National Library of Energy BETA

Sample records for volcano sunda arc

  1. JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 88, NO. B9, PAGES 7429-7448, SEPTEMBER 10,1983 --BACK ARC THRUSTING IN THE EASTERN SUNDA ARC, INDONESIA

    E-Print Network [OSTI]

    McCaffrey, Robert

    THRUSTING IN THE EASTERN SUNDA ARC, INDONESIA: A CONSEQUENCE OF ARC-CONTINENT COLLISION Eli A. Silver Center, Jalan Diponegoro 57, Bandung, Indonesia Abstract. The structure of the eastern Sunda convergence

  2. 238U Decay Series Systematics Of Young Lavas From Batur Volcano, Sunda Arc

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental Jump to:EAand Dalton Jump to:Wylie,Information Skord, Et Al.,2050Limits,Energy|

  3. Submarine venting of liquid carbon dioxide on a Mariana Arc volcano

    E-Print Network [OSTI]

    Chadwick, Bill

    Submarine venting of liquid carbon dioxide on a Mariana Arc volcano John Lupton NOAA/Pacific Marine, Washington 98115-6349, USA Cornel de Ronde Institute of Geological and Nuclear Sciences, 30 Gracefield Road, California, 92065, USA [1] Although CO2 is generally the most abundant dissolved gas found in submarine

  4. Sunda-Java trench kinematics, slab window formation and overriding plate deformation since the Cretaceous

    E-Print Network [OSTI]

    Müller, Dietmar

    Sunda-Java trench kinematics, slab window formation and overriding plate deformation since along the 3200 km long Sunda-Java trench, one of the largest subduction systems on Earth. Combining window underlying the Java­South Sumatra region, and we propose that decreased mantle wedge viscosities

  5. Beijing Sunda Solar Energy Technology Co Ltd | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX E LIST OFAMERICA'S FUTURE.EnergyWoodenDateSAEngineeringBecosaJunda EnergyFengliSunda

  6. India and Sunda plates motion and deformation along their boundary in Myanmar determined by GPS

    E-Print Network [OSTI]

    Vigny, Christophe

    India and Sunda plates motion and deformation along their boundary in Myanmar determined by GPS with respect to mainland India. Including these points, using a longer time span than previous studies-day Indian motion. Our results confirm that the current motion of India is slower than predicted by the NUVEL

  7. Cathodic arcs

    E-Print Network [OSTI]

    Anders, Andre

    2003-01-01

    Rectangular vacuum-arc plasma source, Jan. 2, 1996. [40] A.A. Anders, Cathodic Arc Plasma Deposition (in preparation) (from the cathodic arc plasma. In most cases, a magnetic

  8. Ice-volcano interactions Eyjafjallajkull volcano, Iceland

    E-Print Network [OSTI]

    Berthier, Etienne

    Ice-volcano interactions in Eyjafjallajkull volcano, Iceland Eyjlfur Magnsson1, Magns Tumi Sciences, University of Iceland, Reykjavk, Iceland 2. Institute of Earth Sciences, University of Iceland, Reykjavk, Iceland 3. Icelandic Coast Guard SPIRIT workshop 29&30 April 2010, Toulouse Picture by Eyjlfur

  9. Architecture of the Object Oriented ARC framework

    E-Print Network [OSTI]

    Joshi, Rushikesh K.

    in the ARC logical ring ARC Sotware Components ARC Sotware Components ARC Sotware Components ARC Sotware Components ARC Sotware Components > > >

  10. Crustal-scale degassing due to magma system destabilisation and magma-gas decoupling at Soufrire Hills Volcano, Montserrat

    E-Print Network [OSTI]

    Christopher, T. E.; Blundy, J.; Cashman, K.; Cole, P.; Edmonds, M.; Smith, P. J.; Sparks, R. S. J.; Stinton, A.

    2015-06-11

    are consistent with internal modifications to the mush system, such as melt and gas migration from one level to another, but without discharge to the surface. Uranium-series isotope data indicate long crustal residence times of the andesite magma (105... for hydrothermal ore formation associated with arc volcanoes. Porphyry copper deposits are widely viewed as giant sulfur anomalies (Hunt, 1977) and are therefore likely to be related in origin to the excess sulfur phenomenon of arc volcanoes (Wallace, 2005...

  11. Validation of Innovative Exploration Technologies for Newberry Volcano: LIDAR of Newberry Volcano 2012

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Jaffe, Todd

    2012-01-01

    Validation of Innovative Exploration Technologies for Newberry Volcano: LIDAR of Newberry Volcano 2012

  12. Validation of Innovative Exploration Technologies for Newberry Volcano: LIDAR of Newberry Volcano 2012

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Jaffe, Todd

    Validation of Innovative Exploration Technologies for Newberry Volcano: LIDAR of Newberry Volcano 2012

  13. Arc Position Sensing

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

    device. Basically, an ECL can determine positions of arcs within an electric arc furnace in real time. No other measurement technique can give this kind of information....

  14. Volcanoes generate devastating waves

    SciTech Connect (OSTI)

    Lockridge, P. (National Geophysical Data Center, Boulder, CO (USA))

    1988-01-01

    Although volcanic eruptions can cause many frightening phenomena, it is often the power of the sea that causes many volcano-related deaths. This destruction comes from tsunamis (huge volcano-generated waves). Roughly one-fourth of the deaths occurring during volcanic eruptions have been the result of tsunamis. Moreover, a tsunami can transmit the volcano's energy to areas well outside the reach of the eruption itself. Some historic records are reviewed. Refined historical data are increasingly useful in predicting future events. The U.S. National Geophysical Data Center/World Data Center A for Solid Earth Geophysics has developed data bases to further tsunami research. These sets of data include marigrams (tide gage records), a wave-damage slide set, digital source data, descriptive material, and a tsunami wall map. A digital file contains information on methods of tsunami generation, location, and magnitude of generating earthquakes, tsunami size, event validity, and references. The data can be used to describe areas mot likely to generate tsunamis and the locations along shores that experience amplified effects from tsunamis.

  15. Rotating arc spark plug

    DOE Patents [OSTI]

    Whealton, John H.; Tsai, Chin-Chi

    2003-05-27

    A spark plug device includes a structure for modification of an arc, the modification including arc rotation. The spark plug can be used in a combustion engine to reduce emissions and/or improve fuel economy. A method for operating a spark plug and a combustion engine having the spark plug device includes the step of modifying an arc, the modifying including rotating the arc.

  16. DC arc weld starter

    DOE Patents [OSTI]

    Campiotti, Richard H. (Tracy, CA); Hopwood, James E. (Oakley, CA)

    1990-01-01

    A system for starting an arc for welding uses three DC power supplies, a high voltage supply for initiating the arc, an intermediate voltage supply for sustaining the arc, and a low voltage welding supply directly connected across the gap after the high voltage supply is disconnected.

  17. Volcano Hazards at Fuego and Acatenango, GuatemalaVolcano Hazards at Fuego and Acatenango, GuatemalaVolcano Hazards at Fuego and Acatenango, GuatemalaVolcano Hazards at Fuego and Acatenango, GuatemalaVolcano Hazards at Fuego and Acatenango, Guatemala 1111

    E-Print Network [OSTI]

    Rose, William I.

    Volcano Hazards at Fuego and Acatenango, GuatemalaVolcano Hazards at Fuego and Acatenango, GuatemalaVolcano Hazards at Fuego and Acatenango, GuatemalaVolcano Hazards at Fuego and Acatenango, GuatemalaVolcano Hazards at Fuego and Acatenango, Guatemala 11111 Open-File Report 01431Open-File Report 01

  18. Arc initiation in cathodic arc plasma sources

    DOE Patents [OSTI]

    Anders, Andre (Albany, CA)

    2002-01-01

    A "triggerless" arc initiation method and apparatus is based on simply switching the arc supply voltage to the electrodes (anode and cathode). Neither a mechanical trigger electrode nor a high voltage flashover from a trigger electrode is required. A conducting path between the anode and cathode is provided, which allows a hot spot to form at a location where the path connects to the cathode. While the conductive path is eroded by the cathode spot action, plasma deposition ensures the ongoing repair of the conducting path. Arc initiation is achieved by simply applying the relatively low voltage of the arc power supply, e.g. 500 V-1 kV, with the insulator between the anode and cathode coated with a conducting layer and the current at the layer-cathode interface concentrated at one or a few contact points. The local power density at these contact points is sufficient for plasma production and thus arc initiation. A conductive surface layer, such as graphite or the material being deposited, is formed on the surface of the insulator which separates the cathode from the anode. The mechanism of plasma production (and arc initiation) is based on explosive destruction of the layer-cathode interface caused by joule heating. The current flow between the thin insulator coating and cathode occurs at only a few contact points so the current density is high.

  19. Welding arc initiator

    DOE Patents [OSTI]

    Correy, T.B.

    1989-05-09

    An improved inert gas shielded tungsten arc welder is disclosed of the type wherein a tungsten electrode is shielded within a flowing inert gas, and, an arc, following ignition, burns between the energized tungsten electrode and a workpiece. The improvement comprises in combination with the tungsten electrode, a starting laser focused upon the tungsten electrode which to ignite the electrode heats a spot on the energized electrode sufficient for formation of a thermionic arc. Interference problems associated with high frequency starters are thus overcome. 3 figs.

  20. Electric arc saw apparatus

    DOE Patents [OSTI]

    Deichelbohrer, Paul R [Richland, WA

    1986-01-01

    A portable, hand held electric arc saw has a small frame for supporting an electrically conducting rotary blade which serves as an electrode for generating an electric arc to erode a workpiece. Electric current is supplied to the blade by biased brushes and a slip ring which are mounted in the frame. A pair of freely movable endless belts in the form of crawler treads stretched between two pulleys are used to facilitate movement of the electric arc saw. The pulleys are formed of dielectric material to electrically insulate the crawler treads from the frame.

  1. Origin of basalts by hybridisation in andesite-dominated arcs

    E-Print Network [OSTI]

    Cassidy, Michael; Edmonds, Marie; Watt, Sebastian F. L.; Palmer, Martin R.; Gernon, Thomas M.

    2015-02-16

    seen in the erupted magmas 428 (Cashman and Blundy, 2013). These authors suggest that magma storage systems under most 429 arc volcanoes are dominated by similar processes, where crystal mushes are fed by hotter, 430 slightly more mafic magma... (most common) and reverse zoning at the 476 rim of the crystal (Figs. 5c, 6, 7 and 12a). Many of the Group 1 olivines exhibit normal 477 zoning at the rims, consistent with magma from a primitive mush entrained into a more 478 evolved storage system...

  2. Filtered cathodic arc source

    DOE Patents [OSTI]

    Falabella, S.; Sanders, D.M.

    1994-01-18

    A continuous, cathodic arc ion source coupled to a macro-particle filter capable of separation or elimination of macro-particles from the ion flux produced by cathodic arc discharge is described. The ion source employs an axial magnetic field on a cathode (target) having tapered sides to confine the arc, thereby providing high target material utilization. A bent magnetic field is used to guide the metal ions from the target to the part to be coated. The macro-particle filter consists of two straight solenoids, end to end, but placed at 45[degree] to one another, which prevents line-of-sight from the arc spot on the target to the parts to be coated, yet provides a path for ions and electrons to flow, and includes a series of baffles for trapping the macro-particles. 3 figures.

  3. Electric arc saw apparatus

    DOE Patents [OSTI]

    Deichelbohrer, P.R.

    1983-08-08

    A portable, hand-held electric arc saw apparatus comprising a small frame for supporting an electrically conducting rotary blade which serves as an electrode for generating an electric arc between the blade and a workpiece of opposite polarity. Electrically conducting means are provided on said frame for transmitting current to said blade. A pair of freely movable endless belts in the form of crawler treads are employed to facilitate movement of the apparatus relative to the workpiece.

  4. Ion charge state fluctuations in vacuum arcs

    E-Print Network [OSTI]

    Anders, Andre; Fukuda, Kentaro; Yushkov, Georgy Yu

    2004-01-01

    known that cathodic vacuum arc plasmas contain multiple ionfunctions [16]. The arc plasma is known to be noisy, thatcondensation of cathodic arc plasma. They are also used as

  5. Arc Plasma Torch Modeling

    E-Print Network [OSTI]

    Trelles, J P; Vardelle, A; Heberlein, J V R

    2013-01-01

    Arc plasma torches are the primary components of various industrial thermal plasma processes involving plasma spraying, metal cutting and welding, thermal plasma CVD, metal melting and remelting, waste treatment and gas production. They are relatively simple devices whose operation implies intricate thermal, chemical, electrical, and fluid dynamics phenomena. Modeling may be used as a means to better understand the physical processes involved in their operation. This paper presents an overview of the main aspects involved in the modeling of DC arc plasma torches: the mathematical models including thermodynamic and chemical non-equilibrium models, turbulent and radiative transport, thermodynamic and transport property calculation, boundary conditions and arc reattachment models. It focuses on the conventional plasma torches used for plasma spraying that include a hot-cathode and a nozzle anode.

  6. The youngest eruptions and edifice collapse of Iriga volcano, Philippines

    E-Print Network [OSTI]

    Belousov, Alexander

    The youngest eruptions and edifice collapse of Iriga volcano, Philippines Alexander Belousov 1 of Volcanology and Seismology, Petropavlovsk, Russia, 3 University of Philippines Iriga volcano has a prominent

  7. Chopping effect observed at cathodic arc initiation

    E-Print Network [OSTI]

    Anders, Andre

    2000-01-01

    generation by vacuum arc plasma guns, Rev. Sci. Instrum. ,probe L L SCR C C D I arc plasma source and filter cathode Rto IEEE Trans. Plasma Science Cathodic arcs or vacuum arcs

  8. The deep structure of Axial Volcano Michael West

    E-Print Network [OSTI]

    West, Michael

    available on Web #12;The deep structure of Axial Volcano IV. Magma Reservoir beneath Axial Volcano AxialThe deep structure of Axial Volcano Michael West Thesis defense, June 4, 2001 #12;Motivation What at Axial may be interpreted (NeMO, Neptune) #12;The deep structure of Axial Volcano IV. Magma Reservoir

  9. Arc Position Sensing Technology

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O O D SFederal8823 Revision 02 (CRACApril JanuaryAps_notifyArc

  10. Cathodic Arc Plasma Deposition

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield MunicipalTechnical Report: Achievements ofCOMPOSITION OF VAPORS FROM BOILING NITRIC ACIDCathodic Arc

  11. Volcano-earthquake interaction at Mauna Loa volcano, Hawaii Thomas R. Walter1,2

    E-Print Network [OSTI]

    Amelung, Falk

    Volcano-earthquake interaction at Mauna Loa volcano, Hawaii Thomas R. Walter1,2 and Falk Amelung1 into the Southwest Rift Zone (SWRZ) or into the Northeast Rift Zone (NERZ) and by large earthquakes at the basal decollement fault. In this paper we examine the historic eruption and earthquake catalogues, and we test

  12. Cathodic Vacuum Arc Plasma of Thallium

    E-Print Network [OSTI]

    Yushkov, Georgy Yu.; Anders, Andre

    2006-01-01

    P. J. Martin, Handbook of Vacuum Arc Science and Technology.charge state distributions of vacuum arc plasmas: The originand the broadening of vacuum-arc ion charge state

  13. Cathodic Vacuum Arc Plasma of Thallium

    E-Print Network [OSTI]

    Yushkov, Georgy Yu.; Anders, Andre

    2006-01-01

    distributions of vacuum arc plasmas: The origin of species,"spectrum for thallium arc plasma, as measured for 400 A,and thallium vacuum arc plasmas. For comparison, the data

  14. Arc fault detection system

    DOE Patents [OSTI]

    Jha, Kamal N. (Bethel Park, PA)

    1999-01-01

    An arc fault detection system for use on ungrounded or high-resistance-grounded power distribution systems is provided which can be retrofitted outside electrical switchboard circuits having limited space constraints. The system includes a differential current relay that senses a current differential between current flowing from secondary windings located in a current transformer coupled to a power supply side of a switchboard, and a total current induced in secondary windings coupled to a load side of the switchboard. When such a current differential is experienced, a current travels through a operating coil of the differential current relay, which in turn opens an upstream circuit breaker located between the switchboard and a power supply to remove the supply of power to the switchboard.

  15. Arc fault detection system

    DOE Patents [OSTI]

    Jha, K.N.

    1999-05-18

    An arc fault detection system for use on ungrounded or high-resistance-grounded power distribution systems is provided which can be retrofitted outside electrical switchboard circuits having limited space constraints. The system includes a differential current relay that senses a current differential between current flowing from secondary windings located in a current transformer coupled to a power supply side of a switchboard, and a total current induced in secondary windings coupled to a load side of the switchboard. When such a current differential is experienced, a current travels through a operating coil of the differential current relay, which in turn opens an upstream circuit breaker located between the switchboard and a power supply to remove the supply of power to the switchboard. 1 fig.

  16. AN ISOTOPE HYDROLOGY STUDY OF THE KILAUEA VOLCANO AREA, HAWAII

    E-Print Network [OSTI]

    AN ISOTOPE HYDROLOGY STUDY OF THE KILAUEA VOLCANO AREA, HAWAII STUDY OF THE KILAUEA VOLCANO AREA, HAWAII M.A. Scholl, S.E. Ingebritsen, C.J. Janik, and J.P. Kauahikaua

  17. Short communication Observations of eruptive activity at Santiaguito volcano, Guatemala

    E-Print Network [OSTI]

    Rose, William I.

    Short communication Observations of eruptive activity at Santiaguito volcano, Guatemala Gregg J volcano, Guatemala, from the vantage point of its parent, Santa Maria. We have taken 12 h of digital

  18. The origin of the Hawaiian Volcano Observatory

    SciTech Connect (OSTI)

    Dvorak, John [University of Hawaii's Institute for Astronomy (United States)

    2011-05-15

    I first stepped through the doorway of the Hawaiian Volcano Observatory in 1976, and I was impressed by what I saw: A dozen people working out of a stone-and-metal building perched at the edge of a high cliff with a spectacular view of a vast volcanic plain. Their primary purpose was to monitor the island's two active volcanoes, Kilauea and Mauna Loa. I joined them, working for six weeks as a volunteer and then, years later, as a staff scientist. That gave me several chances to ask how the observatory had started.

  19. Hydrologic Modeling with Arc Hydro Tools 1 Copyright 2007 ESRI. All rights reserved. Arc Hydro

    E-Print Network [OSTI]

    Slatton, Clint

    Hydrologic Modeling with Arc Hydro Tools 1 Copyright © 2007 ESRI. All rights reserved. Arc Hydro Arc Hydro: GIS in Water Resources Seminar/Workshop Gainesville, Florida ­ November 15, 2007 Christine Dartiguenave, ESRI inc. cdartiguenave@esri.com #12;Hydrologic Modeling with Arc Hydro Tools 2 2Arc Hydro

  20. Percussive arc welding apparatus

    DOE Patents [OSTI]

    Hollar, Jr., Donald L. (Overland Park, KS)

    2002-01-01

    A percussive arc welding apparatus includes a generally cylindrical actuator body having front and rear end portions and defining an internal recess. The front end of the body includes an opening. A solenoid assembly is provided in the rear end portion in the internal recess of the body, and an actuator shaft assembly is provided in the front end portion in the internal recess of the actuator body. The actuator shaft assembly includes a generally cylindrical actuator block having first and second end portions, and an actuator shaft having a front end extending through the opening in the actuator body, and the rear end connected to the first end portion of the actuator block. The second end portion of the actuator block is in operational engagement with the solenoid shaft by a non-rigid connection to reduce the adverse rebound effects of the actuator shaft. A generally transversely extending pin is rigidly secured to the rear end of the shaft. One end of the pin is received in a slot in the nose housing sleeve to prevent rotation of the actuator shaft during operation of the apparatus.

  1. PUBLICATIONS OF THE VOLCANO HAZARDS PROGRAM

    E-Print Network [OSTI]

    : Geophysical Research Letters, v. 25, p. 3397-3400. Bacon, C. R., Bruggman, P. E., Christiansen, R. L., Clynne-423. Bacon, C. R., Gunn, S. H., Lanphere, M. A., and Wooden, J. L., 1994, Multiple isotopic components-1556. Bacon, C. R., Mastin, L. G., Scott, K. M., and Nathenson, Manuel, 1997, Volcano and earthquake hazards

  2. Cathodic Arc Deposition of Copper Oxide Thin Films

    E-Print Network [OSTI]

    MacGill, R.A.

    2011-01-01

    compatibility. A cathodic arc plasma source with a copperon operating a cathodic arc plasma source with a copperdeposited using a cathodic arc plasma source with a copper

  3. Ion energy distribution functions of vacuum arc plasmas

    E-Print Network [OSTI]

    Byon, Eungsun; Anders, Andre

    2002-01-01

    functions of vacuum arc plasmas Eungsun Byon and Andrfunctions of vacuum arc plasmas Eungsun Byon and Andrenergies of vacuum arc plasmas 1-7 because these energies

  4. The fractal nature of vacuum arc cathode spots

    E-Print Network [OSTI]

    Anders, Andre

    2005-01-01

    functions of vacuum arc plasmas," J. Appl. Phys. , vol. 93,macroparticles in vacuum arc plasmas," in preparation, 2005.A. Anders, Cathodic Arc Plasma Deposition: From Fractal

  5. Cathodic Arcs: Fractal Voltage and Cohesive Energy Rule

    E-Print Network [OSTI]

    Anders, Andre; Oks, Efim M.; Gera, Yu. Yushkov

    2005-01-01

    Applications of Vacuum-Arc-Produced Plasma, Ion and Electronparameters of cathodic arc plasma, many researches decidedof a coaxial cathodic arc plasma source, and analyzing the

  6. Physics of arcing, and implications to sputter deposition

    E-Print Network [OSTI]

    Anders, Andre

    2005-01-01

    A. Anders, Cathodic Arc Plasma Deposition: From FractalApplications of Vacuum-Arc-Produced Plasma, Ion and Electronstandard) textbooks on plasmas [1], arcs are introduced as

  7. NEUTRAL-BEAM PLASMA SOURCE METAL-ARC PROTECTION CIRCUIT

    E-Print Network [OSTI]

    deVries, G.J.

    2010-01-01

    e r . METAL ARCS IN PLASMAS Metal-arcs in plasma sources are1981 NEUTRAL-BEAM PLASMA SOURCE METAL-ARC PROTECTION CIRCUIT48 NEUTRAL-BEAM PLASMA SOURCE METAL-ARC PROTECTION CIRCUIT*

  8. Reducing ion beam noise of vacuum arc ion sources

    E-Print Network [OSTI]

    Anders, Andre; Hollinger, Ralph

    2001-01-01

    in the expanding vacuum arc plasma and operating in the ion3 Schematic of the vacuum arc plasma generator (arc cathodeUnfortunately, vacuum arc plasmas are rapidly fluctuating

  9. Using Arc Marine in ArcGIS 10 Tutorial for Beginners

    E-Print Network [OSTI]

    Wright, Dawn Jeannine

    Using Arc Marine in ArcGIS 10 Tutorial for Beginners Introduction Arc Marine (or the ArcGIS Marine Data Model - MDM), is a geodatabase model tailored specifically for the marine GIS community. Created by researchers from Oregon State University, Duke

  10. Geothermal Exploration of Newberry Volcano, Oregon

    SciTech Connect (OSTI)

    Waibel, Albert F.; Frone, Zachary S.; Blackwell, David D.

    2014-12-01

    Davenport Newberry (Davenport) has completed 8 years of exploration for geothermal energy on Newberry Volcano in central Oregon. Two deep exploration test wells were drilled by Davenport on the west flank of the volcano, one intersected a hydrothermal system; the other intersected isolated fractures with no hydrothermal interconnection. Both holes have bottom-hole temperatures near or above 315C (600F). Subsequent to deep test drilling an expanded exploration and evaluation program was initiated. These efforts have included reprocessing existing data, executing multiple geological, geophysical, geochemical programs, deep exploration test well drilling and shallow well drilling. The efforts over the last three years have been made possible through a DOE Innovative Exploration Technology (IET) Grant 109, designed to facilitate innovative geothermal exploration techniques. The combined results of the last 8 years have led to a better understanding of the history and complexity of Newberry Volcano and improved the design and interpretation of geophysical exploration techniques with regard to blind geothermal resources in volcanic terrain.

  11. Arc$c Climate Dynamics James Overland

    E-Print Network [OSTI]

    Carbon Chemistry- Mathis, Evans, Cross Pacific Ecosystems- Stabeno, Moore, Mordy than in other regions of the globe (Arc%c Amplifica%on) Arc partnerships Contributed to wri$ng of the NOAA Arc%c Vision and Strategy Plan Part

  12. Aster Watches The World'S Volcanoes- A New Paradigm For Volcanological...

    Open Energy Info (EERE)

    Volcanoes- A New Paradigm For Volcanological Observations From Orbit Abstract Onboard NASA Terra spacecraft is one of the most sophisticated earth observing instruments ever...

  13. Characterization of arcs in frequency domain

    SciTech Connect (OSTI)

    D'Inca, R.; Siegl, G.; Faugel, H.; Braun, F.; Eckert, B.; Bobkov, V.; El Khaldi, M.; Noterdaeme, J.-M.

    2009-11-26

    Arc detection systems are developed for ICRH on ITER to prevent arcs from damaging the RF components. One of the detectors, the Sub-Harmonic Arc Detector (SHAD) is based on the detection of the frequencies emitted in the MHz range by arcs [R1]. To ensure the high level of reliability required for this safety system, it is necessary to demonstrate that these frequencies present a signal with a Signal to Noise Ratio high enough to be detected under the wide range of operational conditions (frequency, power, configuration) and for the different types of arcs that can appear in the feeding lines and on the antennas (vacuum arc, glow discharge, multipactor-induced discharge). For each type of arc, we analyze the evolution of the frequency spectrum relative to the evolution of other electrical parameters (reflected power, voltage)

  14. Title: ArcAtlas Data Creator /

    E-Print Network [OSTI]

    (Subject): Frost, Precipitation, Air Temperature, Solar Radiation, Glaciers, Ground Water, Permafrost, Snow Cover, Hydrology, Volcanoes, Tectonic Pates, Agriculture, Landscape, Land Use, Soils, Vegetation, Rocks, Minerals, Population, Political Boundaries, Pipelines, Transportation, Earthquakes, Urban Areas, Wildlife

  15. When mud volcanoes sleep: Insight from seep geochemistry at the Dashgil mud volcano, Azerbaijan

    E-Print Network [OSTI]

    Svensen, Henrik

    Petroleum Research, Oslo Research Park, 0349 Oslo, Norway c Geology Institute Azerbaijan, Husein Avenue 29A, and petroleum. However, the source of the fluids and the fluidrock interactions within the mud volcano conduit and Indonesia (e.g. Jakubov et al.,1971; Barber et al.,1986; Cita et al.,1996; Dia et al., 1999; Isaksen et al

  16. Filters for cathodic arc plasmas

    DOE Patents [OSTI]

    Anders, Andre (Albany, CA); MacGill, Robert A. (Richmond, CA); Bilek, Marcela M. M. (Engadine, AU); Brown, Ian G. (Berkeley, CA)

    2002-01-01

    Cathodic arc plasmas are contaminated with macroparticles. A variety of magnetic plasma filters has been used with various success in removing the macroparticles from the plasma. An open-architecture, bent solenoid filter, with additional field coils at the filter entrance and exit, improves macroparticle filtering. In particular, a double-bent filter that is twisted out of plane forms a very compact and efficient filter. The coil turns further have a flat cross-section to promote macroparticle reflection out of the filter volume. An output conditioning system formed of an expander coil, a straightener coil, and a homogenizer, may be used with the magnetic filter for expanding the filtered plasma beam to cover a larger area of the target. A cathodic arc plasma deposition system using this filter can be used for the deposition of ultrathin amorphous hard carbon (a-C) films for the magnetic storage industry.

  17. Charge state dependence of cathodic vacuum arc ion energy and velocity distributions

    E-Print Network [OSTI]

    Rosen, Johanna; Schneider, Jochen M.; Anders, Andre

    2006-01-01

    velocity in vacuum arc plasmas by arc current perturbationin aluminum vacuum arc plasma. We show that the conflictingdistinguished. Cathodic vacuum arc plasma is well known to

  18. Plasma arc torch with coaxial wire feed

    DOE Patents [OSTI]

    Hooper, Frederick M (Albuquerque, NM)

    2002-01-01

    A plasma arc welding apparatus having a coaxial wire feed. The apparatus includes a plasma arc welding torch, a wire guide disposed coaxially inside of the plasma arc welding torch, and a hollow non-consumable electrode. The coaxial wire guide feeds non-electrified filler wire through the tip of the hollow non-consumable electrode during plasma arc welding. Non-electrified filler wires as small as 0.010 inches can be used. This invention allows precision control of the positioning and feeding of the filler wire during plasma arc welding. Since the non-electrified filler wire is fed coaxially through the center of the plasma arc torch's electrode and nozzle, the wire is automatically aimed at the optimum point in the weld zone. Therefore, there is no need for additional equipment to position and feed the filler wire from the side before or during welding.

  19. Magnetic-cusp, cathodic-arc source

    DOE Patents [OSTI]

    Falabella, Steven (Livermore, CA)

    1995-01-01

    A magnetic-cusp for a cathodic-arc source wherein the arc is confined to the desired cathode surface, provides a current path for electrons from the cathode to the anode, and utilizes electric and magnetic fields to guide ions from the cathode to a point of use, such as substrates to be coated. The magnetic-cusp insures arc stability by an easy magnetic path from anode to cathode, while the straight-through arrangement leads to high ion transmission.

  20. Arc Geometry and Algebra: Foliations, Moduli Spaces, String ...

    E-Print Network [OSTI]

    2012-05-02

    yields a modular operad structure on the homology level. .... 1.4.2 Elements as weighted arc families A weight function wt on an arc family ...... Figure 6. I, the identity and II, the arc family ? yielding the BV operator ..... weighted arc family obtained by scaling all weights of arcs incident to ?i of ? homoge- ..... A careful analysis.

  1. Metals purification by improved vacuum arc remelting

    DOE Patents [OSTI]

    Zanner, Frank J. (Sandia Park, NM); Williamson, Rodney L. (Albuquerque, NM); Smith, Mark F. (Albuquerque, NM)

    1994-12-13

    The invention relates to improved apparatuses and methods for remelting metal alloys in furnaces, particularly consumable electrode vacuum arc furnaces. Excited reactive gas is injected into a stationary furnace arc zone, thus accelerating the reduction reactions which purify the metal being melted. Additionally, a cooled condensation surface is disposed within the furnace to reduce the partial pressure of water in the furnace, which also fosters the reduction reactions which result in a purer produced ingot. Methods and means are provided for maintaining the stationary arc zone, thereby reducing the opportunity for contaminants evaporated from the arc zone to be reintroduced into the produced ingot.

  2. Gamma-Normal Probability Distribution Arc Length

    E-Print Network [OSTI]

    Hesam

    2014-11-04

    ... Engineering, Mazandaran University of Science and Technology, Babol, Iran ... the arcs are assumed to represent transportation time or cost rather than the...

  3. Miniaturized cathodic arc plasma source

    DOE Patents [OSTI]

    Anders, Andre (Albany, CA); MacGill, Robert A. (Richmond, CA)

    2003-04-15

    A cathodic arc plasma source has an anode formed of a plurality of spaced baffles which extend beyond the active cathode surface of the cathode. With the open baffle structure of the anode, most macroparticles pass through the gaps between the baffles and reflect off the baffles out of the plasma stream that enters a filter. Thus the anode not only has an electrical function but serves as a prefilter. The cathode has a small diameter, e.g. a rod of about 1/4 inch (6.25 mm) diameter. Thus the plasma source output is well localized, even with cathode spot movement which is limited in area, so that it effectively couples into a miniaturized filter. With a small area cathode, the material eroded from the cathode needs to be replaced to maintain plasma production. Therefore, the source includes a cathode advancement or feed mechanism coupled to cathode rod. The cathode also requires a cooling mechanism. The movable cathode rod is housed in a cooled metal shield or tube which serves as both a current conductor, thus reducing ohmic heat produced in the cathode, and as the heat sink for heat generated at or near the cathode. Cooling of the cathode housing tube is done by contact with coolant at a place remote from the active cathode surface. The source is operated in pulsed mode at relatively high currents, about 1 kA. The high arc current can also be used to operate the magnetic filter. A cathodic arc plasma deposition system using this source can be used for the deposition of ultrathin amorphous hard carbon (a-C) films for the magnetic storage industry.

  4. Groundwater Modeling in ArcView: by integrating ArcView, MODFLOW and

    E-Print Network [OSTI]

    Sengupta, Raja

    Groundwater Modeling in ArcView: by integrating ArcView, MODFLOW and MODPATH Abstract Modeling. This paper addresses groundwater modeling which is one of the many entities in environmental modeling in ArcView 3.2a. The objective was to create an integrated system where a user could do groundwater

  5. Asymmetric injection of cathodic arc plasma into a macroparticle filter

    E-Print Network [OSTI]

    Anders, Andre; MacGill, Robert A.

    2004-01-01

    setup. The cathodic arc plasma source is flange-mounted andfirewall" twist filter arc plasma source F IG. 1 Current (A)Injection of Cathodic Arc Plasma into a Macroparticle Filter

  6. Filtered cathodic arc deposition with ion-species-selective bias

    E-Print Network [OSTI]

    Anders, Andre; Pasaja, Nitisak; Sansongsiri, Sakon; Lim, Sunnie H.N.

    2006-01-01

    Photograph of a cathodic arc plasma source with two cathodesof ions of cathodic arc plasmas. The selection was made forAbstract A dual-cathode arc plasma source was combined with

  7. MULTIPLY STRIPPED ION GENERATION IN THE METAL VAPOR VACUUM ARC

    E-Print Network [OSTI]

    Brown, I.G.

    2010-01-01

    the metal vapor vacuum arc plasma discharge. A new kind offrom a metal vapor vacuum arc plasma has been used to obtaindrives the vacuum arc plasma is created. The fundamental

  8. Measurement of total ion current from vacuum arc plasma sources

    E-Print Network [OSTI]

    Oks, Efim M.; Savkin, Konstantin P.; Yushkov, Georgiu Yu.; Nikolaev, Alexey G.; Anders, A.; Brown, Ian G.

    2005-01-01

    A. Anders, Cathodic Arc Plasma Deposition: From Fractalion current from vacuum arc plasma sources E. M. Oks, K. P.ion current from vacuum arc plasma sources E. M. Oks, K. P.

  9. Vacuum Arc Ion Sources: Recent Developments and Applications

    E-Print Network [OSTI]

    Brown, Ian; Oks, Efim

    2005-01-01

    charge states in vacuum arc plasmas using a 'current spike'of pulsed vacuum arc plasmas in strong magnetic fields",of electrons in vacuum arc plasmas", Rev. Sci. Instrum. ,

  10. Measurement of total ion flux in vacuum Arc discharges

    E-Print Network [OSTI]

    Anders, Andre; Oks, Efim M.; Yushkov, Georgy Yu.; Brown, Ian G.

    2004-01-01

    in high current vacuum arc plasma in a magnetic field," IEEEdistributions of vacuum arc plasmas: The origin of species,"high-current vacuum arc plasmas," IEEE Trans. Plasma Sci. ,

  11. Purification of tantalum by plasma arc melting

    DOE Patents [OSTI]

    Dunn, Paul S. (Santa Fe, NM); Korzekwa, Deniece R. (Los Alamos, NM)

    1999-01-01

    Purification of tantalum by plasma arc melting. The level of oxygen and carbon impurities in tantalum was reduced by plasma arc melting the tantalum using a flowing plasma gas generated from a gas mixture of helium and hydrogen. The flowing plasma gases of the present invention were found to be superior to other known flowing plasma gases used for this purpose.

  12. Newberry Volcano EGS Demonstration - Phase I Results

    SciTech Connect (OSTI)

    William L. Osborn, Susan Petty, Trenton T. Cladouhos, Joe Iovenitti, Laura Nofziger, Owen Callahan, Douglas S. Perry and Paul L. Stern

    2011-10-23

    Phase I of the Newberry Volcano Enhanced Geothermal System (EGS) Demonstration included permitting, community outreach, seismic hazards analysis, initial microseismic array deployment and calibration, final MSA design, site characterization, and stimulation planning. The multi-disciplinary Phase I site characterization supports stimulation planning and regulatory permitting, as well as addressing public concerns including water usage and induced seismicity. A review of the project'????s water usage plan by an independent hydrology consultant found no expected impacts to local stakeholders, and recommended additional monitoring procedures. The IEA Protocol for Induced Seismicity Associated with Enhanced Geothermal Systems was applied to assess site conditions, properly inform stakeholders, and develop a comprehensive mitigation plan. Analysis of precision LiDAR elevation maps has concluded that there is no evidence of recent faulting near the target well. A borehole televiewer image log of the well bore revealed over three hundred fractures and predicted stress orientations. No natural, background seismicity has been identified in a review of historic data, or in more than seven months of seismic data recorded on an array of seven seismometers operating around the target well. A seismic hazards and induced seismicity risk assessment by an independent consultant concluded that the Demonstration would contribute no additional risk to residents of the nearest town of La Pine, Oregon. In Phase II of the demonstration, an existing deep hot well, NWG 55-29, will be stimulated using hydroshearing techniques to create an EGS reservoir. The Newberry Volcano EGS Demonstration is allowing geothermal industry and academic experts to develop, validate and enhance geoscience and engineering techniques, and other procedures essential to the expansion of EGS throughout the country. Successful development will demonstrate to the American public that EGS can play a significant role in reducing foreign energy dependence, and provide clean, renewable, baseload geothermal power generation in the State of Oregon.

  13. Chemistry of spring and well waters on Kilauea Volcano, Hawaii...

    Open Energy Info (EERE)

    Chemistry of spring and well waters on Kilauea Volcano, Hawaii, and vicinity Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Chemistry of spring...

  14. Analysis Of Multiple Scattering At Vesuvius Volcano, Italy, Using...

    Open Energy Info (EERE)

    Of Multiple Scattering At Vesuvius Volcano, Italy, Using Data Of The Tomoves Active Seismic Experiment Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal...

  15. Three-dimensional modeling of the plasma arc in arc welding

    SciTech Connect (OSTI)

    Xu, G.; Tsai, H. L.; Hu, J.

    2008-11-15

    Most previous three-dimensional modeling on gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW) focuses on the weld pool dynamics and assumes the two-dimensional axisymmetric Gaussian distributions for plasma arc pressure and heat flux. In this article, a three-dimensional plasma arc model is developed, and the distributions of velocity, pressure, temperature, current density, and magnetic field of the plasma arc are calculated by solving the conservation equations of mass, momentum, and energy, as well as part of the Maxwell's equations. This three-dimensional model can be used to study the nonaxisymmetric plasma arc caused by external perturbations such as an external magnetic field. It also provides more accurate boundary conditions when modeling the weld pool dynamics. The present work lays a foundation for true three-dimensional comprehensive modeling of GTAW and GMAW including the plasma arc, weld pool, and/or electrode.

  16. Low voltage arc formation in railguns

    DOE Patents [OSTI]

    Hawke, Ronald S. (Livermore, CA)

    1987-01-01

    A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile.

  17. Low voltage arc formation in railguns

    DOE Patents [OSTI]

    Hawke, R.S.

    1985-08-05

    A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile.

  18. Low voltage arc formation in railguns

    DOE Patents [OSTI]

    Hawke, R.S.

    1987-11-17

    A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile. 2 figs.

  19. Nitrogen Control in Electric Arc Furnace Steelmaking by Direct...

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

    Nitrogen Control in Electric Arc Furnace Steelmaking by Direct Reduced Iron Fines Injection Nitrogen Control in Electric Arc Furnace Steelmaking by Direct Reduced Iron Fines...

  20. Boron nitride ablation studies in arc jet facilities (Conference...

    Office of Scientific and Technical Information (OSTI)

    Boron nitride ablation studies in arc jet facilities Citation Details In-Document Search Title: Boron nitride ablation studies in arc jet facilities You are accessing a document...

  1. Magnetic-cusp, cathodic-arc source

    DOE Patents [OSTI]

    Falabella, S.

    1995-11-21

    A magnetic-cusp for a cathodic-arc source wherein the arc is confined to the desired cathode surface, provides a current path for electrons from the cathode to the anode, and utilizes electric and magnetic fields to guide ions from the cathode to a point of use, such as substrates to be coated. The magnetic-cusp insures arc stability by an easy magnetic path from anode to cathode, while the straight-through arrangement leads to high ion transmission. 3 figs.

  2. Newberry Volcano EGS Demonstration Stimulation Modeling

    SciTech Connect (OSTI)

    Trenton T. Cladouhos, Matthew Clyne, Maisie Nichols,; Susan Petty, William L. Osborn, Laura Nofziger

    2011-10-23

    As a part of Phase I of the Newberry Volcano EGS Demonstration project, several data sets were collected to characterize the rock volume around the well. Fracture, fault, stress, and seismicity data has been collected by borehole televiewer, LiDAR elevation maps, and microseismic monitoring. Well logs and cuttings from the target well (NWG 55-29) and core from a nearby core hole (USGS N-2) have been analyzed to develop geothermal, geochemical, mineralogical and strength models of the rock matrix, altered zones, and fracture fillings (see Osborn et al., this volume). These characterization data sets provide inputs to models used to plan and predict EGS reservoir creation and productivity. One model used is AltaStim, a stochastic fracture and flow software model developed by AltaRock. The software's purpose is to model and visualize EGS stimulation scenarios and provide guidance for final planning. The process of creating an AltaStim model requires synthesis of geologic observations at the well, the modeled stress conditions, and the stimulation plan. Any geomechanical model of an EGS stimulation will require many assumptions and unknowns; thus, the model developed here should not be considered a definitive prediction, but a plausible outcome given reasonable assumptions. AltaStim is a tool for understanding the effect of known constraints, assumptions, and conceptual models on plausible outcomes.

  3. Motion characteristics of long ac arcs in atmospheric air

    SciTech Connect (OSTI)

    Gu Shanqiang; He Jinliang; Zeng Rong; Zhang Bo; Xu Guozheng; Chen Weijiang

    2007-01-29

    Experiments on the motion of long alternating current arcs in atmospheric air show that the anode and cathode arc roots have different motion characteristics because of different formation mechanisms. During a half cycle of the arc current, the anode arc root moves towards the direction of magnetic force and occasionally has a jumping motion, while the cathode arc root moves sufficiently slow to consider it stationary and hardly has any jump. The arc column has a complex shape and moves under the drive of the magnetic force and is also quickened by the lower arc root.

  4. Detection of arcs in automotive electrical systems

    E-Print Network [OSTI]

    Mishrikey, Matthew David

    2005-01-01

    At the present time, there is no established method for the detection of DC electric arcing. This is a concern for forthcoming advanced automotive electrical systems which consist of higher DC electric power bus voltages, ...

  5. Hawley ArcGIS Desktop III: GIS Workflows and Analysis Page 1 ArcGIS Desktop III

    E-Print Network [OSTI]

    Bier, Martin

    Hawley ArcGIS Desktop III: GIS Workflows and Analysis Page 1 ArcGIS Desktop III: GIS Workflows and Analysis Overview This 2-day course builds on the skills and knowledge taught in ArcGIS Desktop II: Tools a challenging analysis project. Audience This course is for experienced ArcGIS users who want to learn more

  6. ArcGIS Explorer Online Extended Use Quick Guide ArcGIS Explorer Online--GIS for Everyone

    E-Print Network [OSTI]

    Wright, Dawn Jeannine

    ArcGIS Explorer Online Extended Use Quick Guide ArcGIS Explorer Online--GIS for Everyone Creating notes, photo links, and presentations ArcGIS Explorer Online (AGXO) is a browser-based GIS viewer, perform queries and create presentations. This quick guide is an extension of the Introduction to ArcGIS

  7. Klystron Gun Arcing and Modulator Protection

    SciTech Connect (OSTI)

    Gold, S

    2004-05-04

    The demand for 500 kV and 265 amperes peak to power an X-Band klystron brings up protection issues for klystron faults and the energy dumped into the arc from the modulator. This situation is made worse when more than one klystron will be driven from a single modulator, such as the existing schemes for running two and eight klystrons. High power pulsed klystrons have traditionally be powered by line type modulators which match the driving impedance with the load impedance and therefore current limit at twice the operating current. Multiple klystrons have the added problems of a lower modulator source impedance and added stray capacitance, which converts into appreciable energy at high voltages like 500kV. SLAC has measured the energy dumped into klystron arcs in a single and dual klystron configuration at the 400 to 450 kV level and found interesting characteristics in the arc formation. The author will present measured data from klystron arcs powered from line-type modulators in several configurations. The questions arise as to how the newly designed solid-state modulators, running multiple tubes, will react to a klystron arc and how much energy will be dumped into the arc.

  8. Ion source with improved primary arc collimation

    DOE Patents [OSTI]

    Dagenhart, William K. (Oak Ridge, TN)

    1985-01-01

    An improved negative ion source is provided in which a self-biasing, molybdenum collimator is used to define the primary electron stream arc discharge from a filament operated at a negative potential. The collimator is located between the anode and the filament. It is electrically connected to the anode by means of an appropriate size resistor such that the collimator is biased at essentially the filament voltage during operation. Initially, the full arc voltage appears across the filament to collimator until the arc discharge strikes. Then the collimator biases itself to essentially filament potential due to current flow through the resistor thus defining the primary electron stream without intercepting any appreciable arc power. The collimator aperture is slightly smaller than the anode aperture to shield the anode from the arc power, thereby preventing the exposure of the anode to the full arc power which, in the past, has caused overheating and erosion of the anode collimator during extended time pulsed-beam operation of the source. With the self-biasing collimator of this invention, the ion source may be operated from short pulse periods to steady-state without destroying the anode.

  9. REDUCING THE RISK FROM VOLCANO HAZARDS Lahars of Mount Pinatubo, Philippines

    E-Print Network [OSTI]

    REDUCING THE RISK FROM VOLCANO HAZARDS O Lahars of Mount Pinatubo, Philippines n June 15, 1991 Pinatubo on the island of Luzon in the Philippines, the volcano had been dormant for 500 years, allowing in the Philippines (Clark Air Base), were built on the broad gentle slopes surrounding the volcano. When Pinatubo

  10. Increase of shear wave velocity before the 1998 eruption of Merapi volcano (Indonesia)

    E-Print Network [OSTI]

    Snieder, Roel

    Increase of shear wave velocity before the 1998 eruption of Merapi volcano (Indonesia) U. Wegler,1 of the edifice of Merapi volcano (Java, Indonesia) before its eruption in 1998 by analyzing multiply scattered eruption of Merapi volcano (Indonesia), Geophys. Res. Lett., 33, L09303, doi:10.1029/2006GL025928. 1

  11. Investigation of the Dashigil mud volcano (Azerbaijan) using beryllium-10 K.J. Kim a,

    E-Print Network [OSTI]

    Investigation of the Dashigil mud volcano (Azerbaijan) using beryllium-10 K.J. Kim a, , M. Baskaran: Mud volcano Hydrothermal Beryllium-10 Beryllium isotopes Subduction Cosmogenic nuclide a b s t r a c Caucasus Mountains and 160 marine volcanoes (Fig. 1). Beryllium isotopes have been extensively utilized

  12. ABSTRACT. Keyhole plasma arc welding is a unique arc welding process for deep

    E-Print Network [OSTI]

    Zhang, YuMing

    ABSTRACT. Keyhole plasma arc welding is a unique arc welding process for deep penetration. To ensure the quality of the welds, the presence of the keyhole is crit- ical. Understanding of the keyhole will certainly benefit the improvement of the process and weld quality. Currently, the size of the keyhole

  13. Effects of shielding gas compositions on arc plasma and metal transfer in gas metal arc welding

    SciTech Connect (OSTI)

    Rao, Z. H.; Liao, S. M.; Tsai, H. L.

    2010-02-15

    This article presents the effects of shielding gas compositions on the transient transport phenomena, including the distributions of temperature, flow velocity, current density, and electromagnetic force in the arc and the metal, and arc pressure in gas metal arc welding of mild steel at a constant current input. The shielding gas considered includes pure argon, 75% Ar, 50% Ar, and 25% Ar with the balance of helium. It is found that the shielding gas composition has significant influences on the arc characteristics; droplet formation, detachment, transfer, and impingement onto the workpiece; and weld pool dynamics and weld bead profile. As helium increases in the shielding gas, the droplet size increases but the droplet detachment frequency decreases. For helium-rich gases, the current converges at the workpiece with a 'ring' shape which produces non-Gaussian-like distributions of arc pressure and temperature along the workpiece surface. Detailed explanations to the physics of the very complex but interesting transport phenomena are given.

  14. Vacuum Arc Melting Unit Arc Melting is used for melting metals typically to form alloys. Heating is via an electric arc struck

    E-Print Network [OSTI]

    Subramaniam, Anandh

    Vacuum Arc Melting Unit Arc Melting is used for melting metals typically to form alloys. Heating unit is used as a power source. Heat generated by the electric arc struck between the electrode unit. The vacuum unit with rotary and diffusion pumps can attain a vacuum of 106 m bar. The cold

  15. Validation of Innovative Exploration Technologies for Newberry Volcano: Map showing location of wells permitted, drilled and seismic test 2012

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Jaffe, Todd

    2012-01-01

    Innovative Exploration Technologies for Newberry Volcano: Map showing location of wells permitted, drilled & seismic test, 2012

  16. Validation of Innovative Exploration Technologies for Newberry Volcano: Map showing location of wells permitted, drilled and seismic test 2012

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Jaffe, Todd

    Innovative Exploration Technologies for Newberry Volcano: Map showing location of wells permitted, drilled & seismic test, 2012

  17. 238 U/232Th zircon geochronology for the most recent eruptions of El Chichn volcano (Chiapas, Mexico)

    E-Print Network [OSTI]

    Pack, Brenda

    2015-01-01

    predates what is recorded in eruptive stratigraphy.Chichn volcano and stratigraphy based on previous studies.

  18. Charge state and time resolved plasma composition of a pulsed zirconium arc in a nitrogen environment

    E-Print Network [OSTI]

    Rosen, Johanna; Anders, Andre; Hultman, Lars; Schneider, Jochen M.

    2004-01-01

    of a pulsed cathodic arc plasma was investigated atof a growing film in arc plasma deposition. In the presencea titanium cathodic arc plasma at varying nitrogen pressure,

  19. The evolution of ion charge states in cathodic vacuum arc plasmas: a review

    E-Print Network [OSTI]

    Anders, Andre

    2013-01-01

    in metal vapor vacuum arc plasmas and ion sources," Plasmathe separation of cathodic arc plasma and macroparticles incharge states in vacuum arc plasmas in a magnetic field,"

  20. Ultrathin diamond-like carbon films deposited by filtered carbon vacuum arcs

    E-Print Network [OSTI]

    Anders, Andre; Fong, Walton; Kulkarni, Ashok; Ryan, Francis W.; Bhatia, C. Singh

    2001-01-01

    Ion velocities in vacuum arc plasmas, J. Appl. Phys. , vol.Brown, Transport of vacuum arc plasma through straight anda filtered cathodic arc, Plasma Sources Sci. Technol. , pp.

  1. Material and time dependence of the voltage noise generated by cathodic vacuum arcs

    E-Print Network [OSTI]

    Rosen, Johanna; Anders, Andre

    2005-01-01

    associated with plasma production and arc impedance, it wasbecause it is known that arc plasma parameters have almost Applications of Vacuum-Arc-Produced Plasma, Ion and Electron

  2. Ion source with improved primary arc collimation

    DOE Patents [OSTI]

    Dagenhart, W.K.

    1983-12-16

    An improved negative ion source is provided in which a self-biasing, molybdenum collimator is used to define the primary electron stream arc discharge from a filament operated at a negative potential. The collimator is located between the anode and the filament. It is electrically connected to the anode by means of an appropriate size resistor such that the collimator is biased at essentially the filament voltage during operation. Initially, the full arc voltage appears across the filament to collimator until the arc discharge strikes. Then the collimator biases itself to essentially filament potential due to current flow through the resistor thus defining the primary electron stream without intercepting any appreciable arc power. The collimator aperture is slightly smaller than the anode aperture to shield the anode from the arc power which, in the past, has caused overheating and erosion of the anode collimator during extended time pulsed-beam operation of the source. With the self-biasing collimator of this invention, the ion source may be operated from short pulse periods to steady-state without destroying the anode.

  3. Mechanical discontinuities monitoring at Merapi volcano using kinematic GPS

    E-Print Network [OSTI]

    Beauducel, Franois

    Mechanical discontinuities monitoring at Merapi volcano using kinematic GPS F. Beauducel a,c,*, M to precisely locate major mechanical discontinuities within the edifice. Precisely locating to evaluate potential volumes of falling material. The kinematic GPS method offers a way to partially solve

  4. LATE QUATERNARY GLACIATION OF THE ERCIYES VOLCANO, CENTRAL TURKEY

    E-Print Network [OSTI]

    Zreda, Marek

    LATE QUATERNARY GLACIATION OF THE ERCIYES VOLCANO, CENTRAL TURKEY SARIKAYA, M. Akif1, INER, Attila, Turkey, aciner@hun.edu.tr, (2) Hydrology and Water Resources, Univ of Arizona, Tucson, AZ 85721 Mount Erciyes (3917 m), highest stratovolcano of Central Turkey, is located in the northeastern part

  5. The sun, volcanoes, computers and the foundations of

    E-Print Network [OSTI]

    Phipps, Steven J.

    The sun, volcanoes, computers and the foundations of palaeoclimate Steven J. Phipps Climate Change374, 2000 #12;Climatic Change, 45, 361374, 2000 #12;Extreme weather events of 535536 CE The sun was dark the Syrian During this year [536 CE] a most dread portent took place. For the sun gave forth its light

  6. ARTICLE IN PRESS Volcano geodesy and magma dynamics in Iceland

    E-Print Network [OSTI]

    Pedersen, Rikke

    ARTICLE IN PRESS Volcano geodesy and magma dynamics in Iceland Erik Sturkell a,*, Pall Einarsson b-van Dalfsen d , Alan T. Linde e , Selwyn I. Sacks e , Ragnar Stefansson a a Icelandic Meteorological Office, Reykjavik, Bustaavegur 9, 150 Reykjavik, Iceland b Institute of Earth Sciences, University of Iceland

  7. REDUCING THE RISK FROM VOLCANO HAZARDS UNITED STATES GEOLOGICAL SURVEY

    E-Print Network [OSTI]

    systems, and cause jet engines to fail. USGS and other scientists with the Alaska Volcano Observatory eruptions. As the crew of KLM Flight 867 struggled to restart the plane's engines, "smoke" and a strong odor Mountains(7,000to11,000feethigh).Allfour engines had flamed out when the aircraft in- advertently entered

  8. Influence of a transverse magnetic field on arc root movements in a dc plasma torch: Diamagnetic effect of arc column

    SciTech Connect (OSTI)

    Kim, Keun Su

    2009-03-23

    The effect of a transverse magnetic field on the anodic arc root movement inside a dc plasma torch has been investigated. The arc voltage fluctuation, which represents the degree of the arc instability, was reduced to 28.6% of the original value and the high frequency components in the voltage signal also decreased in their magnitudes. The inherent arc instability in a dc thermal plasma torch seems to be suppressed by a diamagnetic effect of the arc column. Furthermore, the measured voltage wave forms indicated that the arc root attachment mode would be controllable by a transverse magnetic field.

  9. Ion source based on the cathodic arc

    DOE Patents [OSTI]

    Sanders, D.M.; Falabella, S.

    1994-02-01

    A cylindrically symmetric arc source to produce a ring of ions which leave the surface of the arc target radially and are reflected by electrostatic fields present in the source to a point of use, such as a part to be coated, is described. An array of electrically isolated rings positioned in the source serves the dual purpose of minimizing bouncing of macroparticles and providing electrical insulation to maximize the electric field gradients within the source. The source also includes a series of baffles which function as a filtering or trapping mechanism for any macroparticles. 3 figures.

  10. Volcano-tectonic modelling of magma chambers, ring-faults, unrest, and eruptions in the Tianchi Volcano, China

    E-Print Network [OSTI]

    Sheldon, Nathan D.

    this range to AD938-946), produced between 96 and 172 km3 of deposits, or around 30 km3 of dense magma, and is one of the largest eruptions on Earth during the past 1100 years. A 5-km-diameter collapse caldera, indicating that the shallow magma chamber and/or an associated geothermal system beneath the volcano

  11. Connecting ARC/INFO and SNACTor Project Report

    E-Print Network [OSTI]

    California at Santa Barbara, University of

    Connecting ARC/INFO and SNACTor Project Report June 1991 Stuart C. Shapiro, Hans Chalupsky;Connecting ARC/INFO* and SNACTor --- Project Report1 Stuart C. Shapiro2 , Hans Chalupsky2 and Hsueh

  12. A study of vacuum arc ion velocities using a linear set of probes

    E-Print Network [OSTI]

    Hohenbild, Stefan

    2008-01-01

    method; aluminum plasma; arc current constant at 200 A.velocity in vacuum arc plasmas by arc current perturbationin the vicinity of the arc plasma source. submitted to J.

  13. Ion flux from vacuum arc cathode spots in the absence and presence of a magnetic field

    E-Print Network [OSTI]

    Anders, Andre; Yushkov, George Yu.

    2001-01-01

    velocity in vacuum arc plasmas by arc current perturbation,field increases the plasma impedance, arc burning voltage,is well-known that the vacuum arc plasma is produced at non-

  14. Modeling rf breakdown arcs II: plasma / materials interactions

    E-Print Network [OSTI]

    Insepov, Zeke; Proslier, Thomas; Mahalingam, Sudhakar; Veitzer, S

    2010-01-01

    Continuing the description of rf vacuum arcs from an earlier paper, we describe some aspects of the interaction of vacuum arcs that involve the surface. This paper describes aspects of plasma materials interactions that affect the arc and models measurement of the surface field using the Tonks-Frenkel and the spinodal electrohydrodynamic instabilities, a realistic model for the generation and evaluation of high field enhancements, unipolar arcs, creep and other effects.

  15. Costing of Joining Methods -Arc Welding Costs

    E-Print Network [OSTI]

    Colton, Jonathan S.

    Costing of Joining Methods - Arc Welding Costs ver. 1 ME 6222: Manufacturing Processes and Systems.S. Colton GIT 2009 5 #12;LaborLabor Di t ti f ldi Direct time of welding time to produce a length of weld labor rate multiplication gives labor cost per length Set-up time, etc. Personal time

  16. Pairing, pseudogap and Fermi arcs in cuprates

    SciTech Connect (OSTI)

    Kaminski, Adam; Gu, Genda; Kondo, Takeshi; Takeuchi, Tsunehiro

    2014-04-29

    We use Angle Resolved Photoemission Spectroscopy (ARPES) to study the relationship between the pseudogap, pairing and Fermi arcs in cuprates. High quality data measured over a wide range of dopings reveals a consistent picture of Fermiology and pairing in these materials. The pseudogap is due to an ordered state that competes with superconductivity rather than preformed pairs. Pairing does occur below Tpair ~ 150K and significantly above Tc, but well below T* and the doping dependence of this temperature scale is distinct from that of the pseudogap. The d-wave gap is present below Tpair, and its interplay with strong scattering creates artificial Fermi arcs for Tc < T < Tpair. However, above Tpair, the pseudogap exists only at the antipodal region. This leads to presence of real, gapless Fermi arcs close to the node. The length of these arcs remains constant up to T*, where the full Fermi surface is recovered. We demonstrate that these findings resolve a number of seemingly contradictory scenarios.

  17. Remote electrical arc suppression by laser filamentation

    E-Print Network [OSTI]

    Schubert, Elise; Kasparian, Jrme; Wolf, Jean-Pierre

    2015-01-01

    We investigate the interaction of narrow plasma channels formed in the filamentation of ultrashort laser pulses, with a DC high voltage. The laser filaments prevent electrical arcs by triggering corona that neutralize the high-voltage electrodes. This phenomenon, due to the electric field modulation and free electron release around the filament, opens new prospects to lightning and over-voltage mitigation.

  18. Pairing, pseudogap and Fermi arcs in cuprates

    SciTech Connect (OSTI)

    Kaminski, Adam [Iowa State Univ., Ames, IA (United States); Gu, Genda [Brookhaven National Lab. (BNL), Upton, NY (United States); Kondo, Takeshi [The Univ. of Tokyo, Chiba (Japan); Takeuchi, Tsunehiro [Nagoya Univ., Nagoya (Japan)

    2014-10-31

    We use Angle Resolved Photoemission Spectroscopy (ARPES) to study the relationship between the pseudogap, pairing and Fermi arcs in cuprates. High quality data measured over a wide range of dopings reveals a consistent picture of Fermiology and pairing in these materials. The pseudogap is due to an ordered state that competes with superconductivity rather than preformed pairs. Pairing does occur below Tpair ~ 150K and significantly above Tc, but well below T* and the doping dependence of this temperature scale is distinct from that of the pseudogap. The d-wave gap is present below Tpair, and its interplay with strong scattering creates artificial Fermi arcs for Tc < T < Tpair. However, above Tpair, the pseudogap exists only at the antipodal region. This leads to presence of real, gapless Fermi arcs close to the node. The length of these arcs remains constant up to T*, where the full Fermi surface is recovered. We demonstrate that these findings resolve a number of seemingly contradictory scenarios.

  19. Exploring the Deep... Using ArcMap

    E-Print Network [OSTI]

    Wright, Dawn Jeannine

    started Exploring the Ocean Environment Introduction #12;The ArcMap User Interface Table of Contents off the layers above that layer in the Table of Contents. Table of Contents A list of data frames of the current map file. Coordinates Displays the coordinates, in the currently-selected units, of the cursor

  20. Energy Savings in Electric Arc Furnace Melting

    E-Print Network [OSTI]

    Lubbeck, W.

    1982-01-01

    Arc furnace melting which at one time was almost exclusively used to produce alloy steel and steel castings is now widely accepted in the industry as an efficient process to produce all types of steel and iron. Presently, about 28% of steel...

  1. Pairing, pseudogap and Fermi arcs in cuprates

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

    Kaminski, Adam; Kondo, Takeshi; Takeuchi, Tsunehiro; Gu, Genda

    2014-04-29

    We use Angle Resolved Photoemission Spectroscopy (ARPES) to study the relationship between the pseudogap, pairing and Fermi arcs in cuprates. High quality data measured over a wide range of dopings reveals a consistent picture of Fermiology and pairing in these materials. The pseudogap is due to an ordered state that competes with superconductivity rather than preformed pairs. Pairing does occur below Tpair ~ 150K and significantly above Tc, but well below T* and the doping dependence of this temperature scale is distinct from that of the pseudogap. The d-wave gap is present below Tpair, and its interplay with strong scatteringmorecreates artificial Fermi arcs for Tc ? T ? Tpair. However, above Tpair, the pseudogap exists only at the antipodal region. This leads to presence of real, gapless Fermi arcs close to the node. The length of these arcs remains constant up to T*, where the full Fermi surface is recovered. As a result, we demonstrate that these findings resolve a number of seemingly contradictory scenarios.less

  2. Theory of the arc discharge in air blast breakers

    SciTech Connect (OSTI)

    Vogel, H.F.

    1980-08-01

    The complete set of equations obtaining in the arc's length element are given. The arc length is determined when the external circuit equations are closed by an expression for the arc inductance as a function of the radius and length, in addition to our relationships for the radius and voltage gradients.

  3. Dynamic Behaviors of Plasma Reflection during Keyhole Arc Welding

    E-Print Network [OSTI]

    Zhang, YuMing

    Dynamic Behaviors of Plasma Reflection during Keyhole Arc Welding YuMing Zhang and Yi Ma Welding Engineering College of Engineering University of Kentucky #12;Keyhole Double-Sided Arc Welding Work PAW Torch: in any existing arc welding process? No ! Why Not in Keyhole PAW? No current through the keyhole ! Plasma

  4. Driven Motion and Instability of an Atmospheric Pressure Arc

    E-Print Network [OSTI]

    of equilibrium and stability of such arcs, an experimental arc furnace is constructed and operated in air. Applicability of the results of the thesis to an industrial steelmaking furnace is considered. iv #12; Dedicated am very thankful to Lane Roquemore for helping get the Arc Furnace o# the ground and for his

  5. PYROLYSIS OF METHANE IN A SUPERSONIC, ARC-HEATED FLOW

    E-Print Network [OSTI]

    Texas at Arlington, University of

    1 PYROLYSIS OF METHANE IN A SUPERSONIC, ARC-HEATED FLOW F.K. Lu,* C.M. Roseberry, J.M. Meyers and D arc pyrolysis of methane at supersonic conditions, representative of conditions in the reformer location of an aibreathing hypersonic vehicle. The rationale for arc pyrolysis is provided. Major

  6. INSTRUCTIONS FOR USING ARCVIEW ArcViewsoftwareisavailableintheUTSLab,

    E-Print Network [OSTI]

    Thompson, Michael

    SciencesBuilding,Room241and in Mills Library, Gateway Data/GIS Lab, Room 111A. Arc the ArcView GIS icon. If you are in the Map Collection or the Gateway Data/GIS Lab: Before starting copy of the data files.) Select Start. Select Programs. Select ArcView GIS. If your first screen does

  7. Aplicaciones de Arc GISAplicaciones de Arc GIS en Recursos de Aguaen Recursos de Agua

    E-Print Network [OSTI]

    Gilbes, Fernando

    Aplicaciones de Arc GISAplicaciones de Arc GIS en Recursos de Aguaen Recursos de Agua Alejandra 14: 440 personas/km2 vrs India y Japn 338vrs India y Japn 338 perper/km2./km2. El uso del agua se ha incrementado un 1.6% de 1970 aEl uso del agua se ha incrementado un 1.6% de 1970 a 1995 con 2

  8. Numerical investigation of the double-arcing phenomenon in a cutting arc torch

    SciTech Connect (OSTI)

    Mancinelli, B. R.; Minotti, F. O.; Kelly, H.; Prevosto, L.

    2014-07-14

    A numerical investigation of the double-arcing phenomenon in a cutting arc torch is reported. The dynamics of the double-arcing were simulated by using a two-dimensional model of the gas breakdown development in the space-charge layer contiguous to the nozzle of a cutting arc torch operated with oxygen. The kinetic scheme includes ionization of heavy particles by electron impact, electron attachment, electron detachment, electronion recombination, and ionion recombination. Complementary measurements during double-arcing phenomena were also conducted. A marked rise of the nozzle voltage was found. The numerical results showed that the dynamics of a cathode spot at the exit of the nozzle inner surface play a key role in the raising of the nozzle voltage, which in turn allows more electrons to return to the wall at the nozzle inlet. The return flow of electrons thus closes the current loop of the double-arcing. The increase in the (floating) nozzle voltage is due to the fact that the increased electron emission at the spot is mainly compensated by the displacement current (the ions do not play a relevant role due to its low-mobility) until that the stationary state is achieved and the electron return flow fully-compensates the electron emission at the spot. A fairly good agreement was found between the model and the experiment for a spot emission current growth rate of the order of 7??10{sup 4}?A/s.

  9. Magnetized Cascade Arc Source forMagnetized Cascade Arc Source for Ionization and Fuelling in TCSUIonization and Fuelling in TCSU

    E-Print Network [OSTI]

    Washington at Seattle, University of

    , the arc source can also be run during FRC sustainment to provide steady state plasma fuelling. The deuterium plasma produced by the arc source is tied to the external axial magnetic field lines, providing and is used for initial breakdown and arc sustainment. Plasma densities of 1020 m-3 and electron temperatures

  10. Characteristic of a triple-cathode vacuum arc plasma source

    SciTech Connect (OSTI)

    Xiang, W.; Li, M.; Chen, L.

    2012-02-15

    In order to generate a better ion beam, a triple-cathode vacuum arc plasma source has been developed. Three plasma generators in the vacuum arc plasma source are equally located on a circle. Each generator initiated by means of a high-voltage breakdown between the cathode and the anode could be operated separately or simultaneously. The arc plasma expands from the cathode spot region in vacuum. In order to study the behaviors of expanding plasma plume generated in the vacuum arc plasma source, a Langmuir probe array is employed to measure the saturated ion current of the vacuum arc plasma source. The time-dependence profiles of the saturated current density of the triple vacuum arc plasma source operated separately and simultaneously are given. Furthermore, the plasma characteristic of this vacuum arc plasma source is also presented in the paper.

  11. Magmatichydrothermal evolution and devolatilization beneath Merapi volcano, Indonesia

    E-Print Network [OSTI]

    as a supercritical fluid and that it subsequently exsolved into a H2OClF-rich brine and CO2S-rich vapor. According C fluid, although the presence of H2S, SO2 and CO2 may cause the supercritical fluid to unmix inclusions Volcanic gases Vapor-brine exsolution CO2H2O barometry At Merapi volcano, Indonesia, explosive

  12. Summary of Pu?u ?O?o - Kupaianaha Eruption, Kilauea Volcano...

    Open Energy Info (EERE)

    Survey, 2012 DOI Not Provided Check for DOI availability: http:crossref.org Online Internet link for Summary of Puu Oo - Kupaianaha Eruption, Kilauea Volcano, Hawaii...

  13. Electrical Safety and Arc Flash Protections

    SciTech Connect (OSTI)

    R. Camp

    2008-03-04

    Over the past four years, the Electrical Safety Program at PPPL has evolved in addressing changing regulatory requirements and lessons learned from accident events, particularly in regards to arc flash hazards and implementing NFPA 70E requirements. This presentation will discuss PPPL's approaches to the areas of electrical hazards evaluation, both shock and arc flash; engineered solutions for hazards mitigation such as remote racking of medium voltage breakers, operational changes for hazards avoidance, targeted personnel training and hazard appropriate personal protective equipment. Practical solutions for nominal voltage identification and zero voltage checks for lockout/tagout will also be covered. Finally, we will review the value of a comprehensive electrical drawing program, employee attitudes expressed as a personal safety work ethic, integrated safety management, and sustained management support for continuous safety improvement.

  14. Filtered cathodic arc deposition apparatus and method

    DOE Patents [OSTI]

    Krauss, Alan R. (24461 W. Blvd. De John, Naperville, IL 60564)

    1999-01-01

    A filtered cathodic arc deposition method and apparatus for the production of highly dense, wear resistant coatings which are free from macro particles. The filtered cathodic arc deposition apparatus includes a cross shaped vacuum chamber which houses a cathode target having an evaporable surface comprised of the coating material, means for generating a stream of plasma, means for generating a transverse magnetic field, and a macro particle deflector. The transverse magnetic field bends the generated stream of plasma in the direction of a substrate. Macro particles are effectively filtered from the stream of plasma by traveling, unaffected by the transverse magnetic field, along the initial path of the plasma stream to a macro particle deflector. The macro particle deflector has a preformed surface which deflects macro particles away from the substrate.

  15. Cathodic Vacuum Arc Plasma of Thallium

    SciTech Connect (OSTI)

    Yushkov, Georgy Yu.; Anders, Andre

    2006-10-02

    Thallium arc plasma was investigated in a vacuum arc ionsource. As expected from previous consideration of cathode materials inthe Periodic Table of the Elements, thallium plasma shows lead-likebehavior. Its mean ion charge state exceeds 2.0 immediately after arctriggering, reaches the predicted 1.60 and 1.45 after about 100 microsecand 150 microsec, respectively. The most likely ion velocity is initially8000 m/s and decays to 6500 m/s and 6200 m/s after 100 microsec and 150microsec, respectively. Both ion charge states and ion velocities decayfurther towards steady state values, which are not reached within the 300microsec pulses used here. It is argued that the exceptionally high vaporpressure and charge exchange reactions are associated with theestablishment of steady state ion values.

  16. Combined U-Th/He and 40Ar/39Ar geochronology of post-shield lavas from the Mauna Kea and Kohala volcanoes, Hawaii

    E-Print Network [OSTI]

    Aciego, S.M.

    2010-01-01

    from Hualalai Volcano, Hawaii. Geochemistry Geophysicsfrom Kilauea Volcano, Hawaii. Science 161(3846), 1132-1135.Lake Waiau, Mauna Kea, Hawaii. Pacific Science Farley K.

  17. Arc Casting Intermetallic Alloy (Materials Preparation Center)

    SciTech Connect (OSTI)

    2010-01-01

    Arc casting of intermetallic (La-Ni-Sn) AB5 alloy used for metal hydride hydrogen storage. Upon solidification the Sn is partially rejected and increases in concentration in the remaining liquid. Upon completing solidification there is a great deal of internal stress in the ingot. As the ingot cools further the stress is relieved. This material was cast at the Ames Laboratorys Materials Preparation Center http://www.mpc.ameslab.gov

  18. Volumetric modulated arc radiotherapy for esophageal cancer

    SciTech Connect (OSTI)

    Vivekanandan, Nagarajan, E-mail: viveknaren@hotmail.com [Department of Medical Physics, Cancer Institute, Chennai (India); Sriram, Padmanaban; Syam Kumar, S.A.; Bhuvaneswari, Narayanan; Saranya, Kamalakannan [Department of Medical Physics, Cancer Institute, Chennai (India)

    2012-04-01

    A treatment planning study was performed to evaluate the performance of volumetric arc modulation with RapidArc (RA) against 3D conformal radiation therapy (3D-CRT) and conventional intensity-modulated radiation therapy (IMRT) techniques for esophageal cancer. Computed tomgraphy scans of 10 patients were included in the study. 3D-CRT, 4-field IMRT, and single-arc and double-arc RA plans were generated with the aim to spare organs at risk (OAR) and healthy tissue while enforcing highly conformal target coverage. The planning objective was to deliver 54 Gy to the planning target volume (PTV) in 30 fractions. Plans were evaluated based on target conformity and dose-volume histograms of organs at risk (lung, spinal cord, and heart). The monitor unit (MU) and treatment delivery time were also evaluated to measure the treatment efficiency. The IMRT plan improves target conformity and spares OAR when compared with 3D-CRT. Target conformity improved with RA plans compared with IMRT. The mean lung dose was similar in all techniques. However, RA plans showed a reduction in the volume of the lung irradiated at V{sub 20Gy} and V{sub 30Gy} dose levels (range, 4.62-17.98%) compared with IMRT plans. The mean dose and D{sub 35%} of heart for the RA plans were better than the IMRT by 0.5-5.8%. Mean V{sub 10Gy} and integral dose to healthy tissue were almost similar in all techniques. But RA plans resulted in a reduced low-level dose bath (15-20 Gy) in the range of 14-16% compared with IMRT plans. The average MU needed to deliver the prescribed dose by RA technique was reduced by 20-25% compared with IMRT technique. The preliminary study on RA for esophageal cancers showed improvements in sparing OAR and healthy tissue with reduced beam-on time, whereas only double-arc RA offered improved target coverage compared with IMRT and 3D-CRT plans.

  19. Tephra stratigraphy and geochemistry from three Icelandic lake cores: a new method for determining source volcano of tepra layers

    E-Print Network [OSTI]

    Jagan, Anna

    2010-01-01

    At present there is no consistent method for the identification of source volcanoes for a tephra layer found in a stratigraphy. This has led to several studies misidentifying source volcanoes. Geochemical analysis of the ...

  20. Validation of Innovative Exploration Technologies for Newberry Volcano: Raw data used to prepare the Gravity Report by Zonge 2012

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Jaffe, Todd

    2012-01-01

    Validation of Innovative Exploration Technologies for Newberry Volcano: Raw data used to prepare the Gravity Report by Zonge 2012

  1. Validation of Innovative Exploration Technologies for Newberry Volcano: Seismic data - raw taken by Apex Hipoint for 1st test 2012

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Jaffe, Todd

    2012-01-01

    Validation of Innovative Exploration Technologies for Newberry Volcano: Seismic data - raw taken by Apex Hipoint for 1st test 2012

  2. Validation of Innovative Exploration Technologies for Newberry Volcano: Seismic data - raw taken by Apex Hipoint for 1st test 2012

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Jaffe, Todd

    Validation of Innovative Exploration Technologies for Newberry Volcano: Seismic data - raw taken by Apex Hipoint for 1st test 2012

  3. Validation of Innovative Exploration Technologies for Newberry Volcano: Raw data used to prepare the Gravity Report by Zonge 2012

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Jaffe, Todd

    Validation of Innovative Exploration Technologies for Newberry Volcano: Raw data used to prepare the Gravity Report by Zonge 2012

  4. Preliminary analysis of volcanoseismic signals recorded at the Tatun Volcano Group, northern Taiwan

    E-Print Network [OSTI]

    Lin, Cheng-Horng

    ] The Tatun Volcano Group lies at the northern tip of Taiwan only 15 km north of the capital Taipei. A seismic in 2003 in order to monitor the seismic activity of the area. It recorded a variety of events including that the Tatun volcanoes are extinct and prompt for a thorough assessment of the volcanic hazard for this area

  5. Observing Iceland's Eyjafjallajkull 2010 eruptions with the autonomous NASA Volcano Sensor Web

    E-Print Network [OSTI]

    Wright, Robert

    Observing Iceland's Eyjafjallajkull 2010 eruptions with the autonomous NASA Volcano Sensor Web, the Hyperion hyperspectral imager and Advanced Land Imager (ALI) on NASA's Earth Observing 1 (EO-1) spacecraft by using the autonomously operating NASA Volcano Sensor Web (VSW). The VSW incorporates notifications

  6. SO2 emissions to the atmosphere from active volcanoes in Guatemala and El Salvador, 19992002

    E-Print Network [OSTI]

    Rose, William I.

    SO2 emissions to the atmosphere from active volcanoes in Guatemala and El Salvador, 1999 INSIVUMEH, 7a Avenida 14-57 Zona 13, Ciudad de Guatemala, Guatemala, Central America c Servicio Nacional de-based and aircraft correlation spectrometer (COSPEC) measurements at the principal active volcanoes in Guatemala

  7. Seismic characterization of the fall 2007 eruptive sequence at Bezymianny Volcano, Russia

    E-Print Network [OSTI]

    West, Michael

    Seismic characterization of the fall 2007 eruptive sequence at Bezymianny Volcano, Russia Weston of Geophysical Services, Russian Academy of Sciences, Petropavlosk, Russia d Cascade Volcano Observatory, United classification scheme. Low-frequency tremor, interpreted as gas escape, and low-frequency earthquakes

  8. Hawaii Volcanoes National Park Traffic and Parking: Current Issues, Future Solutions Hawaii Volcanoes National Park (HAVO) is experiencing increased visitor use and congestion/

    E-Print Network [OSTI]

    Prevedouros, Panos D.

    Hawaii Volcanoes National Park Traffic and Parking: Current Issues, Future Solutions Hawaii, and unsafe practices. This project will record and analyze these issues. NPS staff and University of Hawaii

  9. Theory of Parabolic Arcs in Interstellar Scintillation Spectra

    E-Print Network [OSTI]

    James M. Cordes; Barney J. Rickett; Daniel R. Stinebring; William A. Coles

    2004-07-03

    Our theory relates the secondary spectrum, the 2D power spectrum of the radio dynamic spectrum, to the scattered pulsar image in a thin scattering screen geometry. Recently discovered parabolic arcs in secondary spectra are generic features for media that scatter radiation at angles much larger than the rms scattering angle. Each point in the secondary spectrum maps particular values of differential arrival-time delay and fringe rate (or differential Doppler frequency) between pairs of components in the scattered image. Arcs correspond to a parabolic relation between these quantities through their common dependence on the angle of arrival of scattered components. Arcs appear even without consideration of the dispersive nature of the plasma. Arcs are more prominent in media with negligible inner scale and with shallow wavenumber spectra, such as the Kolmogorov spectrum, and when the scattered image is elongated along the velocity direction. The arc phenomenon can be used, therefore, to constrain the inner scale and the anisotropy of scattering irregularities for directions to nearby pulsars. Arcs are truncated by finite source size and thus provide sub micro arc sec resolution for probing emission regions in pulsars and compact active galactic nuclei. Multiple arcs sometimes seen signify two or more discrete scattering screens along the propagation path, and small arclets oriented oppositely to the main arc persisting for long durations indicate the occurrence of long-term multiple images from the scattering screen.

  10. ArcSafe with Pulsed Arrested Spark Discharge

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

    Form ArcSafe with Pulsed Arrested Spark Discharge &24; The world's only advanced electrical wiring diagnostic capable of detecting insulation defects in complex wiring systems...

  11. Arc-Fault Detector Algorithm Evaluation Method Utilizing Prerecorded...

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

    Electrical Code Article 690.11 requires photovoltaic systems on or penetrating a building to include a DC arc-fault protection device. In order to satisfy this...

  12. A Dynamic Traveling Salesman Problem with Stochastic Arc Costs

    E-Print Network [OSTI]

    Alejandro Toriello

    2012-08-31

    Aug 31, 2012 ... Abstract: We propose a dynamic traveling salesman problem (TSP) with stochastic arc costs motivated by applications, such as dynamic...

  13. PV Arc Fault Detector Challenges Due to Module Frequency Response...

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

    This poster does not contain any proprietary or confidential information. Introduction PV system arc faults have led to a number of rooftop fires which have caused significant...

  14. High Charge State Ions Extracted from Metal Plasmas in the Transition Regime from Vacuum Spark to High Current Vacuum Arc

    E-Print Network [OSTI]

    Anders, Georgy, Yu. Yushkov, Andre

    2008-01-01

    of expanding vacuum arc plasmas, IEEE Trans. Plasma Sci. ,in high current vacuum arc plasma in a magnetic field, IEEEdistributions of vacuum arc plasmas: The origin of species,

  15. Puzzling differences in bismuth and lead plasmas: evidence for the significant role of neutrals in cathodic vacuum arcs

    E-Print Network [OSTI]

    Anders, Andre; Yushkov, Georgy Yu.

    2007-01-01

    for Pb and Bi cathodic arc plasmas revealed unexpectedCathodic vacuum arc plasmas are generally considered to beand (iv) the condensing arc plasma itself, because non-

  16. Production of neutrals and their and effects on the ion charge states in cathodic vacuum arc plasmas

    E-Print Network [OSTI]

    Anders, Andre; Oks, Efim M.; Yushkov, Georgy Yu.

    2007-01-01

    states in cathodic vacuum arc plasmas Andr Anders a , EfimRussia Abstract Cathodic arc plasmas are considered fullybeen known that cathodic arc plasmas go through an initial

  17. Influence of argon and oxygen on charge-state-resolved ion energy distributions of filtered aluminum arcs

    E-Print Network [OSTI]

    Rosen, Johanna; Anders, Andre; Mraz, Stanislav; Atiser, Adil; Schneider, Jochen M.

    2006-01-01

    in filtered aluminum vacuum arc plasmas were measured andI. INTRODUCTION Vacuum arc plasma is well known to be highlymeasured for vacuum arc plasmas. Aluminum plasma, for

  18. Mo-containing tetrahedral amorphous carbon deposited by dual filtered cathodic vacuum arc with selective pulsed bias voltage

    E-Print Network [OSTI]

    Pasaja, Nitisak; Sansongsiri, Sakon; Intasiri, Sawate; Vilaithong, Thiraphat; Anders, Andre

    2007-01-01

    filtered cathodic vacuum arc plasma sources with selectivedual filtered cathodic vacuum arc plasma sources operated inrepetitively pulsed vacuum arc plasma sources operating in

  19. Effect of ion mass and charge state on transport of vacuum ARC plasmas through a biased magnetic filter

    E-Print Network [OSTI]

    Byon, Eungsun; Kim, Jong-Kuk; Kwon, Sik-Chol; Anders, Andre

    2003-01-01

    G. Brown, "Transport of vacuum arc plasmas through magneticto rid cathodic arc plasma of macro- and nanoparticles: afrom cathodic arc plasmas," Surf. Coat. Technol. , vol. 133-

  20. Mo-containing tetrahedral amorphous carbon deposited by dual filtered cathodic vacuum arc with selective pulsed bias voltage

    E-Print Network [OSTI]

    Pasaja, Nitisak; Sansongsiri, Sakon; Anders, Andre; Vilaithong, Thiraphat; Intasiri, Sawate

    2006-01-01

    filtered cathodic vacuum arc plasma sources with selectiverepetitively pulsed vacuum arc plasma sources operating inthe pulse length from each arc plasma source. They concluded

  1. Electrical properties of a-C:Mo films produced by dual-cathode filtered cathodic arc plasma deposition

    E-Print Network [OSTI]

    Sansongsiri, Sakon

    2008-01-01

    cathode filtered cathodic arc plasma system. Fig. 2. Filmfiltered cathodic arc plasma deposition Sakon Sansongsiri a,filtered cathodic arc plasma deposition Sakon Sansongsiri a,

  2. Time-dependence ion charge state distributions of vacuum arcs: An interpretation involving atoms and charge exchange collisions

    E-Print Network [OSTI]

    Anders, Andre

    2004-01-01

    functions of vacuum arc plasmas," J. Appl. Phys. , vol. 93,distributions of vacuum arc plasmas: The origin of species,"energetic condensation of cathodic arc plasma. More detailed

  3. Method for controlling gas metal arc welding

    DOE Patents [OSTI]

    Smartt, Herschel B. (Idaho Falls, ID); Einerson, Carolyn J. (Idaho Falls, ID); Watkins, Arthur D. (Idaho Falls, ID)

    1989-01-01

    The heat input and mass input in a Gas Metal Arc welding process are controlled by a method that comprises calculating appropriate values for weld speed, filler wire feed rate and an expected value for the welding current by algorithmic function means, applying such values for weld speed and filler wire feed rate to the welding process, measuring the welding current, comparing the measured current to the calculated current, using said comparison to calculate corrections for the weld speed and filler wire feed rate, and applying corrections.

  4. Method for controlling gas metal arc welding

    DOE Patents [OSTI]

    Smartt, H.B.; Einerson, C.J.; Watkins, A.D.

    1987-08-10

    The heat input and mass input in a Gas Metal Arc welding process are controlled by a method that comprises calculating appropriate values for weld speed, filler wire feed rate and an expected value for the welding current by algorithmic function means, applying such values for weld speed and filler wire feed rate to the welding process, measuring the welding current, comparing the measured current to the calculated current, using said comparison to calculate corrections for the weld speed and filler wire feed rate, and applying corrections. 3 figs., 1 tab.

  5. Entropy in an Arc Plasma Source

    SciTech Connect (OSTI)

    Kaminska, A.; Dudeck, M

    2008-03-19

    The entropy properties in a D.C. argon arc plasma source are studied. The local thermodynamical entropy relations are established for a set of uniform sub-systems (Ar, Ar{sup +}, e) in order to deduce the entropy balance equation in presence of dissipative effects and in the case of a thermal non equilibrium. Phenomenological linear laws are deduced in near equilibrium situation. The flow parameters inside the plasma source are calculated by a Navier-Stokes fluid description taking into account a thermal local non equilibrium. The entropy function is calculated in the plasma source using the values of the local variables obtained from the numerical code.

  6. ScanArc ASA | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoop Inc Jump to:Newberg,EnergyEastCarbonOpen EnergyPonsa,Sasol ChevronSavannahScanArc

  7. AdaptiveARC | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoop IncIowaWisconsin: Energy Resources Jump to: navigation,Pennsylvania:AdaptiveARC

  8. Measurements of the Ion Species of Cathodic Arc Plasma in an Axial Magnetic Field

    E-Print Network [OSTI]

    Oks, Efim

    2011-01-01

    distributions of a vacuum arc plasma," Rev. Sci. Instrum. ,by filtered cathodic arc plasma," physica status solidi (a),in high current vacuum arc plasma in a magnetic field," IEEE

  9. A Summary of Recent Experimental Research on Ion Energy and Charge States of Pulsed Vacuum Arcs

    E-Print Network [OSTI]

    Oks, Efim M.

    2008-01-01

    Ion velocities in vacuum arc plasmas, J. Appl. Phys. , 2000,Anders, Cathodic Vacuum Arc Plasma of Thallium, IEEE Trans.in ca- thodic vacuum arc plasmas, J. Appl. Phys, 2007, vol.

  10. Ultrathin ta-C films on heads depositied by twist-filtered cathodic arc carbon plasmas

    E-Print Network [OSTI]

    Anders, Andre; Ryan, Francis W.

    2000-01-01

    Ion velocities in vacuum arc plasmas. submitted to J. Appl.to rid cathodic arc plasma of macro- and nanoparticles: aBrown, Transport of vacuum arc plasma through straight and

  11. Approaches to rid cathodic arc plasmas of macro- and nanoparticles: A review

    E-Print Network [OSTI]

    Anders, Andre

    2008-01-01

    Sablev, and R. I. Stupka, Plasma arc apparatus for applyingMagnetically filtered cathodic arc plasma apparatus, PatentRectangular vacuum-arc plasma source, Patent 5,480,527, Jan.

  12. Temporal Development of Ion Beam Mean Charge State in Pulsed Vacuum Arc Ion Sources

    E-Print Network [OSTI]

    Oks, Efim M.; Yushkov, Georgy Yu.; Anders, Andre

    2008-01-01

    temperature in the vacuum arc plasma and thus higher ioncharged ions in the vacuum arc plasma. The physical aspectsion charge states in vacuum arc plasma were subject of our

  13. Ion Species and Charge States of Vacuum Arc Plasma with Gas Feed and Longitudinal Magnetic Field

    E-Print Network [OSTI]

    Oks, Efim

    2010-01-01

    in cathodic vacuum arc plasmas, J. Appl. Phys. , vol. 102,models of the cathodic arc plasma and its interaction withand Charge States of Vacuum Arc Plasma with Gas Feed and

  14. ON THE CURRENT INTENSITY LIMIT OF A VACUUM ARC ION SOURCE

    E-Print Network [OSTI]

    Brown, I.G.

    2011-01-01

    for the metal vapor vacuum arc plasma discharge employed. inin the basic vacuum arc plasma source, and we have drawnThe vacuum arc is a prolific source of metal plasma, and the

  15. Investigation of non-hydrogenated DLC:Si prepared by cathodic arc

    E-Print Network [OSTI]

    Monteiro, Othon R.; Delplancke-Ogletree, Marie-Paule

    2002-01-01

    source filtered cathodic arc plasma, and the mechanical andpulse. Typical arc current in the plasma sources were 250 Athe cathodic arc source is 1.4 (the plasma stream consists

  16. ARC Centre of Excellence for Advanced Silicon Photovoltaics

    E-Print Network [OSTI]

    New South Wales, University of

    ARC Centre of Excellence for Advanced Silicon Photovoltaics and Photonics Annual Report 2005 ARC Centre of Excellence for Advanced Silicon Photovoltaics and Photonics Annual Report 2005 #12;Centre of Excellence for Advanced Silicon Photovoltaics and Photonics is a Centre of Excellence of The Australian

  17. Mechanism of carbon nanostructure synthesis in arc plasma

    SciTech Connect (OSTI)

    Keidar, M.; Shashurin, A.; Volotskova, O.; Raitses, Y.; Beilis, I. I.

    2010-05-15

    Plasma enhanced techniques are widely used for synthesis of carbon nanostructures. The primary focus of this paper is to summarize recent experimental and theoretical advances in understanding of single-wall carbon nanotube (SWNT) synthesis mechanism in arcs, and to describe methods of controlling arc plasma parameters. Fundamental issues related to synthesis of SWNTs, which is a relationship between plasma parameters and SWNT characteristics are considered. It is shown that characteristics of synthesized SWNTs can be altered by varying plasma parameters. Effects of electrical and magnetic fields applied during SWNT synthesis in arc plasma are explored. Magnetic field has a profound effect on the diameter, chirality, and length of a SWNT synthesized in the arc plasma. An average length of SWNT increases by a factor of 2 in discharge with magnetic field and an amount of long nanotubes with the length above 5 {mu}m also increases in comparison with that observed in the discharge without a magnetic field. In addition, synthesis of a few-layer graphene in a magnetic field presence is discovered. A coupled model of plasma-electrode phenomena in atmospheric-pressure anodic arc in helium is described. Calculations indicate that substantial fraction of the current at the cathode is conducted by ions (0.7-0.9 of the total current). It is shown that nonmonotonic behavior of the arc current-voltage characteristic can be reproduced taking into account the experimentally observed dependence of the arc radius on arc current.

  18. Research Article A Customization of the Arc Marine Data

    E-Print Network [OSTI]

    Wright, Dawn Jeannine

    Research Article A Customization of the Arc Marine Data Model to Support Whale Tracking via Mate Marine Mammal Institute, Oregon State University Dawn J Wright Department of Geosciences Oregon State University Tomas Follett Marine Mammal Institute, Oregon State University Abstract The Arc Marine

  19. Seismicity and structure of Akutan and Makushin Volcanoes, Alaska, using joint body and surface wave tomography

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

    Syracuse, E. M.; Maceira, M.; Zhang, H.; Thurber, C. H.

    2015-02-18

    Joint inversions of seismic data recover models that simultaneously fit multiple constraints while playing upon the strengths of each data type. Here, we jointly invert 14 years of local earthquake body wave arrival times from the Alaska Volcano Observatory catalog and Rayleigh wave dispersion curves based upon ambient noise measurements for local Vp, Vs, and hypocentral locations at Akutan and Makushin Volcanoes using a new joint inversion algorithm.The velocity structure and relocated seismicity of both volcanoes are significantly more complex than many other volcanoes studied using similar techniques. Seismicity is distributed among several areas beneath or beyond the flanks ofmoreboth volcanoes, illuminating a variety of volcanic and tectonic features. The velocity structures of the two volcanoes are exemplified by the presence of narrow high-Vp features in the near surface, indicating likely current or remnant pathways of magma to the surface. A single broad low-Vp region beneath each volcano is slightly offset from each summit and centered at approximately 7 km depth, indicating a potential magma chamber, where magma is stored over longer time periods. Differing recovery capabilities of the Vp and Vs datasets indicate that the results of these types of joint inversions must be interpreted carefully.less

  20. Seismicity and structure of Akutan and Makushin Volcanoes, Alaska, using joint body and surface wave tomography

    SciTech Connect (OSTI)

    Syracuse, E. M.; Maceira, M.; Zhang, H.; Thurber, C. H.

    2015-02-18

    Joint inversions of seismic data recover models that simultaneously fit multiple constraints while playing upon the strengths of each data type. Here, we jointly invert 14 years of local earthquake body wave arrival times from the Alaska Volcano Observatory catalog and Rayleigh wave dispersion curves based upon ambient noise measurements for local Vp, Vs, and hypocentral locations at Akutan and Makushin Volcanoes using a new joint inversion algorithm.The velocity structure and relocated seismicity of both volcanoes are significantly more complex than many other volcanoes studied using similar techniques. Seismicity is distributed among several areas beneath or beyond the flanks of both volcanoes, illuminating a variety of volcanic and tectonic features. The velocity structures of the two volcanoes are exemplified by the presence of narrow high-Vp features in the near surface, indicating likely current or remnant pathways of magma to the surface. A single broad low-Vp region beneath each volcano is slightly offset from each summit and centered at approximately 7 km depth, indicating a potential magma chamber, where magma is stored over longer time periods. Differing recovery capabilities of the Vp and Vs datasets indicate that the results of these types of joint inversions must be interpreted carefully.

  1. Applicability of moire deflection tomography for diagnosing arc plasmas

    SciTech Connect (OSTI)

    Chen Yunyun; Song Yang; He Anzhi; Li Zhenhua

    2009-01-20

    The argon arc plasma whose central temperature, 1.90x10{sup 4} K, is used as a practical example for an experiment to research the applicability of moire deflection tomography in arc plasma flow-field diagnosis. The experimental result indicates that moire deflection of the measured argon arc plasma is very small, even smaller than that of a common flame with the maximal temperature of nearly 1.80x10{sup 3} K. The refractive-index gradient in moire deflection tomography mainly contributes to the temperature gradient in essence when the probe wavelength and pressure are certain in plasma diagnosis. The applicable temperature ranges of moire deflection tomography in the argon arc plasma diagnosis are given with the probe wavelength 532 nm at 1 atm in certain measuring error requirements. In a word, the applicable temperature range of moire deflection tomography for arc plasma diagnosis is intimately related to the probe wavelength and the practical measuring requirements.

  2. Probing instabilities in arc plasma devices using binary gas mixtures

    SciTech Connect (OSTI)

    Ghorui, S.; Vysohlid, M.; Heberlein, J. V. R.; Pfender, E.

    2007-07-15

    This paper presents an experimental approach to identify the sources of instabilities in arc plasma devices. The phenomena of demixing in arcs have been utilized to explore the characteristics of different instabilities. Problems in explaining the observed behavior with our current understanding of the phenomena are discussed. Hydrogen is used as a secondary gas with argon as the primary plasma gas for this study. Results indicate that the observed behavior such as steady, takeover, and restrike modes of instabilities in arcs may essentially originate from the thin boundary layer over the anode wall primarily at the location of the anodic arc root. The bulk core flow apparently does not play any significant role in such instabilities. Arc currents rather than flow rates control the behavior of the instabilities in frequency space. Bifurcation of the system behavior and evidence for the existence of quadratic zones in flow space of binary gas mixtures separating steady and unsteady behavior are discussed.

  3. Measurement of total ion current from vacuum arc plasma sources

    SciTech Connect (OSTI)

    Oks, E.M.; Savkin, K.P.; Yushkov, G.Yu.; Nikolaev, A.G.; Anders, A.; Brown, I.G.

    2006-03-15

    The total ion current generated by a vacuum arc plasma source was measured. The discharge system investigated allowed ion collection from the arc plasma streaming through a hemispherical mesh anode with geometric transparency of 72%. A range of different cathode materials was investigated, and the arc current was varied over the range of 50-500 A. We find that the normalized ion current (I{sub ion}/I{sub arc}) depends on the cathode material, with values in the range from 5% to 19% and generally greater for elements of low cohesive energy. The application of a strong axial magnetic field in the cathode and arc region leads to increased normalized ion current, but only by virtue of enhanced ion charge states formed in a strong magnetic field.

  4. An Archean Oceanic Felsic Dyke Swarm In A Nascent Arc- The Hunter...

    Open Energy Info (EERE)

    indicate splitting of the arc. HMG and associated parts of the Abitibi greenstone belts bear a strong resemblance to modern rifted intraoceanic arcs of the western Pacific....

  5. Effect of underlayer on coalescence of silver islands grown by filtered cathodic arc deposition

    E-Print Network [OSTI]

    Byon, Eungsun; Anders, Andre

    2003-01-01

    1. A miniature pulsed cathodic arc plasma source 14) with ausing a pulsed cathodic arc plasma source with a Nb cathode.

  6. Type A Investigation of the Electrical Arc Injury at the Stanford...

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

    of the Electrical Arc Injury at the Stanford Linear Accelerator Complex on October 11, 2004 Type A Investigation of the Electrical Arc Injury at the Stanford Linear Accelerator...

  7. Alaska Open-file Report 144 Assessment of Thermal Springs Sites Aleutian Arc, Atka Island to Becherof Lake -- Preliminary Results and Evaluation

    SciTech Connect (OSTI)

    Motyka, R.J.; Moorman, M.A.; Liss, S.A.

    1981-12-01

    Twenty of more than 30 thermal spring areas reported to exist in the Aleutian arc extending from Atka Island to Becherof Lake were investigated during July and August, 1980. Thermal activity of three of these sites had diminished substantially or no longer existed. At least seven more sites where thermal-spring activity is probable or certain were not visited because of their remoteness or because of time constraints. The existence of several other reported thermal spring sites could not be verified; these sites are considered questionable. On the basis of geothermometry, subsurface reservoir temperatures in excess of 150 C are estimated for 10 of the thermal spring sites investigated. These sites all occur in or near regions of Recent volcanism. Five of the sites are characterized by fumaroles and steaming ground, indicating the presence of at least a shallow vapor-dominated zone. Two, the Makushin Valley and Glacier Valley thermal areas, occur on the flanks of active Mukushin Volcano located on Unalaska Island, and may be connected to a common source of heat. Gas geothermometry suggests that the reservoir feeding the Kliuchef thermal field, located on the flanks of Kliuchef volcano of northeast Atka Island, may be as high as 239 C.

  8. GIS Fundamentals Lesson 8: Buffering and Overlay Lesson 8: Buffering and Overlay in ArcGIS -ArcMAP

    E-Print Network [OSTI]

    Butler, Christopher J.

    GIS Fundamentals Lesson 8: Buffering and Overlay Lesson 8: Buffering and Overlay in ArcGIS - Arc. You should read chapter 9 in the GIS Fundamentals textbook. Data: All data are in \\L9 subdirectory within the bounds of an "in" polygon. 1 #12;GIS Fundamentals Lesson 8: Buffering and Overlay Surface DIST

  9. Lidar arc scan uncertainty reduction through scanning geometry optimization

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

    Wang, H.; Barthelmie, R. J.; Pryor, S. C.; Brown, G.

    2015-10-07

    Doppler lidars are frequently operated in a mode referred to as arc scans, wherein the lidar beam scans across a sector with a fixed elevation angle and the resulting measurements are used to derive an estimate of the n minute horizontal mean wind velocity (speed and direction). Previous studies have shown that the uncertainty in the measured wind speed originates from turbulent wind fluctuations and depends on the scan geometry (the arc span and the arc orientation). This paper is designed to provide guidance on optimal scan geometries for two key applications in the wind energy industry: wind turbine powermoreperformance analysis and annual energy production. We present a quantitative analysis of the retrieved wind speed uncertainty derived using a theoretical model with the assumption of isotropic and frozen turbulence, and observations from three sites that are onshore with flat terrain, onshore with complex terrain and offshore, respectively. The results from both the theoretical model and observations show that the uncertainty is scaled with the turbulence intensity such that the relative standard error on the 10 min mean wind speed is about 30 % of the turbulence intensity. The uncertainty in both retrieved wind speeds and derived wind energy production estimates can be reduced by aligning lidar beams with the dominant wind direction, increasing the arc span and lowering the number of beams per arc scan. Large arc spans should be used at sites with high turbulence intensity and/or large wind direction variation when arc scans are used for wind resource assessment.less

  10. mARC: Memory by Association and Reinforcement of Contexts

    E-Print Network [OSTI]

    Norbert Rimoux; Patrice Descourt

    2013-12-10

    This paper introduces the memory by Association and Reinforcement of Contexts (mARC). mARC is a novel data modeling technology rooted in the second quantization formulation of quantum mechanics. It is an all-purpose incremental and unsupervised data storage and retrieval system which can be applied to all types of signal or data, structured or unstructured, textual or not. mARC can be applied to a wide range of information clas-sification and retrieval problems like e-Discovery or contextual navigation. It can also for-mulated in the artificial life framework a.k.a Conway "Game Of Life" Theory. In contrast to Conway approach, the objects evolve in a massively multidimensional space. In order to start evaluating the potential of mARC we have built a mARC-based Internet search en-gine demonstrator with contextual functionality. We compare the behavior of the mARC demonstrator with Google search both in terms of performance and relevance. In the study we find that the mARC search engine demonstrator outperforms Google search by an order of magnitude in response time while providing more relevant results for some classes of queries.

  11. Anomalously High B-Values In The South Flank Of Kilauea Volcano...

    Open Energy Info (EERE)

    Anomalously High B-Values In The South Flank Of Kilauea Volcano, Hawaii- Evidence For The Distribution Of Magma Below Kilauea'S East Rift Zone Jump to: navigation, search OpenEI...

  12. Magmatic History Of The East Rift Zone Of Kilauea Volcano, Hawaii...

    Open Energy Info (EERE)

    Magmatic History Of The East Rift Zone Of Kilauea Volcano, Hawaii Based On Drill Core From SOH 1 Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article:...

  13. Swiss Geoscience Meeting, Lugano 2008 Simulation for a volcano monitoring network

    E-Print Network [OSTI]

    of up to 10 cm with the displacement of the vertical components typically in the range of 4 to 6 cm per types for volcano monitoring (e.g., seismicity, ground surface deformation, geothermal, gravity

  14. Eruptions of volcanoes in Iceland: Katla and Eyjafjallojokull P.M.E.Altham, University of Cambridge.

    E-Print Network [OSTI]

    Altham, Pat

    Eruptions of volcanoes in Iceland: Katla and Eyjafjalloj¨okull P.M.E.Altham, University to Iceland). Comment. Does the Duration of an eruption increase as the corresponding ReposeTime increases

  15. Structure Of The Lower East Rift Zone Of Kilauea Volcano, Hawaii...

    Open Energy Info (EERE)

    Structure Of The Lower East Rift Zone Of Kilauea Volcano, Hawaii, From Seismic And Gravity Data Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article:...

  16. A 3D Magnetic Structure Of Izu-Oshima Volcano And Their Changes...

    Open Energy Info (EERE)

    Volcano has a mean magnetization intensity ranging from 10.4 to 12.1 Am. The derived 3D magnetic structure shows low magnetization zones beneath the west-northwest of the...

  17. Acoustic stabilization of electric arc instabilities in nontransferred plasma torches

    SciTech Connect (OSTI)

    Rat, V.; Coudert, J. F.

    2010-03-08

    Electric arc instabilities in dc plasma torches lead to nonhomogeneous treatments of nanosized solid particles or liquids injected within thermal plasma jets. This paper shows that an additional acoustic resonator mounted on the cathode cavity allows reaching a significant damping of these instabilities, particularly the Helmholtz mode of arc oscillations. The acoustic resonator is coupled with the Helmholtz resonator of the plasma torch limiting the amplitude of arc voltage variations. It is also highlighted that this damping is dependent on friction effects in the acoustic resonator.

  18. Numerical simulation of carbon arc discharge for nanoparticle synthesis

    SciTech Connect (OSTI)

    Kundrapu, M.; Keidar, M.

    2012-07-15

    Arc discharge with catalyst-filled carbon anode in helium background was used for the synthesis of carbon nanoparticles. In this paper, we present the results of numerical simulation of carbon arc discharges with arc current varying from 10 A to 100 A in a background gas pressure of 68 kPa. Anode sublimation rate and current voltage characteristics are compared with experiments. Distribution of temperature and species density, which is important for the estimation of the growth of nanoparticles, is obtained. The probable location of nanoparticle growth region is identified based on the temperature range for the formation of catalyst clusters.

  19. A PRELIMINARY STUDY OF DOUBLE-SIDED ARC WELDING PROCESS IN SHIP STRUCTURE MANUFACTURING

    E-Print Network [OSTI]

    Zhang, YuMing

    A PRELIMINARY STUDY OF DOUBLE-SIDED ARC WELDING PROCESS IN SHIP STRUCTURE MANUFACTURING Yu Meeting, August 21-22, 2002 #12;Objective o Determine the feasibility of double-sided arc welding process in butt welding of DH-36 plates #12;Background: Process o Double-sided arc welding (DSAW): a novel arc

  20. FusionArc optimization: A hybrid volumetric modulated arc therapy (VMAT) and intensity modulated radiation therapy (IMRT) planning strategy

    SciTech Connect (OSTI)

    Matuszak, Martha M.; McShan, Daniel L.; Ten Haken, Randall K. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48109 (United States); Steers, Jennifer M. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48109 and Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States); Long, Troy; Edwin Romeijn, H. [Department of Industrial and Operations Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Fraass, Benedick A. [Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, California 90048 (United States)

    2013-07-15

    Purpose: To introduce a hybrid volumetric modulated arc therapy/intensity modulated radiation therapy (VMAT/IMRT) optimization strategy called FusionArc that combines the delivery efficiency of single-arc VMAT with the potentially desirable intensity modulation possible with IMRT.Methods: A beamlet-based inverse planning system was enhanced to combine the advantages of VMAT and IMRT into one comprehensive technique. In the hybrid strategy, baseline single-arc VMAT plans are optimized and then the current cost function gradients with respect to the beamlets are used to define a metric for predicting which beam angles would benefit from further intensity modulation. Beams with the highest metric values (called the gradient factor) are converted from VMAT apertures to IMRT fluence, and the optimization proceeds with the mixed variable set until convergence or until additional beams are selected for conversion. One phantom and two clinical cases were used to validate the gradient factor and characterize the FusionArc strategy. Comparisons were made between standard IMRT, single-arc VMAT, and FusionArc plans with one to five IMRT/hybrid beams.Results: The gradient factor was found to be highly predictive of the VMAT angles that would benefit plan quality the most from beam modulation. Over the three cases studied, a FusionArc plan with three converted beams achieved superior dosimetric quality with reductions in final cost ranging from 26.4% to 48.1% compared to single-arc VMAT. Additionally, the three beam FusionArc plans required 22.4%-43.7% fewer MU/Gy than a seven beam IMRT plan. While the FusionArc plans with five converted beams offer larger reductions in final cost-32.9%-55.2% compared to single-arc VMAT-the decrease in MU/Gy compared to IMRT was noticeably smaller at 12.2%-18.5%, when compared to IMRT.Conclusions: A hybrid VMAT/IMRT strategy was implemented to find a high quality compromise between gantry-angle and intensity-based degrees of freedom. This optimization method will allow patients to be simultaneously planned for dosimetric quality and delivery efficiency without switching between delivery techniques. Example phantom and clinical cases suggest that the conversion of only three VMAT segments to modulated beams may result in a good combination of quality and efficiency.

  1. Type B Accident Investigation of the Arc Flash at Brookhaven...

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

    event and causal factor analysis. Type B Accident Investigation of the Arc Flash at Brookhaven National Laboratory, April 14, 2006 More Documents & Publications DOE-HDBK-1092-1998...

  2. ARC-HEATED GAS FLOW EXPERIMENTS FOR HYPERSONIC PROPULSION

    E-Print Network [OSTI]

    Texas at Arlington, University of

    the Supersonic Wind Tunnel. I have enjoyed working with Rod Duke, who has been an important asset to my research to be injected into the engine combustors. To investigate this approach, the UTA Arc-Heated #12;vi Wind Tunnel

  3. Simple filtered repetitively pulsed vacuum arc plasma source

    SciTech Connect (OSTI)

    Chekh, Yu.; Zhirkov, I. S.; Delplancke-Ogletree, M. P.

    2010-02-15

    A very simple design of cathodic filtered vacuum arc plasma source is proposed. The source without filter has only four components and none of them require precise machining. The source operates in a repetitively pulsed regime, and for laboratory experiments it can be used without water cooling. Despite the simple construction, the source provides high ion current at the filter outlet reaching 2.5% of 400 A arc current, revealing stable operation in a wide pressure range from high vacuum to oxygen pressure up to more than 10{sup -2} mbar. There is no need in complicated power supply system for this plasma source, only one power supply can be used to ignite the arc, to provide the current for the arc itself, to generate the magnetic field in the filter, and provide its positive electric biasing without any additional high power resistance.

  4. Ohmic contacts for solar cells by arc plasma spraying

    DOE Patents [OSTI]

    Narasimhan, Mandayam C. (Seekonk, MA); Roessler, Barton (Barrington, RI); Loferski, Joseph J. (Providence, RI)

    1982-01-01

    The method of applying ohmic contacts to a semiconductor, such as a silicon body or wafer used in solar cells, by the use of arc plasma spraying, and solar cells resulting therefrom.

  5. Arc Reversals in Hybrid Bayesian Networks with Deterministic Variables

    E-Print Network [OSTI]

    Cinicioglu, Esma N.; Shenoy, Prakash P.

    2009-05-01

    This article discusses arc reversals in hybrid Bayesian networks with deterministic variables. Hybrid Bayesian networks contain a mix of discrete and continuous chance variables. In a Bayesian network representation, a continuous chance variable...

  6. Arc-Eager Parsing with the Tree Constraint Joakim Nivre

    E-Print Network [OSTI]

    Arc-Eager Parsing with the Tree Constraint Joakim Nivre Uppsala University Daniel Fern for greedy deterministic dependency parsers (Nivre, Hall, and Nilsson 2004; Goldberg and Nivre 2012), beam

  7. ArcGIS for Desktop Student Trial Software Instructions -Version 10.0 10.3 The ArcGIS for Desktop 1-year Student License provides a 1-year term license for ArcGIS for Desktop and Extensions

    E-Print Network [OSTI]

    O'Laughlin, Jay

    ArcGIS for Desktop Student Trial Software Instructions - Version 10.0 10.3 The ArcGIS for Desktop. Check your system requirements to make sure your computer has the hardware and software required the process of activating and downloading your ArcGIS for Desktop Student Trial software. b. Log in using your

  8. Synthesis of silicon nanotubes by DC arc plasma method

    SciTech Connect (OSTI)

    Tank, C. M.; Bhoraskar, S. V.; Mathe, V. L.

    2012-06-05

    Plasma synthesis is a novel technique of synthesis of nanomaterials as they provide high rate of production and promote metastable reactions. Very thin walled silicon nanotubes were synthesized in a DC direct arc thermal plasma reactor. The effect of parameters of synthesis i.e. arc current and presence of hydrogen on the morphology of Si nanoparticles is reported. Silicon nanotubes were characterized by Transmission Electron Microscopy (TEM), Local Energy Dispersive X-ray analysis (EDAX), and Scanning Tunneling Microscopy (STM).

  9. Role of substrate temperature at graphene synthesis in arc discharge

    E-Print Network [OSTI]

    Fang, Xiuqi; Keidar, Michael

    2015-01-01

    Substrate temperature required for synthesis of graphene in arc discharge plasma was studied. It was shown that increase of the copper substrate temperature up to melting point leads to increase in the amount of graphene production and quality of graphene sheets. Favorable range of substrate temperatures for arc-based graphene synthesis was determined in relatively narrow range of about 1340-1360K which is near the melting point of copper.

  10. Arc-Fault Detector Algorithm Evaluation Method Utilizing Prerecorded Arcing Signatures

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O O D SFederal8823 Revision 02 (CRACAprilArc-Fault Detector

  11. Arc-parallel flow within the mantle wedge: Evidence from the accreted Talkeetna arc, south central Alaska

    E-Print Network [OSTI]

    Alaska Luc Mehl and Bradley R. Hacker Department of Geological Sciences, University of California, Santa. Hacker, G. Hirth, and P. B. Kelemen, Arc-parallel flow within the mantle wedge: Evidence from

  12. ARCS Additional FirstYear PhD Student Award The Atlanta chapter of ARCS has just informed me that they will honor us with another graduate student

    E-Print Network [OSTI]

    Arnold, Jonathan

    ARCS Additional FirstYear PhD Student Award The Atlanta chapter of ARCS has just informed me meets their definition listed above. Sincerely, Harry A. Dailey, Ph.D. Professor and Director

  13. Effects of current on droplet generation and arc plasma in gas metal arc welding

    SciTech Connect (OSTI)

    Hu, J.; Tsai, H. L.

    2006-09-01

    In gas metal arc welding (GMAW), a technology using pulsed currents has been employed to achieve the one-droplet-per-pulse (ODPP) metal transfer mode with the advantages of low average currents, a stable and controllable droplet generation, and reduced spatter. In this paper, a comprehensive model was developed to study the effects of different current profiles on the droplet formation, plasma generation, metal transfer, and weld pool dynamics in GMAW. Five types of welding currents were studied, including two constant currents and three wave form currents. In each type, the transient temperature and velocity distributions of the arc plasma and the molten metal, and the shapes of the droplet and the weld pool were calculated. The results showed that a higher current generates smaller droplets, higher droplet frequency, and higher electromagnetic force that becomes the dominant factor detaching the droplet from the electrode tip. The model has demonstrated that a stable ODPP metal transfer mode can be achieved by choosing a current with proper wave form for given welding conditions.

  14. Use of a Magnetized Cascade Arc SourceUse of a Magnetized Cascade Arc Source in TCSU to Enable RMF Formation ofin TCSU to Enable RMF Formation of

    E-Print Network [OSTI]

    Washington at Seattle, University of

    erosion rate but must still be machinable. All arc discharges to date with this plasma gun have been madeUse of a Magnetized Cascade Arc SourceUse of a Magnetized Cascade Arc Source in TCSU to Enable RMF.Y. Guo, K.E. Miller Redmond Plasma Physics Laboratory, University of Washington Abstract TCSU can produce

  15. Hydrogeochemical exploration of the Tecuamburro Volcano region, Guatemala

    SciTech Connect (OSTI)

    Goff, F.; Truesdell, A.H.; Janik, C.J.; Adams, A.; Roldan-M, A.; Meeker, K. (Los Alamos National Lab., NM (USA); Geological Survey, Menlo Park, CA (USA); Los Alamos National Lab., NM (USA); Instituto Nacional de Electrificacion, Guatemala City (Guatemala). Unidad de Desarollo Geotermico; Los Alamos National Lab., NM (USA))

    1989-01-01

    Approximately 100 thermal and nonthermal water samples and 20 gas samples from springs and fumaroles have been chemically and isotopically analyzed to help evaluate the geothermal potential of the Tecuamburro Volcano region, Guatemala. Thermal waters of the acid- sulfate, steam condensate, and neutral-chloride types generally occur in restricted hydrogeologic areas: Tecuamburro-Laguna Ixpaco (acid- sulfate); andesite highland north of Tecuamburro (steam-condensate); Rio Los Esclavos (neutral-chloride). One small area of neutral-chloride springs east of the village of Los Esclavos has no relation to the Tecuamburro geothermal system. Neutral-chloride springs on the Rio Los Esclavos east and southeast of Tecuamburro show mixing with various types of groundwaters and display a maximum oxygen-18 enrichment compared to the world meteoric line of only about 1.5 parts per thousand. Maximum estimated subsurface temperatures are {le}200{degree}C. In contrast, maximum estimated subsurface temperatures based on gas compositions in the Laguna Ixpaco area are about 300{degree}C. The relation of neutral-chloride waters to the overall Tecuamburro geothermal system is not entirely resolved but we have suggested two system models. Regardless of model, we believe that a first exploration drill hole should be sited within 0.5 km of Laguna Ixpaco to tap the main geothermal reservoir or its adjacent, main upflow zone. 9 refs., 4 figs., 3 tabs.

  16. Hydrothermal changes related to earthquake activity at Mud Volcano, Yellowstone National Park, Wyoming

    SciTech Connect (OSTI)

    Pitt, A.M.; Hutchinson, R.A.

    1982-04-10

    The Mud Volcano hydrothermal area in Yellowstone National Park is near the intersection of a 20-km-long zone of northeast trending normal faults with the eastern resurgent dome within the 600,000-year-odd Yellowstone caldera. Recent crustal uplift along the northeast trending axis of the caldera is at a maximum (700 mm since 1923) near the Mud Volcano area. From 1973 through April 1978, less than 10 earthquakes (largest M 2.4) were located within 3 km of the Mud Volcano area. In May 1978, earthquakes began occurring beneath the hydrothermal area at depths of 1 to 5 km. The seismic activity continued until the end of November with intense swarms (100 events per hour) occurring on October 23 and November 7. The largest event (M 3.1) occured on November 14 and at least 8 events were M 2.5 or larger. In December 1978, heat flux in the Mud Volcano hydrothermal features began increasing along a 2-km-long northeast trending zone. Existing mud cauldrons became more active, new mud cauldrons and fumeroles were formed, and vegetation (primarily lodgepole pine) was killed by increased soil temperature. The increase in heat flux continued through July 1979 then gradually declined, reaching the early 1978 level by June 1980. The spatial and temporal association of earthquakes and increased hydrothermal activity at Mud Volcano suggests that the seismic activity expanded preexisting fracture systems, premitting increased fluid flow from depths of several kilometers.

  17. Oceanography Vol. 19, No. 1, Mar. 2006142 After lying dormant for hundreds of years, a seaside volcano erupts, splitting its cin-

    E-Print Network [OSTI]

    Grilli, Stphan T.

    . The volcanoes on the islands of Stromboli (Tinti and Bortolucci, 2001) and La Palma in the Canary Islands (Ward

  18. Dynamic Resource Allocation with the arcControlTower

    E-Print Network [OSTI]

    Filipcic, Andrej; The ATLAS collaboration; Nilsen, Jon Kerr

    2015-01-01

    Distributed computing resources available for high-energy physics research are becoming less dedicated to one type of workflow and researchers workloads are increasingly exploiting modern computing technologies such as parallelism. The current pilot job management model used by many experiments relies on static dedicated resources and cannot easily adapt to these changes. The model used for ATLAS in Nordic countries and some other places enables a flexible job management system based on dynamic resources allocation. Rather than a fixed set of resources managed centrally, the model allows resources to be requested on the fly. The ARC Computing Element (ARC-CE) and ARC Control Tower (aCT) are the key components of the model. The aCT requests jobs from the ATLAS job management system (PanDA) and submits a fully-formed job description to ARC-CEs. ARC-CE can then dynamically request the required resources from the underlying batch system. In this paper we describe the architecture of the model and the experienc...

  19. CHEP2015: Dynamic Resource Allocation with arcControlTower

    E-Print Network [OSTI]

    Filipcic, Andrej; The ATLAS collaboration; Nilsen, Jon Kerr

    2015-01-01

    Distributed computing resources available for high-energy physics research are becoming less dedicated to one type of workflow and researchers workloads are increasingly exploiting modern computing technologies such as parallelism. The current pilot job management model used by many experiments relies on static dedicated resources and cannot easily adapt to these changes. The model used for ATLAS in Nordic countries and some other places enables a flexible job management system based on dynamic resources allocation. Rather than a fixed set of resources managed centrally, the model allows resources to be requested on the fly. The ARC Computing Element (ARC-CE) and ARC Control Tower (aCT) are the key components of the model. The aCT requests jobs from the ATLAS job mangement system (Panda) and submits a fully-formed job description to ARC-CEs. ARC-CE can then dynamically request the required resources from the underlying batch system. In this paper we describe the architecture of the model and the experience...

  20. Graphite electrode arc melter demonstration Phase 2 test results

    SciTech Connect (OSTI)

    Soelberg, N.R.; Chambers, A.G.; Anderson, G.L.; O`Connor, W.K.; Oden, L.L.; Turner, P.C.

    1996-06-01

    Several U.S. Department of Energy organizations and the U.S. Bureau of Mines have been collaboratively conducting mixed waste treatment process demonstration testing on the near full-scale graphite electrode submerged arc melter system at the Bureau`s Albany (Oregon) Research Center. An initial test series successfully demonstrated arc melter capability for treating surrogate incinerator ash of buried mixed wastes with soil. The conceptual treatment process for that test series assumed that buried waste would be retrieved and incinerated, and that the incinerator ash would be vitrified in an arc melter. This report presents results from a recently completed second series of tests, undertaken to determine the ability of the arc melter system to stably process a wide range of {open_quotes}as-received{close_quotes} heterogeneous solid mixed wastes containing high levels of organics, representative of the wastes buried and stored at the Idaho National Engineering Laboratory (INEL). The Phase 2 demonstration test results indicate that an arc melter system is capable of directly processing these wastes and could enable elimination of an up-front incineration step in the conceptual treatment process.

  1. Non-Equilibrium Modeling of Arc Plasma Torches

    E-Print Network [OSTI]

    Trelles, J P; Heberlein, J V R

    2013-01-01

    A two-temperature thermal non-equilibrium model is developed and applied to the three-dimensional and time-dependent simulation of the flow inside a DC arc plasma torch. A detailed comparison of the results of the non-equilibrium model with those of an equilibrium model is presented. The fluid and electromagnetic equations in both models are approximated numerically in a fully-coupled approach by a variational multi-scale finite element method. In contrast to the equilibrium model, the non-equilibrium model did not need a separate reattachment model to produce an arc reattachment process and to limit the magnitude of the total voltage drop and arc length. The non-equilibrium results show large non-equilibrium regions in the plasma - cold-flow interaction region and close to the anode surface. Marked differences in the arc dynamics, especially in the arc reattachment process, and in the magnitudes of the total voltage drop and outlet temperatures and velocities between the models are observed. The non-equilibr...

  2. Dynamic voltage-current characteristics for a water jet plasma arc

    SciTech Connect (OSTI)

    Yang Jiaxiang; Lan Sheng; Xu Zuoming

    2008-05-05

    A virtual instrument technology is used to measure arc current, arc voltage, dynamic V-I characteristics, and nonlinear conductance for a cone-shaped water jet plasma arc under ac voltage. Experimental results show that ac arc discharge mainly happens in water vapor evaporated from water when heated. However, due to water's cooling effect and its conductance, arc conductance, reignition voltage, extinguish voltage, and current zero time are very different from those for ac arc discharge in gas work fluid. These can be valuable to further studies on mechanism and characteristics of plasma ac discharge in water, and even in gas work fluid.

  3. Deep-Sea Research I 53 (2006) 17621771 Gouge marks on deep-sea mud volcanoes in the eastern

    E-Print Network [OSTI]

    Hooker, Sascha K.

    2006-01-01

    Deep-Sea Research I 53 (2006) 17621771 Gouge marks on deep-sea mud volcanoes in the eastern in the eastern Mediterranean Sea. The marks consist of a central groove (about 10 cm deep and 12 m long like the deep-diving whales. The characteristic high acoustic backscatter of the mud volcanoes would

  4. Measuring large topographic change with InSAR: Lava thicknesses, extrusion rate and subsidence rate at Santiaguito volcano, Guatemala

    E-Print Network [OSTI]

    Elliott, John

    at Santiaguito volcano, Guatemala S.K. Ebmeier a,n , J. Biggs b , T.A. Mather a , J.R. Elliott a , G. Wadge c , F. We apply this to Santiaguito volcano, Guatemala, and measure increases in lava thickness of up to 140

  5. Measuring Sulphur Dioxide (SO2) Emissions in October, 2010 Catastrophic Eruption from Merapi Volcano in Java, Indonesia

    E-Print Network [OSTI]

    Gilbes, Fernando

    Volcano in Java, Indonesia with Ozone Monitoring Instrument (OMI) Jos A. Morales-Collazo Geology This paper discusses sulfur dioxide (SO2) cloud emissions from Merapi Volcano in Java, Indonesia during, Indonesia. In October 26th , 2010, a catastrophic eruption was reported from Merapi causing nearly 386

  6. Strike-slip faulting as a trigger mechanism for overpressure release through piercement structures. Implications for the Lusi mud volcano, Indonesia

    E-Print Network [OSTI]

    Mazzini, Adriano

    . Implications for the Lusi mud volcano, Indonesia A. Mazzini a,*, A. Nermoen a , M. Krotkiewski a , Y 2009 Accepted 12 March 2009 Available online 19 March 2009 Keywords: Java, Indonesia Lusi mud volcano the newly formed Lusi mud volcano in Indonesia (Mazzini et al., 2007). Lusi became active the 29th of May

  7. Strike-slip faulting as a trigger mechanism for overpressure release through piercement structures. Implications for the Lusi mud volcano, Indonesia

    E-Print Network [OSTI]

    Podladchikov, Yuri

    . Implications for the Lusi mud volcano, Indonesia A. Mazzini a,*, A. Nermoen a , M. Krotkiewski a , Y 2009 Accepted 12 March 2009 Available online xxx Keywords: Java, Indonesia Lusi mud volcano Faulting volcano in Indonesia (Mazzini et al., 2007). Lusi became active the 29th of May 2006 on the Java Island

  8. Parallel vacuum arc discharge with microhollow array dielectric and anode

    SciTech Connect (OSTI)

    Feng, Jinghua; Zhou, Lin; Fu, Yuecheng; Zhang, Jianhua; Xu, Rongkun; Chen, Faxin; Li, Linbo; Meng, Shijian

    2014-07-15

    An electrode configuration with microhollow array dielectric and anode was developed to obtain parallel vacuum arc discharge. Compared with the conventional electrodes, more than 10 parallel microhollow discharges were ignited for the new configuration, which increased the discharge area significantly and made the cathode eroded more uniformly. The vacuum discharge channel number could be increased effectively by decreasing the distances between holes or increasing the arc current. Experimental results revealed that plasmas ejected from the adjacent hollow and the relatively high arc voltage were two key factors leading to the parallel discharge. The characteristics of plasmas in the microhollow were investigated as well. The spectral line intensity and electron density of plasmas in microhollow increased obviously with the decease of the microhollow diameter.

  9. Muon Acceleration with RLA and Non-scaling FFAG Arcs

    SciTech Connect (OSTI)

    Vasiliy Morozov,Alex Bogacz,Dejan Trbojevic

    2010-05-01

    Recirculating Linear Accelerators (RLA) are the most likely means to achieve the rapid acceleration of shortlived muons to multi-GeV energies required for Neutrino Factories and TeV energies required for Muon Colliders. In this paper, we present a novel return-arc optics design based on a Non Scaling Fixed Field Alternating Gradient (NS-FFAG) lattice that allows 5 and 9 GeV/c muons of both charges to be transported in the same string of magnets. The return arcs are made up of super cells with each super cell consisting of three triplets. By employing combined function magnets with dipole, quadrupole, sextupole and octupole magnetic field components, each super cell is designed to be achromatic and to have zero initial and final periodic orbit offsets for both 5 and 9 GeV/c muon momenta. This solution would reduce the number of arcs by a factor of 2, simplifying the overall design.

  10. Muon acceleration with RLA and non-scaling FFAG ARCS

    SciTech Connect (OSTI)

    Morozov, V.S.; Trbojevic, D.; Bogacz, A.

    2010-05-23

    Recirculating Linear Accelerators (RLA) are the most likely means to achieve the rapid acceleration of short-lived muons to multi-GeV energies required for Neutrino Factories and TeV energies required for Muon Colliders. In this paper, we present a novel return-arc optics design based on a Non Scaling Fixed Field Alternating Gradient (NS-FFAG) lattice that allows 5 and 9 GeV/c muons of both charges to be transported in the same string of magnets. The return arcs are made up of super cells with each super cell consisting of three triplets. By employing combined function magnets with dipole, quadrupole, sextupole and octupole magnetic field components, each super cell is designed to be achromatic and to have zero initial and final periodic orbit offsets for both 5 and 9 GeV/c muon momenta. This solution would reduce the number of arcs by a factor of 2, simplifying the overall design.

  11. High-bandwidth continuous-flow arc furnace

    DOE Patents [OSTI]

    Hardt, D.E.; Lee, S.G.

    1996-08-06

    A high-bandwidth continuous-flow arc furnace for stream welding applications includes a metal mass contained in a crucible having an orifice. A power source charges an electrode for generating an arc between the electrode and the mass. The arc heats the metal mass to a molten state. A pressurized gas source propels the molten metal mass through the crucible orifice in a continuous stream. As the metal is ejected, a metal feeder replenishes the molten metal bath. A control system regulates the electrode current, shielding gas pressure, and metal source to provide a continuous flow of molten metal at the crucible orifice. Independent control over the electrode current and shield gas pressure decouples the metal flow temperature and the molten metal flow rate, improving control over resultant weld characteristics. 4 figs.

  12. High-bandwidth continuous-flow arc furnace

    DOE Patents [OSTI]

    Hardt, David E. (Concord, MA); Lee, Steven G. (Ann Arbor, MI)

    1996-01-01

    A high-bandwidth continuous-flow arc furnace for stream welding applications includes a metal mass contained in a crucible having an orifice. A power source charges an electrode for generating an arc between the electrode and the mass. The arc heats the metal mass to a molten state. A pressurized gas source propels the molten metal mass through the crucible orifice in a continuous stream. As the metal is ejected, a metal feeder replenishes the molten metal bath. A control system regulates the electrode current, shielding gas pressure, and metal source to provide a continuous flow of molten metal at the crucible orifice. Independent control over the electrode current and shield gas pressure decouples the metal flow temperature and the molten metal flow rate, improving control over resultant weld characteristics.

  13. Achieving high mobility ZnO:Al at very high growth rates by dc filtered cathodic arc deposition

    E-Print Network [OSTI]

    Mendelsberg, Rueben

    2013-01-01

    scale heating in cathodic arc plasma deposition. Appl. Phys.modest 25-70 A dc. The arc plasma was ?ltered using aenergy of the cathodic arc plasma is utilized for ?lm growth

  14. Improved structural and electrical properties of thin ZnO:Al films by dc filtered cathodic arc deposition

    E-Print Network [OSTI]

    Zhu, Yuankun

    2013-01-01

    scale heating in cathodic arc plasma deposition. Appl. Phys.using filtered cathodic arc plasmas. Vacuum 67 673 (2002).to rid cathodic arc plasma of macro- and nanoparticles: a

  15. Multi-cathode metal vapor arc ion source

    DOE Patents [OSTI]

    Brown, Ian G. (1088 Woodside Rd., Berkeley, CA 94708); MacGill, Robert A. (645 Kern St., Richmond, CA 94805)

    1988-01-01

    An ion generating apparatus utilizing a vacuum chamber, a cathode and an anode in the chamber. A source of electrical power produces an arc or discharge between the cathode and anode. The arc is sufficient to vaporize a portion of the cathode to form a plasma. The plasma is directed to an extractor which separates the electrons from the plasma, and accelerates the ions to produce an ion beam. One embodiment of the appaatus utilizes a multi-cathode arrangement for interaction with the anode.

  16. Graphite electrode DC arc furnace. Innovative technology summary report

    SciTech Connect (OSTI)

    1999-05-01

    The Graphite Electrode DC Arc Furnace (DC Arc) is a high-temperature thermal process, which has been adapted from a commercial technology, for the treatment of mixed waste. A DC Arc Furnace heats waste to a temperature such that the waste is converted into a molten form that cools into a stable glassy and/or crystalline waste form. Hazardous organics are destroyed through combustion or pyrolysis during the process and the majority of the hazardous metals and radioactive components are incorporated in the molten phase. The DC Arc Furnace chamber temperature is approximately 593--704 C and melt temperatures are as high as 1,500 C. The DC Arc system has an air pollution control system (APCS) to remove particulate and volatiles from the offgas. The advantage of the DC Arc is that it is a single, high-temperature thermal process that minimizes the need for multiple treatment systems and for extensive sorting/segregating of large volumes of waste. The DC Arc has the potential to treat a wide range of wastes, minimize the need for sorting, reduce the final waste volumes, produce a leach resistant waste form, and destroy organic contaminants. Although the DC arc plasma furnace exhibits great promise for treating the types of mixed waste that are commonly present at many DOE sites, several data and technology deficiencies were identified by the Mixed Waste Focus Area (MWFA) regarding this thermal waste processing technique. The technology deficiencies that have been addressed by the current studies include: establishing the partitioning behavior of radionuclides, surrogates, and hazardous metals among the product streams (metal, slag, and offgas) as a function of operating parameters, including melt temperature, plenum atmosphere, organic loading, chloride concentration, and particle size; demonstrating the efficacy of waste product removal systems for slag and metal phases; determining component durability through test runs of extended duration, evaluating the effect of feed composition variations on process operating conditions and slag product performance; and collecting mass balance and operating data to support equipment and instrument design.

  17. Thermocapillary and arc phenomena in stainless steel welds

    SciTech Connect (OSTI)

    Pierce, S.W.

    1993-10-01

    Goal was to study effect of power level and distribution on thermocapiilary-induced weld shape and of arc factors on weld shape. Thermocapillarity was apparent in both conduction mode EB welds and GTA welds, particularly in the former. A non-Gaussian arc distribution is suggested for accounting for the differences between the twoss processes. At higher current levels (200--300 A), plasma shear force also contributes to weld shape development. Evidence suggests that thermocapillary flow reversal is not a factor in normal GTA welds; EDB flow reversal occurs only at high power density levels where the keyhole mode is present.

  18. Rates of tectonic and magmatic processes in the North Cascades continental magmatic arc

    E-Print Network [OSTI]

    Matzel, Jennifer E. Piontek, 1973-

    2004-01-01

    Continental magmatic arcs are among the most dynamic. geologic systems, and documentation of the magmatic, thermal, and tectonic evolution of arcs is essential for understanding the processes of magma generation, ascent ...

  19. Emission spectra analysis of arc plasma for synthesis of carbon nanostructures in various magnetic conditions

    SciTech Connect (OSTI)

    Li Jian; Kundrapu, Madhusudhan; Shashurin, Alexey; Keidar, Michael

    2012-07-15

    Arc discharge supported by the erosion of anode materials is one of the most practical and efficient methods to synthesize various high-quality carbon nanostructures. By introducing a non-uniform magnetic field in arc plasmas, high-purity single-walled carbon nanotubes (SWCNT) and large-scale graphene flakes can be obtained in a single step. In this paper, ultraviolet-visible emission spectra of arc in different spots under various magnetic conditions are analyzed to provide an in situ investigation for transformation processes of evaporated species and growth of carbon nanostructures in arc. Based on the arc spectra of carbon diatomic Swan bands, vibrational temperature in arc is determined. The vibrational temperature in arc center was measured around 6950 K, which is in good agreement with our simulation results. Experimental and simulation results suggest that SWCNT are formed in the arc periphery region. Transmission electronic microscope and Raman spectroscope are also employed to characterize the properties of carbon nanostructures.

  20. Optical emission spectroscopy of metal vapor dominated laser-arc hybrid welding plasma

    SciTech Connect (OSTI)

    Ribic, B.; DebRoy, T.; Burgardt, P.

    2011-04-15

    During laser-arc hybrid welding, plasma properties affect the welding process and the weld quality. However, hybrid welding plasmas have not been systematically studied. Here we examine electron temperatures, species densities, and electrical conductivity for laser, arc, and laser-arc hybrid welding using optical emission spectroscopy. The effects of arc currents and heat source separation distances were examined because these parameters significantly affect weld quality. Time-average plasma electron temperatures, electron and ion densities, electrical conductivity, and arc stability decrease with increasing heat source separation distance during hybrid welding. Heat source separation distance affects these properties more significantly than the arc current within the range of currents considered. Improved arc stability and higher electrical conductivity of the hybrid welding plasma result from increased heat flux, electron temperatures, electron density, and metal vapor concentrations relative to arc or laser welding.

  1. Charge-State-Resolved Ion Energy Distribution Functions of Cathodic Vacuum Arcs: A Study Involving the Plasma Potential and Biased Plasmas

    E-Print Network [OSTI]

    Anders, Andre; Oks, Efim

    2006-01-01

    velocity in vacuum arc plasmas by arc current perturbationwith a pulsed cathodic arc plasma source of the minigunproduced by a cathodic arc plasma source of the minigun

  2. THE CONTROL OF A HIGH-POWER NEUTRAL BEAM GENERATOR BY MEANS OF ARC-CURRENT REGULATION

    E-Print Network [OSTI]

    Lietzke, A.F.

    2010-01-01

    A HIGH-POWER NEUTRAL BEAM GENERATOR BY MEANS OF ARC-CURRENTA HIGH-POWER NEUTRAL BEAM GENERATOR BY MEANS OF ARC-CURRENT

  3. A comparison of the marginal adaptation of cathode-arc vapor-deposited titanium and cast base metal copings.

    E-Print Network [OSTI]

    Wu, Jean C; Lai, Li-Chung; Sheets, Cherilyn G; Earthman, James; Newcomb, Robert

    2011-01-01

    of Prosthetic Dentistry plasma arc on the cathode surface.arc deposition consists of a titanium cathode material and metal plasma

  4. Physics 619: Fields II Fall 2014 Room: ARC-212

    E-Print Network [OSTI]

    Gustafsson, Torgny

    Physics 619: Fields II Fall 2014 Room: ARC-212 Time: Monday, Thursday 10:20-11:40 AM Instructor: Sergei Lukyanov office: Serin E364 tel: (848) 445-9060 (office) e-mail: sergei@physics.rutgers.edu (the to the published version) can be found at http://web.physics.ucsb.edu/ mark/ms-qft-DRAFT.pdf Homework

  5. Connecting ARC/INFO \\Lambda and SNACTor Project Report y

    E-Print Network [OSTI]

    Krovi, Venkat

    This report describes an interface between ARC/INFO, a geographic information management system, and SNACTor of how an interaction with a geographic 2 #12; information management system could be done in a small and Hsuehcheng Chou x National Center for Geographic Information and Analysis June 8, 1992 Abstract

  6. Self-organisation Processes In The Carbon ARC For Nanosynthis

    SciTech Connect (OSTI)

    Ng, J.; Raitses, Yefgeny

    2014-02-02

    The atmospheric pressure carbon arc in inert gases such as helium is an important method for the production of nanomaterials. It has recently been shown that the formation of the carbon deposit on the cathode from gaseous carbon plays a crucial role in the operation of the arc, reaching the high temperatures necessary for thermionic emission to take place even with low melting point cathodes. Based on observed ablation and deposition rates, we explore the implications of deposit formation on the energy balance at the cathode surface, and show how the operation of the arc is self-organised process. Our results suggest that the can arc operate in two di erent regimes, one of which has an important contribution from latent heat to the cathode energy balance. This regime is characterised by the enhanced ablation rate, which may be favourable for high yield synthesis of nanomaterials. The second regime has a small and approximately constant ablation rate with a negligible contribution from latent heat.

  7. Self-organisation Processes In The Carbon ARC For Nanosynthis

    SciTech Connect (OSTI)

    Ng, Jonathan; Raitses, Yevgeny

    2014-02-26

    The atmospheric pressure carbon arc in inert gases such as helium is an important method for the production of nanomaterials. It has recently been shown that the formation of the carbon deposit on the cathode from gaseous carbon plays a crucial role in the operation of the arc, reaching the high temperatures necessary for thermionic emission to take place even with low melting point cathodes. Based on observed ablation and deposition rates, we explore the implications of deposit formation on the energy balance at the cathode surface, and show how the operation of the arc is self-organised process. Our results suggest that the can arc operate in two di erent regimes, one of which has an important contribution from latent heat to the cathode energy balance. This regime is characterised by the enhanced ablation rate, which may be favourable for high yield synthesis of nanomaterials. The second regime has a small and approximately constant ablation rate with a negligible contribution from latent heat.

  8. Supersonic Argon Flow In An Arc Plasma Source

    SciTech Connect (OSTI)

    Izrar, B.; Dudeck, M.; Andre, P.; Elchinger, M. F.; Aubreton, J.

    2006-01-15

    The plasma properties inside a D.C. arc-jet operating with argon is analysed by means of a continuum description taking into account non equilibrium ionization processes and dissipative effects. The relaxation of the different physical processes inside the nozzle and the evolution of the Mach number are aanalysed.

  9. H2O subduction beyond arcs Bradley R. Hacker

    E-Print Network [OSTI]

    Hacker, Bradley R.

    H2O subduction beyond arcs Bradley R. Hacker Department of Earth Science, University of California, Santa Barbara, California 93109-9630, USA (hacker@geol.ucsb.edu) [1] The amount of H2O subducted). Received 31 May 2007; Revised 26 October 2007; Accepted 7 December 2007; Published 5 March 2008. Hacker, B

  10. Pulse thermal processing of functional materials using directed plasma arc

    DOE Patents [OSTI]

    Ott, Ronald D. (Knoxville, TN); Blue, Craig A. (Knoxville, TN); Dudney, Nancy J. (Knoxville, TN); Harper, David C. (Kingston, TN)

    2007-05-22

    A method of thermally processing a material includes exposing the material to at least one pulse of infrared light emitted from a directed plasma arc to thermally process the material, the pulse having a duration of no more than 10 s.

  11. The Arc type Dependence Representation in Polaris Naraig Manjikian

    E-Print Network [OSTI]

    Padua, David

    The Arc type Dependence Representation in Polaris Naraig Manjikian Department of Electrical and Computer Engineering University of Toronto Toronto, Ontario, Canada M5S 1A4 May 20, 1995 1 Introduction in a dependence pair, i.e., there is no redundant information. The implication of this is that both a source

  12. End of Year reporting & Carry forward process for ARC & NHMRC

    E-Print Network [OSTI]

    Blennerhassett, Peter

    End of Year reporting & Carry forward process for ARC & NHMRC PREPARATION · September - GMO sends reminder email to CIs to review research account expenditure · October - GMO sends advice to all CIs Financial Statement amounts and GMO classifies accounts according to reporting required; % of carry forward

  13. Anode Sheath Switching in a Carbon Nanotube Arc Plasma

    SciTech Connect (OSTI)

    Abe Fetterman, Yevgeny Raitses, and Michael Keidar

    2008-04-08

    The anode ablation rate is investigated as a function of anode diameter for a carbon nanotube arc plasma. It is found that anomalously high ablation occurs for small anode diameters. This result is explained by the formation of a positive anode sheath. The increased ablation rate due to this positive anode sheath could imply greater production rate for carbon nanotubes.

  14. Study of the spray to globular transition in gas metal arc welding: a spectroscopic investigation

    E-Print Network [OSTI]

    Study of the spray to globular transition in gas metal arc welding: a spectroscopic investigation of the spray to globular transition in gas metal arc welding: a spectroscopic investigation F Valensi1.iop.org/JPhysD/46/224005 Abstract The gas metal arc welding (GMAW) process is strongly influenced by the composition

  15. Proposal of an Arc Detection Technique Based on RF Measurements for the ITER ICRF Antenna

    SciTech Connect (OSTI)

    Huygen, S.; Dumortier, P.; Durodie, F.; Messiaen, A.; Vervier, M.; Vrancken, M.

    2011-12-23

    RF arc detection is a key operational and safety issue for the ICRF system on ITER. Indeed the high voltages inside the antenna put it at risk of arcing, which could cause substantial damage. This paper describes the various possibilities explored by circuit simulation and the strategy now considered to protect the ITER ICRF antenna from RF arcs.

  16. Comparison of Different Arc Detection Methods during Plasma Operations with ICRF Heating on ASDEX Upgrade

    SciTech Connect (OSTI)

    D'Inca, R.; Assas, S.; Bobkov, V.; Braun, F.; Eckert, B.; Noterdaeme, J.-M.

    2007-09-28

    The Sub-Harmonic Arc Detection (SHAD) system used on ASDEX-Upgrade has been designed with the double objective to detect arcs on the ICRF system and to discriminate them from plasma transients like ELMs. This preliminary study focuses on the achievement of these requirements by analyzing and comparing the behavior of the SHAD with existing arc detectors in operation on AUG.

  17. Sediment Budget Analysis System (SBAS) for ArcGIS 10 -User's Guide Page 1 of 50

    E-Print Network [OSTI]

    US Army Corps of Engineers

    Sediment Budget Analysis System (SBAS) for ArcGIS 10 - User's Guide Page 1 of 50 CESAM-OPJ-GIS Document current as of June 27, 2012 10:09 AM Sediment Budget Analysis System (SBAS) for ArcGIS 10 User's Guide D R AFT #12;Sediment Budget Analysis System (SBAS) for ArcGIS 10 - User's Guide Page 2 of 50 CESAM

  18. CREATING DYNAMIC EQUIVALENT PV CIRCUIT MODELS WITH IMPEDANCE SPECTROSCOPY FOR ARC FAULT MODELING

    E-Print Network [OSTI]

    CREATING DYNAMIC EQUIVALENT PV CIRCUIT MODELS WITH IMPEDANCE SPECTROSCOPY FOR ARC FAULT MODELING (NEC ) requires new photovoltaic (PV) systems on or penetrating a building to include a listed arc of the arcing frequencies through PV components despite the potential for modules and other PV components

  19. Electrical Simulations of Series and Parallel PV Arc-Faults Jack Flicker and Jay Johnson

    E-Print Network [OSTI]

    Electrical Simulations of Series and Parallel PV Arc-Faults Jack Flicker and Jay Johnson Sandia residential and commercial rooftop fires. The National Electrical Code (NEC) added section 690.11 to mitigate the electrical behavior of the PV system during series and parallel arc-faults to (a) understand the arcing power

  20. The impulse response of a high-speed jet forced with localized arc filament plasma actuators

    E-Print Network [OSTI]

    Colonius, Tim

    The impulse response of a high-speed jet forced with localized arc filament plasma actuators arc filament plasma actuators Aniruddha Sinha,1 Hind Alkandry,2 Martin Kearney-Fischer,3 Mo Samimy,2,a to impulsive forcing with arc-filament-plasma actuators. The impulse response is obtained with forcing Strouhal

  1. Parametric Study of PV Arc-Fault Generation Methods and Analysis of Conducted DC Spectrum

    E-Print Network [OSTI]

    Parametric Study of PV Arc-Fault Generation Methods and Analysis of Conducted DC Spectrum Jay photovoltaic (PV) direct current (DC) arc- fault detectors use the frequency content of the PV system to detect by different PV arcs in the field. In this investigation, we (a) discuss the differences in establishing

  2. SLOPE STABILITY ANALYSIS OF THE ILIAMNA VOLCANO, ALASKA, USING ASTER TIR, SRTM DEM, AND AEROMAGNETIC DATA

    E-Print Network [OSTI]

    areas at risk for slope failure, which correlate well to the geologic field studies. These scripts can. al. 1997). These seismic stations work well but require maintenance; after the 1996 seismic swarm risk. Many of these volcanoes will be mapped geologically for the first time during the set up

  3. On the interaction of Tropical Cyclone Flossie and emissions from Hawaii's Kilauea volcano

    E-Print Network [OSTI]

    Businger, Steven

    On the interaction of Tropical Cyclone Flossie and emissions from Hawaii's Kilauea volcano Andre Pattantyus1 and Steven Businger1 1 Department of Meteorology, University of Hawai`i at Mnoa, Honolulu, Hawaii et al. [2013]. Given the persistent northeast trade winds in Hawai`i, the emissions cause frequent

  4. Steady subsidence of Medicine Lake volcano, northern California, revealed by repeated leveling surveys

    E-Print Network [OSTI]

    Steady subsidence of Medicine Lake volcano, northern California, revealed by repeated leveling) in 1954 and 1989 show that the summit area subsided by as much as 302 30 mm (8.6 0.9 mm in the earlier analysis of the same data by Dzurisin et al. [1991], who reported the subsidence rate as 11.1 1

  5. Seismic interpretation and classification of mud volcanoes of the South Caspian Basin, offshore Azerbaijan.

    E-Print Network [OSTI]

    Yusifov, Mehdi Zahid

    2005-11-01

    development in the South Caspian Basin is generally linked to faults, which in some instances are detached at the basement level. By using interpreted seismic surfaces it is possible to determine relative time of mud flows from the mud volcanoes. Timing of mud...

  6. The magmatic plumbing system beneath Santiaguito Volcano, Guatemala Jeannie A.J. Scott a,

    E-Print Network [OSTI]

    Rose, William I.

    The magmatic plumbing system beneath Santiaguito Volcano, Guatemala Jeannie A.J. Scott a, , Tamsin, Guatemala City, Guatemala a b s t r a c ta r t i c l e i n f o Article history: Received 9 September 2011 storage Ascent path The silicic dome complex of Santiaguito, Guatemala, has exhibited continuous extrusive

  7. Modeling study of growth and potential geohazard for LUSI mud volcano: East Java, Indonesia

    E-Print Network [OSTI]

    Manga, Michael

    Modeling study of growth and potential geohazard for LUSI mud volcano: East Java, Indonesia Bambang., Wisma Mulia 22nd Floor, JI. Jend. Gatot Subroto 42, 12710 Jakarta, Indonesia b Bakosurtanal, Jl. Jakarta-Bogor Km. 46, 16911 Cibinong, Indonesia c Applied Geology Research Division, Institute of Technology

  8. Triggering and dynamic evolution of the LUSI mud volcano, Indonesia A. Mazzini a,, H. Svensen a

    E-Print Network [OSTI]

    Svensen, Henrik

    Triggering and dynamic evolution of the LUSI mud volcano, Indonesia A. Mazzini a,, H. Svensen a , G Claude-Bernard UMR 5125 CNRS, 2, rue Dubois, 69622 Villeurbanne cedex, France d Volcanic Basin Petroleum Subroto 42, 12710, Jakarta Indonesia Received 20 March 2007; received in revised form 12 June 2007

  9. Evolution of large shield volcanoes on Venus Robert R. Herrick1

    E-Print Network [OSTI]

    Herrick, Robert R.

    Evolution of large shield volcanoes on Venus Robert R. Herrick1 Lunar and Planetary Institute methods. Citation: Herrick, R. R., J. Dufek, and P. J. McGovern (2005), Evolution of large shield database and expanded it to include ``Type 2'' coronae, features with minimal surface fracturing

  10. SURFACE LOADING AFFECTS INTERNAL PRESSURE SOURCE CHARACTERISTICS DERIVED FROM VOLCANO DEFORMATION SIGNALS

    E-Print Network [OSTI]

    Grapenthin, Ronni

    for subsidence with a load will, e.g. result in values for verti- cal displacement at each grid point). Hence, short wavelength features of complex loads such as lava flows are lost in recorded deformationSURFACE LOADING AFFECTS INTERNAL PRESSURE SOURCE CHARACTERISTICS DERIVED FROM VOLCANO DEFORMATION

  11. Stress magnitude and its temporal variation at Mt. Asama Volcano, Japan, from seismic anisotropy and GPS

    E-Print Network [OSTI]

    Utrecht, Universiteit

    Stress magnitude and its temporal variation at Mt. Asama Volcano, Japan, from seismic anisotropy stress Japan The Earth's stress regime is fundamental to its physical processes, yet few methods can determine absolute stress, and measurements of temporal variations in stress are controversial. The Global

  12. ASH FALL TERMS AND PUBLIC WARNING MESSAGES DURING THE ONGOING ERUPTION OF REDOUBT VOLCANO

    E-Print Network [OSTI]

    ASH FALL TERMS AND PUBLIC WARNING MESSAGES DURING THE ONGOING ERUPTION OF REDOUBT VOLCANO The National Weather Service and AVO have developed the following terminology to describe expected ash fall events. Depending on the amount of ash expected, the National Weather Service will issue a different type

  13. TQ1. Volcanoes/Earthquakes How can we help predict and mitigate earthquake and

    E-Print Network [OSTI]

    Christian, Eric

    TQ1. Volcanoes/Earthquakes How can we help predict and mitigate earthquake and volcanic hazards potentially effective information to aid in predicting possible eruptions and improve earthquake forecasts. How can we predict and mitigate earthquake and volcanic hazards through detection of transient thermal

  14. Glass Inclusions in Mariana Arc Phenocrysts: A New Perspective on Magmatic Evolution in a Typical Intra-oceanic Arc1

    E-Print Network [OSTI]

    Stern, Robert J.

    Glass Inclusions in Mariana Arc Phenocrysts: A New Perspective on Magmatic Evolution in a Typical at Dallas, Box 830688, Richardson, TX 75083-0688, USA A B S T R A C T Major element compositions of glass of these lavas reflects accumulation of plagioclase. Glass inclusions also show the common occurrence of felsic

  15. Arc Basalt Simulator version 2, a simulation for slab dehydration and fluid-fluxed mantle melting for arc

    E-Print Network [OSTI]

    Stern, Robert J.

    @jamstec.go.jp) Bradley R. Hacker Department of Earth Science, University of California, Santa Barbara, California 93106-9630, USA (hacker@geol.ucsb.edu) Peter E. van Keken Department of Geological Sciences, University. Hacker, P. E. van Keken, H. Kawabata, T. Yoshida, and R. J. Stern (2009), Arc Basalt Simulator version 2

  16. In situ observations of the "preexisting auroral arc" by THEMIS all sky imagers and the FAST spacecraft

    E-Print Network [OSTI]

    California at Berkeley, University of

    ) The preexisting arc is located 1 $2 poleward of the equatorward edge of the 1 keV electron plasma sheetIn situ observations of the "preexisting auroral arc" by THEMIS all sky imagers and the FAST involve brightening followed by poleward expansion of a discrete auroral arc. The arc that brightens

  17. Eruption dynamics within an emergent subglacial setting: a case study of the 2004 eruption of Grmsvtn volcano, Iceland

    E-Print Network [OSTI]

    Jude-Eton, Tanya Chantal; Eton, Tanya Chantal Jude

    2013-07-01

    The November 2004 explosive eruption of Grmsvtn volcano, Iceland (G2004) commenced as a subglacial event within the interior of the Vatnajkull ice cap before breaking through the ice cover to generate a 6-10 km high ...

  18. Multistage CSR microbunching gain development in transport or recirculation arcs

    E-Print Network [OSTI]

    Tsai, Cheng-Ying; Li, Rui; Tennant, Chris

    2015-01-01

    Coherent synchrotron radiation (CSR) induced microbunching instability has been one of the most challenging issues in the design of modern accelerators. A linear Vlasov solver has been developed [1] and applied to investigate the physical processes of microbunching gain amplification for several example lattices [2]. In this paper, by further extending the concept of stage gain as proposed by Huang and Kim [3], we develop a method to characterize the microbunching development in terms of stage orders that allow the quantitative comparison of optics impacts on microbunching gain for different lattices. We find that the microbunching instability in our demonstrated arcs has a distinguishing feature of multistage amplification (e.g, up to 6th stage amplification for our example transport arcs, in contrast to two-stage amplification for a typical 4-dipole bunch compressor chicane). We also try to connect lattice optics pattern with the obtained stage gain functions by a physical interpretation. This Vlasov analys...

  19. Comparative Analysis of Carbon Plasma in Arc and RF Reactors

    SciTech Connect (OSTI)

    Todorovic-Markovic, B.; Markovic, Z.; Mohai, I.; Szepvolgyi, J.

    2004-12-01

    Results on studies of molecular spectra emitted in the initial stages of fullerene formation during the processing of graphite powder in induction RF reactor and evaporation of graphite electrodes in arc reactor are presented in this paper. It was found that C2 radicals were dominant molecular species in both plasmas. C2 radicals have an important role in the process of fullerene synthesis. The rotational-vibrational temperatures of C2 and CN species were calculated by fitting the experimental spectra to the simulated ones. The results of optical emission study of C2 radicals generated in carbon arc plasma have shown that rotational temperature of C2 species depends on carbon concentration and current intensity significantly. The optical emission study of induction RF plasma and SEM analysis of graphite powder before and after plasma treatment have shown that evaporation of the processed graphite powder depends on feed rate and composition of gas phase significantly. Based on the obtained results, it was concluded that in the plasma region CN radicals could be formed by the reaction of C2 species with atomic nitrogen at smaller loads. At larger feed rate of graphite powder, CN species were produced by surface reaction of the hot carbon particles with nitrogen atoms. The presence of nitrogen in induction RF plasma reduces the fullerene yield significantly. The fullerene yield obtained in two different reactors was: 13% in arc reactor and 4.1% in induction RF reactor. However, the fullerene production rate was higher in induction RF reactor-6.4 g/h versus 1.7 g/h in arc reactor.

  20. An interchangeable-cathode vacuum arc plasma source

    SciTech Connect (OSTI)

    Olson, David K.; Peterson, Bryan G.; Hart, Grant W.

    2010-01-15

    A simplified vacuum arc design [based on metal vapor vacuum arc (MeVVA) concepts] is employed as a plasma source for a study of a {sup 7}Be non-neutral plasma. The design includes a mechanism for interchanging the cathode source. Testing of the plasma source showed that it is capable of producing on the order of 10{sup 12} charges at confinable energies using a boron-carbide disk as the cathode target. The design is simplified from typical designs for lower energy and lower density applications by using only the trigger spark rather than the full vacuum arc in high current ion beam designs. The interchangeability of the cathode design gives the source the ability to replace only the source sample, simplifying use of radioactive materials in the plasma source. The sample can also be replaced with a completely different conductive material. The design can be easily modified for use in other plasma confinement or full MeVVA applications.

  1. RF Arc Detection in ICRH RDL Antennas by Phase Measurement

    SciTech Connect (OSTI)

    El Khaldi, M.; Vulliez, K.; Magne, R.; Bosia, G.

    2009-11-26

    A voltage breakdown in an Ion Cyclotron Resonance Heating (ICRH) system is usually detected as an abrupt change in the module of the reflection coefficient |{gamma}in| at the power source output. The same effect can be due to a large load variation. This study is carried out by constructing a electrical model for a Tore Supra ITER-like antenna (TS ILA), and to analyse how a voltage breakdown, localized in any part of the system, modifies several electrical parameters of the circuit (with respect to perfect match conditions), as detected at the location of the monitoring points. The phase difference between the reflections coefficients measured at the output of tuning network when an arc strikes in one of two Resonant double loop (RDL) sections of the ICRH TS ILA appears to be the most promising parameter to detect the arc and identify its position. It is also significantly insensitive to a load variation so an arc and edge localized modes (ELMs) can be distinguished.

  2. Arc Plasma Synthesis of Nanostructured Materials: Techniques and Innovations

    SciTech Connect (OSTI)

    Das, A. K.; Bhoraskar, S. V.; Kakati, M.; Karmakar, Soumen

    2008-10-23

    Arc plasma aided synthesis of nanostructured materials has the potential of producing complex nano phase structures in bulk quantities. Successful implementation of this potential capability to industrial scale nano generation needs establishment of a plasma parameter control regime in terms of plasma gas, flow pattern, pressure, local temperature and the plasma fields to obtain the desired nano phase structures. However, there is a need to design innovative in situ experiments for generation of an extensive database and subsequently to correlate plasma parameters to the size, shape and phase of the generated nanostructures. The present paper reviews the various approaches utilized in the field of arc plasma nanosynthesis in general and in the authors' laboratories in particular. Simple plasma diagnostics and monitoring schemes have been used in conjunction with nano materials characterization tools to explore the possibility of controlling the size, shape, yield and phase composition of the arc generated nanostructures through plasma control. Case studies related to synthesis of AlN, Al2O3, TiO2, ZrO2, ZnO), magnetic (e.g. {gamma}-Fe2O3, Fe3O4) and single elemental materials (e.g. carbon nanotubes) are presented.

  3. Vacuum Arc Ion Sources: Recent Developments and Applications

    SciTech Connect (OSTI)

    Brown, Ian; Oks, Efim

    2005-05-01

    The vacuum arc ion source has evolved over the past twenty years into a standard laboratory tool for the production of high current beams of metal ions, and is now used in a number of different embodiments at many laboratories around the world. The primary application of this kind of source has evolved to be ion implantation for material surface modification. Another important use is for injection of high current beams of heavy metal ions into the front ends of particle accelerators, and much excellent work has been carried out in recent years in optimizing the source for reliable accelerator application. The source also provides a valuable tool for the investigation of the fundamental plasma physics of vacuum arc plasma discharges. As the use of the source has grown and diversified, at the same time the ion source performance and operational characteristics have been improved in a variety of different ways also. Here we review the growth and status of vacuum arc ion sources around the world, and summarize some of the applications for which the sources have been used.

  4. Experiments with background gas in a vacuum arc centrifuge

    SciTech Connect (OSTI)

    Dallaqua, R.S.; Simpson, S.W.; Del Bosco, E.

    1996-04-01

    Since promising isotope separation results were first reported by Krishnan et al. in 1981, a range of vacuum arc centrifuge experiments have been conducted in laboratories around the world. The PCEN (Plasma CENtrifuge) vacuum arc centrifuge at the Brazilian National Institute for Space Research has been used for isotope separation studies with cathode materials of carbon and magnesium and also to investigate the performance in terms of the rotational velocity attained for different cathode materials. Here, a vacuum arc centrifuge has been operated with an initial filling gas of either argon or hydrogen for pressures ranging from 10{sup {minus}3} to 10{sup {minus}1} Pa. The angular velocity {omega} of the plasma has been determined by cross-correlating the signals from potential probes, and the electron temperature T has been deduced from Langmuir probe data. At high gas pressures and early times during the 14 ms plasma lifetime, high-frequency nonuniformities frequently observed in the vacuum discharge disappear, suggesting that the associated instability is suppressed. Under the same conditions, nonuniformities rotating with much lower angular velocities are observed in the plasma. Temperatures are reduced in the presence of the background gas, and the theoretical figure of merit for separation proportional to {omega}{sup 2}/T is increased compared to its value in the vacuum discharge for both argon and hydrogen gas fillings.

  5. Ra-Th disequilibria: Timescale of carbonatite magma formation at Oldoinyo Lengai volcano, Tanzania

    SciTech Connect (OSTI)

    Williams, R.W.; Gill, J.B.; Bruland, K.W. )

    1988-04-01

    This paper discusses geologic models dealing with the formation of carbonatites from recent lavas of the Oldoninyo Lengai volcano, Tanzania. This paper also acts as a rebutal to an earlier writing which discussed potential flaws in the collection and dating of the carbonatites. The paper goes on to provide activity ratios from different carbonatites and discussion the lack of evidence for fractional crystallization in a olivine sovite magma.

  6. Application of scientific core drilling to geothermal exploration: Platanares, Honduras and Tecuamburro Volcano, Guatemala, Central America

    SciTech Connect (OSTI)

    Goff, S.J.; Goff, F.E.; Heiken, G.H. [Los Alamos National Lab., NM (United States); Duffield, W.A. [Geological Survey, Flagstaff, AZ (United States); Janik, C.J. [Geological Survey, Menlo Park, CA (United States)

    1994-04-01

    Our efforts in Honduras and Guatemala were part of the Central America Energy Resource Project (CAERP) funded by the United States Agency for International Development (AID). Exploration core drilling operations at the Platanares, Honduras and Tecuamburro Volcano, Guatemala sites were part of a geothermal assessment for the national utility companies of these countries to locate and evaluate their geothermal resources for electrical power generation. In Honduras, country-wide assessment of all thermal areas determined that Platanares was the site with the greatest geothermal potential. In late 1986 to middle 1987, three slim core holes were drilled at Platanares to a maximum depth of 680 m and a maximum temperature of 165{degree}C. The objectives were to obtain information on the geothermal gradient, hydrothermal alterations, fracturing, and possible inflows of hydrothermal fluids. Two holes produced copious amounts of water under artesian conditions and a total of 8 MW(t) of energy. Geothermal investigations in Guatemala focused on the Tecuamburro Volcano geothermal site. The results of surface geological, volcanological, hydrogeochemical, and geophysical studies at Tecuamburro Volcano indicated a substantial shallow heat source. In early 1990 we drilled one core hole, TCB-1, to 808 m depth. The measured bottom hole temperature was 238{degree}C. Although the borehole did not flow, in-situ samples indicate the hole is completed in a vapor-zone above a probable 300{degree}C geothermal reservoir.

  7. Validation of Innovative Exploration Technologies for Newberry Volcano: Geochemistry data from 55-29 and 46-16 wells at Newberry 2012

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Jaffe, Todd

    2012-01-01

    Validation of Innovative Exploration Technologies for Newberry Volcano: Geochemistry data from 55-29 and 46-16 wells at Newberry 2012

  8. Validation of Innovative Exploration Technologies for Newberry Volcano: Geochemistry data from 55-29 and 46-16 wells at Newberry 2012

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Jaffe, Todd

    Validation of Innovative Exploration Technologies for Newberry Volcano: Geochemistry data from 55-29 and 46-16 wells at Newberry 2012

  9. QUANTIFYING PHOTOVOLTAIC FIRE DANGER REDUCTION WITH ARC-FAULT CIRCUIT INTERRUPTERS

    E-Print Network [OSTI]

    QUANTIFYING PHOTOVOLTAIC FIRE DANGER REDUCTION WITH ARC-FAULT CIRCUIT INTERRUPTERS Kenneth M, shock hazards, and cause system downtime in photovoltaic (PV) systems. The 2011 National Electrical Code

  10. Sandia Energy - PV Arc-Fault and Ground Fault Detection and Mitigation...

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

    Program Home Stationary Power Energy Conversion Efficiency Solar Energy Photovoltaics PV Systems Reliability PV Arc-Fault and Ground Fault Detection and Mitigation Program PV...

  11. Tectonic versus volcanic origin of the summit depression at Medicine Lake Volcano, California

    SciTech Connect (OSTI)

    Mark Leon Gwynn

    2010-05-01

    Medicine Lake Volcano is a Quaternary shield volcano located in a tectonically complex and active zone at the transition between the Basin and Range Province and the Cascade Range of the Pacific Province. The volcano is topped by a 7x12 km elliptical depression surrounded by a discontinuous constructional ring of basaltic to rhyolitic lava flows. This thesis explores the possibility that the depression may have formed due to regional extension (rift basin) or dextral shear (pull-apart basin) rather than through caldera collapse and examines the relationship between regional tectonics and localized volcanism. Existing data consisting of temperature and magnetotelluric surveys, alteration mineral studies, and core logging were compiled and supplemented with additional core logging, field observations, and fault striae studies in paleomagnetically oriented core samples. These results were then synthesized with regional fault data from existing maps and databases. Faulting patterns near the caldera, extension directions derived from fault striae P and T axes, and three-dimensional temperature and alteration mineral models are consistent with slip across arcuate ring faults related to magma chamber deflation during flank eruptions and/or a pyroclastic eruption at about 180 ka. These results are not consistent with a rift or pull-apart basin. Limited subsidence can be attributed to the relatively small volume of ash-flow tuff released by the only known major pyroclastic eruption and is inconsistent with the observed topographic relief. The additional relief can be explained by constructional volcanism. Striae from unoriented and oriented core, augmented by striae measurements in outcrop suggest that Walker Lane dextral shear, which can be reasonably projected from the southeast, has probably propagated into the Medicine Lake area. Most volcanic vents across Medicine Lake Volcano strike north-south, suggesting they are controlled by crustal weakness related to Basin and Range extension. Interaction of dextral shear, Basin and Range extension, and the zone of crustal weakness expressed as the Mount Shasta-Medicine Lake volcanic highland controlled the location and initiation of Medicine Lake Volcano at about 500 ka.

  12. TECTONIC VERSUS VOLCANIC ORIGIN OF THE SUMMIT DEPRESSION AT MEDICINE LAKE VOLCANO, CALIFORNIA

    SciTech Connect (OSTI)

    Mark Leon Gwynn

    2010-05-01

    Medicine Lake Volcano is a Quaternary shield volcano located in a tectonically complex and active zone at the transition between the Basin and Range Province and the Cascade Range of the Pacific Province. The volcano is topped by a 7x12 km elliptical depression surrounded by a discontinuous constructional ring of basaltic to rhyolitic lava flows. This thesis explores the possibility that the depression may have formed due to regional extension (rift basin) or dextral shear (pull-apart basin) rather than through caldera collapse and examines the relationship between regional tectonics and localized volcanism. Existing data consisting of temperature and magnetotelluric surveys, alteration mineral studies, and core logging were compiled and supplemented with additional core logging, field observations, and fault striae studies in paleomagnetically oriented core samples. These results were then synthesized with regional fault data from existing maps and databases. Faulting patterns near the caldera, extension directions derived from fault striae P and T axes, and three-dimensional temperature and alteration mineral models are consistent with slip across arcuate ring faults related to magma chamber deflation during flank eruptions and/or a pyroclastic eruption at about 180 ka. These results are not consistent with a rift or pull-apart basin. Limited subsidence can be attributed to the relatively small volume of ash-flow tuff released by the only known major pyroclastic eruption and is inconsistent with the observed topographic relief. The additional relief can be explained by constructional volcanism. Striae from unoriented and oriented core, augmented by striae measurements in outcrop suggest that Walker Lane dextral shear, which can be reasonably projected from the southeast, has probably propagated into the Medicine Lake area. Most volcanic vents across Medicine Lake Volcano strike north-south, suggesting they are controlled by crustal weakness related to Basin and Range extension. Interaction of dextral shear, Basin and Range extension, and the zone of crustal weakness expressed as the Mount Shasta-Medicine Lake volcanic highland controlled the location and initiation of Medicine Lake Volcano at about 500 ka.

  13. Formation of metal oxides by cathodic arc deposition

    SciTech Connect (OSTI)

    Anders, S.; Anders, A.; Rubin, M.; Wang, Z.; Raoux, S.; Kong, F.; Brown, I.G.

    1995-03-01

    Metal oxide thin films are of interest for a number of applications. Cathodic arc deposition, an established, industrially applied technique for formation of nitrides (e.g. TiN), can also be used for metal oxide thin film formation. A cathodic arc plasma source with desired cathode material is operated in an oxygen atmosphere, and metal oxides of various stoichiometric composition can be formed on different substrates. We report here on a series of experiments on metal oxide formation by cathodic arc deposition for different applications. Black copper oxide has been deposited on ALS components to increase the radiative heat transfer between the parts. Various metal oxides such as tungsten oxide, niobium oxide, nickel oxide and vanadium oxide have been deposited on ITO glass to form electrochromic films for window applications. Tantalum oxide films are of interest for replacing polymer electrolytes. Optical waveguide structures can be formed by refractive index variation using oxide multilayers. We have synthesized multilayers of Al{sub 2}O{sub 3}/Y{sub 2}O{sub 3}/AI{sub 2}O{sub 3}/Si as possible basic structures for passive optoelectronic integrated circuits, and Al{sub 2-x}Er{sub x}O{sub 3} thin films with a variable Er concentration which is a potential component layer for the production of active optoelectronic integrated devices such as amplifiers or lasers at a wavelength of 1.53 {mu}m. Aluminum and chromium oxide films have been deposited on a number of substrates to impart improved corrosion resistance at high temperature. Titanium sub-oxides which are electrically conductive and corrosion resistant and stable in a number of aggressive environments have been deposited on various substrates. These sub-oxides are of great interest for use in electrochemical cells.

  14. Glass Strengthening via High-Intensity Plasma-Arc Heating

    SciTech Connect (OSTI)

    Wereszczak, Andrew A; Harper, David C; Duty, Chad E; Patel, P

    2010-01-01

    The use of a high-intensity plasma-arc lamp was used to irradiate the surface of soda-lime silicate glass tiles to determine if an increase in strength could be achieved. The lamp had a power density of 3500 W/cm2, a processing area of 1 cm x 10 cm, irradiated near-infrared heating at a wavelength between 0.2 1.4 m, and was controlled to unidirectionally sweep across 50-mm-square tiles at a constant speed of 8 mm/s. Ring-on-ring (RoR) equibiaxial flexure and 4 pt uni-directional flexure testings of entire tiles were used to measure and compare failure stress distributions of treated and untreated glass. Even with non-optimized processing conditions, RoR failure stress increased by approximately 25% and the 4 pt bend failure stress increased by approximately 65%. Strengthening was due to a fire-polishing-like mechanism. The arc-lamp heat-treatment caused the location of the strength-limiting flaws in the 4-pt-bend tiles to change; namely, failure initiation occurred on the gage section surface for the treated glass whereas it occurred at a gage section edge for the untreated. Arc-lamp heat-treatment is attractive not only because it provides strengthening, but because it can (non-contact) process large amounts of glass quickly and inexpensively, and is a process that either a glass manufacturer or end-user can readily employ.

  15. Shunting arc plasma source for pure carbon ion beam

    SciTech Connect (OSTI)

    Koguchi, H.; Sakakita, H.; Kiyama, S.; Shimada, T.; Sato, Y.; Hirano, Y.

    2012-02-15

    A plasma source is developed using a coaxial shunting arc plasma gun to extract a pure carbon ion beam. The pure carbon ion beam is a new type of deposition system for diamond and other carbon materials. Our plasma device generates pure carbon plasma from solid-state carbon material without using a hydrocarbon gas such as methane gas, and the plasma does not contain any hydrogen. The ion saturation current of the discharge measured by a double probe is about 0.2 mA/mm{sup 2} at the peak of the pulse.

  16. Formation of carbon deposits from coal in an arc plasma

    SciTech Connect (OSTI)

    Wang, B.; Tian, Y.; Zhang, Y.; Zhu, S.; Lu, Y.; Zhang, Y.; Xie, K.

    2007-07-01

    The issue of deposited carbon (DC) on a reactor wall during the production of acetylene by the coal/arc plasma process is a potential obstacle for the industrialization process. The formation mechanism of DC is very difficult to reveal because the high complexity of coal and the volatile matter. Combining with quenching technique, the methane, liquid petroleum gas and benzene were employed as the model materials to roughly act as the light gas, chain and aromatic subcomponents of volatile matter, and then the reasonable formation mechanism of DC was subtly speculated accordingly.

  17. Advanced RenewableEnergy Company ARC Energy | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental Jump to:EAand DaltonSolar Energy LLCAdema TechnologiesRenewableEnergy Company ARC

  18. Neutral beam dump with cathodic arc titanium gettering

    SciTech Connect (OSTI)

    Smirnov, A.; Korepanov, S. A.; Putvinski, S.; Krivenko, A. S.; Murakhtin, S. V.; Savkin, V. Ya.

    2011-03-15

    An incomplete neutral beam capture can degrade the plasma performance in neutral beam driven plasma machines. The beam dumps mitigating the shine-through beam recycling must entrap and retain large particle loads while maintaining the beam-exposed surfaces clean of the residual impurities. The cathodic arc gettering, which provides high evaporation rate coupled with a fast time response, is a powerful and versatile technique for depositing clean getter films in vacuum. A compact neutral beam dump utilizing the titanium arc gettering was developed for a field-reversed configuration plasma sustained by 1 MW, 20-40 keV neutral hydrogen beams. The titanium evaporator features a new improved design. The beam dump is capable of handling large pulsed gas loads, has a high sorption capacity, and is robust and reliable. With the beam particle flux density of 5 x 10{sup 17} H/(cm{sup 2}s) sustained for 3-10 ms, the beam recycling coefficient, defined as twice the ratio of the hydrogen molecular flux leaving the beam dump to the incident flux of high-energy neutral atoms, is {approx}0.7. The use of the beam dump allows us to significantly reduce the recycling of the shine-through neutral beam as well as to improve the vacuum conditions in the machine.

  19. Ion velocities in a micro-cathode arc thruster

    SciTech Connect (OSTI)

    Zhuang Taisen; Shashurin, Alexey; Keidar, Michael; Beilis, Isak

    2012-06-15

    Ion velocities in the plasma jet generated by the micro-cathode arc thruster are studied by means of time-of-flight method using enhanced ion detection system (EIDS). The EIDS triggers perturbations (spikes) on arc current waveform, and the larger current in the spike generates denser plasma bunches propagating along with the mainstream plasma. The EIDS utilizes double electrostatic probes rather than single probes. The average Ti ion velocity is measured to be around 2 Multiplication-Sign 10{sup 4} m/s without a magnetic field. It was found that the application of a magnetic field does not change ion velocities in the interelectrode region while leads to ion acceleration in the free expanding plasma plume by a factor of about 2. Ion velocities of about 3.5 Multiplication-Sign 10{sup 4} m/s were detected for the magnetic field of about 300 mT at distance of about 100-200 mm from the cathode. It is proposed that plasma is accelerated due to Lorentz force. The average thrust is calculated using the ion velocity measurements and the cathode mass consumption rate, and its increase with the magnetic field is demonstrated.

  20. Material-dependent high-frequency current fluctuations of cathodic vacuum arcs: Evidence for the ecton cutoff of the fractal model

    E-Print Network [OSTI]

    Anders, Andre; Oks, Efim

    2005-01-01

    phenomena. However, spot and arc plasma phenomena are non-short coaxial cathodic arc plasma source was flange-mountedin the expanding plasma 4 , and the arc burning voltage

  1. OCEAN VOLCANO CAUGHT ON FILM Footage of a volcanic eruption nearly 1,200 metres under the sea was unveiled on 17 December at a meeting of

    E-Print Network [OSTI]

    Rosenberg, Noah

    OCEAN VOLCANO CAUGHT ON FILM Footage of a volcanic eruption nearly 1,200 metres under the sea. The high-definition film of the West Mata volcano in the western Pacific is one of the first times to raise up to US$300 million. Founded in 2005, Solyndra makes thin- film cylindrical modules for use

  2. Electrical Impedance Tomography of a Seafloor Volcano R.V. Revelle shiptime proposal submitted by David Myer, Steven Constable, and Kerry Key

    E-Print Network [OSTI]

    Key, Kerry

    Electrical Impedance Tomography of a Seafloor Volcano R.V. Revelle shiptime proposal submitted Seamount). Electrical Resistance Tomography (or ERT), also known as electrical impedance tomography will allow us to build an electrical conductivity image of a horizontal slice through the volcano at a depth

  3. SU-E-T-568: Improving Normal Brain Sparing with Increasing Number of Arc Beams for Volume Modulated Arc Beam Radiosurgery of Multiple Brain Metastases

    SciTech Connect (OSTI)

    Hossain, S; Hildebrand, K; Ahmad, S; Larson, D; Ma, L; Sahgal, A

    2014-06-01

    Purpose: Intensity modulated arc beams have been newly reported for treating multiple brain metastases. The purpose of this study was to determine the variations in the normal brain doses with increasing number of arc beams for multiple brain metastases treatments via the TrueBeam Rapidarc system (Varian Oncology, Palo Alto, CA). Methods: A patient case with 12 metastatic brain lesions previously treated on the Leksell Gamma Knife Perfexion (GK) was used for the study. All lesions and organs at risk were contoured by a senior radiation oncologist and treatment plans for a subset of 3, 6, 9 and all 12 targets were developed for the TrueBeam Rapidarc system via 3 to 7 intensity modulated arc-beams with each target covered by at least 99% of the prescribed dose of 20 Gy. The peripheral normal brain isodose volumes as well as the total beam-on time were analyzed with increasing number of arc beams for these targets. Results: All intensisty modulated arc-beam plans produced efficient treatment delivery with the beam-on time averaging 0.61.5 min per lesion at an output of 1200 MU/min. With increasing number of arc beams, the peripheral normal brain isodose volumes such as the 12-Gy isodose line enclosed normal brain tissue volumes were on average decreased by 6%, 11%, 18%, and 28% for the 3-, 6-, 9-, 12-target treatment plans respectively. The lowest normal brain isodose volumes were consistently found for the 7-arc treatment plans for all the cases. Conclusion: With nearly identical beam-on times, the peripheral normal brain dose was notably decreased when the total number of intensity modulated arc beams was increased when treating multiple brain metastases. Dr Sahgal and Dr Ma are currently serving on the board of international society of stereotactic radiosurgery.

  4. Sensitivity analysis of a dynamic model for submerged arc silicon furnaces.

    E-Print Network [OSTI]

    Foss, Bjarne A.

    Sensitivity analysis of a dynamic model for submerged arc silicon furnaces. B. F. Lund1 , B. A for a dynamic model of submerged arc silicon furnaces. The model we study, called "Simod", was developed updating a nonlinear, dynamic model of a silicon furnace. We have identified a parameter set that has

  5. Dynamic Graphics in a GIS: A Link between ARC/INFO TM and XGobi

    E-Print Network [OSTI]

    Symanzik, Jrgen

    Dynamic Graphics in a GIS: A Link between ARC/INFO TM and XGobi Jurgen Symanzik 1 , James Majure 2 GIS Support and Research Facility, Iowa State University symanzik@iastate.edu Abstract. This paper describes a link between a Geograph ical Information System (GIS), ARC/INFO TM , and an in teractive

  6. Dynamic Graphics in a GIS: A Link between ARC INFOTM and XGobi

    E-Print Network [OSTI]

    Symanzik, Jrgen

    Dynamic Graphics in a GIS: A Link between ARC INFOTM and XGobi Jurgen Symanzik1, James Majure2, Dianne Cook1, Noel Cressie1 1 Department of Statistics, Iowa State University, Ames, IA 50011, USA 2 GIS a link between a Geograph- ical Information System GIS, ARC INFOTM , and an in- teractive dynamic

  7. Small and mesoscale properties of a substorm onset auroral arc H. U. Frey,1

    E-Print Network [OSTI]

    California at Berkeley, University of

    Small and mesoscale properties of a substorm onset auroral arc H. U. Frey,1 O. Amm,2 C. C. Chaston; revised 22 June 2010; accepted 28 June 2010; published 7 October 2010. [1] We present small and mesoscale. Good agreement could be reached for the mesoscale arc properties. A qualitative analysis

  8. Arc Fault Signal Detection -Fourier Transformation vs. Wavelet Decomposition Techniques using Synthesized Data

    E-Print Network [OSTI]

    for reliable and safe system operation and is a prerequisite for widespread adoption of PV generation systems Abstract -- Arc faults are a significant reliability and safety concern for photovoltaic (PV) systems is that arc faults in the PV systems do not happen predictably, and depending on the location of the sensors

  9. Temporal evolution characteristics of an annular-mode gliding arc discharge in a vortex flow

    SciTech Connect (OSTI)

    Zhao, Tian-Liang; Liu, Jing-Lin; Li, Xiao-Song; Liu, Jin-Bao; Song, Yuan-Hong; Xu, Yong; Zhu, Ai-Min

    2014-05-15

    An annular-mode gliding arc discharge powered by a 50?Hz alternating current (ac) supply was studied in a vortex flow of dry and humid air. Its temporal evolution characteristics were investigated by electrical measurement, temporally resolved imaging, and temporally resolved optical emission spectroscopic measurements. Three discharge stages of arc-ignition, arc-gliding, and arc-extinction were clearly observed in each half-cycle of the discharge. During the arc-gliding stage, the intensity of light emission from the arc root at the cathode was remarkably higher than that at other areas. The spectral intensity of N{sub 2}(C{sup 3}?{sub u}?B{sup 3}?{sub g}) during the arc-ignition stage was much higher than that during the arc-gliding stage, which was contrary to the temporal evolutions of spectral intensities for N{sub 2}{sup +}(B{sup 2}?{sub u}{sup +}?X{sup 2}?{sub g}{sup +}) and OH(A{sup 2}?{sup +}?X{sup 2}?{sub i}). Temporally resolved vibrational and rotational temperatures of N{sub 2} were also presented and decreased with increasing the water vapor content.

  10. Shear-flow excitation mechanisms of recessed localized arc-filament plasma actuators

    E-Print Network [OSTI]

    Freund, Jonathan B.

    Shear-flow excitation mechanisms of recessed localized arc-filament plasma actuators R. R. Kleinman Received 29 April 2010; accepted 23 September 2010; published online 16 November 2010 Localized arc-filament plasma actuators, placed near the nozzle lip of a laboratory jet, have recently been demonstrated to have

  11. Method and device for reducing overpenetration at the start of plasma arc welds

    SciTech Connect (OSTI)

    Sanders, J.M.; Lehmann, J.M.; Ryan, P.M.

    2000-03-14

    A shim for improving plasma arc weld quality has ends tapered at about 25{degree} and notches at each end roughly centered over the corner between the tapered ends and main body of the shim. The improved shim allows lower starting plasma arc heat input and reduces the occurrence of sagging, or overpenetration, of the weld.

  12. Evaluation Method for Arc Fault Detection Algorithms Stephen McConnell1

    E-Print Network [OSTI]

    Laboratories, Albuquerque, New Mexico, 87185, USA Abstract -- Many methods have been proposed to detect arc for the ubiquitous use of arc fault detectors in photovoltaic arrays [1]. Without these devices, solar arrays remain in representing a host of real-world PV systems? Every solar array tied to the grid contains an electric

  13. The giant luminous arc Statistics. II. spherical lens models based on ROSAT HRI data

    E-Print Network [OSTI]

    Kohji Molikawa; Makoto Hattori; Jean-Paul Kneib; Kazuyuki Yamashita

    1999-09-10

    We present ROSAT HRI X-ray observations of all the galaxy clusters in the Le F\\`evre et al. arc survey sample in order to study the spatial distribution of the intra-cluster medium, and examine the expected number of giant luminous arcs for the sample using two spherically symmetric lens models constrained by our X-ray data.

  14. Review Article Timing of collision of the KohistanLadakh Arc with India

    E-Print Network [OSTI]

    Seno, Tetsuzo

    Review Article Timing of collision of the KohistanLadakh Arc with India and Asia: Debateiar_774 was regarded as of JurassicCretaceous age and was welded to Asia and India by Northern and Southern Sutures respectively. Formation of this arc, timings of its collisions with Asia and India, and position of collision

  15. Method and device for reducing overpenetration at the start of plasma arc welds

    DOE Patents [OSTI]

    Sanders, John M. (Jackson Township, Stark County, OH); Lehmann, John M. (Bedford County, VA); Ryan, Patrick M. (Washington Township, Stark County, OH)

    1998-01-01

    A shim for improving plasma arc weld quality has ends tapered at about 25.degree. and notches at each end roughly centered over the corner between the tapered ends and main body of the shim. The improved shim allows lower starting plasma arc heat input and reduces the occurrence of sagging, or overpenetration, of the weld.

  16. Memory-influencing intra-basolateral amygdala drug infusions modulate expression of Arc

    E-Print Network [OSTI]

    O'Toole, Alice J.

    Memory-influencing intra-basolateral amygdala drug infusions modulate expression of Arc protein processes. Infusions of the -adrenoreceptor agonist, clen- buterol, into the BLA immediately after training increased Arc protein levels in the dorsal hippocampus. Additionally, posttraining intra-BLA infusions

  17. ARC: An Integrated Admission and Rate Control Framework for CDMA Data Networks Based on

    E-Print Network [OSTI]

    Chatterjee, Mainak

    strategy set so as to maximize the utility (revenue) yet at- taining its target churn rate (the probabilityARC: An Integrated Admission and Rate Control Framework for CDMA Data Networks Based on Non this perspective, we propose an integrated admission and rate control (ARC) framework for CDMA based wire- less

  18. Visible Light Emissions during Gas Tungsten Arc Welding and Its Application to Weld

    E-Print Network [OSTI]

    Eagar, Thomas W.

    \\ Visible Light Emissions during Gas Tungsten Arc Welding and Its Application to Weld Image. EAGAR ABSTRACT. An experimental study was carried out to map the light emissions from a gas tungsten arc. The emissions were found to be dramat- ically different with different shielding gases, welding current and base

  19. Development/Plasticity/Repair A Specific Requirement of Arc/Arg3.1 for Visual

    E-Print Network [OSTI]

    Lee, Hey-Kyoung

    Development/Plasticity/Repair A Specific Requirement of Arc/Arg3.1 for Visual Experience-Induced Homeostatic Synaptic Plasticity in Mouse Primary Visual Cortex Ming Gao,1 Kenneth Sossa,1 Lihua Song,1 Lauren.OurresultsdemonstratethatArc/Arg3.1playsaselectiveroleinregulatingvisualexperience-dependent homeostatic plasticity of excitatory

  20. Enigmatic formation of the Norfolk Basin, SW Pacific: A plume influence on back-arc extension

    E-Print Network [OSTI]

    Müller, Dietmar

    Enigmatic formation of the Norfolk Basin, SW Pacific: A plume influence on back-arc extension Maria Jussieu Paris cedex 5, France (alain.mauffret@lgs.jussieu.fr) George Bernardel Geoscience Australia, Cnr] The Norfolk Basin is a small back-arc basin in the SW Pacific with an unknown age and origin for its formation

  1. The Linked ArcView 2.1TM and XGobi Environment --GIS, Dynamic Statistical Graphics, and Spatial Data

    E-Print Network [OSTI]

    Symanzik, Jrgen

    and geographic information systems. maintained within a geo- graphic information system (GIS). We developed a bidirectional link between Arc information system (GIS), ArcView 2.1TM, and an interactive dynamic graphics program in the X Window System

  2. Electrical Circuit Flashover Model of Polluted Insulators under AC Voltage Based on the Arc Root Voltage Gradient Criterion

    E-Print Network [OSTI]

    Yang, Qing

    In order to study the flashover mechanism of polluted insulators under AC voltage, a new arc propagation criterion which is based on an arc root voltage gradient is proposed. This criterion can explain the variation of the ...

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

    SciTech Connect (OSTI)

    Insepov, Zeke; Norem, Jim

    2013-01-15

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

  4. Dynamic and spectroscopic characteristics of atmospheric gliding arc in gas-liquid two-phase flow

    SciTech Connect (OSTI)

    Tu, X.; Yu, L.; Yan, J. H.; Cen, K. F.; Cheron, B. G.

    2009-11-15

    In this study, an atmospheric alternating-current gliding arc device in gas-liquid two-phase flow has been developed for the purpose of waste water degradation. The dynamic behavior of the gas-liquid gliding arc is investigated through the oscillations of electrical signals, while the spatial evolution of the arc column is analyzed by high speed photography. Different arc breakdown regimes are reported, and the restrike mode is identified as the typical fluctuation characteristic of the hybrid gliding arc in air-water mixture. Optical emission spectroscopy is employed to investigate the active species generated in the gas-liquid plasma. The axial evolution of the OH (309 nm) intensity is determined, while the rotational and vibrational temperatures of the OH are obtained by a comparison between the experimental and simulated spectra. The significant discrepancy between the rotational and translational temperatures has also been discussed.

  5. Correlation between cathode properties, burning voltage, and plasma parameters of vacuum arcs

    SciTech Connect (OSTI)

    Anders, Andre; Yotsombat, Banchob; Binder, Robert

    2001-06-15

    Burning voltages of vacuum arcs were measured for 54 cathode materials and compared with literature data. As anticipated, a correlation between the arc burning voltage and the plasma temperature was found. However, more importantly, a correlation between the cohesive energy of the cathode material and the arc burning voltage could be demonstrated. This link between a cathode material property, the cohesive energy, and a discharge property, the arc burning voltage, is essential for the operation of the vacuum arc discharge because is determines the plasma temperature. Energy balance considerations show that this {open_quotes}cohesive energy rule{close_quotes} is responsible for several other secondary relationships, such as the correlation between the mean ion charge state and the boiling temperature of the cathode. {copyright} 2001 American Institute of Physics.

  6. ArcGIS tools for streamlining habitat map data integrationArcGIS tools for streamlining habitat map data integration Paul Jessop, Chris Goldfinger, Chris RomsosPaul Jessop, Chris Goldfinger, Chris Romsos

    E-Print Network [OSTI]

    Goldfinger, Chris

    ArcGIS tools for streamlining habitat map data integrationArcGIS tools for streamlining habitat map. In addressing these problems, we are developing ArcGIS tools that streamline the regeneration of data quality navigation). The data quality tools encapsulate and automate specific processing steps used to create ranked

  7. Charge to the External Review Committee for the NSTX-U Arc Fault During the commissioning of NSTX-U for its first test plasma, an arc took place in its

    E-Print Network [OSTI]

    Princeton Plasma Physics Laboratory

    -U for its first test plasma, an arc took place in its Ohmic heating circuit inflicting significant damageCharge to the External Review Committee for the NSTX-U Arc Fault During the commissioning of NSTX questions below. 1. Technical cause: Are the causes for the arc correctly identified and understood

  8. Probe characterization of high-current driven metal plasma in a vacuum-arc rail gun

    SciTech Connect (OSTI)

    Vijayan, T.; Roychowdhury, P.; Venkatramani, N.

    2004-10-15

    The characteristics of metal plasma launched by high-current electric arc in a vacuum-arc rail gun are determined by employing electrical and magnetic probes. These measurements are validated by results from theoretical simulations. The arc coupled nonlinear circuit equations are solved simultaneously with the Newtonian arc motion and revealed the undercritically damped behavior of the arc current identical to the arc-current signal recorded by the Rogowski magnetic probe. Similarly the arc velocity and displacement derived from the signatures of B-dot probes are shown to concur closely with the results of JxB propulsion from simulation. The heating of plasma is formulated in a three-electron population regime with direct arc energy coupling through magnetohydrodynamic, ion-acoustic, Coulomb, and neutral interactions. This results in high temperature (T{sub e}) of hundreds of eV in the arc as revealed by the simulation. Hence T{sub e} of the rapidly cooling and equilibrating plasma that emerged from the muzzle is high around 80-90 eV, which is confirmed by Langmuir electric probe measurements. Density n{sub e} of this metal plasma is shown to be in the range 4x10{sup 21}-6x10{sup 21} m{sup -3} and includes multiple ion charge states. The exit velocity of the plasma measured by a pair of Langmuir probes is close to 2.2x10{sup 6} cm/s and matched well with the arc velocity determined by the B-dot probes and the results from simulation.

  9. A comparison of the marginal adaptation of cathode-arc vapor-deposited titanium and cast base metal copings.

    E-Print Network [OSTI]

    Wu, Jean C; Lai, Li-Chung; Sheets, Cherilyn G; Earthman, James; Newcomb, Robert

    2011-01-01

    thick, dark titanium oxide layer. The new cathode-arc vaporcolor of the titanium oxide layer resulted in compromised

  10. Study of JET Soft Housekeeping Waste Volume Reduction by Plasma Arc Centrifuge and Gasification in Countercurrent Regime Methods

    E-Print Network [OSTI]

    Study of JET Soft Housekeeping Waste Volume Reduction by Plasma Arc Centrifuge and Gasification in Countercurrent Regime Methods

  11. Dynamic Graphics in a GIS: A Bidirectional Link between ArcView 2.1TM and XGobi | An Update

    E-Print Network [OSTI]

    Symanzik, Jrgen

    Dynamic Graphics in a GIS: A Bidirectional Link between ArcView 2.1TM and XGobi | An Update J a Geographic Information System GIS, ArcView 2.1TM, and an interactive dynamic graphics program, XGobi. Arc to the integrationof a Geographic InformationSystem GIS,to be used for the display of spatial locations and concomitant

  12. Dynamic Graphics in a GIS: A Bidirectional Link between ArcView 2.1 TM and XGobi ---An Update

    E-Print Network [OSTI]

    Symanzik, Jrgen

    Dynamic Graphics in a GIS: A Bidirectional Link between ArcView 2.1 TM and XGobi --- An Update J a Geographic Information System (GIS), ArcView 2.1 TM , and an interactive dynamic graphics program, XGobi. Arc (GIS), to be used for the display of spatial locations and concomitant geographic variables

  13. ARC Photovoltaics Centre of Excellence 2009 A n n u a l R e p o r t

    E-Print Network [OSTI]

    New South Wales, University of

    ARC Photovoltaics Centre of Excellence 2009 A n n u a l R e p o r t #12;ARC Photovoltaics Centre of Excellence #12;ARC Photovoltaics Centre of Excellence 1 2009 Annual Report Contents Section______________________________________________________134 8. Publications____________________________________________________________136 #12;PHOTOVOLTAICS

  14. Mechanism of surface modification in the plasma-surface interaction in electrical arcs CERN, CH-1211 Genve 23, Switzerland

    E-Print Network [OSTI]

    Nordlund, Kai

    Mechanism of surface modification in the plasma-surface interaction in electrical arcs H. Timko received 22 February 2010; published 25 May 2010 Electrical sparks and arcs are plasma discharges the given conditions in the plasma sheath to kiloelectron volt energies, on surfaces. The flux in arcs is so

  15. Dilution Control in Gas-Tungsten-Arc Welds Involving Superaustenitic Stainless Steels and Nickel-Based Alloys

    E-Print Network [OSTI]

    DuPont, John N.

    ) were produced by varying the independent welding parameters of arc power and volumetric filler and decreasing arc power. These effects are quantitatively interpreted based on a previously proposed processing be correlated exclusively to the ratio of the volumetric filler-metal feed rate (Vfm) to arc power (VI), i

  16. ELLIPTIC ARC VECTORIZATION FOR 3D PIE CHART RECOGNITION Weihua Huang, Chew Lim Tan and Wee Kheng Leow

    E-Print Network [OSTI]

    Leow, Wee Kheng

    ELLIPTIC ARC VECTORIZATION FOR 3D PIE CHART RECOGNITION Weihua Huang, Chew Lim Tan and Wee Kheng, we present a novel approach to vectorize elliptic arcs for 3D pie chart recognition and data elliptic arcs are the key components in the 3D pie charts that allow us to determine the chart type

  17. Inferring crustal structure in the Aleutian island arc from a sparse wide-angle seismic data set

    E-Print Network [OSTI]

    Shillington, Donna J.

    in the Aleutian islands shed a new light on island arc systems, and the role that magmatic arcs may play G 3 G 3Inferring crustal structure in the Aleutian island arc from a sparse wide-angle seismic data set inversion with static corrections for island stations reduces the data variance of a 1-D starting model

  18. Gas-tungsten arc welding of aluminum alloys

    DOE Patents [OSTI]

    Frye, L.D.

    1982-03-25

    The present invention is directed to a gas-tungsten arc welding method for joining together structures formed of aluminum alloy with these structures disposed contiguously to a heat-damagable substrate of a metal dissimilar to the aluminum alloy. The method of the present invention is practiced by diamond machining the fay surfaces of the aluminum alloy structures to profice a mirror finish thereon having a surface roughness in the order of about one microinch. The fay surface are aligned and heated sufficiently by the tungsten electrode to fuse the aluminum alloy continguous to the fay surfaces to effect the weld joint. The heat input used to provide an oxide-free weld is significantly less than that required if the fay surfaces were prepared by using conventional chemical and mechanical practices.

  19. Method of operating a centrifugal plasma arc furnace

    DOE Patents [OSTI]

    Kujawa, S.T.; Battleson, D.M.; Rademacher, E.L. Jr.; Cashell, P.V.; Filius, K.D.; Flannery, P.A.; Whitworth, C.G.

    1998-03-24

    A centrifugal plasma arc furnace is used to vitrify contaminated soils and other waste materials. An assessment of the characteristics of the waste is performed prior to introducing the waste into the furnace. Based on the assessment, a predetermined amount of iron is added to each batch of waste. The waste is melted in an oxidizing atmosphere into a slag. The added iron is oxidized into Fe{sub 3}O{sub 4}. Time of exposure to oxygen is controlled so that the iron does not oxidize into Fe{sub 2}O{sub 3}. Slag in the furnace remains relatively non-viscous and consequently it pours out of the furnace readily. Cooled and solidified slag produced by the furnace is very resistant to groundwater leaching. The slag can be safely buried in the earth without fear of contaminating groundwater. 3 figs.

  20. Method of operating a centrifugal plasma arc furnace

    DOE Patents [OSTI]

    Kujawa, Stephan T. (Butte, MT); Battleson, Daniel M. (Butte, MT); Rademacher, Jr., Edward L. (Butte, MT); Cashell, Patrick V. (Butte, MT); Filius, Krag D. (Butte, MT); Flannery, Philip A. (Ramsey, MT); Whitworth, Clarence G. (Butte, MT)

    1998-01-01

    A centrifugal plasma arc furnace is used to vitrify contaminated soils and other waste materials. An assessment of the characteristics of the waste is performed prior to introducing the waste into the furnace. Based on the assessment, a predetermined amount of iron is added to each batch of waste. The waste is melted in an oxidizing atmosphere into a slag. The added iron is oxidized into Fe.sub.3 O.sub.4. Time of exposure to oxygen is controlled so that the iron does not oxidize into Fe.sub.2 O.sub.3. Slag in the furnace remains relatively non-viscous and consequently it pours out of the furnace readily. Cooled and solidified slag produced by the furnace is very resistant to groundwater leaching. The slag can be safely buried in the earth without fear of contaminating groundwater.

  1. Arc plasma simulation of the KAERI large ion source

    SciTech Connect (OSTI)

    In, S. R.; Jeong, S. H.; Kim, T. S.

    2008-02-15

    The KAERI large ion source, developed for the KSTAR NBI system, recently produced ion beams of 100 keV, 50 A levels in the first half campaign of 2007. These results seem to be the best performance of the present ion source at a maximum available input power of 145 kW. A slight improvement in the ion source is certainly necessary to attain the final goal of an 8 MW ion beam. Firstly, the experimental results were analyzed to differentiate the cause and effect for the insufficient beam currents. Secondly, a zero dimensional simulation was carried out on the ion source plasma to identify which factors control the arc plasma and to find out what improvements can be expected.

  2. Quantitative characterization of arc discharge as vacuum interface

    SciTech Connect (OSTI)

    Huang, S.; Zhu, K.; Lu, Y. R.; Wang, S. Z.; Hershcovitch, A.; Yang, L.; Zhang, X. Y.

    2014-12-19

    An arc discharge with channel diameters of 3 mm and 6 mm and lengths between 30mm and 60mm was experimentally investigated for its potential to function as plasma window, i.e., interface vacuum regions of different pressures. In this study, electron temperature of the plasma channel measured spectroscopically varied in the range of 7000K to 15000K, increasing with discharge current while decreasing with gas flow rate. The plasma window had a slightly positive I-V characteristics over the whole range of investigated current 30A70 A. Measurements of pressure separation capability, which were determined by input current, gas flow rate, discharge channel diameter, and length, were well explained by viscosity effect and thermal-block effect. The experimental results of global parameters including temperature, gas flow rate, and voltage had a good agreement with the simulation results calculated by an axis-symmetry Fluent-based magneto-hydrodynamic model.

  3. Quantitative characterization of arc discharge as vacuum interface

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

    Huang, S.; Zhu, K.; Lu, Y. R.; Wang, S. Z.; Hershcovitch, A.; Yang, L.; Zhang, X. Y.

    2014-12-19

    An arc discharge with channel diameters of 3 mm and 6 mm and lengths between 30mm and 60mm was experimentally investigated for its potential to function as plasma window, i.e., interface vacuum regions of different pressures. In this study, electron temperature of the plasma channel measured spectroscopically varied in the range of 7000K to 15000K, increasing with discharge current while decreasing with gas flow rate. The plasma window had a slightly positive I-V characteristics over the whole range of investigated current 30A70 A. Measurements of pressure separation capability, which were determined by input current, gas flow rate, discharge channel diameter,moreand length, were well explained by viscosity effect and thermal-block effect. The experimental results of global parameters including temperature, gas flow rate, and voltage had a good agreement with the simulation results calculated by an axis-symmetry Fluent-based magneto-hydrodynamic model.less

  4. Evolution of Holographic Fermi Arcs from a Mott Insulator

    E-Print Network [OSTI]

    Garrett Vanacore; Srinidhi T. Ramamurthy; Philip W. Phillips

    2015-08-10

    We study fermions in an electrically-probed and asymptotically anti-de Sitter Schwarzschild spacetime which interact via a novel chiral symmetry-preserving interaction. Computing the dual fermion two-point correlator, we show that this bulk interaction anisotropically gaps Fermi surfaces of the boundary spectrum. Consequently, the interaction we devise provides a holographic model for Fermi arcs seen ubiquitously in the pseudogap regime of the cuprates. Our interaction is a modification of the chiral symmetry-breaking Pauli coupling, which has previously been proposed as the holographic realization of Mott physics. The onset of Mott insulation and pseudogap physics are respectively discussed in the context of bulk chiral and boundary parity symmetry breaking, and the Mott transition is interpreted as a deconfinement transition of non-Fermi liquid excitations.

  5. Evolution of Holographic Fermi Arcs from a Mott Insulator

    E-Print Network [OSTI]

    Vanacore, Garrett; Phillips, Philip W

    2015-01-01

    We study fermions in an electrically-probed and asymptotically anti-de Sitter Schwarzschild spacetime which interact via a novel chiral symmetry-preserving interaction. Computing the dual fermion two-point correlator, we show that this bulk interaction anisotropically gaps Fermi surfaces of the boundary spectrum. Consequently, the interaction we devise provides a holographic model for Fermi arcs seen ubiquitously in the pseudogap regime of the cuprates. Our interaction is a modification of the chiral symmetry-breaking Pauli coupling, which has previously been proposed as the holographic realization of Mott physics. The onset of Mott insulation and pseudogap physics are respectively discussed in the context of bulk chiral and boundary parity symmetry breaking, and the Mott transition is interpreted as a deconfinement transition of non-Fermi liquid excitations.

  6. Results of geothermal gradient core hole TCB-1, Tecuamburro volcano geothermal site, Guatemala, Central America

    SciTech Connect (OSTI)

    Adams, A.I.; Chipera, S.; Counce, D.; Gardner, J.; Goff, S.; Goff, F.; Heiken, G.; Laughlin, A.W.; Musgrave, J.; Trujillo, P.E. Jr. (Los Alamos National Lab., NM (United States)); Aycinena, S.; Martinelli, L. (Swissboring Overseas Corp. Ltd., Guatemala City (Guatemala)); Castaneda, O.; Revolorio, M.; Roldan, A. (Unidad de Desarrollo Geotermico, Guatemala City (Guatemala). Inst. Nacional de Electrificacion); D

    1992-02-01

    Results of geological, volcanological, hydrogeochemical, and geophysical field studies conducted in 1988 and 1989 at the Tecuamburro volcano geothermal site in Guatemala indicated that there is a substantial shallow heat source beneath the area of youngest volcanism. To obtain information on subsurface temperatures and temperature gradients, stratigraphy, hydrothermal alteration, fracturing, and possible inflows of hydrothermal fluids, a geothermal gradient core hole (TCB-1) was drilled to 808 m low on the northern flank of the Tecuamburro volcano Complex, 300 km south of a 300-m-diameter phreatic crater, Laguna Ixpaco, dated at 2,910 years. Gases from acid-sulfate springs near Laguna Ixpaco consistently yield maximum estimated subsurface temperatures of 250--300{degrees}C. The temperature versus depth curve from TCB-1 does not show isothermal conditions and the calculated thermal gradients from 500--800 m is 230{degrees}C/km. Bottom hole temperature is 238{degrees}C. Calculated heat flow values are nearly 9 heat flow units (HFU). The integration of results from the TCB-1 gradient core hole with results from field studies provides strong evidence that the Tecuamburro area holds great promise for containing a commercial geothermal resource.

  7. Characterization of an atmospheric double arc argon-nitrogen plasma source

    SciTech Connect (OSTI)

    Tu, X.; Cheron, B. G.; Yan, J. H.; Yu, L.; Cen, K. F.

    2008-05-15

    In the framework of studies devoted to hazardous waste destruction, an original dc double anode plasma torch has been designed and tested, which produces an elongated, weak fluctuation and reproducible plasma jet at atmospheric pressure. The arc instabilities and dynamic behavior of the double arc argon-nitrogen plasma jet are investigated through the oscillations of electrical signals by combined means of fast Fourier transform and Wigner distribution. In our experiment, the restrike mode is identified as the typical fluctuation behavior in an argon-nitrogen plasma jet. The Fourier spectra and Wigner distributions exhibit two characteristic frequencies of 150 Hz and 4.1 kHz, which reveals that the nature of fluctuations in the double arc argon-nitrogen plasma can be ascribed to the undulation of the power supply and both arc roots motion on the anode channels. In addition, the microscopic properties of the plasma jet inside and outside the arc chamber are investigated by means of optical emission spectroscopy, which yields excitation, electronic, rotational, and vibrational temperatures, as well as the electron number density. The results allow us to examine the validity criteria of a local thermodynamic equilibrium (LTE) state in the plasma arc. The measured electron densities are in good agreement with those calculated from the LTE model, which indicates that the atmospheric double arc argon-nitrogen plasma in the core region is close to the LTE state under our experimental conditions.

  8. Current constriction of high-current vacuum arc in vacuum interrupters

    SciTech Connect (OSTI)

    Wang Lijun; Jia Shenli; Zhang Ling; Yang Dingge; Shi Zongqian; Gentils, Francois; Jusselin, Benoit

    2008-03-15

    Compared with previous paper [L. Wang et al., J. Appl. Phys. 100, 113304 (2006)], higher-current vacuum arc is simulated and analyzed based on magnetohydrodynamics model, and current constriction phenomenon in arc column is mainly paid attention to and analyzed in this paper. According to simulation results, it can be found that significant current constriction only appears near anode regions for lower-current vacuum arc. However, with the increase of arc current, current constriction also appears near the cathode side, and with the further increase of arc current, current constriction near the cathode side can become more significant than that near the anode side. The current constriction near the cathode side can be mainly caused by very high current level. The increase of axial magnetic field (AMF) strength will inhibit current constriction in the whole arc column. For influence of AMF distribution, saddle-shaped distributed AMF can more efficiently inhibit current constriction of arc column than bell-shaped AMF. The phenomenon of current constriction near the cathode side has also been found by many experiments, which also can verify the correctness of simulation results.

  9. Creating dynamic equivalent PV circuit models with impedance spectroscopy for arc-fault modeling.

    SciTech Connect (OSTI)

    Johnson, Jay Dean; Kuszmaul, Scott S.; Strauch, Jason E.; Schoenwald, David Alan

    2011-06-01

    Article 690.11 in the 2011 National Electrical Code{reg_sign} (NEC{reg_sign}) requires new photovoltaic (PV) systems on or penetrating a building to include a listed arc fault protection device. Currently there is little experimental or empirical research into the behavior of the arcing frequencies through PV components despite the potential for modules and other PV components to filter or attenuate arcing signatures that could render the arc detector ineffective. To model AC arcing signal propagation along PV strings, the well-studied DC diode models were found to inadequately capture the behavior of high frequency arcing signals. Instead dynamic equivalent circuit models of PV modules were required to describe the impedance for alternating currents in modules. The nonlinearities present in PV cells resulting from irradiance, temperature, frequency, and bias voltage variations make modeling these systems challenging. Linearized dynamic equivalent circuits were created for multiple PV module manufacturers and module technologies. The equivalent resistances and capacitances for the modules were determined using impedance spectroscopy with no bias voltage and no irradiance. The equivalent circuit model was employed to evaluate modules having irradiance conditions that could not be measured directly with the instrumentation. Although there was a wide range of circuit component values, the complex impedance model does not predict filtering of arc fault frequencies in PV strings for any irradiance level. Experimental results with no irradiance agree with the model and show nearly no attenuation for 1 Hz to 100 kHz input frequencies.

  10. Matched Optics of Muon RLA and Non-Scaling FFAG ARCS

    SciTech Connect (OSTI)

    V.S. Morozov, S.A. Bogacz, Y. Roblin, K.B. Beard, D. Trbojevic

    2011-03-01

    Recirculating Linear Accelerators (RLA) are an efficient way of accelerating short-lived muons to multi-GeV energies required for Neutrino Factories and TeV energies required for Muon Colliders. To reduce the number of required return arcs, we employ a Non-Scaling Fixed-Field Alternating-Gradient (NS-FFAG) arc lattice design. We present a complete linear optics design of a muon RLA with two-pass linear NS-FFAG droplet return arcs. The arcs are composed of symmetric cells with each cell designed using combined function magnets with dipole and quadrupole magnetic field components so that the cell is achromatic and has zero initial and final periodic orbit offsets for both passes energies. Matching to the linac is accomplished by adjusting linac quadrupole strengths so that the linac optics on each pass is matched to the arc optics. We adjust the difference of the path lengths and therefore of the times of flight of the two momenta in each arc to ensure proper synchronization with the linac. We investigate the dynamic aperture and momentum acceptance of the arcs.

  11. Arc discharge regulation of a megawatt hot cathode bucket ion source for the experimental advanced superconducting tokamak neutral beam injector

    SciTech Connect (OSTI)

    Xie Yahong; Hu Chundong; Liu Sheng; Jiang Caichao; Li Jun; Liang Lizhen; Collaboration: NBI Team

    2012-01-15

    Arc discharge of a hot cathode bucket ion source tends to be unstable what attributes to the filament self-heating and energetic electrons backstreaming from the accelerator. A regulation method, which based on the ion density measurement by a Langmuir probe, is employed for stable arc discharge operation and long pulse ion beam generation. Long pulse arc discharge of 100 s is obtained based on this regulation method of arc power. It establishes a foundation for the long pulse arc discharge of a megawatt ion source, which will be utilized a high power neutral beam injection device.

  12. Modeling And Measurements Of The Arc Plasma In A Mixture Of Gases

    SciTech Connect (OSTI)

    Pawelec, E.; KsiaPzek, I.

    2006-01-15

    Radial distributions of Ar mass fractions and temperatures in plasmas produced in a wall-stabilized arc have been calculated. Modeling have been performed for many different mixtures of Ar+N2 and three different arc currents. The obtained results show that the radial distributions of Ar mass fractions strongly depend on the chemical composition of the plasma. In plasmas containing large amount of Ar the distributions have local minima at the arc axis (in high temperature plasma regions), whereas in plasmas consisting mainly of nitrogen the distributions reveal maxima on the discharge axis. Those features seem to be connected with the dissociation of the nitrogen.

  13. The nature of fluctuations in a double arc argon-nitrogen plasma jet

    SciTech Connect (OSTI)

    Tu Xin; Yan Jianhua; Yu Liang; Cen, Kefa; Cheron, Bruno

    2007-09-24

    The dynamic behavior of the double arc argon-nitrogen plasma jet is investigated by combined means of the fast Fourier transform, correlation function, and Wigner distribution. The restrike mode is identified as the fluctuation behavior in an argon-nitrogen plasma jet. The Fourier spectra exhibit two characteristic frequencies of 150 Hz and 4.1 kHz, which indicates that the nature of fluctuations in the double arc argon-nitrogen plasma can be ascribed to the power supply undulation and both arc roots motion on the anode channels. It is further found that the double anode torch could inhibit and reduce the restrike phenomenon.

  14. Arc Detection and Interlock Module for the PEP II Low Level RF System

    SciTech Connect (OSTI)

    Tighe, R.; /SLAC

    2011-08-31

    A new arc detection and interlock generating module for the SLAC PEP-II low-level RF VXI-based system has been developed. The system is required to turn off the RF drive and high voltage power supply in the event of arcing in the cavity windows, klystron window, or circulator. Infrared photodiodes receive arc signals through radiation resistant optical fibers. Gain and bandwidth are selectable for each channel to allow tailoring response. The module also responds to interlock requests from other modules in the VXI system and communicates with the programmable logic controller (PLC) responsible for much of the low-level RF system's interlock functionality.

  15. 2 Tilt recorded by a portable broadband seismograph: The 2003 3 eruption of Anatahan Volcano, Mariana Islands

    E-Print Network [OSTI]

    are highly sensitive to tilt, suggesting that commonly 14 deployed portable broadband seismic sensors may was recorded by a Strekheisen 19 STS-2 seismograph deployed in an underground insulated 20 chamber 7 km west volcano- 24 tectonic (VT) seismicity and is one hour prior to the 25 eruption time estimated

  16. Deep-slab fluids fuel extremophilic Archaea on a Mariana forearc serpentinite mud volcano: Ocean Drilling Program

    E-Print Network [OSTI]

    Moyer, Craig

    Deep-slab fluids fuel extremophilic Archaea on a Mariana forearc serpentinite mud volcano: Ocean, M. J., S. C. Komor, P. Fryer, and C. L. Moyer, Deep-slab fluids fuel extremophilic Archaea.5, made up overwhelmingly of Archaea, is oxidizing methane from the ascending fluid to carbonate ion

  17. Evidence for static stress changes triggering the 1999 eruption of Cerro Negro Volcano, Nicaragua and regional aftershock sequences

    E-Print Network [OSTI]

    Connor, Charles

    Evidence for static stress changes triggering the 1999 eruption of Cerro Negro Volcano, Nicaragua explain this coupling through static stress changes following three Mw 5.2 earthquakes. We use focal seismicity and volcanism, and suggests that these small changes in static stress can trigger subsequent

  18. Analyses of in-situ airborne volcanic ash from the February 2000 eruption of Hekla Volcano, Iceland

    E-Print Network [OSTI]

    Ma, Chi

    Analyses of in-situ airborne volcanic ash from the February 2000 eruption of Hekla Volcano, Iceland-8 NASA research aircraft inadvertently flew into an airborne volcanic ash plume from the 26 February spectrophotometer analyses. These analyses confirm that the DC-8 encountered airborne volcanic ash from Hekla

  19. Water content of 1997 vulcanian pumices at Soufriere Hills Volcano (Montserrat) and implications on pre-eruptive conduit conditions

    E-Print Network [OSTI]

    Paris-Sud XI, Universit de

    Water content of 1997 vulcanian pumices at Soufriere Hills Volcano (Montserrat) and implications of the eruptive products. We used quantitative analysis of water content in residual glasses (matrix glass. To better link water content to structural level, we performed new water solubility experiments at low

  20. Internal structure of the western flank of the Cumbre Vieja volcano, La Palma, Canary Islands, from land

    E-Print Network [OSTI]

    Jones, Alan G.

    Palma, Canary Islands, from land magnetotelluric imaging X. Garcia1,2 and A. G. Jones1 Received 9 March on the island of La Palma (Canary Islands) provides an ideal setting to address fundamental questions about (2010), Internal structure of the western flank of the Cumbre Vieja volcano, La Palma, Canary Islands

  1. Iceland is a country of breathtaking natural beauty, geothermal activity and volcanoes that, as we all know by

    E-Print Network [OSTI]

    Tradacete, Pedro

    Iceland is a country of breathtaking natural beauty, geothermal activity and volcanoes that, as we. Después de la presentación habrá un pequeño refrigerio en la Sala de reuniones. Iceland: Glaciers Reykjavik University, Iceland SEMINARIO Departamento de Sistemas Informáticos y Computación Facultad de

  2. Self-potential, soil CO2 flux, and temperature on Masaya volcano, J. L. Lewicki,1,2

    E-Print Network [OSTI]

    Connor, Charles

    , soil CO2 flux, and temperature may be a useful tool to monitor intrusive activity. INDEX TERMS: 0925 monitoring. We present soil CO2 flux, temperature, and SP data measured concurrently on the flanks of MasayaSelf-potential, soil CO2 flux, and temperature on Masaya volcano, Nicaragua J. L. Lewicki,1,2 C

  3. SciSat AM: Stereo 03: Dosmetric evaluation of single versus multi-arc VMAT for lung SBRT

    SciTech Connect (OSTI)

    Karan, T; Taremi, M; Comsa, D; Allibhai, Z; Ryan, M; Le, K

    2014-08-15

    Five non-small cell lung cancer patients previously treated with stereotactic body radiation therapy using the VMAT (volumetric modulated arc therapy) technique were selected for this retrospective study. Plans were re-optimized using Pinnacle treatment planning system (v9.0, Philips Medical), with the basis for comparison a two-arc plan involving a 360 arc in addition to a 90 arc with a couch kick. Additionally a single 360 arc was optimized for comparison, as well as a partial arc covering ?230, avoiding the contralateral lung. All plans met target coverage criteria as dictated by RTOG0236. Plans were evaluated based on conformity, sparing of organs at risk and practical considerations of delivery. Conformity was best in the two-arc plan; however the decrease seen in one- and partial arc plans was not statistically significant as tested by the Wilcoxon rank sum test. The partial-arc plan resulted in the lowest esophagus and trachea dose and the highest heart dose, however none of the plans exceeded organ at risk tolerances for lung SBRT. Partial arcs resulted in plans with slightly cooler dose distributions, a decrease in low dose spillage and an overall lower mean lung dose. The decrease in treatment time was on average 36 and 40 seconds for single and partial arcs, respectively, with partial arcs requiring the lowest number of MUs. The slight decrease in conformity seen in one-arc plans is offset by an increase in efficiency (optimization and treatment time, MUs) making the implementation of a single or partial-arc treatment technique clinically desirable.

  4. Characterizing Fire Danger from Low-Power Photovoltaic Arc-Faults Kenneth M. Armijo, Jay Johnson, Michael Hibbs and Armando Fresquez

    E-Print Network [OSTI]

    capacity of photovoltaic systems continues to grow and age, the number of arc-faults in PV systemsCharacterizing Fire Danger from Low-Power Photovoltaic Arc-Faults Kenneth M. Armijo, Jay Johnson -- While arc-faults are rare in photovoltaic installations, more than a dozen documented arc-faults have

  5. Innovative Energy Conservation Through Scrao Pre-heating in an Electric Arc Furnace

    E-Print Network [OSTI]

    Dicion, A.

    2013-01-01

    This paper will present an innovative energy conservation technology for scrap pre-heating in an Electric Arc Furnace that is being implemented in an industrial facility in Ontario. The objective of the paper is to examine the electrical...

  6. The evolution of ion charge states in cathodic vacuum arc plasmas: a review

    SciTech Connect (OSTI)

    Anders, Andre

    2011-12-18

    Cathodic vacuum arc plasmas are known to contain multiply charged ions. 20 years after Pressure Ionization: its role in metal vapour vacuum arc plasmas and ion sources appeared in vol. 1 of Plasma Sources Science and Technology, it is a great opportunity to re-visit the issue of pressure ionization, a non-ideal plasma effect, and put it in perspective to the many other factors that influence observable charge state distributions, such as the role of the cathode material, the path in the density-temperature phase diagram, the noise in vacuum arc plasma as described by a fractal model approach, the effects of external magnetic fields and charge exchange collisions with neutrals. A much more complex image of the vacuum arc plasma emerges putting decades of experimentation and modeling in perspective.

  7. Application of electrostatic Langmuir probe to atmospheric arc plasmas producing nanostructures

    SciTech Connect (OSTI)

    Shashurin, A.; Li, J.; Zhuang, T.; Keidar, M.; Beilis, I. I.

    2011-07-15

    The temporal evolution of a high pressure He arc producing nanotubes was considered and the Langmuir probe technique was applied for plasma parameter measurements. Two modes of arc were observed: cathodic arc where discharge is supported by erosion of cathode material and anodic arc which is supported by ablation of the anode packed with carbon and metallic catalysts in which carbon nanotubes are synthesized. Voltage-current (V-I) characteristics of single probes were measured and unusually low ratio of saturation current on positively biased probe to that on negatively biased of about 1-4 was observed. This effect was explained by increase of measured current at the negatively biased probe above the level of ion saturation current due to secondary electron emission from the probe surface. Since utilization of standard collisionless approach to determine plasma parameters from the measured V-I characteristic is not correct, the electron saturation current was used to estimate the plasma density.

  8. Controlling electrode gap during vacuum arc remelting at low melting current

    DOE Patents [OSTI]

    Williamson, R.L.; Zanner, F.J.; Grose, S.M.

    1997-04-15

    An apparatus and method are disclosed for controlling electrode gap in a vacuum arc remelting furnace, particularly at low melting currents. Spectrographic analysis is performed of the metal vapor plasma, from which estimates of electrode gap are derived. 5 figs.

  9. Controlling electrode gap during vacuum arc remelting at low melting current

    DOE Patents [OSTI]

    Williamson, Rodney L. (Albuquerque, NM); Zanner, Frank J. (Sandia Park, NM); Grose, Stephen M. (Glenwood, WV)

    1997-01-01

    An apparatus and method for controlling electrode gap in a vacuum arc remelting furnace, particularly at low melting currents. Spectrographic analysis is performed of the metal vapor plasma, from which estimates of electrode gap are derived.

  10. Computational study of flow dynamics from a dc arc plasma jet

    E-Print Network [OSTI]

    Trelles, Juan Pablo

    2013-01-01

    Plasma jets produced by direct-current (DC) non-transferred arc plasma torches, at the core of technologies ranging from spray coating to pyrolysis, present intricate dynamics due to the coupled interaction of fluid flow, thermal, and electromagnetic phenomena. The flow dynamics from an arc discharge plasma jet are investigated using time-dependent three-dimensional simulations encompassing the dynamics of the arc inside the torch, the evolution of the jet through the discharge environment, and the subsequent impingement of the jet over a flat substrate. The plasma is described by a chemical equilibrium and thermodynamic nonequilibrium (two-temperature) model. The numerical formulation of the physical model is based on a monolithic and fully-coupled treatment of the fluid and electromagnetic equations using a Variational Multiscale Finite Element Method. Simulation results uncover distinct aspects of the flow dynamics, including the jet forcing due to the movement of the electric arc, the prevalence of deviat...

  11. Improving the System Life of Basic Oxygen and Electric Arc Furnace Hoods, Roofs, and Side Vents

    Broader source: Energy.gov [DOE]

    This factsheet describes the benefits of a high-performance aluminum bronze alloy to basic oxygen furnace and electric arc furnace components such as hoods, roofs, and side vents.

  12. How do I display the Map of Wind Farms csv coordinates in ArcMap...

    Open Energy Info (EERE)

    I display the Map of Wind Farms csv coordinates in ArcMap software? Home > Groups > Geospatial I downloaded the Map of Wind Farms data as a .csv from http:en.openei.orgwiki...

  13. Exhaust-gas measurements from NASAs HYMETS arc jet.

    SciTech Connect (OSTI)

    Miller, Paul Albert

    2010-11-01

    Arc-jet wind tunnels produce conditions simulating high-altitude hypersonic flight such as occurs upon entry of space craft into planetary atmospheres. They have traditionally been used to study flight in Earth's atmosphere, which consists mostly of nitrogen and oxygen. NASA is presently using arc jets to study entry into Mars' atmosphere, which consists of carbon dioxide and nitrogen. In both cases, a wide variety of chemical reactions take place among the gas constituents and with test articles placed in the flow. In support of those studies, we made measurements using a residual gas analyzer (RGA) that sampled the exhaust stream of a NASA arc jet. The experiments were conducted at the HYMETS arc jet (Hypersonic Materials Environmental Test System) located at the NASA Langley Research Center, Hampton, VA. This report describes our RGA measurements, which are intended to be used for model validation in combination with similar measurements on other systems.

  14. Novel Direct Steelmaking by Combining Microwave, Electric Arc, and Exothermal Heating Technologies

    Broader source: Energy.gov [DOE]

    This factsheet describes a project to develop direct steelmaking through the combination of microwave, electric arc, and exothermal heating, a process which is meant to eliminate traditional, intermediate steelmaking steps.

  15. Volatilization and redox testing in a DC arc melter: FY-93 and FY-94

    SciTech Connect (OSTI)

    Grandy, J.D.; Sears, J.W.; Soelberg, N.R.; Reimann, G.A.; McIlwain, M.E.

    1996-07-01

    The purpose of these experiments was to study the dissolution, retention, volatilization, and trapping of transuranic radionuclide elements (TRUs), mixed fission and activation products, and high vapor pressure metals (HVPMS) during processing in a high temperature arc furnace. In all cases, surrogate elements (lanthanides) were used in place of radioactive ones. The experiments were conducted utilizing a small DC arc melter developed at the Idaho National Engineering Laboratory (INEL) Research Center (IRC). The small arc melter was originally developed in 1992 and has been used previously for waste form studies of iron enriched basalt (IEB) and IEB with zirconium and titanium additions (IEB4). Section 3 contains a description of the small arc melter and its operational capabilities are discussed in Chapter 4. The remainder of the document describes each testing program and then discusses results and findings.

  16. GMO Guide: How do I manage my ARC grant? Part 1: What are my ongoing responsibilities?

    E-Print Network [OSTI]

    New South Wales, University of

    1 GMO Guide: How do I manage my ARC grant? Part 1: What are my ongoing responsibilities? This GMO a completed Acceptance Form has been received by the Grants Management Office (GMO), the Funding Agreement

  17. Low pressure arc discharge lamp apparatus with magnetic field generating means

    DOE Patents [OSTI]

    Grossman, M.W.; George, W.A.; Maya, J.

    1987-10-06

    A low-pressure arc discharge apparatus having a magnetic field generating means for increasing the output of a discharge lamp is disclosed. The magnetic field generating means, which in one embodiment includes a plurality of permanent magnets, is disposed along the lamp for applying a constant transverse magnetic field over at least a portion of the positive discharge column produced in the arc discharge lamp operating at an ambient temperature greater than about 25 C. 3 figs.

  18. Asymmetric injection of cathodic arc plasma into a macroparticlefilter

    SciTech Connect (OSTI)

    Anders, Andre; MacGill, Robert A.

    2004-02-11

    The cathodic arc plasmas produced by cathode spots usuallyinclude macroparticles, which is undesirable for many applications. Acommon way of removing macroparticles is to use curved solenoid filterswhich guide the plasma from the source to the substrate. In this work, anarc source with relatively small cathode is used, limiting the possiblelocations of plasma production. The relative position of cathodic arcsource and macroparticle filtered was systematically varied and thefiltered plasma current was recorded. It was found that axis-symmetricplasma injection leads to maximum throughput only if an anode aperturewas used, which limited the plasma to near-axis flow by scraping offplasma at larger angles to the axis. When the anode aperture was removed,more plasma could enter the filter. In this case, maximum filtered ioncurrent was achieved when the plasma was injected off-axis, namely offsetin the direction where the filter is curved. Such behavior wasanticipated because the plasma column in the filter is known to beshifted by ExB and centrifugal drift as well as by non-axis-symmetriccomponents of the magnetic field in the filter entrance and exit plane.The data have implications for plasma transport variations caused bydifferent spot locations on cathodes that are not small compared to thefilter cross section.

  19. Stainless steel submerged arc weld fusion line toughness

    SciTech Connect (OSTI)

    Rosenfield, A.R.; Held, P.R.; Wilkowski, G.M. [Battelle, Columbus, OH (United States)

    1995-04-01

    This effort evaluated the fracture toughness of austenitic steel submerged-arc weld (SAW) fusion lines. The incentive was to explain why cracks grow into the fusion line in many pipe tests conducted with cracks initially centered in SAWS. The concern was that the fusion line may have a lower toughness than the SAW. It was found that the fusion line, Ji. was greater than the SAW toughness but much less than the base metal. Of greater importance may be that the crack growth resistance (JD-R) of the fusion line appeared to reach a steady-state value, while the SAW had a continually increasing JD-R curve. This explains why the cracks eventually turn to the fusion line in the pipe experiments. A method of incorporating these results would be to use the weld metal J-R curve up to the fusion-line steady-state J value. These results may be more important to LBB analyses than the ASME flaw evaluation procedures, since there is more crack growth with through-wall cracks in LBB analyses than for surface cracks in pipe flaw evaluations.

  20. Modelling on dynamics properties of a stationary argon cascaded arc plasma flows

    SciTech Connect (OSTI)

    Wei, G. D.; Qi, X.; Yang, L.

    2014-03-15

    The gas dynamics properties of a stationary arc plasma flows are studied through the numerical simulations. A two dimensional axis-symmetric turbulent magneto-hydrodynamic plasma model is developed with the commercial code ANSYS FLUENT. The reliable ?-? model is used to account for turbulence. In this paper, the plasma is assumed to be a fluid following NavierStokes equations, respecting local thermodynamic equilibrium, and described by only one temperature. Distributions of the pressure, velocity, temperature, density, and electric potential inside of thus cascaded arc are obtained for an arc current density of 10{sup 6}?A/m{sup 2}. The pressure inside the arc varies from 10{sup 5}?Pa to 100?Pa. The temperature at the arc axis can reach as high as 13?600?K. The electric potential drops uniformly along the axis with a magnitude of 160?V. In addition, distributions of the sonic velocity and Mach number are shown to describe supersonic behavior of thus cascaded arc, which have a good agreement with the analytical formula.

  1. Electrical and thermal finite element modeling of arc faults in photovoltaic bypass diodes.

    SciTech Connect (OSTI)

    Bower, Ward Isaac; Quintana, Michael A.; Johnson, Jay

    2012-01-01

    Arc faults in photovoltaic (PV) modules have caused multiple rooftop fires. The arc generates a high-temperature plasma that ignites surrounding materials and subsequently spreads the fire to the building structure. While there are many possible locations in PV systems and PV modules where arcs could initiate, bypass diodes have been suspected of triggering arc faults in some modules. In order to understand the electrical and thermal phenomena associated with these events, a finite element model of a busbar and diode was created. Thermoelectrical simulations found Joule and internal diode heating from normal operation would not normally cause bypass diode or solder failures. However, if corrosion increased the contact resistance in the solder connection between the busbar and the diode leads, enough voltage potentially would be established to arc across micron-scale electrode gaps. Lastly, an analytical arc radiation model based on observed data was employed to predicted polymer ignition times. The model predicted polymer materials in the adjacent area of the diode and junction box ignite in less than 0.1 seconds.

  2. Temporal Development of Ion Beam Mean Charge State in PulsedVacuum Arc Ion Sources

    SciTech Connect (OSTI)

    Oks, Efim M.; Yushkov, Georgy Yu.; Anders, Andre

    2007-06-21

    Vacuum arc ion sources, commonly also known as "Mevva" ionsources, are used to generate intense pulsed metal ion beams. It is knownthat the mean charge state of the ion beam lies between 1 and 4,depending on cathode material, arc current, arc pulse duration, presenceor absence of magnetic field at the cathode, as well background gaspressure. A characteristic of the vacuum arc ion beam is a significantdecrease in ion charge state throughout the pulse. This decrease can beobserved up to a few milliseconds, until a "noisy" steady-state value isestablished. Since the extraction voltage is constant, a decrease in theion charge state has a proportional impact on the average ion beamenergy. This paper presents results of detailed investigations of theinfluence of arc parameters on the temporal development of the ion beammean charge state for a wide range of cathode materials. It is shown thatfor fixed pulse duration, the charge state decrease can be reduced bylower arc current, higher pulse repetition rate, and reduction of thedistance between cathode and extraction region. The latter effect may beassociated with charge exchange processes in the dischargeplasma.

  3. Formation of Self-Organized Anode Patterns in Arc Discharge Simulations

    E-Print Network [OSTI]

    Juan Pablo Trelles

    2012-12-31

    Pattern formation and self-organization are phenomena commonly observed experimentally in diverse types of plasma systems, including atmospheric-pressure electric arc discharges. However, numerical simulations reproducing anode pattern formation in arc discharges have proven exceedingly elusive. Time-dependent three-dimensional thermodynamic nonequilibrium simulations reveal the spontaneous formation of self-organized patterns of anode attachment spots in the free-burning arc, a canonical thermal plasma flow established by a constant DC current between an axi-symmetric electrodes configuration in the absence of external forcing. The number of spots, their size, and distribution within the pattern depend on the applied total current and on the resolution of the spatial discretization, whereas the main properties of the plasma flow, such as maximum temperatures, velocity, and voltage drop, depend only on the former. The sensibility of the solution to the spatial discretization stresses the computational requirements for comprehensive arc discharge simulations. The obtained anode patterns qualitatively agree with experimental observations and confirm that the spots originate at the fringes of the arc - anode attachment. The results imply that heavy-species - electron energy equilibration, in addition to thermal instability, has a dominant role in the formation of anode spots in arc discharges.

  4. JEMMRLA - Electron Model of a Muon RLA with Multi-pass Arcs

    SciTech Connect (OSTI)

    Bogacz, Slawomir Alex; Krafft, Geoffrey A.; Morozov, Vasiliy S.; Roblin, Yves R.

    2013-06-01

    We propose a demonstration experiment for a new concept of a 'dogbone' RLA with multi-pass return arcs -- JEMMRLA (Jlab Electron Model of Muon RLA). Such an RLA with linear-field multi-pass arcs was introduced for rapid acceleration of muons for the next generation of Muon Facilities. It allows for efficient use of expensive RF while the multi-pass arc design based on linear combined-function magnets exhibits a number of advantages over separate-arc or pulsed-arc designs. Here we describe a test of this concept by scaling a GeV scale muon design for electrons. Scaling muon momenta by the muon-to-electron mass ratio leads to a scheme, in which a 4.5 MeV electron beam is injected in the middle of a 3 MeV/pass linac with two double-pass return arcs and is accelerated to 18 MeV in 4.5 passes. All spatial dimensions including the orbit distortion are scaled by a factor of 7.5, which arises from scaling the 200 MHz muon RF to a readily available 1.5 GHz. The hardware requirements are not very demanding making it straightforward to implement. Such an RLA may have applications going beyond muon acceleration: in medical isotope production, radiation cancer therapy and homeland security.

  5. An evaluation of the geothermal potential of the Tecuamburro Volcano area of Guatemala

    SciTech Connect (OSTI)

    Heiken, G.; Duffield, W. (eds.)

    1990-09-01

    Radiometric ages indicate that the Tecuamburro Volcano and three adjacent lava domes grew during the last 38,300 years, and that a 360-m-wide phreatic crater, Laguna Ixpaco, was formed near the base of these domes about 2900 years ago. Laguna Ixpaco is located within the Chupadero crater, from which pyroxene pumice deposits were erupted 38,300 years ago. Thus, the likelihood is great for a partly molten or solid-but-still-hot near-surface intrusion beneath the area. Fumaroles and hot springs issue locally from the Tecuamburro volcanic complex and near Laguna Ixpaco. Analyses of gas and fluid samples from these and other nearby thermal manifestations yield chemical-geothermometer temperatures of about 150{degree} to 300{degree}C, with the highest temperatures at Ixpaco. The existence of a commercial-grade geothermal reservoir beneath the Ixpaco area seems likely. 84 refs., 70 figs., 12 tabs.

  6. UNCOVERING BURIED VOLCANOES: NEW DATA FOR PROBABILISTIC VOLCANIC HAZARD ASSESSMENT AT YUCCA MOUNTAIN

    SciTech Connect (OSTI)

    F.V. Perry

    2005-10-13

    Basaltic volcanism poses a potential hazard to the proposed Yucca Mountain nuclear waste repository because multiple episodes of basaltic volcanism have occurred in the Yucca Mountain region (YMR) in the past 11 Ma. Intervals between eruptive episodes average about 1 Ma. Three episodes have occurred in the Quaternary at approximately 1.1 Ma (5 volcanoes), 350 ka (2 volcanoes), and 80 ka (1 volcano). Because Yucca Mountain lies within the Basin and Range Province, a significant portion of the pre-Quaternary volcanic history of the YMR may be buried in alluvial-filled basins. An exceptionally high-resolution aeromagnetic survey and subsequent drilling program sponsored by the U.S. Department of Energy (DOE) began in 2004 and is gathering data that will enhance understanding of the temporal and spatial patterns of Pliocene and Miocene volcanism in the region (Figure 1). DOE has convened a ten-member expert panel of earth scientists that will use the information gathered to update probabilistic volcanic hazard estimates originally obtained by expert elicitation in 1996. Yucca Mountain is a series of north-trending ridges of eastward-tilted fault blocks that are bounded by north to northeast-trending normal faults. Topographic basins filled with up to 500 m of alluvium surround it to the east, south and west. In the past several decades, nearly 50 holes have been drilled in these basins, mainly for Yucca Mountain Project Site Characterization and the Nye County Early Warning Drilling Program. Several of these drill holes have penetrated relatively deeply buried (300-400 m) Miocene basalt; a Pliocene basalt dated at 3.8 Ma was encountered at a relatively shallow depth (100 m) in the northern Amargosa Desert (Anomaly B in Figure 1). The current drilling program is the first to specifically target and characterize buried basalt. Based on the new aeromagnetic survey and previous air and ground magnetic surveys (Connor et al. 2000; O'Leary et al. 2002), at least eight drill holes are planned with the goal of sampling each geographic subpopulation of magnetic anomalies in the region (Figure 1). This will result in a more complete characterization of the location, age, volume and composition of buried basaltic features for the purpose of updating the volcanic hazard assessment. Smith and Keenan (2005) suggested that volcanic hazard estimates might be 1-2 orders of magnitude higher than estimated by the DOE expert elicitation in 1996, based on (1) a proposed relationship between recurrence rates in the YMR and the Reveille-Lunar Crater volcanic field to the north, and (2) the implication that a number of so-far-undiscovered buried volcanoes would have a significant impact on hazard estimates. This article presents the new aeromagnetic data and an interpretation of the data that suggests magnetic anomalies nearest the proposed repository site represent buried Miocene basalt that will likely have only a minor impact on the volcanic hazard.

  7. Some effects of the emissions of explosive volcanoes on the stratosphere

    SciTech Connect (OSTI)

    Cadle, R.D.

    1980-08-20

    A previously published 2-D numerical model of the global dispersion of an eruption cloud in the stratosphere as a function of time assumed an instantaneous injection of the eruption cloud (the source function). New calculations show that the dispersion rate is quite insensitive to the manner of introducing the source function into the model, including spreading the eruption time over 10 days. Results obtained by flying through the eruption clouds from explosive volcanoes in Guatemala indicated that most of the sulfur in such clouds is SO/sub 2/. If, as is generally believed, SO/sub 2/ reacts with OH in the stratosphere, leading to the production of H/sub 2/SO/sub 4/ droplets, high explosive eruptions can deplete the stratosphere of OH for long time periods. The OH is thus controlled by the rate of O(/sup 1/D) formation from ozone. By using the results from the 2-D dispersion model referred to above applied to the eruption cloud from the 1953 Agung eruption, and chemical kinetic rate constants, the 'e folding' residence time for sulfur dioxide conversion to sulfuric acid was estimated to be about 300 days. The Guatemala studies showed that the eruption clouds from explosive volcanoes contain large amounts of HCl. Unless much of this HCl is removed by rain accompanying the eruption, this HCl might be expected to have a marked influence on stratospheric chemistry as a result of the reaction OH+HCl..-->..H/sub 2/O+Cl. The volcanic HCl will probably remove OH much less rapidly than will SO/sub 2/, and if the OH concentration is greatly decreased by the SO/sub 2/, the above reaction may be too slow to be important.

  8. Two-dimensional simulations of explosive eruptions of Kick-em Jenny and other submarine volcanos

    SciTech Connect (OSTI)

    Gisler, Galen R.; Weaver, R. P. (Robert P.); Mader, Charles L.; Gittings, M. L. (Michael L.)

    2004-01-01

    Kick-em Jenny, in the Eastern Caribbean, is a submerged volcanic cone that has erupted a dozen or more times since its discovery in 1939. The most likely hazard posed by this volcano is to shipping in the immediate vicinity (through volcanic missiles or loss-of-buoyancy), but it is of interest to estimate upper limits on tsunamis that might be produced by a catastrophic explosive eruption. To this end, we have performed two-dimensional simulations of such an event in a geometry resembling that of Kick-em Jenny with our SAGE adaptive mesh Eulerian multifluid compressible hydrocode. We use realistic equations of state for air, water, and basalt, and follow the event from the initial explosive eruption, through the generation of a transient water cavity and the propagation of waves away from the site. We find that even for extremely catastrophic explosive eruptions, tsunamis from Kick-em Jenny are unlikely to pose significant danger to nearby islands. For comparison, we have also performed simulations of explosive eruptions at the much larger shield volcano Vailuluu in the Samoan chain, where the greater energy available can produce a more impressive wave. In general, however, we conclude that explosive eruptions do not couple well to water waves. The waves that are produced from such events are turbulent and highly dissipative, and don't propagate well. This is consistent with what we have found previously in simulations of asteroid-impact generated tsunamis. Non-explosive events, however, such as landslides or gas hydrate releases, do couple well to waves, and our simulations of tsunamis generated by subaerial and sub-aqueous landslides demonstrate this.

  9. Predicting and validating the tracking of a Volcanic Ash Cloud during the 2006 Eruption of Mt. Augustine Volcano

    SciTech Connect (OSTI)

    Webley, Peter W.; Atkinson, D.; Collins, Richard L.; Dean, K.; Fochesatto, J.; Sassen, Kenneth; Cahill, Catherine F.; Prata, A.; Flynn, Connor J.; Mizutani, K.

    2008-11-01

    On 11 January 2006, Mount Augustine volcano in southern Alaska began erupting after 20-year repose. The Anchorage Forecast Office of the National Weather Service (NWS) issued an advisory on 28 January for Kodiak City. On 31 January, Alaska Airlines cancelled all flights to and from Anchorage after multiple advisories from the NWS for Anchorage and the surrounding region. The Alaska Volcano Observatory (AVO) had reported the onset of the continuous eruption. AVO monitors the approximately 100 active volcanoes in the Northern Pacific. Ash clouds from these volcanoes can cause serious damage to an aircraft and pose a serious threat to the local communities, and to transcontinental air traffic throughout the Arctic and sub-Arctic region. Within AVO, a dispersion model has been developed to track the dispersion of volcanic ash clouds. The model, Puff, was used operational by AVO during the Augustine eruptive period. Here, we examine the dispersion of a volcanic ash cloud from Mount Augustine across Alaska from 29 January through the 2 February 2006. We present the synoptic meteorology, the Puff predictions, and measurements from aerosol samplers, laser radar (or lidar) systems, and satellites. UAF aerosol samplers revealed the presence of volcanic aerosols at the surface at sites where Puff predicted the ash clouds movement. Remote sensing satellite data showed the development of the ash cloud in close proximity to the volcano and a sulfur-dioxide cloud further from the volcano consistent with the Puff predictions. Lidars showed the presence of volcanic aerosol with consistent characteristics aloft over Alaska and were capable of detecting the aerosol, even in the presence of scattered clouds and where the cloud is too thin/disperse to be detected by remote sensing satellite data. The lidar measurements revealed the different trajectories of ash consistent with the Puff predictions. Dispersion models provide a forecast of volcanic ash cloud movement that might be undetectable by any other means but are still a significant hazard. Validation is the key to assessing the accuracy of any future predictions. The study highlights the use of multiple and complementary observations used in detecting the trajectory ash cloud, both at the surface and aloft within the atmosphere.

  10. Debris Flow Mapping Through TimeDebris Flow Mapping Through Time Data Management using ArcGIS andData Management using ArcGIS and

    E-Print Network [OSTI]

    Debris Flow Mapping Through TimeDebris Flow Mapping Through Time Data Management using ArcGIS and EventsChannel Reorganizing Events Debris FlowsDebris Flows HyperHyper--concentrated Flowsconcentrated Flows #12;1.The rapid, downward mass movement of particles coarser than sand, often including boulders

  11. Gaseous and particulate emissions from a DC arc melter

    SciTech Connect (OSTI)

    Overcamp, T.J.; Speer, M.P.; Griner, S.J.; Cash, D.M. [Clemson Univ., Anderson, SC (United States)

    1997-12-31

    This paper presents the results of the gaseous and particulate emissions from eight experimental tests of a DC arc melter to treat simulated Savannah River soils contaminated with metals, surrogates for radionuclides, and organic debris. The gaseous analyses reported on the concentrations of oxygen, hydrogen, carbon monoxide, carbon dioxide, hydrogen, methane, nitric oxide, and nitrogen dioxide. The carbon dioxide concentration was high for all runs. For the runs with an air purge, the carbon monoxide concentration ranged up to 10% in the runs with the debris and 2% in the runs without debris. Hydrogen ranged up to 5% by with debris and up to 1% without debris. The methane concentration ranged up to 7,000 ppm{sub v} for the runs with debris and 2,000 ppm for the runs without debris. With a nitrogen purge, oxygen concentrations were less than 1%. The carbon dioxide concentrations ranged from 3 to 15%. Much of this carbon dioxide was probably due the carbonates added to the feed material. The carbon monoxide concentration ranged up to 20% with the debris and 7% without debris. Hydrogen was above 6% in with debris and up to 6% without debris. The methane concentration ranged up to 10,000 ppm{sub v} with debris and 4,000 ppm{sub v} without debris. The particulate concentrations exiting ranged from 32 to 145 g/m{sup 3}. From the chemical analyses, the primary elements were silicon and calcium. The CHN analyses indicated that carbon, probably as carbonates, are an additional component in the particulate matter. The estimated emissions were at a level of 3% or less for cerium, up to 7% for nickel, and 11 to 30% for cesium.

  12. Glow-to-arc transition events in H{sub 2}-Ar direct current pulsed plasma: Automated measurement of current and voltage

    SciTech Connect (OSTI)

    Mendes, Luciano A.; Rodrigues, Jhonatam C.; Mafra, Marcio

    2012-01-15

    The glow-to-arc transition phenomena (arcing) observed in plasma reactors used in materials processing was studied through the arcs characteristic current and voltage waveforms. In order to capture these arcs signals, a LABVIEW based automated instrumentation system (ARCVIEW) was developed, including the integration of an oscilloscope equipped with proper current and voltage probes. The system also allows capturing the process parameters at the arc occurrence moments, which were used to map the arcs events conditions. Experiments in H{sub 2}-Ar DC pulsed plasma returned signals data from 215 arcs events, which were analyzed through software routines. According to the results, an anti-arcing system should react in the time order of few microseconds to prevent most of the damage caused by the undesired arcing phenomena.

  13. A beginner's guide to stereo-derived DEM production and analysis using ISIS, ASP, and ArcMap

    E-Print Network [OSTI]

    Rathbun, Julie A.

    A beginner's guide to stereo-derived DEM production and analysis using ISIS, ASP, and ArcMap v. 1 ............................................................................................................................5 2. Processing the images with ISIS

  14. Jurassic arc volcanism on Crimea (Ukraine): Implications for the paleo-subduction zone configuration of the Black Sea region

    E-Print Network [OSTI]

    Utrecht, Universiteit

    Jurassic arc volcanism on Crimea (Ukraine): Implications for the paleo-subduction zone margin. Crimea (Ukraine), a peninsula in the northern Black Sea, represents the northernmost region

  15. Composition of modern sand from the Sierra Nevada, California, USA: Implications for actualistic petrofacies of continental-margin magmatic arcs

    E-Print Network [OSTI]

    Ingersoll, Raymond V.; Eastmond, Daniel J.

    2007-01-01

    variability of modern sands: Sedimentary Geology, v. 171, p.nonquartzose) lithic (L) sand(stone) composition. Designatedpredicted trend for sand(stone) composition during arc

  16. Cosmology through arc statistics I: sensitivity to $\\Omega_m$ and $\\sigma_8$

    E-Print Network [OSTI]

    Boldrin, Michele; Meneghetti, Massimo; Moscardini, Lauro; Tormen, Giuseppe; Biviano, Andrea

    2015-01-01

    The next generation of large sky photometric surveys will finally be able to use arc statistics as a cosmological probe. Here we present the first of a series of papers on this topic. In particular, we study how arc counts are sensitive to the variation of two cosmological parameters: the (total) matter density parameter, $\\Omega_m$, and the normalisation of the primordial power spectrum, expressed in terms of $\\sigma_8$. Both these parameters influence the abundances of collapsed structures and their internal structure. We compute the expected number of gravitational arcs with various length-to-width ratios in mock light cones, by varying these cosmological parameters in the ranges $0.1\\leq\\Omega_m\\leq0.5$ and $0.6\\leq\\sigma_8\\leq 1$. We find that the arc counts dependence on $\\Omega_m$ and $\\sigma_8$ is similar, but not identical, to that of the halo counts. We investigate how the precision of the constraints on the cosmological parameters based on arc counts depends on the survey area. We find that the con...

  17. Characterization of a Filtered High Current Pulsed Cathodic Vacuum Arc Plasma Source: Plasma Transport Analysis

    SciTech Connect (OSTI)

    Sangines, R.; Tarrant, R. N.; Bilek, M. M. M.; McKenzie, D. R.; Andruczyk, D.

    2008-03-19

    Studies of plasma behavior produced by a filtered high current pulsed cathodic vacuum arc system are reported. Titanium plasma is initiated from the cathode by surface flash over triggering at the centre of the cathode disk. The multiple arc spots move outwards due to their mutual repulsion and the arc current pulse is terminated as the arc spots reach the edge of the cathode disk. The plasma moves into a positively biased quarter-torus magnetic filter and is guided towards the substrate position located 150 mm beyond the filter exit. Electron density and plasma current measurements have been employed to analyze the transport of the plasma associated with different cathode currents, and its dependence on confining magnetic field and bias conditions. For a given cathode current, the optimum plasma transport to the substrate requires the right combination of the strength of the confining magnetic field and the magnetic filter positive bias. The optimum values of these two parameters were found to increase with increasing cathode current. Initially the optimum throughput of plasma increases more strongly than the arc current (roughly 1.5 times the increase in the current); however, at high cathode current regimes (2.4 kA) a significant change of the plasma behavior is seen and transport efficiency is reduced.

  18. Investigation on oblique shock wave control by arc discharge plasma in supersonic airflow

    SciTech Connect (OSTI)

    Wang Jian; Li Yinghong; Xing Fei

    2009-10-01

    Wedge oblique shock wave control by arc discharge plasma in supersonic airflow was investigated theoretically, experimentally, and numerically in this paper. Using thermal choking model, the change in oblique shock wave was deduced, which refer that the start point of shock wave shifts upstream, the shock wave angle decreases, and its intensity weakens. Then the theoretical results were validated experimentally in a Mach 2.2 wind tunnel. On the test conditions of arc discharge power of approx1 kW and arc plasma temperature of approx3000 K, schlieren photography and gas pressure measurements indicated that the start point of shock wave shifted upstream of approx4 mm, the shock wave angle decreased 8.6%, and its intensity weakened 8.8%. The deduced theoretical results match the test results qualitatively, so thermal mechanism and thermal choking model are rational to explain the problem of oblique shock wave control by arc discharge plasma. Finally, numerical simulation was developed. Based on thermal mechanism, the arc discharge plasma was simplified as a thermal source term that added to the Navier-Stokes equations. The simulation results of the change in oblique shock wave were consistent with the test results, so the thermal mechanism indeed dominates the oblique shock wave control process.

  19. Three-dimensional model and simulation of vacuum arcs under axial magnetic fields

    SciTech Connect (OSTI)

    Wang Lijun; Jia Shenli; Zhou Xin; Wang Haijing; Shi Zongqian

    2012-01-15

    In this paper, a three-dimensional (3d) magneto-hydro-dynamic (MHD) model of axial magnetic field vacuum arcs (AMFVAs) is established. Based on this model, AMFVAs are simulated and analyzed. Three-dimensional spatial distributions of many important plasma parameters and electric characteristics in AMFVAs can be obtained, such as ion number density, ion temperature, electron temperature, plasma pressure, current densities along different directions (x, y, and z), ion velocities along different directions, electric fields strength along different directions, and so on. Simulation results show that there exist significant spiral-shaped rotational phenomena in the AMFVAs, this kind of rotational phenomenon also can be verified by the many related experiments (AMFVAs photographs, especially for stronger AMF strength). For current simulation results of AMFVAs, the maximal rotational velocity at anode side is about 1100 m/s. Radial electric field is increased from arc center to arc edge; axial electric field is decreased from cathode side to anode side. Radial electric field at arc edge can be larger than axial electric field. Azimuthal electric field in most regions is much smaller than radial and axial electric field, but it can reach about 1.19 kV/m. Radial magnetic field is the smallest one compared with other components, it reaches to maximum value at the position near to anode, it can influence arc characteristics.

  20. The electron cyclotron resonance ion source with arc-shaped coils concept (invited)

    SciTech Connect (OSTI)

    Koivisto, H.; Tarvainen, O.; Suominen, P.; Spaedtke, P.

    2012-02-15

    The main limitation to further improve the performance of ECR ion sources is set by the magnet technology related to the multipole magnet field used for the closed minimum-B structure. The JYFL ion source group has sought different approaches to improve the strength of the minimum-B structure required for the production of highly charged ion beams. It was found out that such a configuration can be realized with arc shaped coils. The first prototype, electron cyclotron resonance ion source with arc-shaped coils (ARC-ECRIS), was constructed and tested at JYFL in 2006. It was confirmed that such an ion source can be used for the production of highly charged ion beams. Regardless of several cost-driven compromises such as extraction mirror ratio of 1.05-1.2, microwave frequency of 6.4 GHz, and beam line with limited capacity, Ar{sup 4+} beam intensity of up to 2 {mu}A was measured. Subsequent design study has shown that the ARC-ECRIS operating at the microwave frequency above 40 GHz could be constructed. This specific design would be based on NbTi-wires and it fulfills the experimental magnetic field scaling laws. In this article, the ARC-ECRIS concept and its potential applications will be described.

  1. A study of vacuum arc ion velocities using a linear set of probes

    SciTech Connect (OSTI)

    Hohenbild, Stefan; Grubel, Christoph; Yushkov, Georgy Yu.; Oks, Efim M.; Anders, Andre

    2008-07-15

    The most likely velocity of ions moving away from vacuum arc cathode spots was measured using a set of probes along the path of plasma expansion. The goal was to determine how much, if any, change of the ion drift velocity occurs in the expanded plasma. The arc discharge current was perturbed to create plasma density markers whose travel is picked up by the set of probes. It was found that the perturbation with current oscillations did not result in consistent data because ion current maxima and minima are not only determined by the plasma production but by the transients of the arc pulse and by the asymmetry of the ion velocity distribution function. Perturbation with a short current spike was more conclusive. The ion velocity was measured to be slightly reduced with increasing distance from the cathode, which can be explained by collisions of ions with the background of neutrals. The ion velocity was increased when the arc current was increased, which correlated with enhanced arc voltage and power dissipation. The ion velocity could be enhanced when the plasma was produced in a non-uniform magnetic field.

  2. Computational study of flow dynamics from a dc arc plasma jet

    E-Print Network [OSTI]

    Juan Pablo Trelles

    2013-03-15

    Plasma jets produced by direct-current (DC) non-transferred arc plasma torches, at the core of technologies ranging from spray coating to pyrolysis, present intricate dynamics due to the coupled interaction of fluid flow, thermal, and electromagnetic phenomena. The flow dynamics from an arc discharge plasma jet are investigated using time-dependent three-dimensional simulations encompassing the dynamics of the arc inside the torch, the evolution of the jet through the discharge environment, and the subsequent impingement of the jet over a flat substrate. The plasma is described by a chemical equilibrium and thermodynamic nonequilibrium (two-temperature) model. The numerical formulation of the physical model is based on a monolithic and fully-coupled treatment of the fluid and electromagnetic equations using a Variational Multiscale Finite Element Method. Simulation results uncover distinct aspects of the flow dynamics, including the jet forcing due to the movement of the electric arc, the prevalence of deviations between heavy-species and electron temperatures in the plasma fringes, the development of shear flow instabilities around the jet, the occurrence of localized regions with high electric fields far from the arc, and the formation and evolution of coherent flow structures.

  3. Optical emission from a small scale model electric arc furnace in 250-600 nm region

    SciTech Connect (OSTI)

    Maekinen, A.; Tikkala, H.; Aksela, H.; Niskanen, J.

    2013-04-15

    Optical emission spectroscopy has been for long proposed for monitoring and studying industrial steel making processes. Whereas the radiative decay of thermal excitations is always taking place in high temperatures needed in steel production, one of the most promising environment for such studies are electric arc furnaces, creating plasma in excited electronic states that relax with intense characteristic emission in the optical regime. Unfortunately, large industrial scale electric arc furnaces also present a challenging environment for optical emission studies and application of the method is not straightforward. To study the usability of optical emission spectroscopy in real electric arc furnaces, we have developed a laboratory scale DC electric arc furnace presented in this paper. With the setup, optical emission spectra of Fe, Cr, Cr{sub 2}O{sub 3}, Ni, SiO{sub 2}, Al{sub 2}O{sub 3}, CaO, and MgO were recorded in the wavelength range 250-600 nm and the results were analyzed with the help of reference data. The work demonstrates that using characteristic optical emission, obtaining in situ chemical information from oscillating plasma of electric arc furnaces is indeed possible. In spite of complications, the method could possibly be applied to industrial scale steel making process in order to improve its efficiency.

  4. Direct-current cathodic vacuum arc system with magnetic-field mechanism for plasma stabilization

    SciTech Connect (OSTI)

    Zhang, H.-S.; Komvopoulos, K.

    2008-07-15

    Filtered cathodic vacuum arc (FCVA) deposition is characterized by plasma beam directionality, plasma energy adjustment via substrate biasing, macroparticle filtering, and independent substrate temperature control. Between the two modes of FCVA deposition, namely, direct current (dc) and pulsed arc, the dc mode yields higher deposition rates than the pulsed mode. However, maintaining the dc arc discharge is challenging because of its inherent plasma instabilities. A system generating a special configuration of magnetic field that stabilizes the dc arc discharge during film deposition is presented. This magnetic field is also part of the out-of-plane magnetic filter used to focus the plasma beam and prevent macroparticle film contamination. The efficiency of the plasma-stabilizing magnetic-field mechanism is demonstrated by the deposition of amorphous carbon (a-C) films exhibiting significantly high hardness and tetrahedral carbon hybridization (sp{sup 3}) contents higher than 70%. Such high-quality films cannot be produced by dc arc deposition without the plasma-stabilizing mechanism presented in this study.

  5. ZrN coatings deposited by high power impulse magnetron sputtering and cathodic arc techniques

    SciTech Connect (OSTI)

    Purandare, Yashodhan Ehiasarian, Arutiun; Hovsepian, Papken; Santana, Antonio

    2014-05-15

    Zirconium nitride (ZrN) coatings were deposited on 1??m finish high speed steel and 316L stainless steel test coupons. Cathodic Arc (CA) and High Power Impulse Magnetron Sputtering (HIPIMS) + Unbalanced Magnetron Sputtering (UBM) techniques were utilized to deposit coatings. CA plasmas are known to be rich in metal and gas ions of the depositing species as well as macroparticles (droplets) emitted from the arc sports. Combining HIPIMS technique with UBM in the same deposition process facilitated increased ion bombardment on the depositing species during coating growth maintaining high deposition rate. Prior to coating deposition, substrates were pretreated with Zr{sup +} rich plasma, for both arc deposited and HIPIMS deposited coatings, which led to a very high scratch adhesion value (L{sub C2}) of 100 N. Characterization results revealed the overall thickness of the coatings in the range of 2.5??m with hardness in the range of 3040?GPa depending on the deposition technique. Cross-sectional transmission electron microscopy and tribological experiments such as dry sliding wear tests and corrosion studies have been utilized to study the effects of ion bombardment on the structure and properties of these coatings. In all the cases, HIPIMS assisted UBM deposited coating fared equal or better than the arc deposited coatings, the reasons being discussed in this paper. Thus H+U coatings provide a good alternative to arc deposited where smooth, dense coatings are required and macrodroplets cannot be tolerated.

  6. Free fall plasma-arc reactor for synthesis of carbon nanotubes in microgravity

    SciTech Connect (OSTI)

    Alford, J. M.; Mason, G. R.; Feikema, D. A.

    2006-07-15

    High temperatures inside the plasma of a carbon arc generate strong buoyancy driven convection which has an effect on the growth and morphology of the single-walled carbon nanotubes (SWNTs). To study the effect of buoyancy on the arc process, a miniature carbon arc apparatus was designed and developed to synthesize SWNTs in a microgravity environment substantially free from buoyant convective flows. An arc reactor was operated in the 2.2 and 5.18 s drop towers at the NASA Glenn Research Center. The apparatus employed a 4 mm diameter anode and was powered by a portable battery pack capable of providing in excess of 300 A at 30 V to the arc for the duration of a 5 s drop. However, the principal result is that no dramatic difference in sample yield or composition was noted between normal gravity and 2.2 and 5 s long microgravity runs. Much longer duration microgravity time is required for SWNT's growth such as the zero-G aircraft, but more likely will need to be performed on the international space station or an orbiting spacecraft.

  7. Electron Model Of A Dogbone RLA With Multi-Pass Arcs

    SciTech Connect (OSTI)

    Beard, Kevin B.; Roblin, Yves R.; Morozov, Vasiliy; Bogacz, Slawomir Alex; Krafft, Geoffrey A.

    2012-09-01

    The design of a dogbone Recirculated Linear Accelerator, RLA, with linear-field multi-pass arcs was earlier developed [1] for accelerating muons in a Neutrino Factory and a Muon Collider. It allows for efficient use of expensive RF while the multi-pass arc design based on linear combined-function magnets exhibits a number of advantages over separate-arc or pulsed-arc designs. Such an RLA may have applications going beyond muon acceleration. This paper describes a possible straightforward test of this concept by scaling a GeV scale muon design for electrons. Scaling muon momenta by the muon-to-electron mass ratio leads to a scheme, in which a 4.5 MeV electron beam is injected at the middle of a 3 MeV/pass linac with two double-pass return arcs and is accelerated to 18 MeV in 4.5 passes. All spatial dimensions including the orbit distortion are scaled by a factor of 7.5, which arises from scaling the 200 MHz muon RF to the frequency readily available at CEBAF: 1.5 GHz. The footprint of a complete RLA fits in an area of 25 by 7 m. The scheme utilizes only fixed magnetic fields including injection and extraction. The hardware requirements are not very demanding, making it straightforward to implement

  8. Linear Fixed-Field Multi-Pass Arcs for Recirculating Linear Accelerators

    SciTech Connect (OSTI)

    V.S. Morozov, S.A. Bogacz, Y.R. Roblin, K.B. Beard

    2012-06-01

    Recirculating Linear Accelerators (RLA's) provide a compact and efficient way of accelerating particle beams to medium and high energies by reusing the same linac for multiple passes. In the conventional scheme, after each pass, the different energy beams coming out of the linac are separated and directed into appropriate arcs for recirculation, with each pass requiring a separate fixed-energy arc. In this paper we present a concept of an RLA return arc based on linear combined-function magnets, in which two and potentially more consecutive passes with very different energies are transported through the same string of magnets. By adjusting the dipole and quadrupole components of the constituting linear combined-function magnets, the arc is designed to be achromatic and to have zero initial and final reference orbit offsets for all transported beam energies. We demonstrate the concept by developing a design for a droplet-shaped return arc for a dog-bone RLA capable of transporting two beam passes with momenta different by a factor of two. We present the results of tracking simulations of the two passes and lay out the path to end-to-end design and simulation of a complete dog-bone RLA.

  9. Study on a negative hydrogen ion source with hot cathode arc discharge

    SciTech Connect (OSTI)

    Lin, S. H. Fang, X.; University of Chinese Academy of Sciences, Beijing 100039 ; Zhang, H. J.; Qian, C.; Ma, B. H.; Wang, H.; Li, X. X.; Zhang, X. Z.; Sun, L. T.; Zhang, Z. M.; Yuan, P.; Zhao, H. W.

    2014-02-15

    A negative hydrogen (H{sup ?}) ion source with hot cathode arc discharge was designed and fabricated as a primary injector for a 10 MeV PET cyclotron at IMP. 1 mA dc H{sup ?} beam with ? {sub N,} {sub RMS} = 0.08 ??mm?mrad was extracted at 25 kV. Halbach hexapole was adopted to confine the plasma. The state of arc discharge, the parameters including filament current, arc current, gas pressure, plasma electrode bias, and the ratio of I{sub e{sup ?}}/I{sub H{sup ?}} were experimentally studied. The discussion on the result, and opinions to improve the source were given.

  10. Spectroscopic characterization and imaging of laser- and unipolar arc-induced plasmas

    SciTech Connect (OSTI)

    Aussems, Damien U. B.; Nishijima, Daisuke; Brandt, Christian; Doerner, Russell P.; Cardozo, Niek J. Lopes

    2014-08-14

    Tungsten plasmas induced by unipolar arcs were investigated using optical emission spectroscopy and imaging, and compared with laser-induced tungsten plasmas. The unipolar arcs were initiated in the linear-plasma simulator PISCES-A at UCSD under fusion relevant conditions. The electron temperature and density of the unipolar arc plasmas were in the range 0.50.7?eV and 0.72.0??10{sup 20?}m{sup ?3}, respectively, and increased with increasing negative bias voltage, but did not correlate with the surface temperature. In comparison, the electron temperature and density of the laser-induced plasmas were in the range 0.61.4?eV and 7??10{sup 19}1??10{sup 22?}m{sup ?3}, respectively.

  11. Volumetric-modulated arc therapy (RapidArc) vs. conventional fixed-field intensity-modulated radiotherapy for {sup 18}F-FDG-PET-guided dose escalation in oropharyngeal cancer: A planning study

    SciTech Connect (OSTI)

    Teoh, May, E-mail: m.teoh@nhs.net [Department of Oncology, St. Luke's Cancer Centre, Royal Surrey County Hospital, Guildford, Surrey (United Kingdom); Beveridge, Sabeena [Department of Medical Physics, St. Luke's Cancer Centre, Royal Surrey County Hospital, Guildford, Surrey (United Kingdom); Wood, Katie; Whitaker, Stephen [Department of Oncology, St. Luke's Cancer Centre, Royal Surrey County Hospital, Guildford, Surrey (United Kingdom); Adams, Elizabeth; Rickard, Donna; Jordan, Tom; Nisbet, Andrew [Department of Medical Physics, St. Luke's Cancer Centre, Royal Surrey County Hospital, Guildford, Surrey (United Kingdom); Clark, Catharine H. [Department of Medical Physics, St. Luke's Cancer Centre, Royal Surrey County Hospital, Guildford, Surrey (United Kingdom); National Physical Laboratory, Hampton Road, Teddington, Middlesex (United Kingdom)

    2013-04-01

    Fluorine-18-fluorodeoxyglucose-positron emission tomography ({sup 18}F-FDG-PET)guided focal dose escalation in oropharyngeal cancer may potentially improve local control. We evaluated the feasibility of this approach using volumetric-modulated arc therapy (RapidArc) and compared these plans with fixed-field intensity-modulated radiotherapy (IMRT) focal dose escalation plans. Materials and methods: An initial study of 20 patients compared RapidArc with fixed-field IMRT using standard dose prescriptions. From this cohort, 10 were included in a dose escalation planning study. Dose escalation was applied to {sup 18}F-FDG-PETpositive regions in the primary tumor at dose levels of 5% (DL1), 10% (DL2), and 15% (DL3) above standard radical dose (65 Gy in 30 fractions). Fixed-field IMRT and double-arc RapidArc plans were generated for each dataset. Dose-volume histograms were used for plan evaluation and comparison. The Paddick conformity index (CI{sub Paddick}) and monitor units (MU) for each plan were recorded and compared. Both IMRT and RapidArc produced clinically acceptable plans and achieved planning objectives for target volumes. Dose conformity was significantly better in the RapidArc plans, with lower CI{sub Paddick} scores in both primary (PTV1) and elective (PTV2) planning target volumes (largest difference in PTV1 at DL3; 0.81 0.03 [RapidArc] vs. 0.77 0.07 [IMRT], p = 0.04). Maximum dose constraints for spinal cord and brainstem were not exceeded in both RapidArc and IMRT plans, but mean doses were higher with RapidArc (by 2.7 1 Gy for spinal cord and 1.9 1 Gy for brainstem). Contralateral parotid mean dose was lower with RapidArc, which was statistically significant at DL1 (29.0 vs. 29.9 Gy, p = 0.01) and DL2 (29.3 vs. 30.3 Gy, p = 0.03). MU were reduced by 39.849.2% with RapidArc (largest difference at DL3, 641 94 vs. 1261 118, p < 0.01). {sup 18}F-FDG-PETguided focal dose escalation in oropharyngeal cancer is feasible with RapidArc. Compared with conventional fixed-field IMRT, RapidArc can achieve better dose conformity, improve contralateral parotid sparing, and uses fewer MU.

  12. Emission and Absorption Spectroscopy of Carbon Arc Plasma during Formation of Carbon Magnetic Encapsulates

    SciTech Connect (OSTI)

    Lange, H.; Labedz, O.; Huczko, A.; Bystrzejewski, M.

    2011-11-29

    Plasma diagnostics of carbon arc discharge under conditions of carbon magnetic encapsulates formation was performed by emission and absorption spectroscopy. Content of C{sub 2} and Fe species, rotational temperatures of excited (d {sup 3} product {sub g}) and non-excited (a {sup 3} product {sub u}) states, and excitation temperatures of a {sup 5}F and a {sup 3}F levels relatively to the a {sup 5}D level of Fe atoms were determined. The results pointed to a non-equilibrium state of carbon arc plasma under prevailing discharge conditions.

  13. Super-radiance in the sodium resonance lines from sodium iodide arc lamps

    SciTech Connect (OSTI)

    Karabourniotis, D.; Drakakis, E.

    2010-08-09

    Super-radiance observed within the centers of the sodium resonance D lines emitted by arc lamps containing sodium iodide as additive in a high-pressure mercury plasma environment was studied by high-resolution emission spectroscopy. The spectral radiance of these self-reversed lines including super-radiance was simulated by considering a local enhancement of the source function due to the presence of an additional source of radiation near the arc wall. Causes of this hitherto unrecognized source of radiation are given.

  14. Heat flux characteristics in an atmospheric double arc argon plasma jet

    SciTech Connect (OSTI)

    Tu Xin; Yu Liang; Yan Jianhua; Cen Kefa; Cheron, Bruno

    2008-10-13

    In this study, the axial evolution of heat flux excited by a double arc argon plasma jet impinging on a flat plate is determined, while the nonstationary behavior of the heat flux is investigated by combined means of the fast Fourier transform, Wigner distribution, and short-time Fourier transform. Two frequency groups (<1 and 2-10 kHz) are identified in both the Fourier spectrum and the time-frequency distributions, which suggest that the nature of fluctuations in the heat flux is strongly associated with the dynamic behavior of the plasma arc and the engulfment of ambient air into different plasma jet regions.

  15. Optical Analysis Of The Vacuum Arc Plasma Generated In Cup-Shape Contacts

    SciTech Connect (OSTI)

    Pavelescu, G.; Gherendi, F.; Pavelescu, D.; Dumitrescu, G.; Anghelita, P.

    2007-04-23

    In this paper are presented the results of the optical analysis on the rotating arc plasma, generated in the vacuum low voltage circuit breaker with cup-shaped contacts. An adequate experimental setup was used for single shot time and spatial resolved spectroscopy in order to analyze the evolution of the vacuum arc plasma. Different current interruption situations are correlated with plasma spectral diagnosis. The study is aimed to contribute to a better understanding of the complex phenomena that take place in the interruption process of high currents that appears in the short-circuit regime of electrical networks.

  16. Chemistry of spring and well waters on Kilauea Volcano, Hawaii, and vicinity

    SciTech Connect (OSTI)

    Janik, C.J.; Nathenson, M.; Scholl, M.A.

    1994-12-31

    Published and new data for chemical and isotopic samples from wells and springs on Kilauea Volcano and vicinity are presented. These data are used to understand processes that determine the chemistry of dilute meteoric water, mixtures with sea water, and thermal water. Data for well and spring samples of non-thermal water indicate that mixing with sea water and dissolution of rock from weathering are the major processes that determine the composition of dissolved constituents in water. Data from coastal springs demonstrate that there is a large thermal system south of the lower east rift of Kilauea. Samples of thermal water from shallow wells in the lower east rift and vicinity have rather variable chemistry indicating that a number of processes operate in the near surface. Water sampled from the available deep wells is different in composition from the shallow thermal water, indicating that generally there is not a significant component of deep water in the shallow wells. Data for samples from available deep wells show significant gradients in chemistry and steam content of the reservoir fluid. These gradients are interpreted to indicate that the reservoir tapped by the existing wells is an evolving vapor-dominated system.

  17. Self-potential, soil co2 flux, and temperature on masaya volcano, nicaragua

    SciTech Connect (OSTI)

    Lewicki, J.L.; Connor, C.; St-Amand, K.; Stix, J.; Spinner, W.

    2003-07-01

    We investigate the spatial relationship between self-potential (SP), soil CO{sub 2} flux, and temperature and the mechanisms that produce SP anomalies on the flanks of Masaya volcano, Nicaragua. We measured SP, soil CO{sub 2} fluxes (<1 to 5.0 x 10{sup 4} g m{sup -2} d{sup -1}), and temperatures (26 to 80 C) within an area surrounding a normal fault, adjacent to Comalito cinder cone (2002-2003). These variables are well spatially correlated. Wavelengths of SP anomalies are {le}100 m, and high horizontal SP gradients flank the region of elevated flux and temperature. Carbon isotopic compositions of soil CO{sub 2} ({delta}{sup 13}C = -3.3 to -1.1{per_thousand}) indicate a deep gas origin. Given the presence of a deep water table (100 to 150 m), high gas flow rates, and subsurface temperatures above liquid boiling points, we suggest that rapid fluid disruption is primarily responsible for positive SP anomalies here. Concurrent measurement of SP, soil CO{sub 2} flux, and temperature may be a useful tool to monitor intrusive activity.

  18. Tecuamburro Volcano, Guatemala geothermal gradient core hole drilling, operations, and preliminary results

    SciTech Connect (OSTI)

    Goff, S.; Heiken, G.; Goff, F.; Gardner, J. (Los Alamos National Lab., NM (USA)); Duffield, W. (Geological Survey, Flagstaff, AZ (USA)); Martinelli, L.; Aycinena, S. (Swissboring Overseas Corp. Ltd., Guatemala City (Guatemala)); Castaneda, O. (Unidad de Desarrollo Geotermico, Guatemala City (Guatemala). Inst. Nacional de Electrificacion)

    1990-01-01

    A geothermal gradient core hole (TCB-1) was drilled to a depth of 700+ m at the Tecuamburro geothermal site, Guatemala during February and March, 1990. The core hole is located low on the northern flank of the Tecuamburro Volcano complex. Preliminary analysis of cores (>98% core recovery) indicates that the hydrothermal system may be centered in the 4-km-diameter Chupadero Crater, which has been proposed as the source of pyroxene pumice deposits in the Tecuamburro area. TCB-1 is located 300 m south of a 300-m-diameter phreatic crater, Laguna Ixpaco; the core hole penetrates the thin edge of a tuff ring surrounding Ixpaco and zones of hydrothermal brecciation within the upper 150 m may be related to the phreatic blast, dated at 2,910 {sup 14}C years. At the time of this writing, the unequilibrated temperature at a depth of 570m was 180{degree}C. Data on fracturing, permeability, hydrothermal alteration, and temperature will be presented. 3 refs., 3 figs.

  19. Dynamic Graphics in a GIS: A Bidirectional Link between ArcView 2.0TM and XGobi

    E-Print Network [OSTI]

    Symanzik, Jrgen

    Dynamic Graphics in a GIS: A Bidirectional Link between ArcView 2.0TM and XGobi Jurgen Symanzik1 GIS Support and Research Facility, Iowa State University symanzik@iastate.edu Abstract. In Symanzik et al. 1994 we have presented a link between a Geographic Information System GIS, ARC INFOTM

  20. Dynamic Graphics in a GIS: A Bidirectional Link between ArcView 2.0 TM and XGobi

    E-Print Network [OSTI]

    Symanzik, Jrgen

    Dynamic Graphics in a GIS: A Bidirectional Link between ArcView 2.0 TM and XGobi Jurgen Symanzik 1 2 GIS Support and Research Facility, Iowa State University symanzik@iastate.edu Abstract. In Symanzik et al. (1994) we have presented a link between a Geographic Information System (GIS), ARC/INFO TM

  1. IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. PS-8, NO. 4, DECEMBER 1980 Behavior of a High Current Vacuum Arc Between

    E-Print Network [OSTI]

    Jerby, Eli

    IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. PS-8, NO. 4, DECEMBER 1980 Behavior of a High Current Vacuum Arc Between Hollow Cylindrical Electrodes in a Radial Magnetic Field RAYMOND L. BOXMAN, SENIOR on the behavior 0 54mm of a high current vacuum arc on cylindrical electrodes in a radial mag- 15mm netic field

  2. Advanced plasma flow simulations of cathodic-arc and ferroelectric plasma sources for neutralized drift compression experiments

    E-Print Network [OSTI]

    Gilson, Erik

    Advanced plasma flow simulations of cathodic-arc and ferroelectric plasma sources for neutralized cathodic-arc plasma source show the coupling efficiency of the plasma flow from the source to the drift drift compression experiments Adam B. Sefkow, Ronald C. Davidson, and Erik P. Gilson Plasma Physics

  3. Accelerated Life Testing of PV Arc-Fault Detectors Jay Johnson, Michael Neilsen, Paul Vianco, N. Rob Sorensen,

    E-Print Network [OSTI]

    interrupters (AFCIs) to be incorporated into photovoltaic (PV) systems to prevent fires. Some manufacturers-fault prevention devices. Index Terms -- photovoltaic systems, arc-fault detectors, accelerated life testing on the photovoltaic (PV) system. While there has been extensive work to create functionally robust arc-fault detectors

  4. Instability of a Vacuum Arc Centrifuge M. J. Hole, R. S. Dallaqua, S. W. Simpson* and E. Del Bosco.

    E-Print Network [OSTI]

    Instability of a Vacuum Arc Centrifuge M. J. Hole, R. S. Dallaqua, S. W. Simpson* and E. Del Bosco, SP, Brazil Abstract. Ever since conception of the Vacuum Arc Centrifuge (VAC) in 1980, periodic predictions and compare with detailed experiments conducted on the PCEN centrifuge at the Brazilian National

  5. The red triangles are volcano locations. Dark-orange areas have a higher volcanic hazard; light-orange areas have a lower volcanic hazard. Dark-gray areas have a higher ash fall hazard;

    E-Print Network [OSTI]

    The red triangles are volcano locations. Dark-orange areas have a higher volcanic hazard; light-orange areas have a lower volcanic hazard. Dark-gray areas have a higher ash fall hazard; light-gray areas have years. Mauna Loa, in Hawaii, is the world's largest active volcano. The Cascade Range--home to more

  6. Tkalcic, H., D.S. Dreger, G.R. Foulger, B.R. Julian, A. Fichtner, A seismological portrait of the anomalous 1996 Bardarbunga volcano, Iceland, earthquake (invited poster), EOS Trans. AGU, Fall Meet. Suppl.,

    E-Print Network [OSTI]

    Foulger, G. R.

    of the anomalous 1996 Bardarbunga volcano, Iceland, earthquake (invited poster), EOS Trans. AGU, Fall Meet. Suppl., Abstract S21B-1710, 2009. A Seismological Portrait of the Anomalous 1996 Bardarbunga Volcano, Iceland was recorded well by the regional-scale Iceland Hotspot Project seismic experiment. Several hypotheses were

  7. Linking ArcView 3.0TM and XGobi: Insight Behind the Front End

    E-Print Network [OSTI]

    Symanzik, Jrgen

    of the implementation of a bidirectional link between the Geographic Information System GIS ArcView 3.0TM; Geographic information system; Imple- mentation issues; Spatial cumulative distribution function; Spatial statistics; Spatially lagged scatterplot; Variogram cloud plot. 1 Introduction Geographic Information Systems

  8. Linking ArcView 3.0TM and XGobi: Insight Behind the Front End

    E-Print Network [OSTI]

    Symanzik, Jrgen

    of a bidirectional link between the Geographic Information System (GIS) ArcView 3.0TM and the interactive dynamic Information Systems (GISs) are used extensively for examining spa- tial data but, traditionally, they have few tools necessary for displaying geographic information. The lack of ex- ploratory tools in a GIS

  9. CHANGES IN SOLIDIFICATION MODE, AND THE MEASUREMENT OF COOLING RATES FOLLOWING SOLIDIFICATION DURING ARC WELDING

    E-Print Network [OSTI]

    Cambridge, University of

    SOLIDIFICATION DURING ARC WELDING 2.1 INTRODUCTION The solidification process in a weld pool has been shown to have a considerable in- fluence upon the properties of the resultant weld. It influences elements, and hence the homogeneity of the weld. Previous work on the cooling behaviour of welds (Garland

  10. Improved Microstructure and Properties of 6061 Aluminum Alloy Weldments Using a Double-Sided Arc Welding

    E-Print Network [OSTI]

    Zhang, YuMing

    Welding Process Y.M. ZHANG, C. PAN, and A.T. MALE Due to its popularity and high crack sensitivity, 6061 aluminum alloy was selected as a test material for the newly developed double-sided arc welding (DSAW systematically. The percentage of fine equiaxed grains in the fully penetrated welds is greatly increased

  11. Computational Modeling of Microstructural-Evolution in AISI 1005 Steel During Gas Metal Arc Butt Welding

    E-Print Network [OSTI]

    Grujicic, Mica

    Welding M. Grujicic, S. Ramaswami, J.S. Snipes, R. Yavari, A. Arakere, C.-F. Yen, and B.A. Cheeseman-mechanical finite-element procedure is developed to model conventional gas metal arc welding (GMAW) butt of the workpiece and the weld temperature- dependent and by allowing the potential work of plastic deformation

  12. GIS Fundamentals: Introduction to GIS Lesson 3, Digitizing Lesson 3: Digitizing in ArcMap

    E-Print Network [OSTI]

    Butler, Christopher J.

    GIS Fundamentals: Introduction to GIS Lesson 3, Digitizing Lesson 3: Digitizing in ArcMap What You Chapter 4 in the GIS Fundamentals textbook before starting this lab, as the chapter covers the basics on how the photo was taken (flying height, terrain, camera tilt, and other factors). GIS data

  13. Arc Fault Risk Assessment and Degradation Model Development for Photovoltaic Connectors

    E-Print Network [OSTI]

    Arc Fault Risk Assessment and Degradation Model Development for Photovoltaic Connectors Benjamin B of photovoltaic installations information necessary to develop a data-driven plan for BOS connector maintenance, reliability I. INTRODUCTION As the reliability of traditional photovoltaic (PV) modules becomes better

  14. www.esri.com ArcUser Fall 2010 7 Continued on page 8

    E-Print Network [OSTI]

    Wright, Dawn Jeannine

    Answering Real-World An antiaircraft gun point feature has been symbolized as two threat dome layers by the visibility volume for the antiaircraft gun. #12;8 ArcUser Fall 2010 www.esri.com Some geographic questions.Thisisaninherently3Dprob- lem, because the ranges calculated for weapons are often based on direct 3D distances

  15. UWB radar technique for arc detection in coaxial cables and waveguides

    SciTech Connect (OSTI)

    Maggiora, R.; Salvador, S.

    2009-11-26

    As spread spectrum technology has revolutionized the communications industry, Ultra Wide Band (UWB) technology is dramatically improving radar performances. These advanced signal processing techniques have been adapted to coaxial cables and waveguides to provide new features and enhanced performance on arc detection. UWB signals constituted by a sequence of chips (properly chosen to reduce side lobes and to improve detection accuracy) are transmitted along the transmission lines at a specified Pulse Repetition Frequency (PRF) and their echoes are received by means of directional couplers. The core of the receiver is an ultra high-speed correlator implemented in a Digital Signal Processor (DSP). When a target (arc) is detected, its position and its 'radar cross section' are calculated to be able to provide the arc position along the transmission line and to be able to classify the type of detected arc. The 'background scattering' is routinely extracted from the received signal at any pulse. This permits to be resilient to the background structure of transmission lines (bends, junctions, windows, etc.). Thanks to the localization feature, segmentation is also possible for creating sensed and non-sensed zones (for example, to be insensitive to antenna load variations)

  16. A Summary of Recent Experimental Research on Ion Energy and Charge States of Pulsed Vacuum Arcs

    SciTech Connect (OSTI)

    Oks, Efim M.; Yushkov, Georgy Yu.; Anders, Andre

    2008-06-16

    The paper reviews the results of vacuum arc experimental investigations made collaboratively by research groups from Berkeley and Tomsk over the last two years, i.e. since the last ISDEIV in 2006. Vacuum arc plasma of various metals was produced in pulses of a few hundred microseconds duration, and the research focussed on three topics: (i) the energy distribution functions for different ion charge states, (ii) the temporal development of the ion charge state distribution, and (iii) the evolution of the mean directed ion velocities during plasma expansion. A combined quadruple mass-to-charge and energy ana-lyzer (EQP by HIDEN Ltd) and a time-of-flight spectrometer were employed. Cross-checking data by those complimen-tary techniques helped to avoid possible pitfalls in interpre-tation. It was found that the ion energy distribution func-tions in the plasma were independent of the ion charge state, which implies that the energy distribution on a substrate are not equal to due to acceleration in the substrate's sheath. In pulsed arc mode, the individual ion charge states fractions showed changes leading to a decrease of the mean charge state toward a steady-state value. This decrease can be re-duced by lower arc current, higher pulse repetition rate and reduced length of the discharge gap. It was also found that the directed ion velocity slightly decreased as the plasma expanded into vacuum.

  17. High current multicharged metal ion source using high power gyrotron heating of vacuum arc plasma

    SciTech Connect (OSTI)

    Vodopyanov, A. V.; Golubev, S. V.; Khizhnyak, V. I.; Mansfeld, D. A.; Nikolaev, A. G.; Oks, E. M.; Savkin, K. P.; Vizir, A. V.; Yushkov, G. Yu.

    2008-02-15

    A high current, multi charged, metal ion source using electron heating of vacuum arc plasma by high power gyrotron radiation has been developed. The plasma is confined in a simple mirror trap with peak magnetic field in the plug up to 2.5 T, mirror ratio of 3-5, and length variable from 15 to 20 cm. Plasma formed by a cathodic vacuum arc is injected into the trap either (i) axially using a compact vacuum arc plasma gun located on axis outside the mirror trap region or (ii) radially using four plasma guns surrounding the trap at midplane. Microwave heating of the mirror-confined, vacuum arc plasma is accomplished by gyrotron microwave radiation of frequency 75 GHz, power up to 200 kW, and pulse duration up to 150 {mu}s, leading to additional stripping of metal ions by electron impact. Pulsed beams of platinum ions with charge state up to 10+, a mean charge state over 6+, and total (all charge states) beam current of a few hundred milliamperes have been formed.

  18. Effects of induced flow on the depths of active back-arc basins

    E-Print Network [OSTI]

    Tomlins, Robynn Lee

    1993-01-01

    The depth of active back-arc basins, younger than 10 Ma is correlated to the angle of subduction, in that the deepest basins are associated with steep angles of subduction, and the shallowest to small angles of subduction. A two-dimensional comer...

  19. A static voltage-current characteristic for the low current DC arc

    E-Print Network [OSTI]

    Moores, Gregory Lee

    1998-01-01

    on bare I8AWG solid copper electrodes in geometries simulating Sow current arcs, between wires of a typical cable bundle (1-6 amps and 12-125mils long). Using multiple linear regression the data was fitted to 18 different models, new or proposed...

  20. ARC Collaborative Research Seminar Series September 16th, Thursday (1:30-3:00pm)

    E-Print Network [OSTI]

    Papalambros, Panos

    Alternative Energy/Power Systems Anna Stefanopoulou and Jeff Stein, University of Michigan (click here, GM Room ARC Collaborative Research Seminar Series #12;Presented by Thrust Area 2: Modeling Vehicle.Professor, U. of Michigan Overview of Bio-dynamic Modeling of Vehicle-Operator Systems Wade Allen, Technical

  1. The Magnetite Crisis in the Evolution of Arc-related Magmas and the Initial

    E-Print Network [OSTI]

    Lee, Cin-Ty Aeolus

    and back-arc magma series is their association with ores of the rare, but economically important metals Au of these metals is not straightforward. For Au, one of the rarest metals on Earth, with a primitive mantle RESEARCH SCHOOL OF EARTH SCIENCES, AUSTRALIAN NATIONAL UNIVERSITY, CANBERRA, ACT 0200, AUSTRALIA RECEIVED

  2. Discovery of Red Selected Arcs at z=4.04 behind Abell 2390

    E-Print Network [OSTI]

    Brenda Frye; Tom Broadhurst

    1997-12-08

    We describe the properties of a system of red arcs discovered at z=4.04 around the cluster A2390 ($z=0.23$). These arcs are images of a single galaxy, where the lensing is compounded by an elliptical cluster member lying close to the critical curve of the cluster. The combined magnification is estimated to be $\\sim 20$, using HST images, depending the gradient of the model potentials, implying an unlensed magnitude for the source of $I_{AB}=25.5$. Keck spectroscopy reveals a continuum well fitted by B-stars and attenuated by the Lyman-series forest with an opacity consistent with z$\\sim$4 QSO spectra, making the arcs relatively red. Damped Ly$\\alpha$ absorption is observed at the source redshift with a relatively high column, n$_{HI}=3\\times 10^{21}$. Curiously, Ly$\\alpha$ emission is spatially separated ($\\sim 0.5$kpc) from the bright stellar continuum and lies $\\sim$ 300Km/s redward of interstellar absorption lines at z=4.04. Similar redwardl of young galaxies. Finally, we briefly comment on the notorious ``straight arc'' in A2390, which is resolved into two unrelated galaxies at z=0.913 and z=1.033.

  3. (Smart) Look-Ahead Arc Consistency and the Pursuit of CSP Tractability

    E-Print Network [OSTI]

    Dalmau, Victor

    (Smart) Look-Ahead Arc Consistency and the Pursuit of CSP Tractability Hubie Chen 1 and V#19. The constraint satisfaction problem (CSP) can be formu- lated as the problem of deciding, given a pair (A; B) of relational struc- tures, whether or not there is a homomorphism from A to B. Although the CSP is in general

  4. U^Pb geochronology of Seychelles granitoids: a Neoproterozoic continental arc fragment

    E-Print Network [OSTI]

    Torsvik, Trond Helge

    U^Pb geochronology of Seychelles granitoids: a Neoproterozoic continental arc fragment R.D. Tucker reserved. Keywords: U/Pb; geochronology; Neoproterozoic; magmatism; Rodinia; reconstruction; Seychelles 1 of these rocks was rst established [2^4]. Since then, numerous geochronological studies of Sey- chelles

  5. Archived as condmat/yymmnnn and mp arc yynnn Preprint CPTXXX98 Rigidity of interfaces

    E-Print Network [OSTI]

    Archived as cond­mat/yymmnnn and mp arc yy­nnn Preprint CPT­XXX­98 Rigidity of interfaces) Dedicated to the memory of Roland Dobrushin Abstract We analyze the thermodynamic properties of interfaces that the 100 interface in this model, at half­filling, is rigid, as in the three­dimensional Ising model

  6. 10/3/08 10:11 AMBiden energizes crowd at ARC Page 1 of 3http://columbiatribune.com/2008/sep/20080909news004.asp

    E-Print Network [OSTI]

    Glaser, Rainer

    10/3/08 10:11 AMBiden energizes crowd at ARC Page 1 of 3http://columbiatribune.com/2008/sep Sports Forum Biden energizes crowd at ARC VP nominee criticizes McCain-Palin. By JASON ROSENBAUM used last week's #12;10/3/08 10:11 AMBiden energizes crowd at ARC Page 2 of 3http

  7. An interferometric and spectroscopic argon arc plasma diagnostic This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-Print Network [OSTI]

    An interferometric and spectroscopic argon arc plasma diagnostic This article has been downloaded An interferometric and spectroscopic argon arc plasma diagnostic K MusioltS, A Czernichowskit, J ChapelleS and C de diagnostics of an arc plasma, when the halfwidth of the Balmer H, line is measured, there is a certain amount

  8. Structurally Integrated Coatings for Wear and Corrosion (SICWC): Arc Lamp, InfraRed (IR) Thermal Processing

    SciTech Connect (OSTI)

    Mackiewicz-Ludtka, G.; Sebright, J.

    2007-12-15

    The primary goal of this Cooperative Research and Development Agreement (CRADA) betwe1311 UT-Battelle (Contractor) and Caterpillar Inc. (Participant) was to develop the plasma arc lamp (PAL), infrared (IR) thermal processing technology 1.) to enhance surface coating performance by improving the interfacial bond strength between selected coatings and substrates; and 2.) to extend this technology base for transitioning of the arc lamp processing to the industrial Participant. Completion of the following three key technical tasks (described below) was necessary in order to accomplish this goal. First, thermophysical property data sets were successfully determined for composite coatings applied to 1010 steel substrates, with a more limited data set successfully measured for free-standing coatings. These data are necessary for the computer modeling simulations and parametric studies to; A.) simulate PAL IR processing, facilitating the development of the initial processing parameters; and B.) help develop a better understanding of the basic PAL IR fusing process fundamentals, including predicting the influence of melt pool stirring and heat tnmsfar characteristics introduced during plasma arc lamp infrared (IR) processing; Second, a methodology and a set of procedures were successfully developed and the plasma arc lamp (PAL) power profiles were successfully mapped as a function of PAL power level for the ORNL PAL. The latter data also are necessary input for the computer model to accurately simulate PAL processing during process modeling simulations, and to facilitate a better understand of the fusing process fundamentals. Third, several computer modeling codes have been evaluated as to their capabilities and accuracy in being able to capture and simulate convective mixing that may occur during PAL thermal processing. The results from these evaluation efforts are summarized in this report. The intention of this project was to extend the technology base and provide for transitioning of the arc lamp processing to the industrial Participant.

  9. SCALED ELECTRON MODEL OF A DOGBONE MUON RLA WITH MULTI-PASS ARCS

    SciTech Connect (OSTI)

    Kevin Beard, Rolland Johnson, Vasiliy Morozov, Yves Roblin, Andrew Hutton, Geoffrey Krafft, Slawomir Bogacz

    2012-07-01

    The design of a dogbone RLA with linear-field multi-pass arcs was earlier developed for accelerating muons in a Neutrino Factory and a Muon Collider. It allows for efficient use of expensive RF while the multi-pass arc design based on linear combined-function magnets exhibits a number of advantages over separate-arc or pulsed-arc designs. Such an RLA may have applications going beyond muon acceleration. This paper describes a possible straightforward test of this concept by scaling a GeV scale muon design for electrons. Scaling muon momenta by the muon-to-electron mass ratio leads to a scheme, in which a 4.5 MeV electron beam is injected at the middle of a 3 MeV/pass linac with two double-pass return arcs and is accelerated to 18 MeV in 4.5 passes. All spatial dimensions including the orbit distortion are scaled by a factor of 7.5, which arises from scaling the 200 MHz muon RF to a readily available at CEBAF 1.5 GHz. The footprint of a complete RLA fits in an area of 25 by 7 m. The scheme utilizes only fixed magnetic fields including injection and extraction. The hardware requirements are not very demanding, making it straightforward to implement. In this report, we have shown first of all that measuring the energy spectrum of the fast neutrons in the liquid scintillators allows one to distinguish the two chemical forms of plutonium. In addition, combining this information with the Feynman 2-neutron and 3-neutron correlations allows one to extract the {alpha}-ratio without explicitly knowing the multiplication. Given the {alpha}-ratio one can then extract the multiplication as well as the {sup 239}Pu and {sup 240}Pu masses directly from the moment equations.

  10. DESERT PAVEMENTS AND SOILS ON BASALTIC PYROCLASTIC DEPOSITS AT LATHROP WELLS AND RED CONE VOLCANOES, SOUTHERN NEVADA

    SciTech Connect (OSTI)

    G.A. Valentine; C.D. Harrington

    2005-08-10

    Formation of desert pavement and accretionary soils are intimately linked in arid environments such as the Mojave Desert. Well-sorted fallout scoria lapilli at Lathrop Wells (75-80 ky) and Red Cone ({approx}1 Ma) volcanoes (southern Nevada) formed an excellent starting material for pavement, allowing infiltration of eolian silt and fine sand that first clogs the pore space of underlying tephra and then aggrades and develops vesicular A (Av) horizons. Variations in original pyroclast sizes provide insight into minimum and maximum clast sizes that promote pavement and soil formation: pavement becomes ineffective when clasts can saltate under the strongest winds, while clasts larger than coarse lapilli are unable to form an interlocking pavement that promotes silt accumulation (necessary for Av development). Contrary to predictions that all pavements above altitudes of {approx}400 m would have been ''reset'' in their development after late Pleistocene vegetation advances (about 15 ka), the soils and pavements show clear differences in maturity between the two volcanoes. This indicates that either the pavement soils develop slowly over many 10,000's of years and then are very stable, or that, if they are disrupted by vegetation advances, subsequent pavements are reestablished with successively more mature characteristics.

  11. How Common are Noise Sources on the Crash Arc of Malaysian Flight 370

    SciTech Connect (OSTI)

    Fenimore, Edward E.; Kunkle, Thomas David; Stead, Richard J.

    2014-10-21

    Malaysian Flight 370 disappeared nearly without a trace. Besides some communication handshakes to the INMASAT satellite, the Comprehensive Test Ban Treaty monitoring system could have heard the aircraft crash into the southern Indian Ocean. One noise event from Cape Leeuwin has been suggested by Stead as the crash and occurs within the crash location suggested by Kunkle at el. We analyze the hydrophone data from Cape Leeuwin to understand how common such noise events are on the arc of possible locations where Malaysian Flight 370 might have crashed. Few other noise sources were found on the arc. The noise event found by Stead is the strongest. No noise events are seen within the Australian Transportation Safety Board (ATSB) new search location until the 10th strongest event, an event which is very close to the noise level.

  12. A review comparing cathodic arcs and high power impulse magnetron sputtering (HiPIMS)

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

    Anders, Andre

    2014-10-01

    High power impulse magnetron sputtering (HiPIMS) has been in the center of attention over the last years as it is an emerging physical vapor deposition (PVD) technology that combines advantages of magnetron sputtering with various forms of energetic deposition of films such as ion plating and cathodic arc plasma deposition. It should not come at a surprise that many extension and variations of HiPIMS make use, intentionally or unintentionally, of previously discovered approaches to film processing such as substrate surface preparation by metal ion sputtering and phased biasing for film texture and stress control. Therefore, in this review, an overview is given on some historical developments and features of cathodic arc and HiPIMS plasmas, showing commonalities and differences. To limit the scope, emphasis is put on plasma properties, as opposed to surveying the vast literature on specific film materials and their properties.

  13. Use of vacuum arc plasma guns for a metal puff Z-pinch system

    SciTech Connect (OSTI)

    Rousskikh, A. G.; Zhigalin, A. S.; Oreshkin, V. I.; Chaikovsky, S. A.; Labetskaya, N. A.; Baksht, R. B.

    2011-09-15

    The performance of a metal puff Z-pinch system has been studied experimentally. In this type of system, the initial cylindrical shell 4 cm in diameter was produced by ten plasma guns. Each gun initiates a vacuum arc operating between magnesium electrodes. The net current of the guns was 80 kA. The arc-produced plasma shell was compressed by using a 450-kA, 450-ns driver, and as a result, a plasma column 0.3 cm in diameter was formed. The electron temperature of the plasma reached 400 eV at an average ion concentration of 1.85 {center_dot} 10{sup 18} cm{sup -3}. The power of the Mg K-line radiation emitted by the plasma for 15-30 ns was 300 MW/cm.

  14. Ion Species and Charge States of Vacuum Arc Plasma with Gas Feed and Longitudinal Magnetic Field

    SciTech Connect (OSTI)

    Oks, Efim; Anders, Andre

    2010-06-23

    The evolution of copper ion species and charge state distributions is measured for a long vacuum arc discharge plasma operated in the presence of a longitudinal magnetic field of several 10 mT and working gas (Ar). It was found that changing the cathode-anode distance within 20 cm as well as increasing the gas pressure did not affect the arc burning voltage and power dissipation by much. In contrast, burning voltage and power dissipation were greatly increased as the magnetic field was increased. The longer the discharge gap the greater was the fraction of gaseous ions and the lower the fraction of metal ions, while the mean ion charge state was reduced. It is argued that the results are affected by charge exchange collisions and electron impact ionization.

  15. Graphene layer growth on silicon substrates with nickel film by pulse arc plasma deposition

    SciTech Connect (OSTI)

    Fujita, K.; Banno, K.; Aryal, H. R.; Egawa, T.

    2012-10-15

    Carbon layer has been grown on a Ni/SiO{sub 2}/Si(111) substrate under high vacuum pressure by pulse arc plasma deposition. From the results of Raman spectroscopy for the sample, it is found that graphene was formed by ex-situ annealing of sample grown at room temperature. Furthermore, for the sample grown at high temperature, graphene formation was shown and optimum temperature was around 1000 Degree-Sign C. Transmission electron microscopy observation of the sample suggests that the graphene was grown from step site caused by grain of Ni film. The results show that the pulse arc plasma technique has the possibility for acquiring homogenous graphene layer with controlled layer thickness.

  16. Measurements of the Ion Species of Cathodic Arc Plasma in an Axial Magnetic Field

    SciTech Connect (OSTI)

    Oks, Efim; Anders, Andre

    2010-10-19

    Metal and gas ion species and their charge state distributions were measured for pulsed copper cathodic arcs in argon background gas in the presence of an axial magnetic field. It was found that changing the cathode position relative to anode and ion extraction system as well as increasing the gas pressure did not much affect the arc burning voltage and the related power dissipation. However, the burning voltage and power dissipation greatly increased as the magnetic field strength was increased. The fraction of metal ions and the mean ion charge state were reduced as the discharge length was increased. The observations can be explained by the combination of charge exchange collisions and electron impact ionization. They confirm that previously published data on characteristic material-dependent charge state distributions (e.g., Anders and Yushkov, J. Appl. Phys., Vol. 91, pp. 4824-4832, 2002) are not universal but valid for high vacuum conditions and the specifics of the applied magnetic fields.

  17. Schlieren technique applied to the arc temperature measurement in a high energy density cutting torch

    SciTech Connect (OSTI)

    Prevosto, L.; Mancinelli, B.; Artana, G.; Kelly, H.

    2010-01-15

    Plasma temperature and radial density profiles of the plasma species in a high energy density cutting arc have been obtained by using a quantitative schlieren technique. A Z-type two-mirror schlieren system was used in this research. Due to its great sensibility such technique allows measuring plasma composition and temperature from the arc axis to the surrounding medium by processing the gray-level contrast values of digital schlieren images recorded at the observation plane for a given position of a transverse knife located at the exit focal plane of the system. The technique has provided a good visualization of the plasma flow emerging from the nozzle and its interactions with the surrounding medium and the anode. The obtained temperature values are in good agreement with those values previously obtained by the authors on the same torch using Langmuir probes.

  18. Order Reduction of the Radiative Heat Transfer Model for the Simulation of Plasma Arcs

    E-Print Network [OSTI]

    Fagiano, Lorenzo

    2015-01-01

    An approach to derive low-complexity models describing thermal radiation for the sake of simulating the behavior of electric arcs in switchgear systems is presented. The idea is to approximate the (high dimensional) full-order equations, modeling the propagation of the radiated intensity in space, with a model of much lower dimension, whose parameters are identified by means of nonlinear system identification techniques. The low-order model preserves the main structural aspects of the full-order one, and its parameters can be straightforwardly used in arc simulation tools based on computational fluid dynamics. In particular, the model parameters can be used together with the common approaches to resolve radiation in magnetohydrodynamic simulations, including the discrete-ordinate method, the P-N methods and photohydrodynamics. The proposed order reduction approach is able to systematically compute the partitioning of the electromagnetic spectrum in frequency bands, and the related absorption coefficients, tha...

  19. Plasma chemistry fluctuations in a reactive arc plasma in the presence of magnetic fields

    SciTech Connect (OSTI)

    Rosen, J.; Anders, A.; Schneider, J.M.

    2002-01-13

    The effect of a magnetic field on the plasma chemistry and pulse-to-pulse fluctuations of cathodic arc ion charge state distributions in a reactive environment were investigated. The plasma composition was measured by time-of-flight charge-to-mass spectrometry. The fluctuation of the concentrations of Al+, Al2+ and Al3+ was found to increase with an increasing magnetic field strength. We suggest that this is caused by magnetic field dependent fluctuations of the energy input into cathode spots as seen through fluctuations of the cathode potential. These results are qualitatively consistent with the model of partial local Saha equilibrium and are of fundamental importance for the evolution of the structure of films deposited by reactive cathodic arc deposition.

  20. Tomographic interferometry of a filtered high-current vacuum arc plasma

    SciTech Connect (OSTI)

    Warr, George B.; Tarrant, Richard N.; Bilek, Marcela M. M.; McKenzie, David R.; Harris, Jeffrey H.; Howard, John; Blackwell, Boyd D.

    2007-04-01

    Tomography of a plasma enables the distribution of electron density to be visualized. We report on the design of two tomographic interferometer systems used to measure plasma electron density distributions in a high-current pulsed cathodic vacuum arc. The method is shown to be capable of microsecond time resolution. The spatial resolution of the quasioptical interferometer operating at 2 mm wavelength is 20 mm and the spatial resolution of the waveguide-based interferometer operating at 8 mm wavelength is 50 mm. In both cases the resolution achieved depends on the launching and receiving geometries. We developed criteria for assessing the tomogram for artifacts arising from limited sampling. First results of the spatial and temporal history of plasma in a high-current vacuum arc guided by a curved magnetic filter are presented and indicate poloidal field fluctuations reminiscent of magnetohydrodynamic instabilities in pinches. The applicability of the tomographic interferometry method to optimize plasma transport through the filter is also demonstrated.

  1. Mechanism of surface modification in the plasma-surface interaction in electrical arcs

    E-Print Network [OSTI]

    Timko, H; Nordlund, K; Costelle, L; Matyash, K; Schneider, R; Toerklep, A; Arnau-Izquierdo, G; Descoeudres, A; Calatroni, S; Taborelli, M; Wuensch, W

    2010-01-01

    Electrical sparks and arcs are plasma discharges that carry large currents and can strongly modify surfaces. This damage usually comes in the form of micrometer-sized craters and frozen-in liquid on the surface. Using a combination of experiments, plasma and atomistic simulation tools, we now show that the observed formation of deep craters and liquidlike features during sparking in vacuum is explained by the impacts of energetic ions, accelerated under the given conditions in the plasma sheath to kiloelectron volt energies, on surfaces. The flux in arcs is so high that in combination with kiloelectron volt energies it produces multiple overlapping heat spikes, which can lead to cratering even in materials such as Cu, where a single heat spike normally does not.

  2. Mechanism of surface modification in the plasma surface interaction in electrical arcs

    E-Print Network [OSTI]

    Timko, Helga; Djurabekova, Flyura; Nordlund, Kai; Matyash, Konstantin; Schneider, Ralf; Toerklep, Anders; Arnau-Izquierdo, Gonzalo; Descoeudres, Antoine; Calatroni, Sergio; Taborelli, Mauro; Wuensch, Walter

    2010-01-01

    Electrical sparks and arcs are plasma discharges that carry large currents and can strongly modify surfaces. This damage usually comes in the form of micrometer-sized craters and frozen-in liquid on the surface. Using a combination of experiments, plasma and atomistic simulation tools, we now show that the observed formation of deep craters and liquidlike features during sparking in vacuum is explained by the impacts of energetic ions, accelerated under the given conditions in the plasma sheath to kiloelectron volt energies, on surfaces. The flux in arcs is so high that in combination with kiloelectron volt energies it produces multiple overlapping heat spikes, which can lead to cratering even in materials such as Cu, where a single heat spike normally does not.

  3. Transparent and conductive indium doped cadmium oxide thin films prepared by pulsed filtered cathodic arc deposition

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

    Zhu, Yuankun; Mendelsberg, Rueben J.; Zhu, Jiaqi; Han, Jiecai; Anders, Andr

    2012-11-26

    Indium doped cadmium oxide (CdO:In) films with different In concentrations were prepared on low-cost glass substrates by pulsed filtered cathodic arc deposition (PFCAD). In this study, it is shown that polycrystalline CdO:In films with smooth surface and dense structure are obtained. In-doping introduces extra electrons leading to remarkable improvements of electron mobility and conductivity, as well as improvement in the optical transmittance due to the Burstein Moss effect. CdO:In films on glass substrates with thickness near 230 nm show low resistivity of 7.23 x 10-5 ?cm, high electron mobility of 142 cm2/Vs, and mean transmittance over 80% from 500-1250 nmmore(including the glass substrate). These high quality pulsed arc-grown CdO:In films are potentially suitable for high efficiency multi-junction solar cells that harvest a broad range of the solar spectrum.less

  4. Transparent and conductive indium doped cadmium oxide thin films prepared by pulsed filtered cathodic arc deposition

    SciTech Connect (OSTI)

    Zhu, Yuankun; Mendelsberg, Rueben J.; Zhu, Jiaqi; Han, Jiecai; Anders, Andr

    2012-11-26

    Indium doped cadmium oxide (CdO:In) films with different In concentrations were prepared on low-cost glass substrates by pulsed filtered cathodic arc deposition (PFCAD). In this study, it is shown that polycrystalline CdO:In films with smooth surface and dense structure are obtained. In-doping introduces extra electrons leading to remarkable improvements of electron mobility and conductivity, as well as improvement in the optical transmittance due to the Burstein Moss effect. CdO:In films on glass substrates with thickness near 230 nm show low resistivity of 7.23 x 10-5 ?cm, high electron mobility of 142 cm2/Vs, and mean transmittance over 80% from 500-1250 nm (including the glass substrate). These high quality pulsed arc-grown CdO:In films are potentially suitable for high efficiency multi-junction solar cells that harvest a broad range of the solar spectrum.

  5. A review comparing cathodic arcs and high power impulse magnetron sputtering (HiPIMS)

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

    Anders, Andr

    2014-09-02

    In this study, high power impulse magnetron sputtering (HiPIMS) has been in the center of attention over the last years as it is an emerging physical vapor deposition (PVD) technology that combines advantages of magnetron sputtering with various forms of energetic deposition of films such as ion plating and cathodic arc plasma deposition. It should not come at a surprise that many extension and variations of HiPIMS make use, intentionally or unintentionally, of previously discovered approaches to film processing such as substrate surface preparation by metal ion sputtering and phased biasing for film texture and stress control. Therefore, in thismorereview, an overview is given on some historical developments and features of cathodic arc and HiPIMS plasmas, showing commonalities and differences. To limit the scope, emphasis is put on plasma properties, as opposed to surveying the vast literature on specific film materials and their properties.less

  6. On the long-term correlations and multifractal properties of electric arc furnace time series

    E-Print Network [OSTI]

    Livi, Lorenzo; Rizzi, Antonello; Sadeghian, Alireza

    2015-01-01

    In this paper, we study long-term correlations and multifractal properties elaborated from time series of three-phase current signals coming from an industrial electric arc furnace plant. Implicit sinusoidal trends are suitably detected in the scaling of the fluctuation function of such time series. Time series are then initially filtered via a Fourier based analysis, removing hence such strong periodicities. In the filtered time series we detected long-term, positive correlations. The presence of persistent correlations is in agreement with the typical V--I characteristic (hysteresis) of the electric arc furnace, justifying thus the memory effects found in the current time series. The multifractal signature is strong enough in the filtered time series to be effectively classified as multifractal.

  7. Transparent and conductive indium doped cadmium oxide thin films prepared by pulsed filtered cathodic arc deposition

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

    Zhu, Yuankun [Harbin Institute of Technology (China). Center for Composite Materials and Structures; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Plasma Applications Group; Mendelsberg, Rueben J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Plasma Applications Group and Molecular Foundry; Zhu, Jiaqi [Harbin Institute of Technology (China). Center for Composite Materials and Structures; Han, Jiecai [Harbin Institute of Technology (China). Center for Composite Materials and Structures; Anders, Andre [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Plasma Applications Group

    2013-01-01

    Indium doped cadmium oxide (CdO:In) films with different In concentrations were prepared on low-cost glass substrates by pulsed filtered cathodic arc deposition (PFCAD). It is shown that polycrystalline CdO:In films with smooth surface and dense structure are obtained. In-doping introduces extra electrons leading to remarkable improvements of electron mobility and conductivity, as well as improvement in the optical transmittance due to the Burstein Moss effect. CdO:In films on glass substrates with thickness near 230 nm show low resistivity of 7.23 10-5 cm, high electron mobility of 142 cm2/Vs, and mean transmittance over 80percent from 500-1250 nm (including the glass substrate). These high quality pulsed arc-grown CdO:In films are potentially suitable for high efficiency multi-junction solar cells that harvest a broad range of the solar spectrum.

  8. Puzzling differences in bismuth and lead plasmas: evidence for the significant role of neutrals in cathodic vacuum arcs

    E-Print Network [OSTI]

    Anders, Andre; Yushkov, Georgy Yu.

    2007-01-01

    vacuum arcs for (a) lead plasma, (b) bismuth plasma. Arcproperties 16,17,22 of lead and bismuth. Pb Bi Atomic numberdifferences in bismuth and lead plasmas: evidence for the

  9. Geochemical tracers of processes affecting the formation of seafloor hydrothermal fluids and deposits in the Manus back-arc basin

    E-Print Network [OSTI]

    Craddock, Paul R

    2009-01-01

    Systematic differences in trace element compositions (rare earth element (REE), heavy metal, metalloid concentrations) of seafloor vent fluids and related deposits from hydrothermal systems in the Manus back-arc basin ...

  10. AUTOMOTIVE RESEARCH CENTER (ARC) A U.S. Army Center of Excellence for Modeling and Simulation of Ground Vehicles

    E-Print Network [OSTI]

    Awtar, Shorya

    Vehicles AU T OM OT IVE RESEA RC H CEN T ER ARC Seminar Jet Fuel It's Not Just for Planes! Dr. Tim Edwards Senior Chemical Engineer Fuels Branch Air Abstract: Jet fuel is traditionally thought of as the fuel

  11. Development of an ArcGIS interface and design of a geodatabase for the soil and water assessment tool

    E-Print Network [OSTI]

    Valenzuela Zapata, Milver Alfredo

    2004-09-30

    This project presents the development and design of a comprehensive interface coupled with a geodatabase (ArcGISwat 2003), for the Soil and Water Assessment Tool (SWAT). SWAT is a hydrologically distributed, lumped parameter model that runs on a...

  12. Thermal protection of H13 steel by growth of (TiAl)N films by PAPVD pulsed arc technique

    SciTech Connect (OSTI)

    Jimenez, H.; Devia, D.M.; Benavides, V.; Devia, A. Arango, Y.C.; Arango, P.J.; Velez, J.M.

    2008-08-15

    (TiAl)N Films were grown on H13 steel by a plasma assisted repetitive pulsed arc discharge. To grow the coatings, a TiAl sintered cathode was used, 50% Ti-50% Al. The deposition system consists of a reaction chamber with two electrodes placed face to face. A pulsed power supply, which allows for control of parameters like time active arc, time between arcs, arc energy, and others, is used to generate the discharge. Thermal changes were carried out on H13 steel before and after growing the (TiAl)N films. X-ray diffraction (XRD) was employed to study the coatings, observing the H13 steel and (TiAl)N oxidation temperature. Morphological characteristics were analyzed by means of an Atomic Force Microscopy (AFM). Scanning electron microscopy (SEM) revealed the surface chemical composition of the films and morphological details of the samples.

  13. PSInSAR as a new tool to monitor preeruptive volcano ground deformation: Validation using GPS measurements on Piton de la

    E-Print Network [OSTI]

    Kaminski, Edouard

    : Validation using GPS measurements on Piton de la Fournaise A. Peltier,1 M. Bianchi,2 E. Kaminski,3 J over large areas. Citation: Peltier, A., M. Bianchi, E. Kaminski, J.C. Komorowski, A. Rucci, and T of the Piton de La Fournaise volcano (La Runion Island), with a mean of two eruptions per year [Peltier et al

  14. COVER A Classopollis meyeriana conifer pollen grain (~30 micrometers across) preserved in lake sediments deposited just after a massive, volcano-induced extinction event ~200 million years ago.

    E-Print Network [OSTI]

    Olsen, Paul E.

    sediments deposited just after a massive, volcano-induced extinction event ~200 million years ago rates required to induce major climate perturbations. Here, we present new zircon uranium-lead (U separation between LIP volcanic deposits and stratigraphic sequences preserving evidence of the extinction

  15. Control of Gas Tungsten Arc welding pool shape by trace element addition to the weld pool

    DOE Patents [OSTI]

    Heiple, C.R.; Burgardt, P.

    1984-03-13

    An improved process for Gas Tungsten Arc welding maximizes the depth/width ratio of the weld pool by adding a sufficient amount of a surface active element to insure inward fluid flow, resulting in deep, narrow welds. The process is especially useful to eliminate variable weld penetration and shape in GTA welding of steels and stainless steels, particularly by using a sulfur-doped weld wire in a cold wire feed technique.

  16. Miniature pulsed vacuum arc plasma gun and apparatus for thin-film fabrication

    DOE Patents [OSTI]

    Brown, I.G.; MacGill, R.A.; Galvin, J.E.; Ogletree, D.F.; Salmeron, M.

    1998-11-24

    A miniature (dime-size in cross-section) vapor vacuum arc plasma gun is described for use in an apparatus to produce thin films. Any conductive material can be layered as a film on virtually any substrate. Because the entire apparatus can easily be contained in a small vacuum chamber, multiple dissimilar layers can be applied without risk of additional contamination. The invention has special applications in semiconductor manufacturing. 8 figs.

  17. Miniature pulsed vacuum arc plasma gun and apparatus for thin-film fabrication

    DOE Patents [OSTI]

    Brown, Ian G. (Berkeley, CA); MacGill, Robert A. (Richmond, CA); Galvin, James E. (Emmeryville, CA); Ogletree, David F. (El Cerrito, CA); Salmeron, Miquel (El Cerrito, CA)

    1998-01-01

    A miniature (dime-size in cross-section) vapor vacuum arc plasma gun is described for use in an apparatus to produce thin films. Any conductive material can be layered as a film on virtually any substrate. Because the entire apparatus can easily be contained in a small vacuum chamber, multiple dissimilar layers can be applied without risk of additional contamination. The invention has special applications in semiconductor manufacturing.

  18. Exploring high temperature phenomena related to post-detonation using an electric arc

    SciTech Connect (OSTI)

    Dai, Z. R. Crowhurst, J. C.; Grant, C. D.; Knight, K. B.; Tang, V.; Chernov, A. A.; Cook, E. G.; Lotscher, J. P.; Hutcheon, I. D.

    2013-11-28

    We report a study of materials recovered from a uranium-containing plasma generated by an electric arc. The device used to generate the arc is capable of sustaining temperatures of an eV or higher for up to 100??s. Samples took the form of a 4??m-thick film deposited onto 8 pairs of 17??m-thick Cu electrodes supported on a 25??m-thick Kapton backing and sandwiched between glass plates. Materials recovered from the glass plates and around the electrode tips after passage of an arc were characterized using scanning and transmission electron microscopy. Recovered materials included a variety of crystalline compounds (e.g., UO{sub 2}, UC{sub 2}, UCu{sub 5},) as well as mixtures of uranium and amorphous glass. Most of the materials collected on the glass plates took the form of spherules having a wide range of diameters from tens of nanometers to tens of micrometers. The composition and size of the spherules depended on location, indicating different chemical and physical environments. A theoretical analysis we have carried out suggests that the submicron spherules presumably formed by deposition during the arc discharge, while at the same time the glass plates were strongly heated due to absorption of plasma radiation mainly by islands of deposited metals (Cu, U). The surface temperature of the glass plates is expected to have risen to ?2300?K thus producing a liquefied glass layer, likely diffusions of the deposited metals on the hot glass surface and into this layer were accompanied by chemical reactions that gave rise to the observed materials. These results, together with the compact scale and relatively low cost, suggest that the experimental technique provides a practical approach to investigate the complex physical and chemical processes that occur when actinide-containing material interacts with the environment at high temperature, for example, during fallout formation following a nuclear detonation.

  19. Analytical expression for the electric potential in the plasma sheath near an arc-cathode

    SciTech Connect (OSTI)

    Askari, S.; Minoo, H.

    2008-04-15

    An expression for the spatial dependence of the electric potential in a collisionless plasma sheath near an electron-emitting cathode is presented. The applicability of this expression for an arc cathode is demonstrated. Comparison with the numerical solutions of the model equations indicates that the sheath thickness and potential variation predicted by this expression are accurate in a wide range of the electron-emission yield.

  20. Solid oxide fuel cell processing using plasma arc spray deposition techniques. Final report

    SciTech Connect (OSTI)

    Ray, E.R.; Spengler, C.J.; Herman, H.

    1991-07-01

    The Westinghouse Electric Corporation, in conjunction with the Thermal Spray Laboratory of the State University of New York, Stony Brook, investigated the fabrication of a gas-tight interconnect layer on a tubular solid oxide fuel cell with plasma arc spray deposition. The principal objective was to determine the process variables for the plasma spray deposition of an interconnect with adequate electrical conductivity and other desired properties. Plasma arc spray deposition is a process where the coating material in powder form is heated to or above its melting temperature, while being accelerated by a carrier gas stream through a high power electric arc. The molten powder particles are directed at the substrate, and on impact, form a coating consisting of many layers of overlapping, thin, lenticular particles or splats. The variables investigated were gun power, spray distance, powder feed rate, plasma gas flow rates, number of gun passes, powder size distribution, injection angle of powder into the plasma plume, vacuum or atmospheric plasma spraying, and substrate heating. Typically, coatings produced by both systems showed bands of lanthanum rich material and cracking with the coating. Preheating the substrate reduced but did not eliminate internal coating cracking. A uniformly thick, dense, adherent interconnect of the desired chemistry was finally achieved with sufficient gas- tightness to allow fabrication of cells and samples for measurement of physical and electrical properties. A cell was tested successfully at 1000{degree}C for over 1,000 hours demonstrating the mechanical, electrical, and chemical stability of a plasma-arc sprayed interconnect layer.

  1. Solid oxide fuel cell processing using plasma arc spray deposition techniques

    SciTech Connect (OSTI)

    Ray, E.R.; Spengler, C.J.; Herman, H.

    1991-07-01

    The Westinghouse Electric Corporation, in conjunction with the Thermal Spray Laboratory of the State University of New York, Stony Brook, investigated the fabrication of a gas-tight interconnect layer on a tubular solid oxide fuel cell with plasma arc spray deposition. The principal objective was to determine the process variables for the plasma spray deposition of an interconnect with adequate electrical conductivity and other desired properties. Plasma arc spray deposition is a process where the coating material in powder form is heated to or above its melting temperature, while being accelerated by a carrier gas stream through a high power electric arc. The molten powder particles are directed at the substrate, and on impact, form a coating consisting of many layers of overlapping, thin, lenticular particles or splats. The variables investigated were gun power, spray distance, powder feed rate, plasma gas flow rates, number of gun passes, powder size distribution, injection angle of powder into the plasma plume, vacuum or atmospheric plasma spraying, and substrate heating. Typically, coatings produced by both systems showed bands of lanthanum rich material and cracking with the coating. Preheating the substrate reduced but did not eliminate internal coating cracking. A uniformly thick, dense, adherent interconnect of the desired chemistry was finally achieved with sufficient gas- tightness to allow fabrication of cells and samples for measurement of physical and electrical properties. A cell was tested successfully at 1000{degree}C for over 1,000 hours demonstrating the mechanical, electrical, and chemical stability of a plasma-arc sprayed interconnect layer.

  2. An arc control and protection system for the JET lower hybrid antenna based on an imaging system

    SciTech Connect (OSTI)

    Figueiredo, J.

    2014-11-15

    Arcs are the potentially most dangerous events related to Lower Hybrid (LH) antenna operation. If left uncontrolled they can produce damage and cause plasma disruption by impurity influx. To address this issue an arc real time control and protection imaging system for the Joint European Torus (JET) LH antenna has been implemented. The LH system is one of the additional heating systems at JET. It comprises 24 microwave generators (klystrons, operating at 3.7 GHz) providing up to 5 MW of heating and current drive to the JET plasma. This is done through an antenna composed of an array of waveguides facing the plasma. The protection system presented here is based primarily on an imaging arc detection and real time control system. It has adapted the ITER like wall hotspot protection system using an identical CCD camera and real time image processing unit. A filter has been installed to avoid saturation and spurious system triggers caused by ionization light. The antenna is divided in 24 Regions Of Interest (ROIs) each one corresponding to one klystron. If an arc precursor is detected in a ROI, power is reduced locally with subsequent potential damage and plasma disruption avoided. The power is subsequently reinstated if, during a defined interval of time, arcing is confirmed not to be present by image analysis. This system was successfully commissioned during the restart phase and beginning of the 2013 scientific campaign. Since its installation and commissioning, arcs and related phenomena have been prevented. In this contribution we briefly describe the camera, image processing, and real time control systems. Most importantly, we demonstrate that an LH antenna arc protection system based on CCD camera imaging systems works. Examples of both controlled and uncontrolled LH arc events and their consequences are shown.

  3. Laser-ultrasonic inspection of hybrid laser-arc welded HSLA-65 steel

    SciTech Connect (OSTI)

    Lvesque, D.; Rousseau, G.; Monchalin, J.-P. [National Research Council Canada, Boucherville, QC (Canada); Wanjara, P.; Cao, X. [National Research Council Canada, Montreal, QC (Canada)

    2014-02-18

    The hybrid laser-arc welding (HLAW) process is a relatively low heat input joining technology that combines the synergistic qualities of both the high energy density laser beam for deep penetration and the arc for wide fit-up gap tolerance. This process is especially suitable for the shipbuilding industry where thick-gauge section, long steel plates have been widely used in a butt joint configuration. In this study, preliminary exploration was carried out to detect and visualize the welding defects using laser ultrasonics combined with the synthetic aperture focusing technique (SAFT). Results obtained on 9.3 mm thick butt-welded HSLA-65 steel plates indicated that the laser-ultrasonic SAFT inspection technique can successfully detect and visualize the presence of porosity, lack of fusion and internal crack defects. This was further confirmed by X-ray digital radiography and metallography. The results obtained clearly show the potential of using the laser-ultrasonic technology for the automated inspection of hybrid laser-arc welds.

  4. Arc plasma generator of atomic driver for steady-state negative ion source

    SciTech Connect (OSTI)

    Ivanov, A. A.; Belchenko, Yu. I.; Davydenko, V. I.; Novosibirsk State University, Novosibirsk ; Ivanov, I. A.; Kolmogorov, V. V.; Listopad, A. A. Mishagin, V. V.; Shulzhenko, G. I.; Putvinsky, S. V.; Smirnov, A.

    2014-02-15

    The paper reviews the results of development of steady-state arc-discharge plasma generator with directly heated LaB{sub 6} cathode. This arc-discharge plasma generator produces a plasma jet which is to be converted into an atomic one after recombination on a metallic plate. The plate is electrically biased relative to the plasma in order to control the atom energies. Such an intensive jet of hydrogen atoms can be used in negative ion sources for effective production of negative ions on a cesiated surface of plasma grid. All elements of the plasma generator have an augmented water cooling to operate in long pulse mode or in steady state. The thermo-mechanical stresses and deformations of the most critical elements of the plasma generator were determined by simulations. Magnetic field inside the discharge chamber was optimized to reduce the local power loads. The first tests of the steady-state arc plasma generator prototype have performed in long-pulse mode.

  5. Preliminary photovoltaic arc-fault prognostic tests using sacrificial fiber optic cabling.

    SciTech Connect (OSTI)

    Johnson, Jay; Blemel, Kenneth D.; Peter, Francis

    2013-02-01

    Through the New Mexico Small Business Assistance Program, Sandia National Laboratories worked with Sentient Business Systems, Inc. to develop and test a novel photovoltaic (PV) arc-fault detection system. The system operates by pairing translucent polymeric fiber optic sensors with electrical circuitry so that any external abrasion to the system or internal heating causes the fiber optic connection to fail or detectably degrade. A periodic pulse of light is sent through the optical path using a transmitter-receiver pair. If the receiver does not detect the pulse, an alarm is sounded and the PV system can be de-energized. This technology has the unique ability to prognostically determine impending failures to the electrical system in two ways: (a) the optical connection is severed prior to physical abrasion or cutting of PV DC electrical conductors, and (b) the polymeric fiber optic cable melts via Joule heating before an arc-fault is established through corrosion. Three arc-faults were created in different configurations found in PV systems with the integrated fiber optic system to determine the feasibility of the technology. In each case, the fiber optic cable was broken and the system annunciated the fault.

  6. Statistical analysis of multipole components in the magnetic field of the RHIC arc regions

    SciTech Connect (OSTI)

    Beebe-Wang,J.; Jain, A.

    2009-05-04

    The existence of multipolar components in the dipole and quadrupole magnets is one of the factors limiting the beam stability in the RHIC operations. Therefore, the statistical properties of the non-linear fields are crucial for understanding the beam behavior and for achieving the superior performance in RHIC. In an earlier work [1], the field quality analysis of the RHIC interaction regions (IR) was presented. Furthermore, a procedure for developing non-linear IR models constructed from measured multipolar data of RHIC IR magnets was described. However, the field quality in the regions outside of the RHIC IR had not yet been addressed. In this paper, we present the statistical analysis of multipolar components in the magnetic fields of the RHIC arc regions. The emphasis is on the lower order components, especially the sextupole in the arc dipole and the 12-pole in the quadrupole magnets, since they are shown to have the strongest effects on the beam stability. Finally, the inclusion of the measured multipolar components data of RHIC arc regions and their statistical properties into tracking models is discussed.

  7. Physical characteristics of gliding arc discharge plasma generated in a laval nozzle

    SciTech Connect (OSTI)

    Lu, S. Y.; Sun, X. M.; Li, X. D.; Yan, J. H.; Du, C. M.

    2012-07-15

    The dynamic behavior of gliding arc discharge generated in a Laval nozzle has been investigated by electrical diagnostics and a high-speed camera. The results show that the voltage waveform keeps the initial shape as the gas flow rate is small, while it becomes less stable with increasing flow rate. During the first half of a cycle, the voltage rises and after that it decreases. In nitrogen and oxygen, the break down voltage for the arc is between 3.3 and 5.5 kV, while it is between 3.3-7.5 kV in air. The waveform of current I remains almost stable; and for nitrogen and oxygen, the maximum value of current I is between 0.28 and 0.46 A. With increasing flow rate, the power consumption in air first increases and then decreases; it remains in the range of 110-217 W, and gradually increases in nitrogen and oxygen. The power consumption in oxygen is lower than that in nitrogen; the input of the energy density decreases with increasing flow rate for all the three gases. The development of the arc is tracked and recorded by a high-speed camera. The cycle is stable at 10 ms for flow rates up to 1 m{sup 3} h{sup -1}. At a higher flow rate, the cycle becomes unstable.

  8. Pressure and arc voltage coupling in dc plasma torches: Identification and extraction of oscillation modes

    SciTech Connect (OSTI)

    Rat, V.; Coudert, J. F.

    2010-08-15

    This work is devoted to the instabilities occurring in a plasma torch, such as those found in plasma spraying. These instabilities are responsible for a lack of reproducibility of coatings properties, especially in the case of suspension plasma spraying that is an innovative way to obtain thin coatings of submicron-sized particles. Strong Helmholtz oscillations are highlighted in the plasma flow and it is demonstrated that they overlap with different acoustic modes in addition with the more commonly admitted ''restrike'' mode, the later being due to rearcing events in the arc region. The instabilities occur in the arc voltage but it is experimentally shown in this paper that the pressure within the torch body presents the same kind of instabilities. Besides, a numerical filtering technique has been adapted to isolate the different instability components. The operating parameters of the plasma torch were varied in order to highlight their influence on the amplitude of the different modes, both for the arc voltage and the pressure.

  9. Modeling of Interstellar Scintillation Arcs from Pulsar B1133+16

    E-Print Network [OSTI]

    Frank S. Trang; Barney J. Rickett

    2007-02-07

    The parabolic arc phenomenon visible in the Fourier analysis of the scintillation spectra of pulsars provides a new method of investigating the small scale structure in the ionized interstellar medium (ISM). We report archival observations of the pulsar B1133+16 showing both forward and reverse parabolic arcs sampled over 14 months. These features can be understood as the mutual interference between an assembly of discrete features in the scattered brightness distribution. By model-fitting to the observed arcs at one epoch we obtain a ``snap-shot'' estimate of the scattered brightness, which we show to be highly anisotropic (axial ratio >10:1), to be centered significantly off axis and to have a small number of discrete maxima, which are coarser the speckle expected from a Kolmogorov spectrum of interstellar plasma density. The results suggest the effects of highly localized discrete scattering regions which subtend 0.1-1 mas, but can scatter (or refract) the radiation by angles that are five or more times larger.

  10. Optimization of the output and efficiency of a high power cascaded arc hydrogen plasma source

    SciTech Connect (OSTI)

    Vijvers, W. A. J.; Gils, C. A. J. van; Goedheer, W. J.; Meiden, H. J. van der; Veremiyenko, V. P.; Westerhout, J.; Lopes Cardozo, N. J.; Rooij, G. J. van; Schram, D. C.

    2008-09-15

    The operation of a cascaded arc hydrogen plasma source was experimentally investigated to provide an empirical basis for the scaling of this source to higher plasma fluxes and efficiencies. The flux and efficiency were determined as a function of the input power, discharge channel diameter, and hydrogen gas flow rate. Measurements of the pressure in the arc channel show that the flow is well described by Poiseuille flow and that the effective heavy particle temperature is approximately 0.8 eV. Interpretation of the measured I-V data in terms of a one-parameter model shows that the plasma production is proportional to the input power, to the square root of the hydrogen flow rate, and is independent of the channel diameter. The observed scaling shows that the dominant power loss mechanism inside the arc channel is one that scales with the effective volume of the plasma in the discharge channel. Measurements on the plasma output with Thomson scattering confirm the linear dependence of the plasma production on the input power. Extrapolation of these results shows that (without a magnetic field) an improvement in the plasma production by a factor of 10 over where it was in van Rooij et al. [Appl. Phys. Lett. 90, 121501 (2007)] should be possible.

  11. MULTIPASS MUON RLA RETURN ARCS BASED ON LINEAR COMBINED-FUNCTION MAGNETS

    SciTech Connect (OSTI)

    Vasiliy Morozov, Alex Bogacz, Yves Roblin, Kevin Beard

    2011-09-01

    Recirculating Linear Accelerators (RLA) are an efficient way of accelerating short-lived muons to the multi-GeV energies required for Neutrino Factories and TeV energies required for Muon Colliders. In this paper we present a design of a two-pass RLA return arc based on linear combined function magnets, in which both charge muons with momenta different by a factor of two are transported through the same string of magnets. The arc is composed of 60{sup o}-bending symmetric super cells allowing for a simple arc geometry closing. By adjusting the dipole and quadrupole components of the combined-function magnets, each super cell is designed to be achromatic and to have zero initial and final periodic orbit offsets for both muon momenta. Such a design provides a greater compactness than, for instance, an FFAG lattice with its regular alternating bends and is expected to possess a large dynamic aperture characteristic of linear-field lattices.

  12. Mechanism of Synthesis of Ultra-Long Single Wall Carbon Nanotubes in Arc Discharge Plasma

    SciTech Connect (OSTI)

    Keidar, Michael

    2013-06-23

    In this project fundamental issues related to synthesis of single wall carbon nanotubes (SWNTs), which is relationship between plasma parameters and SWNT characteristics were investigated. Given that among plasma-based techniques arc discharge stands out as very advantageous in several ways (fewer defects, high flexibility, longer lifetime) this techniques warrants attention from the plasma physics and plasma technology standpoint. Both experimental and theoretical investigations of the plasma and SWNTs synthesis were conducted. Experimental efforts focused on plasma diagnostics, measurements of nanostructures parameters, and nanoparticle characterization. Theoretical efforts focused to focus on multi-dimensional modeling of the arc discharge and single wall nanotube synthesis in arc plasmas. It was demonstrated in experiment and theoretically that controlling plasma parameters can affect nanostucture synthesis altering SWNT properties (length and diameter) and leading to synthesis of new structures such as a few-layer graphene. Among clearly identified parameters affecting synthesis are magnetic and electric fields. Knowledge of the plasma parameters and discharge characteristics is crucial for ability to control synthesis process by virtue of both magnetic and electric fields. New graduate course on plasma engineering was introduced into curriculum. 3 undergraduate students were attracted to the project and 3 graduate students (two are female) were involved in the project. Undergraduate student from Historically Black University was attracted and participated in the project during Summer 2010.

  13. Effect of cerium ions in an arc peripheral plasma on the growth of radial single-walled carbon nanotubes

    SciTech Connect (OSTI)

    Sato, Y.; Motomiya, K.; Jeyadevan, B.; Tohji, K.; Sato, G.; Ishida, H.; Hirata, T.; Hatakeyama, R.

    2005-11-01

    Radial single-walled carbon nanotubes (radial SWCNTs) are formed by using a direct current (dc) arc discharge when carbon and metal atoms are mixed in a gas phase after the vaporization and cooled together in a liquid droplet. Since SWCNTs sprout through the precipitation of saturated carbon atoms from liquid droplets during cooling, a mass synthesis of radial SWCNTs can be achieved when a large number of liquid droplets are generated. In order to understand the effects of arc peripheral plasma parameters (electrons, ions, radical atoms, and molecules) on the growth of radial SWCNTs, the optimum production efficiency of radial SWCNTs is investigated by superimposing a radio-frequency (rf) plasma on the thermal arc plasma and controlling the arc peripheral plasma density. Two parameters--the rf power and the dc potential--of the rf electrode, which is equipped above 20 mm from the center of an arc-discharge point, are changed with the constant He pressure (200 Torr), dc arc current (75 A), and power (2000 W). The production yield of radial SWCNTs is found to be enhanced under the condition of the rf power of 100 W and the dc component of the rf electrode voltage of -22 V, revealing that the optimum ion flux and ion bombardment energy are important key parameters for the formation of radial SWCNTs.

  14. Laser-Arc Hybrid Welding of Thick Section Ni-base Alloys Advanced Modeling and Experiments

    SciTech Connect (OSTI)

    Debroy, Tarasankar; Palmer, Todd; Zhang, Wei

    2015-05-21

    Hybrid laser-arc welding of nickel-base alloys can increase productivity and decrease costs during construction and repair of critical components in nuclear power plants. However, laser and hybrid welding of nickel-base alloys is not well understood. This project sought to understand the physical processes during hybrid welding necessary to fabricate quality joints in Alloy 690, a Ni- Cr-Fe alloy. This document presents a summary of the data and results collected over the course of the project. The supporting documents are a collection of the research that has been or will be published in peer-reviewed journals along with a report from the partner at the national lab. Understanding the solidification behavior of Alloy 690 is important for knowing the final properties of the weldment. A study was undertaken to calculate the solidification parameters, such as temperature gradient, solidification rate, and cooling rate in Alloy 690 welds. With this information and measured cell and dendrite arm spacings, an Alloy 690 map was constructed to guide process parameter development and interpret fusion zones in later hybrid welds. This research is contained in Solidification Map of a Nickel Base Alloy. The keyhole formed under high laser intensity gives the hybrid welding technique the greater penetration depths compared to arc welding. However, keyhole behavior can form defects in the material, so knowing transient keyhole characteristics is important. With international collaborators, a study was undertaken to validate a new process monitoring tool known as inline coherent imaging (ICI), which is able to measure the keyhole depth with spatial and temporal resolutions on the order of 10 microns and 10 microseconds. ICI was validated for five alloy systems, including Alloy 690. Additionally, the keyhole growth rates at the start of welding were measured with unprecedented accuracy. This research is contained in Real Time Monitoring of Laser Beam Welding Keyhole Depth by Laser Interferometry. During full penetration welding of thick sections, root defects can form, which result in unacceptable weld quality. A study was undertaken to determine the competing forces in root defect formation by independently changing the weight forces and surface tension forces. The weight force was altered by changing the plate thickness, and the surface tension force was altered by changing the surface condition at the bottom surface. Root defects do depend on these two forces. This research is contained in Mitigation of Root Defect in Laser and Hybrid Laser-Arc Welding. Validation of the hybrid laser-arc model is necessary to properly model heat and mass transfer and fluid flow in Alloy 690 hybrid welds. Therefore, the developed model was validated for low carbon steel. Temperatures calculated by the model were included into a microstructural model in order to calculate the phase fractions. Process maps were developed for the selection of welding parameters to avoid martensite formation. This research is contained in Fusion Zone Microstructure in Full Penetration Laser-Arc Hybrid Welding of Low Alloy Steel. Alloy 690 suffers from ductility dip cracking, a form of hot cracking. This type of cracking inhibits the use of multipass welding to join Alloy 690. Our partners at ORNL performed some hot ductility testing with Alloy 690 samples using digital image correlation. The results of this work is contained in the report Summary of 690 ductility dip cracking testing using Gleeble and digital image correlation. Macro-porosity is a limiting factor in the widespread deployment of laser and hybrid laser-arc welding for construction and repair of nuclear power plant components. Keyhole instability and fluctuation results in the formation of large bubbles, which become trapped at the advancing solid- liquid interface as pores. Laser and hybrid laser-arc welds were fabricated for a range of conditions. Porosity levels in the welds were measured in X-ray computed tomography (CT), which provides very detailed data on the size and lo

  15. Characterization of Ion Species Mix of the Textor Diagnostic Hydrogen Beam Injector with an RF and Arc-discharge Plasma Box

    E-Print Network [OSTI]

    Ivanov, A A; Kreter, A; Maximov, V V; Podmonogin, A A; Schweer, B; Shikhoutsev, I V; Stupishin, N V; Uhlemann, R; Usoltsev, D V

    2002-01-01

    Characterization of Ion Species Mix of the Textor Diagnostic Hydrogen Beam Injector with an RF and Arc-discharge Plasma Box

  16. SU-E-T-539: Fixed Versus Variable Optimization Points in Combined-Mode Modulated Arc Therapy Planning

    SciTech Connect (OSTI)

    Kainz, K; Prah, D; Ahunbay, E; Li, X

    2014-06-01

    Purpose: A novel modulated arc therapy technique, mARC, enables superposition of step-and-shoot IMRT segments upon a subset of the optimization points (OPs) of a continuous-arc delivery. We compare two approaches to mARC planning: one with the number of OPs fixed throughout optimization, and another where the planning system determines the number of OPs in the final plan, subject to an upper limit defined at the outset. Methods: Fixed-OP mARC planning was performed for representative cases using Panther v. 5.01 (Prowess, Inc.), while variable-OP mARC planning used Monaco v. 5.00 (Elekta, Inc.). All Monaco planning used an upper limit of 91 OPs; those OPs with minimal MU were removed during optimization. Plans were delivered, and delivery times recorded, on a Siemens Artiste accelerator using a flat 6MV beam with 300 MU/min rate. Dose distributions measured using ArcCheck (Sun Nuclear Corporation, Inc.) were compared with the plan calculation; the two were deemed consistent if they agreed to within 3.5% in absolute dose and 3.5 mm in distance-to-agreement among > 95% of the diodes within the direct beam. Results: Example cases included a prostate and a head-and-neck planned with a single arc and fraction doses of 1.8 and 2.0 Gy, respectively. Aside from slightly more uniform target dose for the variable-OP plans, the DVHs for the two techniques were similar. For the fixed-OP technique, the number of OPs was 38 and 39, and the delivery time was 228 and 259 seconds, respectively, for the prostate and head-and-neck cases. For the final variable-OP plans, there were 91 and 85 OPs, and the delivery time was 296 and 440 seconds, correspondingly longer than for fixed-OP. Conclusion: For mARC, both the fixed-OP and variable-OP approaches produced comparable-quality plans whose delivery was successfully verified. To keep delivery time per fraction short, a fixed-OP planning approach is preferred.

  17. SciThur AM: YIS - 04: Gold Nanoparticle Enhanced Arc Radiotherapy: A Monte Carlo Feasibility Study

    SciTech Connect (OSTI)

    Koger, B; Kirkby, C

    2014-08-15

    Introduction: The use of gold nanoparticles (GNPs) in radiotherapy has shown promise for therapeutic enhancement. In this study, we explore the feasibility of enhancing radiotherapy with GNPs in an arc-therapy context. We use Monte Carlo simulations to quantify the macroscopic dose-enhancement ratio (DER) and tumour to normal tissue ratio (TNTR) as functions of photon energy over various tumour and body geometries. Methods: GNP-enhanced arc radiotherapy (GEART) was simulated using the PENELOPE Monte Carlo code and penEasy main program. We simulated 360 arc-therapy with monoenergetic photon energies 50 1000 keV and several clinical spectra used to treat a spherical tumour containing uniformly distributed GNPs in a cylindrical tissue phantom. Various geometries were used to simulate different tumour sizes and depths. Voxel dose was used to calculate DERs and TNTRs. Inhomogeneity effects were examined through skull dose in brain tumour treatment simulations. Results: Below 100 keV, DERs greater than 2.0 were observed. Compared to 6 MV, tumour dose at low energies was more conformai, with lower normal tissue dose and higher TNTRs. Both the DER and TNTR increased with increasing cylinder radius and decreasing tumour radius. The inclusion of bone showed excellent tumour conformality at low energies, though with an increase in skull dose (40% of tumour dose with 100 keV compared to 25% with 6 MV). Conclusions: Even in the presence of inhomogeneities, our results show promise for the treatment of deep-seated tumours with low-energy GEART, with greater tumour dose conformality and lower normal tissue dose than 6 MV.

  18. Formation of NOx precursors during Chinese pulverized coal pyrolysis in an arc plasma jet

    SciTech Connect (OSTI)

    Wei-ren Bao; Jin-cao Zhang; Fan Li; Li-ping Chang

    2007-08-15

    The formation of NOx precursors (HCN and NH{sub 3}) from the pyrolysis of several Chinese pulverized coals in an arc plasma jet was investigated through both thermodynamic analysis of the C-H-O-N system and experiments. Results of thermodynamic analysis show that the dominant N-containing gaseous species is HCN together with a small amount of ammonia above the temperature of 2000 K. The increase of H content advances the formation of HCN and NH{sub 3}, but the yields of HCN and NH{sub 3} are decreased with a high concentration of O in the system. These results are accordant with the experimental data. The increasing of input power promotes the formation of HCN and NH{sub 3} from coal pyrolysis in an arc plasma jet. Tar-N is not formed during the process. The yield of HCN changes insignificantly with the changing of the residence time of coal particles in the reactor, but that of NH{sub 3} decreases as residence times increase because of the relative instability at high temperature. Adsorption and gasification of CO{sub 2} on the coal surface also can restrain the formation of HCN and NH{sub 3} compare to the results in an Ar plasma jet. Yields of HCN and NH{sub 3} are sensitive to the coal feeding rate, indicating that NOx precursors could interact with the nascent char to form other N-containing species. The formation of HCN and NH{sub 3} during coal pyrolysis in a H{sub 2}/Ar plasma jet are not dependent on coal rank. The N-containing gaseous species is released faster than others in the volatiles during coal pyrolysis in an arc plasma jet, and the final nitrogen content in the char is lower than that in the parent coal, which it is independent of coal type. 16 refs., 9 figs., 1 tab.

  19. Boron Ion Implantation into Silicon by Use of the Boron Vacuum-Arc Plasma Generator

    SciTech Connect (OSTI)

    Williams, J. M.; Klepper, C. C.; Chivers, D. J.; Hazelton, R. C.; Moschella, J. J.; Keitz, M. D.

    2006-11-13

    This paper continues with presentation of experimental work pertaining to use of the boron vacuum arc (a.k.a. cathodic arc) plasma generator for boron doping in semiconductor silicon, particularly with a view to the problems associated with shallow junction doping. Progress includes development of an excellent and novel macroparticle filter and subsequent ion implantations. An important perceived issue for vacuum arc generators is the production of copious macroparticles from cathode material. This issue is more important for cathodes of materials such as carbon or boron, for which the particles are not molten or plastic, but instead are elastic, and tend to recoil from baffles used in particle filters. The present design starts with two vanes of special orientation, so as to back reflect the particles, while steering the plasma between the vanes by use of high countercurrents in the vanes. Secondly, behind and surrounding the vanes is a complex system of baffles that has been designed by a computer-based strategy to ultimately trap the particles for multiple bounces. The statistical transmittance of particles is less than 5 per coulomb of boron ions transmitted at a position just a few centimeters outside the filter. This value appears adequate for the silicon wafer application, but improvement is easily visualized as wafers will be situated much further away when they are treated in systems. A total of 11 silicon samples, comprising an area of 250 cm2, have been implanted. Particles were not detected. Sample biases ranged from 60 to 500 V. Boron doses ranged from 5 x 1014 to 5 x 1015/cm2. Exposure times ranged from 20 to 200 ms for average transmitted boron current values of about 125 mA. SIMS concentration profiles from crystalline material are presented. The results appear broadly favorable in relation to competitive techniques and will be discussed. It is concluded that doubly charged boron ions are not present in the plume.

  20. SpArcFiRe: Scalable automated detection of spiral galaxy arm segments

    SciTech Connect (OSTI)

    Davis, Darren R.; Hayes, Wayne B., E-mail: drdavis@uci.edu, E-mail: whayes@uci.edu [University of California, Irvine, CA 92697-3435 (United States)

    2014-08-01

    Given an approximately centered image of a spiral galaxy, we describe an entirely automated method that finds, centers, and sizes the galaxy (possibly masking nearby stars and other objects if necessary in order to isolate the galaxy itself) and then automatically extracts structural information about the spiral arms. For each arm segment found, we list the pixels in that segment, allowing image analysis on a per-arm-segment basis. We also perform a least-squares fit of a logarithmic spiral arc to the pixels in that segment, giving per-arc parameters, such as the pitch angle, arm segment length, location, etc. The algorithm takes about one minute per galaxies, and can easily be scaled using parallelism. We have run it on all ?644,000 Sloan objects that are larger than 40 pixels across and classified as 'galaxies'. We find a very good correlation between our quantitative description of a spiral structure and the qualitative description provided by Galaxy Zoo humans. Our objective, quantitative measures of structure demonstrate the difficulty in defining exactly what constitutes a spiral 'arm', leading us to prefer the term 'arm segment'. We find that pitch angle often varies significantly segment-to-segment in a single spiral galaxy, making it difficult to define the pitch angle for a single galaxy. We demonstrate how our new database of arm segments can be queried to find galaxies satisfying specific quantitative visual criteria. For example, even though our code does not explicitly find rings, a good surrogate is to look for galaxies having one long, low-pitch-angle armwhich is how our code views ring galaxies. SpArcFiRe is available at http://sparcfire.ics.uci.edu.