (MD) simulations of near-surface cluster reactions, and large-scale MD simulations of implanted helium evolution in plasma-exposed tungsten. We find that small, mobile He-n (1 <= n <= 7) clusters in the near-surface region are attracted to the surface due to an elastic interaction force that provides themore » thermodynamic driving force for surface segregation. Elastic interaction force induces drift fluxes of these mobile Hen clusters, which increase substantially as the migrating clusters approach the surface, facilitating helium segregation on the surface. Moreover, the clusters' drift toward the surface enables cluster reactions, most importantly trap mutation, in the near-surface region at rates much higher than in the bulk material. Moreover, these near-surface cluster dynamics have significant effects on the surface morphology, near-surface defect structures, and the amount of helium retained in the material upon plasma exposure. We integrate the findings of such atomic-scale simulations into a properly parameterized and validated spatially dependent, continuum-scale reaction-diffusion cluster dynamics model, capable of predicting implanted helium evolution, surface segregation, and its near-surface effects in tungsten. This cluster-dynamics model sets the stage for development of fully atomistically informed coarse-grained models for computationally efficient simulation predictions of helium surface segregation, as well as helium retention and surface morphological evolution, toward optimal design of plasma facing components.« less

  17. Focused helium-ion beam irradiation effects on electrical transport

    Office of Scientific and Technical Information (OSTI)

    properties of few-layer WSe2: Enabling nanoscale direct write homo-junctions (Journal Article) | SciTech Connect Journal Article: Focused helium-ion beam irradiation effects on electrical transport properties of few-layer WSe2: Enabling nanoscale direct write homo-junctions Citation Details In-Document Search Title: Focused helium-ion beam irradiation effects on electrical transport properties of few-layer WSe2: Enabling nanoscale direct write homo-junctions Atomically thin transition metal

  18. Helium Pumping Wall for a Liquid Lithium Tokamak Richard Majeski |

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Princeton Plasma Physics Lab Helium Pumping Wall for a Liquid Lithium Tokamak Richard Majeski This invention is designed to be a subsystem of a device, a tokamak with walls or plasma facing components of liquid lithium. This approach to constructing the lithium-bearing walls of the tokamak allows the wall to fulfill a necessary function -- helium pumping - for which a complex structure was formerly required. The primary novel feature of the invention is that a permeable wall is used to

  19. David Lee, Douglas Osheroff, Superfluidity, and Helium 3

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    David Lee, Douglas Osheroff, Superfluidity, and Helium 3 Resources with Additional Information David M. Lee and Douglas D. Osheroff received the 1996 Nobel Prize in Physics for 'their discovery of superfluidity in helium-3'. "In 1976, Lee shared with Richardson and Osheroff their earliest recognition for studies of superfluidity, the Simon Memorial Prize of the British Physical Society. The Buckley Prize of the American Physical Society followed for the trio in 1981. ... Douglas D. Osheroff

  20. Helium Loop Cooling Channel Hydraulic Characterization

    SciTech Connect

    Olivas, Eric Richard; Morgan, Robert Vaughn; Woloshun, Keith Albert

    2015-07-02

    New methods for generating ⁹⁹Mo are being explored in an effort to eliminate proliferation issues and provide a domestic supply of ⁹⁹mTc for medical imaging. Electron accelerating technology is used by sending an electron beam through a series of ¹⁰⁰Mo targets. During this process a large amount of heat is created, which directly affects the operating temperature set for the system. In order to maintain the required temperature range, helium gas is used to serve as a cooling agent that flows through narrow channels between the target disks. Currently we are tailoring the cooling channel entrance and exits to decrease the pressure drop through the targets. Currently all hardware has be procured and manufactured to conduct flow measurements and visualization via solid particle seeder. Pressure drop will be studied as a function of mass flow and diffuser angle. The results from these experiments will help in determining target cooling geometry and validate CFD code results.

  1. SEPARATING PROTOACTINIUM WITH MANGANESE DIOXIDE

    DOEpatents

    Seaborg, G.T.; Gofman, J.W.; Stoughton, R.W.

    1958-04-22

    The preparation of U/sup 235/ and an improved method for isolating Pa/ sup 233/ from foreign products present in neutronirradiated thorium is described. The method comprises forming a solution of neutron-irradiated thorium together with a manganous salt, then adding potassium permanganate to precipitate the manganese as manganese dioxide whereby protoactinium is carried down with the nnanganese dioxide dissolving the precipitate, adding a soluble zirconium salt, and adding phosphate ion to precipitate zirconium phosphate whereby protoactinium is then carried down with the zirconium phosphate to effect a further concentration.

  2. Method for dissolving plutonium dioxide

    DOEpatents

    Tallent, Othar K.

    1978-01-01

    The fluoride-catalyzed, non-oxidative dissolution of plutonium dioxide in HNO.sub.3 is significantly enhanced in rate by oxidizing dissolved plutonium ions. It is believed that the oxidation of dissolved plutonium releases fluoride ions from a soluble plutonium-fluoride complex for further catalytic action.

  3. Helium gas bubble trapped in liquid helium in high magnetic field

    SciTech Connect

    Bai, H. Hannahs, S. T.; Markiewicz, W. D.; Weijers, H. W.

    2014-03-31

    High magnetic field magnets are used widely in the area of the condensed matter physics, material science, chemistry, geochemistry, and biology at the National High Magnetic Field Laboratory. New high field magnets of state-of-the-art are being pursued and developed at the lab, such as the current developing 32 T, 32 mm bore fully superconducting magnet. Liquid Helium (LHe) is used as the coolant for superconducting magnets or samples tested in a high magnetic field. When the magnetic field reaches a relatively high value the boil-off helium gas bubble generated by heat losses in the cryostat can be trapped in the LHe bath in the region where BzdBz/dz is less than negative 2100 T{sup 2}/m, instead of floating up to the top of LHe. Then the magnet or sample in the trapped bubble region may lose efficient cooling. In the development of the 32 T magnet, a prototype Yttrium Barium Copper Oxide coil of 6 double pancakes with an inner diameter of 40 mm and an outer diameter of 140 mm was fabricated and tested in a resistive magnet providing a background field of 15 T. The trapped gas bubble was observed in the tests when the prototype coil was ramped up to 7.5 T at a current of 200 A. This letter reports the test results on the trapped gas bubble and the comparison with the analytical results which shows they are in a good agreement.

  4. Controlled Chemistry Helium High Temperature Materials Test Loop

    SciTech Connect

    Richard N. WRight

    2005-08-01

    A system to test aging and environmental effects in flowing helium with impurity content representative of the Next Generation Nuclear Plant (NGNP) has been designed and assembled. The system will be used to expose microstructure analysis coupons and mechanical test specimens for up to 5,000 hours in helium containing potentially oxidizing or carburizing impurities controlled to parts per million levels. Impurity levels in the flowing helium are controlled through a feedback mechanism based on gas chromatography measurements of the gas chemistry at the inlet and exit from a high temperature retort containing the test materials. Initial testing will focus on determining the nature and extent of combined aging and environmental effects on microstructure and elevated temperature mechanical properties of alloys proposed for structural applications in the NGNP, including Inconel 617 and Haynes 230.

  5. Operation of drift chambers with helium based mixtures

    SciTech Connect

    Sharma, A. ); Sauli, F. )

    1994-08-01

    Helium based gas mixtures have been investigated for lowering multiple scattering contributions to the momentum resolution for intermediate energy particles. The relevant transport parameters, namely drift velocity and diffusion have been calculated for several mixtures and compared to standard argon based mixtures. Some fast, low diffusion mixtures have been identified. The small Lorentz angle computed make them promising candidates for drift chamber operation in magnetic fields. Measurements on high accuracy drift chambers in a test beam with a helium-DME (dimethyl ether) (70-30) mixture have resulted in a spatial resolution ranging from 70[mu]m to 100[mu]m.

  6. Isotope Effects and Helium Retention Behavior in Vanadium Tritide

    SciTech Connect

    Bowman, Jr., R. C.; Attalla, A.; Craft, B. D.

    1985-04-01

    The relaxation times of the H, T, and 3He nuclei have been measured in vanadium hydride and tritide samples. Substantial isotope effects in both the phase transition temperatures and diffusion parameters have been found. When compared to hydrides, the tritide samples have lower transition temperatures and faster mobilities. The differences in the occupancies of the interstitial sites are largely responsible for these isotope effects. Most of the helium atoms generated by tritium decay remain trapped in microscopic bubbles formed with the VTx lattice. Evidence is presented for the gradual growth of the helium bubbles over periods of hundreds of days.

  7. Status of the helium afterglow injector for MAMI

    SciTech Connect

    Arianer, J.; Cohen, S.; Essabaa, S.; Frascaria, R.; Zerhouni, O.; Szeremeta, F.; Wurzinger, R.; Aulenbacher, K.

    1998-01-20

    For the parity-violation experiment at the Mami cw electron accelerator facility at the University of Mainz, we need a stable polarized electron source able to deliver a current >150 {mu}A with polarization >60%. We develop the Orsay polarized electron source SELPO as an injector for MAMI. SELPO source based on a flowing helium afterglow is now operating in a high voltage platform. The terminal will be tested completely at Orsay and is foreseen to be installed at MAMI before the end of this year. Recent results obtained with an array of capillaries to generate the helium flow and a longitudinal spin direction are described.

  8. Maskless Lithography and in situ Visualization of Conductivity of Graphene using Helium Ion Microscopy

    DOE PAGES [OSTI]

    Iberi, Vighter O.; Vlassiouk, Ivan V.; Zhang, X. -G.; Matola, Brad R.; Linn, Allison R.; Joy, David Charles; Adam Justin Rondinone

    2015-07-07

    The remarkable mechanical and electronic properties of graphene make it an ideal candidate for next generation nanoelectronics. With the recent development of commercial-level single-crystal graphene layers, the potential for manufacturing household graphene-based devices has improved, but significant challenges still remain with regards to patterning the graphene into devices. In the case of graphene supported on a substrate, traditional nanofabrication techniques such as e-beam lithography (EBL) are often used in fabricating graphene nanoribbons but the multi-step processes they require can result in contamination of the graphene with resists and solvents. In this letter, we report the utility of scanning helium ionmore » lithography for fabricating functional graphene nanoconductors that are supported directly on a silicon dioxide layer, and we measure the minimum feature size achievable due to limitations imposed by thermal fluctuations and ion scattering during the milling process. Further we demonstrate that ion beams, due to their positive charging nature, may be used to observe and test the conductivity of graphene-based nanoelectronic devices in situ.« less

  9. Maskless Lithography and in situ Visualization of Conductivity of Graphene using Helium Ion Microscopy

    SciTech Connect

    Iberi, Vighter O.; Vlassiouk, Ivan V.; Zhang, X. -G.; Matola, Brad R.; Linn, Allison R.; Joy, David Charles; Adam Justin Rondinone

    2015-07-07

    The remarkable mechanical and electronic properties of graphene make it an ideal candidate for next generation nanoelectronics. With the recent development of commercial-level single-crystal graphene layers, the potential for manufacturing household graphene-based devices has improved, but significant challenges still remain with regards to patterning the graphene into devices. In the case of graphene supported on a substrate, traditional nanofabrication techniques such as e-beam lithography (EBL) are often used in fabricating graphene nanoribbons but the multi-step processes they require can result in contamination of the graphene with resists and solvents. In this letter, we report the utility of scanning helium ion lithography for fabricating functional graphene nanoconductors that are supported directly on a silicon dioxide layer, and we measure the minimum feature size achievable due to limitations imposed by thermal fluctuations and ion scattering during the milling process. Further we demonstrate that ion beams, due to their positive charging nature, may be used to observe and test the conductivity of graphene-based nanoelectronic devices in situ.

  10. Process and installation for purification of the helium contained in a mixture of gas

    SciTech Connect

    Avon, M.F.; Markarian, G.R.

    1984-04-24

    The present invention relates to a process and an installation for purification of the helium contained in a mixture of gas, employing a pre-treatment unit to retain the impurities such as water, carbon dioxide gas and heavy organic compounds, and at least one reactor of the chromatographic type located downstream of said pre-treatment unit, said process comprising the following steps of: (a) adjusting the pressure of the mixture of gas until the working pressure of the phase of adsorption is obtained, this pressure being between 10 and 30 bars, and preferably 12 to 15 bars; (b) taking the temperature of the mixture of gas at the outlet of said pre-treatment unit until it is located in the range -15/sup 0/ C./-35/sup 0/ C., and preferably -25/sup 0/ C.; (c) and sending the mixture of gas into the reactor and passing it through an absorbent, which is constituted by a microporous charcoal whose pores are of dimensions less than or equal to 20 A.

  11. Statistical properties of inter-series mixing in helium: From integrability to chaos

    SciTech Connect

    Puttner, R; Gremaud, B.; Delande, D.; Domke, M.; Martins, M.; Schlachter, A.S.; Kaindl, G.

    2001-04-23

    The photoionization spectrum of helium near the double-ionization threshold shows structure which indicated a transition towards quantum chaos.

  12. Laser induced fluorescence spectroscopy of the Ca dimer deposited on helium and mixed helium/xenon clusters

    SciTech Connect

    Gaveau, Marc-André; Pothier, Christophe; Briant, Marc; Mestdagh, Jean-Michel

    2014-12-09

    We study how the laser induced fluorescence spectroscopy of the calcium dimer deposited on pure helium clusters is modified by the addition of xenon atoms. In the wavelength range between 365 and 385 nm, the Ca dimer is excited from its ground state up to two excited electronic states leading to its photodissociation in Ca({sup 1}P)+Ca({sup 1}S): this process is monitored by recording the Ca({sup 1}P) fluorescence at 422.7nm. One of these electronic states of Ca{sub 2} is a diexcited one correlating to the Ca(4s4p{sup 3}P(+Ca(4s3d{sup 3}D), the other one is a repulsive state correlating to the Ca(4s4p1P)+Ca(4s21S) asymptote, accounting for the dissociation of Ca{sub 2} and the observation of the subsequent Ca({sup 1}P) emission. On pure helium clusters, the fluorescence exhibits the calcium atomic resonance line Ca({sup 1}S←{sup 1}P) at 422.7 nm (23652 cm{sup −1}) assigned to ejected calcium, and a narrow red sided band corresponding to calcium that remains solvated on the helium cluster. When adding xenon atoms to the helium clusters, the intensity of these two features decreases and a new spectral band appears on the red side of calcium resonance line; the intensity and the red shift of this component increase along with the xenon quantity deposited on the helium cluster: it is assigned to the emission of Ca({sup 1}P) associated with the small xenon aggregate embedded inside the helium cluster.

  13. FY-05 First Quarter Report on Development of a Supercritical Carbon Dioxide Brayton Cycle: Improving PBR Efficiency and Testing Material Compatibility

    SciTech Connect

    Chang Oh

    2005-01-01

    The objective of this research is to improve a helium Brayton cycle and to develop a supercritical carbon dioxide Brayton cycle for the Pebble Bed Reactor (PBR) that can also be applied to the Fast Gas-Cooled Reactor (FGR) and the Very-High-Temperature Gas- Cooled Reactor (VHTR). The proposed supercritical carbon dioxide Brayton cycle will be used to improve the PBR, FGR, and VHTR net plant efficiency. Another objective of this research is to test materials to be used in the power conversion side at supercritical carbon dioxide conditions. Generally, the optimized Brayton cycle and balance of plant (BOP) to be developed from this study can be applied to Generation-IV reactor concepts. Particularly, we are interested in VHTR because it has a good chance of being built in the near future.

  14. FY-05 Second Quarter Report On Development of a Supercritical Carbon Dioxide Brayton Cycle: Improving PBR Efficiency and Testing Material Compatibility

    SciTech Connect

    Chang Oh

    2005-04-01

    The objective of this research is to improve a helium Brayton cycle and to develop a supercritical carbon dioxide Brayton cycle for the Pebble Bed Reactor (PBR) that can also be applied to the Fast Gas-Cooled Reactor (FGR) and the Very-High-Temperature Gas- Cooled Reactor (VHTR). The proposed supercritical carbon dioxide Brayton cycle will be used to improve the PBR, FGR, and VHTR net plant efficiency. Another objective of this research is to test materials to be used in the power conversion side at supercritical carbon dioxide conditions. Generally, the optimized Brayton cycle and balance of plant (BOP) to be developed from this study can be applied to Generation-IV reactor concepts. Particularly, we are interested in VHTR because it has a good chance of being built in the near future.

  15. High capacity carbon dioxide sorbent

    DOEpatents

    Dietz, Steven Dean; Alptekin, Gokhan; Jayaraman, Ambalavanan

    2015-09-01

    The present invention provides a sorbent for the removal of carbon dioxide from gas streams, comprising: a CO.sub.2 capacity of at least 9 weight percent when measured at 22.degree. C. and 1 atmosphere; an H.sub.2O capacity of at most 15 weight percent when measured at 25.degree. C. and 1 atmosphere; and an isosteric heat of adsorption of from 5 to 8.5 kilocalories per mole of CO.sub.2. The invention also provides a carbon sorbent in a powder, a granular or a pellet form for the removal of carbon dioxide from gas streams, comprising: a carbon content of at least 90 weight percent; a nitrogen content of at least 1 weight percent; an oxygen content of at most 3 weight percent; a BET surface area from 50 to 2600 m.sup.2/g; and a DFT micropore volume from 0.04 to 0.8 cc/g.

  16. Method for carbon dioxide sequestration

    DOEpatents

    Wang, Yifeng; Bryan, Charles R.; Dewers, Thomas; Heath, Jason E.

    2015-09-22

    A method for geo-sequestration of a carbon dioxide includes selection of a target water-laden geological formation with low-permeability interbeds, providing an injection well into the formation and injecting supercritical carbon dioxide (SC--CO.sub.2) into the injection well under conditions of temperature, pressure and density selected to cause the fluid to enter the formation and splinter and/or form immobilized ganglia within the formation. This process allows for the immobilization of the injected SC--CO.sub.2 for very long times. The dispersal of scCO2 into small ganglia is accomplished by alternating injection of SC--CO.sub.2 and water. The injection rate is required to be high enough to ensure the SC--CO.sub.2 at the advancing front to be broken into pieces and small enough for immobilization through viscous instability.

  17. CARBON DIOXIDE AS A FEEDSTOCK.

    SciTech Connect

    CREUTZ,C.; FUJITA,E.

    2000-12-09

    This report is an overview on the subject of carbon dioxide as a starting material for organic syntheses of potential commercial interest and the utilization of carbon dioxide as a substrate for fuel production. It draws extensively on literature sources, particularly on the report of a 1999 Workshop on the subject of catalysis in carbon dioxide utilization, but with emphasis on systems of most interest to us. Atmospheric carbon dioxide is an abundant (750 billion tons in atmosphere), but dilute source of carbon (only 0.036 % by volume), so technologies for utilization at the production source are crucial for both sequestration and utilization. Sequestration--such as pumping CO{sub 2} into sea or the earth--is beyond the scope of this report, except where it overlaps utilization, for example in converting CO{sub 2} to polymers. But sequestration dominates current thinking on short term solutions to global warming, as should be clear from reports from this and other workshops. The 3500 million tons estimated to be added to the atmosphere annually at present can be compared to the 110 million tons used to produce chemicals, chiefly urea (75 million tons), salicylic acid, cyclic carbonates and polycarbonates. Increased utilization of CO{sub 2} as a starting material is, however, highly desirable, because it is an inexpensive, non-toxic starting material. There are ongoing efforts to replace phosgene as a starting material. Creation of new materials and markets for them will increase this utilization, producing an increasingly positive, albeit small impact on global CO{sub 2} levels. The other uses of interest are utilization as a solvent and for fuel production and these will be discussed in turn.

  18. Lessons Learned From Gen I Carbon Dioxide Cooled Reactors

    SciTech Connect

    David E. Shropshire

    2004-04-01

    This paper provides a review of early gas cooled reactors including the Magnox reactors originating in the United Kingdom and the subsequent development of the Advanced Gas-cooled Reactors (AGR). These early gas cooled reactors shared a common coolant medium, namely carbon dioxide (CO2). A framework of information is provided about these early reactors and identifies unique problems/opportunities associated with use of CO2 as a coolant. Reactor designers successfully rose to these challenges. After years of successful use of the CO2 gas cooled reactors in Europe, the succeeding generation of reactors, called the High Temperature Gas Reactors (HTGR), were designed with Helium gas as the coolant. Again, in the 21st century, with the latest reactor designs under investigation in Generation IV, there is a revived interest in developing Gas Cooled Fast Reactors that use CO2 as the reactor coolant. This paper provides a historical perspective on the 52 CO2 reactors and the reactor programs that developed them. The Magnox and AGR design features and safety characteristics were reviewed, as well as the technologies associated with fuel storage, reprocessing, and disposal. Lessons-learned from these programs are noted to benefit the designs of future generations of gas cooled nuclear reactors.

  19. An investigation of thermally driven acoustical oscillations in helium systems

    SciTech Connect

    Fuerst, J.D.

    1990-08-01

    The phenomenon of thermal-acoustic oscillation is seen to arise spontaneously in gas columns subjected to steep temperature gradients, particularly in tubes connecting liquid helium reservoirs with the ambient environment. This if often the arrangement for installed cryogenic instrumentation and is accompanied by undesirably large heat transfer rates to the cold region. Experimental data are collected and matched to theoretical predictions of oscillatory behavior; these results are in good agreement with the analytical model and with previously collected data. The present experiment places the open ends of oscillating tubes of the various lengths and cross sections in communication with flowing helium in the subcooled, 2-phase, or superheated state while the other ends are maintained at some controlled, elevated temperature. Assorted cold end conditions are achieved through adjustments to the Fermilab Tevatron satellite test refrigerator to which the test cryostat is connected. The warm, closed ends of the tubes are maintained by isothermal baths of liquid nitrogen, ice water, and boiling water. The method is contrasted to previous arrangements whereby tubes are run from room temperature into or adjacent to a stagnant pool of liquid helium. Additionally, the effect of pulsations in the flowing helium stream is explored through operation of the refrigerator's wet and dry expanders during data collection. These data confirm the theory to which try were compared and support its use in the design of cryogenic sensing lines for avoidance of thermoacoustic oscillation.

  20. TRANSMISSION ELECTRON MICROSCOPY STUDY OF HELIUM BEARING FUSION WELDS

    SciTech Connect

    Tosten, M; Michael Morgan, M

    2008-12-12

    A transmission electron microscopy (TEM) study was conducted to characterize the helium bubble distributions in tritium-charged-and-aged 304L and 21Cr-6Ni-9Mn stainless steel fusion welds containing approximately 150 appm helium-3. TEM foils were prepared from C-shaped fracture toughness test specimens containing {delta} ferrite levels ranging from 4 to 33 volume percent. The weld microstructures in the low ferrite welds consisted mostly of austenite and discontinuous, skeletal {delta} ferrite. In welds with higher levels of {delta} ferrite, the ferrite was more continuous and, in some areas of the 33 volume percent sample, was the matrix/majority phase. The helium bubble microstructures observed were similar in all samples. Bubbles were found in the austenite but not in the {delta} ferrite. In the austenite, bubbles had nucleated homogeneously in the grain interiors and heterogeneously on dislocations. Bubbles were not found on any austenite/austenite grain boundaries or at the austenite/{delta} ferrite interphase interfaces. Bubbles were not observed in the {delta} ferrite because of the combined effects of the low solubility and rapid diffusion of tritium through the {delta} ferrite which limited the amount of helium present to form visible bubbles.

  1. How Atomic Vibrations Transform Vanadium Dioxide

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    How Atomic Vibrations Transform Vanadium Dioxide How Atomic Vibrations Transform Vanadium Dioxide Calculations Confirm Material's Potential for Next-Generation Electronics, Energy November 10, 2014 Contact: Dawn Levy, levyd@ornl.gov, 865.576.6448 Budaivibe Vanadium atoms (blue) have unusually large thermal vibrations that stabilize the metallic state of a vanadium dioxide crystal. Red depicts oxygen atoms. Image credit: Oak Ridge National Laboratory For more than 50 years, scientists have

  2. Optimize carbon dioxide sequestration, enhance oil recovery

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Optimize carbon dioxide sequestration, enhance oil recovery Optimize carbon dioxide sequestration, enhance oil recovery The simulation provides an important approach to estimate the potential of storing carbon dioxide in depleted oil fields while simultaneously maximizing oil production. January 8, 2014 Schematic of a water-alternating-with-gas flood for CO2 sequestration and enhanced oil recovery. Schematic of a water-alternating-with-gas flood for CO2 sequestration and enhanced oil recovery.

  3. Optimize carbon dioxide sequestration, enhance oil recovery

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Optimize carbon dioxide sequestration, enhance oil recovery Optimize carbon dioxide sequestration, enhance oil recovery The simulation provides an important approach to estimate the potential of storing carbon dioxide in depleted oil fields while simultaneously maximizing oil production. January 8, 2014 Schematic of a water-alternating-with-gas flood for CO2 sequestration and enhanced oil recovery. Schematic of a water-alternating-with-gas flood for CO2 sequestration and enhanced oil recovery.

  4. ARM - Measurement - Carbon dioxide (CO2) flux

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    carbon dioxide, a heavy, colorless greenhouse gas. Categories Atmospheric Carbon, Surface Properties Instruments The above measurement is considered scientifically relevant for the...

  5. Project Profile: Carbon Dioxide Shuttling Thermochemical Storage...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Project Profile: Carbon Dioxide Shuttling Thermochemical Storage Using Strontium Carbonate University of Florida Logo -- This project is inactive -- The University of Florida (UF), ...

  6. Method of Making Uranium Dioxide Bodies

    DOEpatents

    Wilhelm, H. A.; McClusky, J. K.

    1973-09-25

    Sintered uranium dioxide bodies having controlled density are produced from U.sub.3 O.sub.8 and carbon by varying the mole ratio of carbon to U.sub.3 O.sub.8 in the mixture, which is compressed and sintered in a neutral or slightly oxidizing atmosphere to form dense slightly hyperstoichiometric uranium dioxide bodies. If the bodies are to be used as nuclear reactor fuel, they are subsequently heated in a hydrogen atmosphere to achieve stoichiometry. This method can also be used to produce fuel elements of uranium dioxide -- plutonium dioxide having controlled density.

  7. Quantum entanglement for helium atom in the Debye plasmas

    SciTech Connect

    Lin, Yen-Chang; Fang, Te-Kuei; Ho, Yew Kam

    2015-03-15

    In the present work, we present an investigation on quantum entanglement of the two-electron helium atom immersed in weakly coupled Debye plasmas, modeled by the Debye-Hckel, or screened Coulomb, potential to mimic the interaction between two charged particles inside the plasma. Quantum entanglement is related to correlation effects in a multi-particle system. In a bipartite system, a measurement made on one of the two entangled particles affects the outcome of the other particle, even if such two particles are far apart. Employing wave functions constructed with configuration interaction B-spline basis, we have quantified von Neumann entropy and linear entropy for a series of He {sup 1,3}S{sup e} and {sup 1,3}P{sup o} states in plasma-embedded helium atom.

  8. Elastic Electron Scattering from Tritium and Helium-3

    DOE R&D Accomplishments

    Collard, H.; Hofstadter, R.; Hughes, E. B.; Johansson, A.; Yearian, M. R.; Day, R. B.; Wagner, R. T.

    1964-10-01

    The mirror nuclei of tritium and helium-3 have been studied by the method of elastic electron scattering. Absolute cross sections have been measured for incident electron energies in the range 110 - 690 MeV at scattering angles lying between 40 degrees and 135 degrees in this energy range. The data have been interpreted in a straightforward manner and form factors are given for the distributions of charge and magnetic moment in the two nuclei over a range of four-momentum transfer squared 1.0 - 8.0 F{sup -2}. Model-independent radii of the charge and magnetic moment distributions are given and an attempt is made to deduce form factors describing the spatial distribution of the protons in tritium and helium-3.

  9. Source localization of brain activity using helium-free interferometer

    SciTech Connect

    Dammers, Jürgen Chocholacs, Harald; Eich, Eberhard; Boers, Frank; Faley, Michael; Dunin-Borkowski, Rafal E.; Jon Shah, N.

    2014-05-26

    To detect extremely small magnetic fields generated by the human brain, currently all commercial magnetoencephalography (MEG) systems are equipped with low-temperature (low-T{sub c}) superconducting quantum interference device (SQUID) sensors that use liquid helium for cooling. The limited and increasingly expensive supply of helium, which has seen dramatic price increases recently, has become a real problem for such systems and the situation shows no signs of abating. MEG research in the long run is now endangered. In this study, we report a MEG source localization utilizing a single, highly sensitive SQUID cooled with liquid nitrogen only. Our findings confirm that localization of neuromagnetic activity is indeed possible using high-T{sub c} SQUIDs. We believe that our findings secure the future of this exquisitely sensitive technique and have major implications for brain research and the developments of cost-effective multi-channel, high-T{sub c} SQUID-based MEG systems.

  10. Effect of Helium Accumulation on the Spent Fuel Microstructure

    SciTech Connect

    Ferry, Cecile; Piron, Jean-Paul; Stout, Ray

    2007-07-01

    In a nuclear spent fuel repository, the aqueous rapid release of radio-activity from exposed spent fuel surfaces will depend on the pellet microstructure at the arrival time of water into the disposal container. Research performed on spent fuel evolution in a closed system has shown that the evolution of microstructure under disposal conditions should be governed by the cumulated {alpha}-decay damage and the subsequent helium behavior. The evolution of fission gas bubble characteristics under repository conditions has to be assessed. In UO{sub 2} fuels with a burnup of 47.5 GWd/t, the pressure in fission gas bubbles, including the pressure increase from {alpha}-decay helium atoms, is not expected to reach the critical bubble pressure that will cause failure, thus micro-cracking in UO{sub 2} spent fuel grains is not expected. (authors)

  11. Electrobiocommodities from Carbon Dioxide: Enhancing Microbial

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Electrosynthesis with Synthetic Electromicrobiology and System Design | Department of Energy Electrobiocommodities from Carbon Dioxide: Enhancing Microbial Electrosynthesis with Synthetic Electromicrobiology and System Design Electrobiocommodities from Carbon Dioxide: Enhancing Microbial Electrosynthesis with Synthetic Electromicrobiology and System Design Presentation by Derek Lovley, UMass Amherst, during the "Targeting High-Value Challenges" panel at the Hydrogen, Hydrocarbons,

  12. Investigation of Cellular Interactions of Nanoparticles by Helium Ion Microscopy

    SciTech Connect

    Arey, Bruce W.; Shutthanandan, V.; Xie, Yumei; Tolic, Ana; Williams, Nolann G.; Orr, Galya

    2011-06-01

    The helium ion mircroscope (HIM) probes light elements (e.g. C, N, O, P) with high contrast due to the large variation in secondary electron yield, which minimizes the necessity of specimen staining. A defining characteristic of HIM is its remarkable capability to neutralize charge by the implementation of an electron flood gun, which eliminates the need for coating non-conductive specimens for imaging at high resolution. In addition, the small convergence angle in HeIM offers a large depth of field (~5x FE-SEM), enabling tall structures to be viewed in focus within a single image. Taking advantage of these capabilities, we investigate the interactions of engineered nanoparticles (NPs) at the surface of alveolar type II epithelial cells grown at the air-liquid interface (ALI). The increasing use of nanomaterials in a wide range of commercial applications has the potential to increase human exposure to these materials, but the impact of such exposure on human health is still unclear. One of the main routs of exposure is the respiratory tract, where alveolar epithelial cells present a vulnerable target at the interface with ambient air. Since the cellular interactions of NPs govern the cellular response and ultimately determine the impact on human health, our studies will help delineating relationships between particle properties and cellular interactions and response to better evaluate NP toxicity or biocompatibility. The Rutherford backscattered ion (RBI) is a helium ions imaging mode, which backscatters helium ions from every element except hydrogen, with a backscatter yield that depends on the atomic number of the target. Energy-sensitive backscatter analysis is being developed, which when combined with RBI image information, supports elemental identification at helium ion nanometer resolution. This capability will enable distinguishing NPs from cell surface structures with nanometer resolution.

  13. Modeling Helium--Hydrogen Plasma Mediated Tungsten Surface Response to

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Predict Fusion Plasma Facing Component Performance in ITER | Argonne Leadership Computing Facility Helium--Hydrogen Plasma Mediated Tungsten Surface Response to Predict Fusion Plasma Facing Component Performance in ITER PI Name: Brian Wirth PI Email: bdwirth@utk.edu Institution: University of Tennessee Allocation Program: ALCC Allocation Hours at ALCF: 70 Million Year: 2016 Research Domain: Materials Science The purpose of this project is to develop high performance materials suitable for a

  14. Mathematical modeling of a Fermilab helium liquefier coldbox

    SciTech Connect

    Geynisman, M.G.; Walker, R.J.

    1995-12-01

    Fermilab Central Helium Liquefier (CHL) facility is operated 24 hours-a-day to supply 4.6{degrees}K for the Fermilab Tevatron superconducting proton-antiproton collider Ring and to recover warm return gases. The centerpieces of the CHL are two independent cold boxes rated at 4000 and 5400 liters/hour with LN{sub 2} precool. These coldboxes are Claude cycle and have identical heat exchangers trains, but different turbo-expanders. The Tevatron cryogenics demand for higher helium supply from CHL was the driving force to investigate an installation of an expansion engine in place of the Joule-Thompson valve. A mathematical model was developed to describe the thermo- and gas-dynamic processes for the equipment included in the helium coldbox. The model is based on a finite element approach, opposite to a global variables approach, thus providing for higher accuracy and conversion stability. Though the coefficients used in thermo- and gas-dynamic equations are unique for a given coldbox, the general approach, the equations, the methods of computations, and most of the subroutines written in FORTRAN can be readily applied to different coldboxes. The simulation results are compared against actual operating data to demonstrate applicability of the model.

  15. Multiple reheat helium Brayton cycles for sodium fast reactors

    SciTech Connect

    Haihua Zhao; Per F. Peterson

    2008-07-01

    Sodium fast reactors (SFR) traditionally adopt the steam Rankine cycle for power conversion. The resulting potential for water-sodium reaction remains a continuing concern which at least partly delays the SFR technology commercialization and is a contributor to higher capital cost. Supercritical CO2 provides an alternative, but is also capable of sustaining energetic chemical reactions with sodium. Recent development on advanced inert-gas Brayton cycles could potentially solve this compatibility issue, increase thermal efficiency, and bring down the capital cost close to light water reactors. In this paper, helium Brayton cycles with multiple reheat and intercooling states are presented for SFRs with reactor outlet temperatures in the range of 510°C to 650°C. The resulting thermal efficiencies range from 39% and 47%, which is comparable with supercritical recompression CO2 cycles (SCO2 cycle). A systematic comparison between multiple reheat helium Brayton cycle and the SCO2 cycle is given, considering compatibility issues, plant site cooling temperature effect on plant efficiency, full plant cost optimization, and other important factors. The study indicates that the multiple reheat helium cycle is the preferred choice over SCO2 cycle for sodium fast reactors.

  16. Nuclear Hydrogen and Captured Carbon Dioxide for Alternative...

    Office of Scientific and Technical Information (OSTI)

    Conference: Nuclear Hydrogen and Captured Carbon Dioxide for Alternative Liquid Fuels. Citation Details In-Document Search Title: Nuclear Hydrogen and Captured Carbon Dioxide for ...

  17. Molecular Simulation of Carbon Dioxide, Brine, and Clay Mineral...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Molecular Simulation of Carbon Dioxide, Brine, and Clay Mineral Citation Details In-Document Search Title: Molecular Simulation of Carbon Dioxide, Brine, and Clay ...

  18. Modeling the Impact of Carbon Dioxide Leakage into an Unconfined...

    Office of Scientific and Technical Information (OSTI)

    the Impact of Carbon Dioxide Leakage into an Unconfined, Oxidizing Carbonate Aquifer Citation Details In-Document Search Title: Modeling the Impact of Carbon Dioxide Leakage ...

  19. NUCLEAR HYDROGEN AND CAPTURED CARBON DIOXIDE FOR ALTERNATIVE...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: NUCLEAR HYDROGEN AND CAPTURED CARBON DIOXIDE FOR ALTERNATIVE LIQUID FUELS. Citation Details In-Document Search Title: NUCLEAR HYDROGEN AND CAPTURED CARBON DIOXIDE ...

  20. Molecular Simulation of Carbon Dioxide Brine and Clay Mineral...

    Office of Scientific and Technical Information (OSTI)

    of Carbon Dioxide Brine and Clay Mineral Interactions and Determination of Contact Angles. Citation Details In-Document Search Title: Molecular Simulation of Carbon Dioxide ...

  1. Project Profile: 10-Megawatt Supercritical Carbon Dioxide Turbine...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Project Profile: 10-Megawatt Supercritical Carbon Dioxide Turbine Project Profile: 10-Megawatt Supercritical Carbon Dioxide Turbine NREL logo -- This project is inactive -- The ...

  2. Supercritical Carbon Dioxide Turbo-Expander and Heat Exchangers...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Supercritical Carbon Dioxide Turbo-Expander and Heat Exchangers Supercritical Carbon Dioxide Turbo-Expander and Heat Exchangers This fact sheet describes a supercritical carbon ...

  3. Los Alamos probes mysteries of uranium dioxide's thermal conductivity

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Mysteries of uranium dioxide's thermal conductivity Los Alamos probes mysteries of uranium dioxide's thermal conductivity New research is showing that the thermal conductivity of ...

  4. Array of titanium dioxide nanostructures for solar energy utilization...

    Office of Scientific and Technical Information (OSTI)

    Patent: Array of titanium dioxide nanostructures for solar energy utilization Citation Details In-Document Search Title: Array of titanium dioxide nanostructures for solar energy ...

  5. Impact of Sulfur Dioxide on Lean NOx Trap Catalysts | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Sulfur Dioxide on Lean NOx Trap Catalysts Impact of Sulfur Dioxide on Lean NOx Trap Catalysts 2004 Diesel Engine Emissions Reduction (DEER) Conference Presentation: University of ...

  6. Electrochemical Membrane for Carbon Dioxide Separation and Power...

    Office of Scientific and Technical Information (OSTI)

    for Carbon Dioxide Separation and Power Generation Citation Details In-Document Search Title: Electrochemical Membrane for Carbon Dioxide Separation and Power Generation ...

  7. Helium-Based Soundwave Chiller: Trillium: A Helium-Based Sonic Chiller- Tons of Freezing with 0 GWP Refrigerants

    SciTech Connect

    2010-09-01

    BEETIT Project: Penn State is designing a freezer that substitutes the use of sound waves and environmentally benign refrigerant for synthetic refrigerants found in conventional freezers. Called a thermoacoustic chiller, the technology is based on the fact that the pressure oscillations in a sound wave result in temperature changes. Areas of higher pressure raise temperatures and areas of low pressure decrease temperatures. By carefully arranging a series of heat exchangers in a sound field, the chiller is able to isolate the hot and cold regions of the sound waves. Penn State’s chiller uses helium gas to replace synthetic refrigerants. Because helium does not burn, explode or combine with other chemicals, it is an environmentally-friendly alternative to other polluting refrigerants. Penn State is working to apply this technology on a large scale.

  8. Thermodynamic properties of uranium dioxide

    SciTech Connect

    Fink, J.K.; Chasanov, M.G.; Leibowitz, L.

    1981-04-01

    In order to provide reliable and consistent data on the thermophysical properties of reactor materials for reactor safety studies, this revision is prepared for the thermodynamic properties of the uranium dioxide portion of the fuel property section of the report Properties for LMFBR Safety Analysis. Since the original report was issued in 1976, there has been international agreement on a vapor pressure equation for the total pressure over UO/sub 2/, new methods have been suggested for the calculation of enthalpy and heat capacity, and a phase change at 2670 K has been proposed. In this report, an electronic term is used in place of the Frenkel defect term in the enthalpy and heat capacity equation and the phase transition is accepted.

  9. Electrocatalysts for carbon dioxide conversion

    DOEpatents

    Masel, Richard I; Salehi-Khojin, Amin

    2015-04-21

    Electrocatalysts for carbon dioxide conversion include at least one catalytically active element with a particle size above 0.6 nm. The electrocatalysts can also include a Helper Catalyst. The catalysts can be used to increase the rate, modify the selectivity or lower the overpotential of electrochemical conversion of CO.sub.2. Chemical processes and devices using the catalysts also include processes to produce CO, HCO.sup.-, H.sub.2CO, (HCO.sub.2).sup.-, H.sub.2CO.sub.2, CH.sub.3OH, CH.sub.4, C.sub.2H.sub.4, CH.sub.3CH.sub.2OH, CH.sub.3COO.sup.-, CH.sub.3COOH, C.sub.2H.sub.6, (COOH).sub.2, or (COO.sup.-).sub.2, and a specific device, namely, a CO.sub.2 sensor.

  10. Helium-cooled solid breeder blanket design for a tokamak fusion reactor

    SciTech Connect

    Huggenberger, M.; Schultz, K.R.

    1983-11-01

    A preliminary design for a helium-cooled solid breeder blanket for a tokamak fusion reactor has been developed, and its performance looks quite good. The design is capable of bearing a 4 MW/m/sup 2/ neutron wall load, and the ideal pumping power required for the whole primary helium loop including the steam generators is only 2.5% of the total thermal power. The maximum blanket thickness including the helium duct work is only 860 mm, the minimum thickness is only 730 mm. The design work was focused on the thermalhydraulic aspects, which represent the key problems associated with using helium as a coolant. The present work demonstrates that the potential disadvantages helium has, due to its limited heat transfer capabilities, can be avoided or minimized by an appropriate thermal-hydraulic design. As a result, helium with its many advantages remains a promising fusion blanket coolant.

  11. Asteroseismic estimate of helium abundance of a solar analog binary system

    SciTech Connect

    Verma, Kuldeep; Antia, H. M.; Faria, Joo P.; Monteiro, Mrio J. P. F. G.; Basu, Sarbani; Mazumdar, Anwesh; Appourchaux, Thierry; Chaplin, William J.; Garca, Rafael A.

    2014-08-01

    16 Cyg A and B are among the brightest stars observed by Kepler. What makes these stars more interesting is that they are solar analogs. 16 Cyg A and B exhibit solar-like oscillations. In this work we use oscillation frequencies obtained using 2.5 yr of Kepler data to determine the current helium abundance of these stars. For this we use the fact that the helium ionization zone leaves a signature on the oscillation frequencies and that this signature can be calibrated to determine the helium abundance of that layer. By calibrating the signature of the helium ionization zone against models of known helium abundance, the helium abundance in the envelope of 16 Cyg A is found to lie in the range of 0.231 to 0.251 and that of 16 Cyg B lies in the range of 0.218 to 0.266.

  12. Production of carbon monoxide-free hydrogen and helium from a high-purity source

    DOEpatents

    Golden, Timothy Christopher; Farris, Thomas Stephen

    2008-11-18

    The invention provides vacuum swing adsorption processes that produce an essentially carbon monoxide-free hydrogen or helium gas stream from, respectively, a high-purity (e.g., pipeline grade) hydrogen or helium gas stream using one or two adsorber beds. By using physical adsorbents with high heats of nitrogen adsorption, intermediate heats of carbon monoxide adsorption, and low heats of hydrogen and helium adsorption, and by using vacuum purging and high feed stream pressures (e.g., pressures of as high as around 1,000 bar), pipeline grade hydrogen or helium can purified to produce essentially carbon monoxide -free hydrogen and helium, or carbon monoxide, nitrogen, and methane-free hydrogen and helium.

  13. EIA - Greenhouse Gas Emissions - Carbon Dioxide Emissions

    Gasoline and Diesel Fuel Update

    2. Carbon Dioxide Emissions 2.1. Total carbon dioxide emissions Annual U.S. carbon dioxide emissions fell by 419 million metric tons in 2009 (7.1 percent), to 5,447 million metric tons (Figure 9 and Table 6). The annual decrease-the largest over the 19-year period beginning with the 1990 baseline-puts 2009 emissions 608 million metric tons below the 2005 level, which is the Obama Administration's benchmark year for its goal of reducing U.S. emissions by 17 percent by 2020. The key factors

  14. Interim Report on the Optimization and Feasibility Studies for the Neutron Detection without Helium-3 Project

    SciTech Connect

    Ely, James H.

    2012-03-19

    This report provides the status and results of the first year's effort in modeling and simulation to investigate alternatives to helium-3 for neutron detection in safeguards applications.

  15. Theory of Positron Annihilation in Helium-Filled Bubbles in Plutonium...

    Office of Scientific and Technical Information (OSTI)

    Theory of Positron Annihilation in Helium-Filled Bubbles in Plutonium Citation Details ... This method is capable of treating system cell sizes of several thousand atoms, allowing ...

  16. Onboard Hydrogen/Helium Sensors in Support of the Global Technical...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Onboard HydrogenHelium Sensors in Support of the Global Technical Regulation: An Assessment of Performance in Fuel Cell Electric Vehicle Crash Tests Matthew B. Post, Robert ...

  17. Ultra high vacuum pumping system and high sensitivity helium leak detector

    DOEpatents

    Myneni, Ganapati Rao

    1997-01-01

    An improved helium leak detection method and apparatus are disclosed which increase the leak detection sensitivity to 10.sup.-13 atm cc s.sup.-1. The leak detection sensitivity is improved over conventional leak detectors by completely eliminating the use of o-rings, equipping the system with oil-free pumping systems, and by introducing measured flows of nitrogen at the entrances of both the turbo pump and backing pump to keep the system free of helium background. The addition of dry nitrogen flows to the system reduces backstreaming of atmospheric helium through the pumping system as a result of the limited compression ratios of the pumps for helium.

  18. Ultra high vacuum pumping system and high sensitivity helium leak detector

    DOEpatents

    Myneni, G.R.

    1997-12-30

    An improved helium leak detection method and apparatus are disclosed which increase the leak detection sensitivity to 10{sup {minus}13} atm cc/s. The leak detection sensitivity is improved over conventional leak detectors by completely eliminating the use of o-rings, equipping the system with oil-free pumping systems, and by introducing measured flows of nitrogen at the entrances of both the turbo pump and backing pump to keep the system free of helium background. The addition of dry nitrogen flows to the system reduces back streaming of atmospheric helium through the pumping system as a result of the limited compression ratios of the pumps for helium. 2 figs.

  19. Energy-related applications of helium: a revision of the ERDA-13 data base

    SciTech Connect

    Hammel, E.F.; Krupka, M.C.

    1980-08-01

    A re-examination, revision, and re-evaluation of the data base contained within the 1975 document, ERDA-13, The Energy-Related Applications of Helium, were completed and results are presented in this report. New technical and resource data, current legislative proposals, updated supply-and-demand relationships, latest legal developments, programmatic changes affectng the future demand for helium, socio-economic aspects, and the effects of the latest energy-consumption projections were considered and are discussed. In contrast to ERDA-13, however, explicit recommendations with respect to the formulation of Federal helium policy, as it pertains to the energy-related applications of helium, are not given.

  20. Helium measurements of pore-fluids obtained from SAFOD drillcore

    SciTech Connect

    Ali, S.; Stute, M.; Torgersen, T.; Winckler, G.; Kennedy, B.M.

    2010-04-15

    {sup 4}He accumulated in fluids is a well established geochemical tracer used to study crustal fluid dynamics. Direct fluid samples are not always collectable; therefore, a method to extract rare gases from matrix fluids of whole rocks by diffusion has been adapted. Helium was measured on matrix fluids extracted from sandstones and mudstones recovered during the San Andreas Fault Observatory at Depth (SAFOD) drilling in California, USA. Samples were typically collected as subcores or from drillcore fragments. Helium concentration and isotope ratios were measured 4-6 times on each sample, and indicate a bulk {sup 4}He diffusion coefficient of 3.5 {+-} 1.3 x 10{sup -8} cm{sup 2}s{sup -1} at 21 C, compared to previously published diffusion coefficients of 1.2 x 10{sup -18} cm{sup 2}s{sup -1} (21 C) to 3.0 x 10{sup -15} cm{sup 2}s{sup -1} (150 C) in the sands and clays. Correcting the diffusion coefficient of {sup 4}He{sub water} for matrix porosity ({approx}3%) and tortuosity ({approx}6-13) produces effective diffusion coefficients of 1 x 10{sup -8} cm{sup 2}s{sup -1} (21 C) and 1 x 10{sup -7} (120 C), effectively isolating pore fluid {sup 4}He from the {sup 4}He contained in the rock matrix. Model calculations indicate that <6% of helium initially dissolved in pore fluids was lost during the sampling process. Complete and quantitative extraction of the pore fluids provide minimum in situ porosity values for sandstones 2.8 {+-} 0.4% (SD, n=4) and mudstones 3.1 {+-} 0.8% (SD, n=4).

  1. Carbon dioxide-soluble polymers and swellable polymers for carbon dioxide applications

    DOEpatents

    DeSimone, Joseph M.; Birnbaum, Eva; Carbonell, Ruben G.; Crette, Stephanie; McClain, James B.; McCleskey, T. Mark; Powell, Kimberly R.; Romack, Timothy J.; Tumas, William

    2004-06-08

    A method for carrying out a catalysis reaction in carbon dioxide comprising contacting a fluid mixture with a catalyst bound to a polymer, the fluid mixture comprising at least one reactant and carbon dioxide, wherein the reactant interacts with the catalyst to form a reaction product. A composition of matter comprises carbon dioxide and a polymer and a reactant present in the carbon dioxide. The polymer has bound thereto a catalyst at a plurality of chains along the length of the polymer, and wherein the reactant interacts with the catalyst to form a reaction product.

  2. Carbon Dioxide Emission Factors for Coal

    Reports and Publications

    1994-01-01

    The Energy Information Administration (EIA) has developed factors for estimating the amount of carbon dioxide emitted, accounting for differences among coals, to reflect the changing "mix" of coal in U.S. coal consumption.

  3. Cathode fall measurement in a dielectric barrier discharge in helium

    SciTech Connect

    Hao, Yanpeng; Zheng, Bin; Liu, Yaoge

    2013-11-15

    A method based on the “zero-length voltage” extrapolation is proposed to measure cathode fall in a dielectric barrier discharge. Starting, stable, and discharge-maintaining voltages were measured to obtain the extrapolation zero-length voltage. Under our experimental conditions, the “zero-length voltage” gave a cathode fall of about 185 V. Based on the known thickness of the cathode fall region, the spatial distribution of the electric field strength in dielectric barrier discharge in atmospheric helium is determined. The strong cathode fall with a maximum field value of approximately 9.25 kV/cm was typical for the glow mode of the discharge.

  4. Dual-frequency glow discharges in atmospheric helium

    SciTech Connect

    Huang, Xiaojiang; Guo, Ying; Dai, Lu; Zhang, Jing; Shi, J. J.

    2015-10-15

    In this paper, the dual-frequency (DF) glow discharges in atmospheric helium were experimented by electrical and optical measurements in terms of current voltage characteristics and optical emission intensity. It is shown that the waveforms of applied voltages or discharge currents are the results of low frequency (LF) waveforms added to high frequency (HF) waveforms. The HF mainly influences discharge currents, and the LF mainly influences applied voltages. The gas temperatures of DF discharges are mainly affected by HF power rather than LF power.

  5. Helium nano-bubble evolution in aging metal tritides.

    SciTech Connect

    Cowgill, Donald F.

    2004-05-01

    A continuum-scale, evolutionary model of helium (He) nano-bubble nucleation, growth and He release for aging bulk metal tritides is presented which accounts for major features of the experimental database. Bubble nucleation, modeled as self-trapping of interstitially diffusing He atoms, is found to occur during the first few days following tritium introduction into the metal and is sensitive to the He diffusivity and pairing energy. An effective helium diffusivity of 0.3 x 10{sup -16} cm{sup 2}/s at 300 K is required to generate the average bubble density of 5x 1017 bubbles/cm3 observed by transmission electron microscopy (TEM). Early bubble growth by dislocation loop punching with a l/radius bubble pressure dependence produces good agreement with He atomic volumes and bubble pressures determined from swelling data, nuclear magnetic resonance (NMR) measurements, and hydride pressure-composition-temperature (PCT) shifts. The model predicts that later in life neighboring bubble interactions may first lower the loop punching pressure through cooperative stress effects, then raise the pressure by partial blocking of loops. It also accounts for the shape of the bubble spacing distribution obtained from NMR data. This distribution is found to remain fixed with age, justifying the separation of nucleation and growth phases, providing a sensitive test of the growth formulation, and indicating that further significant bubble nucleation does not occur throughout life. Helium generated within the escape depth of surfaces and surface-connected porosity produces the low-level early helium release. Accelerated or rapid release is modeled as inter-bubble fracture using an average ligament stress criterion. Good agreement is found between the predicted onset of fracture and the observed He-metal ratio (HeM) for rapid He release from bulk palladium tritide. An examination of how inter-bubble fracture varies over the bubble spacing distribution shows that the critical Hem will be

  6. Active helium target: Neutron scalar polarizability extraction via Compton scattering

    SciTech Connect

    Morris, Meg Hornidge, David; Annand, John; Strandberg, Bruno

    2015-12-31

    Precise measurement of the neutron scalar polarizabilities has been a lasting challenge because of the lack of a free-neutron target. Led by the University of Glasgow and the Mount Allison University groups of the A2 collaboration in Mainz, Germany, preparations have begun to test a recent theoretical model with an active helium target with the hope of determining these elusive quantities with small statistical, systematic, and model-dependent errors. Apparatus testing and background-event simulations have been carried out, with the full experiment projected to run in 2015. Once determined, these values can be applied to help understand quantum chromodynamics in the nonperturbative region.

  7. ARM - Measurement - Carbon dioxide (CO2) concentration

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    concentration ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Carbon dioxide (CO2) concentration The amount of carbon dioxide, a heavy, colorless greenhouse gas, per unit of volume. Categories Atmospheric Carbon Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all

  8. Copper mercaptides as sulfur dioxide indicators

    DOEpatents

    Eller, Phillip G.; Kubas, Gregory J.

    1979-01-01

    Organophosphine copper(I) mercaptide complexes are useful as convenient and semiquantitative visual sulfur dioxide gas indicators. The air-stable complexes form 1:1 adducts in the presence of low concentrations of sulfur dioxide gas, with an associated color change from nearly colorless to yellow-orange. The mercaptides are made by mixing stoichiometric amounts of the appropriate copper(I) mercaptide and phosphine in an inert organic solvent.

  9. Thorium dioxide: properties and nuclear applications

    SciTech Connect

    Belle, J.; Berman, R.M.

    1984-01-01

    This is the sixth book on reactor materials published under sponsorship of the Naval Reactors Office of the United States Department of Energy, formerly the United States Atomic Energy Commission. This book presents a comprehensive compilation of the most significant properties of thorium dioxide, much like the book Uranium Dioxide: Properties and Nuclear Applications presented information on the fuel material used in the Shippingport Pressurized Water Reactor core.

  10. Beneficial Use of Carbon Dioxide in Precast Concrete Production (Technical

    Office of Scientific and Technical Information (OSTI)

    Report) | SciTech Connect Beneficial Use of Carbon Dioxide in Precast Concrete Production Citation Details In-Document Search Title: Beneficial Use of Carbon Dioxide in Precast Concrete Production The feasibility of using carbon dioxide as feedstock in precast concrete production is studied. Carbon dioxide reacts with calcium compounds in concrete, producing solid calcium carbonates in binding matrix. Two typical precast products are examined for their capacity to store carbon dioxide during

  11. Development of a Supercritical Carbon Dioxide Brayton Cycle: Improving VHTR Efficiency and Testing Material Compatibility - Final Report

    SciTech Connect

    Chang H. Oh

    2006-06-01

    Generation IV reactors will need to be intrinsically safe, having a proliferation-resistant fuel cycle and several advantages relative to existing light water reactor (LWR). They, however, must still overcome certain technical issues and the cost barrier before it can be built in the U.S. The establishment of a nuclear power cost goal of 3.3 cents/kWh is desirable in order to compete with fossil combined-cycle, gas turbine power generation. This goal requires approximately a 30 percent reduction in power cost for stateof-the-art nuclear plants. It has been demonstrated that this large cost differential can be overcome only by technology improvements that lead to a combination of better efficiency and more compatible reactor materials. The objectives of this research are (1) to develop a supercritical carbon dioxide Brayton cycle in the secondary power conversion side that can be applied to the Very-High-Temperature Gas-Cooled Reactor (VHTR), (2) to improve the plant net efficiency by using the carbon dioxide Brayton cycle, and (3) to test material compatibility at high temperatures and pressures. The reduced volumetric flow rate of carbon dioxide due to higher density compared to helium will reduce compression work, which eventually increase plant net efficiency.

  12. Gettering of hydrogen and methane from a helium gas mixture

    SciTech Connect

    Crdenas, Rosa Elia; Stewart, Kenneth D.; Cowgill, Donald F.

    2014-11-01

    In this study, the authors developed an approach for accurately quantifying the helium content in a gas mixture also containing hydrogen and methane using commercially available getters. The authors performed a systematic study to examine how both H{sub 2} and CH{sub 4} can be removed simultaneously from the mixture using two SAES St 172{sup } getters operating at different temperatures. The remaining He within the gas mixture can then be measured directly using a capacitance manometer. The optimum combination involved operating one getter at 650?C to decompose the methane, and the second at 110?C to remove the hydrogen. This approach eliminated the need to reactivate the getters between measurements, thereby enabling multiple measurements to be made within a short time interval, with accuracy better than 1%. The authors anticipate that such an approach will be particularly useful for quantifying the He-3 in mixtures that include tritium, tritiated methane, and helium-3. The presence of tritiated methane, generated by tritium activity, often complicates such measurements.

  13. Gettering of Hydrogen and Methane from a Helium Gas Mixture

    DOE PAGES [OSTI]

    Cardenas, Rosa E.; Stewart, Kenneth D.; Cowgill, Donald F.

    2014-10-21

    In our study, the authors developed an approach for accurately quantifying the helium content in a gas mixture also containing hydrogen and methane using commercially available getters. The authors performed a systematic study to examine how both H2 and CH4 can be removed simultaneously from the mixture using two SAES St 172® getters operating at different temperatures. The remaining He within the gas mixture can then be measured directly using a capacitance manometer. Moreover, the optimum combination involved operating one getter at 650°C to decompose the methane, and the second at 110°C to remove the hydrogen. Finally, this approach eliminatedmore » the need to reactivate the getters between measurements, thereby enabling multiple measurements to be made within a short time interval, with accuracy better than 1%. The authors anticipate that such an approach will be particularly useful for quantifying the He-3 in mixtures that include tritium, tritiated methane, and helium-3. The presence of tritiated methane, generated by tritium activity, often complicates such measurements.« less

  14. Gettering of Hydrogen and Methane from a Helium Gas Mixture

    SciTech Connect

    Cardenas, Rosa E.; Stewart, Kenneth D.; Cowgill, Donald F.

    2014-10-21

    In our study, the authors developed an approach for accurately quantifying the helium content in a gas mixture also containing hydrogen and methane using commercially available getters. The authors performed a systematic study to examine how both H2 and CH4 can be removed simultaneously from the mixture using two SAES St 172® getters operating at different temperatures. The remaining He within the gas mixture can then be measured directly using a capacitance manometer. Moreover, the optimum combination involved operating one getter at 650°C to decompose the methane, and the second at 110°C to remove the hydrogen. Finally, this approach eliminated the need to reactivate the getters between measurements, thereby enabling multiple measurements to be made within a short time interval, with accuracy better than 1%. The authors anticipate that such an approach will be particularly useful for quantifying the He-3 in mixtures that include tritium, tritiated methane, and helium-3. The presence of tritiated methane, generated by tritium activity, often complicates such measurements.

  15. Ignition and extinction phenomena in helium micro hollow cathode discharges

    SciTech Connect

    Kulsreshath, M. K.; Schwaederle, L.; Dufour, T.; Lefaucheux, P.; Dussart, R.; Overzet, L. J.

    2013-12-28

    Micro hollow cathode discharges (MHCD) were produced using 250??m thick dielectric layer of alumina sandwiched between two nickel electrodes of 8??m thickness. A through cavity at the center of the chip was formed by laser drilling technique. MHCD with a diameter of few hundreds of micrometers allowed us to generate direct current discharges in helium at up to atmospheric pressure. A slowly varying ramped voltage generator was used to study the ignition and the extinction periods of the microdischarges. The analysis was performed by using electrical characterisation of the V-I behaviour and the measurement of He*({sup 3}S{sub 1}) metastable atoms density by tunable diode laser spectroscopy. At the ignition of the microdischarges, 2??s long current peak as high as 24?mA was observed, sometimes followed by low amplitude damped oscillations. At helium pressure above 400?Torr, an oscillatory behaviour of the discharge current was observed just before the extinction of the microdischarges. The same type of instability in the extinction period at high pressure also appeared on the density of He*({sup 3}S{sub 1}) metastable atoms, but delayed by a few ?s relative to the current oscillations. Metastable atoms thus cannot be at the origin of the generation of the observed instabilities.

  16. Partial cross sections of helium satellites at medium photon energies

    SciTech Connect

    Wehlitz, R.; Sellin, I.A.; Hemmers, O.

    1997-04-01

    Still of current interest is the important role of single ionization with excitation compared to single ionization alone. The coupling between the electrons and the incoming photon is a single-particle operator. Thus, an excitation in addition to an ionization, leading to a so-called satellite line in a photoelectron spectrum, is entirely due to electron-electron interaction and probes the electron correlation in the ground and final state. Therefore the authors have undertaken the study of the intensity of helium satellites He{sup +}nl (n = 2 - 6) relative to the main photoline (n = 1) as a function of photon energy at photon energies well above threshold up to 900 eV. From these results they could calculate the partial cross-sections of the helium satellites. In order to test the consistency of their satellite-to-1s ratios with published double-to-single photoionization ratios, the authors calculated the double-to-single photoionization ratio from their measured ratios using the theoretical energy-distribution curves of Chang and Poe and Le Rouzo and Dal Cappello which proved to be valid for photon energies below 120 eV. These calculated double-to-single ionization ratios agree fairly well with recent ion measurements. In the lower photon energy range the authors ratios agree better with the ratios of Doerner et al. while for higher photon energies the agreement is better with the values of Levin et al.

  17. Helium Nano-Bubble Evolution in Aging Metal Tritides

    SciTech Connect

    Cowgill, Donald F.

    2005-07-15

    A continuum-scale, evolutionary model of bubble nucleation, growth and He release for aging metal tritides is described which accounts for major features of the tritide database. Bubble nucleation, modeled as self-trapping of interstitially diffusing He atoms, occurs during the first few days following tritium introduction into the metal. Bubble growth by dislocation loop punching yields good agreement between He atomic volumes and bubble pressures determined from bulk swelling and {sup 3}He NMR data. The bubble spacing distribution determined from NMR is shown to remain fixed with age, justifying the separation of nucleation and growth phases and providing a sensitive test of the growth formulation. Late in life, bubble interactions are proposed to produce cooperative stress effects, which lower the bubble pressure. Helium generated near surfaces and surface-connected porosity accounts for the low-level early helium release. Use of an average ligament stress criterion predicts an onset of inter-bubble fracture in good agreement with the He/Metal ratio observed for rapid He release. From the model, it is concluded that He retention can be controlled through control of bubble nucleation.

  18. Mass spectrometric helium analysis of solid and gas samples from cold-fusion type experiments

    SciTech Connect

    Oliver, B.M.

    1995-12-01

    A custom mass spectrometer system, operating in static mode, has been used to measure helium in both solid and gas samples front cold-fusion type experiments. The mass spectrometer is a 2-in. Radius, 60{degrees}, permanent angle magnet instrument with a single electron-multiplier collecting. Depending on the absolute levels of helium expected, the analysis are conducted by isotope dilution or by measuring absolute collector values. Solid samples are vaporized to ensure complete helium release. Prior to analysis, the fraction of sample gas to be analyzed is exposed to a series of physical and chemical getters, including room temperature Zr-Al alloy (SAES type 101) and liquid-nitrogen cooled activated charcoal. This is done to remove active gases and hydrogen isotopes which could interfere with the helium determinations. Generally, the analysis protocol is to analyze an equal or greater number of {open_quotes}controls{close_quotes} along with the samples to accurately characterize system background and reproducibility. Absolute sensitivity for the system is approximately 1 x 10{sup 9} atoms. Absolute accuracy is 1% or better for helium levels > 10{sup 11} atoms. With few exceptions, helium analysis of solid samples front cold fusion type experiments have yielded no excess helium above usual system background. A few samples have shown helium levels in the low 10{sup 9} atom range, and some gas samples have shown {sup 4}He levels up to several hundred ppm.

  19. Effect of dynamically charged helium on tensile properties of V-4Cr-4Ti

    SciTech Connect

    Chung, H.M.; Loomis, B.A.; Nowicki, L.; Smith, D.L.

    1995-04-01

    The objective of this work is to determine the effect of displacement damage and dynamically charged helium on tensile properties of V-4Cr-4Ti alloy irradiated to 18-31 dpa at 425-600{degree}C in the Dynamic Helium Charging Experiment (DHCE).

  20. Fundamental and applied studies of helium ingrowth and aging in plutonium

    SciTech Connect

    Stevens, M.F.; Zocco, T.; Albers, R.; Becker, J.D.; Walter, K.; Cort, B.; Paisley, D.; Nastasi, M.

    1998-12-31

    This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The purpose of this project was to develop new capabilities to assess the nucleation and growth of helium-associated defects in aged plutonium metal. This effort involved both fundamental and applied models to assist in predicting the transport and kinetics of helium in the metal lattice as well as ab initio calculations of the disposition of gallium in the fcc plutonium lattice and its resulting effects on phase stability. Experimentally this project aimed to establish experimental capabilities crucial to the prediction of helium effects in metals, such as transmission electron microscopy, thermal helium effusion, and the development of a laser-driven mini-flyer for understanding the role of helium and associated defects on shock response of plutonium surrogates.

  1. Carbon dioxide capture process with regenerable sorbents

    DOEpatents

    Pennline, Henry W.; Hoffman, James S.

    2002-05-14

    A process to remove carbon dioxide from a gas stream using a cross-flow, or a moving-bed reactor. In the reactor the gas contacts an active material that is an alkali-metal compound, such as an alkali-metal carbonate, alkali-metal oxide, or alkali-metal hydroxide; or in the alternative, an alkaline-earth metal compound, such as an alkaline-earth metal carbonate, alkaline-earth metal oxide, or alkaline-earth metal hydroxide. The active material can be used by itself or supported on a substrate of carbon, alumina, silica, titania or aluminosilicate. When the active material is an alkali-metal compound, the carbon-dioxide reacts with the metal compound to generate bicarbonate. When the active material is an alkaline-earth metal, the carbon dioxide reacts with the metal compound to generate carbonate. Spent sorbent containing the bicarbonate or carbonate is moved to a second reactor where it is heated or treated with a reducing agent such as, natural gas, methane, carbon monoxide hydrogen, or a synthesis gas comprising of a combination of carbon monoxide and hydrogen. The heat or reducing agent releases carbon dioxide gas and regenerates the active material for use as the sorbent material in the first reactor. New sorbent may be added to the regenerated sorbent prior to subsequent passes in the carbon dioxide removal reactor.

  2. SEQUESTERING CARBON DIOXIDE IN COALBEDS

    SciTech Connect

    K.A.M. Gasem; R.L. Robinson, Jr.; J.E. Fitzgerald; Z. Pan; M. Sudibandriyo

    2003-04-30

    The authors' long-term goal is to develop accurate prediction methods for describing the adsorption behavior of gas mixtures on solid adsorbents over complete ranges of temperature, pressure, and adsorbent types. The originally-stated, major objectives of the current project are to: (1) measure the adsorption behavior of pure CO{sub 2}, methane, nitrogen, and their binary and ternary mixtures on several selected coals having different properties at temperatures and pressures applicable to the particular coals being studied, (2) generalize the adsorption results in terms of appropriate properties of the coals to facilitate estimation of adsorption behavior for coals other than those studied experimentally, (3) delineate the sensitivity of the competitive adsorption of CO{sub 2}, methane, and nitrogen to the specific characteristics of the coal on which they are adsorbed; establish the major differences (if any) in the nature of this competitive adsorption on different coals, and (4) test and/or develop theoretically-based mathematical models to represent accurately the adsorption behavior of mixtures of the type for which measurements are made. As this project developed, an important additional objective was added to the above original list. Namely, we were encouraged to interact with industry and/or governmental agencies to utilize our expertise to advance the state of the art in coalbed adsorption science and technology. As a result of this additional objective, we participated with the Department of Energy and industry in the measurement and analysis of adsorption behavior as part of two distinct investigations. These include (a) Advanced Resources International (ARI) DOE Project DE-FC26-00NT40924, ''Adsorption of Pure Methane, Nitrogen, and Carbon Dioxide and Their Mixtures on Wet Tiffany Coal'', and (b) the DOE-NETL Project, ''Round Robin: CO{sub 2} Adsorption on Selected Coals''. These activities, contributing directly to the DOE projects listed above, also

  3. Friction-Induced Fluid Heating in Nanoscale Helium Flows

    SciTech Connect

    Li Zhigang [Department of Mechanical Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)

    2010-05-21

    We investigate the mechanism of friction-induced fluid heating in nanoconfinements. Molecular dynamics simulations are used to study the temperature variations of liquid helium in nanoscale Poiseuille flows. It is found that the fluid heating is dominated by different sources of friction as the external driving force is changed. For small external force, the fluid heating is mainly caused by the internal viscous friction in the fluid. When the external force is large and causes fluid slip at the surfaces of channel walls, the friction at the fluid-solid interface dominates over the internal friction in the fluid and is the major contribution to fluid heating. An asymmetric temperature gradient in the fluid is developed in the case of nonidentical walls and the general temperature gradient may change sign as the dominant heating factor changes from internal to interfacial friction with increasing external force.

  4. Electron impact excitation of helium in Debye plasma

    SciTech Connect

    Diallo, S.; Gomis, L.; Faye, I. G.; Tall, M. S.; Diédhiou, I.; Diatta, C. S.; Zammit, M.

    2015-03-15

    The probability, differential, and integral scattering cross sections of the 1{sup 1}S→2{sup 1}S and 1{sup 1}S→2{sup 1}P transitions of helium have been calculated in the first Born approximation. The projectile-target interactions depending on the temperature and the density of plasma are described by the Debye-Hückel model. Wave functions of the target before and after collision were modeled by non orthogonal Hartree-Fock orbitals. The wave functions parameters are calculated with the Ritz variational method. We improve our unscreened first Born approximation integral cross sections by using the BE-scaled (B stands for binding energy and E excitation energy) method. The second Born approximation has also been used to calculate the excitation cross sections in Debye plasma. Our calculations are compared to other theoretical and experimental results where applicable.

  5. Options for Cryogenic Load Cooling with Forced Flow Helium Circulation

    SciTech Connect

    Peter Knudsen, Venkatarao Ganni, Roberto Than

    2012-06-01

    Cryogenic pumps designed to circulate super-critical helium are commonly deemed necessary in many super-conducting magnet and other cooling applications. Acknowledging that these pumps are often located at the coldest temperature levels, their use introduces risks associated with the reliability of additional rotating machinery and an additional load on the refrigeration system. However, as it has been successfully demonstrated, this objective can be accomplished without using these pumps by the refrigeration system, resulting in lower system input power and improved reliability to the overall cryogenic system operations. In this paper we examine some trade-offs between using these pumps vs. using the refrigeration system directly with examples of processes that have used these concepts successfully and eliminated using such pumps

  6. Symmetric And Non-Symmetric Muonic Helium Atoms Studies

    SciTech Connect

    Mohammadi, S.

    2011-10-28

    The ground state hyperfine structure and other properties are calculated for muonic helium atoms ({sup 3}He{sup +2}{mu}{sup -}e{sup -} or {sup 4}He{sup +2}{mu}{sup -}e{sup -}) with the use of some local properties of the wave functions in the domains where two particles are close to each other or far away. Simple wave functions incorporating these properties with one variational parameter is developed. The calculated values for hyperfine structure, energy and average interparticle distances in ground state are compared with the correlation function hyper-spherical harmonic method and multibox variational approach. The obtained results are very close to the values calculated by mentioned methods, giving strong indications that the proposed wave functions provide relatively accurate values.

  7. Effect of helium on the electronic structure of palladium tritide

    SciTech Connect

    Gupta, R.P.; Gupta, M.

    1998-12-31

    Tritium is usually stored in the form of a metal tritide since it is safe to handle in this form, easily recoverable, and further large quantities of tritium can be stored. However, since tritium is radioactive it decays into {sup 3}He and an electron. Helium recoil energy in this reaction is very small, and not enough to create defects. The authors have performed ab-initio electronic structure calculations that show that in PdT, a considerable amount of {sup 3}He can be accommodated at the octahedral interstitial sites where it is produced. Their calculations also show that the presence of {sup 3}He results in an overall enhancement in the strength of the metal-tritium bonding that leads to the lowering of the plateau pressure. They also find that there is a weakening of the metal-metal bonds due to the repulsive interaction with {sup 3}He.

  8. MANGANESE DIOXIDE METHOD FOR PREPARATION OF PROTACTINIUM

    DOEpatents

    Katzin, L.I.

    1958-08-12

    A method of obtaining U/sup 233/ is described. An aqueous solution of neutriln irradiated thoriunn is treated by forming tberein a precipitate of manganese dioxide which carries and thus separates the Pa/sup 233/ from the solution. The carrier precipitate so formed is then dissolved in an acidic solution containing a reducing agent sufficiently electronegative to reduce the tetravalent manganese to the divalent state. Further purification of the Pa/sup 233/ may be obtained by forming another manganese dioxide carrier precipitate and subsequently dissolving it. Ater a sufficient number of such cycles have brought the Pa/sup 233/ to the desired purity, the solution is aged, allowing the formation ot U/sup 233/ by radioaetive decay. A manganese dioxide precipitate is then formed in the U/sup 233/ containing solution. This precipitate carries down any remaining Pa/sup 233/ thus leaving the separated U/sup 233/solution, from whieh it may be easily recovered.

  9. Polymers for metal extractions in carbon dioxide

    DOEpatents

    DeSimone, Joseph M.; Tumas, William; Powell, Kimberly R.; McCleskey, T. Mark; Romack, Timothy J.; McClain, James B.; Birnbaum, Eva R.

    2001-01-01

    A composition useful for the extraction of metals and metalloids comprises (a) carbon dioxide fluid (preferably liquid or supercritical carbon dioxide); and (b) a polymer in the carbon dioxide, the polymer having bound thereto a ligand that binds the metal or metalloid; with the ligand bound to the polymer at a plurality of locations along the chain length thereof (i.e., a plurality of ligands are bound at a plurality of locations along the chain length of the polymer). The polymer is preferably a copolymer, and the polymer is preferably a fluoropolymer such as a fluoroacrylate polymer. The extraction method comprises the steps of contacting a first composition containing a metal or metalloid to be extracted with a second composition, the second composition being as described above; and then extracting the metal or metalloid from the first composition into the second composition.

  10. Evaluation of the Gas Turbine Modular Helium Reactor

    SciTech Connect

    Not Available

    1994-02-01

    Recent advances in gas-turbine and heat exchanger technology have enhanced the potential for a Modular Helium Reactor (MHR) incorporating a direct gas turbine (Brayton) cycle for power conversion. The resulting Gas Turbine Modular Helium Reactor (GT-MHR) power plant combines the high temperature capabilities of the MHR with the efficiency and reliability of modern gas turbines. While the passive safety features of the steam cycle MHR (SC-MHR) are retained, generation efficiencies are projected to be in the range of 48% and steam power conversion systems, with their attendant complexities, are eliminated. Power costs are projected to be reduced by about 20%, relative to the SC-MHR or coal. This report documents the second, and final, phase of a two-part evaluation that concluded with a unanimous recommendation that the direct cycle (DC) variant of the GT-MHR be established as the commercial objective of the US Gas-Cooled Reactor Program. This recommendation has been endorsed by industrial and utility participants and accepted by the US Department of Energy (DOE). The Phase II effort, documented herein, concluded that the DC GT-MHR offers substantial technical and economic advantages over both the IDC and SC systems. Both the DC and IDC were found to offer safety advantages, relative to the SC, due to elimination of the potential for water ingress during power operations. This is the dominant consequence event for the SC. The IDC was judged to require somewhat less development than the direct cycle, while the SC, which has the greatest technology base, incurs the least development cost and risk. While the technical and licensing requirements for the DC were more demanding, they were judged to be incremental and feasible. Moreover, the DC offers significant performance and cost improvements over the other two concepts. Overall, the latter were found to justify the additional development needs.

  11. Superconducting cable cooling system by helium gas at two pressures

    DOEpatents

    Dean, John W.

    1977-01-01

    Thermally contacting, oppositely streaming, cryogenic fluid streams in the same enclosure in a closed cycle that changes the fluid from a cool high pressure helium gas to a cooler reduced pressure helium gas in an expander so as to be at different temperature ranges and pressures respectively in go and return legs that are in thermal contact with each other and in thermal contact with a longitudinally extending superconducting transmission line enclosed in the same cable enclosure that insulates the line from the ambient at a temperature T.sub.1. By first circulating the fluid from a refrigerator at one end of the line as a cool gas at a temperature range T.sub.2 to T.sub.3 in the go leg, then circulating the gas through an expander at the other end of the line where the gas becomes a cooler gas at a reduced pressure and at a reduced temperature T.sub.4 and finally by circulating the cooler gas back again to the refrigerator in a return leg at a temperature range T.sub.4 to T.sub.5, while in thermal contact with the gas in the go leg, and in the same enclosure therewith for compression into a higher pressure gas at T.sub.2 in a closed cycle, where T.sub.2 >T.sub.3 and T.sub.5 >T.sub.4, the fluid leaves the enclosure in the go leg as a gas at its coldest point in the go leg, and the temperature distribution is such that the line temperature decreases along its length from the refrigerator due to the cooling from the gas in the return leg.

  12. Facile time-of-flight methods for characterizing pulsed superfluid helium droplet beams

    SciTech Connect

    He, Yunteng; Zhang, Jie; Li, Yang; Freund, William M.; Kong, Wei

    2015-08-15

    We present two facile time-of-flight (TOF) methods of detecting superfluid helium droplets and droplets with neutral dopants. Without an electron gun and with only a heated filament and pulsed electrodes, the electron impact ionization TOF mass spectrometer can resolve ionized helium clusters such as He{sub 2}{sup +} and He{sub 4}{sup +}, which are signatures of superfluid helium droplets. Without ionizing any helium atoms, multiphoton non-resonant laser ionization of CCl{sub 4} doped in superfluid helium droplets at 266 nm generates complex cluster ions of dopant fragments with helium atoms, including (He){sub n}C{sup +}, (He){sub n}Cl{sup +}, and (He){sub n}CCl{sup +}. Using both methods, we have characterized our cryogenic pulsed valve—the Even-Lavie valve. We have observed a primary pulse with larger helium droplets traveling at a slower speed and a rebound pulse with smaller droplets at a faster speed. In addition, the pickup efficiency of dopant is higher for the primary pulse when the nozzle temperature is higher than 13 K, and the total time duration of the doped droplet pulse is only on the order of 20 μs. These results stress the importance of fast and easy characterization of the droplet beam for sensitive measurements such as electron diffraction of doped droplets.

  13. Preparation and thermal desorption properties of dc sputtered zirconium-hydrogen-helium thin films

    SciTech Connect

    Wei, Y. C.; Shi, L. Q.; Zhang, L.; He, Z. J.; Zhang, B.; Wang, L. B.

    2008-11-15

    We developed a new approach for preparing hydrogen and helium co-containing zirconium films (Zr-H-He) to simulate aging metal tritides. We also studied the effect of hydrogen on helium behavior, in which we applied direct current magnetron sputtering in a mixture of working gases (helium, argon, and hydrogen). The amount and depth profile of helium and hydrogen trapped in the films were determined using the elastic recoil detection analysis. The microstructure and surface morphology of the Zr-H-He films were studied by x-ray diffraction, transmission electron microscopy, and atomic force microscopy. To investigate the effect of hydrogen on the thermal release behavior of helium in the Zr film, thermal desorption spectrometry (TDS) was used, which revealed a similar desorption behavior to aged tritides. TDS experiments showed that the spectra were constituted by low-temperature peaks around 300 deg. C and high temperature peaks above 750 deg. C. Furthermore, the solid-phase {alpha} to {delta} transformation changed the shapes of the high-temperature peaks related to microstates of helium bubbles and caused the peak with a massive helium release shift toward lower temperature obviously.

  14. Project Profile: 10-Megawatt Supercritical Carbon Dioxide Turbine...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    aim to demonstrate a multi-megawatt power cycle using supercritical carbon dioxide (s-CO2) as the working fluid. The use of carbon dioxide instead of steam allows higher...

  15. Crystal structure and compressibility of lead dioxide up to 140...

    Office of Scientific and Technical Information (OSTI)

    Crystal structure and compressibility of lead dioxide up to 140 GPa Citation Details In-Document Search Title: Crystal structure and compressibility of lead dioxide up to 140 GPa ...

  16. Cavity morphology in a Ni based superalloy under heavy ion irradiation with hot pre-injected helium. II

    SciTech Connect

    Zhang, He; Yao, Zhongwen, E-mail: yaoz@me.queensu.ca; Daymond, Mark R. [Department of Mechanical and Materials Engineering, Queen's University Kingston, Ontario K7L 3N6 (Canada); Kirk, Marquis A. [Material Science Division, Argonne National Laboratory Argonne, Illinois 60439 (United States)

    2014-03-14

    In the current investigation, TEM in-situ heavy ion (1?MeV Kr{sup 2+}) irradiation with helium pre-injected at elevated temperature (400?C) was conducted to simulate in-reactor neutron irradiation induced damage in CANDU spacer material Inconel X-750, in an effort to understand the effects of helium on irradiation induced cavity microstructures. Three different quantities of helium, 400 appm, 1000 appm, and 5000 appm, were pre-injected directly into TEM foils at 400?C. The samples containing helium were then irradiated in-situ with 1?MeV Kr{sup 2+} at 400?C to a final dose of 5.4 dpa (displacement per atom). Cavities were formed from the helium injection solely and the cavity density and size increased with increasing helium dosage. In contrast to previous heavy ion irradiations with cold pre-injected helium, heterogeneous nucleation of cavities was observed. During the ensuing heavy ion irradiation, dynamical observation showed noticeable size increase in cavities which nucleated close to the grain boundaries. A bubble-void transformation was observed after Kr{sup 2+} irradiation to high dose (5.4?dpa) in samples containing 1000 appm and 5000 appm helium. Cavity distribution was found to be consistent with in-reactor neutron irradiation induced cavity microstructures. This implies that the distribution of helium is greatly dependent on the injection temperature, and helium pre-injection at high temperature is preferred for simulating the migration of the transmutation produced helium.

  17. Remote reactor repair: GTA (gas tungsten Arc) weld cracking caused by entrapped helium

    SciTech Connect

    Kanne, W.R. Jr.

    1988-01-01

    A repair patch was welded to the wall of a nuclear reactor tank using remotely controlled thirty-foot long robot arms. Further repair was halted when gas tungsten arc (GTA) welds joining type 304L stainless steel patches to the 304 stainless steel wall developed toe cracks in the heat-affected zone (HAZ). The role of helium in cracking was investigated using material with entrapped helium from tritium decay. As a result of this investigation, and of an extensive array of diagnostic tests performed on reactor tank wall material, helium embrittlement was shown to be the cause of the toe cracks.

  18. Effects of helium content of microstructural development in Type 316 stainless steel under neutron irradiation

    SciTech Connect

    Maziasz, P.J.

    1985-11-01

    This work investigated the sensitivity of microstructural evolution, particularly precipitate development, to increased helium content during thermal aging and during neutron irradiation. Helium (110 at. ppM) was cold preinjected into solution annealed (SA) DO-heat type 316 stainess steel (316) via cyclotron irradiation. These specimens were then exposed side by side with uninjected samples. Continuous helium generation was increased considerably relative to EBR-II irradiation by irradiation in HFIR. Data were obtained from quantitative analytical electron microscopy (AEM) in thin foils and on extraction replicas. 480 refs., 86 figs., 19 tabs.

  19. DEUTERIUM, TRITIUM, AND HELIUM DESORPTION FROM AGED TITANIUM TRITIDES. PART I.

    SciTech Connect

    Shanahan, K; Jeffrey Holder, J

    2006-07-10

    Six new samples of tritium-aged bulk titanium have been examined by thermal desorption and isotope exchange chemistry. The discovery of a lower temperature hydrogen desorption state in these materials, previously reported, has been confirmed in one of the new samples. The helium release of the samples shows the more severe effects obtained from longer aging periods, i.e. higher initial He/M ratios. Several of the more aged samples were spontaneously releasing helium. Part I will discuss the new results on the new lower temperature hydrogen desorption state found in one more extensively studied sample. Part II will discuss the hydrogen/helium release behavior of the remaining samples.

  20. DEUTERIUM, TRITIUM, AND HELIUM DESORPTION FROM AGED TITANIUM TRITIDES. PART II.

    SciTech Connect

    Shanahan, K; Jeffrey Holder, J

    2006-08-17

    Six new samples of tritium-aged bulk titanium have been examined by thermal desorption and isotope exchange chemistry. The discovery of a lower temperature hydrogen desorption state in these materials, previously reported, has been confirmed in one of the new samples. The helium release of the samples shows the more severe effects obtained from longer aging periods, i.e. higher initial He/M ratios. Several of the more aged samples were spontaneously releasing helium. Part I discussed the new results on the new lower temperature hydrogen desorption state found in one more extensively studied sample. Part II will discuss the hydrogen/helium release behavior of the remaining samples.

  1. Continuum-scale Modeling of Hydrogen and Helium Bubble Growth in Metals |

    Office of Environmental Management (EM)

    Department of Energy Continuum-scale Modeling of Hydrogen and Helium Bubble Growth in Metals Continuum-scale Modeling of Hydrogen and Helium Bubble Growth in Metals Presentation from the 34th Tritium Focus Group Meeting held in Idaho Falls, Idaho on September 23-25, 2014. Continuum-Scale Modeling of Hydrogen and Helium Bubble Growth in Metals (2.2 MB) More Documents & Publications H-Sensors and Fusion Work at SNL-CA Low-temperature Swelling in LWR Internal Components: Current Data and

  2. Geothermal Startup Will Put Carbon Dioxide to Good Use

    Energy.gov [DOE]

    Geothermal power holds enormous opportunities to provide affordable, clean energy that avoids greenhouse gases like carbon dioxide (CO2).

  3. Helium bubble evolution in a Zr–Sn–Nb–Fe–Cr alloy during post-annealing: An in-situ investigation

    SciTech Connect

    Shen, H.H.; Peng, S.M.; Chen, B.; Naab, F.N.; Sun, G.A.; Zhou, W.; Xiang, X.; Sun, K.; Zu, X.T.

    2015-09-15

    The formation of helium bubbles is considered to be detrimental to the mechanical performance of the nuclear materials. The growth behaviors of helium bubbles in a helium ion implanted Zr–Sn–Nb–Fe–Cr alloy with respect to the helium fluence and subsequently annealing procedure were investigated by in-situ transmission electron microscopy. In the as-implanted sample, the measured size distributions of the helium bubbles are consistent with the simulated helium concentrations. Moreover, the mean size of the helium bubbles increases with the increase of the irradiation temperatures and the helium fluence. The in-situ heating study performed in a transmission electron microscope indicates that the mean size of the helium bubbles increase slowly below 923 K and dramatically above 923 K. The coarsening mechanism of the helium bubbles in the alloy is suggested based on the study. - Highlights: • Helium bubble growth in zirconium with annealing was in-situ investigated in TEM. • The mean helium bubble size increase with helium fluence and annealing temperature. • Helium bubble size distribution is same as that of helium concentration by SRIM. • Mean bubble size increases slowly and quickly with temperature below and above 923 K. • The growth mechanism of the helium bubbles in Zr alloy has been discussed.

  4. Array of titanium dioxide nanostructures for solar energy utilization

    SciTech Connect

    Qiu, Xiaofeng; Parans Paranthaman, Mariappan; Chi, Miaofang; Ivanov, Ilia N; Zhang, Zhenyu

    2014-12-30

    An array of titanium dioxide nanostructures for solar energy utilization includes a plurality of nanotubes, each nanotube including an outer layer coaxial with an inner layer, where the inner layer comprises p-type titanium dioxide and the outer layer comprises n-type titanium dioxide. An interface between the inner layer and the outer layer defines a p-n junction.

  5. Acid sorption regeneration process using carbon dioxide

    DOEpatents

    King, C. Judson; Husson, Scott M.

    2001-01-01

    Carboxylic acids are sorbed from aqueous feedstocks onto a solid adsorbent in the presence of carbon dioxide under pressure. The acids are freed from the sorbent phase by a suitable regeneration method, one of which is treating them with an organic alkylamine solution thus forming an alkylamine-carboxylic acid complex which thermally decomposes to the desired carboxylic acid and the alkylamine.

  6. Optimization and Comparison of Direct and Indirect Supercritical Carbon Dioxide Power Plant Cycles for Nuclear Applications

    SciTech Connect

    Edwin A. Harvego; Michael G. McKellar

    2011-11-01

    There have been a number of studies involving the use of gases operating in the supercritical mode for power production and process heat applications. Supercritical carbon dioxide (CO2) is particularly attractive because it is capable of achieving relatively high power conversion cycle efficiencies in the temperature range between 550 C and 750 C. Therefore, it has the potential for use with any type of high-temperature nuclear reactor concept, assuming reactor core outlet temperatures of at least 550 C. The particular power cycle investigated in this paper is a supercritical CO2 Recompression Brayton Cycle. The CO2 Recompression Brayton Cycle can be used as either a direct or indirect power conversion cycle, depending on the reactor type and reactor outlet temperature. The advantage of this cycle when compared to the helium Brayton cycle is the lower required operating temperature; 550 C versus 850 C. However, the supercritical CO2 Recompression Brayton Cycle requires an operating pressure in the range of 20 MPa, which is considerably higher than the required helium Brayton cycle operating pressure of 8 MPa. This paper presents results of analyses performed using the UniSim process analyses software to evaluate the performance of both a direct and indirect supercritical CO2 Brayton Recompression cycle for different reactor outlet temperatures. The direct supercritical CO2 cycle transferred heat directly from a 600 MWt reactor to the supercritical CO2 working fluid supplied to the turbine generator at approximately 20 MPa. The indirect supercritical CO2 cycle assumed a helium-cooled Very High Temperature Reactor (VHTR), operating at a primary system pressure of approximately 7.0 MPa, delivered heat through an intermediate heat exchanger to the secondary indirect supercritical CO2 Brayton Recompression cycle, again operating at a pressure of about 20 MPa. For both the direct and indirect cycles, sensitivity calculations were performed for reactor outlet temperature

  7. Note: Control of liquid helium supply to cryopanels of Kolkata superconducting cyclotron

    SciTech Connect

    Bhattacharyya, T. K. Pal, G.

    2015-02-15

    The Kolkata superconducting cyclotron utilises liquid helium to cool the main magnet niobium-titanium (NbTi) coil and the cryopanels. Three liquid helium cooled cryopanels, placed inside the dees of the radio-frequency system, maintain the high vacuum in the acceleration region of the superconducting cyclotron. The small cryostat placed inside the cryogenic distribution manifold located at the basement of the superconducting cyclotron building supplies liquid helium in parallel branches to three cold heads, used for cooling their associated cryopanels. The level in the cryostat has to be maintained at an optimum value to ensure uninterrupted flow of liquid helium to these three cold heads. This paper describes the transfer function of the overall system, its tuning parameters, and discusses the actual control of cryostat level by using these parameters.

  8. Evaluation of helium impurity impacts on Spent Nuclear Fuel project processes (OCRWM)

    SciTech Connect

    SHERRELL, D.L.

    1999-09-21

    This document identifies the types and quantities of impurities that may be present within helium that is introduced into multi-canister overpacks (MCO)s by various SNF Project facilities, including, but not limited to the Cold Vacuum Drying (CVD) Facility (CVDF). It then evaluates possible impacts of worst case impurity inventories on MCO drying, transportation, and storage processes. Based on the evaluation results, this document: (1) concludes that the SNF Project helium procurement specification can be a factor-of-ten less restrictive than a typical vendor's standard offering (99.96% pure versus the vendor's 99.997% pure standard offering); (2) concludes that the CVDF's current 99.5% purity requirement is adequate to control the quality of the helium that is delivered to the MCO by the plant's helium distribution system; and (3) recommends specific impurity limits for both of the above cases.

  9. Research and development of a helium-4 based solar neutrino detector

    SciTech Connect

    Lanou, R.E.; Maris, H.J.; Seidel, G.M.

    1990-12-01

    We report on work accomplished in the first 30 months of a research and development program to investigate the feasibility of a new technique to detect solar neutrinos in superfluid helium. Accomplishments include the successful completion of design, construction and operation of the entire cryogenic, mechanical and electronic apparatus. During the last several months we have begun a series of experiments in superfluid helium to test the method. Experimental results include the first observation of the combined physical processes essential to the detection technique: ballistic roton generation by energetic charged particles, quantum evaporation of helium at a free surface and bolometric detection of the evaporated helium by physisorption on a cold silicon wafer. Additional results are also presented.

  10. Helium release rates and ODH calculations from RHIC magnet cooling line failure

    SciTech Connect

    Liaw, C.J.; Than, Y.; Tuozzolo, J.

    2011-03-28

    A catastrophic failure of the magnet cooling lines, similar to the LHC superconducting bus failure incident, could discharge cold helium into the RHIC tunnel and cause an Oxygen Deficiency Hazard (ODH) problem. A SINDA/FLUINT{reg_sign} model, which simulated the 4.5K/4 atm helium flowing through the magnet cooling system distribution lines, then through a line break into the insulating vacuum volumes and discharging via the reliefs into the RHIC tunnel, had been developed. Arc flash energy deposition and heat load from the ambient temperature cryostat surfaces are included in the simulations. Three typical areas: the sextant arc, the Triplet/DX/D0 magnets, and the injection area, had been analyzed. Results, including helium discharge rates, helium inventory loss, and the resulting oxygen concentration in the RHIC tunnel area, are reported. Good agreement had been achieved when comparing the simulation results, a RHIC sector depressurization test measurement, and some simple analytical calculations.

  11. Exploring the isopycnal mixing and helium-heat paradoxes in a suite of Earth System Models

    DOE PAGES [OSTI]

    Gnanadesikan, A.; Abernathey, R.; Pradal, M.-A.

    2014-11-20

    This paper uses a suite of Earth System models which simulate the distribution of He isotopes and radiocarbon to examine two paradoxes in Earth science. The helium-heat paradox refers to the fact that helium emissions to the deep ocean are far lower than would be expected given the rate of geothermal heating, since both are thought to be the result of radioactive decay in the earth's interior. The isopycnal mixing paradox comes from the fact that many theoretical parameterizations of the isopycnal mixing coefficient ARedi that link it to baroclinic instability project it to be small (of order a fewmore » hundred m2 s−1) in the ocean interior away from boundary currents. However, direct observations using tracers and floats (largely in the upper ocean) suggest that values of this coefficient are an order of magnitude higher. Because helium isotopes equilibrate rapidly with the atmosphere, but radiocarbon equilibrates slowly, it might be thought that resolving the isopycnal mixing paradox in favor of the higher observational estimates of ARedi might also solve the helium paradox. In this paper we show that this is not the case. In a suite of models with different spatially constant and spatially varying values of ARedi the distribution of radiocarbon and helium isotopes is sensitive to the value of ARedi. However, away from strong helium sources in the Southeast Pacific, the relationship between the two is not sensitive, indicating that large-scale advection is the limiting process for removing helium and radiocarbon from the deep ocean. The helium isotopes, in turn, suggest a higher value of ARedi in the deep ocean than is seen in theoretical parameterizations based on baroclinic growth rates. We argue that a key part of resolving the isopycnal mixing paradox is to abandon the idea that ARedi has a direct relationship to local baroclinic instability and to the so called "thickness" mixing coefficient AGM.« less

  12. Radon and helium in soil gases in the Phlegraean Fields, central Italy

    SciTech Connect

    Lombardi, S. ); Reimer, G.M. )

    1990-05-01

    The distribution and migration of radon and helium soil-gas concentrations in the Phlegraean Fields, Italy, are controlled by the tectonic features of the area. Radon is supplied from surficial sources and helium has both surficial and deep origins. There is no direct correlation between the two noble gases on a point-to-point basis but the areal distribution of both gases is similar, suggesting that the distribution is controlled primarily by fractures and movement of geothermal fluids.

  13. Performance Testing of Jefferson Lab 12 GeV Helium Screw Compressors

    SciTech Connect

    Knudsen, P.; Ganni, V.; Dixon, K.; Norton, R.; Creel, J.

    2015-08-10

    Oil injected screw compressors have essentially superseded all other types of compressors in modern helium refrigeration systems due to their large displacement capacity, reliability, minimal vibration, and capability of handling helium's high heat of compression. At the present state of compressor system designs for helium refrigeration systems, typically two-thirds of the lost input power is due to the compression system. It is important to understand the isothermal and volumetric efficiencies of these machines to help properly design the compression system to match the refrigeration process. It is also important to identify those primary compressor skid exergetic loss mechanisms which may be reduced, thereby offering the possibility of significantly reducing the input power to helium refrigeration processes which are extremely energy intensive. This paper summarizes the results collected during the commissioning of the new compressor system for Jefferson Lab's (JLab's) 12 GeV upgrade. The compressor skid packages were designed by JLab and built to print by industry. They incorporate a number of modifications not typical of helium screw compressor packages and most importantly allow a very wide range of operation so that JLab's patented Floating Pressure Process can be fully utilized. This paper also summarizes key features of the skid design that allow this process and facilitate the maintenance and reliability of these helium compressor systems.

  14. The initiation and propagation of helium detonations in white dwarf envelopes

    SciTech Connect

    Shen, Ken J. [Department of Astronomy and Theoretical Astrophysics Center, University of California, Berkeley, CA 94720 (United States); Moore, Kevin, E-mail: kenshen@astro.berkeley.edu [Department of Applied Mathematics and Statistics, University of California, Santa Cruz, CA 95064 (United States)

    2014-12-10

    Detonations in helium-rich envelopes surrounding white dwarfs have garnered attention as triggers of faint thermonuclear '.Ia' supernovae and double detonation Type Ia supernovae. However, recent studies have found that the minimum size of a hotspot that can lead to a helium detonation is comparable to, or even larger than, the white dwarf's pressure scale height, casting doubt on the successful ignition of helium detonations in these systems. In this paper, we examine the previously neglected effects of C/O pollution and a full nuclear reaction network, and we consider hotspots with spatially constant pressure in addition to constant density hotspots. We find that the inclusion of these effects significantly decreases the minimum hotspot size for helium-rich detonation ignition, making detonations far more plausible during turbulent shell convection or during double white dwarf mergers. The increase in burning rate also decreases the minimum shell mass in which a helium detonation can successfully propagate and alters the composition of the shell's burning products. The ashes of these low-mass shells consist primarily of silicon, calcium, and unburned helium and metals and may explain the high-velocity spectral features observed in most Type Ia supernovae.

  15. Performance Testing of Jefferson Lab 12 GeV Helium Screw Compressors

    DOE PAGES [OSTI]

    Knudsen, P.; Ganni, V.; Dixon, K.; Norton, R.; Creel, J.

    2015-08-10

    Oil injected screw compressors have essentially superseded all other types of compressors in modern helium refrigeration systems due to their large displacement capacity, reliability, minimal vibration, and capability of handling helium's high heat of compression. At the present state of compressor system designs for helium refrigeration systems, typically two-thirds of the lost input power is due to the compression system. It is important to understand the isothermal and volumetric efficiencies of these machines to help properly design the compression system to match the refrigeration process. It is also important to identify those primary compressor skid exergetic loss mechanisms which maymore » be reduced, thereby offering the possibility of significantly reducing the input power to helium refrigeration processes which are extremely energy intensive. This paper summarizes the results collected during the commissioning of the new compressor system for Jefferson Lab's (JLab's) 12 GeV upgrade. The compressor skid packages were designed by JLab and built to print by industry. They incorporate a number of modifications not typical of helium screw compressor packages and most importantly allow a very wide range of operation so that JLab's patented Floating Pressure Process can be fully utilized. This paper also summarizes key features of the skid design that allow this process and facilitate the maintenance and reliability of these helium compressor systems.« less

  16. Atomic-scale mechanisms of helium bubble hardening in iron

    DOE PAGES [OSTI]

    Osetskiy, Yury N.; Stoller, Roger E.

    2015-06-03

    Generation of helium due to (n,α) transmutation reactions changes the response of structural materials to neutron irradiation. The whole process of radiation damage evolution is affected by He accumulation and leads to significant changes in the material s properties. A population of nanometric He-filled bubbles affects mechanical properties and the impact can be quite significant because of their high density. Understanding how these basic mechanisms affect mechanical properties is necessary for predicting radiation effects. In this paper we present an extensive study of the interactions between a moving edge dislocation and bubbles using atomic-scale modeling. We focus on the effectmore » of He bubble size and He concentration inside bubbles. Thus, we found that ability of bubbles to act as an obstacle to dislocation motion is close to that of voids when the He-to-vacancy ratio is in the range from 0 to 1. A few simulations made at higher He contents demonstrated that the interaction mechanism is changed for over-pressurized bubbles and they become weaker obstacles. The results are discussed in light of post-irradiation materials testing.« less

  17. Atomic-scale mechanisms of helium bubble hardening in iron

    SciTech Connect

    Osetskiy, Yury N.; Stoller, Roger E.

    2015-06-03

    Generation of helium due to (n,α) transmutation reactions changes the response of structural materials to neutron irradiation. The whole process of radiation damage evolution is affected by He accumulation and leads to significant changes in the material s properties. A population of nanometric He-filled bubbles affects mechanical properties and the impact can be quite significant because of their high density. Understanding how these basic mechanisms affect mechanical properties is necessary for predicting radiation effects. In this paper we present an extensive study of the interactions between a moving edge dislocation and bubbles using atomic-scale modeling. We focus on the effect of He bubble size and He concentration inside bubbles. Thus, we found that ability of bubbles to act as an obstacle to dislocation motion is close to that of voids when the He-to-vacancy ratio is in the range from 0 to 1. A few simulations made at higher He contents demonstrated that the interaction mechanism is changed for over-pressurized bubbles and they become weaker obstacles. The results are discussed in light of post-irradiation materials testing.

  18. Dynamics of two-electron excitations in helium

    SciTech Connect

    Caldwell, C.D.; Menzel, A.; Frigo, S.P.

    1997-04-01

    Excitation of both electrons in helium offers a unique window for studying electron correlation at the most basic level in an atom in which these two electrons and the nucleus form a three-body system. The authors utilized the first light available at the U-8 undulator-SGM monochromator beamline to investigate the dynamic parameters, partial cross sections, differential cross sections, and photoelectron angular distribution parameters ({beta}), with a high resolving power for the photon beam and at the highly differential level afforded by the use of their electron spectrometer. In parallel, they carried out detailed calculations of the relevant properties by a theoretical approach that is based on the hyperspherical close-coupling method. Partial photoionization cross sections {sigma}{sub n}, and photoelectron angular distributions {beta}{sub n} were measured for all possible final ionic states He{sup +}(n) in the region of the double excitations N(K,T){sup A} up to the N=5 threshold. At a photon energy bandpass of 12 meV below the thresholds N=3, 4, and 5, this level of differentiation offers the most critical assessment of the dynamics of the two-electron excitations to date. The experimental data were seen to be very well described by the most advanced theoretical calculations.

  19. Performance Characterization of the Production Facility Prototype Helium Flow System

    SciTech Connect

    Woloshun, Keith Albert; Dale, Gregory E.; Dalmas, Dale Allen; Romero, Frank Patrick

    2015-12-16

    The roots blower in use at ANL for in-beam experiments and also at LANL for flow tests was sized for 12 mm diameter disks and significantly less beam heating. Currently, the disks are 29 mm in diameter, with a 12 mm FWHM Gaussian beam spot at 42 MeV and 2.86 μA on each side of the target, 5.72 μA total. The target design itself is reported elsewhere. With the increased beam heating, the helium flow requirement increased so that a larger blower was need for a mass flow rate of 400 g/s at 2.76 MPa (400 psig). An Aerzen GM 12.4 blower was selected, and is currently being installed at the LANL facility for target and component flow testing. This report describes this blower/motor/pressure vessel package and the status of the facility preparations. Blower performance (mass flow rate as a function of loop pressure drop) was measured at 4 blower speeds. Results are reported below.

  20. USE OF THE MODULAR HELIUM REACTOR FOR HYDROGEN PRODUCTION

    SciTech Connect

    SCHULTZ,KR

    2003-09-01

    OAK-B135 A significant ''Hydrogen Economy'' is predicted that will reduce our dependence on petroleum imports and reduce pollution and greenhouse gas emissions. Hydrogen is an environmentally attractive fuel that has the potential to displace fossil fuels, but contemporary hydrogen production is primarily based on fossil fuels. The author has recently completed a three-year project for the US Department of Energy (DOE) whose objective was to ''define an economically feasible concept for production of hydrogen, using an advanced high-temperature nuclear reactor as the energy source''. Thermochemical water-slitting, a chemical process that accomplishes the decomposition of water into hydrogen and oxygen, met this objective. The goal of the first phase of this study was to evaluate thermochemical processes which offer the potential for efficient, cost-effective, large-scale production of hydrogen, and to select one for further detailed consideration. They selected the Sulfur-Iodine cycle. In the second phase, they reviewed all the basic reactor types for suitability to provide the high temperature heat needed by the selected thermochemical water splitting cycle and chose the helium gas-cooled reactor. In the third phase they designed the chemical flowsheet for the thermochemical process and estimated the efficiency and cost of the process and the projected cost of producing hydrogen. These results are summarized in this report.

  1. SULPHUR DIOXIDE LEACHING OF URANIUM CONTAINING MATERIAL

    DOEpatents

    Thunaes, A.; Rabbits, F.T.; Hester, K.D.; Smith, H.W.

    1958-12-01

    A process is described for extracting uranlum from uranium containing material, such as a low grade pitchblende ore, or mill taillngs, where at least part of the uraniunn is in the +4 oxidation state. After comminuting and magnetically removing any entrained lron particles the general material is made up as an aqueous slurry containing added ferric and manganese salts and treated with sulfur dioxide and aeration to an extent sufficient to form a proportion of oxysulfur acids to give a pH of about 1 to 2 but insufficient to cause excessive removal of the sulfur dioxide gas. After separating from the solids, the leach solution is adjusted to a pH of about 1.25, then treated with metallic iron in the presence of a precipitant such as a soluble phosphate, arsonate, or fluoride.

  2. Extraction of furfural with carbon dioxide

    SciTech Connect

    Gamse, T.; Marr, R.; Froeschl, F.; Siebenhofer, M.

    1997-01-01

    A new approach to separate furfural from aqueous waste has been investigated. Recovery of furfural and acetic acid from aqueous effluents of a paper mill has successfully been applied on an industrial scale since 1981. The process is based on the extraction of furfural and acetic acid by the solvent trooctylphosphineoxide (TOPO). Common extraction of both substances may cause the formation of resin residues. Improvement was expected by selective extraction of furfural with chlorinated hydrocarbons, but ecological reasons stopped further development of this project. The current investigation is centered in the evaluation of extraction of furfural by supercritical carbon dioxide. The influence of temperature and pressure on the extraction properties has been worked out. The investigation has considered the multi-component system furfural-acetic acid-water-carbon dioxide. Solubility of furfural in liquid and supercritical carbon dioxide has been measured, and equilibrium data for the ternary system furfural-water-CO{sub 2} as well as for the quaternary system furfural-acetic acid-water-CO{sub 2} have been determined. A high-pressure extraction column has been used for evaluation of mass transfer rates.

  3. ALTERNATIVES TO HELIUM-3 FOR NEUTRON MULTIPLICITY DETECTORS

    SciTech Connect

    Ely, James H.; Siciliano, Edward R.; Swinhoe, Martyn T.

    2012-02-07

    Collaboration between the Pacific Northwest National Laboratory (PNNL) and the Los Alamos National Laboratory (LANL) is underway to evaluate neutron detection technologies that might replace the high-pressure helium (3He) tubes currently used in neutron multiplicity counter for safeguards applications. The current stockpile of 3He is diminishing and alternatives are needed for a variety of neutron detection applications including multiplicity counters. The first phase of this investigation uses a series of Monte Carlo calculations to simulate the performance of an existing neutron multiplicity counter configuration by replacing the 3He tubes in a model for that counter with candidate alternative technologies. These alternative technologies are initially placed in approximately the same configuration as the 3He tubes to establish a reference level of performance against the 3He-based system. After these reference-level results are established, the configurations of the alternative models will be further modified for performance optimization. The 3He model for these simulations is the one used by LANL to develop and benchmark the Epithermal Neutron Multiplicity Counter (ENMC) detector, as documented by H.O. Menlove, et al. in the 2004 LANL report LA-14088. The alternative technologies being evaluated are the boron-tri-fluoride-filled proportional tubes, boron-lined tubes, and lithium coated materials previously tested as possible replacements in portal monitor screening applications, as documented by R.T. Kouzes, et al. in the 2010 PNNL report PNNL-72544 and NIM A 623 (2010) 1035–1045. The models and methods used for these comparative calculations will be described and preliminary results shown

  4. Assessment of Embrittlement of VHTR Structural Alloys in Impure Helium Environments

    SciTech Connect

    Crone, Wendy; Cao, Guoping; Sridhara, Kumar

    2013-05-31

    The helium coolant in high-temperature reactors inevitably contains low levels of impurities during steady-state operation, primarily consisting of small amounts of H{sub 2}, H{sub 2}O, CH{sub 4}, CO, CO{sub 2}, and N{sub 2} from a variety of sources in the reactor circuit. These impurities are problematic because they can cause significant long-term corrosion in the structural alloys used in the heat exchangers at elevated temperatures. Currently, the primary candidate materials for intermediate heat exchangers are Alloy 617, Haynes 230, Alloy 800H, and Hastelloy X. This project will evaluate the role of impurities in helium coolant on the stress-assisted grain boundary oxidation and creep crack growth in candidate alloys at elevated temperatures. The project team will: • Evaluate stress-assisted grain boundary oxidation and creep crack initiation and crack growth in the temperature range of 500-850°C in a prototypical helium environment. • Evaluate the effects of oxygen partial pressure on stress-assisted grain boundary oxidation and creep crack growth in impure helium at 500°C, 700°C, and 850°C respectively. • Characterize the microstructure of candidate alloys after long-term exposure to an impure helium environment in order to understand the correlation between stress-assisted grain boundary oxidation, creep crack growth, material composition, and impurities in the helium coolant. • Evaluate grain boundary engineering as a method to mitigate stress-assisted grain boundary oxidation and creep crack growth of candidate alloys in impure helium. The maximum primary helium coolant temperature in the high-temperature reactor is expected to be 850-1,000°C.Corrosion may involve oxidation, carburization, or decarburization mechanisms depending on the temperature, oxygen partial pressure, carbon activity, and alloy composition. These corrosion reactions can substantially affect long-term mechanical properties such as crack- growth rate and fracture

  5. Method of immobilizing carbon dioxide from gas streams

    DOEpatents

    Holladay, David W.; Haag, Gary L.

    1979-01-01

    This invention is a method for rapidly and continuously immobilizing carbon dioxide contained in various industrial off-gas streams, the carbon dioxide being immobilized as dry, stable, and substantially water-insoluble particulates. Briefly, the method comprises passing the gas stream through a fixed or fluidized bed of hydrated barium hydroxide to remove and immobilize the carbon dioxide by converting the bed to barium carbonate. The method has several important advantages: it can be conducted effectively at ambient temperature; it provides a very rapid reaction rate over a wide range of carbon dioxide concentrations; it provides high decontamination factors; and it has a high capacity for carbon dioxide. The invention is especially well suited for the removal of radioactive carbon dioxide from off-gases generated by nuclear-fuel reprocessing facilities and nuclear power plants.

  6. The CNG process: Acid gas removal with liquid carbon dioxide

    SciTech Connect

    Liu, Y.C.; Auyang, L.; Brown, W.R.

    1987-01-01

    The CNG acid gas removal process has two unique features: the absorption of sulfur-containing compounds and other trace contaminants with liquid carbon dioxide, and the regeneration of pure liquid carbon dioxide by triple-point crystallization. The process is especially suitable for treating gases which contain large amounts of carbon dioxide and much smaller amounts (relative to carbon dioxide) of hydrogen sulfide. Capital and energy costs are lower than conventional solvent processes. Further, products of the CNG process meet stringent purity specifications without undue cost penalties. A process demonstration unit has been constructed and operated to demonstrate the two key steps of the CNG process. Hydrogen sulfide and carbonyl sulfide removal from gas streams with liquid carbon dioxide absorbent to sub-ppm concentrations has been demonstrated. The production of highly purified liquid carbon dioxide (less than 0.1 ppm total contaminant) by triple-point crystallization also has been demonstrated.

  7. Helium embrittlement model and program plan for weldability of ITER materials

    SciTech Connect

    Louthan, M.R. Jr.; Kanne, W.R. Jr.; Tosten, M.H.; Rankin, D.T.; Cross, B.J.

    1997-02-01

    This report presents a refined model of how helium embrittles irradiated stainless steel during welding. The model was developed based on experimental observations drawn from experience at the Savannah River Site and from an extensive literature search. The model shows how helium content, stress, and temperature interact to produce embrittlement. The model takes into account defect structure, time, and gradients in stress, temperature and composition. The report also proposes an experimental program based on the refined helium embrittlement model. A parametric study of the effect of initial defect density on the resulting helium bubble distribution and weldability of tritium aged material is proposed to demonstrate the roll that defects play in embrittlement. This study should include samples charged using vastly different aging times to obtain equivalent helium contents. Additionally, studies to establish the minimal sample thickness and size are needed for extrapolation to real structural materials. The results of these studies should provide a technical basis for the use of tritium aged materials to predict the weldability of irradiated structures. Use of tritium charged and aged material would provide a cost effective approach to developing weld repair techniques for ITER components.

  8. Forced Two-Phase Helium Cooling Scheme for the Mu2e Transport Solenoid

    SciTech Connect

    Tatkowski, G.; Cheban, S.; Dhanaraj, N.; Evbota, D.; Lopes, M.; Nicol, T.; Sanders, R.; Schmitt, R.; Voirin, E.

    2015-01-01

    The Mu2e Transport Solenoid (TS) is an S-shaped magnet formed by two separate but similar magnets, TS-u and TS-d. Each magnet is quarter-toroid shaped with a centerline radius of approximately 3 m utilizing a helium cooling loop consisting of 25 to 27 horizontal-axis rings connected in series. This cooling loop configuration has been deemed adequate for cooling via forced single phase liquid helium; however it presents major challenges to forced two-phase flow such as “garden hose” pressure drop, concerns of flow separation from tube walls, difficulty of calculation, etc. Even with these disadvantages, forced two-phase flow has certain inherent advantages which make it a more attractive option than forced single phase flow. It is for this reason that the use of forced two-phase flow was studied for the TS magnets. This paper will describe the analysis using helium-specific pressure drop correlations, conservative engineering approach, helium properties calculated and updated at over fifty points, and how the results compared with those in literature. Based on the findings, the use of forced-two phase helium is determined to be feasible for steady-state cooling of the TS solenoids

  9. Elucidation of fundamental properties of helium in metals by nuclear magnetic resonance techniques

    SciTech Connect

    Abell, G.C.

    1990-01-01

    The nuclear magnetic resonance (NMR) properties of very high density {sup 3}He in metals are discussed in the context of the corresponding properties in relatively high density bulk {sup 3}He. In particular, the effects of the {sup 3}He diffusion on the contribution of the {sup 3}He-{sup 3}He dipolar interaction to the lineshape and to the spin-lattice relaxation parameter (T{sub 1}) are described. It is shown that the temperature dependence of the lineshape and of T{sub 1} are independent sources of information about helium density and also about helium diffusivity. Moreover, T{sub 1} is shown to be a sensitive indicator of melting transitions in bulk {sup 3}He. Palladium tritide is presented as a model system for NMR studies of {sup 3}He in metals. Experimental NMR studies of this system reveal behavior analogous to what has been observed for bulk helium. Evidence for a {sup 3}He phase transition near 250 K is provided by the temperature dependence of T{sub 1}. Assuming this to be a melting transition, a density is obtained from the bulk helium EOS that is in good agreement with theory and with swelling measurements on related metal tritides. {sup 3}He NMR measurements have also provided information about the density distribution, helium diffusivity, and mean bubble size in palladium tritide. 22 refs., 8 figs.

  10. Helium release and microstructural changes in Er(D,T)2-x3Hex films).

    SciTech Connect

    Gelles, D. S.; Browning, James Frederick; Snow, Clark Sheldon; Banks, James Clifford; Mangan, Michael A.; Rodriguez, Mark Andrew; Brewer, Luke N.; Kotula, Paul Gabriel

    2007-12-01

    Er(D,T){sub 2-x} {sup 3}He{sub x}, erbium di-tritide, films of thicknesses 500 nm, 400 nm, 300 nm, 200 nm, and 100 nm were grown and analyzed by Transmission Electron Microscopy, X-Ray Diffraction, and Ion Beam Analysis to determine variations in film microstructure as a function of film thickness and age, due to the time-dependent build-up of {sup 3}He in the film from the radioactive decay of tritium. Several interesting features were observed: One, the amount of helium released as a function of film thickness is relatively constant. This suggests that the helium is being released only from the near surface region and that the helium is not diffusing to the surface from the bulk of the film. Two, lenticular helium bubbles are observed as a result of the radioactive decay of tritium into {sup 3}He. These bubbles grow along the [111] crystallographic direction. Three, a helium bubble free zone, or 'denuded zone' is observed near the surface. The size of this region is independent of film thickness. Four, an analysis of secondary diffraction spots in the Transmission Electron Microscopy study indicate that small erbium oxide precipitates, 5-10 nm in size, exist throughout the film. Further, all of the films had large erbium oxide inclusions, in many cases these inclusions span the depth of the film.

  11. Haverford College Researchers Create Carbon Dioxide-Separating Polymer

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Haverford College Researchers Create Carbon Dioxide-Separating Polymer Haverford College Researchers Create Carbon Dioxide-Separating Polymer August 1, 2012 Rebecca Raber, rraber@haverford.edu, +1 610 896 1038 gtoc.jpg Carbon dioxide gas separation is important for many environmental and energy applications. Molecular dynamics simulations are used to characterize a two-dimensional hydrocarbon polymer, PG-ES1, that uses a combination of surface adsorption and narrow pores to separate carbon

  12. ARM - Lesson Plans: Plant Growth and Carbon Dioxide

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Plant Growth and Carbon Dioxide Outreach Home Room News Publications Traditional Knowledge Kiosks Barrow, Alaska Tropical Western Pacific Site Tours Contacts Students Study Hall About ARM Global Warming FAQ Just for Fun Meet our Friends Cool Sites Teachers Teachers' Toolbox Lesson Plans Lesson Plans: Plant Growth and Carbon Dioxide Objective The objective is to show how carbon dioxide in the air affects plant growth. Materials Each group of students will need the following: Graph paper Pencil

  13. Carbonation Mechanism of Reservoir Rock by Supercritical Carbon Dioxide |

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Department of Energy Carbonation Mechanism of Reservoir Rock by Supercritical Carbon Dioxide Carbonation Mechanism of Reservoir Rock by Supercritical Carbon Dioxide Project Objectives: Elucidate comprehensively the carbonation reaction mechanisms between supercritical carbon dioxide (scCO2) and reservoir rocks consisting of different mineralogical compositions in aqueous and non-aqueous environments at temperatures of up to 250ºC, and to develop chemical modeling of CO2-reservior rock

  14. Case Study: Transcritical Carbon Dioxide Supermarket Refrigeration Systems

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    | Department of Energy Transcritical Carbon Dioxide Supermarket Refrigeration Systems Case Study: Transcritical Carbon Dioxide Supermarket Refrigeration Systems This case study documents one year of operating experience with a transcritical carbon dioxide (TC CO2) booster refrigeration system at Delhaize America's Hannaford supermarket location in Turner, Maine. This supermarket, which began operation in June 2013, is the first supermarket installation in the U.S. of a TC CO2 booster

  15. Fact #948: October 24, 2016 Carbon Dioxide Emissions from Transportation

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Exceeded those from the Electric Power Sector for the First Time in 38 Years - Dataset | Department of Energy 8: October 24, 2016 Carbon Dioxide Emissions from Transportation Exceeded those from the Electric Power Sector for the First Time in 38 Years - Dataset Fact #948: October 24, 2016 Carbon Dioxide Emissions from Transportation Exceeded those from the Electric Power Sector for the First Time in 38 Years - Dataset Excel file and dataset for Carbon Dioxide Emissions from Transportation

  16. Geochemical Impacts of Carbon Dioxide, Brine, Trace Metal and...

    Office of Scientific and Technical Information (OSTI)

    Carbon Dioxide, Brine, Trace Metal and Organic Leakage into an Unconfined, Oxidizing Limestone Aquifer Citation Details In-Document Search Title: Geochemical Impacts of Carbon ...

  17. Molecular Simulation of Carbon Dioxide Nanodroplets on Clay in...

    Office of Scientific and Technical Information (OSTI)

    Citation Details In-Document Search Title: Molecular Simulation of Carbon Dioxide Nanodroplets on Clay in Deep Saline Aquifers. Authors: Tenney, Craig M. Publication Date: ...

  18. Molecular Simulation of Carbon Dioxide Nanodroplets on Clay Surfaces...

    Office of Scientific and Technical Information (OSTI)

    Surfaces in Deep Saline Aquifers. Citation Details In-Document Search Title: Molecular Simulation of Carbon Dioxide Nanodroplets on Clay Surfaces in Deep Saline Aquifers. Authors: ...

  19. Carbon Dioxide Capture and Storage Demonstration in Developing...

    OpenEI (Open Energy Information) [EERE & EIA]

    Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Carbon Dioxide Capture and Storage Demonstration in Developing Countries: Analysis of Key Policy Issues and Barriers...

  20. Imaging Wellbore Cement Degradation by Carbon Dioxide under Geologic...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Imaging Wellbore Cement Degradation by Carbon Dioxide under Geologic Sequestration Conditions Using X-ray Computed Microtomography Citation Details In-Document ...

  1. High-Efficiency Receivers for Supercritical Carbon Dioxide Cycles

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Brayton Energy's supercritical carbon dioxide (s-CO 2 ) solar receiver has the potential to significantly improve reliability, increase efficiency, and reduce costs of CSP systems. ...

  2. Comprehensive study of carbon dioxide adsorption in the metal...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Comprehensive study of carbon dioxide adsorption in the metal-organic frameworks M2(dobdc) (M ... physisorptive interaction with the framework surface and sheds more light on the ...

  3. Beneficial Use of Carbon Dioxide in Precast Concrete Production...

    Office of Scientific and Technical Information (OSTI)

    of Carbon Dioxide in Precast Concrete Production Shao, Yixin 36 MATERIALS SCIENCE Clean Coal Technology Coal - Environmental Processes Clean Coal Technology Coal - Environmental...

  4. Method for carbon dioxide sequestration (Patent) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    interbeds, providing an injection well into the formation and injecting supercritical carbon dioxide (SC--CO.sub.2) into the injection well under conditions of ...

  5. Carbon dioxide absorbent and method of using the same

    DOEpatents

    Perry, Robert James; O'Brien, Michael Joseph

    2014-06-10

    In accordance with one aspect, the present invention provides a composition which contains the amino-siloxane structures I, or III, as described herein. The composition is useful for the capture of carbon dioxide from process streams. In addition, the present invention provides methods of preparing the amino-siloxane composition. Another aspect of the present invention provides methods for reducing the amount of carbon dioxide in a process stream employing the amino-siloxane compositions of the invention, as species which react with carbon dioxide to form an adduct with carbon dioxide.

  6. Carbon dioxide absorbent and method of using the same

    DOEpatents

    Perry, Robert James; O'Brien, Michael Joseph

    2015-12-29

    In accordance with one aspect, the present invention provides a composition which contains the amino-siloxane structures I, or III, as described herein. The composition is useful for the capture of carbon dioxide from process streams. In addition, the present invention provides methods of preparing the amino-siloxane composition. Another aspect of the present invention provides methods for reducing the amount of carbon dioxide in a process stream employing the amino-siloxane compositions of the invention, as species which react with carbon dioxide to form an adduct with carbon dioxide.

  7. Theoretical analysis of uranium-doped thorium dioxide: Introduction...

    Office of Scientific and Technical Information (OSTI)

    polarization Citation Details In-Document Search Title: Theoretical analysis of uranium-doped thorium dioxide: Introduction of a thoria force field with explicit polarization ...

  8. Project Profile: Supercritical Carbon Dioxide Turbo-Expander...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Supercritical Carbon Dioxide Turbo-Expander and Heat Exchangers Project Profile: ... Concentrating Solar Power (CSP) SunShot R&D funding opportunity announcement (FOA), are ...

  9. Synthesis, Structure, and Carbon Dioxide Capture Properties of...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Synthesis, Structure, and Carbon Dioxide Capture Properties of Zeolitic Imidazolate Frameworks Previous Next List Anh Phan, Christian J. Doonan, Fernando J. Uribe-Romo, Carolyn B....

  10. Organoclay Sorbent for Removal of Carbon Dioxide from Gas Streams...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    carbon dioxide (CO2) from low temperature and low pressure gas streams. In this process, the clay minerals are modified with organic materials to retain the amines....

  11. Thermo Scientific Sulfur Dioxide Analyzer Instrument Handbook (Technical

    Office of Scientific and Technical Information (OSTI)

    Report) | SciTech Connect Sulfur Dioxide Analyzer Instrument Handbook Citation Details In-Document Search Title: Thermo Scientific Sulfur Dioxide Analyzer Instrument Handbook The Sulfur Dioxide Analyzer measures sulfur dioxide based on absorbance of UV light at one wavelength by SO2 molecules which then decay to a lower energy state by emitting UV light at a longer wavelength. Specifically, SO2 + hυ1 →SO2 *→SO2 + hυ2 The emitted light is proportional to the concentration of SO2 in the

  12. Carbon Dioxide Information Analysis Center (CDIAC)-Fossil Fuel...

    OpenEI (Open Energy Information) [EERE & EIA]

    Fuel CO2 Emissions Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Carbon Dioxide Information Analysis Center (CDIAC)-Fossil Fuel CO2 Emissions AgencyCompany...

  13. Carbon Dioxide Emissions Associated with Bioenergy and Other...

    OpenEI (Open Energy Information) [EERE & EIA]

    and Other Biogenic Sources Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Carbon Dioxide Emissions Associated with Bioenergy and Other Biogenic Sources AgencyCompany...

  14. Haverford College Researchers Create Carbon Dioxide-Separating...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    dioxide gas separation is important for many environmental and energy applications. Molecular dynamics simulations are used to characterize a two-dimensional hydrocarbon...

  15. Carbon Dioxide Geological Sequestration in Fractured Porous Rocks

    Office of Scientific and Technical Information (OSTI)

    Training and Research on Probabilistic Hydro-Thermo-Mechanical Modeling of Carbon Dioxide Geological Sequestration in Fractured Porous Rocks Gutierrez, Marte 54 ENVIRONMENTAL...

  16. A Novel System for Carbon Dioxide Capture Utilizing Electrochemical...

    Office of Scientific and Technical Information (OSTI)

    Electric Power and Carbon-Dioxide Separation (CEPACS) system, under a contract from ... The unique chemistry of carbonate fuel cells offers an innovative approach for separation ...

  17. OSTIblog Articles in the carbon dioxide Topic | OSTI, US Dept...

    Office of Scientific and Technical Information (OSTI)

    regions and seasons, increasing intensity and frequency of storm events, flooding and... Related Topics: carbon dioxide, carbon sequestration, climate change, greenhouse gases

  18. CarBen Version 3: Multisector Carbon Dioxide Emissions Accounting...

    OpenEI (Open Energy Information) [EERE & EIA]

    Name: CarBen Version 3: Multisector Carbon Dioxide Emissions Accounting Tool Focus Area: Geothermal Power Topics: Policy, Deployment, & Program Impact Website: www.netl.doe.gov...

  19. Fast, Efficient Isothermal Redox to Split Water or Carbon Dioxide...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Fast, Efficient Isothermal Redox to Split Water or Carbon Dioxide using Solar Energy ... the hercynite cycle allows faster, more efficient cycling and less wear on the equipment ...

  20. U.S. Energy-Related Carbon Dioxide Emissions, 2014

    Energy Information Administration (EIA) (indexed site)

    Related Carbon Dioxide Emissions, 2014 November 2015 Independent Statistics & Analysis www.eia.gov U.S. Department of Energy Washington, DC 20585 November 2015 U.S. Energy Information Administration | U.S. Energy-Related Carbon Dioxide Emissions, 2014 1 November 2015 U.S. Energy Information Administration | U.S. Energy-Related Carbon Dioxide Emissions, 2014 2 November 2015 U.S. Energy Information Administration | U.S. Energy-Related Carbon Dioxide Emissions, 2014 3 November 2015 U.S. Energy

  1. Commissioning of helium compression system for the 12 GeV refrigerator

    SciTech Connect

    Knudsen, Peter N.; Ganni, Venkatarao; Dixon, Kelly D.; Norton, Robert O.; Creel, Jonathan D.; Arenius, Dana M.

    2014-01-01

    The compressor system used for the Jefferson Lab (JLab) 12 GeV upgrade, also known as the CHL-2 compressor system, incorporates many design changes to the typical compressor skid design to improve the efficiency, reliability and maintainability from previous systems. These include a considerably smaller bulk oil separator design that does not use coalescing elements/media, automated control of cooling oil injection based on the helium discharge temperature, a helium after-cooler design that is designed for and promotes coalescing of residual oil and a variable speed bearing oil pump to reduce oil bypass. The CHL-2 helium compression system has five compressors configured with four pressure levels that supports the three pressure levels in the cold box. This paper will briefly review several of these improvements and discuss some of the recent commissioning results.

  2. Ab initio study of formation, migration and binding properties of helium-vacancy clusters in aluminum

    SciTech Connect

    Yang, Li; Zu, Xiaotao T.; Gao, Fei

    2008-08-01

    Ab initio calculations based on density functional theory have been performed to study the dissolution and migration of helium, and the stability of small helium-vacancy clusters HenVm (n, m=0 to 4) in aluminum. The results indicate that the octahedral configuration is more stable than the tetrahedral. Interstitial helium atoms are predicted to have attractive interactions and jump between two octahedral sites via an intermediate tetrahedral site with low migration energy of 0.10 eV. The binding energies of an interstitial He atom and an isolated vacancy to a HenVm cluster are also obtained from the calculated formation energies of the clusters. We find that the divacancy and tri--vacancy clusters are not stable, but He atoms can increase the stability of vacancy clusters. The interactions of He atoms with a vacancy are found to be in good agreement with the experimental results.

  3. Method for extracting and sequestering carbon dioxide

    DOEpatents

    Rau, Gregory H. (Castro Valley, CA); Caldeira, Kenneth G. (Livermore, CA)

    2005-05-10

    A method and apparatus to extract and sequester carbon dioxide (CO.sub.2) from a stream or volume of gas wherein said method and apparatus hydrates CO.sub.2, and reacts the resulting carbonic acid with carbonate. Suitable carbonates include, but are not limited to, carbonates of alkali metals and alkaline earth metals, preferably carbonates of calcium and magnesium. Waste products are metal cations and bicarbonate in solution or dehydrated metal salts, which when disposed of in a large body of water provide an effective way of sequestering CO.sub.2 from a gaseous environment.

  4. Apparatus for extracting and sequestering carbon dioxide

    DOEpatents

    Rau, Gregory H. (Castro Valley, CA); Caldeira, Kenneth G. (Livermore, CA)

    2010-02-02

    An apparatus and method associated therewith to extract and sequester carbon dioxide (CO.sub.2) from a stream or volume of gas wherein said apparatus hydrates CO.sub.2 and reacts the resulting carbonic acid with carbonate. Suitable carbonates include, but are not limited to, carbonates of alkali metals and alkaline earth metals, preferably carbonates of calcium and magnesium. Waste products are metal cations and bicarbonate in solution or dehydrated metal salts, which when disposed of in a large body of water provide an effective way of sequestering CO.sub.2 from a gaseous environment.

  5. Catalytic conversion of sulfur dioxide and trioxide

    SciTech Connect

    Solov'eva, E.L.; Shenfel'd, B.E.; Kuznetsova, S.M.; Khludenev, A.G.

    1987-11-10

    The reclamation and utilization of sulfur-containing wastes from the flue gas of fossil-fuel power plants and the subsequent reduction in sulfur emission is addressed in this paper. The authors approach this problem from the standpoint of the catalytic oxidation of sulfur dioxide on solid poison-resistant catalysts with subsequent sorption of the sulfur trioxide and its incorporation into the manufacture of sulfuric acid. The catalyst they propose is a polymetallic dust-like waste from the copper-smelting industry comprised mainly of iron and copper oxides. Experiments with this catalyst were carried out using multifactorial experiment planning.

  6. Capture of carbon dioxide by hybrid sorption

    DOEpatents

    Srinivasachar, Srivats

    2014-09-23

    A composition, process and system for capturing carbon dioxide from a combustion gas stream. The composition has a particulate porous support medium that has a high volume of pores, an alkaline component distributed within the pores and on the surface of the support medium, and water adsorbed on the alkaline component, wherein the proportion of water in the composition is between about 5% and about 35% by weight of the composition. The process and system contemplates contacting the sorbent and the flowing gas stream together at a temperature and for a time such that some water remains adsorbed in the alkaline component when the contact of the sorbent with the flowing gas ceases.

  7. Molecular-dynamics analysis of mobile helium cluster reactions near surfaces of plasma-exposed tungsten

    SciTech Connect

    Hu, Lin; Maroudas, Dimitrios; Hammond, Karl D.; Wirth, Brian D.

    2015-10-28

    We report the results of a systematic atomic-scale analysis of the reactions of small mobile helium clusters (He{sub n}, 4 ≤ n ≤ 7) near low-Miller-index tungsten (W) surfaces, aiming at a fundamental understanding of the near-surface dynamics of helium-carrying species in plasma-exposed tungsten. These small mobile helium clusters are attracted to the surface and migrate to the surface by Fickian diffusion and drift due to the thermodynamic driving force for surface segregation. As the clusters migrate toward the surface, trap mutation (TM) and cluster dissociation reactions are activated at rates higher than in the bulk. TM produces W adatoms and immobile complexes of helium clusters surrounding W vacancies located within the lattice planes at a short distance from the surface. These reactions are identified and characterized in detail based on the analysis of a large number of molecular-dynamics trajectories for each such mobile cluster near W(100), W(110), and W(111) surfaces. TM is found to be the dominant cluster reaction for all cluster and surface combinations, except for the He{sub 4} and He{sub 5} clusters near W(100) where cluster partial dissociation following TM dominates. We find that there exists a critical cluster size, n = 4 near W(100) and W(111) and n = 5 near W(110), beyond which the formation of multiple W adatoms and vacancies in the TM reactions is observed. The identified cluster reactions are responsible for important structural, morphological, and compositional features in the plasma-exposed tungsten, including surface adatom populations, near-surface immobile helium-vacancy complexes, and retained helium content, which are expected to influence the amount of hydrogen re-cycling and tritium retention in fusion tokamaks.

  8. Cryogenic system with GM cryocooler for krypton, xenon separation from hydrogen-helium purge gas

    SciTech Connect

    Chu, X. X.; Zhang, D. X.; Qian, Y.; Liu, W.; Zhang, M. M.; Xu, D.

    2014-01-29

    In the thorium molten salt reactor (TMSR), fission products such as krypton, xenon and tritium will be produced continuously in the process of nuclear fission reaction. A cryogenic system with a two stage GM cryocooler was designed to separate Kr, Xe, and H{sub 2} from helium purge gas. The temperatures of two stage heat exchanger condensation tanks were maintained at about 38 K and 4.5 K, respectively. The main fluid parameters of heat transfer were confirmed, and the structural heat exchanger equipment and cold box were designed. Designed concentrations after cryogenic separation of Kr, Xe and H{sub 2} in helium recycle gas are less than 1 ppb.

  9. Application of JLab 12GeV helium refrigeration system for the FRIB accelerator at MSU

    SciTech Connect

    Ganni, Venkatarao; Knudsen, Peter N.; Arenius, Dana M.; Casagrande, Fabio

    2014-01-01

    The planned approach to have a turnkey helium refrigeration system for the MSU-FRIB accelerator system, encompassing the design, fabrication, installation and commissioning of the 4.5-K refrigerator cold box(es), cold compression system, warm compression system, gas management, oil removal and utility/ancillary systems, was found to be cost prohibitive. Following JLab’s suggestion, MSU-FRIB accelerator management made a formal request to evaluate the applicability of the recently designed 12GeV JLab cryogenic system for this application. The following paper will outline the findings and the planned approach for the FRIB helium refrigeration system.

  10. Application of JLab 12GeV helium refrigeration system for the FRIB accelerator at MSU

    SciTech Connect

    Ganni, V.; Knudsen, P.; Arenius, D.; Casagrande, F.

    2014-01-29

    The planned approach to have a turnkey helium refrigeration system for the MSU-FRIB accelerator system, encompassing the design, fabrication, installation and commissioning of the 4.5-K refrigerator cold box(es), cold compression system, warm compression system, gas management, oil removal and utility/ancillary systems, was found to be cost prohibitive. Following JLab’s suggestion, MSU-FRIB accelerator management made a formal request to evaluate the applicability of the recently designed 12GeV JLab cryogenic system for this application. The following paper will outline the findings and the planned approach for the FRIB helium refrigeration system.

  11. SPHERICALLY SYMMETRIC NLTE MODEL ATMOSPHERES OF HOT HYDROGEN-HELIUM FIRST STARS

    SciTech Connect

    Kubat, Jiri

    2012-12-15

    We present results of our calculations of NLTE model stellar atmospheres for hot Population III stars composed of hydrogen and helium. We use our own computer code for the calculation of spherically symmetric NLTE model atmospheres in hydrostatic and radiative equilibrium. The model atmospheres are then used for the calculation of emergent fluxes. These fluxes serve to evaluate the flow of high-energy photons for energies higher than ionization energies of hydrogen and helium, the so-called ionizing photon fluxes. We also present the time evolution of the ionizing photon fluxes.

  12. Effect of helium growth and carbon impurities on the properties of aged metal tritides

    SciTech Connect

    McConville, G.T.; Menke, D.A.; West, D.; Woods, C.M.

    1995-10-01

    The interaction of tritium with metals is made complex by two phenomena. The beta decay in the metal produces {sup 3}He. The helium moves to form bubbles. We shall show that the growth of the bubbles produces a two stage swelling of the metal coming first from the appearance of the helium and second from the relaxation of the lattice disorder caused by the bubble growth. The second phenomenon is the steady state ion and free radical concentration in the tritium over gas which interacts with impurities on the metal surface. We shall show that the reaction rates are much faster than for normal hydrogen cleaning. 12 refs., 7 figs., 3 tabs.

  13. Ductile-brittle transition behavior of V-4Cr-4Ti irradiated in the dynamic helium charging experiment

    SciTech Connect

    Chung, H.M.; Nowicki, L.J.; Busch, D.E.

    1995-04-01

    The objective of this work is to determine the effect of simultaneous displacement damage and dynamically charged helium on the ductile-brittle transition behavior of V-4Cr-4Ti specimens irradiated to 18-31 dpa at 425-600{degrees}C in the Dynamic Helium Charging Experiment (DHCE).

  14. Effects of helium implantation on the tensile properties and microstructure of Ni₇₃P₂₇ metallic glass nanostructures

    SciTech Connect

    Liontas, Rachel; Gu, X. Wendy; Fu, Engang; Wang, Yongqiang; Li, Nan; Mara, Nathan; Greer, Julia R.

    2014-09-10

    We report fabrication and nanomechanical tension experiments on as-fabricated and helium-implanted ~130 nm diameter Ni₇₃P₂₇ metallic glass nano-cylinders. The nano-cylinders were fabricated by a templated electroplating process and implanted with He⁺ at energies of 50, 100, 150, and 200 keV to create a uniform helium concentration of ~3 at. % throughout the nano-cylinders. Transmission electron microscopy (TEM) imaging and through-focus analysis reveal that the specimens contained ~2 nm helium bubbles distributed uniformly throughout the nano-cylinder volume. In-situ tensile experiments indicate that helium-implanted specimens exhibit enhanced ductility as evidenced by a 2-fold increase in plastic strain over as-fabricated specimens, with no sacrifice in yield and ultimate tensile strengths. This improvement in mechanical properties suggests that metallic glasses may actually exhibit a favorable response to high levels of helium implantation.

  15. Effects of helium implantation on the tensile properties and microstructure of Ni₇₃P₂₇ metallic glass nanostructures

    DOE PAGES [OSTI]

    Liontas, Rachel; Gu, X. Wendy; Fu, Engang; Wang, Yongqiang; Li, Nan; Mara, Nathan; Greer, Julia R.

    2014-09-10

    We report fabrication and nanomechanical tension experiments on as-fabricated and helium-implanted ~130 nm diameter Ni₇₃P₂₇ metallic glass nano-cylinders. The nano-cylinders were fabricated by a templated electroplating process and implanted with He⁺ at energies of 50, 100, 150, and 200 keV to create a uniform helium concentration of ~3 at. % throughout the nano-cylinders. Transmission electron microscopy (TEM) imaging and through-focus analysis reveal that the specimens contained ~2 nm helium bubbles distributed uniformly throughout the nano-cylinder volume. In-situ tensile experiments indicate that helium-implanted specimens exhibit enhanced ductility as evidenced by a 2-fold increase in plastic strain over as-fabricated specimens, with nomore » sacrifice in yield and ultimate tensile strengths. This improvement in mechanical properties suggests that metallic glasses may actually exhibit a favorable response to high levels of helium implantation.« less

  16. Method for synthesis of titanium dioxide nanotubes using ionic liquids

    SciTech Connect

    Qu, Jun; Luo, Huimin; Dai, Sheng

    2013-11-19

    The invention is directed to a method for producing titanium dioxide nanotubes, the method comprising anodizing titanium metal in contact with an electrolytic medium containing an ionic liquid. The invention is also directed to the resulting titanium dioxide nanotubes, as well as devices incorporating the nanotubes, such as photovoltaic devices, hydrogen generation devices, and hydrogen detection devices.

  17. Deep-Burn Modular Helium Reactor Fuel Development Plan

    SciTech Connect

    McEachern, D

    2002-12-02

    This document contains the workscope, schedule and cost for the technology development tasks needed to satisfy the fuel and fission product transport Design Data Needs (DDNs) for the Gas Turbine-Modular Helium Reactor (GT-MHR), operating in its role of transmuting transuranic (TRU) nuclides in spent fuel discharged from commercial light-water reactors (LWRs). In its application for transmutation, the GT-MHR is referred to as the Deep-Burn MHR (DB-MHR). This Fuel Development Plan (FDP) describes part of the overall program being undertaken by the U.S. Department of Energy (DOE), utilities, and industry to evaluate the use of the GT-MHR to transmute transuranic nuclides from spent nuclear fuel. The Fuel Development Plan (FDP) includes the work on fuel necessary to support the design and licensing of the DB-MHR. The FDP is organized into ten sections. Section 1 provides a summary of the most important features of the plan, including cost and schedule information. Section 2 describes the DB-MHR concept, the features of its fuel and the plan to develop coated particle fuel for transmutation. Section 3 describes the knowledge base for fabrication of coated particles, the experience with irradiation performance of coated particle fuels, the database for fission product transport in HTGR cores, and describes test data and calculations for the performance of coated particle fuel while in a repository. Section 4 presents the fuel performance requirements in terms of as-manufactured quality and performance of the fuel coatings under irradiation and accident conditions. These requirements are provisional because the design of the DB-MHR is in an early stage. However, the requirements are presented in this preliminary form to guide the initial work on the fuel development. Section 4 also presents limits on the irradiation conditions to which the coated particle fuel can be subjected for the core design. These limits are based on past irradiation experience. Section 5 describes

  18. Evaluation and Optimization of a Supercritical Carbon Dioxide Power Conversion Cycle for Nuclear Applications

    SciTech Connect

    Edwin A. Harvego; Michael G. McKellar

    2011-05-01

    There have been a number of studies involving the use of gases operating in the supercritical mode for power production and process heat applications. Supercritical carbon dioxide (CO2) is particularly attractive because it is capable of achieving relatively high power conversion cycle efficiencies in the temperature range between 550°C and 750°C. Therefore, it has the potential for use with any type of high-temperature nuclear reactor concept, assuming reactor core outlet temperatures of at least 550°C. The particular power cycle investigated in this paper is a supercritical CO2 Recompression Brayton Cycle. The CO2 Recompression Brayton Cycle can be used as either a direct or indirect power conversion cycle, depending on the reactor type and reactor outlet temperature. The advantage of this cycle when compared to the helium Brayton Cycle is the lower required operating temperature; 550°C versus 850°C. However, the supercritical CO2 Recompression Brayton Cycle requires an operating pressure in the range of 20 MPa, which is considerably higher than the required helium Brayton cycle operating pressure of 8 MPa. This paper presents results of analyses performed using the UniSim process analyses software to evaluate the performance of the supercritical CO2 Brayton Recompression Cycle for different reactor outlet temperatures. The UniSim model assumed a 600 MWt reactor power source, which provides heat to the power cycle at a maximum temperature of between 550°C and 750°C. The UniSim model used realistic component parameters and operating conditions to model the complete power conversion system. CO2 properties were evaluated, and the operating range for the cycle was adjusted to take advantage of the rapidly changing conditions near the critical point. The UniSim model was then optimized to maximize the power cycle thermal efficiency at the different maximum power cycle operating temperatures. The results of the analyses showed that power cycle thermal

  19. Carbon dioxide absorbent and method of using the same

    DOEpatents

    Perry, Robert James; Lewis, Larry Neil; O'Brien, Michael Joseph; Soloveichik, Grigorii Lev; Kniajanski, Sergei; Lam, Tunchiao Hubert; Lee, Julia Lam; Rubinsztajn, Malgorzata Iwona

    2011-10-04

    In accordance with one aspect, the present invention provides an amino-siloxane composition comprising at least one of structures I, II, III, IV or V said compositions being useful for the capture of carbon dioxide from gas streams such as power plant flue gases. In addition, the present invention provides methods of preparing the amino-siloxane compositions are provided. Also provided are methods for reducing the amount of carbon dioxide in a process stream employing the amino-siloxane compositions of the invention as species which react with carbon dioxide to form an adduct with carbon dioxide. The reaction of the amino-siloxane compositions provided by the present invention with carbon dioxide is reversible and thus, the method provides for multicycle use of said compositions.

  20. Table 5. Per capita energy-related carbon dioxide emissions by...

    Energy Information Administration (EIA) (indexed site)

    Per capita energy-related carbon dioxide emissions by State (2000-2011)" "metric tons of carbon dioxide per person" ,,,"Change" ,,,"2000 to 2011"...

  1. Table 2. 2011 State energy-related carbon dioxide emissions by...

    Energy Information Administration (EIA) (indexed site)

    2011 State energy-related carbon dioxide emissions by fuel " ,"million metric tons of carbon dioxide",,,,,"shares" "State","Coal","Petroleum","Natural Gas ","Total",,"Coal","Petrol...

  2. Table 3. 2011 State energy-related carbon dioxide emissions by...

    Energy Information Administration (EIA) (indexed site)

    2011 State energy-related carbon dioxide emissions by sector " "million metric tons of carbon dioxide" "State","Commercial","Electric Power","Residential","Industrial","Transportat...

  3. Table 1. State energy-related carbon dioxide emissions by year...

    Energy Information Administration (EIA) (indexed site)

    State energy-related carbon dioxide emissions by year (2000-2011)" "million metric tons of carbon dioxide" ,,,"Change" ,,,"2000 to 2011" "State",2000,2001,2002,...

  4. Energy-Related Carbon Dioxide Emissions at the State Level, 2000...

    Energy Information Administration (EIA) (indexed site)

    2 Table 4. 2013 state energy-related carbon dioxide emission shares by sector percent of ... Administration | Energy-Related Carbon Dioxide Emissions at the State Level, ...

  5. Energy-Related Carbon Dioxide Emissions at the State Level, 2000...

    Energy Information Administration (EIA) (indexed site)

    0 Table 3. 2013 state energy-related carbon dioxide emissions by sector million metric tons carbon dioxide State Commercial Electric Power Residential Industrial Transportation ...

  6. Helium bubble formation in ultrafine and nanocrystalline tungsten under different extreme conditions

    SciTech Connect

    El-atwani, O.; Hattar, Khalid Mikhiel; Hinks, J. A.; Greaves, G.; Harilal, S. S.; Hassanein, A.

    2014-12-25

    We investigated the effects of helium ion irradiation energy and sample temperature on the performance of grain boundaries as helium sinks in ultrafine grained and nanocrystalline tungsten. Irradiations were performed at displacement and non-displacement energies and at temperatures above and below that required for vacancy migration. Microstructural investigations were performed using Transmission Electron Microscopy (TEM) combined with either in-situ or ex-situ ion irradiation. Under helium irradiation at an energy which does not cause atomic displacements in tungsten (70 eV), regardless of temperature and thus vacancy migration conditions, bubbles were uniformly distributed with no preferential bubble formation on grain boundaries. Moreover, at energies that can cause displacements, bubbles were observed to be preferentially formed on the grain boundaries only at high temperatures where vacancy migration occurs. Under these conditions, the decoration of grain boundaries with large facetted bubbles occurred on nanocrystalline grains with dimensions less than 60 nm. Finally, we discuss the importance of vacancy supply and the formation and migration of radiation-induced defects on the performance of grain boundaries as helium sinks and the resulting irradiation tolerance of ultrafine grained and nanocrystalline tungsten to bubble formation.

  7. Simulation of streamers propagating along helium jets in ambient air: Polarity-induced effects

    SciTech Connect

    Naidis, G. V.

    2011-04-04

    Results of modeling of streamer propagation along helium jets for both positive and negative polarities of applied voltage are presented. Obtained patterns of streamer dynamics and structure in these two cases are similar to those observed in experiments with plasma jets.

  8. A comparison of hydrogen vs. helium glow discharge effects on fusion device first-wall conditioning

    SciTech Connect

    Dylla, H.F.

    1989-09-01

    Hydrogen- and deuterium-fueled glow discharges are used for the initial conditioning of magnetic fusion device vacuum vessels following evacuation from atmospheric pressure. Hydrogenic glow discharge conditioning (GDC) significantly reduces the near-surface concentration of simple adsorbates, such as H/sub 2/O, CO, and CH/sub 4/, and lowers ion-induced desorption coefficients by typically three orders of magnitude. The time evolution of the residual gas production observed during hydrogen-glow discharge conditioning of the carbon first-wall structure of the TFTR device is similar to the time evolution observed during hydrogen GDC of the initial first-wall configuration in TFTR, which was primarily stainless steel. Recently, helium GDC has been investigated for several wall-conditioning tasks on a number of tokamaks including TFTR. Helium GDC shows negligible impurity removal with stainless steel walls. For impurity conditioning with carbon walls, helium GDC shows significant desorption of H/sub 2/O, CO, and CO/sub 2/; however, the total desorption yield is limited to the monolayer range. In addition, helium GDC can be used to displace hydrogen isotopes from the near-surface region of carbon first-walls in order to lower hydrogenic retention and recycling. 38 refs., 6 figs.

  9. Ordinary SQUID interferometers and superfluid helium matter wave interferometers: The role of quantum fluctuations

    SciTech Connect

    Golovashkin, A. I.; Zherikhina, L. N. Tskhovrebov, A. M.; Izmailov, G. N.; Ozolin, V. V.

    2010-08-15

    When comparing the operation of a superfluid helium matter wave quantum interferometer (He SQUID) with that of an ordinary direct-current quantum interferometer (dc SQUID), we estimate their resolution limitation that correspond to quantum fluctuations. An alternative mode of operation of the interferometer as a unified macroquantum system is considered.

  10. Effect of kinetic energy on the doping efficiency of cesium cations into superfluid helium droplets

    SciTech Connect

    Chen, Lei; Zhang, Jie; Freund, William M.; Kong, Wei

    2015-07-28

    We present an experimental investigation of the effect of kinetic energy on the ion doping efficiency of superfluid helium droplets using cesium cations from a thermionic emission source. The kinetic energy of Cs{sup +} is controlled by the bias voltage of a collection grid collinearly arranged with the droplet beam. Efficient doping from ions with kinetic energies from 20 eV up to 480 V has been observed in different sized helium droplets. The relative ion doping efficiency is determined by both the kinetic energy of the ions and the average size of the droplet beam. At a fixed source temperature, the number of doped droplets increases with increasing grid voltage, while the relative ion doping efficiency decreases. This result implies that not all ions are captured upon encountering with a sufficiently large droplet, a deviation from the near unity doping efficiency for closed shell neutral molecules. We propose that this drop in ion doping efficiency with kinetic energy is related to the limited deceleration rate inside a helium droplet. When the source temperature changes from 14 K to 17 K, the relative ion doping efficiency decreases rapidly, perhaps due to the lack of viable sized droplets. The size distribution of the Cs{sup +}-doped droplet beam can be measured by deflection and by energy filtering. The observed doped droplet size is about 5 × 10{sup 6} helium atoms when the source temperature is between 14 K and 17 K.

  11. RECONCILING THE GALACTIC BULGE TURNOFF AGE DISCREPANCY WITH ENHANCED HELIUM ENRICHMENT

    SciTech Connect

    Nataf, David M.; Gould, Andrew P.

    2012-06-01

    We show that the factor {approx}2 discrepancy between spectroscopic and photometric age determinations of the Galactic bulge main-sequence turnoff can be naturally explained by positing an elevated helium enrichment for the bulge relative to that assumed by standard isochrones. Helium enhancement relative to standard isochrones is confirmed at the 2.3{sigma} level. We obtain an upper bound on the helium enrichment for the metal-rich ([Fe/H] Almost-Equal-To +0.30) stars of {Delta}Y Almost-Equal-To +0.11 relative to canonical expectations, given the requirement that the spectroscopic and photometric ages be consistent and the limiting condition of instantaneous star formation. We discuss phenomenological evidence that the bulge may have had a chemical evolution that is distinct from the solar neighborhood in this manner, and we make several testable predictions. Should this emerging picture of the bulge as helium-enhanced hold, it will require the development of new isochrones, new model atmospheres, and modified analysis and cosmological interpretation of the integrated light of other bulges and elliptical galaxies.

  12. Non-local thermodynamic equilibrium effects on isentropic coefficient in argon and helium thermal plasmas

    SciTech Connect

    Sharma, Rohit; Singh, Kuldip

    2014-03-15

    In the present work, two cases of thermal plasma have been considered; the ground state plasma in which all the atoms and ions are assumed to be in the ground state and the excited state plasma in which atoms and ions are distributed over various possible excited states. The variation of Z?, frozen isentropic coefficient and the isentropic coefficient with degree of ionization and non-equilibrium parameter ?(= T{sub e}/T{sub h}) has been investigated for the ground and excited state helium and argon plasmas at pressures 1?atm, 10?atm, and 100?atm in the temperature range from 6000?K to 60?000?K. For a given value of non-equilibrium parameter, the relationship of Z? with degree of ionization does not show any dependence on electronically excited states in helium plasma whereas in case of argon plasma this dependence is not appreciable till degree of ionization approaches 2. The minima of frozen isentropic coefficient shifts toward lower temperature with increase of non-equilibrium parameter for both the helium and argon plasmas. The lowering of non-equilibrium parameter decreases the frozen isentropic coefficient more emphatically in helium plasma at high pressures in comparison to argon plasma. The increase of pressure slightly reduces the ionization range over which isentropic coefficient almost remains constant and it does not affect appreciably the dependence of isentropic coefficient on non-equilibrium parameter.

  13. Helium bubble formation in ultrafine and nanocrystalline tungsten under different extreme conditions

    DOE PAGES [OSTI]

    El-atwani, O.; Hattar, Khalid Mikhiel; Hinks, J. A.; Greaves, G.; Harilal, S. S.; Hassanein, A.

    2014-12-25

    We investigated the effects of helium ion irradiation energy and sample temperature on the performance of grain boundaries as helium sinks in ultrafine grained and nanocrystalline tungsten. Irradiations were performed at displacement and non-displacement energies and at temperatures above and below that required for vacancy migration. Microstructural investigations were performed using Transmission Electron Microscopy (TEM) combined with either in-situ or ex-situ ion irradiation. Under helium irradiation at an energy which does not cause atomic displacements in tungsten (70 eV), regardless of temperature and thus vacancy migration conditions, bubbles were uniformly distributed with no preferential bubble formation on grain boundaries. Moreover,more » at energies that can cause displacements, bubbles were observed to be preferentially formed on the grain boundaries only at high temperatures where vacancy migration occurs. Under these conditions, the decoration of grain boundaries with large facetted bubbles occurred on nanocrystalline grains with dimensions less than 60 nm. Finally, we discuss the importance of vacancy supply and the formation and migration of radiation-induced defects on the performance of grain boundaries as helium sinks and the resulting irradiation tolerance of ultrafine grained and nanocrystalline tungsten to bubble formation.« less

  14. Statistical Properties of Inter-Series Mixing in Helium: From Integrability to Chaos

    SciTech Connect

    Pu''ttner, R.; Gremaud, B.; Delande, D.; Domke, M.; Martins, M.; Schlachter, A. S.; Kaindl, G.

    2001-04-23

    The photoionization spectrum of helium shows considerable complexity close to the double-ionization threshold. By analyzing the results from both our recent experiments and ab initio three- and one-dimensional calculations, we show that the statistical properties of the spacings between neighboring energy levels clearly display a transition towards quantum chaos.

  15. Helium, Iron and Electron Particle Transport and Energy Transport Studies on the TFTR Tokamak

    DOE R&D Accomplishments

    Synakowski, E. J.; Efthimion, P. C.; Rewoldt, G.; Stratton, B. C.; Tang, W. M.; Grek, B.; Hill, K. W.; Hulse, R. A.; Johnson, D .W.; Mansfield, D. K.; McCune, D.; Mikkelsen, D. R.; Park, H. K.; Ramsey, A. T.; Redi, M. H.; Scott, S. D.; Taylor, G.; Timberlake, J.; Zarnstorff, M. C. (Princeton Univ., NJ (United States). Plasma Physics Lab.); Kissick, M. W. (Wisconsin Univ., Madison, WI (United States))

    1993-03-01

    Results from helium, iron, and electron transport on TFTR in L-mode and Supershot deuterium plasmas with the same toroidal field, plasma current, and neutral beam heating power are presented. They are compared to results from thermal transport analysis based on power balance. Particle diffusivities and thermal conductivities are radially hollow and larger than neoclassical values, except possibly near the magnetic axis. The ion channel dominates over the electron channel in both particle and thermal diffusion. A peaked helium profile, supported by inward convection that is stronger than predicted by neoclassical theory, is measured in the Supershot The helium profile shape is consistent with predictions from quasilinear electrostatic drift-wave theory. While the perturbative particle diffusion coefficients of all three species are similar in the Supershot, differences are found in the L-Mode. Quasilinear theory calculations of the ratios of impurity diffusivities are in good accord with measurements. Theory estimates indicate that the ion heat flux should be larger than the electron heat flux, consistent with power balance analysis. However, theoretical values of the ratio of the ion to electron heat flux can be more than a factor of three larger than experimental values. A correlation between helium diffusion and ion thermal transport is observed and has favorable implications for sustained ignition of a tokamak fusion reactor.

  16. Molten uranium dioxide structure and dynamics

    DOE PAGES [OSTI]

    Skinner, L. B.; Parise, J. B.; Benmore, C. J.; Weber, J. K.R.; Williamson, M. A.; Tamalonis, A.; Hebden, A.; Wiencek, T.; Alderman, O. L.G.; Guthrie, M.; et al

    2014-11-21

    Uranium dioxide (UO2) is the major nuclear fuel component of fission power reactors. A key concern during severe accidents is the melting and leakage of radioactive UO2 as it corrodes through its zirconium cladding and steel containment. Yet, the very high temperatures (>3140 kelvin) and chemical reactivity of molten UO2 have prevented structural studies. In this work, we combine laser heating, sample levitation, and synchrotron x-rays to obtain pair distribution function measurements of hot solid and molten UO2. The hot solid shows a substantial increase in oxygen disorder around the lambda transition (2670 K) but negligible U-O coordination change. Onmore » melting, the average U-O coordination drops from 8 to 6.7 ± 0.5. Molecular dynamics models refined to this structure predict higher U-U mobility than 8-coordinated melts.« less

  17. Carbon dioxide research plan. A summary

    SciTech Connect

    Trivelpiece, Alvin W.; Koomanoff, F. A.; Suomi, Verner E.

    1983-11-01

    The Department of Energy is the lead federal agency for research related to atmospheric carbon dioxide. Its responsibility is to sponsor a program of relevant research, and to coordinate this research with that of others. As part of its responsibilities, the Department of Energy has prepared a research plan. The plan documented in this Summary delineated the logic, objectives, organization, background and current status of the research activities. The Summary Plan is based on research subplans in four specific areas: global carbon cycle, climate effects, vegetative response and indirect effects. These subplans have emanated from a series of national and international workshops, conferences, and from technical reports. The plans have been peer reviewed by experts in the relevant scientific fields. Their execution is being coordinated between the responsible federal and international government agencies and the involved scientific community.

  18. Layered solid sorbents for carbon dioxide capture

    DOEpatents

    Li, Bingyun; Jiang, Bingbing; Gray, McMahan L; Fauth, Daniel J; Pennline, Henry W; Richards, George A

    2014-11-18

    A solid sorbent for the capture and the transport of carbon dioxide gas is provided having at least one first layer of a positively charged material that is polyethylenimine or poly(allylamine hydrochloride), that captures at least a portion of the gas, and at least one second layer of a negatively charged material that is polystyrenesulfonate or poly(acryclic acid), that transports the gas, wherein the second layer of material is in juxtaposition to, attached to, or crosslinked with the first layer for forming at least one bilayer, and a solid substrate support having a porous surface, wherein one or more of the bilayers is/are deposited on the surface of and/or within the solid substrate. A method of preparing and using the solid sorbent is provided.

  19. Molten uranium dioxide structure and dynamics

    SciTech Connect

    Skinner, L. B.; Parise, J. B.; Benmore, C. J.; Weber, J. K.R.; Williamson, M. A.; Tamalonis, A.; Hebden, A.; Wiencek, T.; Alderman, O. L.G.; Guthrie, M.; Leibowitz, L.

    2014-11-21

    Uranium dioxide (UO2) is the major nuclear fuel component of fission power reactors. A key concern during severe accidents is the melting and leakage of radioactive UO2 as it corrodes through its zirconium cladding and steel containment. Yet, the very high temperatures (>3140 kelvin) and chemical reactivity of molten UO2 have prevented structural studies. In this work, we combine laser heating, sample levitation, and synchrotron x-rays to obtain pair distribution function measurements of hot solid and molten UO2. The hot solid shows a substantial increase in oxygen disorder around the lambda transition (2670 K) but negligible U-O coordination change. On melting, the average U-O coordination drops from 8 to 6.7 ± 0.5. Molecular dynamics models refined to this structure predict higher U-U mobility than 8-coordinated melts.

  20. Coiled tubing drilling with supercritical carbon dioxide

    DOEpatents

    Kolle , Jack J.

    2002-01-01

    A method for increasing the efficiency of drilling operations by using a drilling fluid material that exists as supercritical fluid or a dense gas at temperature and pressure conditions existing at a drill site. The material can be used to reduce mechanical drilling forces, to remove cuttings, or to jet erode a substrate. In one embodiment, carbon dioxide (CO.sub.2) is used as the material for drilling within wells in the earth, where the normal temperature and pressure conditions cause CO.sub.2 to exist as a supercritical fluid. Supercritical carbon dioxide (SC--CO.sub.2) is preferably used with coiled tube (CT) drilling equipment. The very low viscosity SC--CO.sub.2 provides efficient cooling of the drill head, and efficient cuttings removal. Further, the diffusivity of SC--CO.sub.2 within the pores of petroleum formations is significantly higher than that of water, making jet erosion using SC--CO.sub.2 much more effective than water jet erosion. SC--CO.sub.2 jets can be used to assist mechanical drilling, for erosion drilling, or for scale removal. A choke manifold at the well head or mud cap drilling equipment can be used to control the pressure within the borehole, to ensure that the temperature and pressure conditions necessary for CO.sub.2 to exist as either a supercritical fluid or a dense gas occur at the drill site. Spent CO.sub.2 can be vented to the atmosphere, collected for reuse, or directed into the formation to aid in the recovery of petroleum.

  1. Thermal analysis of a coaxial helium panel of a cryogenic vacuum pump for advanced divertor of DIII-D tokamak

    SciTech Connect

    Baxi, C.B.; Langhorn, A.; Schaubel, K.; Smith, J.

    1991-08-01

    It is planned to install a 50,000 1/s cryogenic pump for particle removal in the D3-D tokamak. A critical component of this cryogenic pump will be a helium panel which has to be maintained at a liquid helium temperature. The outer surface area of the helium panel has an area of 1 m{sup 2} and consists of a 2.5 cm diameter, 10 m long tube. From design considerations, a coaxial geometry is preferable since it requires a minimum number of welds. However, the coaxial geometry also results in a counter flow heat exchanger arrangement, where the outgoing warm fluid will exchange heat with incoming cold fluid. This is of concern since the helium panel must be cooled from liquid nitrogen temperature to liquid helium temperature in less than 5 minutes for successful operation of the cryogenic pump. In order to analyze the thermal performance of the coaxial helium panel, a finite difference computer model of the geometry was prepared. The governing equations took into account axial as well as radial conduction through the tube walls. The variation of thermal properties was modeled. The results of the analysis showed that although the coaxial geometry behaves like a counter flow heat exchanger, within the operating range of the cryogenic pump a rapid cooldown of the helium panel from liquid nitrogen temperature to the operating temperature is feasible. A prototypical experiment was also performed at General Atomics (GA) which verified the concept and the analysis. 4 refs., 8 figs.

  2. Terpolymerization of ethylene, sulfur dioxide and carbon monoxide

    DOEpatents

    Johnson, R.; Steinberg, M.

    This invention relates to high molecular weight terpolymer of ethylene, sulfur dioxide and carbon monoxide stable to 280/sup 0/C and containing as little as 36 mo1% ethylene and about 41 to 51 mo1% sulfur dioxide, and to the method of producing said terpolymer by irradiation of a liquid and gaseous mixture of ethylene, sulfur dioxide and carbon monoxide by means of Co-60 gamma rays or an electron beam, at a temperature of about 10 to 50/sup 0/C, and at a pressure of about 140 to 680 atmospheres, to initiate polymerization.

  3. Fact #948: October 24, 2016 Carbon Dioxide Emissions from Transportation

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Exceeded those from the Electric Power Sector for the First Time in 38 Years | Department of Energy 8: October 24, 2016 Carbon Dioxide Emissions from Transportation Exceeded those from the Electric Power Sector for the First Time in 38 Years Fact #948: October 24, 2016 Carbon Dioxide Emissions from Transportation Exceeded those from the Electric Power Sector for the First Time in 38 Years SUBSCRIBE to the Fact of the Week Beginning in 1978, carbon dioxide (CO2) emissions from the electric

  4. Estimated Carbon Dioxide Emissions in 2008: United States

    SciTech Connect

    Smith, C A; Simon, A J; Belles, R D

    2011-04-01

    Flow charts depicting carbon dioxide emissions in the United States have been constructed from publicly available data and estimates of state-level energy use patterns. Approximately 5,800 million metric tons of carbon dioxide were emitted throughout the United States for use in power production, residential, commercial, industrial, and transportation applications in 2008. Carbon dioxide is emitted from the use of three major energy resources: natural gas, coal, and petroleum. The flow patterns are represented in a compact 'visual atlas' of 52 state-level (all 50 states, the District of Columbia, and one national) carbon dioxide flow charts representing a comprehensive systems view of national CO{sub 2} emissions. Lawrence Livermore National Lab (LLNL) has published flow charts (also referred to as 'Sankey Diagrams') of important national commodities since the early 1970s. The most widely recognized of these charts is the U.S. energy flow chart (http://flowcharts.llnl.gov). LLNL has also published charts depicting carbon (or carbon dioxide potential) flow and water flow at the national level as well as energy, carbon, and water flows at the international, state, municipal, and organizational (i.e. United States Air Force) level. Flow charts are valuable as single-page references that contain quantitative data about resource, commodity, and byproduct flows in a graphical form that also convey structural information about the system that manages those flows. Data on carbon dioxide emissions from the energy sector are reported on a national level. Because carbon dioxide emissions are not reported for individual states, the carbon dioxide emissions are estimated using published energy use information. Data on energy use is compiled by the U.S. Department of Energy's Energy Information Administration (U.S. EIA) in the State Energy Data System (SEDS). SEDS is updated annually and reports data from 2 years prior to the year of the update. SEDS contains data on primary

  5. Terpolymerization of ethylene, sulfur dioxide and carbon monoxide

    DOEpatents

    Johnson, Richard; Steinberg, Meyer

    1981-01-01

    This invention relates to a high molecular weight terpolymer of ethylene, sulfur dioxide and carbon monoxide stable to 280.degree. C. and containing as little as 36 mol % ethylene and about 41-51 mol % sulfur dioxide; and to the method of producing said terpolymer by irradiation of a liquid and gaseous mixture of ethylene, sulfur dioxide and carbon monoxide by means of Co-60 gamma rays or an electron beam, at a temperature of about 10.degree.-50.degree. C., and at a pressure of about 140 to 680 atmospheres, to initiate polymerization.

  6. DOE Announces $80 Million Investment to Build Supercritical Carbon Dioxide

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Pilot Plant Test Facility | Department of Energy Announces $80 Million Investment to Build Supercritical Carbon Dioxide Pilot Plant Test Facility DOE Announces $80 Million Investment to Build Supercritical Carbon Dioxide Pilot Plant Test Facility October 17, 2016 - 11:39am Addthis WASHINGTON - The U.S. Department of Energy (DOE) is awarding up to $80 million for a six-year project to design, build, and operate a 10-MWe (megawatts electrical) supercritical carbon dioxide (sCO2) pilot plant

  7. Supercritical Carbon Dioxide Turbo-Expander and Heat Exchangers |

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Department of Energy Supercritical Carbon Dioxide Turbo-Expander and Heat Exchangers Supercritical Carbon Dioxide Turbo-Expander and Heat Exchangers This fact sheet describes a supercritical carbon dioxide turbo-expander and heat exchangers project awarded under the DOE's 2012 SunShot Concentrating Solar Power R&D award program. The team, led by the Southwest Research Institute, is working to develop a megawatt-scale s-CO2 hot-gas turbo-expander optimized for the highly transient solar

  8. Void structure and density change of vanadium-base alloys irradiated in the dynamic helium charging experiment

    SciTech Connect

    Chung, H.M.; Nowicki, L.; Gazda, J.

    1995-04-01

    The objective of this work is to determine void structure, distribution, and density changes of several promising vanadium-base alloys irradiated in the Dynamic Helium Charging Experiment (DHCE). Combined effects of dynamically charged helium and neutron damage on density change, void distribution, and microstructural evolution of V-4Cr-4Ti alloy have been determined after irradiation to 18-31 dpa at 425-600{degree}C in the DHCE, and the results compared with those from a non-DHCE in which helium generation was negligible.

  9. Curbing the greenhouse effect by carbon dioxide adsorption with zeolite 13X

    SciTech Connect

    Konduru, N.; Lindner, P.; Assaf-Anad, N.M.

    2007-12-15

    The removal of carbon dioxide (CO{sub 2}) from industrial emissions has become essential in the fight against climate change. In this study, we employed Zeolite 13X for the capture and recovery of CO{sub 2} in a flow through system where the adsorbent was subjected to five adsorption-desorption cycles. The influent stream contained 1.5% CO{sub 2} at standard conditions. The adsorbent bed was 1 in. in length and 1 in.3/8 in dia., and was packed with 10 g of the zeolite. Temperature swing adsorption (TSA) was employed as the regeneration method through heating to approximately 135{sup o}C with helium as the purge gas. The adsorbent capacity at 90% saturation was found to decrease from 78 to 60g CO{sub 2}/kg{sub Zeolite13X} after the fifth cycle. The CO{sub 2} capture ratio or the mass of CO{sub 2} adsorbed to the total mass that entered the system decreased from 63% to only 61% after the fifth cycle. The CO{sub 2} recovery efficiency ranged from 82 to 93% during desorption, and the CO{sub 2} relative recovery, i.e., CO{sub 2} desorbed for the nth cycle to CO{sub 2} adsorbed for the first cycle, ranged from 88 to 68%. The service life of the adsorbent was determined to be equal to eleven cycles at a useful capacity of 40g CO{sub 2}/kg{sub Zeolite13X}.

  10. Short-Term Energy Outlook Model Documentation: Carbon Dioxide (CO2) Emissions Model

    Reports and Publications

    2009-01-01

    Description of the procedures for estimating carbon dioxide emissions in the Short-Term Energy Outlook

  11. Carbon Dioxide-Water Emulsions for Enhanced Oil Recovery and Permanent Sequestration of Carbon Dioxide

    SciTech Connect

    Ryan, David; Golomb, Dan; Shi, Guang; Shih, Cherry; Lewczuk, Rob; Miksch, Joshua; Manmode, Rahul; Mulagapati, Srihariraju; Malepati, Chetankurmar

    2011-09-30

    This project involves the use of an innovative new invention Particle Stabilized Emulsions (PSEs) of Carbon Dioxide-in-Water and Water-in-Carbon Dioxide for Enhanced Oil Recovery (EOR) and Permanent Sequestration of Carbon Dioxide. The EOR emulsion would be injected into a semi-depleted oil reservoir such as Dover 33 in Otsego County, Michigan. It is expected that the emulsion would dislocate the stranded heavy crude oil from the rock granule surfaces, reduce its viscosity, and increase its mobility. The advancing emulsion front should provide viscosity control which drives the reduced-viscosity oil toward the production wells. The make-up of the emulsion would be subsequently changed so it interacts with the surrounding rock minerals in order to enhance mineralization, thereby providing permanent sequestration of the injected CO{sub 2}. In Phase 1 of the project, the following tasks were accomplished: 1. Perform laboratory scale (mL/min) refinements on existing procedures for producing liquid carbon dioxide-in-water (C/W) and water-in-liquid carbon dioxide (W/C) emulsion stabilized by hydrophilic and hydrophobic fine particles, respectively, using a Kenics-type static mixer. 2. Design and cost evaluate scaled up (gal/min) C/W and W/C emulsification systems to be deployed in Phase 2 at the Otsego County semi-depleted oil field. 3. Design the modifications necessary to the present CO{sub 2} flooding system at Otsego County for emulsion injection. 4. Design monitoring and verification systems to be deployed in Phase 2 for measuring potential leakage of CO{sub 2} after emulsion injection. 5. Design production protocol to assess enhanced oil recovery with emulsion injection compared to present recovery with neat CO{sub 2} flooding. 6. Obtain Federal and State permits for emulsion injection. Initial research focused on creating particle stabilized emulsions with the smallest possible globule size so that the emulsion can penetrate even low-permeability crude

  12. WARM BREEZE FROM THE STARBOARD BOW: A NEW POPULATION OF NEUTRAL HELIUM IN THE HELIOSPHERE

    SciTech Connect

    Kubiak, M. A.; Bzowski, M.; Sokół, J. M.; Swaczyna, P.; Grzedzielski, S.; Alexashov, D. B.; Izmodenov, V. V.; Möbius, E.; Leonard, T.; Fuselier, S. A.; McComas, D. J.; Wurz, P.

    2014-08-01

    We investigate the signals from neutral helium atoms observed in situ from Earth orbit in 2010 by the Interstellar Boundary Explorer (IBEX). The full helium signal observed during the 2010 observation season can be explained as a superposition of pristine neutral interstellar He gas and an additional population of neutral helium that we call the Warm Breeze. The Warm Breeze is approximately 2 times slower and 2.5 times warmer than the primary interstellar He population, and its density in front of the heliosphere is ∼7% that of the neutral interstellar helium. The inflow direction of the Warm Breeze differs by ∼19° from the inflow direction of interstellar gas. The Warm Breeze seems to be a long-term, perhaps permanent feature of the heliospheric environment. It has not been detected earlier because it is strongly ionized inside the heliosphere. This effect brings it below the threshold of detection via pickup ion and heliospheric backscatter glow observations, as well as by the direct sampling of GAS/Ulysses. We discuss possible sources for the Warm Breeze, including (1) the secondary population of interstellar helium, created via charge exchange and perhaps elastic scattering of neutral interstellar He atoms on interstellar He{sup +} ions in the outer heliosheath, or (2) a gust of interstellar He originating from a hypothetic wave train in the Local Interstellar Cloud. A secondary population is expected from models, but the characteristics of the Warm Breeze do not fully conform to modeling results. If, nevertheless, this is the explanation, IBEX-Lo observations of the Warm Breeze provide key insights into the physical state of plasma in the outer heliosheath. If the second hypothesis is true, the source is likely to be located within a few thousand AU from the Sun, which is the propagation range of possible gusts of interstellar neutral helium with the Warm Breeze characteristics against dissipation via elastic scattering in the Local Cloud. Whatever the

  13. Slurried solid media for simultaneous water purification and carbon dioxide removal from gas mixtures

    DOEpatents

    Aines, Roger D.; Bourcier, William L.; Viani, Brian

    2013-01-29

    A slurried solid media for simultaneous water purification and carbon dioxide removal from gas mixtures includes the steps of dissolving the gas mixture and carbon dioxide in water providing a gas, carbon dioxide, water mixture; adding a porous solid media to the gas, carbon dioxide, water mixture forming a slurry of gas, carbon dioxide, water, and porous solid media; heating the slurry of gas, carbon dioxide, water, and porous solid media producing steam; and cooling the steam to produce purified water and carbon dioxide.

  14. Membranes for separation of carbon dioxide

    DOEpatents

    Ku, Anthony Yu-Chung; Ruud, James Anthony; Ramaswamy, Vidya; Willson, Patrick Daniel; Gao, Yan

    2011-03-01

    Methods for separating carbon dioxide from a fluid stream at a temperature higher than about 200.degree. C. with selectivity higher than Knudsen diffusion selectivity include contacting a porous membrane with the fluid stream to preferentially transport carbon dioxide. The porous membrane includes a porous support and a continuous porous separation layer disposed on a surface of the porous support and extending between the fluid stream and the porous support layer. The porous support comprises alumina, silica, zirconia, stabilized zirconia, stainless steel, titanium, nickel-based alloys, aluminum-based alloys, zirconium-based alloys or a combination thereof. Median pore size of the porous separation layer is less than about 10 nm, and the porous separation layer comprises titania, MgO, CaO, SrO, BaO, La.sub.2O.sub.3, CeO.sub.2, HfO.sub.2, Y.sub.2O.sub.3, VO.sub.z, NbO.sub.z, TaO.sub.z, ATiO.sub.3, AZrO.sub.3, AAl.sub.2O.sub.4, A.sup.1FeO.sub.3, A.sup.1MnO.sub.3, A.sup.1CoO.sub.3, A.sup.1NiO.sub.3, A.sup.2HfO.sub.3, A.sup.3 CeO.sub.3, Li.sub.2ZrO.sub.3, Li.sub.2SiO.sub.3, Li.sub.2TiO.sub.3, Li.sub.2HfO.sub.3, A.sup.4N.sup.1.sub.yO.sub.z, Y.sub.xN.sup.1.sub.yO.sub.z, La.sub.xN.sup.1.sub.yO.sub.z, HfN.sup.2.sub.yO.sub.z, or a combination thereof; wherein A is La, Mg, Ca, Sr or Ba; A.sup.1 is La, Ca, Sr or Ba; A.sup.2 is Ca, Sr or Ba; A.sup.3 is Sr or Ba; A.sup.4 is Mg, Ca, Sr, Ba, Ti or Zr; N.sup.1 is V, Nb, Ta, Cr, Mo, W, Mn, Si or Ge; N.sup.2 is V, Mo, W or Si; x is 1 or 2; y ranges from 1 to 3; and z ranges from 2 to 7.

  15. A versatile metal-organic framework for carbon dioxide capture...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    versatile metal-organic framework for carbon dioxide capture and cooperative catalysis Previous Next List Jinhee Park, Jian-Rong Li, Ying-Pin Chen, Jiamei Yu, Andrey A. Yakovenko, ...

  16. Recent advances in carbon dioxide capture with metal-organic...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Recent advances in carbon dioxide capture with metal-organic frameworks Previous Next List ... Great progress in MOF materials for CO2 capture has been made in the past and reviewed ...

  17. Carbon dioxide capture-related gas adsorption and separation...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Carbon dioxide capture-related gas adsorption and separation in metal-organic frameworks Previous Next List Jian-Rong Li, Yuguang Ma, M. Colin McCarthy, Julian Sculley, Jiamei Yu,...

  18. CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS

    SciTech Connect

    David A. Green; Brian S. Turk; Jeffrey W. Portzer; Thomas Nelson; Raghubir P. Gupta

    2005-01-01

    This report describes research conducted between October 1, 2004 and December 31, 2004 on the use of dry regenerable sorbents for removal of carbon dioxide from flue gas. Two supported sorbents were tested in a bench scale fluidized bed reactor system. The sorbents were prepared by impregnation of sodium carbonate on to an inert support at a commercial catalyst manufacturing facility. One sorbent, tested through five cycles of carbon dioxide sorption in an atmosphere of 3% water vapor and 0.8 to 3% carbon dioxide showed consistent reactivity with sodium carbonate utilization of 7 to 14%. A second, similarly prepared material, showed comparable reactivity in one cycle of testing. Batches of 5 other materials were prepared in laboratory scale quantities (primarily by spray drying). These materials generally have significantly greater surface areas than calcined sodium bicarbonate. Small scale testing showed no significant adsorption of mercury on representative carbon dioxide sorbent materials under expected flue gas conditions.

  19. Carbon Dioxide Capture in Metal-Organic Frameworks | Center for...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Carbon Dioxide Capture in Metal-Organic Frameworks Previous Next List Kenji Sumida , David L. Rogow , Jarad A. Mason , Thomas M. McDonald , Eric D. Bloch , Zoey R. Herm , Tae-Hyun...

  20. Fact #898: November 9, 2015 World Carbon Dioxide Emissions, 1990...

    Energy.gov [DOE] (indexed site)

    World Carbon Dioxide Emissions, 1990-2012 Year United States Rest of North America Central & South America Europe Eurasia Middle East Africa India China Rest of Asia & Oceania 1990 ...

  1. Short-Term Energy Carbon Dioxide Emissions Forecasts August 2009

    Reports and Publications

    2009-01-01

    Supplement to the Short-Term Energy Outlook. Short-term projections for U.S. carbon dioxide emissions of the three fossil fuels: coal, natural gas, and petroleum.

  2. U.S. Energy-Related Carbon Dioxide Emissions, 2013

    Annual Energy Outlook

    Energy-Related Carbon Dioxide Emissions, 2013 October 2014 Independent Statistics & Analysis www.eia.gov U.S. Department of Energy Washington, DC 20585 October 2014 U.S. Energy...

  3. Carbon Dioxide Capture: Prospects for New Materials | Center...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Carbon Dioxide Capture: Prospects for New Materials Previous Next List D. M. D'Alessandro, B. Smit, and J. R. Long, Angew. Chem.-Int. Edit. 49 (35), 6058 (2010) DOI: 10.1002...

  4. Carbon Dioxide Emissions From Vegetation-Kill Zones Around The...

    OpenEI (Open Energy Information) [EERE & EIA]

    Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Carbon Dioxide Emissions From Vegetation-Kill Zones Around The Resurgent Dome Of Long Valley...

  5. Table 21. Total Energy Related Carbon Dioxide Emissions, Projected...

    Energy Information Administration (EIA) (indexed site)

    Total Energy Related Carbon Dioxide Emissions, Projected vs. Actual Projected (million metric tons) 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 ...

  6. "Table 21. Total Energy Related Carbon Dioxide Emissions, Projected...

    Energy Information Administration (EIA) (indexed site)

    Total Energy Related Carbon Dioxide Emissions, Projected vs. Actual" "Projected" " (million metric tons)" ,1993,1994,1995,1996,1997,1998,1999,2000,2001,2002,2003,2004,2005,2006,200...

  7. Formation of rare earth carbonates using supercritical carbon dioxide

    DOEpatents

    Fernando, Quintus; Yanagihara, Naohisa; Dyke, James T.; Vemulapalli, Krishna

    1991-09-03

    The invention relates to a process for the rapid, high yield conversion of select rare earth oxides or hydroxides, to their corresponding carbonates by contact with supercritical carbon dioxide.

  8. Copper clusters capture and convert carbon dioxide to make fuel...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    The benefit of enhanced binding is that the new catalyst requires lower pressure and less energy to produce the same amount of methanol. Carbon dioxide emissions are an ongoing...

  9. Project Profile: 10-Megawatt Supercritical Carbon Dioxide Turbine

    Energy.gov [DOE]

    The National Renewable Energy Laboratory (NREL) and its partners, under the 2012 SunShot Concentrating Solar Power (CSP) R&D funding opportunity announcement (FOA), aim to demonstrate a multi-megawatt power cycle using supercritical carbon dioxide (s-CO2) as the working fluid. The use of carbon dioxide instead of steam allows higher power-cycle efficiency and cycle components that are more compact.

  10. Tethered catalysts for the hydration of carbon dioxide

    DOEpatents

    Valdez, Carlos A; Satcher, Jr., Joe H; Aines, Roger D; Wong, Sergio E; Baker, Sarah E; Lightstone, Felice C; Stolaroff, Joshuah K

    2014-11-04

    A system is provided that substantially increases the efficiency of CO.sub.2 capture and removal by positioning a catalyst within an optimal distance from the air-liquid interface. The catalyst is positioned within the layer determined to be the highest concentration of carbon dioxide. A hydrophobic tether is attached to the catalyst and the hydrophobic tether modulates the position of the catalyst within the liquid layer containing the highest concentration of carbon dioxide.

  11. New Texas Oil Project Will Help Keep Carbon Dioxide Underground |

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Department of Energy Texas Oil Project Will Help Keep Carbon Dioxide Underground New Texas Oil Project Will Help Keep Carbon Dioxide Underground February 5, 2013 - 12:05pm Addthis The Air Products and Chemicals hydrogen production facilities in Port Arthur, Texas, is funded by the Energy Department through the 2009 Recovery Act. It is managed by the Office of Fossil Energy’s National Energy Technology Laboratory. | Photo credit Air Products and Chemicals hydrogen production facilities.

  12. Estimates of State Energy-Related Carbon Dioxide Emissions

    Energy Information Administration (EIA) (indexed site)

    November 2016 Estimates of State Energy-Related Carbon Dioxide Emissions Because energy-related carbon dioxide (CO2) constitutes over 80% of total emissions, the state energy- related CO2 emission levels provide a good indicator of the relative contribution of individual states to total greenhouse gas emissions. The U.S. Energy Information Administration (EIA) emissions estimates at the state level for energy-related CO2 are based on data contained in the State Energy Data System (SEDS). 1 The

  13. First Direct Observation of Carbon Dioxide's Increasing Greenhouse Effect

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    at Earth's Surface First Direct Observation of Carbon Dioxide's Increasing Greenhouse Effect at Earth's Surface First Direct Observation of Carbon Dioxide's Increasing Greenhouse Effect at Earth's Surface Researchers Link Rising CO₂ Levels from Fossil Fuels to Radiative Forcing February 25, 2015 Contact: Dan Krotz, dakrotz@lbl.gov, 510-486-4019 ARM Alaska Caption: The scientists used incredibly precise spectroscopic instruments at two sites operated by the Department of Energy's

  14. Using supercritical carbon dioxide as a fracturing fluid

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Using supercritical carbon dioxide as a fracturing fluid Using supercritical carbon dioxide as a fracturing fluid The Laboratory team used a combination of experiments and modeling for the investigation. June 25, 2015 Simulation of a selection of the particle trajectories toward the well. Simulation of a selection of the particle trajectories toward the well. Communications Office (505) 667-7000 The Laboratory research is part of an ongoing project to make the necessary measurements and develop

  15. Evidence for impact ionization in vanadium dioxide (Journal Article) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Evidence for impact ionization in vanadium dioxide Citation Details In-Document Search This content will become publicly available on October 17, 2017 Title: Evidence for impact ionization in vanadium dioxide Authors: Holleman, Joshua ; Bishop, Michael M. ; Garcia, Carlos ; Vellore Winfred, J. S. R. ; Lee, Shinbuhm ; Lee, Ho Nyung ; Beekman, Christianne ; Manousakis, Efstratios ; McGill, Stephen A. Publication Date: 2016-10-17 OSTI Identifier: 1329101 Type: Publisher's

  16. Recycling Carbon Dioxide to Make Plastics | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Recycling Carbon Dioxide to Make Plastics Recycling Carbon Dioxide to Make Plastics May 20, 2013 - 1:31pm Addthis Novomer’s thermoplastic pellets incorporate waste CO2 into a variety of consumer products. Novomer's thermoplastic pellets incorporate waste CO2 into a variety of consumer products. Why is this important? By using CO2 that would otherwise be emitted to the atmosphere, the process has the potential to cut greenhouse gas emissions while simultaneously reducing petroleum

  17. Geologic Carbon Dioxide Storage Field Projects Supported by DOE's

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Sequestration Program | Department of Energy Geologic Carbon Dioxide Storage Field Projects Supported by DOE's Sequestration Program Geologic Carbon Dioxide Storage Field Projects Supported by DOE's Sequestration Program Background: The U.S. DOE's Sequestration Program began with a small appropriation of $1M in 1997 and has grown to be the largest most comprehensive CCS R&D program in the world. The U.S. DOE's sequestration program has supported a number of projects implementing CO2

  18. Carbon Ion Pump for Carbon Dioxide Removal - Energy Innovation Portal

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Industrial Technologies Industrial Technologies Find More Like This Return to Search Carbon Ion Pump for Carbon Dioxide Removal Lawrence Livermore National Laboratory Contact LLNL About This Technology Technology Marketing Summary The limitation to reducing greenhouse gases in the atmosphere is the expense of stripping carbon dioxide from other combustion gases. Without a cost-effective means of accomplishing this, hydrocarbon resources cannot be used freely. A few power plants currently remove

  19. The effect of helium from tritium decay on the gas-solid equilibrium constant for La-Ni-Al tritides

    SciTech Connect

    Walters, R.T.

    1988-01-01

    Change in the equilibrium vapor pressure over LaNi/sub 4.25/ Al/sub 0.75/ tritide with helium in-growth has been observed for helium concentrations up to 10,000 appm. The change is a decrease in pressure from about 500 torr to 90 torr at 80/degree/C. This decrease is believed to be associated with a crystal lattice expansion due to helium, and is similar to the plateau pressure decrease as function of aluminum concentration for the family of LaNi/sub 5-x/Al/sub x/ alloys with O < x < 1. Subsequent tritium cycling recovers the plateau pressure. These data suggest that helium has very short range diffusion for the time of these observations. 18 refs., 4 figs., 2 tabs.

  20. Nitrogen dioxide and respiratory illnesses in infants

    SciTech Connect

    Samet, J.M.; Lambert, W.E.; Skipper, B.J.; Cushing, A.H.; Hunt, W.C.; Young, S.A.; McLaren, L.C.; Schwab, M.; Spengler, J.D. )

    1993-11-01

    Nitrogen dioxide is an oxidant gas that contaminates outdoor air and indoor air in homes with unvented gas appliances. A prospective cohort study was carried out to test the hypothesis that residential exposure to NO2 increases incidence and severity of respiratory illnesses during the first 18 months of life. A cohort of 1,205 healthy infants from homes without smokers was enrolled. The daily occurrence of respiratory symptoms and illnesses was reported by the mothers every 2 wk. Illnesses with wheezing or wet cough were classified as lower respiratory tract. Indoor NO2 concentrations were serially measured with passive samplers place in the subjects' bedrooms. In stratified analyses, illness incidence rates did not consistently increase with exposure to NO2 or stove type. In multivariate analyses that adjusted for potential confounding factors, odds ratios were not significantly elevated for current or lagged NO2 exposures, or stove type. Illness duration, a measure of illness severity, was not associated with NO2 exposure. The findings can be extended to homes with gas stoves in regions of the United States where the outdoor air is not heavily polluted by NO2.

  1. Use of molecular modeling to determine the interaction and competition of gases within coal for carbon dioxide sequestration

    SciTech Connect

    Jeffrey D. Evanseck; Jeffry D. Madura; Jonathan P. Mathews

    2006-04-21

    Molecular modeling was employed to both visualize and probe our understanding of carbon dioxide sequestration within a bituminous coal. A large-scale (>20,000 atoms) 3D molecular representation of Pocahontas No. 3 coal was generated. This model was constructed based on a the review data of Stock and Muntean, oxidation and decarboxylation data for aromatic clustersize frequency of Stock and Obeng, and the combination of Laser Desorption Mass Spectrometry data with HRTEM, enabled the inclusion of a molecular weight distribution. The model contains 21,931 atoms, with a molecular mass of 174,873 amu, and an average molecular weight of 714 amu, with 201 structural components. The structure was evaluated based on several characteristics to ensure a reasonable constitution (chemical and physical representation). The helium density of Pocahontas No. 3 coal is 1.34 g/cm{sup 3} (dmmf) and the model was 1.27 g/cm{sup 3}. The structure is microporous, with a pore volume comprising 34% of the volume as expected for a coal of this rank. The representation was used to visualize CO{sub 2}, and CH{sub 4} capacity, and the role of moisture in swelling and CO{sub 2}, and CH{sub 4} capacity reduction. Inclusion of 0.68% moisture by mass (ash-free) enabled the model to swell by 1.2% (volume). Inclusion of CO{sub 2} enabled volumetric swelling of 4%.

  2. Supply and Demand of Helium-3| U.S. DOE Office of Science (SC)

    Office of Science (SC)

    Supply and Demand of Helium-3 Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Funding Opportunities Nuclear Science Advisory Committee (NSAC) Community Resources Contact Information Nuclear Physics U.S. Department of Energy SC-26/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3613 F: (301) 903-3833 E: Email Us More Information » Isotope Development & Production for Research and Applications (IDPRA) Supply and Demand

  3. Radiation and gas conduction heat transport across a helium dewer multilayer insulation system

    SciTech Connect

    Green, M.A.

    1995-02-01

    This report describes a method for calculating mixed heat transfer through the multilayer insulation used to insulated a 4K liquid helium cryostat. The method described permits one to estimate the insulation potential for a multilayer insulation system from first principles. The heat transfer regimes included are: radiation, conduction by free molecule gas conduction, and conduction through continuum gas conduction. Heat transfer in the transition region between the two gas conduction regimes is also included.

  4. Final Technical Report for the Neutron Detection without Helium-3 Project

    SciTech Connect

    Ely, James H.; Bliss, Mary; Kouzes, Richard T.; Lintereur, Azaree T.; Robinson, Sean M.; Siciliano, Edward R.; Swinhoe, Martyn T.; Woodring, Mitchell L.

    2013-11-01

    This report details the results of the research and development work accomplished for the ‘Neutron Detection without Helium-3’ project conducted during the 2011-2013 fiscal years. The primary focus of the project was to investigate commercially available technologies that might be used in safeguards applications in the relatively near term. Other technologies that are being developed may be more applicable in the future, but were outside the scope of this study.

  5. The role of correlation in the ground state energy of confined helium atom

    SciTech Connect

    Aquino, N.

    2014-01-14

    We analyze the ground state energy of helium atom confined by spherical impenetrable walls, and the role of the correlation energy in the total energy. The confinement of an atom in a cavity is one way in which we can model the effect of the external pressure on an atom. The calculations of energy of the system are carried out by the variational method. We find that the correlation energy remains almost constant for a range values of size of the boxes analyzed.

  6. Modeling and Simulation Optimization and Feasibility Studies for the Neutron Detection without Helium-3 Project

    SciTech Connect

    Ely, James H.; Siciliano, Edward R.; Swinhoe, Martyn T.; Lintereur, Azaree T.

    2013-01-01

    This report details the results of the modeling and simulation work accomplished for the ‘Neutron Detection without Helium-3’ project during the 2011 and 2012 fiscal years. The primary focus of the project is to investigate commercially available technologies that might be used in safeguards applications in the relatively near term. Other technologies that are being developed may be more applicable in the future, but are outside the scope of this study.

  7. Improvements of fuel failure detection in boiling water reactors using helium measurements

    SciTech Connect

    Larsson, I.; Sihver, L.; Grundin, A.; Helmersson, J. O.

    2012-07-01

    To certify a continuous and safe operation of a boiling water reactor, careful surveillance of fuel integrity is of high importance. The detection of fuel failures can be performed by off-line gamma spectroscopy of off-gas samples and/or by on-line nuclide specific monitoring of gamma emitting noble gases. To establish the location of a leaking fuel rod, power suppression testing can be used. The accuracy of power suppression testing is dependent on the information of the delay time and the spreading of the released fission gases through the systems before reaching the sampling point. This paper presents a method to improve the accuracy of power suppression testing by determining the delay time and gas spreading profile. To estimate the delay time and examine the spreading of the gas in case of a fuel failure, helium was injected in the feed water system at Forsmark 3 nuclear power plant. The measurements were performed by using a helium detector system based on a mass spectrometer installed in the off-gas system. The helium detection system and the results of the experiment are presented in this paper. (authors)

  8. Design guidelines for avoiding thermo-acoustic oscillations in helium piping systems

    SciTech Connect

    Gupta, Prabhat Kumar; Rabehl, Roger

    2015-04-02

    Thermo-acoustic oscillations are a commonly observed phenomenon in helium cryogenic systems, especially in tubes connecting hot and cold areas. The open ends of these tubes are connected to the lower temperature (typically at 4.5 K), and the closed ends of these tubes are connected to the high temperature (300 K). Cryogenic instrumentation installations provide ideal conditions for these oscillations to occur due to the steep temperature gradient along the tubing. These oscillations create errors in measurements as well as an undesirable heat load to the system. The work presented here develops engineering guidelines to design oscillation-free helium piping. This work also studies the effect of different piping inserts and shows how the proper geometrical combinations have to be chosen to avoid thermo-acoustic oscillations. The effect of an 80 K intercept is also studied and shows that thermo-oscillations can be dampened by placing the intercept at an appropriate location. As a result, the design of helium piping based on the present work is also verified with the experimental results available in open literature.

  9. Comparison between a propane-air combustion front and a helium-air simulated combustion front

    SciTech Connect

    Barraclough, S.

    1983-12-01

    Turbulent combustion experiments were performed in a right cylindrical combustion bomb using a premixed propane-air gaseous fuel. The initial conditions inside the combustion chamber were three psig and room temperature. Prior to spark firing, the turbulence intensity inside the combustion chamber was measured and could be varied over a ten fold range. The effect of initial turbulence intensity on turbulent flame propagation was investigated. Two regimes of turbulent combustion were identified, which is in agreement with a previous investigator's results. One of them, a ''transition regime'' occurs when the turbulence intensity is approximately twice the laminar flame speed. Within the transition regime, the turbulent burning speed is linearly proportional to initial turbulence intensity and independent of laminar flame speed and turbulence length scale. A high pressure helium front was injected into the combustion chamber to simulate the combustion front. Since the helium front is isothermal, hot-wire anemometry can be used to quantify the change in turbulence intensity ahead of the propagating front. The helium front was found to have different characteristics than the combustion front.

  10. A novel scheme to handle highly pulsed loads with a standard helium refrigerator

    SciTech Connect

    Slack, D.S.

    1993-06-30

    Helium refrigerator performance degrades rapidly when it has to handle a varying or pulsed heat load. A novel scheme is presented to handle highly pulsed 4.5 K cryogenic loads with a standard helium refrigerator by isolating it from these pulses. The scheme uses a relatively simple arrangement of control valves, heat exchangers, and a storage dewar. Applications include pulsed tokamak machines such as TPX (Tokamak Physics Experiment) and ITER (International Thermonuclear Experimental Reactor). For example, the TPX (currently in the conceptual design phase in a DoE contract) requires an average 4.5 K refrigerator capacity of about 10 kW; however, pulsed loads caused by eddy current and nuclear heating will exceed 100 kW. The scheme presented here provides a method for handling these pulsed loads. Because of the simple and proven nature of the components involved and the thermodynamic properties of the helium, the system could be implemented for projects such as TPX or ITER with little or no development.

  11. Benchmarking density functionals for hydrogen-helium mixtures with quantum Monte Carlo: Energetics, pressures, and forces

    DOE PAGES [OSTI]

    Clay, Raymond C.; Holzmann, Markus; Ceperley, David M.; Morales, Maguel A.

    2016-01-19

    An accurate understanding of the phase diagram of dense hydrogen and helium mixtures is a crucial component in the construction of accurate models of Jupiter, Saturn, and Jovian extrasolar planets. Though DFT based rst principles methods have the potential to provide the accuracy and computational e ciency required for this task, recent benchmarking in hydrogen has shown that achieving this accuracy requires a judicious choice of functional, and a quanti cation of the errors introduced. In this work, we present a quantum Monte Carlo based benchmarking study of a wide range of density functionals for use in hydrogen-helium mixtures atmore » thermodynamic conditions relevant for Jovian planets. Not only do we continue our program of benchmarking energetics and pressures, but we deploy QMC based force estimators and use them to gain insights into how well the local liquid structure is captured by di erent density functionals. We nd that TPSS, BLYP and vdW-DF are the most accurate functionals by most metrics, and that the enthalpy, energy, and pressure errors are very well behaved as a function of helium concentration. Beyond this, we highlight and analyze the major error trends and relative di erences exhibited by the major classes of functionals, and estimate the magnitudes of these e ects when possible.« less

  12. Design guidelines for avoiding thermo-acoustic oscillations in helium piping systems

    DOE PAGES [OSTI]

    Gupta, Prabhat Kumar; Rabehl, Roger

    2015-04-02

    Thermo-acoustic oscillations are a commonly observed phenomenon in helium cryogenic systems, especially in tubes connecting hot and cold areas. The open ends of these tubes are connected to the lower temperature (typically at 4.5 K), and the closed ends of these tubes are connected to the high temperature (300 K). Cryogenic instrumentation installations provide ideal conditions for these oscillations to occur due to the steep temperature gradient along the tubing. These oscillations create errors in measurements as well as an undesirable heat load to the system. The work presented here develops engineering guidelines to design oscillation-free helium piping. This workmore » also studies the effect of different piping inserts and shows how the proper geometrical combinations have to be chosen to avoid thermo-acoustic oscillations. The effect of an 80 K intercept is also studied and shows that thermo-oscillations can be dampened by placing the intercept at an appropriate location. As a result, the design of helium piping based on the present work is also verified with the experimental results available in open literature.« less

  13. Investigation of helium ion production in constricted direct current plasma ion source with layered-glows

    SciTech Connect

    Lee, Yuna; Chung, Kyoung-Jae; Park, Yeong-Shin; Hwang, Y. S.; Center for Advance Research in Fusion Reactor Engineering, Seoul National University, Seoul 151-744

    2014-02-15

    Generation of helium ions is experimentally investigated with a constricted direct current (DC) plasma ion source operated at layered-glow mode, in which electrons could be accelerated through multiple potential structures so as to generate helium ions including He{sup 2+} by successive ionization collisions in front of an extraction aperture. The helium discharge is sustained with the formation of a couple of stable layers and the plasma ball with high density is created near the extraction aperture at the operational pressure down to 0.6 Torr with concave cathodes. The ion beam current extracted with an extraction voltage of 5 kV is observed to be proportional to the discharge current and inversely proportional to the operating pressure, showing high current density of 130 mA/cm{sup 2} and power density of 0.52 mA/cm{sup 2}/W. He{sup 2+} ions, which were predicted to be able to exist due to multiple-layer potential structure, are not observed. Simple calculation on production of He{sup 2+} ions inside the plasma ball reveals that reduced operating pressure and increased cathode area will help to generate He{sup 2+} ions with the layered-glow DC discharge.

  14. A MEASUREMENT OF THE ADIABATIC COOLING INDEX FOR INTERSTELLAR HELIUM PICKUP IONS IN THE INNER HELIOSPHERE

    SciTech Connect

    Saul, Lukas; Wurz, Peter; Kallenbach, Reinald

    2009-09-20

    Interstellar neutral gas enters the inner heliosphere where it is ionized and becomes the pickup ion population of the solar wind. It is often assumed that this population will subsequently cool adiabatically, like an expanding ideal gas due, to the divergent flow of the solar wind. Here, we report the first independent measure of the effective adiabatic cooling index in the inner heliosphere from SOHO CELIAS measurements of singly charged helium taken during times of perpendicular interplanetary magnetic field. We use a simple adiabatic transport model of interstellar pickup helium ions, valid for the upwind region of the inner heliosphere. The time averaged velocity spectrum of helium pickup ions measured by CELIAS/CTOF is fit to this model with a single free parameter which indicates an effective cooling rate with a power-law index of gamma = 1.35 +- 0.2. While this average is consistent with the 'ideal-gas' assumption of gamma = 1.5, the analysis indicates that such an assumption will not apply in general, and that due to observational constraints further measurements are necessary to constrain the cooling process. Implications are discussed for understanding the transport processes in the inner heliosphere and improving this measurement technique.

  15. Design guidelines for avoiding thermo-acoustic oscillations in helium piping systems

    DOE PAGES [OSTI]

    Gupta, Prabhat Kumar; Rabehl, Roger

    2015-04-02

    Thermo-acoustic oscillations are a commonly observed phenomenon in helium cryogenic systems, especially in tubes connecting hot and cold areas. The open ends of these tubes are connected to the lower temperature (typically at 4.5 K), and the closed ends of these tubes are connected to the high temperature (300 K). Cryogenic instrumentation installations provide ideal conditions for these oscillations to occur due to the steep temperature gradient along the tubing. These oscillations create errors in measurements as well as an undesirable heat load to the system. The work presented here develops engineering guidelines to design oscillation-free helium piping. This workmorealso studies the effect of different piping inserts and shows how the proper geometrical combinations have to be chosen to avoid thermo-acoustic oscillations. The effect of an 80 K intercept is also studied and shows that thermo-oscillations can be dampened by placing the intercept at an appropriate location. As a result, the design of helium piping based on the present work is also verified with the experimental results available in open literature.less

  16. Helium in chirped laser fields as a time-asymmetric atomic switch

    SciTech Connect

    Kaprlov-?nsk, Petra Ruth; Moiseyev, Nimrod

    2014-07-07

    Tuning the laser parameters exceptional points in the spectrum of the dressed laser helium atom are obtained. The weak linearly polarized laser couples the ground state and the doubly excited P-states of helium. We show here that for specific chirped laser pulses that encircle an exceptional point one can get the time-asymmetric phenomenon, where for a negative chirped laser pulse the ground state is transformed into the doubly excited auto-ionization state, while for a positive chirped laser pulse the resonance state is not populated and the neutral helium atoms remains in the ground state as the laser pulse is turned off. Moreover, we show that the results are very sensitive to the closed contour we choose. This time-asymmetric state exchange phenomenon can be considered as a time-asymmetric atomic switch. The optimal time-asymmetric switch is obtained when the closed loop that encircles the exceptional point is large, while for the smallest loops, the time-asymmetric phenomenon does not take place. A systematic way for studying the effect of the chosen closed contour that encircles the exceptional point on the time-asymmetric phenomenon is proposed.

  17. Investigation of Countercurrent Helium-Air Flows in Air-ingress Accidents for VHTRs

    SciTech Connect

    Sun, Xiaodong; Christensen, Richard; Oh, Chang

    2013-10-03

    The primary objective of this research is to develop an extensive experimental database for the air- ingress phenomenon for the validation of computational fluid dynamics (CFD) analyses. This research is intended to be a separate-effects experimental study. However, the project team will perform a careful scaling analysis prior to designing a scaled-down test facility in order to closely tie this research with the real application. As a reference design in this study, the team will use the 600 MWth gas turbine modular helium reactor (GT-MHR) developed by General Atomic. In the test matrix of the experiments, researchers will vary the temperature and pressure of the helium— along with break size, location, shape, and orientation—to simulate deferent scenarios and to identify potential mitigation strategies. Under support of the Department of Energy, a high-temperature helium test facility has been designed and is currently being constructed at Ohio State University, primarily for high- temperature compact heat exchanger testing for the VHTR program. Once the facility is in operation (expected April 2009), this study will utilize high-temperature helium up to 900°C and 3 MPa for loss-of-coolant accident (LOCA) depressurization and air-ingress experiments. The project team will first conduct a scaling study and then design an air-ingress test facility. The major parameter to be measured in the experiments is oxygen (or nitrogen) concentration history at various locations following a LOCA scenario. The team will use two measurement techniques: 1) oxygen (or similar type) sensors employed in the flow field, which will introduce some undesirable intrusiveness, disturbing the flow, and 2) a planar laser-induced fluorescence (PLIF) imaging technique, which has no physical intrusiveness to the flow but requires a transparent window or test section that the laser beam can penetrate. The team will construct two test facilities, one for high-temperature helium tests with

  18. Nucleosynthesis in helium-enriched asymptotic giant branch models: Implications for heavy element enrichment in ω Centauri

    SciTech Connect

    Karakas, Amanda I.; Marino, Anna F.; Nataf, David M.

    2014-03-20

    We investigate the effect of helium enrichment on the evolution and nucleosynthesis of low-mass asymptotic giant branch (AGB) stars of 1.7 M {sub ☉} and 2.36 M {sub ☉} with a metallicity of Z = 0.0006 ([Fe/H] ≈–1.4). We calculate evolutionary sequences with the primordial helium abundance (Y = 0.24) and with helium-enriched compositions (Y = 0.30, 0.35, 0.40). For comparison, we calculate models of the same mass but at a lower metallicity Z = 0.0003 ([Fe/H] ≈–1.8) with Y = 0.24. Post-processing nucleosynthesis calculations are performed on each of the evolutionary sequences to determine the production of elements from hydrogen to bismuth. Elemental surface abundance predictions and stellar yields are presented for each model. The models with enriched helium have shorter main sequence and AGB lifetimes, and they enter the AGB with a more massive hydrogen-exhausted core than the primordial helium model. The main consequences are as follows: (1) low-mass AGB models with enhanced helium will evolve more than twice as fast, giving them the chance to contribute sooner to the chemical evolution of the forming globular clusters, and (2) the stellar yields will be strongly reduced relative to their primordial helium counterparts. An increase of ΔY = 0.10 at a given mass decreases the yields of carbon by up to ≈60% and of fluorine by up to 80%; it also decreases the yields of the s-process elements barium and lanthanum by ≈45%. While the yields of first s-process peak elements strontium, yttrium, and zirconium decrease by up to 50%, the yields of rubidium either do not change or increase.

  19. Vegetation Response to Carbon Dioxide and Climate: Data from the Carbon Dioxide Information Analysis Center (CDIAC)

    DOE Data Explorer

    CDIAC products are indexed and searchable through a customized interface powered by ORNL's Mercury search engine. Products include numeric data packages, publications, trend data, atlases, and models and can be searched for by subject area, keywords, authors, product numbers, time periods, collection sites, spatial references, etc. Some of the collections may also be included in the CDIAC publication Trends Online: A Compendium of Global Change Data. Most data sets, many with numerous data files, are free to download from CDIAC's ftp area. Information related to vegetation response to carbon dioxide and climate includes: • Area and Carbon Content of Sphagnum Since Last Glacial Maximum (2002) (Trends Online) • TDE Model Intercomparison Project Data Archive • Presentations and abstracts from the recent DOE Terrestrial Science Team Meeting (Argonne National Laboratory, October 29-31, 2001) • FACE (Free-Air CO2 Enrichment) • Walker Branch Throughfall Displacement Experiment Data Report: Site Characterization, System Performance, Weather, Species Composition, and Growth (2001) • Bibliography on CO2 Effects on Vegetation and Ecosystems: 1990-1999 Literature (2000) • Direct effects of atmospheric CO2 enrichment on plants and ecosystems: An updated bibliographic data base (1994) • A Database of Herbaceous Vegetation Responses to Elevated Atmospheric CO2 (1999) • A Database of Woody Vegetation Responses to Elevated Atmospheric CO2 (1999) • Forest Responses to Anthropogenic Stress (FORAST) Database (1995) • Effects of CO2 and Nitrogen Fertilization on Growth and Nutrient Content of Juvenile Ponderosa Pine (1998) • Carbon Dioxide Enrichment: Data on the Response of Cotton to Varying CO2Irrigation, and Nitrogen (1992) • Growth and Chemical Responses to CO2 Enrichment Virginia Pine Pinus Virginiana Mill.(1985)

  20. Dependence of electrophysical properties on structure of vanadium dioxide films

    SciTech Connect

    Aleksandrov, Yu.A.; Baryshnikov, Yu.Yu.; Zakharov, I.L.; Makin, G.I.; Terman, M.Yu.

    1988-02-01

    Among the inorganic materials with a metal-semiconductor phase transition (MSPT), vanadium dioxide attracts much theoretical and practical interest for two reasons. First, the maximum change in the electrical conductivity at the MSPT point is of order of magnitudes, and secondly, since the temperature T/sub P/ at the MSPT point is about 68/sup 0/C, neither high nor low temperature techniques are required for the utilization of VO/sub 2/. We study the mixture and structural-morphological condition of thin films (0.01-2 ..mu..m) of vanadium dioxide as well as the relation between the films and the change in the resistivity in the MSPT temperature range. The resistivity of the vanadium dioxide films was measured by a standard four probe method.

  1. Supercritical fluid carbon dioxide cleaning of plutonium parts

    SciTech Connect

    Hale, S.J.

    1991-12-31

    Supercritical fluid carbon dioxide is under investigation in this work for use as a cleaning solvent for the final cleaning of plutonium parts. These parts must be free of organic residue to avoid corrosion in the stockpile. Initial studies on stainless steel and full-scale mock-up parts indicate that the oils of interest are easily and adequately cleaned from the metal surfaces with supercritical fluid carbon dioxide. Results from compatibility studies show that undesirable oxidation or other surface reactions are not occurring during exposure of plutonium to the supercritical fluid. Cleaning studies indicate that the oils of interest are removed from the plutonium surface under relatively mild conditions. These studies indicate that supercritical fluid carbon dioxide is a very promising cleaning medium for this application.

  2. CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS

    SciTech Connect

    David A. Green; Brian S. Turk; Jeffrey W. Portzer; Raghubir P. Gupta; William J. McMichael; Thomas Nelson

    2004-07-01

    This report describes research conducted between April 1, 2004 and June 30, 2004 on the preparation and use of dry regenerable sorbents for removal of carbon dioxide from flue gas. Support materials and supported sorbents were prepared by spray drying. Sorbents consisting of 20 to 50% sodium carbonate on a ceramic support were prepared by spray drying in batches of approximately 300 grams. The supported sorbents exhibited greater carbon dioxide capture rates than unsupported calcined sodium bicarbonate in laboratory tests. Preliminary process design and cost estimation for a retrofit application suggested that costs of a dry regenerable sodium carbonate-based process could be lower than those of a monoethanolamine absorption system. In both cases, the greatest part of the process costs come from power plant output reductions due to parasitic consumption of steam for recovery of carbon dioxide from the capture medium.

  3. Carbon Dioxide Capture from Flue Gas Using Dry, Regenerable Sorbents

    SciTech Connect

    David A. Green; Thomas O. Nelson; Brian S. Turk; Paul D. Box Raghubir P. Gupta

    2006-09-30

    This report describes research conducted between July 1, 2006 and September 30, 2006 on the use of dry regenerable sorbents for removal of carbon dioxide (CO{sub 2}) from coal combustion flue gas. Modifications to the integrated absorber/ sorbent regenerator/ sorbent cooler system were made to improve sorbent flow consistency and measurement reliability. Operation of the screw conveyor regenerator to achieve a sorbent temperature of at least 120 C at the regenerator outlet is necessary for satisfactory carbon dioxide capture efficiencies in succeeding absorption cycles. Carbon dioxide capture economics in new power plants can be improved by incorporating increased capacity boilers, efficient flue gas desulfurization systems and provisions for withdrawal of sorbent regeneration steam in the design.

  4. Beneficial Use of Carbon Dioxide in Precast Concrete Production

    SciTech Connect

    Shao, Yixin

    2014-06-26

    The feasibility of using carbon dioxide as feedstock in precast concrete production is studied. Carbon dioxide reacts with calcium compounds in concrete, producing solid calcium carbonates in binding matrix. Two typical precast products are examined for their capacity to store carbon dioxide during the production. They are concrete blocks and fiber-cement panels. The two products are currently mass produced and cured by steam. Carbon dioxide can be used to replace steam in curing process to accelerate early strength, improve the long-term durability and reduce energy and emission. For a reaction within a 24-hour process window, the theoretical maximum possible carbon uptake in concrete is found to be 29% based on cement mass in the product. To reach the maximum uptake, a special process is developed to promote the reaction efficiency to 60-80% in 4-hour carbon dioxide curing and improve the resistance to freeze-thaw cycling and sulfate ion attack. The process is also optimized to meet the project target of $10/tCO2 in carbon utilization. By the use of self-concentrating absorption technology, high purity CO2 can be produced at a price below $40/t. With low cost CO2 capture and utilization technologies, it is feasible to establish a network for carbon capture and utilization at the vicinity of carbon sources. If all block produces and panel producers in United States could adopt carbon dioxide process in their production in place of steam, carbon utilization in these two markets alone could consume more than 2 Mt CO2/year. This capture and utilization process can be extended to more precast products and will continue for years to come.

  5. Water and Carbon Dioxide Adsorption at Olivine Surfaces

    SciTech Connect

    Kerisit, Sebastien N.; Bylaska, Eric J.; Felmy, Andrew R.

    2013-11-14

    Plane-wave density functional theory (DFT) calculations were performed to simulate water and carbon dioxide adsorption at the (010) surface of five olivine minerals, namely, forsterite (Mg2SiO4), calcio-olivine (Ca2SiO4), tephroite (Mn2SiO4), fayalite (Fe2SiO4), and Co-olivine (Co2SiO4). Adsorption energies per water molecule obtained from energy minimizations varied from -78 kJ mol-1 for fayalite to -128 kJ mol-1 for calcio-olivine at sub-monolayer coverage and became less exothermic as coverage increased. In contrast, carbon dioxide adsorption energies at sub-monolayer coverage ranged from -20 kJ mol-1 for fayalite to -59 kJ mol-1 for calcio-olivine. Therefore, the DFT calculations show a strong driving force for carbon dioxide displacement by water at the surface of all olivine minerals in a competitive adsorption scenario. Additionally, adsorption energies for both water and carbon dioxide were found to be more exothermic for the alkaline-earth (AE) olivines than for the transition-metal (TM) olivines and to not correlate with the solvation enthalpies of the corresponding divalent cations. However, a correlation was obtained with the charge of the surface divalent cation indicating that the more ionic character of the AE cations in the olivine structure relative to the TM cations leads to greater interactions with adsorbed water and carbon dioxide molecules at the surface and thus more exothermic adsorption energies for the AE olivines. For calcio-olivine, which exhibits the highest divalent cation charge of the five olivines, ab initio molecular dynamics simulations showed that this effect leads both water and carbon dioxide to react with the surface and form hydroxyl groups and a carbonate-like species, respectively.

  6. Dose dependence of helium bubble formation in nano-engineered SiC at 700 °C

    DOE PAGES [OSTI]

    Chen, Chien -Hung; Zhang, Yanwen; Wang, Yongqiang; Crespillo, Miguel L.; Fontana, Cristiano L.; Graham, Joseph T.; Duscher, Gerd; Shannon, Steven C.; Weber, William J.

    2016-02-03

    Knowledge of radiation-induced helium bubble nucleation and growth in SiC is essential for applications in fusion and fission environments. Here we report the evolution of microstructure in nano-engineered (NE) 3C SiC, pre-implanted with helium, under heavy ion irradiation at 700 °C up to doses of 30 displacements per atom (dpa). Elastic recoil detection analysis confirms that the as-implanted helium depth profile does not change under irradiation to 30 dpa at 700 °C. While the helium bubble size distribution becomes narrower with increasing dose, the average size of bubbles remains unchanged and the density of bubbles increases somewhat with dose. Thesemore » results are consistent with a long helium bubble incubation process under continued irradiation at 700 °C up to 30 dpa, similar to that reported under dual and triple beam irradiation at much higher temperatures. The formation of bubbles at this low temperature is enhanced by the nano-layered stacking fault structure in the NE SiC, which enhances point defect mobility parallel to the stacking faults. Here, this stacking fault structure is stable at 700 °C up to 30 dpa and suppresses the formation of dislocation loops normally observed under these irradiation conditions.« less

  7. Use of Multiple Reheat Helium Brayton Cycles to Eliminate the Intermediate Heat Transfer Loop for Advanced Loop Type SFRs

    SciTech Connect

    Haihua Zhao; Hongbin Zhang; Samuel E. Bays

    2009-05-01

    The sodium intermediate heat transfer loop is used in existing sodium cooled fast reactor (SFR) plant design as a necessary safety measure to separate the radioactive primary loop sodium from the water of the steam Rankine power cycle. However, the intermediate heat transfer loop significantly increases the SFR plant cost and decreases the plant reliability due to the relatively high possibility of sodium leakage. A previous study shows that helium Brayton cycles with multiple reheat and intercooling for SFRs with reactor outlet temperature in the range of 510°C to 650°C can achieve thermal efficiencies comparable to or higher than steam cycles or recently proposed supercritical CO2 cycles. Use of inert helium as the power conversion working fluid provides major advantages over steam or CO2 by removing the requirement for safety systems to prevent and mitigate the sodium-water or sodium-CO2 reactions. A helium Brayton cycle power conversion system therefore makes the elimination of the intermediate heat transfer loop possible. This paper presents a pre-conceptual design of multiple reheat helium Brayton cycle for an advanced loop type SFR. This design widely refers the new horizontal shaft distributed PBMR helium power conversion design features. For a loop type SFR with reactor outlet temperature 550°C, the design achieves 42.4% thermal efficiency with favorable power density comparing with high temperature gas cooled reactors.

  8. High-Efficiency Receivers for Supercritical Carbon Dioxide Cycles |

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Department of Energy High-Efficiency Receivers for Supercritical Carbon Dioxide Cycles High-Efficiency Receivers for Supercritical Carbon Dioxide Cycles This fact sheet describes a project awarded under the DOE's 2012 SunShot Concentrating Solar Power R&D award program. The team, led by Brayton Energy, aims to develop and demonstrate a low-cost, high-efficiency solar receiver that is compatible with s-CO2 cycles and modern thermal storage subsystems. Supercritical CO2 Brayton-cycle

  9. Helium transport and ash control studies. Annual progress report, 1 June 1991--31 March 1992

    SciTech Connect

    Miley, G.H.

    1992-06-01

    The Primary goal of this research is to develop a helium (ash) transport scaling law based on experimental data from devices such as TFTR and JET. To illustrate the importance of this, we have studied ash accumulation effects on ignition requirements using a O-D transport model. Ash accumulation is characterized in the model by the ratio of the helium particle confinement time to the energy confinement time t{sub {alpha}}/t{sub E}. Results show that the ignition ``window`` shrinks rapidly as t{sub {alpha}}/t{sub E} increases, closing for high t{sub {alpha}}/t{sub E} increases, closing for high t{sub {alpha}}/t{sub E}. A ``best`` value for t{sub {alpha}}/t{sub E} will ultimately be determined from our scaling law studies. A helium transport scaling law is being sought that expresses the transport coefficients (D{sub {alpha}}, V{sub {alpha}}) as a function of the local plasma parameters. This is necessary for use in transport code calculations, e.g. for BALDUR. Based on experimental data from L-mode plasma operation in TFTR, a scaling law to a power law expression has been obtained using a least-square fit method. It is found that the transport coefficients are strongly affected by the local magnetic field and safety factor q. A preliminary conclusion from this work is that active control of ash buildup must be developed. To study control, we have developed a O-D plasma model which employs a simple pole-placement control model. Some preliminary calculations with this model are presented.

  10. A passively-safe fusion reactor blanket with helium coolant and steel structure

    SciTech Connect

    Crosswait, K.M.

    1994-04-01

    Helium is attractive for use as a fusion blanket coolant for a number of reasons. It is neutronically and chemically inert, nonmagnetic, and will not change phase during any off-normal or accident condition. A significant disadvantage of helium, however, is its low density and volumetric heat capacity. This disadvantage manifests itself most clearly during undercooling accident conditions such as a loss of coolant accident (LOCA) or a loss of flow accident (LOFA). This thesis describes a new helium-cooled tritium breeding blanket concept which performs significantly better during such accidents than current designs. The proposed blanket uses reduced-activation ferritic steel as a structural material and is designed for neutron wall loads exceeding 4 MW/m{sup 2}. The proposed geometry is based on the nested-shell concept developed by Wong, but some novel features are used to reduce the severity of the first wall temperature excursion. These features include the following: (1) A ``beryllium-joint`` concept is introduced, which allows solid beryllium slabs to be used as a thermal conduction path from the first wall to the cooler portions of the blanket. The joint concept allows for significant swelling of the beryllium (10 percent or more) without developing large stresses in the blanket structure. (2) Natural circulation of the coolant in the water-cooled shield is used to maintain shield temperatures below 100 degrees C, thus maintaining a heat sink close to the blanket during the accident. This ensures the long-term passive safety of the blanket.

  11. Probing Electron Correlation via Attosecond xuv Pulses in the Two-Photon Double Ionization of Helium

    SciTech Connect

    Feist, J.; Nagele, S.; Pazourek, R.; Persson, E.; Burgdoerfer, J.; Schneider, B. I.; Collins, L. A.

    2009-08-07

    Recent experimental developments of high-intensity, short-pulse extreme ultraviolet light sources are enhancing our ability to study electron-electron correlations. We perform time-dependent calculations to investigate the so-called 'sequential' regime ((Planck constant/2pi)omega>54.4 eV) in the two-photon double ionization of helium. We show that attosecond pulses allow us not only to probe but also to induce angular and energy correlations of the emitted electrons. The final momentum distribution reveals regions dominated by the Wannier ridge breakup scenario and by postcollision interaction.

  12. Fabrication of carbon nanotube nanogap electrodes by helium ion sputtering for molecular contacts

    SciTech Connect

    Thiele, Cornelius; Vieker, Henning; Beyer, André; Gölzhäuser, Armin; Flavel, Benjamin S.; Hennrich, Frank; Muñoz Torres, David; Eaton, Thomas R.; Mayor, Marcel; Kappes, Manfred M.; Löhneysen, Hilbert v.; and others

    2014-03-10

    Carbon nanotube nanogaps have been used to contact individual organic molecules. However, the reliable fabrication of a truly nanometer-sized gap remains a challenge. We use helium ion beam lithography to sputter nanogaps of only (2.8 ± 0.6) nm size into single metallic carbon nanotubes embedded in a device geometry. The high reproducibility of the gap size formation provides a reliable nanogap electrode testbed for contacting small organic molecules. To demonstrate the functionality of these nanogap electrodes, we integrate oligo(phenylene ethynylene) molecular rods, and measure resistance before and after gap formation and with and without contacted molecules.

  13. Operating experience with gas-bearing circulators in a high-pressure helium loop

    SciTech Connect

    Sanders, J.P.; Gat, Uri; Young, H.C.

    1987-01-01

    A high-pressure engineering test loop has been designed and constructed at the Oak Ridge National Laboratory for circulating helium through a test chamber at temperatures to 1000/sup 0/C. The purpose of this loop is to determine the thermal and structural performance of proposed components for the primary loops of gas-cooled nuclear reactors. Five MW of power is available to provide the required gas temperature at the test chamber, and an air-cooled heat exchanger, rated at 4.4 MW, serves as a heat sink. This report contains results of tests performed on gas-bearing circulators.

  14. Deep Burn Develpment of Transuranic Fuel for High-Temperature Helium-Cooled Reactors - July 2010

    SciTech Connect

    Snead, Lance Lewis; Besmann, Theodore M; Collins, Emory D; Bell, Gary L

    2010-08-01

    The DB Program Quarterly Progress Report for April - June 2010, ORNL/TM/2010/140, was distributed to program participants on August 4. This report discusses the following: (1) TRU (transuranic elements) HTR (high temperature helium-cooled reactor) Fuel Modeling - (a) Thermochemical Modeling, (b) 5.3 Radiation Damage and Properties; (2) TRU HTR Fuel Qualification - (a) TRU Kernel Development, (b) Coating Development, (c) ZrC Properties and Handbook; and (3) HTR Fuel Recycle - (a) Recycle Processes, (b) Graphite Recycle, (c) Pyrochemical Reprocessing - METROX (metal recovery from oxide fuel) Process Development.

  15. Numerical simulation of alumina spraying in argon-helium plasma jet

    SciTech Connect

    Chang, C.H.

    1992-01-01

    A new numerical model is described for simulating thermal plasmas containing entrained particles, with emphasis on plasma spraying applications. The plasma is represented as a continuum multicomponent chemically reacting ideal gas, while the particles are tracked as discrete Lagrangian entities coupled to the plasma. Computational results are presented from a transient simulation of alumina spraying in a turbulent argon-helium plasma jet in air environment, including torch geometry, substrate, and multiple species with chemical reactions. Particle-plasma interactions including turbulent dispersion have been modeled in a fully self-consistent manner. Interactions between the plasma and the torch and substrate walls are modeled using wall functions. (15 refs.)

  16. Numerical simulation of alumina spraying in argon-helium plasma jet

    SciTech Connect

    Chang, C.H.

    1992-08-01

    A new numerical model is described for simulating thermal plasmas containing entrained particles, with emphasis on plasma spraying applications. The plasma is represented as a continuum multicomponent chemically reacting ideal gas, while the particles are tracked as discrete Lagrangian entities coupled to the plasma. Computational results are presented from a transient simulation of alumina spraying in a turbulent argon-helium plasma jet in air environment, including torch geometry, substrate, and multiple species with chemical reactions. Particle-plasma interactions including turbulent dispersion have been modeled in a fully self-consistent manner. Interactions between the plasma and the torch and substrate walls are modeled using wall functions. (15 refs.)

  17. Energy-Related Carbon Dioxide Emissions at the State Level, 2000...

    Energy Information Administration (EIA) (indexed site)

    6 Table 1. State energy-related carbon dioxide emissions by year (2000-2013) million metric tons carbon dioxide Change (2000-2013) State 2000 2001 2002 2003 2004 2005 2006 2007 ...

  18. Energy-Related Carbon Dioxide Emissions at the State Level, 2000...

    Energy Information Administration (EIA) (indexed site)

    4 Table 5. Per capita energy-related carbon dioxide emissions by state (2000-2013) metric tons carbon dioxide per person Change (2000-2013) State 2000 2001 2002 2003 2004 2005 2006 ...

  19. Energy-Related Carbon Dioxide Emissions at the State Level, 2000...

    Energy Information Administration (EIA) (indexed site)

    8 Table 2. 2013 state energy-related carbon dioxide emissions by fuel million metric tons of carbon dioxide Shares State Coal Petroleum Natural Gas Total Coal Petroleum Natural Gas ...

  20. In Milestone, Energy Department Projects Safely and Permanently Store 10 Million Metric Tons of Carbon Dioxide

    Energy.gov [DOE]

    Carbon Capture and Storage projects supported by the Department reached a milestone of 10 million tons of carbon dioxide.

  1. Low-Cost, High-Accuracy, Whole-Building Carbon Dioxide Monitoring for Demand Control Ventilation

    Energy.gov [DOE]

    Lead Performer: Dioxide Materials™ – Boca Raton, FL Partner: I-SENSE at Florida Atlantic University – Boca Raton, FL

  2. Silicon dioxide and hafnium dioxide evaporation characteristics from a high-frequency sweep e-beam system

    SciTech Connect

    Chow, R. [Lawrence Livermore National Laboratory, Livermore, California 94551-0808 (United States); Tsujimoto, N. [MDC Vacuum Products Corporation, Hayward, California 94545 (United States)

    1996-09-01

    Reactive oxygen evaporation characteristics were determined as a function of the front-panel control parameters provided by a programmable, high-frequency sweep e-beam system. An experimental design strategy used deposition rate, beam speed, pattern, azimuthal rotation speed, and dwell time as the variables. The optimal settings for obtaining a broad thickness distribution, efficient silicon dioxide boule consumption, and minimal hafnium dioxide defect density were generated. The experimental design analysis showed the compromises involved with evaporating these oxides. {copyright} {ital 1996 Optical Society of America.}

  3. Cavity morphology in a Ni based superalloy under heavy ion irradiation with cold pre-injected helium. I

    SciTech Connect

    Zhang, He; Yao, Zhongwen Daymond, Mark R.; Kirk, Marquis A.

    2014-03-14

    In order to understand radiation damage in the nickel based superalloy Inconel X-750 in thermal reactors, where (n, ?) transmutation reaction also occurred in addition to fast neutron induced atomic displacement, heavy ion (1?MeV Kr{sup 2+}) irradiation with pre-injected helium was performed under in-situ observations of an intermediate voltage electron microscope at Argonne National Laboratory. By comparing to our previous studies using 1?MeV Kr{sup 2+} irradiation solely, the pre-injected helium was found to be essential in cavity nucleation. Cavities started to be visible after Kr{sup 2+} irradiation to 2.7 dpa at ?200?C in samples containing 200 appm, 1000 appm, and 5000 appm helium, respectively, but not at lower temperatures. The cavity growth was observed during the continuous irradiation. Cavity formation appeared along with a reduced number density of stacking fault tetrahedra, vacancy type defects. With higher pre-injected helium amount, a higher density of smaller cavities was observed. This is considered to be the result of local trapping effect of helium which disperses vacancies. The average cavity size increases with increasing irradiation temperatures; the density reduced; and the distribution of cavities became heterogeneous at elevated temperatures. In contrast to previous characterization of in-reactor neutron irradiated Inconel X-750, no obvious cavity sink to grain boundaries and phase boundaries was found even at high doses and elevated temperatures. MC-type carbides were observed as strong sources for agglomeration of cavities due to their enhanced trapping strength of helium and vacancies.

  4. Stepped-anneal and total helium/hydrogen measurements in high-energy proton-irradiated tungsten

    SciTech Connect

    Oliver, B.M.; Hamilton, M.L.; Garner, F.A.; Sommer, W.F.; Maloy, S.A.; Ferguson, P.D.

    1998-12-31

    To provide structural material design data for the Accelerator Production of Tritium (APT) project, a 1 mA, 800 MeV proton beam at the Los Alamos Neutron Science Center (LANSCE) was used to irradiate a large number of metal samples, including a tungsten target similar to that being considered as the neutron source for the tritium production. The maximum proton fluence to the tungsten target was {approximately} 10{sup 21} protons/cm{sup 2}. An unavoidable byproduct of spallation reactions is the formation of large amounts of hydrogen and helium. Postulated accident scenarios for APT involving the use of tungsten rods clad with Alloy 718, raise concerns as to the amount and rate of release of these gases due to temperatures increases from afterheat accumulation, with the major concern being pressurizing and possibly failure of the cladding. To address these issues, portions of the LANSCE tungsten rods were subjected to temperature histories calculated as likely to occur, and the time-dependent evolution of helium and hydrogen gases was measured. Stepped-anneal and total helium/hydrogen measurements were conducted on multiple samples of the tungsten material. Helium measurements were conducted at Pacific Northwest National Laboratory (PNNL) using a high-sensitivity magnetic-sector isotope-dilution helium analysis system. Stepped-anneal measurements were conducted at temperatures from {approximately} 25 C to {approximately} 1,600 C in {approximately} 100 C steps. Total helium measurements were conducted by rapid vaporization after completion of the stepped-anneal process, and are compared with Monte Carlo calculations performed at Los Alamos National Laboratory (LANL) using the LAHET code system. Hydrogen measurements were conducted between {approximately} 750 C and {approximately} 1,200 C using a high-temperature furnace that had been extensively modified for the application. Hydrogen detection was accomplished by periodic sampling of the furnace gas using a separate

  5. Cobalt carbonyl catalyzed olefin hydroformylation in supercritical carbon dioxide

    DOEpatents

    Rathke, Jerome W. (Lockport, IL); Klingler, Robert J. (Westmount, IL)

    1993-01-01

    A method of olefin hydroformylation is provided wherein an olefin reacts with a carbonyl catalyst and with reaction gases such as hydrogen and carbon monoxide in the presence of a supercritical reaction solvent, such as carbon dioxide. The invention provides higher yields of n-isomer product without the gas-liquid mixing rate limitation seen in conventional Oxo processes using liquid media.

  6. Cobalt carbonyl catalyzed olefin hydroformylation in supercritical carbon dioxide

    DOEpatents

    Rathke, J.W.; Klingler, R.J.

    1993-03-30

    A method of olefin hydroformylation is provided wherein an olefin reacts with a carbonyl catalyst and with reaction gases such as hydrogen and carbon monoxide in the presence of a supercritical reaction solvent, such as carbon dioxide. The invention provides higher yields of n-isomer product without the gas-liquid mixing rate limitation seen in conventional Oxo processes using liquid media.

  7. Flow instabilities in non-uniformly heated helium jet arrays used for divertor PFCs

    SciTech Connect

    Youchison, Dennis L.

    2015-07-30

    In this study, due to a lack of prototypical experimental data, little is known about the off-normal behavior of recently proposed divertor jet cooling concepts. This article describes a computational fluid dynamics (CFD) study on two jet array designs to investigate their susceptibility to parallel flow instabilities induced by non-uniform heating and large increases in the helium outlet temperature. The study compared a single 25-jet helium-cooled modular divertor (HEMJ) thimble and a micro-jet array with 116 jets. Both have pure tungsten armor and a total mass flow rate of 10 g/s at a 600 C inlet temperature. We investigated flow perturbations caused by a 30 MW/m2 off-normal heat flux applied over a 25 mm2 area in addition to the nominal 5 MW/m2 applied over a 75 mm2 portion of the face. The micro-jet array exhibited lower temperatures and a more uniform surface temperature distribution than the HEMJ thimble. We also investigated the response of a manifolded nine-finger HEMJ assembly using the nominal heat flux and a 274 mm2 heated area.

  8. Influence of helium puff on divertor asymmetry in Experimental Advanced Superconducting Tokamak

    SciTech Connect

    Liu, S. C., E-mail: lshch@ipp.ac.cn; Xu, G. S.; Wang, H. Q.; Ding, R.; Duan, Y. M.; Gan, K. F.; Shao, L. M.; Chen, L.; Zhang, W.; Chen, R.; Xiong, H.; Ding, S.; Hu, G. H.; Liu, Y. L.; Zhao, N.; Li, Y. L.; Gao, X. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)] [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Guo, H. Y. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China) [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Tri Alpha Energy, Inc., Post Office Box 7010, Rancho Santa Margarita, California 92688 (United States); Wang, L. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China) [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); School of Physics and Optoelectronic Technology, Dalian university of Technology, Dalian 116024 (China); Yan, N. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China) [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Association Euratom-Ris DTU, DK-4000 Roskilde (Denmark)

    2014-02-15

    Divertor asymmetries with helium puffing are investigated in various divertor configurations on Experimental Advanced Superconducting Tokamak (EAST). The outer divertor electron temperature decreases significantly during the gas injection at the outer midplane. As soon as the gas is injected into the edge plasma, the power deposition drops sharply at the lower outer target while increases gradually at the lower inner target in LSN configuration; the power deposition increases quickly at the upper outer target while remains unchanged at the upper inner target in upper single null configuration; the power deposition increases slightly at the outer targets while shows no obvious variation at the inner targets in double null configuration. The radiated power measured by the extreme ultraviolet arrays increases significantly due to helium gas injection, especially in the outer divertor. The edge parameters are measured by reciprocating probes at the outer midplane, showing that the electron temperature and density increase but the parallel Mach number decreases significantly due to the gas injection. Effects of poloidal E??B drifts and parallel SOL flows on the divertor asymmetry observed in EAST are also discussed.

  9. Helium bubble linkage and the transition to rapid He release in aging Pd tritide.

    SciTech Connect

    Cowgill, Donald F.

    2006-02-01

    A model is presented for the linking of helium bubbles growing in aging metal tritides. Stresses created by neighboring bubbles are found to produce bubble growth toward coalescence. This process is interrupted by the fracture of ligaments between bubble arrays. The condition for ligament fracture percolates through the material to reach external surfaces, leading to material micro-cracking and the release of helium within the linked-bubble cluster. A comparison of pure coalescence and pure fracture mechanisms shows the critical HeM concentration for bubble linkage is not strongly dependent on details of the linkage process. The combined stress-directed growth and fracture process produces predictions for the onset of rapid He release and the He emission rate. Transition to this rapid release state is determined from the physical size of the linked-bubble clusters, which is calculated from dimensional invariants in classical percolation theory. The result is a transition that depends on material dimensions. The onset of bubble linkage and rapid He release are found to be quite sensitive to the bubble spacing distribution, which is log-normal for bubbles nucleated by self-trapping.

  10. Constraints on helium enhancement in the globular cluster M4 (NGC 6121): The horizontal branch test

    SciTech Connect

    Valcarce, A. A. R.; De Medeiros, J. R.; Catelan, M.; Alonso-Garca, J.; Corts, C.

    2014-02-20

    Recent pieces of evidence have revealed that most, and possibly all, globular star clusters are composed of groups of stars that formed in multiple episodes with different chemical compositions. In this sense, it has also been argued that variations in the initial helium abundance (Y) from one population to the next are also the rule, rather than the exception. In the case of the metal-intermediate globular cluster M4 (NGC 6121), recent high-resolution spectroscopic observations of blue horizontal branch (HB) stars (i.e., HB stars hotter than the RR Lyrae instability strip) suggest that a large fraction of blue HB stars are second-generation stars formed with high helium abundances. In this paper, we test this scenario by using recent photometric and spectroscopic data together with theoretical evolutionary computations for different Y values. Comparing the photometric data with the theoretically derived color-magnitude diagrams, we find that the bulk of the blue HB stars in M4 have ?Y ? 0.01 with respect to the cluster's red HB stars (i.e., HB stars cooler than the RR Lyrae strip)a result which is corroborated by comparison with spectroscopically derived gravities and temperatures, which also favor little He enhancement. However, the possible existence of a minority population on the blue HB of the cluster with a significant He enhancement level is also discussed.

  11. Unusual behavior in magnesium-copper cluster matter produced by helium droplet mediated deposition

    SciTech Connect

    Emery, S. B. Little, B. K.; Xin, Y.; Ridge, C. J.; Lindsay, C. M.; Buszek, R. J.; Boatz, J. A.; Boyle, J. M.

    2015-02-28

    We demonstrate the ability to produce core-shell nanoclusters of materials that typically undergo intermetallic reactions using helium droplet mediated deposition. Composite structures of magnesium and copper were produced by sequential condensation of metal vapors inside the 0.4 K helium droplet baths and then gently deposited onto a substrate for analysis. Upon deposition, the individual clusters, with diameters ∼5 nm, form a cluster material which was subsequently characterized using scanning and transmission electron microscopies. Results of this analysis reveal the following about the deposited cluster material: it is in the un-alloyed chemical state, it maintains a stable core-shell 5 nm structure at sub-monolayer quantities, and it aggregates into unreacted structures of ∼75 nm during further deposition. Surprisingly, high angle annular dark field scanning transmission electron microscopy images revealed that the copper appears to displace the magnesium at the core of the composite cluster despite magnesium being the initially condensed species within the droplet. This phenomenon was studied further using preliminary density functional theory which revealed that copper atoms, when added sequentially to magnesium clusters, penetrate into the magnesium cores.

  12. Commissioning of helium refrigeration system at JLab for 12 GeV upgrade

    SciTech Connect

    Ganni, Venkatarao; Dixon, Kelly D.; Knudsen, Peter N.; Norton, Robert O.; Creel, Jonathan D.

    2014-01-01

    The new 4.5 K refrigerator system added to the Jefferson Lab (JLab) Central Helium Liquefier (CHL) for the 12 GeV upgrade will double its previous capacity. It includes a 4.5 K cold box system and compressor system with associated oil removal and gas management systems. At its maximum capacity condition, this new system supports an additional 238 g/s 30 K 1.16 bar cold compressor return flow, a 15 g/s 4.5 K liquefaction load and a 12.6 kW 35–55 K shield load. Five more design conditions, ranging from liquefaction to refrigeration and a stand-by/reduced load state, were specified for the sizing and selection of its components. The cold box system is comprised of a 300–60 K vertical cold box that incorporates a liquid nitrogen pre-cooler and a 60–4.5 K horizontal cold box housing seven turbines that are configured in four expansion stages including one Joule-Thompson expander. The helium compression system has five compressors to support three pressure levels in the cold box. This paper will briefly review the salient 4.5 K system design features and discuss the recent commissioning results.

  13. OPTIMAL DESIGN AND OPERATION OF HELIUM REFRIGERATION SYSTEMS USING THE GANNI CYCLE

    SciTech Connect

    Venkatarao Ganni, Peter Knudsen

    2010-04-01

    The constant pressure ratio process, as implemented in the floating pressure - Ganni cycle, is a new variation to prior cryogenic refrigeration and liquefaction cycle designs that allows for optimal operation and design of helium refrigeration systems. This cycle is based upon the traditional equipment used for helium refrigeration system designs, i.e., constant volume displacement compression and critical flow expansion devices. It takes advantage of the fact that for a given load, the expander sets the compressor discharge pressure and the compressor sets its own suction pressure. This cycle not only provides an essentially constant system Carnot efficiency over a wide load range, but invalidates the traditional philosophy that the (‘TS’) design condition is the optimal operating condition for a given load using the as-built hardware. As such, the Floating Pressure- Ganni Cycle is a solution to reduce the energy consumption while increasing the reliability, flexibility and stability of these systems over a wide operating range and different operating modes and is applicable to most of the existing plants. This paper explains the basic theory behind this cycle operation and contrasts it to the traditional operational philosophies presently used.

  14. Determination of effective axion masses in the helium-3 buffer of CAST

    SciTech Connect

    Ruz, J

    2011-11-18

    The CERN Axion Solar Telescope (CAST) is a ground based experiment located in Geneva (Switzerland) searching for axions coming from the Sun. Axions, hypothetical particles that not only could solve the strong CP problem but also be one of the favored candidates for dark matter, can be produced in the core of the Sun via the Primakoff effect. They can be reconverted into X-ray photons on Earth in the presence of strong electromagnetic fields. In order to look for axions, CAST points a decommissioned LHC prototype dipole magnet with different X-ray detectors installed in both ends of the magnet towards the Sun. The analysis of the data acquired during the first phase of the experiment yielded the most restrictive experimental upper limit on the axion-to-photon coupling constant for axion masses up to about 0.02 eV/c{sup 2}. During the second phase, CAST extends its mass sensitivity by tuning the electron density present in the magnetic field region. Injecting precise amounts of helium gas has enabled CAST to look for axion masses up to 1.2 eV/c{sup 2}. This paper studies the determination of the effective axion masses scanned at CAST during its second phase. The use of a helium gas buffer at temperatures of 1.8 K has required a detailed knowledge of the gas density distribution. Complete sets of computational fluid dynamic simulations validated with experimental data have been crucial to obtain accurate results.

  15. Advanced helium purge seals for Liquid Oxygen (LOX) turbopumps. Final report, September 1985-August 1987

    SciTech Connect

    Shapiro, W.; Lee, C.C.

    1989-03-01

    Program objectives were to determine three advanced configurations of helium buffer seals capable of providing improved performance in a space shuttle main engine (SSME), high-pressure liquid oxygen (LOX) turbopump environment, and to provide NASA with the analytical tools to determine performance of a variety of seal configurations. The three seal designs included solid-ring fluid-film seals often referred to as floating ring seals, back-to-back fluid-film face seals, and a circumferential sectored seal that incorporated inherent clearance adjustment capabilities. Of the three seals designed, the sectored seal is favored because the self-adjusting clearance features accommodate the variations in clearance that will occur because of thermal and centrifugal distortions without compromising performance. Moreover, leakage can be contained well below the maximum target values; minimizing leakage is important on the SSME since helium is provided by an external tank. A reduction in tank size translates to an increase in payload that can be carried on board the shuttle. The computer codes supplied under this program included a code for analyzing a variety of gas-lubricated, floating ring, and sector seals; a code for analyzing gas-lubricated face seals; a code for optimizing and analyzing gas-lubricated spiral-groove face seals; and a code for determining fluid-film face seal response to runner excitations in as many as five degrees of freedom. These codes proved invaluable for optimizing designs and estimating final performance of the seals described.

  16. Large-scale atomistic simulations of helium-3 bubble growth in complex palladium alloys

    DOE PAGES [OSTI]

    Hale, Lucas M.; Zimmerman, Jonathan A.; Wong, Bryan M.

    2016-05-18

    Palladium is an attractive material for hydrogen and hydrogen-isotope storage applications due to its properties of large storage density and high diffusion of lattice hydrogen. When considering tritium storage, the material’s structural and mechanical integrity is threatened by both the embrittlement effect of hydrogen and the creation and evolution of additional crystal defects (e.g., dislocations, stacking faults) caused by the formation and growth of helium-3 bubbles. Using recently developed inter-atomic potentials for the palladium-silver-hydrogen system, we perform large-scale atomistic simulations to examine the defect-mediated mechanisms that govern helium bubble growth. Our simulations show the evolution of a distribution of materialmore » defects, and we compare the material behavior displayed with expectations from experiment and theory. In conclusion, we also present density functional theory calculations to characterize ideal tensile and shear strengths for these materials, which enable the understanding of how and why our developed potentials either meet or confound these expectations.« less

  17. THE VALUE OF HELIUM-COOLED REACTOR TECHNOLOGIES OF NUCLEAR WASTE

    SciTech Connect

    C. RODRIGUEZ; A. BAXTER

    2001-03-01

    Helium-cooled reactor technologies offer significant advantages in accomplishing the waste transmutation process. They are ideally suited for use with thermal, epithermal, or fast neutron energy spectra. They can provide a relatively hard thermal neutron spectrum for transmutation of fissionable materials such as Pu-239 using ceramic-coated transmutation fuel particles, a graphite moderator, and a non-fertile burnable poison. These features (1) allow deep levels of transmutation with minimal or no intermediate reprocessing, (2) enhance passive decay heat removal via heat conduction and radiation, (3) allow operation at relatively high temperatures for a highly efficient generation of electricity, and (4) discharge the transmuted waste in a form that is highly resistant to corrosion for long times. They also offer the possibility for the use of epithermal neutrons that can interact with transmutable materials more effectively because of the large atomic cross sections in this energy domain. A fast spectrum may be useful for deep burnup of certain minor actinides. For this application, helium is essentially transparent to neutrons, does not degrade neutron energies, and offers the hardest possible neutron energy environment. In this paper, we report results from recent work on materials transmutation balances, safety, value to a geological repository, and economic considerations.

  18. Production of stable, non-thermal atmospheric pressure rf capacitive plasmas using gases other than helium or neon

    DOEpatents

    Park, Jaeyoung; Henins, Ivars

    2005-06-21

    The present invention enables the production of stable, steady state, non-thermal atmospheric pressure rf capacitive .alpha.-mode plasmas using gases other than helium and neon. In particular, the current invention generates and maintains stable, steady-state, non-thermal atmospheric pressure rf .alpha.-mode plasmas using pure argon or argon with reactive gas mixtures, pure oxygen or air. By replacing rare and expensive helium with more readily available gases, this invention makes it more economical to use atmospheric pressure rf .alpha.-mode plasmas for various materials processing applications.

  19. Spent Nuclear Fuel (SNF) Project Cask and MCO Helium Purge System Design Review Completion Report Project A.5 and A.6

    SciTech Connect

    ARD, K.E.

    2000-04-19

    This report documents the results of the design verification performed on the Cask and Multiple Canister Over-pack (MCO) Helium Purge System. The helium purge system is part of the Spent Nuclear Fuel (SNF) Project Cask Loadout System (CLS) at 100K area. The design verification employed the ''Independent Review Method'' in accordance with Administrative Procedure (AP) EN-6-027-01.

  20. Supercritical carbon dioxide cycle control analysis.

    SciTech Connect

    Moisseytsev, A.; Sienicki, J. J.

    2011-04-11

    This report documents work carried out during FY 2008 on further investigation of control strategies for supercritical carbon dioxide (S-CO{sub 2}) Brayton cycle energy converters. The main focus of the present work has been on investigation of the S-CO{sub 2} cycle control and behavior under conditions not covered by previous work. An important scenario which has not been previously calculated involves cycle operation for a Sodium-Cooled Fast Reactor (SFR) following a reactor scram event and the transition to the primary coolant natural circulation and decay heat removal. The Argonne National Laboratory (ANL) Plant Dynamics Code has been applied to investigate the dynamic behavior of the 96 MWe (250 MWt) Advanced Burner Test Reactor (ABTR) S-CO{sub 2} Brayton cycle following scram. The timescale for the primary sodium flowrate to coast down and the transition to natural circulation to occur was calculated with the SAS4A/SASSYS-1 computer code and found to be about 400 seconds. It is assumed that after this time, decay heat is removed by the normal ABTR shutdown heat removal system incorporating a dedicated shutdown heat removal S-CO{sub 2} pump and cooler. The ANL Plant Dynamics Code configured for the Small Secure Transportable Autonomous Reactor (SSTAR) Lead-Cooled Fast Reactor (LFR) was utilized to model the S-CO{sub 2} Brayton cycle with a decaying liquid metal coolant flow to the Pb-to-CO{sub 2} heat exchangers and temperatures reflecting the decaying core power and heat removal by the cycle. The results obtained in this manner are approximate but indicative of the cycle transient performance. The ANL Plant Dynamics Code calculations show that the S-CO{sub 2} cycle can operate for about 400 seconds following the reactor scram driven by the thermal energy stored in the reactor structures and coolant such that heat removal from the reactor exceeds the decay heat generation. Based on the results, requirements for the shutdown heat removal system may be defined

  1. Overview of recent studies and modifications being made to RHIC to mitigate the effects of a potential failure to the helium distribution system

    SciTech Connect

    Tuozzolo, J.; Bruno, D.; DiLieto, A.; Heppner, G.; Karol, R.; Lessard,E.; Liaw, C-J; McIntyre, G; Mi, C.; Reich, J.; Sandberg, J.; Seberg, S.; Smart, L.; Tallerico, T.; Theisen, C.; Todd, R.; Zapasek R.

    2011-03-28

    In order to cool the superconducting magnets in RHIC, its helium refrigerator distributes 4.5 K helium throughout the tunnel along with helium distribution for the magnet line recoolers, the heat shield, and the associated return lines. The worse case for failure would be a release from the magnet distribution line which operates at 3.5 to 4.5 atmospheres and contains the energized magnet but with a potential energy of 70 MJoules should the insulation system fail or an electrical connection opens. Studies were done to determine release rate of the helium and the resultant reduction in O{sub 2} concentration in the RHIC tunnel and service buildings. Equipment and components were also reviewed for design and reliability and modifications were made to reduce the likelihood of failure and to reduce the volume of helium that could be released.

  2. Fact #576: June 22, 2009 Carbon Dioxide from Gasoline and Diesel Fuel |

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Department of Energy 6: June 22, 2009 Carbon Dioxide from Gasoline and Diesel Fuel Fact #576: June 22, 2009 Carbon Dioxide from Gasoline and Diesel Fuel The amount of carbon dioxide released into the atmosphere by a vehicle is primarily determined by the carbon content of the fuel. However, there is a small portion of the fuel that is not oxidized into carbon dioxide when the fuel is burned. The Environmental Protection Agency (EPA) has published information on carbon dioxide emissions from

  3. Flow instabilities in non-uniformly heated helium jet arrays used for divertor PFCs

    DOE PAGES [OSTI]

    Youchison, Dennis L.

    2015-07-30

    In this study, due to a lack of prototypical experimental data, little is known about the off-normal behavior of recently proposed divertor jet cooling concepts. This article describes a computational fluid dynamics (CFD) study on two jet array designs to investigate their susceptibility to parallel flow instabilities induced by non-uniform heating and large increases in the helium outlet temperature. The study compared a single 25-jet helium-cooled modular divertor (HEMJ) thimble and a micro-jet array with 116 jets. Both have pure tungsten armor and a total mass flow rate of 10 g/s at a 600 °C inlet temperature. We investigated flowmore » perturbations caused by a 30 MW/m2 off-normal heat flux applied over a 25 mm2 area in addition to the nominal 5 MW/m2 applied over a 75 mm2 portion of the face. The micro-jet array exhibited lower temperatures and a more uniform surface temperature distribution than the HEMJ thimble. We also investigated the response of a manifolded nine-finger HEMJ assembly using the nominal heat flux and a 274 mm2 heated area. For the 30 MW/m2 case, the micro-jet array absorbed 750 W in the helium with a maximum armor surface temperature of 1280 °C and a fluid/solid interface temperature of 801 °C. The HEMJ absorbed 750 W with a maximum armor surface temperature of 1411 °C and a fluid/solid interface temperature of 844 °C. For comparison, both the single HEMJ finger and the micro-jet array used 5-mm-thick tungsten armor. The ratio of maximum to average temperature and variations in the local heat transfer coefficient were lower for the micro-jet array compared to the HEMJ device. Although high heat flux testing is required to validate the results obtained in these simulations, the results provide important guidance in jet design and manifolding to increase heat removal while providing more even temperature distribution and minimizing non-uniformity in the gas flow and thermal stresses at the armor joint.« less

  4. Flow instabilities in non-uniformly heated helium jet arrays used for divertor PFCs

    SciTech Connect

    Youchison, Dennis L.

    2015-07-30

    In this study, due to a lack of prototypical experimental data, little is known about the off-normal behavior of recently proposed divertor jet cooling concepts. This article describes a computational fluid dynamics (CFD) study on two jet array designs to investigate their susceptibility to parallel flow instabilities induced by non-uniform heating and large increases in the helium outlet temperature. The study compared a single 25-jet helium-cooled modular divertor (HEMJ) thimble and a micro-jet array with 116 jets. Both have pure tungsten armor and a total mass flow rate of 10 g/s at a 600 °C inlet temperature. We investigated flow perturbations caused by a 30 MW/m2 off-normal heat flux applied over a 25 mm2 area in addition to the nominal 5 MW/m2 applied over a 75 mm2 portion of the face. The micro-jet array exhibited lower temperatures and a more uniform surface temperature distribution than the HEMJ thimble. We also investigated the response of a manifolded nine-finger HEMJ assembly using the nominal heat flux and a 274 mm2 heated area. For the 30 MW/m2 case, the micro-jet array absorbed 750 W in the helium with a maximum armor surface temperature of 1280 °C and a fluid/solid interface temperature of 801 °C. The HEMJ absorbed 750 W with a maximum armor surface temperature of 1411 °C and a fluid/solid interface temperature of 844 °C. For comparison, both the single HEMJ finger and the micro-jet array used 5-mm-thick tungsten armor. The ratio of maximum to average temperature and variations in the local heat transfer coefficient were lower for the micro-jet array compared to the HEMJ device. Although high heat flux testing is required to validate the results obtained in these simulations, the results provide important guidance in jet design and manifolding to increase heat removal while providing more even temperature distribution and minimizing non-uniformity in the gas flow and thermal stresses at the

  5. Method and means of reducing erosion of components of plasma devices exposed to helium and hydrogen isotope radiation

    DOEpatents

    Kaminsky, Manfred S.; Das, Santosh K.; Rossing, Thomas D.

    1977-01-25

    Surfaces of components of plasma devices exposed to radiation by atoms or ions of helium or isotopes of hydrogen can be protected from damage due to blistering by shielding the surfaces with a structure formed by sintering a powder of aluminum or beryllium and its oxide or by coating the surfaces with such a sintered metal powder.

  6. The Helium Cooling System and Cold Mass Support System for theMICE Coupling Solenoid

    SciTech Connect

    Wang, L.; Wu, H.; Li, L.K.; Green, M.A.; Liu, C.S.; Li, L.Y.; Jia, L.X.; Virostek, S.P.

    2007-08-27

    The MICE cooling channel consists of alternating threeabsorber focus coil module (AFC) and two RF coupling coil module (RFCC)where the process of muon cooling and reacceleration occurs. The RFCCmodule comprises a superconducting coupling solenoid mounted around fourconventional conducting 201.25 MHz closed RF cavities and producing up to2.2T magnetic field on the centerline. The coupling coil magnetic fieldis to produce a low muon beam beta function in order to keep the beamwithin the RF cavities. The magnet is to be built using commercialniobium titanium MRI conductors and cooled by pulse tube coolers thatproduce 1.5 W of cooling capacity at 4.2 K each. A self-centering supportsystem is applied for the coupling magnet cold mass support, which isdesigned to carry a longitudinal force up to 500 kN. This report willdescribe the updated design for the MICE coupling magnet. The cold masssupport system and helium cooling system are discussed indetail.

  7. A modified heat leak test facility employing a closed-cycle helium refrigerator

    SciTech Connect

    Boroski, W.N.

    1996-01-01

    A Heat Leak Test Facility (HLTF) has been in use at Fermilab for many years. The apparatus has successfully measured the thermal performance of a variety of cryostat components under simulated operating conditions. While an effective tool in the cryostat design process, the HLTF has several limitations. Temperatures are normally fixed at cryogen boiling points and run times are limited to cryogen inventory. Moreover, close personnel attention is required to maintain system inventories and sustain system equilibrium. To provide longer measurement periods without perturbation and to minimize personnel interaction, a new heat leak measurement facility (HLTF-2) has been designed that incorporates a closed-cycle helium refrigerator. The two-stage refrigerator provides cooling to the various temperature stations of the HLTF while eliminating the need for cryogens. Eliminating cryogen inventories has resulted in a reduction of the amount of direct personnel attention required.

  8. Numerical investigation of pulse-modulated atmospheric radio frequency discharges in helium under different duty cycles

    SciTech Connect

    Sun Jizhong; Ding Zhengfen; Li Xuechun; Wang Dezhen [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116023 (China); Wang Qi [Dalian Institute of Semiconductor Technology, School of Electronics Science and Technology, Dalian University of Technology, Dalian 116023 (China)

    2011-12-15

    Experiments observed that the pulse duty cycle has effects on the plasma homogeneity in pulse-modulated radio frequency (rf) discharges. In this paper, pulse-modulated rf (13.56 MHz) helium discharges are theoretically investigated using a two dimensional fluid model. With the pulse period being fixed to 15 {mu}s, it is found that when the pulse-on duration is over 4 {mu}s, i.e., the duty cycle is larger than approximately 27%, the discharge transits from an inhomogeneous to a homogeneous mode in every specific part of each pulse cycle under currently-used simulation parameters. More quantitative analysis shows that the discharge becomes more homogeneous as the duty cycle is increased but does not reach complete homogeneity. Possible reasons for the homogeneity improvement are discussed.

  9. Corrosion and Creep of Candidate Alloys in High Temperature Helium and Steam Environments for the NGNP

    SciTech Connect

    Was, Gary; Jones, J. W.

    2013-06-21

    This project aims to understand the processes by which candidate materials degrade in He and supercritical water/steam environments characteristic of the current NGNP design. We will focus on understanding the roles of temperature, and carbon and oxygen potential in the 750-850 degree C range on both uniform oxidation and selective internal oxidation along grain boundaries in alloys 617 and 800H in supercritical water in the temperature range 500-600 degree C; and examining the application of static and cyclic stresses in combination with impure He environments in the temperature rang 750-850 degree C; and examining the application of static and cyclic stresses in combination with impure He environments in the temperature range 750-850 degree C over a range of oxygen and carbon potentials in helium. Combined, these studies wil elucidate the potential high damage rate processes in environments and alloys relevant to the NGNP.

  10. Patterned Exfoliation of GaAs Based on Masked Helium Implantation and Subsequent Rapid Thermal Annealing

    SciTech Connect

    Woo, H. J.; Choi, H. W.; Kim, G. D.; Hong, W.; Kim, J. K.

    2009-03-10

    A method of patterning single crystal GaAs based on ion implantation induced selective area exfoliation is suggested. Samples were implanted with 200-500 keV helium ions to a fluence range of 2-4x10{sup 16} He{sup +}/cm{sup 2} at room temperature through masks of Ni mesh (40 {mu}m opening) or stainless steel wire (50 {mu}m in diameter), and subsequent rapid thermal annealing at 350-500{open_square} resulted in expulsion of ion beam exposed material. The influences of ion energy, ion fluence, implantation temperature, subsequent annealing conditions (temperature and ramp rate), and mask pattern and its orientation with GaAs lattice on the patterned exfoliation were examined.

  11. Impurity gettering in silicon using cavities formed by helium implantation and annealing

    DOEpatents

    Myers, S.M. Jr.; Bishop, D.M.; Follstaedt, D.M.

    1998-11-24

    Impurity gettering in silicon wafers is achieved by a new process consisting of helium ion implantation followed by annealing. This treatment creates cavities whose internal surfaces are highly chemically reactive due to the presence of numerous silicon dangling bonds. For two representative transition-metal impurities, copper and nickel, the binding energies at cavities were demonstrated to be larger than the binding energies in precipitates of metal silicide, which constitutes the basis of most current impurity gettering. As a result the residual concentration of such impurities after cavity gettering is smaller by several orders of magnitude than after precipitation gettering. Additionally, cavity gettering is effective regardless of the starting impurity concentration in the wafer, whereas precipitation gettering ceases when the impurity concentration reaches a characteristic solubility determined by the equilibrium phase diagram of the silicon-metal system. The strong cavity gettering was shown to induce dissolution of metal-silicide particles from the opposite side of a wafer. 4 figs.

  12. Impurity gettering in silicon using cavities formed by helium implantation and annealing

    DOEpatents

    Myers, Jr., Samuel M.; Bishop, Dawn M.; Follstaedt, David M.

    1998-01-01

    Impurity gettering in silicon wafers is achieved by a new process consisting of helium ion implantation followed by annealing. This treatment creates cavities whose internal surfaces are highly chemically reactive due to the presence of numerous silicon dangling bonds. For two representative transition-metal impurities, copper and nickel, the binding energies at cavities were demonstrated to be larger than the binding energies in precipitates of metal silicide, which constitutes the basis of most current impurity gettering. As a result the residual concentration of such impurities after cavity gettering is smaller by several orders of magnitude than after precipitation gettering. Additionally, cavity gettering is effective regardless of the starting impurity concentration in the wafer, whereas precipitation gettering ceases when the impurity concentration reaches a characteristic solubility determined by the equilibrium phase diagram of the silicon-metal system. The strong cavity gettering was shown to induce dissolution of metal-silicide particles from the opposite side of a wafer.

  13. Electron dynamics and plasma jet formation in a helium atmospheric pressure dielectric barrier discharge jet

    SciTech Connect

    Algwari, Q. Th.; O'Connell, D.

    2011-09-19

    The excitation dynamics within the main plasma production region and the plasma jets of a kHz atmospheric pressure dielectric barrier discharge (DBD) jet operated in helium was investigated. Within the dielectric tube, the plasma ignites as a streamer-type discharge. Plasma jets are emitted from both the powered and grounded electrode end; their dynamics are compared and contrasted. Ignition of these jets are quite different; the jet emitted from the powered electrode is ignited with a slight time delay to plasma ignition inside the dielectric tube, while breakdown of the jet at the grounded electrode end is from charging of the dielectric and is therefore dependent on plasma production and transport within the dielectric tube. Present streamer theories can explain these dynamics.

  14. First Principles Calculations of Helium Solution Energies in BCC Transition Metals

    SciTech Connect

    Willaime, Francois; Fu, Chu Chun

    2008-07-01

    Density functional theory calculations of the solution energies of helium in substitutional, tetrahedral and octahedral sites have been performed for all BCC transition metals: V, Nb, Ta, Cr, Mo, W and Fe. The effects of exchange correlation functional and of pseudopotential have been investigated in Fe; they are relatively small. The solution energies are found to be weakly dependent on the element for the substitutional site whereas for the interstitial sites they are much smaller in group V than in group VI and they decrease from 3d to 4d and 5d metals. As a result an inversion is observed from V, Nb and Ta - which tend to favor the interstitial site - to Mo and W, which favor the substitutional one, with an intermediate behavior for Cr and Fe. Finally, the results indicate that the tetrahedral site is always energetically more favorable than the octahedral one by 0.2 to 0.3 eV. (authors)

  15. High-voltage electrical apparatus utilizing an insulating gas of sulfur hexafluoride and helium

    DOEpatents

    Wootton, Roy E.

    1980-01-01

    High-voltage electrical apparatus includes an outer housing at low potential, an inner electrode disposed within the outer housing at high potential with respect thereto, and support means for insulatably supporting the inner electrode within the outer housing. Conducting particles contaminate the interior of the outer housing, and an insulating gas electrically insulates the inner electrode from the outer housing even in the presence of the conducting particles. The insulating gas is comprised of sulfur hexafluoride at a partial pressure of from about 2.9 to about 3.4 atmospheres absolute, and helium at a partial pressure from about 1.1 to about 11.4 atmospheres absolute. The sulfur hexafluoride comprises between 20 and 65 volume percent of the insulating gas.

  16. Nanoforging Single Layer MoSe2 Through Defect Engineering with Focused Helium Ion Beams

    DOE PAGES [OSTI]

    Iberi, Vighter; Liang, Liangbo; Ievlev, Anton V.; Stanford, Michael G.; Lin, Ming-Wei; Li, Xufan; Mahjouri-Samani, Masoud; Jesse, Stephen; Sumpter, Bobby G.; Kalinin, Sergei V.; et al

    2016-08-02

    Development of devices and structures based on the layered 2D materials critically hinges on the capability to induce, control, and tailor the electronic, transport, and optoelectronic properties via defect engineering, much like doping strategies have enabled semiconductor electronics and forging enabled introduction of iron age. Here, we demonstrate the use of a scanning helium ion microscope (HIM) for tailoring the functionality of single layer MoSe2 locally, and decipher associated mechanisms at atomic level. We demonstrate He+ beam bombardment that locally creates vacancies, shifts the Fermi energy landscape and thereby increases the Young s modulus of elasticity. Furthermore, we observe formore » the first time, an increase in the B-exciton photoluminescence signal from the nanoforged regions at room temperature. In conclusion, the approach for precise defect engineering demonstrated here opens opportunities for creating functional 2D optoelectronic devices with a wide range of customizable properties that include operating in the visible region.« less

  17. Effect of helium addition on discharge characteristics in a flat fluorescent lamp

    SciTech Connect

    Lee, Seong-Eui; Lee, Ho-Nyeon; Park, Hyoung-Bin; Lee, Kyo Sung; Choi, Kyung Cheol

    2005-11-01

    The discharge characteristics of a multielectrode dual coplanar in a mercury-free flat fluorescent lamp were investigated using brightness-efficiency measurement and the infrared (IR) spectrum and intensified charge coupled device (ICCD) characteristics. The level of brightness was above 14 900 cd/m{sup 2} under the conditions of neon--50% xenon-8% He gas composition, 150 Torr pressure, and 20 kHz alternating current pulse. The ICCD results revealed a faster and wider discharge with a Ne-50% Xe-8% He gas composition. The effect of adding helium (He) to Ne-50% Xe revealed a faster peak emission, as confirmed by ICCD images. From the gated IR emission spectrum, the intensity ratio of I{sub 823nm}/I{sub 828nm} was {approx}8% higher with Ne-50% Xe-8% He than with Ne-50% Xe under the same pressure and applied voltage conditions.

  18. Engineering the Big Chill: The story of JLab’s Central Helium Liquefier

    SciTech Connect

    Westfall, Catherine

    2014-03-29

    This article tells the story of the Central Helium Liquefier (CHL) at the Thomas Jefferson National Accelerator Facility (JLab), one of the US National Laboratories. JLab’s successful superconducting radio frequency accelerator was only possible because a group of JLab engineers successfully tackled a complex of difficulties to build a cryogenic system that included the CHL, a task that required advancing the frontier of cryogenic technology. Ultimately, these cryogenic advances were applied far beyond JLab to the benefit of cutting-edge programs at other US national laboratories (Oak Ridge, Brookhaven, and the Facility for Rare Isotope Beams at MSU) as well as NASA. In addition, this innovation story dramatizes the sort of engineer-driven technological problem solving that allows the successful launch and operation of experimental projects. Along the way, the CHL story also provides an important addition to our understanding of the role played by engineers and industry in creating knowledge at physics laboratories.

  19. Commissioning and operational results of the 12 GeV helium compression system at Jlab

    SciTech Connect

    Knudsen, Peter N.; Ganni, Venkatarao; Dixon, Kelly D.; Norton, Robert O.; Creel, Jonathan D.

    2015-12-01

    The new compressor system at Jefferson Lab (JLab) for the 12 GeV upgrade was commissioned in the spring of 2013 and incorporates many design changes, discussed in previous publications, to improve the operational range, efficiency, reliability and maintainability as compared to previous compressor skids used for this application. The 12 GeV helium compression system has five compressors configured with four pressure levels supporting three pressure levels in the new cold box. During compressor commissioning the compressors were operated independent of the cold box over a wide range of process conditions to verify proper performance including adequate cooling and oil removal. Isothermal and volumetric efficiencies over these process conditions for several built-involume ratios were obtained. This paper will discuss the operational envelope results and the modifications/improvements incorporated into the skids.

  20. Comparison of classical and quantal calculations of helium three-body recombination

    SciTech Connect

    Prez-Ros, Jess Greene, Chris H.; Ragole, Steve; Wang, Jia

    2014-01-28

    A general method to study classical scattering in n-dimension is developed. Through classical trajectory calculations, the three-body recombination is computed as a function of the collision energy for helium atoms, as an example. Quantum calculations are also performed for the J{sup ?} = 0{sup +} symmetry of the three-body recombination rate in order to compare with the classical results, yielding good agreement for E ? 1 K. The classical threshold law is derived and numerically confirmed for the Newtonian three-body recombination rate. Finally, a relationship is found between the quantum and classical three-body hard hypersphere elastic cross sections which is analogous to the well-known shadow scattering in two-body collisions.

  1. Fast Thermal Helium Beam diagnostic for measurements of edge electron profiles and fluctuations

    SciTech Connect

    Agostini, M. Scarin, P.; Cavazzana, R.; Carraro, L.; Grando, L.; Taliercio, C.; Franchin, L.; Tiso, A.

    2015-12-15

    The edge of fusion experiments is a region where strong gradients develop, together with the presence of strong fluctuations due to turbulence. The thermal helium beam diagnostic developed for the RFX-mod experiment allows the measurements with a single diagnostic of both low frequency time evolution of the edge radial profiles of electron density and temperature (tens of hertz), and the high frequency fluctuations (hundreds of kHz). To maximize the collected light, the three HeI lines necessary to be measured for the evaluation of n{sub e} and T{sub e} are separated with a spectrograph, and multianode photomultipliers are used as light detectors. The paper describes the diagnostic setup, with the interface hardware with the machine and the optical layout, and the characterization of its performances.

  2. Actinide Dioxides in Water: Interactions at the Interface

    SciTech Connect

    Alexandrov, Vitaly; Shvareva, Tatiana Y.; Hayun, Shmuel; Asta, Mark; Navrotsky, Alexandra

    2011-12-15

    A comprehensive understanding of chemical interactions between water and actinide dioxide surfaces is critical for safe operation and storage of nuclear fuels. Despite substantial previous research, understanding the nature of these interactions remains incomplete. In this work, we combine accurate calorimetric measurements with first-principles computational studies to characterize surface energies and adsorption enthalpies of water on two fluorite-structured compounds, ThO? and CeO?, that are relevant for understanding the behavior of water on actinide oxide surfaces more generally. We determine coverage-dependent adsorption enthalpies and demonstrate a mixed molecular and dissociative structure for the first hydration layer. The results show a correlation between the magnitude of the anhydrous surface energy and the water adsorption enthalpy. Further, they suggest a structural model featuring one adsorbed water molecule per one surface cation on the most stable facet that is expected to be a common structural signature of water adsorbed on actinide dioxide compounds.

  3. Regenerable immobilized aminosilane sorbents for carbon dioxide capture applications

    DOEpatents

    Gay, McMahan; Choi, Sunho; Jones, Christopher W

    2014-09-16

    A method for the separation of carbon dioxide from ambient air and flue gases is provided wherein a phase separating moiety with a second moiety are simultaneously coupled and bonded onto an inert substrate to create a mixture which is subsequently contacted with flue gases or ambient air. The phase-separating moiety is an amine whereas the second moiety is an aminosilane, or a Group 4 propoxide such as titanium (IV) propoxide (tetrapropyl orthotitanate, C.sub.12H.sub.28O.sub.4Ti). The second moiety makes the phase-separating moiety insoluble in the pores of the inert substrate. The new sorbents have a high carbon dioxide loading capacity and considerable stability over hundreds of cycles. The synthesis method is readily scalable for commercial and industrial production.

  4. Historical Sulfur Dioxide Emissions 1850-2000: Methods and Results

    SciTech Connect

    Smith, Steven J.; Andres, Robert; Conception , Elvira; Lurz, Joshua

    2004-01-25

    A global, self-consistent estimate of sulfur dioxide emissions over the last one and a half century were estimated by using a combination of bottom-up and best available inventory methods including all anthropogenic sources. We find that global sulfur dioxide emissions peaked about 1980 and have generally declined since this time. Emissions were extrapolated to a 1{sup o} x 1{sup o} grid for the time period 1850-2000 at annual resolution with two emission height levels and by season. Emissions are somewhat higher in the recent past in this new work as compared with some comprehensive estimates. This difference is largely due to our use of emissions factors that vary with time to account for sulfur removals from fossil fuels and industrial smelting processes.

  5. Application Of Optical Processing For Growth Of Silicon Dioxide

    DOEpatents

    Sopori, Bhushan L.

    1997-06-17

    A process for producing a silicon dioxide film on a surface of a silicon substrate. The process comprises illuminating a silicon substrate in a substantially pure oxygen atmosphere with a broad spectrum of visible and infrared light at an optical power density of from about 3 watts/cm.sup.2 to about 6 watts/cm.sup.2 for a time period sufficient to produce a silicon dioxide film on the surface of the silicon substrate. An optimum optical power density is about 4 watts/cm.sup.2 for growth of a 100.ANG.-300.ANG. film at a resultant temperature of about 400.degree. C. Deep level transient spectroscopy analysis detects no measurable impurities introduced into the silicon substrate during silicon oxide production and shows the interface state density at the SiO.sub.2 /Si interface to be very low.

  6. Application of optical processing for growth of silicon dioxide

    DOEpatents

    Sopori, B.L.

    1997-06-17

    A process for producing a silicon dioxide film on a surface of a silicon substrate is disclosed. The process comprises illuminating a silicon substrate in a substantially pure oxygen atmosphere with a broad spectrum of visible and infrared light at an optical power density of from about 3 watts/cm{sup 2} to about 6 watts/cm{sup 2} for a time period sufficient to produce a silicon dioxide film on the surface of the silicon substrate. An optimum optical power density is about 4 watts/cm{sup 2} for growth of a 100{angstrom}-300{angstrom} film at a resultant temperature of about 400 C. Deep level transient spectroscopy analysis detects no measurable impurities introduced into the silicon substrate during silicon oxide production and shows the interface state density at the SiO{sub 2}/Si interface to be very low. 1 fig.

  7. Transient analysis of an FHR coupled to a helium Brayton power cycle

    SciTech Connect

    Chen, Minghui; Kim, In Hun; Sun, Xiaodong; Christensen, Richard; Utgikar, Vivek; Sabharwall, Piyush

    2015-08-01

    The Fluoride salt-cooled High-temperature Reactor (FHR) features a passive decay heat removal system and a high-efficiency Brayton cycle for electricity generation. It typically employs an intermediate loop, consisting of an intermediate heat exchanger (IHX) and a secondary heat exchanger (SHX), to couple the primary system with the power conversion unit (PCU). In this study, a preliminary dynamic system model is developed to simulate transient characteristics of a prototypic 20-MWth Fluoride salt-cooled High-temperature Test Reactor (FHTR). The model consists of a series of differential conservation equations that are numerically solved using the MATLAB platform. For the reactor, a point neutron kinetics model is adopted. For the IHX and SHX, a fluted tube heat exchanger and an offset strip-fin heat exchanger are selected, respectively. Detailed geometric parameters of each component in the FHTR are determined based on the FHTR nominal steady-state operating conditions. Three initiating events are simulated in this study, including a positive reactivity insertion, a step increase in the mass flow rate of the PCU helium flow, and a step increase in the PCU helium inlet temperature to the SHX. The simulation results show that the reactor has inherent safety features for those three simulated scenarios. It is observed that the increase in the temperatures of the fuel pebbles and primary coolant is mitigated by the decrease in the reactor power due to negative temperature feedbacks. The results also indicate that the intermediate loop with the two heat exchangers plays a significant role in the transient progression of the integral reactor system.

  8. Investigating the dynamics of laser induced sparks in atmospheric helium using Rayleigh and Thomson scattering

    SciTech Connect

    Nedanovska, E.; Nersisyan, G.; Lewis, C. L. S.; Riley, D.; Graham, W. G.; Morgan, T. J.; Hüwel, L.; Murakami, T.

    2015-01-07

    We have used optical Rayleigh and Thomson scattering to investigate the expansion dynamics of laser induced plasma in atmospheric helium and to map its electron parameters both in time and space. The plasma is created using 9 ns duration, 140 mJ pulses from a Nd:YAG laser operating at 1064 nm, focused with a 10 cm focal length lens, and probed with 7 ns, 80 mJ, and 532 nm Nd:YAG laser pulses. Between 0.4 μs and 22.5 μs after breakdown, the electron density decreases from 3.3 × 10{sup 17 }cm{sup −3} to 9 × 10{sup 13 }cm{sup −3}, while the temperature drops from 3.2 eV to 0.1 eV. Spatially resolved Thomson scattering data recorded up to 17.5 μs reveal that during this time the laser induced plasma expands at a rate given by R ∼ t{sup 0.4} consistent with a non-radiative spherical blast wave. This data also indicate the development of a toroidal structure in the lateral profile of both electron temperature and density. Rayleigh scattering data show that the gas density decreases in the center of the expanding plasma with a central scattering peak reemerging after about 12 μs. We have utilized a zero dimensional kinetic global model to identify the dominant particle species versus delay time and this indicates that metastable helium and the He{sub 2}{sup +} molecular ion play an important role.

  9. Solvation of molecules in superfluid helium enhances the interaction induced localization effect

    SciTech Connect

    Walewski, ?ukasz Forbert, Harald; Marx, Dominik

    2014-04-14

    Atomic nuclei become delocalized at low temperatures as a result of quantum effects, whereas they are point-like in the high temperature (classical) limit. For non-interacting nuclei, the delocalization upon lowering the temperature is quantitatively described in terms of the thermal de Broglie wavelength of free particles. Clearly, light non-interacting nuclei the proton being a prominent one are much more delocalized at low temperatures compared to heavy nuclei, such as non-interacting oxygen having water in mind. However, strong interactions due to chemical bonding in conjunction with ultra-low temperatures characteristic to superfluid helium nanodroplets change this common picture substantially for nuclei in molecules or clusters. It turns out that protons shared in hydrogen bonds undergo an extreme interaction induced localization at temperatures on the order of 1 K, which compresses the protonic spatial distributions to the size of the much heavier donor or acceptor atoms, such as O or Cl nuclei, corresponding to about 0.1% of the volume occupied by a non-interacting proton at the same temperature. Moreover, applying our recently developed hybrid ab initio path integral molecular dynamics/bosonic path integral Monte Carlo quantum simulation technique to a HCl/water cluster, HCl(H{sub 2}O){sub 4}, we find that helium solvation has a significant additional localizing effect of up to about 30% in volume. In particular, the solvent-induced excess localization is the stronger the lesser the given nucleus is already localized in the gas phase reference situation.

  10. Catalyst for the reduction of sulfur dioxide to elemental sulfur

    DOEpatents

    Jin, Yun; Yu, Qiquan; Chang, Shih-Ger

    1996-01-01

    The inventive catalysts allow for the reduction of sulfur dioxide to elemental sulfur in smokestack scrubber environments. The catalysts have a very high sulfur yield of over 90% and space velocity of 10,000 h.sup.-1. They also have the capacity to convert waste gases generated during the initial conversion into elemental sulfur. The catalysts have inexpensive components, and are inexpensive to produce. The net impact of the invention is to make this technology practically available to industrial applications.

  11. Titanium dioxide, single-walled carbon nanotube composites

    DOEpatents

    Yao, Yuan; Li, Gonghu; Gray, Kimberly; Lueptow, Richard M.

    2015-07-14

    The present invention provides titanium dioxide/single-walled carbon nanotube composites (TiO.sub.2/SWCNTs), articles of manufacture, and methods of making and using such composites. In certain embodiments, the present invention provides membrane filters and ceramic articles that are coated with TiO.sub.2/SWCNT composite material. In other embodiments, the present invention provides methods of using TiO.sub.2/SWCNT composite material to purify a sample, such as a water or air sample.

  12. Chapter 4: Advancing Clean Electric Power Technologies | Carbon Dioxide and Storage Value-Added Options Technology Assessment

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Storage Value-Added Options Carbon Dioxide Capture for Natural Gas and Industrial Applications Carbon Dioxide Capture Technologies Carbon Dioxide Storage Technologies Crosscutting Technologies in Carbon Dioxide Capture and Storage Fast-spectrum Reactors Geothermal Power High Temperature Reactors Hybrid Nuclear-Renewable Energy Systems Hydropower Light Water Reactors Marine and Hydrokinetic Power Nuclear Fuel Cycles Solar Power Stationary Fuel Cells Supercritical Carbon Dioxide Brayton Cycle

  13. Separation of Carbon Dioxide from Flue Gas Using Ion Pumping

    SciTech Connect

    Aines, R; Bourcier, W L; Johnson, M R

    2006-04-21

    We are developing a new way of separating carbon dioxide from flue gas based on ionic pumping of carbonate ions dissolved in water. Instead of relying on large temperature or pressure changes to remove carbon dioxide from solvent used to absorb it from flue gas, the ion pump increases the concentration of dissolved carbonate ion in solution. This increases the overlying vapor pressure of carbon dioxide gas, which can be removed from the downstream side of the ion pump as a nearly pure gas. This novel approach to increasing the concentration of the extracted gas permits new approaches to treating flue gas. The slightly basic water used as the extraction medium is impervious to trace acid gases that destroy existing solvents, and no pre-separation is necessary. The simple, robust nature of the process lends itself to small separation plants. Although the energy cost of the ion pump is significant, we anticipate that it will be compete favorably with the current 35% energy penalty of chemical stripping systems in use at power plants. There is the distinct possibility that this simple method could be significantly more efficient than existing processes.

  14. Utilizing the market to control sulfur dioxide emissions

    SciTech Connect

    Loeher, C.F. III

    1995-12-01

    Environmental policy in the United States is evolving; command and control approaches are being slowly replaced with market-based incentives. Market-based regulation is favorable because it provides the regulated community with flexibility in choosing between pollution control options. A recent application of a market-based approach is Title IV of the 1990 Clean Air Act Amendments. This paper evaluates the advantages of utilizing market-based incentives to control sulfur dioxide emissions. The evaluation embodies an extensive methodology, which provides an overview of the policy governing air quality, discusses pollution control philosophies and analyzes their associated advantages and limitations. Further, it describes the development and operation of a market for emissions trading, impediments to the market, and recommends strategies to improve the market. The evaluation concludes by analyzing the results of five empirical simulations demonstrating the cost-effectiveness of employing market-based incentives versus command-and-control regulation for controlling sulfur dioxide emissions. The results of the evaluation indicate that regulatory barriers and market impediments have inhibited allowance trading. However, many of these obstacles have been or are being eliminated through Federal and state regulations, and through enhancement of the market. Results also demonstrate that sulfur dioxide allowance trading can obtain identical levels of environmental protection as command-and-control approaches while realizing cost savings to government and industry.

  15. CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS

    SciTech Connect

    David A. Green; Brian S. Turk; Jeffrey W. Portzer; Raghubir P. Gupta; William J. McMichael; Ya Liang; Tyler Moore; Douglas P. Harrison

    2003-08-01

    This report describes research conducted between April 1, 2003 and June 30, 2003 on the use of dry regenerable sorbents for concentration of carbon dioxide from flue gas. Grade 1 sodium bicarbonate performed similarly to grade 5 sodium bicarbonate in fixed bed testing in that activity improved after the first carbonation cycle and did not decline over the course of 5 cycles. Thermogravimetric analysis indicated that sodium bicarbonate sorbents produced by calcination of sodium bicarbonate are superior to either soda ash or calcined trona. Energy requirements for regeneration of carbon dioxide sorbents (either wet or dry) is of primary importance in establishing the economic feasibility of carbon dioxide capture processes. Recent studies of liquid amine sorption processes were reviewed and found to incorporate conflicting assumptions of energy requirements. Dry sodium based processes have the potential to be less energy intensive and thus less expensive than oxygen inhibited amine based systems. For dry supported sorbents, maximizing the active fraction of the sorbent is of primary importance in developing an economically feasible process.

  16. Trapping helium in Y{sub 2}Ti{sub 2}O{sub 7} compared to in matrix iron: A first principles study

    SciTech Connect

    Yang, Litong; Jiang, Yong E-mail: odette@engineering.ucsb.edu; Robert Odette, G. E-mail: odette@engineering.ucsb.edu; Yamamoto, Takuya; Liu, Zuming; Liu, Yong

    2014-04-14

    Pyrochlore Y{sub 2}Ti{sub 2}O{sub 7} is a primary precipitate phase in nano-structured ferritic alloys (NFAs) for fission and fusion energy applications. We report a theoretical study for assessing the relative stability of trapping helium in Y{sub 2}Ti{sub 2}O{sub 7} versus in matrix iron. Various defect structures and the associated energies are examined and compared. Results reveal that helium can be deeply trapped in Y{sub 2}Ti{sub 2}O{sub 7} and that the corresponding self-interaction is essentially repulsive. Transmutant helium in NFAs prefers to occupy individual octa-interstitial sites in Y{sub 2}Ti{sub 2}O{sub 7}, before forming small clusters in Y{sub 2}Ti{sub 2}O{sub 7}. Helium partitioning in NFAs depends on the number and dispersion of Y{sub 2}Ti{sub 2}O{sub 7}; and thus initially, bubble formation and growth in iron matrix can be largely suppressed. Charge transfer occurs from helium to neighboring oxygen anions, but not to neighboring metal cations, suggesting a general effectiveness of trapping helium in oxides. Reasons for the ultimate fate of helium to form small nm-scale interface bubbles are also discussed.

  17. Apparatus and method for removing solvent from carbon dioxide in resin recycling system

    DOEpatents

    Bohnert, George W.; Hand, Thomas E.; DeLaurentiis, Gary M.

    2009-01-06

    A two-step resin recycling system and method solvent that produces essentially contaminant-free synthetic resin material. The system and method includes one or more solvent wash vessels to expose resin particles to a solvent, the solvent contacting the resin particles in the one or more solvent wash vessels to substantially remove contaminants on the resin particles. A separator is provided to separate the solvent from the resin particles after removal from the one or more solvent wash vessels. The resin particles are next exposed to carbon dioxide in a closed loop carbon dioxide system. The closed loop system includes a carbon dioxide vessel where the carbon dioxide is exposed to the resin, substantially removing any residual solvent remaining on the resin particles after separation. A separation vessel is also provided to separate the solvent from the solvent laden carbon dioxide. Both the carbon dioxide and the solvent are reused after separation in the separation vessel.

  18. Impact of Light-Duty Vehicle Emissions on 21st Century Carbon Dioxide Concentrations

    SciTech Connect

    Smith, Steven J.; Kyle, G. Page

    2007-08-04

    The impact of light-duty passenger vehicle emissions on global carbon dioxide concentrations was estimated using the MAGICC reduced-form climate model combined with the PNNL contribution to the CCSP scenarios product. Our central estimate is that tailpipe light duty vehicle emissions of carbon-dioxide over the 21st century will increase global carbon dioxide concentrations by slightly over 12 ppmv by 2100.

  19. Projects Selected for Safe and Permanent Geologic Storage of Carbon Dioxide

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    | Department of Energy Selected for Safe and Permanent Geologic Storage of Carbon Dioxide Projects Selected for Safe and Permanent Geologic Storage of Carbon Dioxide August 6, 2014 - 11:00am Addthis Washington, D.C. - The U.S. Department of Energy (DOE) announced the selection of 13 projects to develop technologies and methodologies for geologic storage of carbon dioxide (CO2). Carbon capture and storage (CCS) research is focused on developing technologies to capture industrially generated

  20. Method of determining pH by the alkaline absorption of carbon dioxide

    DOEpatents

    Hobbs, David T.

    1992-01-01

    A method for measuring the concentration of hydroxides in alkaline solutions in a remote location using the tendency of hydroxides to absorb carbon dioxide. The method includes the passing of carbon dioxide over the surface of an alkaline solution in a remote tank before and after measurements of the carbon dioxide solution. A comparison of the measurements yields the absorption fraction from which the hydroxide concentration can be calculated using a correlation of hydroxide or pH to absorption fraction.

  1. A new leaf: Scientists turn carbon dioxide back into fuel | Argonne

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    National Laboratory Argonne postdoctoral researcher Cong Liu and chemists Larry Curtiss and Peter Zapol discuss their recent research results on converting carbon dioxide into usable fuel. Photo by Wes Agresta. Argonne postdoctoral researcher Cong Liu and chemists Larry Curtiss and Peter Zapol discuss their recent research results on converting carbon dioxide into usable fuel. Photo by Wes Agresta. A new leaf: Scientists turn carbon dioxide back into fuel July 29, 2016 Tweet EmailPrint As

  2. Chapter 4: Advancing Clean Electric Power Technologies | Carbon Dioxide Capture Technologies Technology Assessment

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Technologies Carbon Dioxide Storage Technologies Crosscutting Technologies in Carbon Dioxide Capture and Storage Fast-spectrum Reactors Geothermal Power High Temperature Reactors Hybrid Nuclear-Renewable Energy Systems Hydropower Light Water Reactors Marine and Hydrokinetic Power Nuclear Fuel Cycles Solar Power Stationary Fuel Cells Supercritical Carbon Dioxide Brayton Cycle Wind Power ENERGY U.S. DEPARTMENT OF Clean Power Quadrennial Technology Review 2015 1 Quadrennial Technology Review 2015

  3. Chapter 4: Advancing Clean Electric Power Technologies | Carbon Dioxide Storage Technologies Technology Assessment

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Technologies Crosscutting Technologies in Carbon Dioxide Capture and Storage Fast-spectrum Reactors Geothermal Power High Temperature Reactors Hybrid Nuclear-Renewable Energy Systems Hydropower Light Water Reactors Marine and Hydrokinetic Power Nuclear Fuel Cycles Solar Power Stationary Fuel Cells Supercritical Carbon Dioxide Brayton Cycle Wind Power ENERGY U.S. DEPARTMENT OF Clean Power Quadrennial Technology Review 2015 1 Quadrennial Technology Review 2015 Carbon Dioxide Storage Technologies

  4. Single and double resonance spectroscopy of methanol embedded in superfluid helium nanodroplets

    SciTech Connect

    Raston, Paul L.; Douberly, Gary E.; Jger, Wolfgang

    2014-07-28

    Methanol is one of the simplest molecules that undergo torsional oscillations, and so it has been extensively studied in the gas phase by various spectroscopic techniques. At 300 K, a large number of rotational, torsional, and vibrational energy levels is populated, and this makes for a rather complicated spectrum, which is still not fully understood. It is expected that in going from 300 K to 0.4 K (the temperature of helium nanodroplets) the population distribution of methanol will mainly collapse into two states; the J{sub K} = 0{sub 0} state for the A{sub 1} nuclear spin symmetry species (with I{sub CH{sub 3}} = 3/2), and the J{sub K} = 1{sub ?1} state for the E species (I{sub CH{sub 3}} = 1/2). This results in a simplified spectrum that consists of narrow a-type (?K = 0) lines and broader b- and c-type (?K = 1) lines. We have recorded the rotovibrational spectrum of CH{sub 3}OH in the OH stretching, CH{sub 3} stretching and bending, CH{sub 3} rocking, and CO stretching regions, and have firmly assigned five bands (v{sub 1}, v{sub 2}, v{sub 3}, v{sub 7}, and v{sub 8}), and tentatively assigned five others (v{sub 9}, 2v{sub 4}, v{sub 4} + v{sub 10}, 2v{sub 10}, and v{sub 4} + v{sub 5}). To our knowledge, the transitions we have assigned within the v{sub 4} + v{sub 10}, 2v{sub 10}, and v{sub 4} + v{sub 5} bands have not yet been assigned in the gas phase, and we hope that considering the very small matrix shift in helium nanodroplets (<1 cm{sup ?1} for most subband origins of CH{sub 3}OH), those made here can aid in their gas phase identification. Microwave-infrared double resonance spectroscopy was used to confirm the initially tentative a-type infrared assignments in the OH stretching (v{sub 1}) band of A{sub 1} species methanol, in addition to revealing warm b-type lines. From a rotovibrational analysis, the B rotational constant is found to be reduced quite significantly (56%) with respect to the gas phase, and the torsional tunneling splittings are

  5. Strong and Reversible Binding of Carbon Dioxide in a Green Metal...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Strong and Reversible Binding of Carbon Dioxide in a Green Metal-Organic Framework Previous Next List Jeremiah J. Gassensmith, Hiroyasu Furukawa, Ronald A. Smaldone, Ross S. ...

  6. Table 11.1 Carbon Dioxide Emissions From Energy Consumption by...

    Energy Information Administration (EIA) (indexed site)

    ... minus denaturant. 5Distillate fuel oil, excluding biodiesel. RRevised. PPreliminary. ... Notes: * Data are estimates for carbon dioxide emissions from energy consumption, ...

  7. Table 11.2e Carbon Dioxide Emissions From Energy Consumption...

    Energy Information Administration (EIA) (indexed site)

    ... from energy consumption. * See "Carbon Dioxide" in Glossary. * Totals may not equal sum of components due to independent rounding. 4Distillate fuel oil, excluding biodiesel. ...

  8. Table 11.2c Carbon Dioxide Emissions From Energy Consumption...

    Energy Information Administration (EIA) (indexed site)

    ... minus denaturant. 4Distillate fuel oil, excluding biodiesel. RRevised. PPreliminary. ... Notes: * Data are estimates for carbon dioxide emissions from energy consumption, ...

  9. Table 11.2a Carbon Dioxide Emissions From Energy Consumption...

    Energy Information Administration (EIA) (indexed site)

    ... from energy consumption. * See "Carbon Dioxide" in Glossary. * Totals may not equal sum of components due to independent rounding. 4Distillate fuel oil, excluding biodiesel. ...

  10. Table 11.2b Carbon Dioxide Emissions From Energy Consumption...

    Energy Information Administration (EIA) (indexed site)

    ... minus denaturant. 4Distillate fuel oil, excluding biodiesel. RRevised. PPreliminary. ... Notes: * Data are estimates for carbon dioxide emissions from energy consumption. * See ...

  11. Low-Cost, High-Accuracy, Whole-Building Carbon Dioxide Monitoring...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Lead Performer: Dioxide Materials(tm) - Boca Raton, FL Partner: I-SENSE at Florida ... Sensing and Embedded Network Systems Engineering (I-SENSE) at Florida Atlantic University. ...

  12. Fact #898: November 9, 2015 World Carbon Dioxide Emissions, 1990-2012 -

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Dataset | Department of Energy 8: November 9, 2015 World Carbon Dioxide Emissions, 1990-2012 - Dataset Fact #898: November 9, 2015 World Carbon Dioxide Emissions, 1990-2012 - Dataset Excel file and dataset for 2015 World Carbon Dioxide Emissions, 1990-2012 fotw#898_web.xlsx (25.25 KB) More Documents & Publications Fact #948: October 24, 2016 Carbon Dioxide Emissions from Transportation Exceeded those from the Electric Power Sector for the First Time in 38 Years - Dataset Enabling the

  13. Carbon ion pump for removal of carbon dioxide from combustion gas and other gas mixtures

    DOEpatents

    Aines, Roger D.; Bourcier, William L.

    2014-08-19

    A novel method and system of separating carbon dioxide from flue gas is introduced. Instead of relying on large temperature or pressure changes to remove carbon dioxide from a solvent used to absorb it from flue gas, the ion pump method, as disclosed herein, dramatically increases the concentration of dissolved carbonate ion in solution. This increases the overlying vapor pressure of carbon dioxide gas, permitting carbon dioxide to be removed from the downstream side of the ion pump as a pure gas. The ion pumping may be obtained from reverse osmosis, electrodialysis, thermal desalination methods, or an ion pump system having an oscillating flow in synchronization with an induced electric field.

  14. Carbon ion pump for removal of carbon dioxide from combustion gas and other gas mixtures

    DOEpatents

    Aines, Roger D.; Bourcier, William L.

    2010-11-09

    A novel method and system of separating carbon dioxide from flue gas is introduced. Instead of relying on large temperature or pressure changes to remove carbon dioxide from a solvent used to absorb it from flue gas, the ion pump method, as disclosed herein, dramatically increases the concentration of dissolved carbonate ion in solution. This increases the overlying vapor pressure of carbon dioxide gas, permitting carbon dioxide to be removed from the downstream side of the ion pump as a pure gas. The ion pumping may be obtained from reverse osmosis, electrodialysis, thermal desalination methods, or an ion pump system having an oscillating flow in synchronization with an induced electric field.

  15. METHOD OF DISSOLVING PLUTONIUM DIOXIDE IN NITRIC ACID USING CERIUM IONS

    DOEpatents

    Wilson, A.S.

    1961-10-24

    A method is descnibed for catalyzing the dissolution of plutenium dioxide in nitric acid with small amounts of cerium ions. (AEC)

  16. Two for the Price of One: Water and Carbon Dioxide Splitting...

    Office of Science (SC)

    and carbon dioxide splitting, two difficult yet key reactions for solar energy conversion. ... Image courtesy of UNC Chapel Hill (graphic art by Yan Liang) Electrochemical cell for ...

  17. Synchrotron X-ray Studies of Super-critical Carbon Dioxide /...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Synchrotron X-ray Studies of Super-critical Carbon Dioxide Reservoir Rock Interfaces Project obectives: Utilize synchrotron X-ray measurements, to monitor all aspects of atomic ...

  18. Effect of carbon dioxide and nitrogen on the diffusivity of methane...

    Office of Scientific and Technical Information (OSTI)

    Sponsoring Org: ORNL LDRD Director's R&D; SC USDOE - Office of Science (SC) Country of Publication: United States Language: English Subject: 03 NATURAL GAS; CARBON; CARBON DIOXIDE; ...

  19. Reduced-Order Model for the Geochemical Impacts of Carbon Dioxide...

    Office of Scientific and Technical Information (OSTI)

    Reduced-Order Model for the Geochemical Impacts of Carbon Dioxide, Brine and Trace Metal Leakage into an Unconfined, Oxidizing Carbonate Aquifer, Version 2.1 Citation Details...

  20. Table 4. 2011 State energy-related carbon dioxide emission shares...

    Energy Information Administration (EIA) (indexed site)

    2011 State energy-related carbon dioxide emission shares by sector " "percent of total" ,"shares" "State","Commercial","Electric Power","Residential","Industrial","Transportation"...

  1. Insulator-to-Metal Transition of Vanadium Dioxide | U.S. DOE...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    such as smart windows and ultrafast field effect transistors, exhibits an insulator to ... vanadium dioxide driven by large phonon entropy," Nature 515, 535-539, 2014. DOI: ...

  2. Sensitivity of helium beam-modulator design to uncertainties in biological data

    SciTech Connect

    Petti, P.L.; Lyman, J.T.; Castro, J.R. )

    1991-05-01

    The goal in designing beam-modulating devices for heavy charged-particle therapy is to achieve uniform biological effects across the spread-peak region of the beam. To accomplish this, the linear-quadratic model for cell survival has been used to describe the biological response of the target cells to charged-particle radiation. In this paper, the sensitivity of the beam-modulator design in the high-dose region to the values of the linear-quadratic variables {alpha} and {beta} has been investigated for a 215-MeV/u helium beam, and implications for higher LET beams are discussed. The major conclusions of this work are that, for helium over the LET range of 2 to 16 keV/{mu}, uncertainties in measuring {alpha} and {beta} for a given cell type which are of the order 20% or less have a negligible effect on the beam-modulator design (i.e., on the slope of the spread Bragg peak); uncertainties less than or equal to 10% in the dose-averaged LET at each depth are unimportant; and, if the linear-quadratic variables for the tumor differ from those used in the beam-modulator design by a constant factor between about 0.5 and 3, then the resultant nonuniformity in the photon-equivalent dose delivered to the tumor is within {plus minus}2.5%. It is also shown that for any ion, if the nominal values of {alpha} or {beta} used by the beam-modulator design program differ from their actual values by a constant factor, then the maximum errors possible in the beam-modulator design may be characterized by two limiting depth-dose curves such that the ratio of the dose at the proximal end of the spread Bragg curve to the dose at the distal end of the spread peak is given by {alpha}{sub distal}/{alpha}{sub prox} for the steepest curve, and ({beta}{sub distal}/{beta}{sub prox}){sup 1/2} for the flattest curve.

  3. The design, fabrication, operation and maintenance of (41) 400 H. P. -600 SCFM helium screw compressor systems (Five-year operation report)

    SciTech Connect

    Pallaver, C.

    1988-12-01

    Fermi National Accelerator Laboratory (Fermilab) uses thirty-four (34) identical compressor systems connected to a common header to supply clean high pressure helium gas feeding 26 refrigerators supplying liquid helium to 777 super conducting magnets. There are seven (7) similar compressor packages in other locations. The purpose of this paper is (after five years of operation) to present all the problems, modifications and experiences associated with the design and operation of these compressor systems.

  4. Project Profile: Direct Supercritical Carbon Dioxide Receiver Development

    Energy.gov [DOE]

    -- This project is inactive -- The National Renewable Energy Laboratory (NREL), under the National Laboratory R&D competitive funding opportunity, is working to develop, characterize, and experimentally demonstrate a novel high-temperature receiver technology using supercritical carbon dioxide (s-CO2) directly as the heat transfer fluid (HTF). A high-temperature receiver that is compatible with s-CO2 enables a significant increase in power cycle efficiency and reduces solar-field size, thereby decreasing the installed cost of concentrating solar power (CSP) systems.

  5. CATALYST EVALUATION FOR A SULFUR DIOXIDE-DEPOLARIZED ELECTROLYZER

    SciTech Connect

    Hobbs, D; Hector Colon-Mercado, H

    2007-01-31

    Thermochemical processes are being developed to provide global-scale quantities of hydrogen. A variant on sulfur-based thermochemical cycles is the Hybrid Sulfur (HyS) Process which uses a sulfur dioxide depolarized electrolyzer (SDE) to produce the hydrogen. Testing examined the activity and stability of platinum and palladium as the electrocatalyst for the SDE in sulfuric acid solutions. Cyclic and linear sweep voltammetry revealed that platinum provided better catalytic activity with much lower potentials and higher currents than palladium. Testing also showed that the catalyst activity is strongly influenced by the concentration of the sulfuric acid electrolyte.

  6. Catalyst for the reduction of sulfur dioxide to elemental sulfur

    DOEpatents

    Jin, Y.; Yu, Q.; Chang, S.G.

    1996-02-27

    The inventive catalysts allow for the reduction of sulfur dioxide to elemental sulfur in smokestack scrubber environments. The catalysts have a very high sulfur yield of over 90% and space velocity of 10,000 h{sup {minus}1}. They also have the capacity to convert waste gases generated during the initial conversion into elemental sulfur. The catalysts have inexpensive components, and are inexpensive to produce. The net impact of the invention is to make this technology practically available to industrial applications. 21 figs.

  7. Moisture absorption results for vertical calciner plutonium dioxide product

    SciTech Connect

    Compton, J.A., Westinghouse Hanford

    1996-07-03

    A sample of calcined plutonium dioxide was exposed to room air for one week. The sample was weighed daily to determine if the material absorbed moisture from the room air. A random variation of weight was observed after the first day; however, the sample returned to its original weight at the end of the week. The loss on ignition for the material increased from 0.439 to 0.544 weight percent during this time. This change is considered inconsequential as the material will normally be packaged for storage within hours of its production.

  8. EVOLUTION OF POST-IMPACT REMNANT HELIUM STARS IN TYPE Ia SUPERNOVA REMNANTS WITHIN THE SINGLE-DEGENERATE SCENARIO

    SciTech Connect

    Pan, Kuo-Chuan; Ricker, Paul M.; Taam, Ronald E. E-mail: pmricker@illinois.edu

    2013-08-10

    The progenitor systems of Type Ia supernovae (SNe Ia) are still under debate. Based on recent hydrodynamics simulations, non-degenerate companions in the single-degenerate scenario (SDS) should survive the supernova (SN) impact. One way to distinguish between the SDS and the double-degenerate scenario is to search for the post-impact remnant stars (PIRSs) in SN Ia remnants. Using a technique that combines multi-dimensional hydrodynamics simulations with one-dimensional stellar evolution simulations, we have examined the post-impact evolution of helium-rich binary companions in the SDS. It is found that these helium-rich PIRSs (He PIRSs) dramatically expand and evolve to a luminous phase (L {approx} 10{sup 4} L{sub Sun }) about 10 yr after an SN explosion. Subsequently, they contract and evolve to become hot blue-subdwarf-like (sdO-like) stars by releasing gravitational energy, persisting as sdO-like stars for several million years before evolving to the helium red-giant phase. We therefore predict that a luminous OB-like star should be detectable within {approx}30 yr after the SN explosion. Thereafter, it will shrink and become an sdO-like star in the central regions of SN Ia remnants within star-forming regions for SN Ia progenitors evolved via the helium-star channel in the SDS. These He PIRSs are predicted to be rapidly rotating (v{sub rot} {approx}> 50 km s{sup -1}) and to have high spatial velocities (v{sub linear} {approx}> 500 km s{sup -1}). Furthermore, if SN remnants have diffused away and are not recognizable at a later stage, He PIRSs could be an additional source of single sdO stars and/or hypervelocity stars.

  9. First principles assessment of helium trapping in Y{sub 2}TiO{sub 5} in nano-featured ferritic alloys

    SciTech Connect

    Jin, Yanan; Jiang, Yong E-mail: odette@engineering.ucsb.edu; Yang, Litong; Lan, Guoqiang; Robert Odette, G. E-mail: odette@engineering.ucsb.edu; Yamamoto, Takuya; Shang, Jiacheng; Dang, Ying

    2014-10-14

    Nano-scale Y{sub 2}Ti{sub 2}O{sub 7} and Y{sub 2}TiO{sub 5} oxides are the major features that provide high strength and irradiation tolerance in nano-structured ferritic alloys. Here, we employ density functional theory to study helium trapping in Y{sub 2}TiO{sub 5}. The results suggest that helium is more deeply trapped in Y{sub 2}TiO{sub 5} compared to Y{sub 2}Ti{sub 2}O{sub 7}. Helium occupies open channels in Y{sub 2}TiO{sub 5}, where it weakly chemically interacts with neighboring oxygen anions, and results in less volume expansion compared to Y{sub 2}Ti{sub 2}O{sub 7}, reducing strains in the iron matrix. The corresponding helium mobility in these channels is very high. While its ultimate fate is to form oxide/matrix interface bubbles, transient deep trapping of helium in oxides plays a major role in the ability of NFA to manage helium distribution.

  10. Oil, gas, and helium references index for the Navajo Indian Reservation, Arizona, New Mexico, and Utah. [223 references

    SciTech Connect

    Bliss, J.D.

    1982-02-01

    The references which are listed in this document represent the readily available literature about oil, gas, and helium resources on or adjacent to the Navajo Indian Reservation. They were selected during the developmental phase of the Navajo Resource Information System (NRIS). The system contains a set of computerized data bases addressing various resource categories. The system was developed by the US Geological Survey in coordination with the Minerals Department, Navajo Nation. Literature is the foundation of resource assessment and the absence of such a compilation for the Navajo Nation prompted the development of a reference data base entitled nref, which consists of over 1300 records. The following reference list of approximately 230 references was selected from those citations which contain oil, gas, or helium in a keyword list attached to each citation. References to general literature on oil, gas, or helium may also be present. The main attempt was to list most of the literature published in the 1960's and 1970's for areas in, or adjacent to, the Navajo Reservation. References published prior to this were included only if readily available or if they seemed to represent areas or topics not covered in later publications. 223 references.

  11. Metal hydride differential scanning calorimetry as an approach to compositional determination of mixtures of hydrogen isotopologues and helium

    SciTech Connect

    Robinson, David B.; Luo, Weifang; Cai, Trevor Y.; Stewart, Kenneth D.

    2015-09-26

    Gaseous mixtures of diatomic hydrogen isotopologues and helium are often encountered in the nuclear energy industry and in analytical chemistry. Compositions of stored mixtures can vary due to interactions with storage and handling materials. When tritium is present, it decays to form ions and helium-3, both of which can lead to further compositional variation. Monitoring of composition is typically achieved by mass spectrometry, a method that is bulky and energy-intensive. Mass spectrometers disperse sample material through vacuum pumps, which is especially troublesome if tritium is present. Moreover, our ultimate goal is to create a compact, fast, low-power sensor that can determine composition with minimal gas consumption and waste generation, as a complement to mass spectrometry that can be instantiated more widely. We propose calorimetry of metal hydrides as an approach to this, due to the strong isotope effect on gas absorption, and demonstrate the sensitivity of measured heat flow to atomic composition of the gas. Peak shifts are discernible when mole fractions change by at least 1%. A mass flow restriction results in a unique dependence of the measurement on helium concentration. We present a mathematical model as a first step toward prediction of the peak shapes and positions. The model includes a useful method to compute estimates of phase diagrams for palladium in the presence of arbitrary mixtures of hydrogen isotopologues. We expect that this approach can be used to deduce unknown atomic compositions from measured calorimetric data over a useful range of partial pressures of each component.

  12. MD simulations of phase stability of PuGa alloys: Effects of primary radiation defects and helium bubbles

    DOE PAGES [OSTI]

    Dremov, V. V.; Sapozhnikov, F. A.; Ionov, G. V.; Karavaev, A. V.; Vorobyova, M. A.; Chung, B. W.

    2013-05-14

    We present classical molecular dynamics (MD) with Modified Embedded Atom Model (MEAM) simulations to investigate the role of primary radiation defects and radiogenic helium as factors affecting the phase stability of PuGa alloys in cooling–heating cycles at ambient pressure. The models of PuGa alloys equilibrated at ambient conditions were subjected to cooling–heating cycles in which they were initially cooled down to 100 K and then heated up to 500 K at ambient pressure. The rate of temperature change in the cycles was 10 K/ns. The simulations showed that the initial FCC phase of PuGa alloys undergo polymorphous transition in coolingmore » to a lower symmetry α'-phase. All the alloys undergo direct and reverse polymorphous transitions in the cooling–heating cycles. The alloys containing vacancies shift in both transitions to lower temperatures relative to the defect-free alloys. The radiogenic helium has much less effect on the phase stability compared to that of primary radiation defects (in spite of the fact that helium concentration is twice of that for the primary radiation defects). Lastly, this computational result agrees with experimental data on unconventional stabilization mechanism of PuGa alloys.« less

  13. Rotational fluctuation of molecules in quantum clusters. II. Molecular rotation and superfluidity in OCS-doped helium-4 clusters

    SciTech Connect

    Miura, Shinichi [Institute for Molecular Science, 38 Myodaiji, Okazaki 444-8585 (Japan)

    2007-03-21

    In this paper, quantum fluctuations of a carbonyl sulfide molecule in helium-4 clusters are studied as a function of cluster size N in a small-to-large size regime (2{<=}N{<=}64). The molecular rotation of the dopant shows nonmonotonic size dependence in the range of 10{<=}N{<=}20, reflecting the density distribution of the helium atoms around the molecule. The size dependence on the rotational constant shows a plateau for N{>=}20, which is larger than the experimental nanodroplet value. Superfluid response of the doped cluster is found to show remarkable anisotropy especially for N{<=}20. The superfluid fraction regarding the axis perpendicular to the molecular axis shows a steep increase at N=10, giving the significant enhancement of the rotational fluctuation of the molecule. On the other hand, the superfluid fraction regarding the axis parallel to the molecular axis reaches 0.9 at N=5, arising from the bosonic exchange cycles of the helium atoms around the molecular axis. The anisotropy in the superfluid response is found to be the direct consequence of the configurations of the bosonic exchange cycles.

  14. Oxidation of PCEA nuclear graphite by low water concentrations in helium

    SciTech Connect

    Contescu, Cristian I; Mee, Robert; Wang, Peng; Romanova, Anna V; Burchell, Timothy D

    2014-10-01

    Accelerated oxidation tests were performed to determine kinetic parameters of the chronic oxidation reaction of PCEA graphite in contact with helium coolant containing low moisture concentrations in high temperature gas-cooled reactors. To the authors best knowledge such a study has not been done since the detailed analysis of reaction of H-451 graphite with steam [Velasquez, Hightower, Burnette, 1978]. Since that H-451 graphite is now unavailable, it is urgently needed to characterize chronic oxidation behavior of new graphite grades under qualification for gas-cooled reactors. The Langmuir-Hinshelwood mechanism of carbon oxidation by water results in a non-linear reaction rate expression, with at least six different parameters. They were determined in accelerated oxidation experiments that covered a large range of temperatures (800 to 1100 oC), and partial pressures of water (15 to 850 Pa) and hydrogen (30 to 150 Pa) and used graphite specimens thin enough (4 mm) in order to avoid diffusion effects. Data analysis employed a statistical method based on multiple likelihood estimation of parameters and simultaneous fitting of non-linear equations. The results show significant material-specific differences between graphite grades PCEA and H-451 which were attributed to microstructural dissimilarity of the two materials. It is concluded that kinetic data cannot be transferred from one graphite grade to another.

  15. Transient heat transfer in helium II due to a sudden vacuum break

    SciTech Connect

    Bosque, Ernesto S.; Dhuley, Ram C.; Van Sciver, Steven W.

    2014-01-29

    To ensure future cryogenic devices meet safety and operational specifications, significant value is gained from a developed understanding of the transient heat fluxes that result from failure of an insulating vacuum jacket around a helium II (He II)-cooled device. A novel, one-dimensional experiment is successfully performed examining the phenomena immediately following a vacuum rupture onto a cryosurface. In the experiment, a fast-opening (∼10 ms) valve isolates a rigid container of ultra high purity nitrogen (N{sub 2}) gas kept at room temperature and adjustable pressure from a vertically oriented, highly evacuated (∼10{sup −3} Pa) tube roughly 1 m in length. The bottom of the evacuated tube is sealed via a 2.54 mm thick copper disk, whose bottom surface is in intimate contact with an open column of He II (∼1.8 K). The evacuated tube, disk, and He II column share a diameter of 24 mm. Opening the valve results in a vacuum rupture. N{sub 2} gas is immediately drawn into the evacuated space and cryopumped onto the disk as a growing layer of solid cryodeposit. Various coupled transient heat transfer processes proceed as the internal energy of the warm gas is transferred through the growing layer of solid N{sub 2}, through the copper disk, and into the He II column. This work examines the qualitative nature of these transient phenomena and the magnitude of the heat fluxes present through each of the series of thermal resistances.

  16. Cryodeposition of nitrogen gas on a surface cooled by helium II

    SciTech Connect

    Dhuley, R. C.; Bosque, E. S.; Van Sciver, S. W.

    2014-01-29

    Catastrophic loss of beam tube vacuum in a superconducting particle accelerator can be simulated by sudden venting of a long high vacuum channel cooled on its outer surface by He II. The rapid rush of atmospheric air in such an event shows an interesting propagation effect, which is much slower than the shock wave that occurs with vacuum loss at ambient conditions. This is due to flash frosting/deposition of air on the cold walls of the channel. Hence to characterize the propagation as well as the associated heat transfer, it is first necessary to understand the deposition process. Here we attempt to model the growth of nitrogen frost layer on a cold plate in order to estimate its thickness with time. The deposition process can be divided into two regimes- free molecular and continuum. It is shown that in free molecular regime, the frost growth can be modeled reasonably well using cryopump theory and general heat transfer relations. The continuum regime is more complex to model, given the higher rate of gas incident on cryosurface causing a large heat load on helium bath and changing cryosurface temperature. Results from the continuum regime are discussed in the context of recent experiments performed in our laboratory.

  17. Commissioning of helium injector for coupled radio frequency quadrupole and separated function radio frequency quadrupole accelerator

    SciTech Connect

    Peng, Shixiang Chen, Jia; Ren, Haitao; Zhao, Jie; Xu, Yuan; Zhang, Tao; Xia, Wenlong; Gao, Shuli; Wang, Zhi; Luo, Yuting; Guo, Zhiyu; Zhang, Ailing; Chen, Jia'er; University of Chinese Academy of Sciences, Beijing 100049

    2014-02-15

    A project to study a new type of acceleration structure has been launched at Peking University, in which a traditional radio frequency quadrupole (RFQ) and a separated function radio frequency quadrupole are coupled in one cavity to accelerate the He+ beam. A helium injector for this project is developed. The injector consists of a 2.45 GHz permanent magnet electron cyclotron resonance ion source and a 1.16 m long low energy beam transport (LEBT). The commissioning of this injector was carried out and an onsite test was held in June 2013. A 14 mA He+ beam with the energy of 30 keV has been delivered to the end of the LEBT, where a diaphragm with the diameter of 7 mm is located. The position of the diaphragm corresponds to the entrance of the RFQ electrodes. The beam emittance and fraction were measured after the 7 mm diaphragm. Its rms emittance is about 0.14 ??mm?mrad and the fraction of He+ is about 99%.

  18. Two-dimensional simulation of spatiotemporal generation of dielectric barrier columnar discharges in atmospheric helium

    SciTech Connect

    Huang, Zhiming; Hao, Yanpeng; Yang, Lin; Han, Yongxia; Li, Licheng

    2015-12-15

    A two-dimensional (2D) fluid model is presented to investigate the spatiotemporal generation and dynamic mechanics of dielectric barrier columnar discharges in atmospheric helium. The model was examined with discharge currents measured in experiments and images taken by an intensified charge couple device camera. Based on the model, a columnar discharge was simulated for several cycles after being ignited. The discharge could be regarded as an initial unstable stage for the first three and a half cycles, then a steady state for the following cycles. In the initial stage, the discharge evolves from a uniform pattern into a columnar one. The calculated equipotential lines, 2D radial electric field, and electron density distributions at the edge of uniform discharges show the radial electric field accounts for the shrinking discharge area and the formation of discharge columns in the end. The columnar glow discharges and the Townsend discharges beyond the columns could coexist in the initial stage, and a Townsend discharge might develop into a new glow column in the next half-cycle. The radial electric field surrounding a glow discharge column has an inhibiting effect on the ionization in the peripheral area.

  19. Waste heat recovery from the European Spallation Source cryogenic helium plants - implications for system design

    SciTech Connect

    Jurns, John M.; Bäck, Harald; Gierow, Martin

    2014-01-29

    The European Spallation Source (ESS) neutron spallation project currently being designed will be built outside of Lund, Sweden. The ESS design includes three helium cryoplants, providing cryogenic cooling for the proton accelerator superconducting cavities, the target neutron source, and for the ESS instrument suite. In total, the cryoplants consume approximately 7 MW of electrical power, and will produce approximately 36 kW of refrigeration at temperatures ranging from 2-16 K. Most of the power consumed by the cryoplants ends up as waste heat, which must be rejected. One hallmark of the ESS design is the goal to recycle waste heat from ESS to the city of Lund district heating system. The design of the cooling system must optimize the delivery of waste heat from ESS to the district heating system and also assure the efficient operation of ESS systems. This report outlines the cooling scheme for the ESS cryoplants, and examines the effect of the cooling system design on cryoplant design, availability and operation.

  20. High-resolution thermal expansion measurements under helium-gas pressure

    SciTech Connect

    Manna, Rudra Sekhar; Wolf, Bernd; Souza, Mariano de; Lang, Michael

    2012-08-15

    We report on the realization of a capacitive dilatometer, designed for high-resolution measurements of length changes of a material for temperatures 1.4 K Less-Than-Or-Slanted-Equal-To T Less-Than-Or-Slanted-Equal-To 300 K and hydrostatic pressure P Less-Than-Or-Slanted-Equal-To 250 MPa. Helium ({sup 4}He) is used as a pressure-transmitting medium, ensuring hydrostatic-pressure conditions. Special emphasis has been given to guarantee, to a good approximation, constant-pressure conditions during temperature sweeps. The performance of the dilatometer is demonstrated by measurements of the coefficient of thermal expansion at pressures P Asymptotically-Equal-To 0.1 MPa (ambient pressure) and 104 MPa on a single crystal of azurite, Cu{sub 3}(CO{sub 3}){sub 2}(OH){sub 2}, a quasi-one-dimensional spin S = 1/2 Heisenberg antiferromagnet. The results indicate a strong effect of pressure on the magnetic interactions in this system.

  1. Surface studies and implanted helium measurements following NOVA high-yield DT experiments

    SciTech Connect

    Stoyer, M.A.; Hudson, G.B.

    1997-02-18

    This paper presents the results of three March 6, 1996 direct-drive high-yield DT NOVA experiments and provides `proof-of-principal` results for the quantitative measurement of energetic He ions. Semiconductor quality Si wafers and an amorphous carbon wafer were exposed to NOVA high-yield implosions. Surface damage was sub-micron in general, although the surface ablation was slightly greater for the carbon wafer than for the Si wafers. Melting of a thin ({approx} 0.1{mu}) layer of Si was evident from microscopic investigation. Electron microscopy indicated melted blobs of many different metals (e.g. Al, Au, Ta, Fe alloys, Cu and even Cd) on the surfaces. The yield measured by determining the numbers of atoms of implanted {sup 4}He and {sup 3}He indicate the number of DT fusions to be 9.1({plus_minus}2.3) X 10{sup 12} and DD fusions to be 4.8({plus_minus}1.0) x 10{sup 10}, respectively. The helium DT fusion yield is slightly lower than that of the Cu activation measurement, which was 1.3({plus_minus}0.l) x 10{sup 13} DT fusions.

  2. Photoionization study of doubly-excited helium at ultra-high resolution

    SciTech Connect

    Kaindl, G.; Schulz, K.; Domke, M.

    1997-04-01

    Ever since the pioneering work of Madden & Codling and Cooper, Fano & Prats on doubly-excited helium in the early sixties, this system may be considered as prototypical for the study of electron-electron correlations. More detailed insight into these states could be reached only much later, when improved theoretical calculations of the optically-excited {sup 1}P{sup 0} double-excitation states became available and sufficiently high energy resolution ({delta}E=4.0 meV) was achieved. This allowed a systematic investigation of the double-excitation resonances of He up to excitation energies close to the double-ionization threshold, I{sub infinity}=79.003 eV, which stimulated renewed theoretical interest into these correlated electron states. The authors report here on striking progress in energy resolution in this grazing-incidence photon-energy range of grating monochromators and its application to hitherto unobservable states of doubly-excited He. By monitoring an extremely narrow double-excitation resonance of He, with a theoretical lifetime width of less than or equal to 5 {mu}eV, a resolution of {delta}E=1.0 meV (FWHM) at 64.1 eV could be achieved. This ultra-high spectral resolution, combined with high photon flux, allowed the investigation of new Rydberg resonances below the N=3 ionization threshold, I{sub 3}, as well as a detailed comparison with ab-initio calculations.

  3. Engineering the Big Chill: The story of JLab’s Central Helium Liquefier

    DOE PAGES [OSTI]

    Westfall, Catherine

    2014-03-29

    This article tells the story of the Central Helium Liquefier (CHL) at the Thomas Jefferson National Accelerator Facility (JLab), one of the US National Laboratories. JLab’s successful superconducting radio frequency accelerator was only possible because a group of JLab engineers successfully tackled a complex of difficulties to build a cryogenic system that included the CHL, a task that required advancing the frontier of cryogenic technology. Ultimately, these cryogenic advances were applied far beyond JLab to the benefit of cutting-edge programs at other US national laboratories (Oak Ridge, Brookhaven, and the Facility for Rare Isotope Beams at MSU) as well asmore » NASA. In addition, this innovation story dramatizes the sort of engineer-driven technological problem solving that allows the successful launch and operation of experimental projects. Along the way, the CHL story also provides an important addition to our understanding of the role played by engineers and industry in creating knowledge at physics laboratories.« less

  4. Performance evaluation approach for the supercritical helium cold circulators of ITER

    SciTech Connect

    Vaghela, H.; Sarkar, B.; Bhattacharya, R.; Kapoor, H.; Chalifour, M.; Chang, H.-S.; Serio, L.

    2014-01-29

    The ITER project design foresees Supercritical Helium (SHe) forced flow cooling for the main cryogenic components, namely, the superconducting (SC) magnets and cryopumps (CP). Therefore, cold circulators have been selected to provide the required SHe mass flow rate to cope with specific operating conditions and technical requirements. Considering the availability impacts of such machines, it has been decided to perform evaluation tests of the cold circulators at operating conditions prior to the series production in order to minimize the project technical risks. A proposal has been conceptualized, evaluated and simulated to perform representative tests of the full scale SHe cold circulators. The objectives of the performance tests include the validation of normal operating condition, transient and off-design operating modes as well as the efficiency measurement. A suitable process and instrumentation diagram of the test valve box (TVB) has been developed to implement the tests at the required thermodynamic conditions. The conceptual engineering design of the TVB has been developed along with the required thermal analysis for the normal operating conditions to support the performance evaluation of the SHe cold circulator.

  5. Radial behavior of the pulsed dielectric-barrier discharge in atmospheric helium

    SciTech Connect

    Zhang Dingzong; Wang Yanhui; Wang Dezhen

    2012-12-15

    The radial behavior of the pulsed dielectric-barrier discharge in atmospheric helium is studied by a two-dimensional, self-consistent fluid model. It is found that the two discharges ignited during one voltage pulse can possess different radial behaviors, and the discharge behavior is determined by the electron density distribution right before this discharge is ignited. The electron density distributions before the two discharges start depend on the time intervals between two discharges and their previous discharge processes. If the electron density distribution is radially uniform at the end of the previous discharge, the shorter the time interval between two discharges is, the more uniform the electron density distribution before the next discharge is, and thus the more homogenous the subsequent discharge becomes. In pulsed discharge, the time intervals between two discharges are mainly determined by the duration and repetition frequency of applied voltage pulse. These results are further supported by the investigation of the discharge behaviors under different pulse durations and repetition frequencies.

  6. Interfacial tension in high-pressure carbon dioxide mixtures

    SciTech Connect

    Chun, B.S.; Wilkinson, G.T.

    1995-12-01

    High-pressure interfacial- and surface-tension phenomena govern the migration and recovery of oil and gas from hydrocarbon reservoirs. The phenomena are of particular relevance to phase separation and mass transfer in light hydrocarbon fractionation plants and in propane deasphalting in lubricating oil refining. Interfacial tensions of carbon dioxide-water-alcohol mixtures were measured at temperatures in the range 5--71 C and pressures 0.1--18.6 MPa, using the capillary rise method. The alcohols were methanol (0.136 mf), ethanol (to 0.523 mf), and isopropyl alcohol (to 0.226 mf). Interfacial tension (IFT) decreased linearly with both temperature and pressure din the low-pressure range (gaseous CO{sub 2}) but was largely independent of pressure at high pressure (liquid or supercritical CO{sub 2}). There was a zone in the vicinity of the critical pressure of CO{sub 2}-as much as 20 C below and 10 C above the carbon dioxide critical temperature--where IFT became small. This is attributed to the formation of a second CO{sub 2}-rich phase. The isotherms exhibited a crossover pressure near 3 MPa for all systems examined.

  7. Calculating the probability of injected carbon dioxide plumes encountering faults

    SciTech Connect

    Jordan, P.D.

    2011-04-01

    One of the main concerns of storage in saline aquifers is leakage via faults. In the early stages of site selection, site-specific fault coverages are often not available for these aquifers. This necessitates a method using available fault data to estimate the probability of injected carbon dioxide encountering and migrating up a fault. The probability of encounter can be calculated from areal fault density statistics from available data, and carbon dioxide plume dimensions from numerical simulation. Given a number of assumptions, the dimension of the plume perpendicular to a fault times the areal density of faults with offsets greater than some threshold of interest provides probability of the plume encountering such a fault. Application of this result to a previously planned large-scale pilot injection in the southern portion of the San Joaquin Basin yielded a 3% and 7% chance of the plume encountering a fully and half seal offsetting fault, respectively. Subsequently available data indicated a half seal-offsetting fault at a distance from the injection well that implied a 20% probability of encounter for a plume sufficiently large to reach it.

  8. Carbon Dioxide Information Analysis Center: FY 1991 activities

    SciTech Connect

    Cushman, R.M.; Stoss, F.W.

    1992-06-01

    During the course of a fiscal year, Oak Ridge National Laboratory's Carbon Dioxide Information Analysis Center (CDIAC) distributes thousands of specially publications-numeric data packages (NDPs), computer model packages (CMPs), technical reports, public communication publications, newsletters, article reprints, and reference books-in response to requests for information related to global environmental issues, primarily those pertaining to climate change. CDIAC's staff also provides technical responses to specific inquiries related to carbon dioxide (CO{sub 2}), other trace gases, and climate. Hundreds of referrals to other researchers, policy analysts, information specialists, or organizations are also facilitated by CDIAC's staff. This report provides an account of the activities accomplished by CDIAC during the period October 1, 1990 to September 30, 1991. An organizational overview of CDIAC and its staff is supplemented by a detailed description of inquiries received and CDIAC's response to those inquiries. An analysis and description of the preparation and distribution of numeric data packages, computer model packages, technical reports, newsletters, factsheets, specially publications, and reprints is provided. Comments and descriptions of CDIAC's information management systems, professional networking, and special bilateral agreements are also described.

  9. Carbon Dioxide Information Analysis Center: FY 1991 activities

    SciTech Connect

    Cushman, R.M.; Stoss, F.W.

    1992-06-01

    During the course of a fiscal year, Oak Ridge National Laboratory`s Carbon Dioxide Information Analysis Center (CDIAC) distributes thousands of specially publications-numeric data packages (NDPs), computer model packages (CMPs), technical reports, public communication publications, newsletters, article reprints, and reference books-in response to requests for information related to global environmental issues, primarily those pertaining to climate change. CDIAC`s staff also provides technical responses to specific inquiries related to carbon dioxide (CO{sub 2}), other trace gases, and climate. Hundreds of referrals to other researchers, policy analysts, information specialists, or organizations are also facilitated by CDIAC`s staff. This report provides an account of the activities accomplished by CDIAC during the period October 1, 1990 to September 30, 1991. An organizational overview of CDIAC and its staff is supplemented by a detailed description of inquiries received and CDIAC`s response to those inquiries. An analysis and description of the preparation and distribution of numeric data packages, computer model packages, technical reports, newsletters, factsheets, specially publications, and reprints is provided. Comments and descriptions of CDIAC`s information management systems, professional networking, and special bilateral agreements are also described.

  10. Carbon Dioxide Information Analysis Center: FY 1992 activities

    SciTech Connect

    Cushman, R.M.; Stoss, F.W.

    1993-03-01

    During the course of a fiscal year, Oak Ridge National Laboratory`s Carbon Dioxide Information Analysis Center (CDIAC) distributes thousands of specialty publications-numeric data packages (NDPs), computer model packages (CMPs), technical reports, public communication publications, newsletters, article reprints, and reference books-in response to requests for information related to global environmental issues, primarily those pertaining to climate change. CDIACs staff also provides technical responses to specific inquiries related to carbon dioxide (CO{sub 2}), other trace gases, and climate. Hundreds of referrals to other researchers, policy analysts, information specialists, or organizations are also facilitated by CDIAC`s staff. This report provides an account of the activities accomplished by CDIAC during the period October 1, 1991 to September 30, 1992. An organizational overview of CDIAC and its staff is supplemented by a detailed description of inquiries received and CDIAC`s response to those inquiries. As analysis and description of the preparation and distribution of numeric data packages, computer model packages, technical reports, newsletters, fact sheets, specialty publications, and reprints is provided. Comments and descriptions of CDIAC`s information management systems, professional networking, and special bilateral agreements are also described.

  11. Combustion systems and power plants incorporating parallel carbon dioxide capture and sweep-based membrane separation units to remove carbon dioxide from combustion gases

    DOEpatents

    Wijmans, Johannes G.; Merkel, Timothy C; Baker, Richard W.

    2011-10-11

    Disclosed herein are combustion systems and power plants that incorporate sweep-based membrane separation units to remove carbon dioxide from combustion gases. In its most basic embodiment, the invention is a combustion system that includes three discrete units: a combustion unit, a carbon dioxide capture unit, and a sweep-based membrane separation unit. In a preferred embodiment, the invention is a power plant including a combustion unit, a power generation system, a carbon dioxide capture unit, and a sweep-based membrane separation unit. In both of these embodiments, the carbon dioxide capture unit and the sweep-based membrane separation unit are configured to be operated in parallel, by which we mean that each unit is adapted to receive exhaust gases from the combustion unit without such gases first passing through the other unit.

  12. Thermal and Physical Properties of Plutonium Dioxide Produced from the Oxidation of Metal: a Data Summary

    SciTech Connect

    Wayne, David M.

    2014-01-13

    The ARIES Program at the Los Alamos National Laboratory removes plutonium metal from decommissioned nuclear weapons, and converts it to plutonium dioxide in a specially-designed Direct Metal Oxidation furnace. The plutonium dioxide is analyzed for specific surface area, particle size distribution, and moisture content. The purpose of these analyses is to certify that the plutonium dioxide powder meets or exceeds the specifications of the end-user, and the specifications for the packaging and transport of nuclear materials. Analytical results from plutonium dioxide from ARIES development activities, from ARIES production activities, from muffle furnace oxidation of metal, and from metal that was oxidized over a lengthy time interval in air at room temperature, are presented. The processes studied produce plutonium dioxide powder with distinct differences in measured properties, indicating the significant influence of oxidation conditions on physical properties.

  13. Sulfur dioxide capture in the combustion of mixtures of lime, refuse-derived fuel, and coal

    SciTech Connect

    Churney, K.L.; Buckley, T.J. . Center for Chemical Technology)

    1990-06-01

    Chlorine and sulfur mass balance studies have been carried out in the combustion of mixtures of lime, refuse-derived fuel, and coal in the NIST multikilogram capacity batch combustor. The catalytic effect of manganese dioxide on the trapping of sulfur dioxide by lime was examined. Under our conditions, only 4% of the chlorine was trapped in the ash and no effect of manganese dioxide was observed. Between 42 and 14% of the total sulfur was trapped in the ash, depending upon the lime concentration. The effect of manganese dioxide on sulfur capture was not detectable. The temperature of the ash was estimated to be near 1200{degrees}C, which was in agreement with that calculated from sulfur dioxide capture thermodynamics. 10 refs., 12 figs., 10 tabs.

  14. Chapter 4: Advancing Clean Electric Power Technologies | Carbon Dioxide Capture for Natural Gas and Industrial Applications Technology Assessment

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Gas and Industrial Applications Carbon Dioxide Capture Technologies Carbon Dioxide Storage Technologies Crosscutting Technologies in Carbon Dioxide Capture and Storage Fast-spectrum Reactors Geothermal Power High Temperature Reactors Hybrid Nuclear-Renewable Energy Systems Hydropower Light Water Reactors Marine and Hydrokinetic Power Nuclear Fuel Cycles Solar Power Stationary Fuel Cells Supercritical Carbon Dioxide Brayton Cycle Wind Power ENERGY U.S. DEPARTMENT OF Clean Power Quadrennial

  15. Chapter 4: Advancing Clean Electric Power Technologies | Crosscutting Technologies in Carbon Dioxide Capture and Storage Technology Assessment

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Gas and Industrial Applications Carbon Dioxide Capture Technologies Carbon Dioxide Storage Technologies Crosscutting Technologies in Carbon Dioxide Capture and Storage Fast-spectrum Reactors Geothermal Power High Temperature Reactors Hybrid Nuclear-Renewable Energy Systems Hydropower Light Water Reactors Marine and Hydrokinetic Power Nuclear Fuel Cycles Solar Power Stationary Fuel Cells Supercritical Carbon Dioxide Brayton Cycle Wind Power ENERGY U.S. DEPARTMENT OF Clean Power Quadrennial

  16. Fluid Dynamics of Carbon Dioxide Disposal into Saline Aquifers

    SciTech Connect

    Garcia, Julio Enrique

    2003-12-18

    Injection of carbon dioxide (CO{sub 2}) into saline aquifers has been proposed as a means to reduce greenhouse gas emissions (geological carbon sequestration). Large-scale injection of CO{sub 2} will induce a variety of coupled physical and chemical processes, including multiphase fluid flow, fluid pressurization and changes in effective stress, solute transport, and chemical reactions between fluids and formation minerals. This work addresses some of these issues with special emphasis given to the physics of fluid flow in brine formations. An investigation of the thermophysical properties of pure carbon dioxide, water and aqueous solutions of CO{sub 2} and NaCl has been conducted. As a result, accurate representations and models for predicting the overall thermophysical behavior of the system CO{sub 2}-H{sub 2}O-NaCl are proposed and incorporated into the numerical simulator TOUGH2/ECO{sub 2}. The basic problem of CO{sub 2} injection into a radially symmetric brine aquifer is used to validate the results of TOUGH2/ECO2. The numerical simulator has been applied to more complex flow problem including the CO{sub 2} injection project at the Sleipner Vest Field in the Norwegian sector of the North Sea and the evaluation of fluid flow dynamics effects of CO{sub 2} injection into aquifers. Numerical simulation results show that the transport at Sleipner is dominated by buoyancy effects and that shale layers control vertical migration of CO{sub 2}. These results are in good qualitative agreement with time lapse surveys performed at the site. High-resolution numerical simulation experiments have been conducted to study the onset of instabilities (viscous fingering) during injection of CO{sub 2} into saline aquifers. The injection process can be classified as immiscible displacement of an aqueous phase by a less dense and less viscous gas phase. Under disposal conditions (supercritical CO{sub 2}) the viscosity of carbon dioxide can be less than the viscosity of the aqueous

  17. Synthesis, characterization, and thermodynamic parameters of vanadium dioxide

    SciTech Connect

    Qi Ji [Department of Chemical Engineering of Material, School of Chemical Engineering, Dalian University of Technology, 158 Zhongshan Road, Dalian 116012 (China); Department of Chemical Engineering, Dalian Life Science College, Dalian Nationalities University, 18 Laohe West Road, Dalian 116600 (China); Ning Guiling [Department of Chemical Engineering of Material, School of Chemical Engineering, Dalian University of Technology, 158 Zhongshan Road, Dalian 116012 (China)], E-mail: ninggl@dlut.edu.cn; Lin Yuan [Department of Chemical Engineering of Material, School of Chemical Engineering, Dalian University of Technology, 158 Zhongshan Road, Dalian 116012 (China)

    2008-08-04

    A novel process was developed for synthesizing pure thermochromic vanadium dioxide (VO{sub 2}) by thermal reduction of vanadium pentoxide (V{sub 2}O{sub 5}) in ammonia gas. The process of thermal reduction of V{sub 2}O{sub 5} was optimized by both experiments and modeling of thermodynamic parameters. The product VO{sub 2} was characterized by means of X-ray diffraction (XRD), X-ray photoelectron spectrometry (XPS), scanning electron microscopy (SEM), thermogravimetric analysis (TG), and differential scanning calorimetry (DSC). The experimental results indicated that pure thermochromic VO{sub 2} crystal particles were successfully synthesized. The phase transition temperature of the VO{sub 2} is approximately 342.6 K and the enthalpy of phase transition is 44.90 J/g.

  18. Management Opportunities for Enhancing Terrestrial Carbon Dioxide Sinks

    SciTech Connect

    Post, W. M.; Izaurralde, Roberto C.; West, Tristram O.; Liebig, Mark A.; King, Anthony W.

    2012-12-01

    The potential for mitigating increasing atmospheric carbon dioxide concentrations through the use of terrestrial biological carbon (C) sequestration is substantial. Here, we estimate the amount of C being sequestered by natural processes at global, North American, and national US scales. We present and quantify, where possible, the potential for deliberate human actions through forestry, agriculture, and use of biomass-based fuels to augment these natural sinks. Carbon sequestration may potentially be achieved through some of these activities but at the expense of substantial changes in land-use management. Some practices (eg reduced tillage, improved silviculture, woody bioenergy crops) are already being implemented because of their economic benefits and associated ecosystem services. Given their cumulative greenhouse-gas impacts, other strategies (eg the use of biochar and cellulosic bioenergy crops) require further evaluation to determine whether widespread implementation is warranted.

  19. Fabric compatibility and cleaning effectiveness of drycleaning with carbon dioxide

    SciTech Connect

    Williams, S.B.; Laintz, K.E.; Spall, W.D.; bustos, L.; Taylor, C.

    1996-04-01

    Liquid carbon dioxide (CO{sub 2}) offers an environmentally sound replacement solvent to the currently used drycleaning solvent, perchloroethylene (PERC). In addition to the health and safety benefits of a CO{sub 2} based cleaning system, large savings in solvent costs provide an incentive for conversion to the new system. Lower operating costs for the new technology provide further incentive. Experimental studies were conducted using CO{sub 2} in both small scale and pilot scale test systems in order to address fabric compatibility with this alternative cleaning method. Results from these tests show that fabric shrinkage using CO{sub 2} is controlled to the same level as current drycleaning methods. In addition, tests to evaluate the cleaning performance of liquid CO{sub 2} drycleaning were also conducted. These results show the prototype liquid CO{sub 2} cleaning system to be better than PERC at soil removal, and worse than PERC at inorganic salt removal.

  20. Aberration-corrected X-ray spectrum imaging and Fresnel contrast to differentiate nanoclusters and cavities in helium-irradiated alloy 14YWT

    SciTech Connect

    Miller, Michael K; Parish, Chad M

    2014-01-01

    Helium accumulation negatively impacts structural materials used in neutron-irradiated environments, such as fission and fusion reactors. Next-generation fission and fusion reactors will require structural materials, such as steels, resistant to large neutron doses yet see service temperatures in the range most affected by helium embrittlement. Previous work has indicated the difficulty of experimentally differentiating nanometer-sized helium bubbles from the Ti-Y-O rich nanoclustsers (NCs) in radiation-tolerant nanostructured ferritic alloys (NFAs). Because the NCs are expected to sequester helium away from grain boundaries and reduce embrittlement, experimental methods to study simultaneously the NC and bubble populations are needed. In this study, aberration-corrected scanning transmission electron microscopy (STEM) results combining high-collection-efficiency X-ray spectrum images (SIs), multivariate statistical analysis (MVSA), and Fresnel-contrast bright-field STEM imaging have been used for such a purpose. Results indicate that Fresnel-contrast imaging, with careful attention to TEM-STEM reciprocity, differentiates bubbles from NCs, and MVSA of X-ray SIs unambiguously identifies NCs. Therefore, combined Fresnel-contrast STEM and X-ray SI is an effective STEM-based method to characterize helium-bearing NFAs.

  1. Association of indoor nitrogen dioxide with respiratory symptoms and pulmonary function in children

    SciTech Connect

    Neas, L.M.; Dockery, D.W.; Ware, J.H.; Spengler, J.D.; Speizer, F.E.; Ferris, B.G. Jr. )

    1991-07-15

    The effect of indoor nitrogen dioxide on the cumulative incidence of respiratory symptoms and pulmonary function level was studied in a cohort of 1,567 white children aged 7-11 years examined in six US cities from 1983 through 1988. Week-long measurements of nitrogen dioxide were obtained at three indoor locations over 2 consecutive weeks in both the winter and the summer months. The household annual average nitrogen dioxide concentration was modeled as a continuous variable and as four ordered categories. Multiple logistic regression analysis of symptom reports from a questionnaire administered after indoor monitoring showed that a 15-ppb increase in the household annual nitrogen dioxide mean was associated with an increased cumulative incidence of lower respiratory symptoms (odds ratio (OR) = 1.4, 95% confidence interval (95% Cl) 1.1-1.7). The response variable indicated the report of one or more of the following symptoms: attacks of shortness of breath with wheeze, chronic wheeze, chronic cough, chronic phlegm, or bronchitis. Girls showed a stronger association (OR = 1.7, 95% Cl 1.3-2.2) than did boys (OR = 1.2, 95% Cl 0.9-1.5). An analysis of pulmonary function measurements showed no consistent effect of nitrogen dioxide. These results are consistent with earlier reports based on categorical indicators of household nitrogen dioxide sources and provide a more specific association with nitrogen dioxide as measured in children's homes.

  2. Statistically designed study of the variables and parameters of carbon dioxide equations of state

    SciTech Connect

    Donohue, M.D.; Naiman, D.Q.; Jin, Gang; Loehe, J.R.

    1991-05-01

    Carbon dioxide is used widely in enhanced oil recovery (EOR) processes to maximize the production of crude oil from aging and nearly depleted oil wells. Carbon dioxide also is encountered in many processes related to oil recovery. Accurate representations of the properties of carbon dioxide, and its mixtures with hydrocarbons, play a critical role in a number of enhanced oil recovery operations. One of the first tasks of this project was to select an equation of state to calculate the properties of carbon dioxide and its mixtures. The equations simplicity, accuracy, and reliability in representing phase behavior and thermodynamic properties of mixtures containing carbon dioxide with hydrocarbons at conditions relevant to enhanced oil recovery were taken into account. We also have determined the thermodynamic properties that are important to enhanced oil recovery and the ranges of temperature, pressure and composition that are important. We chose twelve equations of state for preliminary studies to be evaluated against these criteria. All of these equations were tested for pure carbon dioxide and eleven were tested for pure alkanes and their mixtures with carbon dioxide. Two equations, the ALS equation and the ESD equation, were selected for detailed statistical analysis. 54 refs., 41 figs., 36 tabs.

  3. Metal hydride differential scanning calorimetry as an approach to compositional determination of mixtures of hydrogen isotopologues and helium

    SciTech Connect

    Robinson, David B.; Luo, Weifang; Cai, Trevor Y.; Stewart, Kenneth D.

    2015-09-26

    Gaseous mixtures of diatomic hydrogen isotopologues and helium are often encountered in the nuclear energy industry and in analytical chemistry. Compositions of stored mixtures can vary due to interactions with storage and handling materials. When tritium is present, it decays to form ions and helium-3, both of which can lead to further compositional variation. Monitoring of composition is typically achieved by mass spectrometry, a method that is bulky and energy-intensive. Mass spectrometers disperse sample material through vacuum pumps, which is especially troublesome if tritium is present. Moreover, our ultimate goal is to create a compact, fast, low-power sensor that can determine composition with minimal gas consumption and waste generation, as a complement to mass spectrometry that can be instantiated more widely. We propose calorimetry of metal hydrides as an approach to this, due to the strong isotope effect on gas absorption, and demonstrate the sensitivity of measured heat flow to atomic composition of the gas. Peak shifts are discernible when mole fractions change by at least 1%. A mass flow restriction results in a unique dependence of the measurement on helium concentration. We present a mathematical model as a first step toward prediction of the peak shapes and positions. The model includes a useful method to compute estimates of phase diagrams for palladium in the presence of arbitrary mixtures of hydrogen isotopologues. As a result, we expect that this approach can be used to deduce unknown atomic compositions from measured calorimetric data over a useful range of partial pressures of each component.

  4. Metal hydride differential scanning calorimetry as an approach to compositional determination of mixtures of hydrogen isotopologues and helium

    DOE PAGES [OSTI]

    Robinson, David B.; Luo, Weifang; Cai, Trevor Y.; Stewart, Kenneth D.

    2015-09-26

    Gaseous mixtures of diatomic hydrogen isotopologues and helium are often encountered in the nuclear energy industry and in analytical chemistry. Compositions of stored mixtures can vary due to interactions with storage and handling materials. When tritium is present, it decays to form ions and helium-3, both of which can lead to further compositional variation. Monitoring of composition is typically achieved by mass spectrometry, a method that is bulky and energy-intensive. Mass spectrometers disperse sample material through vacuum pumps, which is especially troublesome if tritium is present. Moreover, our ultimate goal is to create a compact, fast, low-power sensor that canmore » determine composition with minimal gas consumption and waste generation, as a complement to mass spectrometry that can be instantiated more widely. We propose calorimetry of metal hydrides as an approach to this, due to the strong isotope effect on gas absorption, and demonstrate the sensitivity of measured heat flow to atomic composition of the gas. Peak shifts are discernible when mole fractions change by at least 1%. A mass flow restriction results in a unique dependence of the measurement on helium concentration. We present a mathematical model as a first step toward prediction of the peak shapes and positions. The model includes a useful method to compute estimates of phase diagrams for palladium in the presence of arbitrary mixtures of hydrogen isotopologues. As a result, we expect that this approach can be used to deduce unknown atomic compositions from measured calorimetric data over a useful range of partial pressures of each component.« less

  5. New Benchmarks from Tokamak Experiments for Theoretical Calculations of the Dielectronic Satellite Spectra of Helium-like Ions

    SciTech Connect

    M. Bitter; M.F. Gu; L.A. Vainshtein; P. Beiersdorfer; G. Bertschinger; O. Marchuk; R. Bell; B. LeBlanc; K.W. Hill; D. Johnson; L. Roquemore

    2003-08-29

    Dielectronic satellite spectra of helium-like argon, recorded with a high-resolution X-ray crystal spectrometer at the National Spherical Torus Experiment, were found to be inconsistent with existing predictions resulting in unacceptable values for the power balance and suggesting the unlikely existence of non-Maxwellian electron energy distributions. These problems were resolved with calculations from a new atomic code. It is now possible to perform reliable electron temperature measurements and to eliminate the uncertainties associated with determinations of non-Maxwellian distributions.

  6. Tunneling effects in the kinetics of helium and hydrogen isotopes desorption from single-walled carbon nanotube bundles

    SciTech Connect

    Danilchenko, B. A. Yaskovets, I. I.; Uvarova, I. Y.; Dolbin, A. V.; Esel'son, V. B.; Basnukaeva, R. M.; Vinnikov, N. A.

    2014-04-28

    The kinetics of desorption both helium isotopes and molecules of hydrogen and deuterium from open-ended or ?-irradiated single-walled carbon nanotube bundles was investigated in temperature range of 10300?K. The gases desorption rates obey the Arrhenius law at high temperatures, deviate from it with temperature reduction and become constant at low temperatures. These results indicate the quantum nature of gas outflow from carbon nanotube bundles. We had deduced the crossover temperature below which the quantum corrections to the effective activation energy of desorption become significant. This temperature follows linear dependence against the inverse mass of gas molecule and is consistent with theoretical prediction.

  7. The separation of lanthanides and actinides in supercritical fluid carbon dioxide

    DOE PAGES [OSTI]

    Mincher, Bruce J.; Wai, Chien M.; Fox, Robert V.; Baek, Donna L.; Yen, Clive; Case, Mary E.

    2015-10-28

    Supercritical fluid carbon dioxide presents an attractive alternative to conventional solvents for recovery of the actinides and lanthanides. Carbon dioxide is a good solvent for fluorine and phosphate-containing ligands, including the traditional tributylphosphate ligand used in process-scale uranium separations. Actinide and lanthanide oxides may even be directly dissolved in carbon dioxide containing the complexes formed between these ligands and mineral acids, obviating the need for large volumes of acids for leaching and dissolution, and the corresponding organic liquid–liquid solvent extraction solutions. As a result, examples of the application of this novel technology for actinide and lanthanide separations are presented.

  8. A New Leaf: Scientists Turn Carbon Dioxide Back Into Fuel | Department of

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Energy A New Leaf: Scientists Turn Carbon Dioxide Back Into Fuel A New Leaf: Scientists Turn Carbon Dioxide Back Into Fuel August 18, 2016 - 3:41pm Addthis Plants capture CO2 and convert it into sugars that store energy. | Public Domain photo. Plants capture CO2 and convert it into sugars that store energy. | Public Domain photo. Jared Sagoff Argonne National Laboratory Can we turn carbon dioxide into fuel, rather than a pollutant? A group of researchers asked that question and found a way

  9. Method of determining pH by the alkaline absorption of carbon dioxide

    DOEpatents

    Hobbs, D.T.

    1992-10-06

    A method is described for measuring the concentration of hydroxides in alkaline solutions in a remote location using the tendency of hydroxides to absorb carbon dioxide. The method includes the passing of carbon dioxide over the surface of an alkaline solution in a remote tank before and after measurements of the carbon dioxide solution. A comparison of the measurements yields the absorption fraction from which the hydroxide concentration can be calculated using a correlation of hydroxide or pH to absorption fraction. 2 figs.

  10. Concept Design for a High Temperature Helium Brayton Cycle with Interstage Heating and Cooling

    SciTech Connect

    Wright, Steven A.; Vernon, Milton E.; Pickard, Paul S.

    2013-12-01

    The primary metric for the viability of these next generation nuclear power plants will be the cost of generated electricity. One important component in achieving these objectives is the development of power conversion technologies that maximize the electrical power output of these advanced reactors for a given thermal power. More efficient power conversion systems can directly reduce the cost of nuclear generated electricity and therefore advanced power conversion cycle research is an important area of investigation for the Generation IV Program. Brayton cycles using inert or other gas working fluids, have the potential to take advantage of the higher outlet temperature range of Generation IV systems and allow substantial increases in nuclear power conversion efficiency, and potentially reductions in power conversion system capital costs compared to the steam Rankine cycle used in current light water reactors. For the Very High Temperature Reactor (VHTR), Helium Brayton cycles which can operate in the 900 to 950 C range have been the focus of power conversion research. Previous Generation IV studies examined several options for He Brayton cycles that could increase efficiency with acceptable capital cost implications. At these high outlet temperatures, Interstage Heating and Cooling (IHC) was shown to provide significant efficiency improvement (a few to 12%) but required increased system complexity and therefore had potential for increased costs. These scoping studies identified the potential for increased efficiency, but a more detailed analysis of the turbomachinery and heat exchanger sizes and costs was needed to determine whether this approach could be cost effective. The purpose of this study is to examine the turbomachinery and heat exchanger implications of interstage heating and cooling configurations. In general, this analysis illustrates that these engineering considerations introduce new constraints to the design of IHC systems that may require

  11. Carbon Dioxide Separation with Novel Microporous Metal Organic Frameworks

    SciTech Connect

    Richard Willis; Annabelle Benin; John Low; Ganesh Venimadhavan; Syed Faheem; David Lesch; Adam Matzger; Randy Snurr

    2008-02-04

    The goal of this program was to develop a low cost novel sorbent to remove carbon dioxide from flue gas and gasification streams in electric utilities. Porous materials named metal-organic frameworks (MOFs) were found to have good capacity and selectivity for the capture of carbon dioxide. Several materials from the initial set of reference MOFs showed extremely high CO{sub 2} adsorption capacities and very desirable linear isotherm shapes. Sample preparation occurred at a high level, with a new family of materials suitable for intellectual property protection prepared and characterized. Raman spectroscopy was shown to be useful for the facile characterization of MOF materials during adsorption and especially, desorption. Further, the development of a Raman spectroscopic-based method of determining binary adsorption isotherms was initiated. It was discovered that a stronger base functionality will need to be added to MOF linkers in order to enhance CO{sub 2} selectivity over other gases via a chemisorption mechanism. A concentrated effort was expended on being able to accurately predict CO{sub 2} selectivities and on the calculation of predicted MOF surface area values from first principles. A method of modeling hydrolysis on MOF materials that correlates with experimental data was developed and refined. Complimentary experimental data were recorded via utilization of a combinatorial chemistry heat treatment unit and high-throughput X-ray diffractometer. The three main Deliverables for the project, namely (a) a MOF for pre-combustion (e.g., IGCC) CO{sub 2} capture, (b) a MOF for post-combustion (flue gas) CO{sub 2} capture, and (c) an assessment of commercial potential for a MOF in the IGCC application, were completed. The key properties for MOFs to work in this application - high CO{sub 2} capacity, good adsorption/desorption rates, high adsorption selectivity for CO{sub 2} over other gases such as methane and nitrogen, high stability to contaminants, namely

  12. Measurements of Surface Ocean Carbon Dioxide Partial Pressure During WOCE

    SciTech Connect

    Weiss, R.F.

    1998-10-15

    All of the technical goals of the World Ocean Circulation Experiment (WOCE) field program which were supported under the Department of Energy research grant ''Measurements of Surface Ocean Carbon Dioxide Partial Pressure During WOCE'' (DE-FG03-90ER60981) have been met. This has included the measurement of the partial pressures of carbon dioxide (C0{sub 2}) and nitrous oxide (N{sub 2}O) in both the surface ocean and the atmosphere on 24 separate shipboard expedition legs of the WOCE Hydrographic Programme. These measurements were made in the Pacific, Indian and Atlantic Oceans over a six-and-a-half year period, and over a distance of nearly 200,000 kilometers of ship track. The total number of measurements, including ocean measurements, air measurements and standard gas measurements, is about 136,000 for each gas, or about 34,000 measurements of each gas in the ocean and in the air. This global survey effort is directed at obtaining a better understanding of the role of the oceans in the global atmospheric budgets of two important natural and anthropogenic modulators of climate through the ''greenhouse effect'', CO{sub 2} and N{sub 2}O, and an important natural and anthropogenic modulator of the Earth's protective ozone layer through catalytic processes in the stratosphere, N{sub 2}O. For both of these compounds, the oceans play a major role in their global budgets. In the case of CO{sub 2}, roughly half of the anthropogenic production through the combustion of fossil fuels has been absorbed by the world's oceans. In the case of N{sub 2}O, roughly a third of the natural flux to the atmosphere originates in the oceans. As the interpretation of the variability in the oceanic distributions of these compounds improves, measurements such as those supported by this research project are playing an increasingly important role in improving our understanding of natural and anthropogenic influences on climate and ozone. (B204)

  13. Voltage and pressure scaling of streamer dynamics in a helium plasma jet with N{sub 2} co-flow

    SciTech Connect

    Leiweke, Robert J.; Ganguly, Biswa N.; Scofield, James D.

    2014-08-15

    Positive polarity applied voltage and gas pressure dependent scaling of cathode directed streamer propagation properties in helium gas flow guided capillary dielectric barrier discharge have been quantified from streamer velocity, streamer current, and streamer optical diameter measurements. All measurements of the non-stochastic streamer properties have been performed in a variable gas pressure glass cell with N{sub 2} co-flow and under self-consistent Poisson electric field dominated conditions to permit data comparison with 2-D streamer dynamics models in air/nitrogen. The streamer optical diameter was found to be nearly independent of both gas pressures, from 170 Torr up to 760 Torr, and also for applied voltages from 6 to 11 kV at 520 Torr. The streamer velocity was found to increase quadratically with increased applied voltage. These observed differences in the 2-D scaling properties of ionization wave sustained cathode directed streamer propagation in helium flow channel with N{sub 2} annular co-flow compared to the streamer propagation in air or nitrogen have been shown to be caused by the remnant ionization distribution due to large differences in the dissociative recombination rates of He{sub 2}{sup +} versus N{sub 4}{sup +} ions, for this 5 kHz repetition rate applied voltage pulse generated streamers.

  14. Evaluation of thermal helium beam and line-ratio fast diagnostic on the National Spherical Torus Experiment-Upgrade

    DOE PAGES [OSTI]

    Munoz Burgos, Jorge M.; Agostini, Matteo; Scarin, Paolo; Stotler, Daren P.; Unterberg, Ezekial A.; Loch, Stuart D.; Schmitz, Oliver; Tritz, Kevin; Stutman, Dan

    2015-05-06

    A 1-D kinetic collisional radiative model (CRM) with state-of-the-art atomic data is developed and employed to simulate line emission to evaluate the Thermal Helium Beam (THB) diagnostic on NSTX-U. This diagnostic is currently in operation on RFX-mod, and it is proposed to be installed on NSTX-U. The THB system uses the intensity ratios of neutral helium lines 667.8, 706.5, and 728.1 nm to derive electron temperature (eV ) and density (cm–3) profiles. The purpose of the present analysis is to evaluate the applications of this diagnostic for determining fast (~4 μs) electron temperature and density radial profiles on the scrape-offmore » layer (SOL) and edge regions of NSTX-U that are needed in turbulence studies. The diagnostic is limited by the level of detection of the 728.1 nm line, which is the weakest of the three. In conclusion, this study will also aid in future design of a similar 2-D diagnostic systems on the divertor.« less

  15. A comparison between characteristics of atmospheric-pressure plasma jets sustained by nanosecond- and microsecond-pulse generators in helium

    SciTech Connect

    Zhang, Cheng; Shao, Tao Wang, Ruixue; Yan, Ping; Zhou, Zhongsheng; Zhou, Yixiao

    2014-10-15

    Power source is an important parameter that can affect the characteristics of atmospheric-pressure plasma jets (APPJs), because it can play a key role on the discharge characteristics and ionization process of APPJs. In this paper, the characteristics of helium APPJs sustained by both nanosecond-pulse and microsecond-pulse generators are compared from the aspects of plume length, discharge current, consumption power, energy, and optical emission spectrum. Experimental results showed that the pulsed APPJ was initiated near the high-voltage electrode with a small curvature radius, and then the stable helium APPJ could be observed when the applied voltage increased. Moreover, the discharge current of the nanosecond-pulse APPJ was larger than that of the microsecond-pulse APPJ. Furthermore, although the nanosecond-pulse generator consumed less energy than the microsecond-pulse generator, longer plume length, larger instantaneous power per pulse and stronger spectral line intensity could be obtained in the nanosecond-pulse excitation case. In addition, some discussion indicated that the rise time of the applied voltage could play a prominent role on the generation of APPJs.

  16. Deep Burn: Development of Transuranic Fuel for High-Temperature Helium-Cooled Reactors- Monthly Highlights September 2010

    SciTech Connect

    Snead, Lance Lewis; Besmann, Theodore M; Collins, Emory D; Bell, Gary L

    2010-10-01

    The DB Program monthly highlights report for August 2010, ORNL/TM-2010/184, was distributed to program participants by email on September 17. This report discusses: (1) Core and Fuel Analysis - (a) Core Design Optimization in the HTR (high temperature helium-cooled reactor) Prismatic Design (Logos), (b) Core Design Optimization in the HTR Pebble Bed Design (INL), (c) Microfuel analysis for the DB HTR (INL, GA, Logos); (2) Spent Fuel Management - (a) TRISO (tri-structural isotropic) repository behavior (UNLV), (b) Repository performance of TRISO fuel (UCB); (3) Fuel Cycle Integration of the HTR (high temperature helium-cooled reactor) - Synergy with other reactor fuel cycles (GA, Logos); (4) TRU (transuranic elements) HTR Fuel Qualification - (a) Thermochemical Modeling, (b) Actinide and Fission Product Transport, (c) Radiation Damage and Properties; (5) HTR Spent Fuel Recycle - (a) TRU Kernel Development (ORNL), (b) Coating Development (ORNL), (c) Characterization Development and Support, (d) ZrC Properties and Handbook; and (6) HTR Fuel Recycle - (a) Graphite Recycle (ORNL), (b) Aqueous Reprocessing, (c) Pyrochemical Reprocessing METROX (metal recovery from oxide fuel) Process Development (ANL).

  17. Characterization of deuterium clusters mixed with helium gas for an application in beam-target-fusion experiments

    SciTech Connect

    Bang, W.; Quevedo, H. J.; Bernstein, A. C.; Dyer, G.; Ihn, Y. S.; Cortez, J.; Aymond, F.; Gaul, E.; Donovan, M. E.; Barbui, M.; Bonasera, A.; Natowitz, J. B.; Albright, B. J.; Fernández, J. C.; Ditmire, T.

    2014-12-10

    We measured the average deuterium cluster size within a mixture of deuterium clusters and helium gas by detecting Rayleigh scattering signals. The average cluster size from the gas mixture was comparable to that from a pure deuterium gas when the total backing pressure and temperature of the gas mixture were the same as those of the pure deuterium gas. According to these measurements, the average size of deuterium clusters depends on the total pressure and not the partial pressure of deuterium in the gas mixture. To characterize the cluster source size further, a Faraday cup was used to measure the average kinetic energy of the ions resulting from Coulomb explosion of deuterium clusters upon irradiation by an intense ultrashort pulse. The deuterium ions indeed acquired a similar amount of energy from the mixture target, corroborating our measurements of the average cluster size. As the addition of helium atoms did not reduce the resulting ion kinetic energies, the reported results confirm the utility of using a known cluster source for beam-target-fusion experiments by introducing a secondary target gas.

  18. Characterization of deuterium clusters mixed with helium gas for an application in beam-target-fusion experiments

    DOE PAGES [OSTI]

    Bang, W.; Quevedo, H. J.; Bernstein, A. C.; Dyer, G.; Ihn, Y. S.; Cortez, J.; Aymond, F.; Gaul, E.; Donovan, M. E.; Barbui, M.; et al

    2014-12-10

    We measured the average deuterium cluster size within a mixture of deuterium clusters and helium gas by detecting Rayleigh scattering signals. The average cluster size from the gas mixture was comparable to that from a pure deuterium gas when the total backing pressure and temperature of the gas mixture were the same as those of the pure deuterium gas. According to these measurements, the average size of deuterium clusters depends on the total pressure and not the partial pressure of deuterium in the gas mixture. To characterize the cluster source size further, a Faraday cup was used to measure themore » average kinetic energy of the ions resulting from Coulomb explosion of deuterium clusters upon irradiation by an intense ultrashort pulse. The deuterium ions indeed acquired a similar amount of energy from the mixture target, corroborating our measurements of the average cluster size. As the addition of helium atoms did not reduce the resulting ion kinetic energies, the reported results confirm the utility of using a known cluster source for beam-target-fusion experiments by introducing a secondary target gas.« less

  19. Temperature dependence of helium-implantation-induced lattice swelling in polycrystalline tungsten: X-ray micro-diffraction and Eigenstrain modelling

    DOE PAGES [OSTI]

    de Broglie, I.; Beck, C. E.; Liu, W.; Hofmann, Felix

    2015-05-30

    Using synchrotron X-ray micro-diffraction and Eigenstrain analysis the distribution of lattice swelling near grain boundaries in helium-implanted polycrystalline tungsten is quantified. Samples heat-treated at up to 1473 K after implantation show less uniform lattice swelling that varies significantly from grain to grain compared to as-implanted samples. An increase in lattice swelling is found in the vicinity of some grain boundaries, even at depths beyond the implanted layer. As a result, these findings are discussed in terms of the evolution of helium-ion-implantation-induced defects.

  20. DOE Selects Project to Help Advance More Efficient Supercritical Carbon Dioxide-Based Power Cycles

    Energy.gov [DOE]

    The U.S. Department of Energy’s National Energy Technology Laboratory (NETL) has selected Thar Energy, LLC to develop new recuperator technologies leading to more cost-effective and efficient supercritical carbon dioxide (SCO2)-based power cycles.