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Note: This page contains sample records for the topic "axial magma chamber" from the National Library of EnergyBeta (NLEBeta).
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1

{sup 226}Ra and {sup 231}Pa systematics of axial MORB, crustal residence ages, and magma chamber characteristics at 9--10{degree}N East Pacific Rise  

SciTech Connect (OSTI)

Mass spectrometric measurements of {sup 30}Th-22{sup 226}Ra and {sup 235}-U{sup 231}Pa disequilibria for axial basalts are used to determine crustal residence ages for MORB magma and investigate the temporal and spatial characteristics of axial magma chambers (AMC) at 9--10{degrees}N East Pacific Rise (EPR). Relative crustal residence ages can be calculated from variations in {sup 226}Ra/{sup 230}Th and {sup 231}Pa/{sup 235}U activity ratios for axial lavas, if (1) mantle sources and melting are uniform, and mantle transfer times are constant or rapid for axial N-MORB, and (2) {sup 231}Pa/{sup 235}U and {sup 226}Ra/{sup 230}Th in the melt are unaffected by shallow level fractional crystallization. Uniform Th, Sr, and Nd isotopic systematics and incompatible element ratios for N-MORB along the 9--10{degrees}N segment indicate that mantle sources and transfer times are similar. In addition, estimated bulk solid/melt partition coefficients for U, Th, and Pa are small, hence effects of fractional crystallization on {sup 231}Pa/{sup 235}U ratios for the melt are expected to be negligible. However, fractional crystallization of plagioclase in the AMC would lower {sup 226}Ra/{sup 230}Th ratios in the melt and produce a positive bias in {sup 226}Ra crustal residence ages for fractionated lavas.

Goldstein, S.J.; Murrell, M.T. [Los Alamos National Lab., NM (United States); Perfit, M.R. [Univ., of Florida, Gainesville, FL (United States). Dept. of Geology; Batiza, R. [Univ., of Hawaii, Honolulu, HI (United States); Fornari, D.J. [Woods Hole Oceanographic Institution, MA (United States). Dept. of Geology and Geophysics

1994-06-01T23:59:59.000Z

2

On the intermittency and crystallization mechanisms of sub-seafloor magma chambers  

Science Journals Connector (OSTI)

......that the overall pressure in the magma storage zone is not sufficient to upwell into...magma in the chamber, and the convecting seawater in the permeable surface rocks. Thicknesses...to a hydrothermal boundary at or near seawater temperature (O'C), the layer of 'plated......

C. R. B. Lister

1983-05-01T23:59:59.000Z

3

Three-dimensional temperature field simulation of magma chamber in the Los Humeros geothermal field, Puebla, Mexico  

Science Journals Connector (OSTI)

Three-dimensional (3-D) thermal modeling of a magma chamber in the Los Humeros geothermal field of Mexico was carried out for the entire geological history of about 500,000 y. Earlier application of 3-D modeling for only about 30,000 y of total simulation time with discretization time of 1000 y and mesh size of 0.25 km, had indicated that the thermal regime is affected more by the depth of magma chamber than its volume. Now using a chamber depth of 5 km, chamber volume of 1400 km3, shorter discretization time of 10 years, mesh size of 0.25 km, convection in the geothermal reservoir, and magma recharge in the chamber, we present our best 3-D thermal model for the Los Humeros geothermal field. Although this model is consistent with the static formation temperature estimates from geothermal wells, ways to improve this model to make it suitable for the estimation of geothermal budget are also pointed out.

Surendra P. Verma; Efraín Gómez-Arias

2013-01-01T23:59:59.000Z

4

Volcanic inflation measured in the caldera of Axial Seamount: Implications for magma supply and future  

E-Print Network [OSTI]

.W.Chadwick@noaa.gov) [1] Since 2000, ambient seawater pressure has been precisely measured at five seafloor benchmarks vehicle to deploy a mobile pressure recorder (MPR) in campaign-style surveys. Additionally, seawater with magma storage in a shallow reservoir underlying the caldera at a depth of $3.5 km, and the current

Nooner, Scott

5

Chemical Evolution and Chemical State of the Long Valley Magma...  

Open Energy Info (EERE)

Magma Chamber Jump to: navigation, search OpenEI Reference LibraryAdd to library Report: Chemical Evolution and Chemical State of the Long Valley Magma Chamber Abstract...

6

Seismic Evidence For A Hydrothermal Layer Above The Solid Roof Of The Axial  

Open Energy Info (EERE)

Evidence For A Hydrothermal Layer Above The Solid Roof Of The Axial Evidence For A Hydrothermal Layer Above The Solid Roof Of The Axial Magma Chamber At The Southern East Pacific Rise Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Seismic Evidence For A Hydrothermal Layer Above The Solid Roof Of The Axial Magma Chamber At The Southern East Pacific Rise Details Activities (1) Areas (1) Regions (0) Abstract: A full-waveform inversion of two-ship, wide-aperture, seismic reflection data from a ridge-crest seismic line at the southern East Pacific Rise indicates that the axial magma chamber here is about 50 m thick, is embedded within a solid roof, and has a solid floor. The 50-60-m-thick roof is overlain by a 150-200-m-thick low-velocity zone that may correspond to a fracture zone that hosts the hydrothermal circulation,

7

Investigation of MAGMA chambers in the Western Great Basin. Final report, 9 June 1982-31 October 1985  

SciTech Connect (OSTI)

This report summarizes efforts made by the Seismological Laboratory toward the detection and delineation of shallow crustal zones in the western Great Basin, and toward the development of methods to accomplish such detection. The work centers around the recently-active volcanic center near Long Valley, California. The work effort is broken down into three tasks: (1) network operations, (2) data analysis and interpretation, and (3) the study of shallow crustal amomalies (magma bodies). Section (1) describes the efforts made to record thousand of earthquakes near the Long Valley caldera, and focusses on the results obtained for the November 1984 round Valley earthquake. Section (2) describes the major effort of this contract, which was to quantify the large volume of seismic data being recorded as it pertains to the goals of this contract. Efforts described herein include (1) analysis of earthquake focal mechanisms, and (2) the classification, categorization, and interpretation of unusual seismic phases in terms of reflections and refractions from shallow-crustal anomalous zones. Section (3) summarizes the status of our research to date on the locations of magma bodies, with particular emphasis on a location corresponding to the map location of the south end of Hilton Creek fault. Five lines of independent evidence suggest that magma might be associated with this spot. Finally, new evidence on the large magma bodies within the Long Valley caldera, of interest to the DOE deep drilling project, is presented.

Peppin, W.A.

1986-02-10T23:59:59.000Z

8

O tephra from a compositionally zoned magma body: Fisher Caldera, Unimak Island, Aleutians  

E-Print Network [OSTI]

of country rocks around the magma chamber. For comparison, the d18 O of Pleistocene ice in Camp Century

Bindeman, Ilya N.

9

Oxygen isotope study of the Long Valley magma system, California: isotope thermometry and convection in large silicic magma bodies  

Science Journals Connector (OSTI)

Products of voluminous pyroclastic eruptions with eruptive draw-down of several kilometers provide a snap-shot view of batholith-scale magma chambers, and quench pre-eruptive isotopic fractionations (i.e., temper...

Ilya N. Bindeman; John W. Valley

2002-11-01T23:59:59.000Z

10

Magma chamber processes at Mutnovsky Volcano, Russia.  

E-Print Network [OSTI]

??This dissertation is composed of two manuscripts about the evolution of Mutnovsky Volcano in Kamchatka, Russia. Mutnovsky has been active for the past approximately 80,000… (more)

Robertson, Kelly L.

2011-01-01T23:59:59.000Z

11

Flow chamber  

DOE Patents [OSTI]

A flow chamber having a vacuum chamber and a specimen chamber. The specimen chamber may have an opening through which a fluid may be introduced and an opening through which the fluid may exit. The vacuum chamber may have an opening through which contents of the vacuum chamber may be evacuated. A portion of the flow chamber may be flexible, and a vacuum may be used to hold the components of the flow chamber together.

Morozov, Victor (Manassas, VA)

2011-01-18T23:59:59.000Z

12

Co-axial, high energy gamma generator  

DOE Patents [OSTI]

A gamma ray generator includes an ion source in a first chamber. A second chamber is configured co-axially around the first chamber at a lower second pressure. Co-axially arranged plasma apertures separate the two chambers and provide for restricted passage of ions and gas from the first to the second chamber. The second chamber is formed by a puller electrode having at least one long channel aperture to draw ions from the first chamber when the puller electrode is subject to an appropriate applied potential. A plurality of electrodes rings in the third chamber in third pressure co-axially surround the puller electrode and have at least one channel corresponding to the at least one puller electrode aperture and plasma aperture. The electrode rings increase the energy of the ions to a selected energy in stages in passing between successive pairs of the electrodes by application of an accelerating voltage to the successive pairs of accelerator electrodes. A target disposed co-axially around the plurality of electrodes receives the beam of accelerated ions, producing gamma rays.

Reijonen, Jani Petteri (Princeton, NJ); Gicquel, Frederic (Pennington, NJ)

2011-08-16T23:59:59.000Z

13

Role of oxidized, S-rich mafic magmas for giant Cu mineralization: Evidence from Pinatubo, Bingham Canyon and El Teniente  

E-Print Network [OSTI]

dacitic magma chamber (~ 800/C), then acid-sulphatehydrothermal fluids. At Bingham Canyon, UtahRole of oxidized, S-rich mafic magmas for giant Cu mineralization: Evidence from Pinatubo, Bingham Canyon and El Teniente Hattori, K.H. and De Hoog, J.C.M., Earth Sciences, Univ. Ottawa, Ottawa, K1N 6N5

14

Cyclone reactor with internal separation and axial recirculation  

DOE Patents [OSTI]

A cyclone combustor apparatus contains a circular partition plate containing a central circular aperture. The partition plate divides the apparatus into a cylindrical precombustor chamber and a combustor chamber. A coal-water slurry is passed axially into the inlet end of the precombustor chamber, and primary air is passed tangentially into said chamber to establish a cyclonic air flow. Combustion products pass through the partition plate aperture and into the combustor chamber. Secondary air may also be passed tangentially into the combustor chamber adjacent the partition plate to maintain the cyclonic flow. Flue gas is passed axially out of the combustor chamber at the outlet end and ash is withdrawn tangentially from the combuston chamber at the outlet end. A first mixture of flue gas and ash may be tangentially withdrawn from the combustor chamber at the outlet end and recirculated to the axial inlet of the precombustor chamber with the coal-water slurry. A second mixture of flue gas and ash may be tangentially withdrawn from the outlet end of the combustor chamber and passed to a heat exchanger for cooling. Cooled second mixture is then recirculated to the axial inlet of the precombustor chamber. In another embodiment a single cyclone combustor chamber is provided with both the recirculation streams of the first mixture and the second mixture.

Becker, Frederick E. (Reading, MA); Smolensky, Leo A. (Concord, MA)

1989-01-01T23:59:59.000Z

15

Magma Energy | Open Energy Information  

Open Energy Info (EERE)

Magma Energy Magma Energy Name Magma Energy Address 5500 Soda Lake Road Place Fallon, NV Zip 89406 Sector Geothermal energy Phone number 775.867.5093 Website http://www.alterrapower.ca References Alterra Power Corp[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! Magma Energy is a subsidiary of Alterra Power based in Fallon, Nevada. Alterra Power Corp. is a leading global renewable energy company. Alterra operates six power plants totaling 566 MW of capacity, including two geothermal facilities in Iceland, a geothermal plant in Nevada, British Columbia's largest run of river hydro facilities and the province's largest wind farm. Their 297 MW share of production capacity generates approximately 1,400 GWh of clean power annually. Alterra has an extensive

16

Ionization chamber  

DOE Patents [OSTI]

An ionization chamber has separate drift and detection regions electrically isolated from each other by a fine wire grid. A relatively weak electric field can be maintained in the drift region when the grid and another electrode in the chamber are connected to a high voltage source. A much stronger electric field can be provided in the detection region by connecting wire electrodes therein to another high voltage source. The detection region can thus be operated in a proportional mode when a suitable gas is contained in the chamber. High resolution output pulse waveforms are provided across a resistor connected to the detection region anode, after ionizing radiation enters the drift region and ionize the gas.

Walenta, Albert H. (Port Jefferson Station, NY)

1981-01-01T23:59:59.000Z

17

Chamber transport  

SciTech Connect (OSTI)

Heavy ion beam transport through the containment chamber plays a crucial role in all heavy ion fusion (HIF) scenarios. Here, several parameters are used to characterize the operating space for HIF beams; transport modes are assessed in relation to evolving target/accelerator requirements; results of recent relevant experiments and simulations of HIF transport are summarized; and relevant instabilities are reviewed. All transport options still exist, including (1) vacuum ballistic transport, (2) neutralized ballistic transport, and (3) channel-like transport. Presently, the European HIF program favors vacuum ballistic transport, while the US HIF program favors neutralized ballistic transport with channel-like transport as an alternate approach. Further transport research is needed to clearly guide selection of the most attractive, integrated HIF system.

OLSON,CRAIG L.

2000-05-17T23:59:59.000Z

18

Magma Energy Research Project, FY80 annual progress report  

SciTech Connect (OSTI)

The technical feasibility of extracting energy from magma bodies is explored. Five aspects of the project are studied: resource location and definition, source tapping, magma characterization, magma/material compatibility, and energy extraction.

Colp, J.L. (ed.)

1982-04-01T23:59:59.000Z

19

The Magma Energy Program | Open Energy Information  

Open Energy Info (EERE)

Journal Article: The Magma Energy Program Abstract Abstract unavailable. Authors T.Y. Chu, J.C. Dunn, John T. Finger, John B. Rundle and H.R. Westrich Published Journal Geothermal...

20

Measuring axial pump thrust  

DOE Patents [OSTI]

An apparatus for measuring the hydraulic axial thrust of a pump under operation conditions is disclosed. The axial thrust is determined by forcing the rotating impeller off of an associated thrust bearing by use of an elongate rod extending coaxially with the pump shaft. The elongate rod contacts an impeller retainer bolt where a bearing is provided. Suitable measuring devices measure when the rod moves to force the impeller off of the associated thrust bearing and the axial force exerted on the rod at that time. The elongate rod is preferably provided in a housing with a heat dissipation mechanism whereby the hot fluid does not affect the measuring devices. 1 fig.

Suchoza, B.P.; Becse, I.

1988-11-08T23:59:59.000Z

Note: This page contains sample records for the topic "axial magma chamber" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Axial static mixer  

DOE Patents [OSTI]

Static axial mixing apparatus includes a plurality of channels, forming flow paths of different dimensions. The axial mixer includes a flow adjusting device for adjustable selective control of flow resistance of various flow paths in order to provide substantially identical flows through the various channels, thereby reducing nonuniform coating of interior surfaces of the channels. The flow adjusting device may include diaphragm valves, and may further include a pressure regulating system therefor.

Sandrock, H.E.

1982-05-06T23:59:59.000Z

22

Causes and consequences of unsteady crustal magma transport  

E-Print Network [OSTI]

The theory of subcritical crack growth with application toJin. Magma-driven subcritical crack growth and implications

Karlstrom, Leif

2011-01-01T23:59:59.000Z

23

THERMODYNAMIC AND TRANSPORT PROPERTIES OF SILICATE MELTS AND MAGMA  

E-Print Network [OSTI]

PROPERTIES5 Density and Equation of State6 Enthalpy, Entropy and Heat Capacity7 VI. MAGMA TRANSPORT-1- THERMODYNAMIC AND TRANSPORT PROPERTIES OF SILICATE MELTS AND MAGMA Charles E. Lesher PROPERTIES8 Magma Rheology9 Thermal Conductivity: Radiative and Phonon10 Diffusion: Self, Tracer and Chemical

Spera, Frank J.

24

Validation of the neutron and gamma fields in the JSI TRIGA reactor using in-core fission and ionization chambers  

Science Journals Connector (OSTI)

Abstract CEA developed fission chambers and ionization chambers were utilized at the JSI TRIGA reactor to measure neutron and gamma fields. The measured axial fission rate distributions in the reactor core are generally in good agreement with the calculated values using the Monte Carlo model of the reactor thus verifying both the computational model and the fission chambers. In future, multiple absolutely calibrated fission chambers could be used for more accurate online reactor thermal power monitoring.

Gašper Žerovnik; Tanja Kaiba; Vladimir Radulovi?; Anže Jazbec; Sebastjan Rupnik; Loďc Barbot; Damien Fourmentel; Luka Snoj

2015-01-01T23:59:59.000Z

25

Global Magma Energy Group | Open Energy Information  

Open Energy Info (EERE)

Global Magma Energy Group Global Magma Energy Group Place Houston, Texas Zip 77056 Sector Geothermal energy Product A geothermal development firm focussed on Asia and backed by Arctas Capital and John Wheble & Associates. Coordinates 29.76045°, -95.369784° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":29.76045,"lon":-95.369784,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

26

Thermal techniques for characterizing magma body geometries | Open Energy  

Open Energy Info (EERE)

techniques for characterizing magma body geometries techniques for characterizing magma body geometries Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Thermal techniques for characterizing magma body geometries Details Activities (1) Areas (1) Regions (0) Abstract: The surface heat flux distribution resulting from emplaced magma bodies can be used to help characterize the magma source. Closed-form analytical solutions for the conduction heat transfer from various idealized magma geometries (dikes, sills, and spheres) are obtained using either the Schwarz-Christoffel transformation theorem (dikes and sills) or the 'method of images' with superposition (spheres). Comparison of these analytically determined heat flux distributions with field data from active geothermal areas at Yellowstone, Avachinsky volcano, Kilauea Iki,

27

The Environmental Chamber  

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

2 2 The Environmental Chamber Al Hodgson and Richard Allen test methyl chloride exposures using the environmental chamber. On the second floor of an unremarkable building at LBL, researchers are using a room within a room to smoke out indoor air pollutants. The environmental chamber is a stainless-steel-lined room of 540 ft cubed (20 meters cubed) which can be operated in several ways to meet the needs of different research projects, including studies for which a very low background is required. Scientists of the Indoor Environment Program and their collaborators use the chamber as a controlled indoor environment to study the behavior of a variety of indoor pollutants ranging from cigarette smoke to volatile organic compounds (VOCs) from new carpets. At the moment, four projects use the facility. Principal investigator Al

28

BNL | ATF Experimental Chambers  

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

Laser Injection Vacuum Chamber Located on beam line 1, the "Smith-Purcell box" has 140 liters of usable volume. Due to its size, it is mounted on a fixed platform. Hosted...

29

PLASMA GPU MAGMA Rendimiento Trabajo Futuro Matrix Algebra on GPU and Multicore Architecture  

E-Print Network [OSTI]

PLASMA GPU MAGMA Rendimiento Trabajo Futuro MAGMA Matrix Algebra on GPU and Multicore Architecture diciembre de 2010 1 / 26 #12;PLASMA GPU MAGMA Rendimiento Trabajo Futuro ĂŤndice 1 PLASMA ÂżQue es PLASMA Trabajo Futuro PLASMA MAGMA 2 / 26 #12;PLASMA GPU MAGMA Rendimiento Trabajo Futuro ÂżQue es PLASMA

Giménez, Domingo

30

Mercury Chamber Considerations  

E-Print Network [OSTI]

Mercury Chamber Considerations V. Graves IDS-NF Target Studies July 2011 #12;2 Managed by UT-Battelle for the U.S. Department of Energy Mercury Chamber Considerations, July 2011 Flow Loop Review · 1 cm dia nozzle, 20 m/s jet requires 1.57 liter/sec mercury flow (94.2 liter/min, 24.9 gpm). · MERIT experiment

McDonald, Kirk

31

Sleeve reaction chamber system  

DOE Patents [OSTI]

A chemical reaction chamber system that combines devices such as doped polysilicon for heating, bulk silicon for convective cooling, and thermoelectric (TE) coolers to augment the heating and cooling rates of the reaction chamber or chambers. In addition the system includes non-silicon-based reaction chambers such as any high thermal conductivity material used in combination with a thermoelectric cooling mechanism (i.e., Peltier device). The heat contained in the thermally conductive part of the system can be used/reused to heat the device, thereby conserving energy and expediting the heating/cooling rates. The system combines a micromachined silicon reaction chamber, for example, with an additional module/device for augmented heating/cooling using the Peltier effect. This additional module is particularly useful in extreme environments (very hot or extremely cold) where augmented heating/cooling would be useful to speed up the thermal cycling rates. The chemical reaction chamber system has various applications for synthesis or processing of organic, inorganic, or biochemical reactions, including the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction.

Northrup, M. Allen (Berkeley, CA); Beeman, Barton V. (San Mateo, CA); Benett, William J. (Livermore, CA); Hadley, Dean R. (Manteca, CA); Landre, Phoebe (Livermore, CA); Lehew, Stacy L. (Livermore, CA); Krulevitch, Peter A. (Pleasanton, CA)

2009-08-25T23:59:59.000Z

32

The Magma Energy Exploratory Well | Open Energy Information  

Open Energy Info (EERE)

Article: The Magma Energy Exploratory Well Abstract Abstract unavailable. Authors John T. Finger and John C. Eichelberger Published Journal Geothermal Resources Council...

33

Development of the Long Valley, California, magma chamber recorded in precaldera rhyolite lavas of Glass Mountain  

Science Journals Connector (OSTI)

Glass Mountain, California, consists of >50 km3...of high-silica rhyolite lavas and associated pyroclastic deposits that erupted over a period of >1 my preceding explosive eruption of the Bishop Tuff and formatio...

J. M. Metz; G. A. Mahood

34

Liquid Wall Chambers  

SciTech Connect (OSTI)

The key feature of liquid wall chambers is the use of a renewable liquid layer to protect chamber structures from target emissions. Two primary options have been proposed and studied: wetted wall chambers and thick liquid wall (TLW) chambers. With wetted wall designs, a thin layer of liquid shields the structural first wall from short ranged target emissions (x-rays, ions and debris) but not neutrons. Various schemes have been proposed to establish and renew the liquid layer between shots including flow-guiding porous fabrics (e.g., Osiris, HIBALL), porous rigid structures (Prometheus) and thin film flows (KOYO). The thin liquid layer can be the tritium breeding material (e.g., flibe, PbLi, or Li) or another liquid metal such as Pb. TLWs use liquid jets injected by stationary or oscillating nozzles to form a neutronically thick layer (typically with an effective thickness of {approx}50 cm) of liquid between the target and first structural wall. In addition to absorbing short ranged emissions, the thick liquid layer degrades the neutron flux and energy reaching the first wall, typically by {approx}10 x x, so that steel walls can survive for the life of the plant ({approx}30-60 yrs). The thick liquid serves as the primary coolant and tritium breeding material (most recent designs use flibe, but the earliest concepts used Li). In essence, the TLW places the fusion blanket inside the first wall instead of behind the first wall.

Meier, W R

2011-02-24T23:59:59.000Z

35

Secondary emission gas chamber  

E-Print Network [OSTI]

For a hadron calorimeter active element there is considered a gaseous secondary emis-sion detector (150 micron gap, 50 kV/cm). Such one-stage parallel plate chamber must be a radiation hard, fast and simple. A model of such detector has been produced, tested and some characteristics are presented.

V. In'shakov; V. Kryshkin; V. Skvortsov

2014-12-10T23:59:59.000Z

36

Improved wire chamber  

DOE Patents [OSTI]

An improved gas mixture for use with proportional counter devices, such as Geiger-Mueller tubes and drift chambers. The improved gas mixture provides a stable drift velocity while eliminating wire aging caused by prior art gas mixtures. The new gas mixture is comprised of equal parts argon and ethane gas and having approximately 0.25% isopropyl alcohol vapor. 2 figs.

Atac, M.

1987-05-12T23:59:59.000Z

37

Magma energy extraction - Annual Report for FY88  

SciTech Connect (OSTI)

Thermal energy contained in magmatic systems represents a huge potential resource. In the US, useful energy contained in molten and partially-molten magma within the upper 10 km of the crust has been estimated at 50,000 to 500,000 Quads. The objective of the Magma Energy Extraction Program is to determine engineering feasibility of locating, accessing and utilizing magma as a viable energy resource. Engineering feasibility will depend on size and depth of the resource; extraction rates; and material life times. 11 refs., 29 figs., 1 tab.

Dunn, J.C. (ed.)

1989-08-01T23:59:59.000Z

38

The effect of edifice load on magma ascent beneath a volcano  

Science Journals Connector (OSTI)

...2000) The e ect of edi ce load on magma ascent beneath a volcano...May. Petrological and isotopic data also indicate magma arrest at...2000) The e ect of edi ce load on magma ascent beneath a volcano...2000) The e ect of edi ce load on magma ascent beneath a volcano...

2000-01-01T23:59:59.000Z

39

Multi-anode ionization chamber  

DOE Patents [OSTI]

The present invention includes a high-energy detector having a cathode chamber, a support member, and anode segments. The cathode chamber extends along a longitudinal axis. The support member is fixed within the cathode chamber and extends from the first end of the cathode chamber to the second end of the cathode chamber. The anode segments are supported by the support member and are spaced along the longitudinal surface of the support member. The anode segments are configured to generate at least a first electrical signal in response to electrons impinging thereon.

Bolotnikov, Aleksey E. (South Setauket, NY); Smith, Graham (Port Jefferson, NY); Mahler, George J. (Rocky Point, NY); Vanier, Peter E. (Setauket, NY)

2010-12-28T23:59:59.000Z

40

The four-chambered heart.  

E-Print Network [OSTI]

??The Four-Chambered Heart is a collection of four short stories centering around themes and motifs most popular in the genre of magical realism. Important to… (more)

Christie, Jennifer L.

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "axial magma chamber" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Petrologic constraints on the development of a large-volume, high temperature, silicic magma system: The Twin Falls eruptive centre, central Snake River Plain  

Science Journals Connector (OSTI)

Explosive volcanism associated with the Yellowstone hotspot spanning ~ 11.3 to 9 Ma, thought to have erupted from the Twin Falls eruptive centre, is recorded in the Cassia Mountains of southern Idaho and northern Nevada. The stratigraphy contains intensely welded, rhyolitic (SiO2 69–76 wt.%) ignimbrites with an anhydrous mineralogy: plagioclase, sanidine, quartz, pigeonite, augite, ilmenite, titanomagnetite, accessory zircon and apatite. Several different thermometers indicate high temperature rhyolitic magmas (> 900 °C). All Cassia Mountain ignimbrites show a significant depletion in ?18OVSMOW with magmatic feldspar values between 1.7 and 3.0‰, reflecting incorporation of a hydrothermally altered protolith. Multiple compositions of both pigeonite (Mg# 30–46) and augite (Mg# 17–53) may occur within an individual ignimbrite while crystal aggregates contain only a single composition of each. The compositional heterogeneity within the ignimbrites reflects a complex magmatic system whereby magma was segregated into multiple smaller chambers prior to eruption.

Ben S. Ellis; Tiffany Barry; Michael J. Branney; John A. Wolff; Ilya Bindeman; Rob Wilson; Bill Bonnichsen

2010-01-01T23:59:59.000Z

42

A Multidisciplinary Approach To Detect Active Pathways For Magma Migration  

Open Energy Info (EERE)

Multidisciplinary Approach To Detect Active Pathways For Magma Migration Multidisciplinary Approach To Detect Active Pathways For Magma Migration And Eruption At Mt Etna (Sicily, Italy) Before The 2001 And 2002-2003 Eruptions Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Multidisciplinary Approach To Detect Active Pathways For Magma Migration And Eruption At Mt Etna (Sicily, Italy) Before The 2001 And 2002-2003 Eruptions Details Activities (0) Areas (0) Regions (0) Abstract: Two strong flank eruptions occurred in July-August 2001 and from late October 2002 to late January 2003 at Mt. Etna volcano. The two eruptions mainly involved the upper southern flank of the volcano, a particularly active area during the last 30 years, damaging several tourist facilities and threatening some villages. The composite eruptive activity

43

LRL 25-inch Bubble Chamber  

DOE R&D Accomplishments [OSTI]

The recently completed 25-inch hydrogen bubble chamber combines excellent picture quality with a fast operating cycle. The chamber has a unique optical system and is designed to take several pictures each Bevatron pulse, in conjunction with the Bevatron rapid beam ejection system.

Alvarez, L. W.; Gow, J. D.; Barrera, F.; Eckman, G.; Shand, J.; Watt, R.; Norgren, D.; Hernandez, H. P.

1964-07-08T23:59:59.000Z

44

MFE Chamber Overview Mohamed Abdou  

E-Print Network [OSTI]

MFE Chamber Overview Mohamed Abdou Presented to: Chamber Technology Peer Review UCLA, Los Angeles/Be/structure thermomechanics interactions - Framework: IEA collaboration; part of US strategy to gain access to the larger to VNS; sparked world interest - IEA initiated a study in 1994 on VNS, called HVPNS. A scholarly

Abdou, Mohamed

45

Ion chamber based neutron detectors  

DOE Patents [OSTI]

A neutron detector with monolithically integrated readout circuitry, including: a bonded semiconductor die; an ion chamber formed in the bonded semiconductor die; a first electrode and a second electrode formed in the ion chamber; a neutron absorbing material filling the ion chamber; and the readout circuitry which is electrically coupled to the first and second electrodes. The bonded semiconductor die includes an etched semiconductor substrate bonded to an active semiconductor substrate. The readout circuitry is formed in a portion of the active semiconductor substrate. The ion chamber has a substantially planar first surface on which the first electrode is formed and a substantially planar second surface, parallel to the first surface, on which the second electrode is formed. The distance between the first electrode and the second electrode may be equal to or less than the 50% attenuation length for neutrons in the neutron absorbing material filling the ion chamber.

Derzon, Mark S; Galambos, Paul C; Renzi, Ronald F

2014-12-16T23:59:59.000Z

46

E-Print Network 3.0 - arc magma genesis Sample Search Results  

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

of oxidized, S-rich mafic magmas for giant Cu mineralization: Evidence from Pinatubo, Bingham Canyon and El Teniente Summary: Role of oxidized, S-rich mafic magmas for giant Cu...

47

ORIGINAL PAPER Assimilation and diffusion during xenolith-magma  

E-Print Network [OSTI]

(responsible for the linear mixing trends) and (2) diffusion-controlled redistribution of elements between bothORIGINAL PAPER Assimilation and diffusion during xenolith-magma interaction: a case study the assimilation of granitic melt. Linear mixing trends on Harker diagrams for most network-forming and mainly slow-diffusing

Podladchikov, Yuri

48

Magma to Microbe: Modeling Hydrothermal Processes at Ocean Spreading Centers  

E-Print Network [OSTI]

215 Magma to Microbe: Modeling Hydrothermal Processes at Ocean Spreading Centers Geophysical is very limited. Low-temperature diffuse vent fluids, ubiquitous at hydrothermal systems, provide one microorganisms from diffuse hydrothermal vent fluids and the subseafloor at basalt-hosted mid-ocean ridges

Holden, James F.

49

Bubble growth during decompression of magma: experimental and theoretical investigation  

E-Print Network [OSTI]

Bubble growth during decompression of magma: experimental and theoretical investigation N.G. Lensky, Israel Abstract A model of bubble growth during decompression of supersaturated melt was developed in order to explore the conditions for preservation of gas overpressure in bubbles or for maintaining

Lyakhovsky, Vladimir

50

Argonne starts huilding huge bubble chamber  

Science Journals Connector (OSTI)

Argonne starts huilding huge bubble chamber ... Construction has started on the $10 million bubble chamber to be built at Argonne National Laboratory, Argonne, 111. ... Claimed by Argonne to be the world's largest chamber, it will be completed in 1969. ...

1967-06-26T23:59:59.000Z

51

Light diffusing fiber optic chamber  

DOE Patents [OSTI]

A light diffusion system for transmitting light to a target area. The light is transmitted in a direction from a proximal end to a distal end by an optical fiber. A diffusing chamber is operatively connected to the optical fiber for transmitting the light from the proximal end to the distal end and transmitting said light to said target area. A plug is operatively connected to the diffusing chamber for increasing the light that is transmitted to the target area.

Maitland, Duncan J. (Lafayette, CA)

2002-01-01T23:59:59.000Z

52

PWR AXIAL BURNUP PROFILE ANALYSIS  

SciTech Connect (OSTI)

The purpose of this activity is to develop a representative ''limiting'' axial burnup profile for pressurized water reactors (PWRs), which would encompass the isotopic axial variations caused by different assembly irradiation histories, and produce conservative isotopics with respect to criticality. The effect that the low burnup regions near the ends of spent fuel have on system reactivity is termed the ''end-effect''. This calculation will quantify the end-effects associated with Pressurized Water Reactor (PWR) fuel assemblies emplaced in a hypothetical 21 PWR waste package. The scope of this calculation covers an initial enrichment range of 3.0 through 5.0 wt% U-235 and a burnup range of 10 through 50 GWd/MTU. This activity supports the validation of the process for ensuring conservative generation of spent fuel isotopics with respect to criticality safety applications, and the use of burnup credit for commercial spent nuclear fuel. The intended use of these results will be in the development of PWR waste package loading curves, and applications involving burnup credit. Limitations of this evaluation are that the limiting profiles are only confirmed for use with the B&W 15 x 15 fuel assembly design. However, this assembly design is considered bounding of all other typical commercial PWR fuel assembly designs. This calculation is subject to the Quality Assurance Requirements and Description (QARD) because this activity supports investigations of items or barriers on the Q-list (YMP 2001).

J.M. Acaglione

2003-09-17T23:59:59.000Z

53

Directional muon jet chamber for a muon collider (Groovy Chamber)  

SciTech Connect (OSTI)

A directional jet drift chamber with PAD readout is proposed here which can select vertex originated muons within a given time window and eliminate those muons which primarily originate upstream, using only a PAD readout. Drift time provides the Z-coordinate, and the center of gravity of charge distribution provides the r-{psi} coordinates. Directionality at the trigger level is obtained by the timing measurement from the PAD hits within a given time window. Because of the long drift time between the bunch crossings, a muon collider enables one to choose a drift distance in the drift chamber as long as 50 cm. This is an important factor in reducing cost of drift chambers which have to cover relatively large areas.

Atac, M. [Fermi National Accelerator Lab., Batavia, IL (United States)]|[Univ. of California, Los Angeles, CA (United States)

1996-10-01T23:59:59.000Z

54

Axial cylinder internal combustion engine  

SciTech Connect (OSTI)

This patent describes improvement in a barrel type internal combustion engine including an engine block having axial-positioned cylinders with reciprocating pistons arranged in a circular pattern: a drive shaft concentrically positioned within the cylinder block having an offset portion extending outside the cylinder block; a wobble spider rotatably journaled to the offset portion; connecting rods for each cylinder connecting each piston to the wobble spider. The improvement comprising: a first sleeve bearing means supporting the drive shaft in the engine block in a cantilevered manner for radial loads; a second sleeve bearing means rotatably supporting the wobble spider on the offset portion of the drive shaft for radial loads; a first roller bearing means positioned between the offset portion of the drive shaft and the wobble spider carrying thrust loadings only; a second roller bearing means carrying thrust loads only reacting to the first roller bearing located on the opposite end of the driveshaft between the shaft and the engine block.

Gonzalez, C.

1992-03-10T23:59:59.000Z

55

Axial interaction free-electron laser  

DOE Patents [OSTI]

Electron orbits from a helical axial wiggler in an axial guide field are absolutely unstable as power is extracted from the particles. For off-axis beams an axial FEL mechanism exists when the axial electric field in a TM mode is wiggled to interact with the axial velocity of the electrons that form the beam. The interaction strength is comparable to that for helical FELs and is insensitive to beam orbit errors. The orbits for this mechanism are extremely stable in the absence of space charge and lead to high extraction efficiencies without particle phasing incoherence or interception. This interaction mechanism is suitable for use with intense annular electron beams for high power generation at microwave frequencies. 5 figs.

Carlsten, B.E.

1997-09-02T23:59:59.000Z

56

A University of Alabama Axial-Gap Electric Motor Developmenty  

E-Print Network [OSTI]

CAVT A University of Alabama Axial-Gap Electric Motor Developmenty Research Center OBJECTIVE ­ Develop axial gap permanent-magnet electric Axial motor ­ Develop axial gap permanent-magnet electric motor topologies with high torque and power densities MOTIVATION ­ Axial-gap ("pancake") motors have

Carver, Jeffrey C.

57

Characteristics of the upper crust and magma chambers along the spreading centers of the Lau back-arc basin  

E-Print Network [OSTI]

G. , Detrick, R.S. , Sinton, J. , 2002. Crustal thicknessJ.P. , Detrick, R.S. , Sinton, J. , 2004. Constructing the3767-3787. Detrick, R.S. , Sinton, J.M. , Ito, G. , Canales,

Dingler, Allison Maria Jacobs

2007-01-01T23:59:59.000Z

58

Chamber Clearing First Principles Modeling  

SciTech Connect (OSTI)

LIFE fusion is designed to generate 37.5 MJ of energy per shot, at 13.3 Hz, for a total average fusion power of 500 MW. The energy from each shot is partitioned among neutrons ({approx}78%), x-rays ({approx}12%), and ions ({approx}10%). First wall heating is dominated by x-rays and debris because the neutron mean free path is much longer than the wall thickness. Ion implantation in the first wall also causes damage such as blistering if not prevented. To moderate the peak-pulse heating, the LIFE fusion chamber is filled with a gas (such as xenon) to reduce the peak-pulse heat load. The debris ions and majority of the x-rays stop in the gas, which re-radiates this energy over a longer timescale (allowing time for heat conduction to cool the first wall sufficiently to avoid damage). After a shot, because of the x-ray and ion deposition, the chamber fill gas is hot and turbulent and contains debris ions. The debris needs to be removed. The ions increase the gas density, may cluster or form aerosols, and can interfere with the propagation of the laser beams to the target for the next shot. Moreover, the tritium and high-Z hohlraum debris needs to be recovered for reuse. Additionally, the cryogenic target needs to survive transport through the gas mixture to the chamber center. Hence, it will be necessary to clear the chamber of the hot contaminated gas mixture and refill it with a cool, clean gas between shots. The refilling process may create density gradients that could interfere with beam propagation, so the fluid dynamics must be studied carefully. This paper describes an analytic modeling effort to study the clearing and refilling process for the LIFE fusion chamber. The models used here are derived from first principles and balances of mass and energy, with the intent of providing a first estimate of clearing rates, clearing times, fractional removal of ions, equilibrated chamber temperatures, and equilibrated ion concentrations for the chamber. These can be used to scope the overall problem and provide input to further studies using fluid dynamics and other more sophisticated tools.

Loosmore, G

2009-06-09T23:59:59.000Z

59

Controlling Axial p-n Heterojunction Abruptness Through Catalyst...  

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

Axial p-n Heterojunction Abruptness Through Catalyst Alloying in Vapor-Liquid-Solid Grown Semiconductor Nanowires. Controlling Axial p-n Heterojunction Abruptness Through Catalyst...

60

Recent Advances in Chamber Science and Technology  

E-Print Network [OSTI]

Recent Advances in Chamber Science and Technology Mohamed Abdou April 8, 2002ISFNT-6 San Diego, USA #12;Recent Advances in Chamber Science & Technology OutlineOutline · Highlights of Major World - Experiments - Analysis & Design #12;Highlights of Major World Programs on Chamber (Blanket) Technology

Abdou, Mohamed

Note: This page contains sample records for the topic "axial magma chamber" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Mercury Chamber NF-IDS Meeting  

E-Print Network [OSTI]

-Battelle for the U.S. Department of Energy Mercury Chamber Update Oct 2011 Starting Point: Coil and Shielding Concept IDS120H #12;3 Managed by UT-Battelle for the U.S. Department of Energy Mercury Chamber Update Oct 2011 · Penetrations (ports) into chamber ­ Nozzle ­ Hg drains (overflow and maintenance) ­ Vents (in and out) ­ Beam

McDonald, Kirk

62

NIF Target Chamber Dedicated | National Nuclear Security Administratio...  

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

Dedicated NIF Target Chamber Dedicated June 11, 1999 NIF Target Chamber Dedicated Livermore, CA Secretary Richardson dedicates the National Ignition Facility target chamber at...

63

2014 PMEL Lab Review FY2009 Journal Articles  

E-Print Network [OSTI]

.L. Bryden (2009): Estimating the storage of anthropogenic carbon in the subtropical): Relationships between hydrothermal activity and axial magma chamber distribution, depthGuire, P. Raymond, and C.J. Tucker (2009): Carbon cycle observations: Gaps threaten

64

Timescales of Quartz Crystallization and the Longevity of the Bishop Giant Magma Body  

SciTech Connect (OSTI)

Supereruptions violently transfer huge amounts (100 s-1000 s km{sup 3}) of magma to the surface in a matter of days and testify to the existence of giant pools of magma at depth. The longevity of these giant magma bodies is of significant scientific and societal interest. Radiometric data on whole rocks, glasses, feldspar and zircon crystals have been used to suggest that the Bishop Tuff giant magma body, which erupted {approx}760,000 years ago and created the Long Valley caldera (California), was long-lived (>100,000 years) and evolved rather slowly. In this work, we present four lines of evidence to constrain the timescales of crystallization of the Bishop magma body: (1) quartz residence times based on diffusional relaxation of Ti profiles, (2) quartz residence times based on the kinetics of faceting of melt inclusions, (3) quartz and feldspar crystallization times derived using quartz+feldspar crystal size distributions, and (4) timescales of cooling and crystallization based on thermodynamic and heat flow modeling. All of our estimates suggest quartz crystallization on timescales of <10,000 years, more typically within 500-3,000 years before eruption. We conclude that large-volume, crystal-poor magma bodies are ephemeral features that, once established, evolve on millennial timescales. We also suggest that zircon crystals, rather than recording the timescales of crystallization of a large pool of crystal-poor magma, record the extended periods of time necessary for maturation of the crust and establishment of these giant magma bodies.

Gualda, Guilherme A.R.; Pamukcu, Ayla S.; Ghiorso, Mark S.; Anderson, Jr. , Alfred T.; Sutton, Stephen R.; Rivers, Mark L. (OFM Res.); (Vanderbilt); (UC)

2013-04-08T23:59:59.000Z

65

Painleve Analysis and Similarity Reductions for the Magma Equation  

E-Print Network [OSTI]

In this paper, we examine a generalized magma equation for rational values of two parameters, $m$ and $n$. Firstly, the similarity reductions are found using the Lie group method of infinitesimal transformations. The Painlev\\'e ODE test is then applied to the travelling wave reduction, and the pairs of $m$ and $n$ which pass the test are identified. These particular pairs are further subjected to the ODE test on their other symmetry reductions. Only two cases remain which pass the ODE test for all such symmetry reductions and these are completely integrable. The case when $m=0$, $n=-1$ is related to the Hirota-Satsuma equation and for $m=\\tfrac12$, $n=-\\tfrac12$, it is a real, generalized, pumped Maxwell-Bloch equation.

Shirley E. Harris; Peter A. Clarkson

2006-10-05T23:59:59.000Z

66

The Axially Symmetric One?Monopole  

Science Journals Connector (OSTI)

We present new classical generalized one?monopole solution of the SU(2) Yang?Mills?Higgs theory with the Higgs field in the adjoint representation. We show that this solution with ??winding number m?=?1 and ??winding number n?=?1 is an axially symmetric generalization of the ’t Hooft?Polyakov one?monopole. We construct this axially symmetric one?monopole solution by generalizing the large distance asymptotic solutions of the ’t Hooft?Polyakov one?monopole to the Jacobi elliptic functions and solving the second order equations of motion numerically when the Higgs potential is vanishing. This solution is a non?BPS solution.

Khai?Ming Wong; Rosy Teh

2009-01-01T23:59:59.000Z

67

Axial nucleon form factors from lattice QCD  

SciTech Connect (OSTI)

We present results on the nucleon axial form factors within lattice QCD using two flavors of degenerate twisted mass fermions. Volume effects are examined using simulations at two volumes of spatial length L=2.1 fm and L=2.8 fm. Cut-off effects are investigated using three different values of the lattice spacings, namely a=0.089 fm, a=0.070 fm and a=0.056 fm. The nucleon axial charge is obtained in the continuum limit and chirally extrapolated to the physical pion mass enabling comparison with experiment.

Alexandrou, C. [Department of Physics, University of Cyprus, P.O. Box 20537, 1678 Nicosia (Cyprus); Computation-based Science and Technology Research Center, Cyprus Institute, 20 Kavafi Str., Nicosia 2121 (Cyprus); Brinet, M.; Carbonell, J.; Harraud, P. A.; Papinutto, M. [Laboratoire de Physique Subatomique et Cosmologie, UJF/CNRS/IN2P3, 53 avenue des Martyrs, 38026 Grenoble (France); Constantinou, M. [Department of Physics, University of Cyprus, P.O. Box 20537, 1678 Nicosia (Cyprus); Guichon, P. [CEA-Saclay, IRFU/Service de Physique Nucleaire, 91191 Gif-sur-Yvette (France); Jansen, K. [NIC, DESY, Platanenallee 6, D-15738 Zeuthen (Germany); Korzec, T. [Department of Physics, University of Cyprus, P.O. Box 20537, 1678 Nicosia (Cyprus); Institut fuer Physik Humboldt Universitaet zu Berlin, Newtonstrasse 15, 12489 Berlin (Germany)

2011-02-15T23:59:59.000Z

68

Neutron-chamber detectors and applications  

SciTech Connect (OSTI)

Detector applications in Nuclear Safeguards and Waste Management have included measuring neutrons from fission and (alpha,n) reactions with well-moderated neutron proportional counters, often embedded in a slab of polyethylene. Other less-moderated geometries are useful for detecting both bare and moderated fission-source neutrons with good efficiency. The neutron chamber is an undermoderated detector design comprising a large, hollow, polyethylene-walled chamber containing one or more proportional counters. Neutron-chamber detectors are relatively inexpensive; can have large apertures, usually through a thin chamber wall; and offer very good detection efficiency per dollar. Neutron-chamber detectors have also been used for monitoring vehicles and for assaying large crates of transuranic waste. Our Monte Carlo calculations for a new application (monitoring low-density waste for concealed plutonium) illustrate the advantages of the hollow-chamber design for detecting moderated fission sources. 9 refs., 6 figs., 2 tabs.

Fehlau, P.E.; Atwater, H.F.; Coop, K.L.

1990-01-01T23:59:59.000Z

69

Georges Charpak, Particle Detectors, and Multiwire Chambers  

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

Georges Charpak, Particle Detectors, and Multiwire Chambers Georges Charpak, Particle Detectors, and Multiwire Chambers Resources with Additional Information · Patents Georges Charpak Courtesy of CERN Nobel laureate Georges Charpak [was] a pioneer in the art and science of particle detection ... . [He] developed a host of particle detectors used throughout experimental particle physics. In 1968, he invented and developed the first multiwire proportional chamber, for which he won the [Physics] Nobel Prize in 1992 ... . The multiwire chamber differed from earlier detectors in the speed with which it could record particle tracks from a collision-millions per second, rather than one or two per second for bubble chambers. The speed of the multiwire chamber and its successor technologies, along with their extraordinary precision, led to a revolution in particle physics ... . The technology that Charpak pioneered also finds applications in medicine and industry.

70

Fluidized wall for protecting fusion chamber walls  

DOE Patents [OSTI]

Apparatus for protecting the inner wall of a fusion chamber from microexplosion debris, x-rays, neutrons, etc. produced by deuterium-tritium (DT) targets imploded within the fusion chamber. The apparatus utilizes a fluidized wall similar to a waterfall comprising liquid lithium or solid pellets of lithium-ceramic, the waterfall forming a blanket to prevent damage of the structural materials of the chamber.

Maniscalco, James A. (Danville, CA); Meier, Wayne R. (Livermore, CA)

1982-01-01T23:59:59.000Z

71

TIP DESENSITIZATION OF AN AXIAL TURBINE ROTOR  

E-Print Network [OSTI]

flow causes total pressure loss and significantly reduces turbine stage efficiency. Tip leakage relatedCC-63 TIP DESENSITIZATION OF AN AXIAL TURBINE ROTOR USING PARTIAL SQUEALER RIMS Debashis Dey1 of full and partial-length squealer rims in a turbine stage. Full and partial-length squealer rims

Camci, Cengiz

72

meters in CO2 euthanasia chambers. All CO2 euthanasia chambers in both  

E-Print Network [OSTI]

meters in CO2 euthanasia chambers. All CO2 euthanasia chambers in both the facilities and laboratories will need flow meters. ULAR is currently in the process of identifying a cost-effective, accurate, and durable flow meter to install in all of the CO2 chambers in all of the vivaria. When a specific model

Bushman, Frederic

73

IFE Chamber Technology Testing Program In NIF and Chamber Development Test Plan Mohamed A. Abdou  

E-Print Network [OSTI]

. As ITER serves as a fusion testing facility for magnetic fusion energy (MFE) nuclear technology componentIFE Chamber Technology Testing Program In NIF and Chamber Development Test Plan Mohamed A. Abdou chamber technology testing program in NIF involoving: criteria for evaluation

Abdou, Mohamed

74

Type A: Magma-heated, Dry Steam Resource | Open Energy Information  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Type A: Magma-heated, Dry Steam Resource Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Print PDF Type A: Magma-heated, Dry Steam Resource Dictionary.png Type A: Magma-heated, Dry Steam Resource: No definition has been provided for this term. Add a Definition Brophy Occurrence Models This classification scheme was developed by Brophy, as reported in Updating the Classification of Geothermal Resources.[1] Type A: Magma-heated, Dry Steam Resource Type B: Andesitic Volcanic Resource Type C: Caldera Resource Type D: Sedimentary-hosted, Volcanic-related Resource Type E: Extensional Tectonic, Fault-Controlled Resource

75

RESEARCH ARTICLE Magma at depth: a retrospective analysis of the 1975 unrest  

E-Print Network [OSTI]

the following three decades. The area of snow-free ground in the active crater has not returned to pre, USA. In: Moran SC, Newhall CG, Roman DC (eds) Failed eruptions: Late-stage cessation of magma ascent

76

Terrestrial magma ocean solidification and formation of a candidate D" layer  

E-Print Network [OSTI]

In this thesis we investigate the solidification of early magma oceans on the Earth and the formation of a deep dense layer at the core-mantle boundary. We also study the concentrations and densities of the last layers of ...

Springmann, Alessondra

2011-01-01T23:59:59.000Z

77

Field Examples of Axial Cracked Bearings in Wind Turbine Gearboxes...  

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

Field Examples of Axial Cracked Bearings in Wind Turbine Gearboxes Presented by Paul John Baker of FrontierPro Services at the Wind Turbine Tribology Seminar 2014. 141030 Axial...

78

Piping inspection carriage having axially displaceable sensor  

DOE Patents [OSTI]

A pipe inspection instrument carriage for use with a pipe crawler for performing internal inspections of piping surfaces. The carriage has a front leg assembly, a rear leg assembly and a central support connecting the two assemblies and for mounting an instrument arm having inspection instruments. The instrument arm has a y-arm mounted distally thereon for axially aligning the inspection instrumentation and a mounting block, a linear actuator and axial movement arm for extending the inspection instruments radially outward to operably position the inspection instruments on the piping interior. Also, the carriage has a rotation motor and gear assembly for rotating the central support and the front leg assembly with respect to the rear leg assembly so that the inspection instruments azimuthally scan the piping interior. The instrument carriage allows performance of all piping inspection operations with a minimum of moving parts, thus decreasing the likelihood of performance failure.

Zollinger, William T. (Martinez, GA); Treanor, Richard C. (Augusta, GA)

1994-01-01T23:59:59.000Z

79

Axial power loss along open field lines  

SciTech Connect (OSTI)

Studies are underway to evaluate the linear mirror geometry as a candidate for a high-fluence, neutron irradiation facility. This steady-state, low-Q design is currently perceived to comprise a two-component plasma driven by neutral beams with mirror confinement of the hot ions and with no electrostatic axial reduction in the warm ion end losses. Warm-ion fueling and end-wall power density will require substantial cold plasma exterior to the mirror cell and neutral gas near the end wall. In this paper, we evaluate to what extent the loss power parallel to the axial magnetic field along open field lines is a function of the escaping plasma and end-wall parameters. By allowing the source power to depend directly on the plasma density and electron temperature, several new conclusions may be pertinent to closed field-line geometries with open field-line divertors.

Correll, D.L.

1987-08-01T23:59:59.000Z

80

Engineering design of a hypobaric plant growth chamber  

E-Print Network [OSTI]

plants with the chamber in place and removed. With the chamber removed, PAR levels were recorded as 461 []mol m?˛ s?ą; inside the complete chamber the level decreased to 408 []mol m?˛ s?ą, a difference of 11.5%....

Purswell, Joseph Lawrence

2002-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "axial magma chamber" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Virtual Design of Stirling Engine Combustion Chamber  

Science Journals Connector (OSTI)

The paper deals with the designing of a combustion chamber of the Stirling engine using the CFD approach. Virtual prototypes enabled ... . The presented results help to increase the Stirling engine efficiency tog...

Z. Kaplan; P. Novotný; V. Píšt?k

2010-01-01T23:59:59.000Z

82

Manufacturing and qualification of UHV chambers  

Science Journals Connector (OSTI)

Vacuum chambers or vacuum components that are widespread in research and in industry must fulfill high degrees of cleanliness, especially if they are required for ultra-high-vacuum (UHV) applications. It is shown...

F. Pink; G. Schmidt

2004-03-01T23:59:59.000Z

83

Neutron And Gamma Detector Using An Ionization Chamber With An...  

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

Neutron And Gamma Detector Using An Ionization Chamber Neutron And Gamma Detector Using An Ionization Chamber With An Integrated Body And Moderator A detector for detecting...

84

Cloud chamber visualization of primary cosmic rays  

SciTech Connect (OSTI)

From 1948 until 1963, cloud chambers were carried to the top of the atmosphere by balloons. From these flights, which were begun by Edward P. Ney at the University of Minnesota, came the following results: discovery of heavy cosmic ray nuclei, development of scintillation and cherenkov detectors, discovery of cosmic ray electrons, and studies of solar proton events. The history of that era is illustrated here by cloud chamber photographs of primary cosmic rays.

Earl, James A. [Department of Astronomy, University of Maryland, College Park MD (United States)

2013-02-07T23:59:59.000Z

85

Room-Temperature Operation of DC Axially Discharged Fast Axial-Flow CO Laser  

Science Journals Connector (OSTI)

A compact CO laser with a DC axially discharged fast-axial flow has been operated at room temperature (270 – 300 K), achieving ~ 165 W per unit discharge length in CW mode under xenon (Xe) gas addition. A maximum power of 385 W per unit gain length (1 m) has been similarly achieved with Xe gas at 235 – 275 K. Dependence of output power on gas-flow velocity v , discharge current I dis, and gas composition is examined experimentally and theoretically explained, and dependence of oscillation lines on v is also investigated. Moreover, the effect of gas-flow velocity on gas temperature is also examined.

Yutaka Kodama; Heihachi Sato

1996-01-01T23:59:59.000Z

86

Baroclinic tides in an axially symmetric basin  

E-Print Network [OSTI]

Energetics Returning to the governing equations (66) through (6&7) and multiplving (66) by phu?, (66) by phv?, and (67) by php?gives the result; phu?? f v?~ ? ~ ~ p S? m=O 0(, = phu?g h?o, c3 T f&hv?g o'j r SH (96) (96) aud ap? 1 a I au? I ~ ah.... Rowe (Head of Department) December 1989 ABSTRACT Baroclinic Tides in an Axially Symmetric Basin. (December 1989) Edward Paul Dever. B. S. , Texas Ag-XI University Chair ol' Advisory Committee: Prof. Robert 0. Reid A. coupled normal mode model...

Dever, Edward Paul

2012-06-07T23:59:59.000Z

87

Axial Tomography from Digitized Real Time Radiography  

DOE R&D Accomplishments [OSTI]

Axial tomography from digitized real time radiographs provides a useful tool for industrial radiography and tomography. The components of this system are: x-ray source, image intensifier, video camera, video line extractor and digitizer, data storage and reconstruction computers. With this system it is possible to view a two dimensional x-ray image in real time at each angle of rotation and select the tomography plane of interest by choosing which video line to digitize. The digitization of a video line requires less than a second making data acquisition relatively short. Further improvements on this system are planned and initial results are reported.

Zolnay, A. S.; McDonald, W. M.; Doupont, P. A.; McKinney, R. L.; Lee, M. M.

1985-01-18T23:59:59.000Z

88

Final report for NIF chamber dynamics studies  

SciTech Connect (OSTI)

The National Ignition Facility (NIF), a 1.8 MJ, 192 laser beam facility, will have anticipated fusion yields of up to 20 MJ from D-T pellets encased in a gold hohlraum target. The energy emitted from the target in the form of x rays, neutrons, target debris kinetic energy, and target shrapnel will be contained in a 5 m. radius spherical target chamber. various diagnostics will be stationed around the target at varying distances from the target. During each shot, the target will emit x rays that will vaporize nearby target facing surfaces including those of the diagnostics, the target positioner, and other chamber structures. This ablated vapor will be transported throughout the chamber, and will eventually condense and deposit on surfaces in the chamber, including the final optics debris shields. The research at the University of California at Berkeley relates primarily to the NIF chamber dynamics. The key design issues are the ablation of the chamber structures, transport of the vapor through the chamber and the condensation or deposition processes of those vaporized materials. An understanding of these processes is essential in developing a concept for protecting the fina optics debris shields from an excessive coating (> 10 A) of target debris and ablated material, thereby prolonging their lifetime between change-outs. At Berkeley, we have studied the physical issues of the ablation process and the effects of varying materials, the condensation process of the vaporized material, and design schemes that can lower the threat posed to the debris shields by these processes. The work or portions of the work completed this year have been published in several papers and a dissertation [l-5].

Burnham, A; Peterson, P F; Scott, J M

1998-09-01T23:59:59.000Z

89

40Ar-39Ar Geochronology Of Magmatic Activity, Magma Flux And Hazards At  

Open Energy Info (EERE)

Ar-39Ar Geochronology Of Magmatic Activity, Magma Flux And Hazards At Ar-39Ar Geochronology Of Magmatic Activity, Magma Flux And Hazards At Ruapehu Volcano, Taupo Volcanic Zone, New Zealand Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: 40Ar-39Ar Geochronology Of Magmatic Activity, Magma Flux And Hazards At Ruapehu Volcano, Taupo Volcanic Zone, New Zealand Details Activities (0) Areas (0) Regions (0) Abstract: We have determined precise eruption ages for andesites from Ruapehu volcano in the Tongariro Volcanic Centre of the Taupo Volcanic Zone (TVZ) using 40Ar/39Ar furnace step-heating of separated groundmass concentrates. The plateau ages indicate several eruptive pulses near 200, 134, 45, 22 and <15 ka and, based on our and previous field mapping confirm the lavas of the Te Herenga Formation as the oldest exposed part of the

90

E-Print Network 3.0 - atlas muon chambers Sample Search Results  

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

chambers Search Powered by Explorit Topic List Advanced Search Sample search results for: atlas muon chambers...

91

E-Print Network 3.0 - atlas muon chamber Sample Search Results  

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

chamber Search Powered by Explorit Topic List Advanced Search Sample search results for: atlas muon chamber...

92

Viscosity of magmas containing highly deformable bubbles M. Mangaa,*, M. Loewenbergb  

E-Print Network [OSTI]

Viscosity of magmas containing highly deformable bubbles M. Mangaa,*, M. Loewenbergb a Department The shear viscosity of a suspension of deformable bubbles dispersed within a Newtonian ¯uid is calculated. For small Ca, bubbles remain nearly spherical, and for suf®ciently large strains the viscosity of suspension

Manga, Michael

93

Pulsatory magma supply to a phonolite lava lake Clive Oppenheimer a,  

E-Print Network [OSTI]

Pulsatory magma supply to a phonolite lava lake Clive Oppenheimer a, , Alexandra S. Lomakina b processes (Tazieff, 1997; Oppenheimer et al., 2004). The decadal persistence of some lava lakes, with no net, though it may well have existed for a century or more (Oppenheimer and Kyle, 2008). Since 2001, the lake

Kingsbury, Nick

94

The effect of edifice load on magma ascent beneath a volcano  

Science Journals Connector (OSTI)

...mass and R the perfect gas constant. Finally...the vertical pro les of gas content and density. The gas phase acts to decrease...remains within the range of natural magmas, which demonstrates...Crater Lake caldera, Cascade Range, U.S.A. J...

2000-01-01T23:59:59.000Z

95

A Cosmic Ray Measurement Facility for ATLAS Muon Chambers  

E-Print Network [OSTI]

Monitored Drift Tube (MDT) chambers will constitute the large majority of precision detectors in the Muon Spectrometer of the ATLAS experiment at the Large Hadron Collider at CERN. For commissioning and calibration of MDT chambers, a Cosmic Ray Measurement Facility is in operation at Munich University. The objectives of this facility are to test the chambers and on-chamber electronics, to map the positions of the anode wires within the chambers with the precision needed for standalone muon momentum measurement in ATLAS, and to gain experience in the operation of the chambers and on-line calibration procedures. Until the start of muon chamber installation in ATLAS, 88 chambers built at the Max Planck Institute for Physics in Munich have to be commissioned and calibrated. With a data taking period of one day individual wire positions can be measured with an accuracy of 8.3 micrometers in the chamber plane and 27 micrometers in the direction perpendicular to that plane.

O. Biebel; M. Binder; M. Boutemeur; A. Brandt; J. Dubbert; G. Duckeck; J. Elmsheuser; F. Fiedler; R. Hertenberger; O. Kortner; T. Nunnemann; F. Rauscher; D. Schaile; P. Schieferdecker; A. Staude; W. Stiller; R. Stroehmer; R. Vertesi

2003-07-30T23:59:59.000Z

96

Effective Parameters in Axial Injection Suspension Plasma Spray Process  

E-Print Network [OSTI]

Effective Parameters in Axial Injection Suspension Plasma Spray Process of Alumina-structured coatings with metastable phases using significantly smaller particles as compared to conventional thermal, an alumina/ 8 wt.% yttria-stabilized zirconia was deposited by axial injection SPS process. The effects

Medraj, Mamoun

97

The Shaft Torque of a Tandem Axial-Piston Pump  

E-Print Network [OSTI]

The Shaft Torque of a Tandem Axial- Piston Pump Noah D. Manring Viral S. Mehta Mechanical of this study is to identify the best indexed position of two rotating groups within a tandem axial-piston pump characteristics of the pump, other vibration aspects of the machine are also expected to be reduced. In particular

Manring, Noah D.

98

Meson cloud contributions to baryon axial form factors  

E-Print Network [OSTI]

The axial form factor as well as the axial charge of octet baryons are studied in the perturbative chiral quark model (PCQM) with the quark wave functions predetermined by fitting the theoretical results of the proton charge form factor to experimental data. The theoretical results are found, based on the predetermined quark wave functions, in good agreement with experimental data and lattice values. This may indicate that the electric charge and axial charge distributions of the constituent quarks are the same. The study reveals that the meson cloud plays an important role in the axial charge of octet baryons, contributing 30%-40% to the total values, and strange sea quarks have a considerable contribution to the axial charge of the $\\Sigma$ and $\\Xi$.

X. Y. Liu; K. Khosonthongkee; A. Limphirat; P. Suebka; Y. Yan

2014-08-01T23:59:59.000Z

99

On-Site Wastewater Treatment Systems: Leaching Chambers  

E-Print Network [OSTI]

Leaching chambers distribute treated wastewater into the soil. This publication lists the advantages and disadvantages of leaching chamber systems, explains how to maintain them and gives estimates of costs....

Lesikar, Bruce J.

2000-02-04T23:59:59.000Z

100

Reduce Steam Trap Failures at Chambers Works  

E-Print Network [OSTI]

Ultrasonic Inspection At least 2 times per year Steam Trap Surveyor Submit reports to area management, energy team, and reliability engineers for each area every month Steam Trap Team Leader Control Plan ? Process Owner agrees...Reduce Steam Trap Failures at Chambers Works GB/BB Name: Cyndi Kouba Mentor/MBB: Andrew Degraff Team Members Michael Crowley(Site Energy Lead), (Charlie) Flanigan (Aramids-maintenance), Ben Snyder (Aramids-ATO), Michael Scruggs (Central...

Kouba, C.

Note: This page contains sample records for the topic "axial magma chamber" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Pyroclastic flows and lavas of the Mogan and Fataga formations, Tejeda Volcano, Gran Canaria, Canary Islands: mineral chemistry, intensive parameters, and magma chamber evolution  

Science Journals Connector (OSTI)

The Mogan and Fataga formations on the island of Gran Canaria, Canary Islands, represent a sequence of...3 dense-rock equivalent) including subalkaline rhyolitic, peralkaline rhyolitic and trachytic pyroclastic f...

Joy A. Crisp; Frank J. Spera

1987-01-01T23:59:59.000Z

102

E-Print Network 3.0 - axial symmetry Sample Search Results  

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

components. We also... --Analytical calculation, axial magnetization, magnetic field, permanent-magnet rings, radial magnetization. I... . The case of a magnet ring axially...

103

E-Print Network 3.0 - axially symmetric solutions Sample Search...  

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

and Rayleigh numbers close to onset of convection. Axial dipole solutions are subcritical in all... - ble the Rayleigh number the solution switches to an axial dipole...

104

E-Print Network 3.0 - axial kinetic energy Sample Search Results  

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

axial flow fan systems. Despite... -vortex-driven flow structures to increase the energy efficiency of axial flow fan systems to provide high quality... the mean kinetic...

105

Effect of an axial electric field on detonation waves.  

E-Print Network [OSTI]

??The present thesis reports an investigation of the effects of an axial electric field (200V/cm – 8000V/cm) on the propagation of detonation waves in mixtures… (more)

Kamenskihs, Vsevolods

2011-01-01T23:59:59.000Z

106

Applications of axial and radial compressor dynamic system modeling  

E-Print Network [OSTI]

The presented work is a compilation of four different projects related to axial and centrifugal compression systems. The projects are related by the underlying dynamic system modeling approach that is common in all of them. ...

Spakovszky, Zoltán S. (Zoltán Sándor), 1972-

2001-01-01T23:59:59.000Z

107

Investigation of valve plate in water hydraulic axial piston motor  

Science Journals Connector (OSTI)

This paper has introduced the developments of water hydraulic axial piston equipments. According to the effects of physico-chemical properties of water on water hydraulic components, a novel valve plate for water

Song-Lin Nie Ph.D; Zhuang-Yun Li…

2002-03-01T23:59:59.000Z

108

Lateral and Axial Capacity of Monopiles for Offshore Wind Turbines  

Science Journals Connector (OSTI)

Offshore wind has enormous worldwide potential to generate increasing ... are considered to be viable in supporting larger offshore wind turbines in shallow to medium depth waters. In ... of axial and lateral loa...

Aliasger Haiderali; Ulas Cilingir; Gopal Madabhushi

2013-09-01T23:59:59.000Z

109

Comparative assessment of five potential sites for hydrothermal-magma systems: energy transport  

SciTech Connect (OSTI)

A comparative assessment of five sites is being prepared as part of a Continental Scientific Drilling Program (CSDP) review of thermal regimes for the purpose of scoping areas for future research and drilling activities. This background report: discusses the various energy transport processes likely to be encountered in a hydrothermal-magma system, reviews related literature, discusses research and field data needs, and reviews the sites from an energy transport viewpoint. At least three major zones exist in the magma-hydrothermal transport system: the magma zone, the hydrothermal zone, and the transition zone between the two. Major energy transport questions relate to the nature and existence of these zones and their evolution with time. Additional energy transport questions are concerned with the possible existence of critical state and super-critical state permeable convection in deep geothermal systems. A review of thermal transport models emphasizes the fact that present transport models and computational techniques far outweigh the scarcity and quality of deep field data.

Hardee, H.C.

1980-09-01T23:59:59.000Z

110

CALCULATION OF PULSED KICKER MAGNETIC FIELD ATTENUATION INSIDE BEAM CHAMBERS  

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

CALCULATION OF PULSED KICKER MAGNETIC FIELD ATTENUATION CALCULATION OF PULSED KICKER MAGNETIC FIELD ATTENUATION INSIDE BEAM CHAMBERS S. H. Kim January 8, 2001 1. Introduction and Summary The ceramic beam chambers in the sections of the kicker magnets for the beam injection and extraction in the Advanced Photon Source (APS) are made of alumina. The inner surface of the ceramic chamber is coated with a conductive paste. The choice of coating thickness is intended to reduce the shielding of the pulsed kicker magnetic field while containing the electromagnetic fields due to the beam bunches inside the chamber, and minimize the Ohmic heating due to the fields on the chamber [1]. The thin coating generally does not give a uniform surface resistivity for typical dimensions of the ceramic chambers in use. The chamber cross section is a circular or

111

Vacuum chamber with a supersonic-flow aerodynamic window  

DOE Patents [OSTI]

A supersonic flow aerodynamic window is disclosed whereby a steam ejector situated in a primary chamber at vacuum exhausts superheated steam toward an orifice to a region of higher pressure, creating a barrier to the gas in the region of higher pressure which attempts to enter through the orifice. In a mixing chamber outside and in fluid communication with the primary chamber, superheated steam and gas are combined into a mixture which then enters the primary chamber through the orifice. At the point of impact of the ejector/superheated steam and the incoming gas/superheated steam mixture, a barrier is created to the gas attempting to enter the ejector chamber. This barrier, coupled with suitable vacuum pumping means and cooling means, serves to keep the steam ejector and primary chamber at a negative pressure, even though the primary chamber has an orifice to a region of higher pressure.

Hanson, C.L.

1980-10-14T23:59:59.000Z

112

Vacuum chamber with a supersonic flow aerodynamic window  

DOE Patents [OSTI]

A supersonic flow aerodynamic window, whereby a steam ejector situated in a primary chamber at vacuum exhausts superheated steam toward an orifice to a region of higher pressure, creating a barrier to the gas in the region of higher pressure which attempts to enter through the orifice. In a mixing chamber outside and in fluid communication with the primary chamber, superheated steam and gas are combined into a mixture which then enters the primary chamber through the orifice. At the point of impact of the ejector/superheated steam and the incoming gas/superheated steam mixture, a barrier is created to the gas attempting to enter the ejector chamber. This barrier, coupled with suitable vacuum pumping means and cooling means, serves to keep the steam ejector and primary chamber at a negative pressure, even though the primary chamber has an orifice to a region of higher pressure.

Hanson, Clark L. (Livermore, CA)

1982-01-01T23:59:59.000Z

113

Vacuum chamber for containing particle beams  

DOE Patents [OSTI]

A vacuum chamber for containing a charged particle beam in a rapidly changing magnetic environment comprises a ceramic pipe with conducting strips oriented along the longitudinal axis of the pipe and with circumferential conducting bands oriented perpendicular to the longitudinal axis but joined with a single longitudinal electrical connection. When both strips and bands are on the outside of the ceramic pipe, insulated from each other, a high-resistance conductive layer such as nickel can be coated on the inside of the pipe.

Harvey, A.

1985-11-26T23:59:59.000Z

114

E-Print Network 3.0 - axial flow turbines Sample Search Results  

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

turbines Search Powered by Explorit Topic List Advanced Search Sample search results for: axial flow turbines...

115

E-Print Network 3.0 - axial flow turbine Sample Search Results  

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

turbine Search Powered by Explorit Topic List Advanced Search Sample search results for: axial flow turbine...

116

E-Print Network 3.0 - axial piston pumps Sample Search Results  

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

pumps Search Powered by Explorit Topic List Advanced Search Sample search results for: axial piston pumps...

117

Measurement and Compensation of BPM Chamber Motion in HLS  

SciTech Connect (OSTI)

Significant horizontal drifts in the beam orbit in the storage ring of HLS (Hefei Light Source) have been seen for many years. What leads to the motion of Beam Position Monitor (BPM) chamber is thermal expansion mainly caused by the synchrotron light. To monitor the BPM chamber motions for all BPMs, a BPM chamber motion measurement system is built in real-time. The raster gauges are used to measure the displacements. The results distinctly show the relation between the BPM chamber motion and the beam current. To suppress the effect of BPM chamber motion, a compensation strategy is implemented at HLS. The horizontal drifts of beam orbit have been really suppressed within 20{mu}m without the compensation of BPM chamber motion in the runtime.

Li, J. W.; Sun, B. G.; Cao, Y.; Xu, H. L.; Lu, P.; Li, C.; Xuan, K.; Wang, J. G. [NSRL, School of Nuclear Science and Technology, University of Science and Technology of China Hefei, Anhui230029 (China)

2010-06-23T23:59:59.000Z

118

Tests of a Novel Design of Resistive Plate Chambers  

E-Print Network [OSTI]

A novel design of Resistive Plate Chambers (RPCs), using only a single resistive plate, is being proposed. Based on this design, two large size prototype chambers were constructed and were tested with cosmic rays and in particle beams. The tests confirmed the viability of this new approach. In addition to showing an improved single-particle response compared to the traditional 2-plate design, the novel chambers also prove to be suitable for calorimetric applications.

Bilki, B; Freund, B; Neubüser, C; Onel, Y; Repond, J; Schlereth, J; Xia, L

2015-01-01T23:59:59.000Z

119

Allan Cormack, Computerized Axial Tomography (CAT), and Magnetic Resonance  

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

Allan M. Cormack, Computerized Axial Tomography (CAT) Allan M. Cormack, Computerized Axial Tomography (CAT) and Magnetic Resonance Imaging (MRI) Resources with Additional Information magnetic resonance imaging system Computed axial tomography, commonly known as CAT scanning, was introduced in 1972. During a CAT scan, a large coil of x-ray tubes rotates around the patient's body, taking x-rays from all angles. A computer integrates all of these x-rays into a single, three-dimensional image on a television screen. The data can be saved on the computer. Allan M. Cormack, a high energy physicist at Tufts University, shared the 1979 Nobel Prize in Physiology and Medicine for his key work in developing the methods for CAT scanners. At the time of development, these methods were widely regarded as the most significant advance in medical radiography since the 1895 discovery of x-rays.

120

Axial Current Generation from Electric Field: Chiral Electric Separation Effect  

E-Print Network [OSTI]

We study a relativistic plasma containing charged chiral fermions in an external electric field. We show that with the presence of both vector and axial charge densities, the electric field can induce an axial current along its direction and thus cause chirality separation. We call it the Chiral Electric Separation Effect (CESE). On very general basis, we argue that the strength of CESE is proportional to $\\mu_V\\mu_A$ with $\\mu_V$ and $\\mu_A$ the chemical potentials for vector charge and axial charge. We then explicitly calculate this CESE conductivity coefficient in thermal QED at leading-log order. The CESE can manifest a new gapless wave mode propagating along the electric field. Potential observable of CESE in heavy-ion collisions is also discussed.

Xu-Guang Huang; Jinfeng Liao

2013-06-07T23:59:59.000Z

Note: This page contains sample records for the topic "axial magma chamber" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Isothermally heatsunk diffusion cloud chamber refrigerator  

SciTech Connect (OSTI)

This patent describes a diffusion cloud chamber isothermally heatsunk refrigerator which comprises: a heatsink consisting of two phases of a saturated substance existing in thermodynamic equilibrium at constant pressure and therefore at constant temperature, contained in a reservoir; a means of pressure damping to maintain constant pressure, as the ratio of the two phases present changes and introduces volumetric changes in the substance; a cooling member which transfer heat from vapor in contact with the cooling member surface to the ''cold side'' of a Peltier thermoelectric element with which the cooling member is in thermal contact; a Peltier thermoelectric element which removes the heat supplied by the cooling member from its ''cold side'' and pumps it to the ''hot side'' when driven by an electric current; and a means of transferring heat from the ''hot side'' of the Peltier thermoelectric element to the two-phase isothermal substance in the reservoir.

Menocal, S.G.

1987-05-05T23:59:59.000Z

122

Bubble Chambers for Experiments in Nuclear Astrophysics  

E-Print Network [OSTI]

A bubble chamber has been developed to be used as an active target system for low energy nuclear astrophysics experiments. Adopting ideas from dark matter detection with superheated liquids, a detector system compatible with gamma-ray beams has been developed. This detector alleviates some of the limitations encountered in standard measurements of the minute cross sections of interest to stellar environments. While the astrophysically relevant nuclear reaction processes at hydrostatic burning temperatures are dominated by radiative captures, in this experimental scheme we measure the time-reversed processes. Such photodisintegrations allow us to compute the radiative capture cross sections when transitions to excited states of the reaction products are negligible. Due to the transformation of phase space, the photodisintegration cross sections are up to two orders of magnitude higher. The main advantage of the new target-detector system is a density several orders of magnitude higher than conventional gas tar...

DiGiovine, B; Holt, R J; Rehm, K E; Raut, R; Robinson, A; Sonnenschein, A; Rusev, G; Tonchev, A P; Ugalde, C

2015-01-01T23:59:59.000Z

123

Concept for Reducing Hall Thruster Chamber Wall Erosion with...  

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

Concept for Reducing Hall Thruster Chamber Wall Erosion with Lithium Vapor Shielding. Hall thrusters have been established as a compact and reliable means for satellite...

124

Dielectric liquid ionization chambers for detecting fast neutrons  

E-Print Network [OSTI]

Three ionization chambers with different geometries have been constructed and filled with dielectric liquids for detection of fast neutrons. The three dielectric liquids studied were Tetramethylsilane (TMS), Tetramethylpentane ...

Boyd, Erin M

2008-01-01T23:59:59.000Z

125

Axial xenon stability considerations in VVER-1000 reactors  

SciTech Connect (OSTI)

Frequent problems experienced in VVER-1000 reactors with xenon oscillation control have been reported. Modern Pressurized Water Reactors (PWRs) are designed with operational strategies to help avoid such axial xenon oscillations. Uncontrolled xenon oscillations can cause operational problems, requiring frequent operator intervention and leading to power reductions (or plant trips) due to high core peaking factors, thereby reducing overall plant capacity factors. In the worst case, an uncontrolled xenon oscillation can lead to violations of safety requirements on pellet clad interaction (PCI), departure from nucleate boiling or fuel centerline melting if the plant does not have adequate safety protection systems that account for limiting axial power distributions.

Doshi, P.K.; Miller, R.W.

1993-12-31T23:59:59.000Z

126

Parallel plate avalanche chamber as an endcap detector for Time Projection Chamber  

SciTech Connect (OSTI)

A small, 10 x 10 cm/sup 2/, parallel plate avalanche counter has been tested paying special attention to those features which can be important in the Time Projection Chamber. The structure of the test chamber is shown. It has a conversion and drift volume, 11 mm thick, delimited by two stainless steel cross wire grids, of 100 ..mu..m wire diameter and 500 ..mu..mm pitch, identified by HV1 and HV2. The anode is made of thick wires, 100 ..mu..m in diameter spaced every 500 ..mu..m. The amplification gap is 4 mm thick. Below the anode, 1 mm apart, we have paced an identical wire plane, HV4, with wires perpendicular to the anode wires. Both electrodes are equipped with electronics and read out. All measurements were performed with a mixture of argon and methane (83% - 17%), a typical gas for Time Projection Chambers. A multiplication factor up to 10/sup 5/ was attained.

Peisert, A.

1984-01-01T23:59:59.000Z

127

Mathematical model of material kinematics in an axial threshing unit  

Science Journals Connector (OSTI)

This paper presents a study of the movement of vegetal material through the threshing space of an axial threshing unit. The developed kinematical equations are based on a nonlinear law governing the non-uniform movement of the material on an uneven helical ... Keywords: Combine harvester, Computer simulation, Grain Kinematics, Grain Separation, Modeling

Petre I. Miu; Heinz-Dieter Kutzbach

2007-09-01T23:59:59.000Z

128

Purification, Ultrastructure, and Composition of Axial Filaments from Leptospira  

Science Journals Connector (OSTI)

...typical procaryotic nuclear region. The axial filament...FILAMENTS Denton DV-502 vacuum evaporator with carbon...tetramethylethylenediamine as accelerator in 12 ml of 0.05 M...typical procaryotic nuclear region (Fig. 4...glutaraldehyde-prefixed cells this nuclear region was not apparent...

Robert K. Nauman; Stanley C. Holt; C. D. Cox

1969-04-01T23:59:59.000Z

129

Overview of Chamber and Power Plant Designs for IFE  

E-Print Network [OSTI]

, to be published in 2011, (ISBN 9780470894392) I will review some of the more complete integrated design studies&E are choice of materials, chamber and building design, tritium inventory, design of tritium processing systemsOverview of Chamber and Power Plant Designs for IFE Wayne Meier Deputy Program Leader Fusion Energy

130

Heart chambers and whole heart segmentation techniques: review  

E-Print Network [OSTI]

Heart chambers and whole heart segmentation techniques: review Dongwoo Kang Jonghye Woo Piotr J://electronicimaging.spiedigitallibrary.org/ on 01/15/2014 Terms of Use: http://spiedl.org/terms #12;Heart chambers and whole heart segmentation, and reproducible segmentation methods. Figure 1 illustrates an example of segmentation of heart on CT scan. A

Kuo, C.-C. "Jay"

131

NIF Target Chamber Dedicated | National Nuclear Security Administration  

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

NIF Target Chamber Dedicated | National Nuclear Security Administration NIF Target Chamber Dedicated | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Continuing Management Reform Countering Nuclear Terrorism About Us Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Media Room Congressional Testimony Fact Sheets Newsletters Press Releases Speeches Events Social Media Video Gallery Photo Gallery NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog Home > About Us > Our History > NNSA Timeline > NIF Target Chamber Dedicated NIF Target Chamber Dedicated June 11, 1999 Livermore, CA NIF Target Chamber Dedicated Secretary Richardson dedicates the National Ignition Facility target

132

A mechanical mode-stirred reverberation chamber with chaotic geometry  

E-Print Network [OSTI]

A previous research on multivariate approach to the calculation of reverberation chamber correlation matrices is used to calculate the number of independent positions in a mode-stirred reverberation chamber. Anomalies and counterintuitive behavior are observed in terms of number of correlated matrix elements with respect to increasing frequency. This is ascribed to the regular geometry forming the baseline cavity (screened room) of a reverberation chamber, responsible for localizing energy and preserving regular modes (bouncing ball modes). Smooth wall deformations are introduced in order to create underlying Lyapunov instability of rays and then destroy survived regular modes. Numerical full-wave simulations are performed for a reverberation chamber with corner hemispheres and (off-)center wall spherical caps. Field sampling is performed by moving a mechanical carousel stirrer. It is found that wave-chaos inspired baseline geometries improve chamber performances in terms of lowest usable frequencies and number of independent cavity realizations of mechanical stirrers.

Gabriele Gradoni; Franco Moglie; Valter Mariani Primiani

2014-07-06T23:59:59.000Z

133

The Fine Gold Intrusive Suite: The roles of basement terranes and magma source development in the Early Cretaceous Sierra Nevada batholith  

Science Journals Connector (OSTI)

...conduitsa to refer to the feeder networks that relay magma from sources to the sites where the magmas crystallize...oceanic basalt and sediment in generating the Hfa Nd mantle array: Nature Geoscience, v. 1, p. 64a 67, doi: 10...Plank T., Prytulak J. , 2011, The Hfa Nd isotopic composition of marine sediments...

Jade Star Lackey; M. Robinson Cecil; Cameron J. Windham; Ryan E. Frazer; Ilya N. Bindeman; George E. Gehrels

134

Vacuum chamber for ion manipulation device  

DOE Patents [OSTI]

An ion manipulation method and device is disclosed. The device includes a pair of substantially parallel surfaces. An array of inner electrodes is contained within, and extends substantially along the length of, each parallel surface. The device includes a first outer array of electrodes and a second outer array of electrodes. Each outer array of electrodes is positioned on either side of the inner electrodes, and is contained within and extends substantially along the length of each parallel surface. A DC voltage is applied to the first and second outer array of electrodes. A RF voltage, with a superimposed electric field, is applied to the inner electrodes by applying the DC voltages to each electrode. Ions either move between the parallel surfaces within an ion confinement area or along paths in the direction of the electric field, or can be trapped in the ion confinement area. A predetermined number of pairs of surfaces are disposed in one or more chambers, forming a multiple-layer ion mobility cyclotron device.

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

2014-12-09T23:59:59.000Z

135

European Fusion Theory Conference Non-local features of transport in the axial tokamak region  

E-Print Network [OSTI]

9th European Fusion Theory Conference Non-local features of transport in the axial tokamak region J effects in the axial region of an axi- symmetric tokamak equilibrium. The starting point is the guiding

136

Effective parameters in axial injection suspension plasma spray process of alumina-zirconia ceramics  

E-Print Network [OSTI]

Effective parameters in axial injection suspension plasma spray process of alumina- zirconia phases using extra small particles as compared to conventional thermal spraying. Suspension spraying% yittria stabilized zirconia was deposited by axial injection SPS process. The effects of principal

Medraj, Mamoun

137

E-Print Network 3.0 - axial-flow ventricular assist Sample Search...  

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

and multi- anode PMT array (bottom). Figure 10b. High velocity axial flow with single spheromak (v 100 km... of the bidirectional jet Figure 11b. Mean axial flow at the midplane...

138

E-Print Network 3.0 - axial crush response Sample Search Results  

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

model predicts well the stress-strain response ofFRP confined concrete. 7. The axial... Behavior of Concrete-Filled FRP Tubes Under Bending, Axial Loads, and Combined Loading...

139

Integral and axial xenon oscillations superposition and vver-1000 core energy-release stability  

Science Journals Connector (OSTI)

The effects arising from the interaction between the xenon oscillations of the power and the axial distribution ... . The superposition of the integral and axial xenon oscillations combined with the operation of ...

S. P. Averyanova; A. A. Dubov; P. E. Filimonov

2011-11-01T23:59:59.000Z

140

New data reflect on the thermal antiquity of the Socorro magma body locale, Rio Grande Rift, New Mexico  

Science Journals Connector (OSTI)

...uplift of the Socorro magma body, in Lueth V.W., Lucas S.G., Chamberlin R.M., eds., Geology of the Chupadera Mesa Region: Socorro, New Mexico Geological Society, 60th Annual Field Conference Guidebook, p. 415a 424. a µ Touloukain...

Marshall Reiter; Richard M. Chamberlin; David W. Love

Note: This page contains sample records for the topic "axial magma chamber" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Turbine component cooling channel mesh with intersection chambers  

DOE Patents [OSTI]

A mesh (35) of cooling channels (35A, 35B) with an array of cooling channel intersections (42) in a wall (21, 22) of a turbine component. A mixing chamber (42A-C) at each intersection is wider (W1, W2)) than a width (W) of each of the cooling channels connected to the mixing chamber. The mixing chamber promotes swirl, and slows the coolant for more efficient and uniform cooling. A series of cooling meshes (M1, M2) may be separated by mixing manifolds (44), which may have film cooling holes (46) and/or coolant refresher holes (48).

Lee, Ching-Pang; Marra, John J

2014-05-06T23:59:59.000Z

142

Axially Tapered And Bilayer Microchannels For Evaporative Cooling Devices  

DOE Patents [OSTI]

The invention consists of an evaporative cooling device comprising one or more microchannels whose cross section is axially reduced to control the maximum capillary pressure differential between liquid and vapor phases. In one embodiment, the evaporation channels have a rectangular cross section that is reduced in width along a flow path. In another embodiment, channels of fixed width are patterned with an array of microfabricated post-like features such that the feature size and spacing are gradually reduced along the flow path. Other embodiments incorporate bilayer channels consisting of an upper cover plate having a pattern of slots or holes of axially decreasing size and a lower fluid flow layer having channel widths substantially greater than the characteristic microscale dimensions of the patterned cover plate. The small dimensions of the cover plate holes afford large capillary pressure differentials while the larger dimensions of the lower region reduce viscous flow resistance.

Nilson, Robert (Cardiff, CA); Griffiths, Stewart (Livermore, CA)

2005-10-04T23:59:59.000Z

143

Axial Ge/Si nanowire heterostructure tunnel FETs  

SciTech Connect (OSTI)

The vapor-liquid-solid (VLS) growth of semiconductor nanowires allows doping and composition modulation along their axis and the realization of axial 1 D heterostructures. This provides additional flexibility in energy band-edge engineering along the transport direction which is difficult to attain by planar materials growth and processing techniques. We report here on the design, growth, fabrication, and characterization of asymmetric heterostructure tunnel field-effect transistors (HTFETs) based on 100% compositionally modulated Si/Ge axial NWs for high on-current operation and low ambipolar transport behavior. We discuss the optimization of band-offsets and Schottky barrier heights for high performance HTFETs and issues surrounding their experimental realization. Our HTFET devices with 10 nm PECVD SiN{sub x} gate dielectric resulted in a measured current drive exceeding 100 {mu}A/{mu}m (I/{pi}D) and 10{sup 5} I{sub on}/I{sub off} ratios.

Picraux, Sanuel T [Los Alamos National Laboratory; Daych, Shadi A [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

144

Chiral Structure of Vector and Axial-Vector Tetraquark Currents  

E-Print Network [OSTI]

We investigate the chiral structure of local vector and axial-vector tetraquark currents, and study their chiral transformation properties. We consider the charge-conjugation parity and classify all the isovector vector and axial-vector local tetraquark currents of quantum numbers I(G)J(PC)=1(-)1(-+), I(G)J(PC)=1(+)1(--), I(G)J(PC)=1(-)1(++) and I(G)J(PC)=1(+)1(+-). We find that there is a one to one correspondence among them. Using these currents, we perform QCD sum rule analyses. Our results suggest that there is a missing b1 state having I(G)J(PC)=1(+)1(+-) and a mass around 1.47-1.66 GeV.

Hua-Xing Chen

2013-11-20T23:59:59.000Z

145

A Comparative Study of Modular Axial Flux Podded Generators for Marine Current Turbines  

E-Print Network [OSTI]

for MCTs. For that purpose, a comparative study is proposed, to assess modular axial flux permanent magnet current turbine, axial flux permanent magnet generator, design, optimization. Nomenclature MCT = Marine Current Turbine; AFPM = Axial Flux Permanent Magnet. I. Introduction Marine energy has become an issue

Brest, Université de

146

Long-term survival of the axial valley morphology at abandoned slow-spreading centers  

E-Print Network [OSTI]

Long-term survival of the axial valley morphology at abandoned slow-spreading centers Andrew M the preservation of prominent axial valleys at extinct spreading centers, where extension has long ceased. In other of mid-ocean ridges suggest that the axial valley topography created at active slow- spreading centers

Freed, Andrew

147

Ambipolar potential formation and axial confinement in TMX  

Science Journals Connector (OSTI)

TMX experimental data on ambipolar potential control and on the accompanying electrostatic confinement are reported. In the radial core of the central cell, measurements of electrostatic potentials of 150 V which augment axial ion confinement are in agreement with predictions using the Maxwell-Boltzmann result. Central-cell ion confinement was observed to scale according to electrostatic potential theory up to average enhancement factors of eight times over mirror confinement alone.

D.L. Correll; S.L. Allen; T.A. Capser; J.F. Clauser; P. Coakley; F.H. Coensgen; W. Condit; W.F. Cummins; J.C. Davis; R.P. Drake; J.H. Foote; A.H. Futch; R.K. Goodman; D.P. Grubb; G.A. Hallock; E.B. Hooper; R.S. Hornady; A.L. Hunt; C.V. Karmendy; A.W. Molvik; W.E. Nexsen; W.L. Pickles; P. Poulsen; T.C. Simonen; B.W. Stallard; O.T. Strand

1982-01-01T23:59:59.000Z

148

Coral Extension Rate Analysis Using Computed Axial Tomography  

E-Print Network [OSTI]

CORAL EXTENSION RATE ANALYSIS USING COMPUTED AXIAL TOMOGRAPHY A Thesis by ELEANOR ANN YUDELMAN Submitted to the Office of Graduate and Professional Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE Chair of Committee, Niall Slowey Committee Members, Deborah Thomas Benjamin Giese George P. Schmahl Head of Department, Deborah Thomas May 2014 Major Subject: Oceanography Copyright 2014 Eleanor Ann Yudelman ii ABSTRACT...

Yudelman, Eleanor Ann

2014-01-10T23:59:59.000Z

149

QN_CloudChamberV1.4  

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

How to Build a Cosmic-Ray Cloud Chamber How to Build a Cosmic-Ray Cloud Chamber October 2008, Version 1.4 * QuarkNet version. Fermi National Accelerator Laboratory. * Instructions written by Jeremy Paschke, York High School and Anne Mary Teichert, Fermilab. * Model initially designed and built by Robert Peterson, Fermilab. If you have further questions, or improvements of your own you would like to share with the QuarkNet group, please contact: Jeremy Paschke, York High School Physics Instructor (jpaschke@elmhurst205.org), or Bob Peterson, Fermilab Education Specialist, (rspete@fnal.gov). Justification: Showing your class a working cloud chamber is one of the best ways to generate student interest in modern physics. The cloud chamber described below will display natural background radiation (muons generated by

150

Mini-chamber, an advanced protection concept for NIF  

SciTech Connect (OSTI)

Inertial confinement fusion (ICF) target debris and ablated near-target materials pose the primary threat to the National Ignition Facility (NIF) final optics debris shields, as well as a major challenge in future inertial fusion energy (IFE) power plants. This work discusses a NIF `mini-chamber,` designed to mitigate the debris threat. Although the NIF base-line design protects against debris using a frost-protected target positioner and refractory first-wall coatings, the mini-chamber provides important flexibility in three areas: debris-shield protection from beyond-design basis shots (i.e. heavy hohlraums, special diagnostics, shields); fielding of large experiments with significant surface ablation; and studying key ablation and gas-dynamics issues for liquid-wall IFE power plants. Key mini-chamber modeling results are presented, followed by discussion of equipment requirements for fielding a NIF mini-chamber. 7 refs., 3 figs.

Peterson, P.F.; Scott, J.M. [Univ. of California, Berkeley, CA (United States)

1996-12-31T23:59:59.000Z

151

Velocity of the electric arc in a plasmatron discharge chamber  

Science Journals Connector (OSTI)

An experimental investigation of the velocity of a high-current arc with air injection in the discharge chamber of a coaxial sectioned plasmatron is described. The experiments showed that the velocity of the c...

A. S. Shaboltas

1969-09-01T23:59:59.000Z

152

Carrying Semiautomatic Pistols with a Round in the Chamber  

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

Sets forth requirements for a DOE security police officer who must carry a round in the chamber of a semiautomatic pistol while on duty. Does not cancel other directives.

1999-10-28T23:59:59.000Z

153

E-Cloud Build-up in Grooved Chambers  

E-Print Network [OSTI]

and F. Zimmermann, ”LC e-Cloud Activities at CERN”, talkal. , Simulations of the Electron Cloud for Vari- ous Con?E-CLOUD BUILD-UP IN GROOVED CHAMBERS ? M. Venturini † LBNL,

Venturini, Marco

2007-01-01T23:59:59.000Z

154

DIMUON PRODUCTION BY HIGH ENERGY NEUTRINOS AND ANTINEUTRINOS IN THE FERMILAB FIFTEEN-FOOT BUBBLE CHAMBER  

E-Print Network [OSTI]

ANTINEUTRINOS IN THE FERMILAB FIFTEEN-FOOT BUBBLE CHAMBERANTINEUTRINOS IN THE FERMILAB FIFTEEN-FOOT BUBBLE CHAMBER*ANTINEUTRINOS IN THE FERMILAB FIFTEEN-FOOT BUBBLE CHAMBER

Orthel, John L.

2010-01-01T23:59:59.000Z

155

E-Print Network 3.0 - atmospheric exposure chambers Sample Search...  

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

Topic List Advanced Search Sample search results for: atmospheric exposure chambers Page: << < 1 2 3 4 5 > >> 1 Dynamic Chamber System to Measure Gaseous Compounds Emissions...

156

Laser calibration system for the CERES Time Projection Chamber  

E-Print Network [OSTI]

A Nd:YAG laser was used to simulate charged particle tracks at known positions in the CERES Time Projection Chamber at the CERN SPS. The system was primarily developed to study the response of the readout electronics and to calibrate the electron drift velocity. Further applications were the determination of the gating grid transparency, the chamber position calibration, and long-term monitoring of drift properties of the gas in the detector.

Dariusz Miskowiec; Peter Braun-Munzinger

2008-02-15T23:59:59.000Z

157

Transverse wakefields due to asymmetric protrusions into a vacuum chamber  

Science Journals Connector (OSTI)

Abstract We analyze the effect of a wakefield caused by an asymmetric protrusion inside the accelerator vacuum chamber. The asymmetry leads to a transverse kick on the beam and an increase of the projected transverse beam emittance. Calculations are done for a model rectangular protrusion in a vacuum chamber of rectangular cross-section. Based on our analysis, numerical estimates are given for the SuperKEKB accelerator in KEK, Japan, and TLEP-W proposal at CERN.

Gennady Stupakov; Demin Zhou

2014-01-01T23:59:59.000Z

158

SUMMARY ON TITANIUM NITRIDE COATING OF SNS RING VACUUM CHAMBERS.  

SciTech Connect (OSTI)

The inner surfaces of the 248 m Spallation Neutron Source (SNS) accumulator ring vacuum chambers are coated with {approx}100nm of titanium nitride (TiN) to reduce the secondary electron yield (SEY) of the chamber walls. There are approximately 135 chambers and kicker modules, some up to 5m in length and 36cm in diameter, coated with TiN. The coating is deposited by means of reactive DC magnetron sputtering -using a - cylindrical cathode with internal permanent magnets. This cathode configuration generates a deposition-rate sufficient to meet the required production schedule and produces stoichiometric films with good adhesion, low SEY and acceptable outgassing. Moreover, the cathode magnet configuration allows for simple changes in length and has been adapted to coat the wide variety of chambers and components contained within the arcs, injection, extraction, collimation and RF straight sections. Chamber types and quantities as well as the cathode configurations are presented herein. The unique coating requirements of the injection kicker ceramic chambers and the extraction kicker ferrite surface will be emphasized. A brief summary of the salient coating properties is given including the interdependence of SEY as a function of surface roughness and its effect on outgassing.

TODD, R.; HE, P.; HSEUH, H.C.; WEISS, D.

2005-05-16T23:59:59.000Z

159

Performance of tubular members under cyclic axial loads  

SciTech Connect (OSTI)

In this paper the behavior of pin-ended tubular steel members under cyclic axial loads is studied by using Finite Element Method (FEM) considering both geometrical and material non-linearities. The factors considered in this study are the cyclic loading characteristics (displacement amplitude and mean displacement), geometrical parameters (diameter-to-thickness ratio D/t and normalized slenderness ratio {lambda}) and inelastic characteristics of the material. The results of numerical analysis are closely examined with respect to both ultimate strength and energy dissipation capacity.

Shaker, R.E.; Murakawa, Hidekazu; Ueda, Yukio [Osaka Univ. (Japan)

1995-12-31T23:59:59.000Z

160

Axial clad strain behavior of sphere-pac fuel pins  

E-Print Network [OSTI]

areas; irradiation per for mance and fuel manufactur e. In instr umented ir r ad i ation tests, the axial strain behavior of' spher e-pac fuel pins is markedly differ ent than that of refer ence pellet pins. In initial star tup power ramps, the clad...'s results indicate that, for ver y high levels of applied str ess (5000 psia), less than 3$ of c remained as ch&. vc The plunger-cladding assembly friction terms, a and b, were neglected. Exact deter mination of these values was impossible with the test...

Thomas, James Kelly

2012-06-07T23:59:59.000Z

Note: This page contains sample records for the topic "axial magma chamber" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Source components of the Gran Canaria (Canary Islands) shield stage magmas: evidence from olivine composition and Sr–Nd–Pb isotopes  

Science Journals Connector (OSTI)

The Canary Island primitive basaltic magmas are thought to be derived from an HIMU-type upwelling mantle containing isotopically depleted (NMORB)-type component having interacted with an enriched (EM)-type com...

Andrey A. Gurenko; Kaj A. Hoernle…

2010-05-01T23:59:59.000Z

162

Reanalysis of bubble chamber measurements of muon-neutrino induced single pion production  

E-Print Network [OSTI]

There exists a longstanding disagreement between bubble chamber measurements of the single pion production channel $\

Callum Wilkinson; Philip Rodrigues; Susan Cartwright; Lee Thompson; Kevin McFarland

2014-11-17T23:59:59.000Z

163

Reanalysis of bubble chamber measurements of muon-neutrino induced single pion production  

E-Print Network [OSTI]

There exists a longstanding disagreement between bubble chamber measurements of the single pion production channel $\

Wilkinson, Callum; Cartwright, Susan; Thompson, Lee; McFarland, Kevin

2014-01-01T23:59:59.000Z

164

Initial Back-to-Back Fission Chamber Testing in ATRC  

SciTech Connect (OSTI)

Development and testing of in-pile, real-time neutron sensors for use in Materials Test Reactor experiments is an ongoing project at Idaho National Laboratory. The Advanced Test Reactor National Scientific User Facility has sponsored a series of projects to evaluate neutron detector options in the Advanced Test Reactor Critical Facility (ATRC). Special hardware was designed and fabricated to enable testing of the detectors in the ATRC. Initial testing of Self-Powered Neutron Detectors and miniature fission chambers produced promising results. Follow-on testing required more experiment hardware to be developed. The follow-on testing used a Back-to-Back fission chamber with the intent to provide calibration data, and a means of measuring spectral indices. As indicated within this document, this is the first time in decades that BTB fission chambers have been used in INL facilities. Results from these fission chamber measurements provide a baseline reference for future measurements with Back-to-Back fission chambers.

Benjamin Chase; Troy Unruh; Joy Rempe

2014-06-01T23:59:59.000Z

165

Competition between modes with different axial structures in gyrotrons  

SciTech Connect (OSTI)

This study was motivated by some experiments in which it was found that during the voltage rise, instead of expected excitation of a high-frequency parasitic mode, the excitation of a lower-frequency parasitic mode takes place in a certain range of voltages. For explaining this fact, the dependence of start currents of possible competing modes on the beam voltage was carried out in the cold-cavity approximation and by using the self-consistent approach. It was found that in the case of cavities, which consist of the combination of a section of constant radius waveguide and a slightly uptapered waveguide, these two approaches yield completely different results. Thus, experimentally observed excitation of the low-frequency parasitic mode can be explained by the self-consistent modification of the axial profile of the excited field, which has strong influence on the diffractive quality factor of competing modes. This modification is especially pronounced in the case of excitation of modes with many axial variations which can be excited in the region of beam interaction with the backward-wave component of such modes.

Khutoryan, Eduard M. [O. Ya. Usikov Institute for Radiophysics and Electronics, 12, Proskura str., Kharkiv 61085 (Ukraine); Nusinovich, Gregory S.; Sinitsyn, Oleksandr V. [Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742-3511 (United States)

2014-09-15T23:59:59.000Z

166

Axial Ge/Si nanowire heterostructure tunnel FETs.  

SciTech Connect (OSTI)

Axial Ge/Si heterostructure nanowires (NWs) allow energy band-edge engineering along the axis of the NW, which is the charge transport direction, and the realization of asymmetric devices for novel device architectures. This work reports on two significant advances in the area of heterostructure NWs and tunnel FETs: (i) the realization of 100% compositionally modulated Si/Ge axial heterostructure NWs with lengths suitable for device fabrication and (ii) the design and implementation of Schottky barrier tunnel FETs on these NWs for high-on currents and suppressed ambipolar behavior. Initial prototype devices with 10 nm PECVD SiN{sub x} gate dielectric resulted in a very high current drive in excess of 100 {micro}A/{micro}m (I/{pi}D) and 10{sup 5} I{sub on}/I{sub off} ratios. Prior work on the synthesis of Ge/Si axial NW heterostructures through the VLS mechanism have resulted in axial Si/Si{sub 1-x}Ge{sub x} NW heterostructures with x{sub max} {approx} 0.3, and more recently 100% composition modulation was achieved with a solid growth catalyst. In this latter case, the thickness of the heterostructure cannot exceed few atomic layers due to the slow axial growth rate and concurrent radial deposition on the NW sidewalls leading to a mixture of axial and radial deposition, which imposes a big challenge for fabricating useful devices form these NWs in the near future. Here, we report the VLS growth of 100% doping and composition modulated axial Ge/Si heterostructure NWs with lengths appropriate for device fabrication by devising a growth procedure that eliminates Au diffusion on the NW sidewalls and minimizes random kinking in the heterostructure NWs as deduced from detailed microscopy analysis. Fig. 1 a shows a cross-sectional SEM image of epitaxial Ge/Si axial NW heterostructures grown on a Ge(111) surface. The interface abruptness in these Ge/Si heterostructure NWs is of the order of the NW diameter. Some of these NWs develop a crystallographic kink that is {approx}20{sup o} off the <111> axis at about 300 nm away from the Ge/Si interface. This provides a natural marker for placing the gate contact electrodes and gate metal at appropriate location for desired high-on current and reduced ambipolarity as shown in Fig. 2. The 1D heterostructures allow band-edge engineering in the transport direction, not easily accessible in planar devices, providing an additional degree of freedom for designing tunnel FETs (TFETs). For instance, a Ge tunnel source can be used for efficient electron/hole tunneling and a Si drain can be used for reduced back-tunneling and ambipolar behavior. Interface abruptness on the other hand (particularly for doping) imposes challenges in these structures and others for realizing high performance TFETs in p-i-n junctions. Since the metal-semiconductor contacts provide a sharp interface with band-edge control, we use properly designed Schottky contacts (aided by 3D Silvaco simulations) as the tunnel barriers both at the source and drain and utilize the asymmetry in the Ge/Si channel bandgap to reduce ambipolar transport behavior generally observed in TFETs. Fig. 3 shows the room-temperature transfer curves of a Ge/Si heterostructure TFET (H-TFET) for different V{sub DS} values showing a maximum on-current of {approx}7 {micro}A, {approx}170 mV/decade inverse subthreshold slope and 5 orders of magnitude I{sub on}/I{sub off} ratios for all V{sub DS} biases considered here. This high on-current value is {approx}1750 X higher than that obtained with Si p-i-n{sup +} NW TFETs and {approx}35 X higher than that obtained with CNT TFET. The I{sub on}/I{sub off} ratio and inverse subthreshold slope compare favorably to that of Si {approx} 10{sup 3} I{sub on}/I{sub off} and {approx} 800 mV/decade SS{sup -1} but lags behind those of CNT TFET due to poor PECVD nitride gate oxide quality ({var_epsilon}{sub r} {approx} 3-4). The asymmetry in the Schottky barrier heights used here eliminates the stringent requirements of abrupt doped interfaces used in p-i-n based TFETs, which is hard to achieve both in thin-film and

Dayeh, Shadi A. (Los Alamos National Laboratory); Gin, Aaron V.; Huang, Jian Yu; Picraux, Samuel Thomas (Los Alamos National Laboratory)

2010-03-01T23:59:59.000Z

167

Federation of Indian Chambers of Commerce & Industry (FICCI) | Department  

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

Federation of Indian Chambers of Commerce & Industry (FICCI) Federation of Indian Chambers of Commerce & Industry (FICCI) Federation of Indian Chambers of Commerce & Industry (FICCI) March 20, 2007 - 11:37am Addthis Thank you Geoff (Pyatt) for that introduction. I'd like to thank FICCI for hosting this event and thank its leadership for their kind words. I'm very pleased to be here in India - and to be with all of you today. Since his very first days in office, President Bush has considered growing and strengthening the United States' bilateral relationship with India to be a top priority. The shared commitment of President Bush and Prime Minister Singh to building our relationship was evidenced by the historic strategic partnership initiatives announced during the President's visit here in March of last year.

168

Challenge Met as APS Sends Final Chambers to LCLS  

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

A Marriage of Hardware and Hard Work A Marriage of Hardware and Hard Work Shaken but Not Stirred 2008 Rosalind Franklin Young Investigator Award The 2008 3-Way Meeting In R&D, Super X-rays Mark Many Spots APS News Archives: 2012 | 2011 | 2010 | 2009 2008 | 2007 | 2006 | 2005 2004 | 2003 | 2002 | 2001 2000 Subscribe to APS News rss feed Challenge Met as APS Sends Final Chambers to LCLS MAY 21, 2008 Bookmark and Share The final five (of 40) extruded aluminum vacuum chambers for the Linac Coherent Light Source (LCLS) undulator system have been shipped from Argonne National Laboratory - where the chambers were designed and assembled - to the Stanford Linear Accelerator Center, where the LCLS "will be the world's first x-ray free electron laser when it becomes operational in 2009. Pulses of x-ray laser light from LCLS will be many

169

Single-molecule mobility in confined and crowded femtoliter chambers  

SciTech Connect (OSTI)

The effects of increased crowding and confinement on the mobility of individual fluorescent molecules were studied using Fluorescence Correlation Spectroscopy (FCS) in a microfluidic device with sealable femtoliter-volume chambers, and compared to three dimensional stochastic Monte Carlo simulations. When crowding and the degree of confinement were increased simultaneously, extended correlation times of fluorescent intensity fluctuations were observed with FCS compared to varying either crowding or confinement alone. Both experimental data and simulation suggest these extended correlation times were due to increased fluorophore adsorption-desorption events at the chamber lid in the presence of crowders. The data in increasingly confined and crowded chambers described here captures some of the salient features of crowding in cell-like environments.

Collier, Pat [ORNL; Fowlkes, Jason Davidson [ORNL

2013-01-01T23:59:59.000Z

170

Ionisation Chambers for the LHC Beam Loss Detection  

E-Print Network [OSTI]

At the Large Hadron Collider (LHC) a beam loss system will be used to prevent and protect superconducting magnets against coil quenches and coil damages. Since the stored particle beam intensity is 8 orders of magnitude larger than the lowest quench level value particular attention is paid to the design of the secondary particle shower detectors. The foreseen ionisation chambers are optimised in geometry simulating the probable loss distribution along the magnets and convoluting the loss distribution with the secondary particle shower distributions. To reach the appropriate coverage of a particle loss and to determine the quench levels with a relative accuracy of 2 the number of the detectors and their lengths is weighted against the particle intensity density variation. In addition attention is paid to the electrical ionisation chamber signal to minimise the ion tail extension. This optimisation is based on time resolved test measurements in the PS booster. A proposal for a new ionisation chamber will be pre...

Gschwendtner, E; Dehning, B; Ferioli, G; Kain, V

2003-01-01T23:59:59.000Z

171

Small-scale mantle heterogeneity on the source of the Gran Canaria (Canary Islands) Pliocene–Quaternary magmas  

Science Journals Connector (OSTI)

New chemical and Sr–Nd–Pb isotopic data of the Plio-Quaternary mafic lavas of Gran Canaria are used to investigate their mantle source composition. The most prominent aspects of the new dataset are the slight isotopic differences between the Plio-Quaternary (Post-Roque Nublo Group) and the older Pliocene (Roque Nublo Group) mafic parental magmas, which reflect small-scale mantle heterogeneities. Melting of two mantle materials, one isotopically more depleted and similar to the Depleted Mantle (DM) and the other with more radiogenic Pb-isotope ratios comparable to a mantle with high U/Pb ratio (HIMU), accounts for the isotopic and trace element composition of the Pliocene–Quaternary magmas of Gran Canaria. Geochemical variations show that the Pliocene–Quaternary mantle source is compositionally and lithologically heterogeneous and supports the presence of a silica-deficient pyroxenite mantle component. The contribution of the pyroxenite component in the generation of the Roque Nublo and Post-Roque Nublo magmas is estimated to be in the range from 50 to 70%. Trace element ratios support mixing between the two mantle components (pyroxenite veins in a peridotite matrix) which obscure the original chemical and isotopic composition of these two end-members.

M. Aulinas; D. Gimeno; J.L. Fernandez-Turiel; L. Font; F.J. Perez-Torrado; A. Rodriguez-Gonzalez; G.M. Nowell

2010-01-01T23:59:59.000Z

172

Matrix Algebra for GPU and Multicore Architectures (MAGMA) for Large Petascale Systems  

SciTech Connect (OSTI)

The goal of the MAGMA project is to create a new generation of linear algebra libraries that achieve the fastest possible time to an accurate solution on hybrid Multicore+GPU-based systems, using all the processing power that future high-end systems can make available within given energy constraints. Our efforts at the University of Tennessee achieved the goals set in all of the five areas identified in the proposal: 1. Communication optimal algorithms; 2. Autotuning for GPU and hybrid processors; 3. Scheduling and memory management techniques for heterogeneity and scale; 4. Fault tolerance and robustness for large scale systems; 5. Building energy efficiency into software foundations. The University of Tennessee’s main contributions, as proposed, were the research and software development of new algorithms for hybrid multi/many-core CPUs and GPUs, as related to two-sided factorizations and complete eigenproblem solvers, hybrid BLAS, and energy efficiency for dense, as well as sparse, operations. Furthermore, as proposed, we investigated and experimented with various techniques targeting the five main areas outlined.

Dongarra, Jack J. [University Distinguished Professor; Tomov, Stanimire [Research Scientist

2014-03-24T23:59:59.000Z

173

Chamber transport of ''foot'' pulses for heavy-ion fusion  

SciTech Connect (OSTI)

Indirect-drive targets for heavy-ion fusion must initially be heated by ''foot'' pulses that precede the main heating pulses by tens of nanoseconds. These pulses typically have a lower energy and perveance than the main pulses, and the fusion-chamber environment is different from that seen by later pulses. The preliminary particle-in-cell simulations of foot pulses here examine the sensitivity of the beam focusing to ion-beam perveance, background-gas density, and pre-neutralization by a plasma near the chamber entry port.

Sharp, W.M.; Callahan-Miller, D.A.; Tabak, M.; Yu, S.S.; Peterson, P.F.

2002-02-20T23:59:59.000Z

174

Dissipative expansion chambers with two concentric layers of fibrous material  

Science Journals Connector (OSTI)

The acoustic performance of a dissipative expansion chamber lined with two concentric, annular layers of fibrous material with different resistances is investigated. A two-dimensional analytical approach is used to determine the transmission loss of this dissipative silencer. From the boundary conditions at the rigid wall, and the interfaces between the fibre layers and the central airway, the characteristic function and thus eigenvalues and eigenfunctions for sound propagation in the dissipative chamber are obtained, leading to transmission loss through application of pressure and velocity matching. The effects of geometry and fibre properties on the acoustic attenuation are also discussed.

A. Selamet; M.B. Xu; I.J. Lee; N.T. Huff

2005-01-01T23:59:59.000Z

175

E-Print Network 3.0 - axially loaded magnetic Sample Search Results  

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

magnetic Search Powered by Explorit Topic List Advanced Search Sample search results for: axially loaded magnetic Page: << < 1 2 3 4 5 > >> 1 Wireless Control of Magnetic Helical...

176

E-Print Network 3.0 - axial view inductively Sample Search Results  

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

and Rayleigh numbers close to onset of convection. Axial dipole solutions are subcritical in all Source: Aubert, Julien - Institut de Physique du Globe de Paris Collection:...

177

E-Print Network 3.0 - axial spondyloarthritis treated Sample...  

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

and Rayleigh numbers close to onset of convection. Axial dipole solutions are subcritical in all Source: Aubert, Julien - Institut de Physique du Globe de Paris Collection:...

178

E-Print Network 3.0 - axial iii-v heterostructure Sample Search...  

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

Letters 9, 3940 - 3944... of III-V semiconductor nanostructures and heterostructures Jordan Chesin 2nd-Year Graduate Student B... Nucleation & Growth Axial Heterostructure ......

179

E-Print Network 3.0 - axial loads Sample Search Results  

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

Steel Research 63 (2007) 165174 www.elsevier.comlocatejcsr Summary: -compacting concrete; Concrete-filled steel tube; Axial load behavior; Ultimate capacity; Confinement...

180

E-Print Network 3.0 - axial-flow hydraulic turbines Sample Search...  

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

Axial flow turbine are, instead, characterized by axis... Miller G., Corren D., Armstrong ... Source: Claps, Pierluigi - Dipartimento di Idraulica,Trasporti e Infrastrutture...

Note: This page contains sample records for the topic "axial magma chamber" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

E-Print Network 3.0 - axial stent strut Sample Search Results  

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

life prediction for cobalt-chromium stents Summary: condi- tions that would lead to strut fracture. 2. Material The stent in question was manufactured from... constrained axially...

182

E-Print Network 3.0 - axial mechanical properties Sample Search...  

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

in order to derive its structural rigidity for axial tension... response Reticulated tubes: effective elastic properties ... Source: Fleck, Norman A. - Mechanics, Materials and...

183

E-Print Network 3.0 - axially cracked pressure Sample Search...  

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

Collection: Engineering 2 MATERIAL POINT METHOD CALCULATIONS WITH EXPLICIT CRACKS, FRACTURE PARAMETERS, AND CRACK Summary: under axial impact with a crack in the central disk....

184

Numerical Modeling of Failure in Magnesium Alloys under Axial Compression and Bending for Crashworthiness Applications.  

E-Print Network [OSTI]

??Numerical modeling of failure was performed for magnesium alloys with circular and square cross-sections under axial compression. The failure criterion was employed using material model… (more)

Ali, Usman

2012-01-01T23:59:59.000Z

185

C3Bio.org - Resources: The Effect of Axial Ligand on the Oxidation...  

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

product yield and pKa of the axial ligand. The current work, using density functional calculations, examined geometric, electronic, and energetic parameters to determine if...

186

E-Print Network 3.0 - axially symmetric electron Sample Search...  

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

Mathematics 2 CASING EFFECTS ON THE RADIATION PERFORMANCE OF A CIRCULARLY POLARIZED PATCH ANTENNA Summary: . As an example, Fig. 2 shows the axial ratio when placed...

187

E-Print Network 3.0 - axially radiated power Sample Search Results  

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

Engineering 2 CASING EFFECTS ON THE RADIATION PERFORMANCE OF A CIRCULARLY POLARIZED PATCH ANTENNA Summary: on the radiation properties. Fig. 4 Gain (left) and axial ratio...

188

E-Print Network 3.0 - axial support motion Sample Search Results  

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

Medicine ; Engineering 7 Effect of boundary conditions on axial flow in a concentrated vortex core Richard K. Cohn and Manoochehr M. Koochesfahani Summary: oscil- lating...

189

E-Print Network 3.0 - axial em dente Sample Search Results  

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

Tel Aviv University Collection: Engineering ; Geosciences 5 On the ordering of energy levels in homogeneous magnetic fields Summary: field and in an axially symmetric...

190

E-Print Network 3.0 - axial volumetric 320-detector Sample Search...  

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

flow fan when the fan is operated on its high volumetric flow rate (low... -LEAKAGE VORTEX MINIMIZATION IN DUCTED AXIAL FANS USING NOVEL ... Source: Camci, Cengiz - Department...

191

A phenomenological multi-axial constitutive law for switching in polycrystalline ferroelectric ceramics  

E-Print Network [OSTI]

A phenomenological multi-axial constitutive law for switching in polycrystalline ferroelectric; accepted 30 January 2002 Abstract A phenomenological constitutive law for ferroelectric switching due

192

A cryogenic axial-centrifugal compressor for superfluid helium refrigeration  

E-Print Network [OSTI]

CERN's new project, the Large Hadron Collider (LHC), will use superfluid helium as coolant for its high-field superconducting magnets and therefore require large capacity refrigeration at 1.8 K. This may only be achieved by subatmospheric compression of gaseous helium at cryogenic temperature. To stimulate development of this technology, CERN has procured from industry prototype Cold Compressor Units (CCU). This unit is based on a cryogenic axial-centrifugal compressor, running on ceramic ball bearings and driven by a variable-frequency electrical motor operating under low-pressure helium at ambient temperature. The machine has been commissioned and is now in operation. After describing basic constructional features of the compressor, we report on measured performance.

Decker, L; Schustr, P; Vins, M; Brunovsky, I; Lebrun, P; Tavian, L

1997-01-01T23:59:59.000Z

193

Operational Experience with a Cryogenic Axial-Centrifugal Compressor  

E-Print Network [OSTI]

The Large Hadron Collider (LHC), presently under construction at CERN, requires large refrigeration capacity at 1.8 K. Compression of gaseous helium at cryogenic temperatures is therefore inevitable. Together with subcontractors, Linde Kryotechnik has developed a prototype machine. This unit is based on a cryogenic axial-centrifugal compressor, running on ceramic ball bearings and driven by a variable-frequency electrical motor operating at ambient temperature. Integrated in a test facility for superconducting magnets the machine has been commissioned without major problems and successfully gone through the acceptance test in autumn 1995. Subsequent steps were initiated to improve efficiency of this prototype. This paper describes operating experience gained so far and reports on measured performance prior to and after constructional modifications.

Decker, L; Löhlein, K; Purtschert, W; Ziegler, B L; Lebrun, P; Tavian, L; Brunovsky, I; Tucek, L

1998-01-01T23:59:59.000Z

194

Simple LMFBR axial-flow friction-factor correlation  

SciTech Connect (OSTI)

Complicated LMFBR axial lead-length averaged friction-factor correlations are reduced to an easy, ready-to-use function of bundle Reynolds number for wire-wrapped bundles. The function together with the power curves to calculate the associated constants are incorporated in a computer preprocessor, EZFRIC. The constants required for the calculation of the subchannels and bundle friction factors are derived and correlated into power curves of geometrical parameters. A computer program, FRIC, which can alternatively be used to accurately calculate these constants is also included. The accurate values of the constants and the corresponding values predicted by the power curves and percentage error of prediction are tabulated for a wide variety of geometries of interest.

Chan, Y.N.; Todreas, N.E.

1982-12-01T23:59:59.000Z

195

Hamilton's equations for a fluid membrane: axial symmetry  

E-Print Network [OSTI]

Consider a homogenous fluid membrane, or vesicle, described by the Helfrich-Canham energy, quadratic in the mean curvature. When the membrane is axially symmetric, this energy can be viewed as an `action' describing the motion of a particle; the contours of equilibrium geometries are identified with particle trajectories. A novel Hamiltonian formulation of the problem is presented which exhibits the following two features: {\\it (i)} the second derivatives appearing in the action through the mean curvature are accommodated in a natural phase space; {\\it (ii)} the intrinsic freedom associated with the choice of evolution parameter along the contour is preserved. As a result, the phase space involves momenta conjugate not only to the particle position but also to its velocity, and there are constraints on the phase space variables. This formulation provides the groundwork for a field theoretical generalization to arbitrary configurations, with the particle replaced by a loop in space.

Riccardo Capovilla; Jemal Guven; Efrain Rojas

2005-05-25T23:59:59.000Z

196

www.ornl.gov Environmental Chambers at ORNL  

E-Print Network [OSTI]

-air HVAC system, heat pump water heaters, a dehumidifying water heater, solid-state lighting, hybrid solar-by-side chambers can test gas heat pumps, electric heat pumps and air conditioners, gas/electric packaged units, desiccant systems, and small distributed generation/combined heat and power (CHP) systems with capacities

Oak Ridge National Laboratory

197

Micromegas chambers for the ATLAS Muon Spectrometer Upgrade  

E-Print Network [OSTI]

Micromegas (Micro MEsh Gaseous Structure) chambers have been proven along the years to be reliable fast detectors with an excellent spatial resolution. The ATLAS collaboration at LHC has chosen the micromegas technology along with the small-strip Thin Gap Chambers (sTGC) for the high luminosity upgrade of the inner muon station in the high-rapidity region, the so called New Small Wheel (NSW). It employs eight layers of micromegas detectors and eight layers of sTGC. The NSW project requires fully efficient micromegas chambers with spatial resolution down to $100\\mu m$ over a total active area of $1200 m^2$ with a rate capability up to $10 kHz/cm^2$ and operation in a moderate magnetic field up to B=0.3 T. The required tracking capability is provided by the intrinsic space resolution combined with a mechanical precision at the level of $30 \\mu m$ along the precision coordinate. Moreover together with the precise tracking capability the micromegas chambers should provide a trigger signal. An extensive R&D pr...

Ntekas, Konstantinos; The ATLAS collaboration

2014-01-01T23:59:59.000Z

198

Hydrogen Production in a Single Chamber Microbial Electrolysis Cell  

E-Print Network [OSTI]

) at greater yields than fermentation and at greater energy efficiencies than water electrolysis. It has been to produce water. A microbial electrolysis cell (MEC) operates in a manner similar to an MFC exceptHydrogen Production in a Single Chamber Microbial Electrolysis Cell Lacking a Membrane D O U G L

199

Harvesting Energy from Wastewater in a 2-Chamber  

E-Print Network [OSTI]

Harvesting Energy from Wastewater in a 2-Chamber Microbial Fuel Cell Sikandar Present day wastewater treatment plants utilize high amounts of energy and are costly to operate. These conventional wastewater treatment plants utilize aerobic bacteria. Organic material in wastewater contains energy that can

200

A Moore-Greitzer axial compressor model with spool Jan Tommy Gravdahl and Olav Egeland  

E-Print Network [OSTI]

/surge-model. A model for centrifugal compressors with nonconstant speed was presented in 2]. In 5] a similar model applies to centrifugal compressors. It seems that the modeling and control of an axial com- pression) Table 1: Development in compressor stall/surge- control. A=Axial, C=Centrifugal, M=Modeling, C

Gravdahl, Jan Tommy

Note: This page contains sample records for the topic "axial magma chamber" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Measurements of Film Flow Rate in Heated Tubes with Various Axial Power Distributions  

E-Print Network [OSTI]

Measurements of Film Flow Rate in Heated Tubes with Various Axial Power Distributions by Carl, Measurements of Film Flow Rate in Heated Tubes with Various Axial Power Distributions KTH Nuclear Reactor power is limited by a phenomenon called critical heat flux (CHF). It appears as a sudden detoriation

Haviland, David

202

1 Mayne & Schneider EVALUATING AXIAL DRILLED SHAFT RESPONSE BY SEISMIC CONE  

E-Print Network [OSTI]

1 Mayne & Schneider EVALUATING AXIAL DRILLED SHAFT RESPONSE BY SEISMIC CONE Paul W. Mayne1 , M using the results of seismic piezocone penetration tests (SCPTU) to provide continuous profiles of small to discuss the use of seismic piezocone testing for the evaluation of both axial capacity (obtained from

Mayne, Paul W.

203

Dispersion relation and growth rate in a Cherenkov free electron laser: Finite axial magnetic field  

SciTech Connect (OSTI)

A theoretical analysis is presented for dispersion relation and growth rate in a Cherenkov free electron laser with finite axial magnetic field. It is shown that the growth rate and the resonance frequency of Cherenkov free electron laser increase with increasing axial magnetic field for low axial magnetic fields, while for high axial magnetic fields, they go to a saturation value. The growth rate and resonance frequency saturation values are exactly the same as those for infinite axial magnetic field approximation. The effects of electron beam self-fields on growth rate are investigated, and it is shown that the growth rate decreases in the presence of self-fields. It is found that there is an optimum value for electron beam density and Lorentz relativistic factor at which the maximum growth rate can take place. Also, the effects of velocity spread of electron beam are studied and it is found that the growth rate decreases due to the electron velocity spread.

Kheiri, Golshad; Esmaeilzadeh, Mahdi [Department of Physics, Iran University of Science and Technology, Tehran 16844 (Iran, Islamic Republic of)] [Department of Physics, Iran University of Science and Technology, Tehran 16844 (Iran, Islamic Republic of)

2013-12-15T23:59:59.000Z

204

Development and test of combustion chamber for Stirling engine heated by natural gas  

Science Journals Connector (OSTI)

The combustion chamber is an important component for the Stirling engine heated by natural gas. In the paper ... , we develop a combustion chamber for the Stirling engine which aims to generate 3?5 kWe...electric...

Tie Li; Xiange Song; Xiaohong Gui; Dawei Tang; Zhigang Li…

2014-04-01T23:59:59.000Z

205

-The Bubble Chamber -http://thebubblechamber.org -Review: Cold War Social Science  

E-Print Network [OSTI]

[1] - The Bubble Chamber - http://thebubblechamber.org - Review: Cold War Social Science Posted assume that all developments in the social sciences during the Cold War period can be The Bubble Chamber

Solovey, Mark

206

Beam Loss Ion Chamber System Upgrade for Experimental Halls  

SciTech Connect (OSTI)

The Beam loss Ion Chamber System (BLICS) was developed to protect Jefferson Labs transport lines, targets and beam dumps from a catastrophic ''burn through''. Range changes and testing was accomplished manually requiring the experiment to be shut down. The new upgraded system is based around an ''off the shelf'' Programmable Logic Controller located in a single control box supporting up to ten individual detectors. All functions that formerly required an entry into the experimental hall and manual adjustment can be accomplished from the Machine Control Center (MCC). A further innovation was the addition of a High Voltage ''Brick'' at the detector location. A single cable supplies the required voltage for the Brick and a return line for the ion chamber signal. The read back screens display range, trip point, and accumulated dose for each location. The new system is very cost effective and significantly reduces the amount of lost experimental time.

D.W. Dotson; D.J. Seidman

2005-05-16T23:59:59.000Z

207

Development and characterization of a chamber gram estimator  

SciTech Connect (OSTI)

The Chamber Gram Estimator (CGE), Model SAM-1B is a small article gamma monitor originally designed to screen items for radioactive contamination that may be placed into its chamber. Four plastic scintillator detectors detect photons emitted from bulk quantities of fissile materials in line generated waste and provide a fissile mass content estimate of waste packages. With the present CGE, a few grams of {sup 239}Pu could be distinguished above background in light matrix samples. It is controlled by a personal computer that uses a menu driven operating program. The program is designed to reduce the potential for operator error while obtaining a fissile material gram estimate of a line generated waste package prior to placement in a drum. This report describes the work performed to characterize the counting chamber for fissile material estimation. The operating features of the CGE, the results and conclusions drawn from the experiments, and the future work recommended for the next generation CGEs are also described. The CGE provides advantages over hand-held Ludlum 12-12 survey-type instruments presently in use. The CGE is easy to operate, does not require manual manipulation to measure the total surf ace of the sample, and provides a display free of rate meter response-time effects or the need for visual averaging. Moreover, the response variations due to sample geometry are significantly less than with a hand-held arrangement, particularly, for the low density matrix samples appropriate for estimation. The waste packages are placed inside the instrument`s shielded chamber which effectively eliminates gamma exposure to operators from waste packages.

Dulco, G.B.; Gupta, V.P.; Balmer, D.K.

1995-07-01T23:59:59.000Z

208

Using sputter coated glass to stabilize microstrip gas chambers  

DOE Patents [OSTI]

By sputter coating a thin-layer of low-resistive, electronically-conductive glass on various substrates (including quartz and ceramics, thin-film Pestov glass), microstrip gas chambers (MSGC) of high gain stability, low leakage current, and a high rate capability can be fabricated. This design can make the choice of substrate less important, save the cost of ion-implantation, and use less glass material.

Gong, Wen G. (Albany, CA)

1997-01-01T23:59:59.000Z

209

CLOUD CHAMBER: A PERFORMANCE INVOLVING REAL TIME TWO-WAY INTERACTION BETWEEN SUBATOMIC RADIOACTIVE  

E-Print Network [OSTI]

will be placed in the chamber on stage, saturated with ethanol and cooled by liquid nitrogen, which makes

Miranda, Eduardo Reck

210

Cavity resonances in engine combustion chambers and some applications  

Science Journals Connector (OSTI)

Cavity resonances in engine cylinders are caused by combustion events such as the rapid rate of pressure rise that occurs during compression ignition in diesels or from knock in gasoline engines. These resonances generally occur at frequencies greater than 4 to 5 kHz where the engine structure is not an efficient acoustical radiator. However when they occur at lower frequencies such as in engines with a large bore or in indirect injection diesels they can be important in the noise generation process. They are also important for knock detection in gasoline engines. Current knock detection systems are tuned to the frequency band of the lowest cavity resonance in the combustion chamber. It is shown in the paper that higher order resonances can also be detected by a knock vibration sensor on the surface of the engine. Another use for the cavity resonances is to determine the bulk temperature of the gas in the combustion chamber as a function of crank angle. This technique is demonstrated in the paper for a heavy?duty two?stroke diesel. Also the results of several fundamental investigations of cavity resonances in engine combustion chambers are reported briefly. Good agreement is obtained between theoretical prediction of the resonant frequencies and experimental observation. The splitting of degenerate modes into two components is discussed.

Robert Hickling; Douglas A. Feldmaier; Francis H. K. Chen; Josette S. Morel

1983-01-01T23:59:59.000Z

211

LAYOUT AND SIZING OF ESF ALCOVES AND REFUGE CHAMBERS  

SciTech Connect (OSTI)

The purpose of this analysis is to establish size requirements and approximate locations of Exploratory Studies Facility (ESF) test and operations alcoves, including refuge chambers during construction of the Topopah Spring (TS) loop. Preliminary conceptual layouts for non-deferred test alcoves will be developed to examine construction feasibility based on current test plans and available equipment. The final location and configuration layout for alcoves will be developed when in-situ rock conditions can be visually determined. This will be after the TBM has excavated beyond the alcove location and the rock has been exposed. The analysis will examine the need for construction of walkways and electrical alcoves in the ramps and main drift. Niches that may be required to accommodate conveyor booster drives and alignments are not included in this analysis. The analysis will develop design criteria for refuge chambers to meet MSHA requirements and will examine the strategic location of refuge chambers based on their potential use in various ESF fire scenarios. This document supersedes DI:BABE00000-01717-0200-00003 Rev 01, ''TS North Ramp Alcove and Stubout Location Analysis'' in its entirety (Reference 5-6).

John Beesley and Romeo S. Jurani

1995-08-25T23:59:59.000Z

212

Multistage axial-flux PM machine for wheel direct drive  

SciTech Connect (OSTI)

The design of direct-drive wheel motors must comply with diameter restriction due to housing the motor in a wheel rim and allow the achievement of very high torque density and overload capability. Slotless axial-flux permanent magnet machines (AFPMs) prove to be the best candidate for application in electric vehicles as direct-drive wheel motors, as in comparison with conventional machines they allow designs with higher compactness, lightness and efficiency. The paper presents a newly conceived AFPM which has a multistage structure and a water-cooled ironless stator. In the proposed new topology of the machine the space formerly occupied by the toroidal core becomes a water duct, which removes heat directly from the interior surface of the stator winding. The high efficiency of the machine cooling arrangement allows long-term 100% overload operation and great reduction of the machine weight. The multistage structure of the machine is suited to overcome the restriction on the machine diameter and meet the torque required at the wheel shaft. The paper gives guidelines for the design of a multistage AFPM with water-cooled ironless stator, and describes characteristics of a two-stage prototype machine rated 215 N{center_dot}m, 1,100 r/min.

Caricchi, F.; Crescimbini, F.; Mezzetti, F.; Santini, E. [Univ. of Rome La Sapienza (Italy). Dept. of Electrical Engineering] [Univ. of Rome La Sapienza (Italy). Dept. of Electrical Engineering

1996-07-01T23:59:59.000Z

213

Negative particle planar and axial channeling and channeling collimation  

SciTech Connect (OSTI)

While information exists on high energy negative particle channeling there has been little study of the challenges of negative particle bending and channeling collimation. Partly this is because negative dechanneling lengths are relatively much shorter. Electrons are not particularly useful for investigating negative particle channeling effects because their material interactions are dominated by channeling radiation. Another important factor is that the current central challenge in channeling collimation is the proton-proton Large Hadron Collider (LHC) where both beams are positive. On the other hand in the future the collimation question might reemerge for electon-positron or muon colliders. Dechanneling lengths increase at higher energies so that part of the negative particle experimental challenge diminishes. In the article different approaches to determining negative dechanneling lengths are reviewed. The more complicated case for axial channeling is also discussed. Muon channeling as a tool to investigate dechanneling is also discussed. While it is now possible to study muon channeling it will probably not illuminate the study of negative dechanneling.

Carrigan, Richard A., Jr.; /Fermilab

2009-12-01T23:59:59.000Z

214

Light-scattering properties of plate and column ice crystals generated in a laboratory cold chamber  

E-Print Network [OSTI]

with a diode laser beam. This cloud chamber produces distinct plate and hollow column ice crystal types. The cloud chamber developed at the Desert Re- search Institute has been used to produce ice clouds composedLight-scattering properties of plate and column ice crystals generated in a laboratory cold chamber

Liou, K. N.

215

Development of bubble chambers with sensitivity to WIMPs , J. I. Collarb*  

E-Print Network [OSTI]

of high- stability bubble chambers containing heavy liquids as an alternative to SDDs. The use of a stableDevelopment of bubble chambers with sensitivity to WIMPs L. Bonda , J. I. Collarb* , J. Elya , M@uchicago.edu We constructed a small bubble chamber, with special features needed to search for WIMPs: long

Collar, Juan I.

216

Los Alamos honored by Española Valley Chamber of Commerce  

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

LANL Honored By Española Valley Chamber of Commerce LANL Honored By Española Valley Chamber of Commerce Community Connections: Our link to Northern New Mexico Communities Latest Issue:Dec. 2013 - Jan. 2014 All Issues » submit Los Alamos honored by Española Valley Chamber of Commerce The Espanola Valley Chamber of Commerce recognized the Lab for its support to the chamber and the entire Espanola Valley with a President's Choice Award. February 1, 2013 dummy image Read our archives. Contacts Editor Linda Anderman Email Community Programs Office Kurt Steinhaus Email The Lab received the award for efforts in a variety of areas. In late January, the Espanola Valley Chamber of Commerce recognized the Lab for its support to the chamber and the entire Espanola Valley with a President's Choice Award. Kurt Steinhaus with the Lab's Community

217

Performance parameters of a liquid filled ionization chamber array  

SciTech Connect (OSTI)

Purpose: In this work, the properties of the two-dimensional liquid filled ionization chamber array Octavius 1000SRS (PTW-Freiburg, Germany) for use in clinical photon-beam dosimetry are investigated.Methods: Measurements were carried out at an Elekta Synergy and Siemens Primus accelerator. For measurements of stability, linearity, and saturation effects of the 1000SRS array a Semiflex 31013 ionization chamber (PTW-Freiburg, Germany) was used as a reference. The effective point of measurement was determined by TPR measurements of the array in comparison with a Roos chamber (type 31004, PTW-Freiburg, Germany). The response of the array with varying field size and depth of measurement was evaluated using a Semiflex 31010 ionization chamber as a reference. Output factor measurements were carried out with a Semiflex 31010 ionization chamber, a diode (type 60012, PTW-Freiburg, Germany), and the detector array under investigation. The dose response function for a single detector of the array was determined by measuring 1 cm wide slit-beam dose profiles and comparing them against diode-measured profiles. Theoretical aspects of the low pass properties and of the sampling frequency of the detector array were evaluated. Dose profiles measured with the array and the diode detector were compared, and an intensity modulated radiation therapy (IMRT) field was verified using the Gamma-Index method and the visualization of line dose profiles.Results: The array showed a short and long term stability better than 0.1% and 0.2%, respectively. Fluctuations in linearity were found to be within ±0.2% for the vendor specified dose range. Saturation effects were found to be similar to those reported in other studies for liquid-filled ionization chambers. The detector's relative response varied with field size and depth of measurement, showing a small energy dependence accounting for maximum signal deviations of ±2.6% from the reference condition for the setup used. The ?-values of the Gaussian dose response function for a single detector of the array were found to be (0.72 ± 0.25) mm at 6 MV and (0.74 ± 0.25) mm at 15 MV and the corresponding low pass cutoff frequencies are 0.22 and 0.21 mm{sup ?1}, respectively. For the inner 5 × 5 cm{sup 2} region and the outer 11 × 11 cm{sup 2} region of the array the Nyquist theorem is fulfilled for maximum sampling frequencies of 0.2 and 0.1 mm{sup ?1}, respectively. An IMRT field verification with a Gamma-Index analysis yielded a passing rate of 95.2% for a 3 mm/3% criterion with a TPS calculation as reference.Conclusions: This study shows the applicability of the Octavius 1000SRS in modern dosimetry. Output factor and dose profile measurements illustrated the applicability of the array in small field and stereotactic dosimetry. The high spatial resolution ensures adequate measurements of dose profiles in regular and intensity modulated photon-beam fields.

Poppe, B.; Stelljes, T. S.; Looe, H. K.; Chofor, N. [Clinic for Radiation Therapy, Pius-Hospital, Oldenburg 26121, Germany and WG Medical Radiation Physics, Carl von Ossietzky University, Oldenburg 26121 (Germany)] [Clinic for Radiation Therapy, Pius-Hospital, Oldenburg 26121, Germany and WG Medical Radiation Physics, Carl von Ossietzky University, Oldenburg 26121 (Germany); Harder, D. [Prof. em., Medical Physics and Biophysics, Georg August University, Göttingen 37073 (Germany)] [Prof. em., Medical Physics and Biophysics, Georg August University, Göttingen 37073 (Germany); Willborn, K. [Clinic for Radiation Therapy, Pius-Hospital, Oldenburg 26121 (Germany)] [Clinic for Radiation Therapy, Pius-Hospital, Oldenburg 26121 (Germany)

2013-08-15T23:59:59.000Z

218

Statistics of the electromagnetic response of a chaotic reverberation chamber  

E-Print Network [OSTI]

This article presents a study of the electromagnetic response of a chaotic reverberation chamber (RC) in the presence of losses. By means of simulations and of experiments, the fluctuations in the maxima of the field obtained in a conventional mode-stirred RC are compared with those in a chaotic RC in the neighborhood of the Lowest Useable Frequency (LUF). The present work illustrates that the universal spectral and spatial statistical properties of chaotic RCs allow to meet more adequately the criteria required by the Standard IEC 61000-4-21 to perform tests of electromagnetic compatibility.

J. -B. Gros; U. Kuhl; O. Legrand; F. Mortessagne; O. Picon; E. Richalot

2014-09-20T23:59:59.000Z

219

E-Print Network 3.0 - axial free-electron laser Sample Search...  

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

free-electron laser Search Powered by Explorit Topic List Advanced Search Sample search results for: axial free-electron laser Page: << < 1 2 3 4 5 > >> 1 JOURNAL DE PHYSIQUE...

220

Hydrodynamic Model with Binary Particle Diameters to Predict Axial Voidage Profile in a CFB Combustor  

Science Journals Connector (OSTI)

A hydrodynamic model with binary particle diameters was developed to better predict axial voidage profile in a CFB combustor. In the model, the CFB is regarded as a superposition of two ... field data of voidage ...

J. J. Li; H. Zhang; H. R. Yang; Y. X. Wu…

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "axial magma chamber" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Radial characterisation of the helium plasma produced by the axial injection torch (TIA) at atmospheric pressure  

Science Journals Connector (OSTI)

This work presents the radial characterisation of a helium plasma produced by the “Torch ŕ Injection Axiale ... using a collisional-radiative model for helium at atmospheric pressure, the electronic density and e...

R. Álvarez; A. Rodero; M. C. Quintero

2000-03-01T23:59:59.000Z

222

Correction to the Chiral Magnetic Effect from axial-vector interaction  

E-Print Network [OSTI]

The recent lattice calculation at finite axial chemical potential suggests that the induced current density of the chiral magnetic effect (CME) is somehow suppressed comparing with the standard analytical formula. We show in a NJL-type model of QCD that such a suppression is a natural result when considering the influence of the attractive axial-vector interaction. We point out that the lattice result doesn't need to be quantitatively consistent with the analytical formula due to the chirality density-density correlation. We also investigate the nonperturbative effect of instanton molecules on the CME. Since an unconventional repulsive axial-vector interaction is induced, the CME will be enhanced significantly by the instanton-anti-instanton pairings. Such a prediction needs to be tested by more improved lattice simulations. We further demonstrate that the axial-vector interaction plays an important role on the $T-\\mu_A$ phase diagram.

Zhao Zhang

2012-01-02T23:59:59.000Z

223

A simple criterion for three-dimensional flow separation in axial compressors  

E-Print Network [OSTI]

Most modem blade designs in axial-flow compressors diffuse the flow efficiently over 20% to 80% of blade span and it is the endwall regions that set the limits in compressor performance. This thesis addresses the estimation, ...

Lei, Vai-Man

2006-01-01T23:59:59.000Z

224

E-Print Network 3.0 - axial seamount harbor Sample Search Results  

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

present in the axial zone of the GSC has been determined using high... likelihood model Smith and Cann, 1992. The number of ... Source: Graham, David W. - College of Oceanic and...

225

E-Print Network 3.0 - axial skeletal manifestations Sample Search...  

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

for: axial skeletal manifestations Page: << < 1 2 3 4 5 > >> 1 insight review articles NATURE | VOL 423 | 15 MAY 2003 | www.nature.comnature 343 Summary: develop- mental pathways....

226

E-Print Network 3.0 - axially deformed transition Sample Search...  

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

stainless steel subjected to in situ biaxial loading Summary: the loading sequence in the elastic-plastic transition (case r hh r zz 0:7). (b) Axial and hoop lattice... a...

227

Application of Regge Calculus to the Axially Symmetric Initial-Value Problem in General Relativity  

Science Journals Connector (OSTI)

Using Regge calculus some axially symmetric solutions of the initial-value equations of general relativity are constructed at the moment of time symmetry. Examples of infinite and closed spaces are given.

P. A. Collins and Ruth M. Williams

1972-04-15T23:59:59.000Z

228

E-Print Network 3.0 - axial heat conduction Sample Search Results  

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

2006 by ASME Proceedings of ASME TURBO EXPO 2007 Summary: and with lateral conduction loss) Figure 11 Heat transfer coefficient h at five axial locations on the casing plate......

229

E-Print Network 3.0 - axial ratio Sample Search Results  

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

Engineering 2 CASING EFFECTS ON THE RADIATION PERFORMANCE OF A CIRCULARLY POLARIZED PATCH ANTENNA Summary: -7803-8302-80420.00 2004 IEEE 12;Fig.1b Axial ratio and gain...

230

Bounds for axially symmetric linear perturbations for the extreme Kerr black hole  

E-Print Network [OSTI]

We obtain remarkably simple integral bounds for axially symmetric linear perturbations for the extreme Kerr black hole in terms of conserved energies. From these estimates we deduce pointwise bounds for the perturbations outside the horizon.

Dain, Sergio

2015-01-01T23:59:59.000Z

231

Hadley Circulations in Radiative–Convective Equilibrium in an Axially Symmetric Atmosphere  

Science Journals Connector (OSTI)

Hadley circulations in radiative–convective equilibrium are investigated using an idealistic axially symmetric model. Calculations show that the distribution of temperature in the Hadley cell is controlled by the moist process; the vertical ...

Masaki Satoh

1994-07-01T23:59:59.000Z

232

E-Print Network 3.0 - axial power distribution Sample Search...  

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

and cyclotron mode in the precision trap. The measurement yields the ion's axial energy distribution... of the trapping potential is to measure the depth of the dip in the...

233

Design and PHILS-based Transient Analysis of a Tri-axial HTS Power Cable  

Science Journals Connector (OSTI)

Abstract Tri-axial high-temperature superconducting (HTS) power cables are very efficient compared with other HTS power cables due to their reduced use of HTS wires and cryogenic surface area, resulting from the mutually layered structure of the three phases. However, the operating characteristics of tri-axial HTS power cables differ from other cables in a transient-state condition. In order to install HTS power cables in a real grid, feasibility verification through simulation or experimentation is required in advance. Thus, the authors design a tri-axial HTS power cable and implement a power hardware-in-the-loop simulation that consists of a real time digital simulator-based simulation model and hardware devices including a power supply and a 1 m-long tri-axial HTS model cable. Simulation results show the stability verification under steady-state and transient-state conditions.

Sun-Kyoung Ha; Chang-Soon Kim; Sung-Kyu Kim; Minh-Chau Dinh; Jin-Geun Kim; Minwon Park; In-Keun Yu; Sangjin Lee; Kideok Sim

2014-01-01T23:59:59.000Z

234

Determination of the ?(1232) axial and pseudoscalar form factors from lattice QCD  

E-Print Network [OSTI]

We present a lattice QCD calculation of the ?(1232) matrix elements of the axial-vector and pseudoscalar currents. The decomposition of these matrix elements into the appropriate Lorentz invariant form factors is carried ...

Alexandrou, Constantia

235

Vermont Yankee's benefits and concerns operating with Axially zoned GE9 fuel  

SciTech Connect (OSTI)

Vermont Yankee (VY) is a 368-assembly, D-lattice, boiling water reactor (BWR)/4. The current cycle 16 contains 252 GE9 assemblies with axial zoning of gadolinium and enrichment, 112 GE8 assemblies with axially zoned gadolinium, and 4 Siemens 9 x 9-IX lead qualification assemblies. In this paper, the performance of the GE9-dominated core is evaluated against previous cores containing less sophisticated fuel designs.

Woehlke, R.A. (Yankee Atomic Electric Co., Bolton, MA (United States))

1993-01-01T23:59:59.000Z

236

Experiments and analysis for an axially heterogeneous LMR assembly at ZPPR  

SciTech Connect (OSTI)

Experiments in ZPPR-17 provided physics data for a full-scale (700 MWe) axially heterogeneous LMR. Measurements and analysis are reported for control rod worths, reaction rate distributions, gamma dose distribution, sodium void worths and criticality. Agreement between measurement and calculation are generally satisfactory, but the axial heterogeneity did introduce analytical complications. Some calculational methods gave less good agreement with measurements than in previous homogeneous or radially heterogeneous assemblies. 10 refs., 7 figs., 6 tabs.

Collins, P.J.; Brumbach, S. B.

1988-01-01T23:59:59.000Z

237

Photon statistics in a free-electron laser with an axial-guide magnetic field  

Science Journals Connector (OSTI)

Starting from an initial state with an electron energy p02/2m+??c/2, a vacuum-laser field, and a coherent wiggler field, I discuss photon statistics in a free-electron laser with an axial-guide magnetic field. It is found that the axial field can weaken the squeezing, enhance the positive (for ?>0) and negative (for ?0) and antibunching (for ?<0).

Gou San-kui

1992-07-15T23:59:59.000Z

238

Interaction diagrams for CHS T-DT multiplanar joints under axial loads  

SciTech Connect (OSTI)

The paper describes a finite element study of the elastic and plastic behavior of multiplanar T-DT welded joints in circular members, under three dimensional axial loading. Weld modeling is considered and interaction diagrams for strength derived for branch width ratios of 0.25 and 0.6. Comparisons are made with design recommendations. The increase in strength observed for DT-DT joints for the same sense axial loading does not occur for T-DT joints.

Davies, G.; Crockett, P. [Univ. of Nottingham (United Kingdom)

1994-12-31T23:59:59.000Z

239

The backflow cell model of steady state flow reactors with axial dispersion  

E-Print Network [OSTI]

THE BACKFLOW CELL MODEL OF STEADY STATE FLOW REACTORS WITH AXIAL DISPERSION A Thesis By John Thomas Baldwin Submitted to the Graduate College of the Texas A/M University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE May 1966 Major Subject;. Chemical Engineering THE BACKFLOW CELL MODEL OF STEADY STATE FLOW REACTORS WITH AXIAL DISPERSION A Thesis By John Thomas Baldwin Approved as to style and content by: C airman o ommittee ea o epartment (Member...

Baldwin, John Thomas

2012-06-07T23:59:59.000Z

240

Beam quality conversion factors for parallel-plate ionization chambers in MV photon beams  

SciTech Connect (OSTI)

Purpose: To investigate the behavior of plane-parallel ion chambers in high-energy photon beams through measurements and Monte Carlo simulations. Methods: Ten plane-parallel ion chamber types were obtained from the major ion chamber manufacturers. Absorbed dose-to-water calibration coefficients are measured for these chambers and k{sub Q} factors are determined. In the process, the behaviors of the chambers are characterized through measurements of leakage currents, chamber settling in cobalt-60, polarity and ion recombination behavior, and long-term stability. Monte Carlo calculations of the absorbed dose to the air in the ion chamber and absorbed dose to water are obtained to calculate k{sub Q} factors. Systematic uncertainties in Monte Carlo calculated k{sub Q} factors are investigated by varying material properties and chamber dimensions. Results: Chamber behavior was variable in MV photon beams, especially with regard to chamber leakage and ion recombination. The plane-parallel chambers did not perform as well as cylindrical chambers. Significant differences up to 1.5% were observed in calibration coefficients after a period of eight months although k{sub Q} factors were consistent on average within 0.17%. Chamber-to-chamber variations in k{sub Q} factors for chambers of the same type were at the 0.2% level. Systematic uncertainties in Monte Carlo calculated k{sub Q} factors ranged between 0.34% and 0.50% depending on the chamber type. Average percent differences between measured and calculated k{sub Q} factors were - 0.02%, 0.18%, and - 0.16% for 6, 10, and 25 MV beams, respectively. Conclusions: Excellent agreement is observed on average at the 0.2% level between measured and Monte Carlo calculated k{sub Q} factors. Measurements indicate that the behavior of these chambers is not adequate for their use for reference dosimetry of high-energy photon beams without a more extensive QA program than currently used for cylindrical reference-class ion chambers.

Muir, B. R.; McEwen, M. R.; Rogers, D. W. O. [Carleton Laboratory for Radiotherapy Physics, Physics Department, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6 (Canada); Institute for National Measurement Standards, National Research Council of Canada, Ottawa, Ontario K1A 0R6 (Canada); Carleton Laboratory for Radiotherapy Physics, Physics Department, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6 (Canada)

2012-03-15T23:59:59.000Z

Note: This page contains sample records for the topic "axial magma chamber" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Slag monitoring system for combustion chambers of steam boilers  

SciTech Connect (OSTI)

The computer-based boiler performance system presented in this article has been developed to provide a direct and quantitative assessment of furnace and convective surface cleanliness. Temperature, pressure, and flow measurements and gas analysis data are used to perform heat transfer analysis in the boiler furnace and evaporator. Power boiler efficiency is calculated using an indirect method. The on-line calculation of the exit flue gas temperature in a combustion chamber allows for an on-line heat flow rate determination, which is transferred to the boiler evaporator. Based on the energy balance for the boiler evaporator, the superheated steam mass flow rate is calculated taking into the account water flow rate in attemperators. Comparing the calculated and the measured superheated steam mass flow rate, the effectiveness of the combustion chamber water walls is determined in an on-line mode. Soot-blower sequencing can be optimized based on actual cleaning requirements rather than on fixed time cycles contributing to lowering of the medium usage in soot blowers and increasing of the water-wall lifetime.

Taler, J.; Taler, D. [Cracow University of Technology, Krakow (Poland)

2009-07-01T23:59:59.000Z

242

Heat transfer and pollutant formation mechanisms in insulated combustion chambers  

SciTech Connect (OSTI)

The authors have studied the quenching situation as it can be found in constant volume combustion chambers for a methane flame over a range of wall temperatures between 300 K and 600 K using Direct Numerical Simulation. To do this, the authors solved the fully compressible, one-dimensional Navier-Stokes equations with detailed mechanisms for kinetics and diffusion. This approach allows to compare various reaction schemes, to identify the most important species and reaction paths, and to investigate the influence of different modeling assumptions. The computational results show that the dimensional wall heat flux increases with wall temperature over the whole range of wall temperatures studied; this agrees well with the most recent measurements in a strongly improved experimental setup. It is found that the wall can be modeled as chemically inert and thermal diffusion processes are negligible for low wall temperatures between 300 K and 400 K. However, at higher temperatures, due to a dramatically increasing radical concentration (H, Oh, OH) at the wall, both become increasingly important leading to large heat release rates directly at the metallic wall surface of the combustion chamber, and can thus not be neglected in the modeling of the quenching process. Furthermore, these high radical concentrations adjacent to the wall indicate that the uncertainties in wall heat flux measurements at high wall temperatures could be underestimated by the experimentalists. The UHC concentration at a wall temperature of 600 K is about 20 times smaller than for 300 K after quenching. 37 refs., 12 figs., 1 tab.

Popp, P.; Baum, M.

1995-12-31T23:59:59.000Z

243

Development of linseed oil-free bakelite resistive plate chambers  

E-Print Network [OSTI]

In this paper we would like to present a few characteristics of the Resistive Plate Chambers (RPC) made of a particular grade of bakelite paper laminates (P-120, NEMA LI-1989 Grade XXX), produced and commercially available in India. This particular grade is used for high voltage insulation in humid conditions. The chambers are tested with cosmic rays in the streamer mode using argon, tetrafluroethane and isobutane in 34:59:7 mixing ratio. In the first set of detectors made with such grade, a thin coating of silicone fluid on the inner surfaces of the bakelite was found to be necessary for operation of the detector. Those silicone coated RPCs were found to give satisfactory performance with stable efficiency of >90% continuously for a long period as reported earlier. Results of the crosstalk measurement of these silicone coated RPC will be presented in this paper. Very recently RPCs made with the same grade of bakelite but having better surface finish, are found to give equivalent performance even without any ...

Biswas, S; Bose, S; Chattopadhyay, S; Saha, S; Viyogi, Y P

2009-01-01T23:59:59.000Z

244

Nuclear Instruments and Methods in Physics Research A 469 (2001) 4754 The HERMES forward tracking chambers: construction,  

E-Print Network [OSTI]

, which use an Ar=CF4=CO2 (90 : 5 : 5) gas mixture. No degradation in chamber performance has been. PACS: 29.40.Cs; 07.89.+b Keywords: Wire chamber; CF4 gas; Aging studies; Radiation damage; HERMES rate operation of chambers with gas mixtures containing CF4. 2. Mechanical design Each chamber consists

245

3.0 GROWTH FACILITY SPACE REQUESTS Prospective users of the greenhouses or growth chambers are encouraged to  

E-Print Network [OSTI]

for greenhouse and growth chamber specifications, including space, lighting and fees. Greenhouse and Growth Chamber Space Inventory Greenhouse and Growth Chamber Lighting Inventory #12;Hourly Rate Service Charges3.0 GROWTH FACILITY SPACE REQUESTS Prospective users of the greenhouses or growth chambers

Pawlowski, Wojtek

246

Development of a multistep parallel-plate chamber as time projection chamber end-cap or vertex detector  

SciTech Connect (OSTI)

In the course of development of the multistep avalanche chamber the authors have realized several multiple electrode parallel-plate devices exhibiting stable gains well in excess of 10/sup 5/ which are thus capable of detecting minimum ionizing particles. This paper presents the design and discusses the performance of a two-step parallel-plate avalanche chamber. A region of moderate electric field --the drift region where charges are released by ionizing radiation--is followed by two layers of comparable and very high field where charge multiplication occurs. Owing to the choice of the electrodes--either cross-wire meshes or parallel thick-wire grids at small pitch--the electric field is uniform over most of the gaps, and charge multiplication proceeds through a parallel-plate avalanche mode. In order to obtain a fast signal and a reduced avalanche spread in their prototypes, the authors have adopted rather narrow typical gaps of 4 mm for the first amplification region and 1 mm for the second. To avoid edge sparking, they have used either a gap increase at the edges or the insertion of thin mylar foil around the frame's edges. The last electrode in the structure, made with a printed-circuit board, is the only one equipped with electronics and is conveniently operated at ground potential. At regular intervals, four rows of pads are used to determine the coordinates of tracks in selected positions. Argon (90%) and methane (10%) comprise the gas filling.

Peisert, A.; Charpak, G.; Sauli, F.; Viezzoli, G.

1984-02-01T23:59:59.000Z

247

ANALYSIS OF THE AXIAL GAP VS FIBERBOARD MOISTURE CONTENT IN A 9975 SHIPPING PACKAGE  

SciTech Connect (OSTI)

The fiberboard assembly within a 9975 shipping package contains a modest amount of moisture, which can migrate to the cooler regions of the package when an internal heat load is present. Typically, this leads to increased moisture levels in the bottom fiberboard layers, along with elevated chloride levels which can leach from the fiberboard. Concerns have been raised that this condition could lead to corrosion of the stainless steel drum. It has been postulated that checking the axial gap at the top of the package against the current 1 inch maximum criterion provides a sufficient indication regarding the integrity of the fiberboard and drum. This report estimates the increase in axial gap that might be expected for a given moisture increase in the bottom fiberboard layers, and the likelihood that the increase will create a nonconforming condition that will lead to identification of the moisture increase. Using data relating the fiberboard moisture content with the degree of compaction under load, the present analysis indicates that the axial gap will increase by 0.282 inch as the bottom fiberboard layers approach the saturation point. This increase will cause approximately 58% of packages with otherwise nominal package component dimensions to fail the axial gap criterion, based on a survey of axial gap values recorded in K-Area surveillance activities. As the moisture content increases above saturation, the predicted increase in axial gap jumps to 0.405 inch, which would result in 92% or more of all packages failing the axial gap criterion. The data and analysis described in this report are specific to cane fiberboard. While it is expected that softwood fiberboard will behave similarly, such behavior has not yet been demonstrated.

Daugherty, W.

2013-09-30T23:59:59.000Z

248

Real-time seam tracking for rocket thrust chamber manufacturing  

SciTech Connect (OSTI)

A sensor-based control approach for real-time seam tracking of rocket thrust chamber assemblies has been developed to enable automation of a braze paste dispensing process. This approach utilizes a non-contact Multi-Axis Seam Tracking (MAST) sensor to track the seams. Thee MAST sensor measures capacitance variations between the sensor and the workpiece and produces four varying voltages which are read directly into the robot controller. A PID control algorithm which runs at the application program level has been designed based upon a simple dynamic model of the combined robot and sensor plant. The control algorithm acts on the incoming sensor signals in real-time to guide the robot motion along the seam path. Experiments demonstrate that seams can be tracked at 100 mm/sec within the accuracy required for braze paste dispensing.

Schmitt, D.J.; Novak, J.L. [Sandia National Labs., Albuquerque, NM (United States); Starr, G.P. [New Mexico Univ., Albuquerque, NM (United States); Maslakowski, J.E. [Rockwell International Corp., Canoga Park, CA (United States). Rocketdyne Div.

1993-11-01T23:59:59.000Z

249

Readout of TPC Tracking Chambers with GEMs and Pixel Chip  

SciTech Connect (OSTI)

Two layers of GEMs and the ATLAS Pixel Chip, FEI3, have been combined and tested as a prototype for Time Projection Chamber (TPC) readout at the International Linear Collider (ILC). The double-layer GEM system amplifies charge with gain sufficient to detect all track ionization. The suitability of three gas mixtures for this application was investigated, and gain measurements are presented. A large sample of cosmic ray tracks was reconstructed in 3D by using the simultaneous timing and 2D spatial information from the pixel chip. The chip provides pixel charge measurement as well as timing. These results demonstrate that a double GEM and pixel combination, with a suitably modified pixel ASIC, could meet the stringent readout requirements of the ILC.

Kadyk, John; Kim, T.; Freytsis, M.; Button-Shafer, J.; Kadyk, J.; Vahsen, S.E.; Wenzel, W.A.

2007-12-21T23:59:59.000Z

250

Development of Glass Resistive Plate Chambers for INO  

E-Print Network [OSTI]

The India-based Neutrino Observatory (INO) collaboration is planning to build a massive 50kton magnetised Iron Calorimeter (ICAL) detector, to study atmospheric neutrinos and to make precision measurements of the parameters related to neutrino oscillations. Glass Resistive Plate Chambers (RPCs) of about 2m X 2m in size are going to be used as active elements for the ICAL detector. We have fabricated a large number of glass RPC prototypes of 1m X 1m in size and have studied their performance and long term stability. In the process, we have developed and produced a number of materials and components required for fabrication of RPCs. We have also designed and optimised a number of fabrication and quality control procedures for assembling the gas gaps. In this paper we will review our activities towards development of glass RPCs for the INO ICAL detector and will present results of the characterisation studies of the RPCs.

Satyanarayana Bheesette; for the INO collaboration

2008-10-26T23:59:59.000Z

251

Conceptual Design Report for the Extreme Ecosystems Test Chambers  

SciTech Connect (OSTI)

This conceptual design supports the creation of Extreme Ecosystems Test Chambers, which will replicate deep subsurface and subocean environments characterized by high pressure (2,000 psi) and subfreezing to high temperature (-4 to 300 degrees F) with differing chemical and saturation conditions. The design provides a system to support research and development that includes heat transfer, phase change issues in porous media, microbiology in extreme environments, and carbon sequestration and extraction. The initial system design is based on the research needs to support the commercial production of methane hydrates from subsurface sediments. The design provides for three pressure vessels: a Down Hole Test Vessel, a Vertical Multi-phase Test Vessel, and a Horizontal Multi-phase Test Vessel.

C. Barnes; J. Beller; K. Caldwell; K. Croft; R. Cherry; W. Landman

1998-12-01T23:59:59.000Z

252

IMPEDANCE OF ELECTRON BEAM VACUUM CHAMBERS FOR THE NSLS-II STORAGE RING.  

SciTech Connect (OSTI)

In this paper we discuss computation of the coupling impedance of the vacuum chambers for the NSLS-II storage ring using the electromagnetic simulator GdfidL [1]. The impedance of the vacuum chambers depends on the geometric dimensions of the cross-section and height of the slot in the chamber wall. Of particular concern is the complex geometry of the infrared extraction chambers to be installed in special large-gap dipole magnets. In this case, wakefields are generated due to tapered transitions and large vertical-aperture ports with mirrors near the electron beam.

BLEDNYKH,A.; KRINSKY, S.

2007-06-25T23:59:59.000Z

253

Liquid fuel vaporizer and combustion chamber having an adjustable thermal conductor  

DOE Patents [OSTI]

The efficiency and effectiveness of apparatuses for vaporizing and combusting liquid fuel can be improved using thermal conductors. For example, an apparatus having a liquid fuel vaporizer and a combustion chamber can be characterized by a thermal conductor that conducts heat from the combustion chamber to the vaporizer. The thermal conductor can be a movable member positioned at an insertion depth within the combustion chamber that corresponds to a rate of heat conduction from the combustion chamber to the vaporizer. The rate of heat conduction can, therefore, be adjusted by positioning the movable member at a different insertion depth.

Powell, Michael R; Whyatt, Greg A; Howe, Daniel T; Fountain, Matthew S

2014-03-04T23:59:59.000Z

254

Operation of {sup 3}He Proportional Chambers in High Gamma Radiation Fields  

SciTech Connect (OSTI)

Operation of {sup 3}He proportional chambers with irradiated fissile materials is limited because of the sensitivity of these chambers to gamma ray events. The optimum performance of these chambers is achieved with proper selection of an additive gas to the chambers and with proper choice of preamplifier and linear amplifier time constants. The counting efficiency of a 4-atm, {sup 3}He-CO2 chamber is improved from 35% to 43% in a 200 R/hr gamma radiation field by decreasing the linear amplifier time constant. Likewise, the counting efficiency of a 1-atm, {sup 3}He-CF4 is improved from 11% to 14% in a 200 R/hr gamma radiation field by decreasing the linear amplifier time constant. The 4-atm, {sup 3}He-CO2 1-in.-OD chamber has a higher efficiency than the 1-atm, {sup 3}He-CF4 1-in.-OD chamber although the energy resolution of the 3 He-CF4 chamber is better than that for the {sup 3}He-CO2 chamber.

Hill, N.W.; Miller, V.C.; Valentine, T.E.; Williams, J.A.

1999-09-01T23:59:59.000Z

255

Beam quality corrections for parallel-plate ion chambers in electron reference dosimetry  

Science Journals Connector (OSTI)

Current dosimetry protocols (AAPM, IAEA, IPEM, DIN) recommend parallel-plate ionization chambers for dose measurements in clinical electron beams. This study presents detailed Monte Carlo simulations of beam quality correction factors for four different types of parallel-plate chambers: NACP-02, Markus, Advanced Markus and Roos. These chambers differ in constructive details which should have notable impact on the resulting perturbation corrections, hence on the beam quality corrections. The results reveal deviations to the recommended beam quality corrections given in the IAEA TRS-398 protocol in the range of 0%–2% depending on energy and chamber type. For well-guarded chambers, these deviations could be traced back to a non-unity and energy-dependent wall perturbation correction. In the case of the guardless Markus chamber, a nearly energy-independent beam quality correction is resulting as the effects of wall and cavity perturbation compensate each other. For this chamber, the deviations to the recommended values are the largest and may exceed 2%. From calculations of type-B uncertainties including effects due to uncertainties of the underlying cross-sectional data as well as uncertainties due to the chamber material composition and chamber geometry, the overall uncertainty of calculated beam quality correction factors was estimated to be

K Zink; J Wulff

2012-01-01T23:59:59.000Z

256

SciTech Connect: ON THE ANALYSIS OF BUBBLE CHAMBER TRACKS  

Office of Scientific and Technical Information (OSTI)

by such analysis. The discussion is based largely on experience gained in performing hydrogen bubble chamber experiments with the University of California's Bevatron (6-Bev proton...

257

Mixed reactant single chamber fuel cell, using products generated from the electrolysis of an aqueous electrolyte.  

E-Print Network [OSTI]

??A Mixed Reactant Single Chamber (MRSC) Fuel Cell is a relatively recent concept in the field of fuel cell engineering originally developed in the late… (more)

Jost, William C.

2008-01-01T23:59:59.000Z

258

Diagnostics of discharge channels for neutralized chamber transport in heavy ion fusion  

E-Print Network [OSTI]

ber of a heavy ion beam fusion reactor has many attractivein the reactor chamber for heavy ion fusion in preformedfusion. Controlled break- down and channel stability at reactor-

2002-01-01T23:59:59.000Z

259

The axial gas-dynamic forces acting on the rotor of a small gas-turbine engine  

Science Journals Connector (OSTI)

The exact determination is discussed of the axial gas-dynamic forces acting on the rotor of a gas-turbine engine (GTE), which influence reliability....

S. S. Evgen’ev; R. R. Zalyaev

2007-03-01T23:59:59.000Z

260

Axial Distributions of Spectral Line Intensities in the Arc Under the Influence of External Rotating Magnetic Field  

Science Journals Connector (OSTI)

The influence of external rotating magnetic field (RMF) on the electric arc plasma, and therefore the axial distributions of the spectral line intensities and the atomic...

Pavlovic, B V; Mihailidi, T A

1981-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "axial magma chamber" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Production of low axial energy spread ion beams with multicusp sources  

SciTech Connect (OSTI)

Multicusp ion sources are capable of producing ions with low axial energy spread which are necessary in applications such as: ion projection lithography (IPL) and focused ion beams for the next generation lithographic tools and nuclear science experiments such as radioactive ion beam production. The axial ion energy spread for multicusp source is approximately 6 eV which is too large for IPL and radioactive ion beam applications. The addition of a magnetic filter which consists of a pair of permanent magnets to the multicusp source reduces the energy spread considerably. The reduction is due to the improvement in the uniformity of the axial plasma potential distribution in the discharge region. Axial ion energy spread of the filament driven ion source has been measured using three different techniques. In all cases, it was found to be less than 2 eV. Energy spread of the radio frequency (RF) driven source has also been explored, and it was found to be less than 3 eV with the proper RF-shielding. A new multicusp source configuration has been designed and constructed to further reduce the energy spread. To achieve a more uniform axial plasma potential distribution, a cylindrical magnetic filter has been designed and constructed for a 2-cm-diameter source. This new source configuration, the co-axial source, is new in its kind. The energy spread in this source has been measured to be a record low of 0.6 eV. Because of the novelty of this device, some plasma parameters inside the source have been studied. Langmuir probe has been used to measure the plasma potential, the electron temperature and the density distribution.

Lee, Y.H.Y. [Univ. of California, Berkeley, CA (United States)

1998-05-01T23:59:59.000Z

262

Xenon-induced axial power oscillations in the 400 MW PBMR  

Science Journals Connector (OSTI)

The redistribution of the spatial xenon concentration in the 400 MW Pebble Bed Modular Reactor (PBMR) core has a non-linear, time-dependent feedback effect on the spatial power density during several types of operational transient events. Due to the inherent weak coupling that exists between the iodine and xenon formation and destruction rates, as well as the complicating effect of spatial variance in the thermal flux field, reactor cores have been analyzed for a number of decades for the occurrence and severity of xenon-induced axial power oscillations. Of specific importance is the degree of oscillation damping exhibited by the core during transients, which involves axial variations in the local power density. In this paper the TINTE reactor dynamics code is used to assess the stability of the current 400 MW PBMR core design with regard to axial xenon oscillations. The focus is mainly on the determination of the inherent xenon and power oscillation damping properties by utilizing a set of hypothetical control rod insertion transients at various power levels. The oscillation damping properties of two 100%–50%–100% load-follow transients, one of which includes the de-stabilizing axial effects of moving control rods, are also discussed in some detail. The study shows that, although first axial mode oscillations do occur in the 400 MW PBMR core, the inherent damping of these oscillations is high, and that none of the investigated load-follow transients resulted in diverging oscillations. It is also shown that the PBMR core exhibits no radial oscillation components for these xenon-induced axial power oscillations.

Gerhard Strydom

2008-01-01T23:59:59.000Z

263

Numerical investigation of flow structure and mixed convection heat transfer of impinging radial and axial jets  

SciTech Connect (OSTI)

Mixed convection flow fields and heat transfer of partially enclosed axial and radial laminar jets impinging on a heated flat plate have been investigated from the numerical solution of incompressible unsteady Navier-Stokes and energy equations with a Boussinesq approximation. For mixed convection flow at Re = 200, steady flow has not been observed for either the radial or the axial jet. For the smallest Grashof number (Gr = 10,000), periodic solutions have been obtained. With Gr = 40,000 nonsteady nonperiodic (chaotic) flow appears. Free convection may increase that heat transfer by more than 200%.

Potthast, F.; Laschefski, H.; Mitra, N.K. (Ruhr-Univ. Bochum (Germany). Inst. fuer Thermo- und Fluiddynamik); Biswas, G. (Indian Inst. of Tech., Kanpur (India). Dept. of Mechanical Engineering)

1994-08-01T23:59:59.000Z

264

Investigation of the axial and radial thrusts in a centrifugal pump  

E-Print Network [OSTI]

Major Subject: Mechanical Engineering INVESTIGATION QF THE AXIAL AND RADIAL THRUSTS IN A CENTRIFUGAL PUMP A Thesis by CHQNG HWAN PARK Approved as to style and content by: eter Jenkins (C 'rman of Committee) Dr Srrra un aram (Member) Dr. R. R... of absolute flow velocity at outlet of impeller (ft/sec) Fa Fb diameter (in) axial thrust (lb) force acting on the back-faces of impeller (lb) Fr Hd H Hs Ht kx kx Pd P(r) force acting on the frontal face of impeller (lb) radial thrust (lb...

Park, Chong Hwan

1984-01-01T23:59:59.000Z

265

Analysis of the behavior of 5 axially loaded single piles in sand at Hunter's Point  

E-Print Network [OSTI]

ANALYSIS OF THE BEHAVIOR OF 5 AXIALLY LOADED SINGLE PILES IN SAND AT HUNTER'S POINT A Thesis by CHER MIN RON Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirement for the degree... of MASTER OF SCIENCE May 1989 Major Subject; Civil Engineering ANALYSIS OF THE BEHAVIOR OF 5 AXIALLY LOADED SINGLE PILES IN SAND AT HUNTER'S POINT A Thesis by GHEE MIN RON Approved as to style and content by: Jean-Louis Briaud Chairman of Committee...

Kon, Chee Min

1989-01-01T23:59:59.000Z

266

Nucleon observables and axial charges of other baryons using twisted mass fermions  

E-Print Network [OSTI]

We present results on the nucleon scalar, axial and tensor charges, as well as, on the first moments of the unpolarized, polarized and transversity parton distributions using $N_f=2$ and $N_f=2+1+1$ twisted mass fermions. These include an ensemble that yields the physical value of the ratio of the nucleon to the pion mass. Results on the axial charges of hyperons and charmed baryons are also presented for a range of pion masses including the physical one.

Constantia Alexandrou; Martha Constantinou; Kyriakos Hadjiyiannakou; Karl Jansen; Christos Kallidonis; Giannis Koutsou

2014-11-13T23:59:59.000Z

267

Numerical Study of Unsteady Detonation Wave Propagation in a Supersonic Combustion Chamber  

E-Print Network [OSTI]

Numerical Study of Unsteady Detonation Wave Propagation in a Supersonic Combustion Chamber T.H. Yi detonation waves in a supersonic flow in one-dimensional tube and two- dimensional wedged chamber parameters. Various features including a vortex are observed. 1 Introduction Detonation wave propagation

Texas at Arlington, University of

268

Computation of Neutral Gas Flow From a Hall Thruster Into a Vacuum Chamber  

E-Print Network [OSTI]

to model a cold flow of xenon gas expanding from a Hall thruster into a vacuum chamber. The simulations are performed for the P5 Hall thruster operating in a large vacuum tank at the University of Michigan chamber are varied. A key physical parameter in the simulations concerns the probability that a xenon atom

Walker, Mitchell

269

Threats, design limits and design windows for laser IFE dry wall chambers  

E-Print Network [OSTI]

Threats, design limits and design windows for laser IFE dry wall chambers A. Rene´ Raffray-drive targets and a dry wall chamber. The dry wall must accommodate the ion and photon threat spectra from. The neutron energy is deposited deeper in the first wall and blanket and does not represent a major threat

Raffray, A. René

270

EFFECTS OF CHAMBER GEOMETRY AND GAS PROPERTIES ON HYDRODYNAMIC EVOLUTION OF IFE Zoran Dragojlovic1  

E-Print Network [OSTI]

-dependent response of the chamber environment between target ignitions. The fusion burn following the target ignition Dragojlovic1 and Farrokh Najmabadi2 Department of Electrical & Computer Engineering and Center for Energy releases large quantities of energy into the chamber. This energy should be removed and the environment

Najmabadi, Farrokh

271

Automated Monitoring of Soil Respiration: A Moving Chamber Design Nelson T. Edwards* and Jeffery S. Riggs  

E-Print Network [OSTI]

growthdifferential mode, and equivalent flow rates of reference gas (ambient air) and sample gas (air exiting chamber by establishing chamber when closed, provided an airtight seal. This feature and the temperature response rates continuously monitored soil temperature, or air temper- even in an environment with highly

272

Hydrogen production using single-chamber membrane-free microbial electrolysis cells  

E-Print Network [OSTI]

efficiencies of hydrogen fuel cells in converting hydrogen to electricity. The development of advancedHydrogen production using single-chamber membrane-free microbial electrolysis cells Hongqiang Hu., Hydrogen production using single-chamber membrane-free microbial electrol- ysis cells, Water Research (2008

Tullos, Desiree

273

A local limit theorem for random walks on the chambers of ~A2 buildings  

E-Print Network [OSTI]

A local limit theorem for random walks on the chambers of ~A2 buildings James Parkinson and Bruno. In this paper we outline an approach for analysing random walks on the chambers of buildings. The types of walks that we consider are those which are well adapted to the structure of the building: Namely walks

Paris-Sud XI, Université de

274

The American Chamber of Commerce of Trinidad & Tobago | Department of  

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

The American Chamber of Commerce of Trinidad & Tobago The American Chamber of Commerce of Trinidad & Tobago The American Chamber of Commerce of Trinidad & Tobago May 13, 2008 - 12:00pm Addthis Remarks As Prepared for Delivery by Secretary Bodman Thank you, Raymond. I appreciate the Chamber organizing this gathering this morning. The American Chamber here on Trinidad and Tobago is an important regional voice in support of the free market, so I want to commend you for hosting the Business Future of the Americas conference next month. Having spent most of my career in the private sector, it is always rewarding to be among colleagues from the business community. I'm also quite pleased to be back in Trinidad & Tobago, having done business here during my time at Cabot Corporation. I've always been impressed with this nation's government, its people and

275

MHK Technologies/Multi Resonant Chambers MRC 1000 | Open Energy Information  

Open Energy Info (EERE)

Resonant Chambers MRC 1000 Resonant Chambers MRC 1000 < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Multi Resonant Chambers MRC 1000.jpg Technology Profile Primary Organization ORECon Technology Resource Click here Wave Technology Type Click here Oscillating Water Column Technology Readiness Level Click here TRL 5 6 System Integration and Technology Laboratory Demonstration Technology Description A 1 5MW Multi Resonant Chamber MRC using Oscillating Water Column OWC principles Consists of 3 x 500kW independent chambers each with a Dresser Rand HydroAir turbine driving an induction generator Full power conversion system delivers grid compliant power 1 5MW 33kV 60Hz to shore Device is tension moored to maximise power capture and minimise footprint All maintenance is done on board No moving parts in the water Turbines are low speed 300rpm high efficiency 75 and low noise

276

U.S. Chamber of Commerce Biofuels Dialogue Series: Outlook for an Emerging  

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

Chamber of Commerce Biofuels Dialogue Series: Outlook for an Chamber of Commerce Biofuels Dialogue Series: Outlook for an Emerging Global Biofuels Market U.S. Chamber of Commerce Biofuels Dialogue Series: Outlook for an Emerging Global Biofuels Market January 29, 2008 - 10:53am Addthis Remarks as Prepared For Delivery by Secretary Bodman Thank you very much, Bruce, for that kind introduction. My thanks also to Tom Donahue and the leadership of the Chamber for inviting me to be with you today. I was quite pleased to hear that the Chamber was sponsoring this event. As anyone who knows me - or has heard me speak recently - can tell you, the biofuels industry is a favorite topic of mine. In my view, advanced biofuels offer tremendous promise for helping our nation to bring about a new energy future-one that is cleaner, more sustainable, more affordable,

277

Development of Aluminium Vacuum Chambers for the LHC Experiments at CERN  

E-Print Network [OSTI]

Beam losses may cause activation of vacuum chamber walls, in particular those of the Large Hadron Collider (LHC) experiments. For the High Luminosity (HL-LHC), the activation of such vacuum chambers will increase. It is therefore necessary to use a vacuum chamber material which interacts less with the circulating beam. While beryllium is reserved for the collision point, a good compromise between cost, availability and transparency is obtained with aluminium alloys; such materials are a preferred choice with respect to austenitic stainless steel. Manufacturing a thin-wall aluminium vacuum chamber presents several challenges as the material grade needs to be machinable, weldable, leak-tight for small thicknesses, and able to withstand heating to 250°C for extended periods of time. This paper presents some of the technical challenges during the manufacture of these vacuum chambers and the methods for overcoming production difficulties, including surface treatments and Non-Evaporable Getter (NEG) thin-film coat...

Gallilee, M; Costa-Pinto, P; Lepeule, P; Perez-Espinos, J; Marques Antunes Ferreira, L; Prever-Loiri, L; Sapountzis, A

2014-01-01T23:59:59.000Z

278

Pressure pulsations in combustion chambers of large gas turbines  

SciTech Connect (OSTI)

Flame instabilities and pressure pulsations have been measured in three different types of gas turbine combustors. These are the single and twin silo (such as the ABB GT13E and the Siemens V94.2), the annular combustion chamber (ABB GT 13E2, Siemens V84.3A, etc), and the multi-can combustors common on GEC-EGT gas turbines. Pressure pulsations are mostly resonant. They are interpreted with help of an acoustical model. Non-resonant modes at low frequencies (flame flicker) are ascribed to imperfect mixing especially in premix burners. At higher frequencies they are often due to vortices from the burners. Modifications of the burners, changes in the geometry of the liners and the addition of acoustical dampers are means to abate flame instabilities and the associated resonances. Judicious ways to run the gas turbine can help to avoid them. The efficiency of acoustical dampers of the Helmholtz type has been investigated experimentally and with model predictions.

Verhage, A.J.L.; Stevens, P.M.P.

1998-07-01T23:59:59.000Z

279

Performance characteristics of a low pressure cyclone for axial-flow fan exhausts  

E-Print Network [OSTI]

pneumatically convey lint fiber to the first-stage lint cleaner. typically, covered condenser drums with fine mesh screens are the abatement devices used on a)axial-flow fan exhausts. A new ID2D Low Pressure Cyclone (LPC) was developed that could be used...

Simpson, Shay Lynn

2012-06-07T23:59:59.000Z

280

EXPERIMENTAL INVESTIGATIONS ON THE DESIGN OF A DUCTED COUNTER-ROTATING AXIAL FLOW FANS SYSTEM  

E-Print Network [OSTI]

[] Number of blades FR [] Front rotor R [mm] Blade radius RR [] Rear rotor CRS [] Counter-rotating system W to a conventional rotor or to a rotor-stator stage. The study of the variation of the rotation rates ratio show of the axial distance be- tween rotors does not seem to change the overall per- formances. This system has thus

Boyer, Edmond

Note: This page contains sample records for the topic "axial magma chamber" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

A study of swirl and axial velocity profile effects on orifice flowmeters  

E-Print Network [OSTI]

with [ ] ratios of 0.43, 0.45, 0.484, 0.55, 0.6, 0.65, 0.7 and 0.726 are studied at both flow rates. The response of each orifice meter to the disturbance is measured by determining the axial pressure distribution near the orifice plate, and by determining...

Hauglie, Jayden Edward

1994-01-01T23:59:59.000Z

282

Axial and radial preliminary results of the neutron radiation from miniature plasma focus devices.  

E-Print Network [OSTI]

Axial and radial preliminary results of the neutron radiation from miniature plasma focus devices. Introduction. The plasma focus (PF) is a dense transient plasma source of high temperature, when it operate of understanding the physics related to the plasma focus working at this limit of unexplored energy, b) to develop

Paris-Sud XI, Université de

283

Deposition of tungsten nitride thin films by plasma focus device at different axial and angular positions  

Science Journals Connector (OSTI)

Tungsten nitride thin films were deposited on stainless steel–304 substrates by using a low energy (2 kJ) Mather type plasma focus device. X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and microhardness are used to study the surface of treated samples. The XRD analysis shows that the degree of crystallinity of deposited thin films strongly depends on axial and angular positions of samples. The SEM micrographs of the deposited films at different angular positions (0°, 10° and 30°) and axial position of 8 cm show that the content of WN sub-micro crystalline structures on the surface of deposited films decreased with increasing the angle with respect to anode axis. From AFM results we observe that for the sample deposited at 8 cm and 0° axial and angular positions, respectively, the most uniform surface and the most homogenous distribution of grains are obtained. Also the hardness results show that the highest mechanical hardness is obtained when the film is deposited at 8 cm and 0° axial and angular positions, respectively.

M.T. Hosseinnejad; M. Ghoranneviss; G.R. Etaati; M. Shirazi; Z. Ghorannevis

2011-01-01T23:59:59.000Z

284

Abstract This paper investigates the steady-state and the transient performances of an axial magnetic coupling by using  

E-Print Network [OSTI]

and measurements. Index Terms-- Analytical model, magnetic field, axial coupling, permanent magnets, pull-pitch ratio p Pole-pair number Torque angle Br Remanence of the permanent magnets K Torsional stiffness II tolerate shaft misalignment. As shown in Fig. 1, the studied axial magnetic coupling consists of two discs

Paris-Sud XI, Université de

285

Progress In Electromagnetics Research M, Vol. 35, 173182, 2014 Three-Dimensional Analytical Model for an Axial-Field  

E-Print Network [OSTI]

--In this paper, we propose an analytical method for modeling a permanent magnets axial field magnetic coupling. Shaft Rout Magnets Soft-Iron yoke h h Rin e To load From motor Magnetic coupling Figure 1. Structure equipped with axially magnetized permanent magnets (PMs). The PMs are glued on an iron yoke to form a north

Paris-Sud XI, Université de

286

Analysis and Design of a High Power Density Axial Flux Permanent Magnet Linear Synchronous Machine Used for Stirling System  

Science Journals Connector (OSTI)

a high power density axial flux permanent magnet linear synchronous machine and the stirling system will be introduced. This machine is a tubular axial flux permanent magnet machine. It comprises two parts: stator and mover. With the 2D finite-element ... Keywords: permanent magnet, stirling engine, linear motor

Ping Zheng; Xuhui Gan; Lin Li

2010-09-01T23:59:59.000Z

287

Hydrogen bonding preference of equatorial versus axial hydroxyl groups in pyran and cyclohexane rings in organic crystals  

E-Print Network [OSTI]

Paper Hydrogen bonding preference of equatorial versus axial hydroxyl groups in pyran of the hydrogen bonding counts in crystalline pyranose monosaccharides, we noticed that equatorial hydroxyls formed more hydrogen bonds, on average, than axial groups. A survey of the Cambridge Structural Database

de Gispert, AdriĂ 

288

Using large environmental chamber technique for gaseous contaminant removal equipment test  

SciTech Connect (OSTI)

The US Association of Home Appliance Manufacturers (AHAM) has set a voluntary standard for testing the initial dust-removal capacity of portable air cleaners. In the authors` test of portable air cleaners for the local consumer council, the AHAM method was extended to test the initial removal capacity for gaseous phase pollutants. Also, carbon filters` efficiency change over time in toluene removal on a number of air cleaners was tested. In using a large chamber to carry out these tests, the chamber wall adsorption and re-emission effects were experimentally quantified. These tests indicated that a large chamber, with its wall surface adsorption controlled, is simple and robust to use to quantify the initial cleaning capacity for gaseous phase pollutants. Based on these test results, a large chamber method is proposed to test the performance lifetimes of portable air cleaners. The system advantages of the method over the in-duct performance life test methods are that no continuous air-cleaning system is required and that the chamber`s humidity and temperature can be maintained at the desired values more easily with the combination of a unitary dehumidifier and a bubbler system. This paper will present the trial results with portable air cleaner tests and discuss the large environmental chamber techniques.

Niu, J.; Tung, T.C.W.; Chui, V.W.Y. [Hong Kong Polytechnic Univ. (Hong Kong). Dept. of Building Services Engineering

1998-12-31T23:59:59.000Z

289

Plastic ball and streamer chamber experiments at the Bevalac  

SciTech Connect (OSTI)

Single particle inclusive experiments, and experiments that additionally measure a few correlations like the associated multiplicity, have provided the main contribution to our present understanding of high energy heavy ion collisions. The results from those experiments are in overall agreement with calculations of the cascade and hydrodynamical models. In the cascade model the collision of two nuclei is simulated as a cascade of nucleon-nucleon collisions using measured N-N cross sections. The hydrodynamical model, on the other hand, describes the nuclear collision as that of two fluids and makes use of a nuclear equation of state relating thermal and compressional energy densities to pressure. The pressure field dominates the expansion phase and leads to collective flow of the reaction products in a preferred direction. The observation of such effects in inclusive experiments is not well established. Collective effects that manifest themselves in the shape of the event in phase space are expected to be seen best in the new complete event detectors that measure the final state as exclusively as presently possible by measuring most of the charged particles emitted in the reaction. In addition, those detectors are well suited to test macroscopic concepts such as equilibrium and temperature. Global methods like the sphericity or thrust analysis take into account all the correlations measured in the event and are specially designed to determine the shape of an event in phase space and thus to define a reaction plane. Recent data from the Plastic Ball and the streamer chamber experiments, the first complete event detectors in use at the Bevalac, are presented in this report.

Ritter, H.G.

1982-07-01T23:59:59.000Z

290

Interaction between mantle-derived and crustal calc-alkaline magmas in the petrogenesis of the Paleocene Sifton Range volcanic complex, Yukon, Canada  

Science Journals Connector (OSTI)

The uplifted plutons of the eastern Coast Plutonic Complex (CPC) of the northern Canadian Cordillera are in contact with coeval volcanic suites of the early Tertiary Sloko-Skukum Group, offering a unique opportunity to address the relationship between subduction-related, continental calc-alkaline volcanic sequences and their coeval granitoid suites. The Sifton Range volcanic complex (SRVC) of southwestern Yukon is intruded by CPC granites and displays a subduction-related geochemical signature with depletions in HFSE relative to LILE. The volcanic rocks range between medium- and high-K orogenic suites, and define a calc-alkaline fractionation trend. The epizonal potassium–feldspar granites are chemically similar to the SRVC rhyolites, and are characterized by highly fractionated LREE (LaN / SmN = 5–11), enrichments in LILE and Th (12–18 ppm). The SRVC exhibits a striking relationship between rock composition and style of eruption, with a reduction in abundance of lavas with increasing SiO2 being correlated with the appearance of felsic pyroclastic rocks and granitic plutonism. Thermodynamic crystal fractionation models of the compositional interval between basaltic and dacitic andesite (52–61 wt.% SiO2) are consistent with evolution at moderately hydrous (1.5 wt.% H2O), upper crustal (1.5 kbar) conditions, and fO2 close to the QFM buffer. Neither assimilation-fractional crystallization (AFC), nor binary magma mixing models are capable of explaining the anomalously elevated Th contents in the SRVC felsic lavas and granites. Furthermore, unrealistically high contamination factors (r > 2.5) are required in AFC models to attain the incompatible-element concentrations of the SRVC granite and rhyolites, suggesting they represent distinct melts derived by anatexis of enriched upper crust, rather than the evolved products of the mafic SRVC magma. Changes in crystallinity during evolution of the SRVC magmas imply an abrupt rise in effective viscosity (from 106 to 1010 Pa s) near the andesite–dacite transition as a result of the flocculation of plagioclase phenocrysts. The resultant increase in shear strength impeded crystal fractionation and eruption of lavas, and may account for the decrease in the abundance of flows with more than 62 wt.% SiO2. The onset of explosive volcanism at c.a. 68 wt.% SiO2 approximately coincides with the calculated saturation point of H2O at 1.5 kbar in the hybridized dacite magmas. Alternating mafic and felsic volcanic stratigraphy along with the presence of compositionally bimodal pyroclastics and mixed phenocrysts in the SRVC dacites suggest that mantle-derived magmas and crustal melts coexisted in a zoned magmatic column undergoing episodic injection of juvenile melts. Sudden release of volatiles from the hybrid dacitic magmas along the interface with the overlying anatectic crystal mush may have triggered the cycle of explosive eruptions of dominantly rhyolitic ejecta. The consequent loss of volatiles further promoted feldspar crystallization eventually favouring magma stagnation and plutonism.

Aleksandar Miškovi?; Don Francis

2006-01-01T23:59:59.000Z

291

A study of the response of a gas ionization chamber to different sources of ionizing radiation  

E-Print Network [OSTI]

ranged from a few keV to 20 MeV and peaked at 5 MeV. The neutrons were produced by the (n, n) reaction o(5. 16MeV)+ Be ~ C+n( 5MeV). A 2-in thick lead brick was placed in front of the chamber to absorb the soft 7-rays emitted from the source along... with the neutrons. The source was kept 9in away from the chamber during all runs. Data were taken for both gas mixtures with the cathode pad facing the source and also with the chamber turned around. In addition to these measurements, four more runs were made...

Zamble?-Die?guez, Filiberto Edmundo

2012-06-07T23:59:59.000Z

292

Power and Public Chambers in the development of civil society in Russia  

Science Journals Connector (OSTI)

Abstract Embodying a state vision of how civil society ought to function and be designed by the authorities, Public Chambers in Russia have been criticized as means of state control. This state dominance is the starting point in this article, which asks what room to manoeuvre a regional Public Chamber has. Drawing upon fieldwork this article examines how members and local observers of the Public Chamber give meaning to this activity. The analysis assesses the role of state dominance, discussion of routines and responses to local demands, and concludes that these incremental developments form civil society in Russia.

Kirsti Stuvřy

2014-01-01T23:59:59.000Z

293

High Accuracy, Two-Dimensional Read-Out in Multiwire Proportional Chambers  

DOE R&D Accomplishments [OSTI]

In most applications of proportional chambers, especially in high-energy physics, separate chambers are used for measuring different coordinates. In general one coordinate is obtained by recording the pulses from the anode wires around which avalanches have grown. Several methods have been imagined for obtaining the position of an avalanche along a wire. In this article a method is proposed which leads to the same range of accuracies and may be preferred in some cases. The problem of accurate measurements for large-size chamber is also discussed.

Charpak, G.; Sauli, F.

1973-02-14T23:59:59.000Z

294

Voltage Oscillations in Single-Chamber Fuel Cells operating under a C3H8 / O2 mixture.  

E-Print Network [OSTI]

1 Voltage Oscillations in Single-Chamber Fuel Cells operating under a C3H8 / O2 mixture. Geoffroy : Jean-Paul Viricelle, viricelle@emse.fr Phone : 33 4 77 42 02 52 Abstract : Single-Chamber Fuel Cells this behaviour. Keywords: Single Chamber Fuel Cell, Propane, Oscillation, Anode. 1. Introduction Solid Oxide Fuel

Paris-Sud XI, Université de

295

Neutron And Gamma Detector Using An Ionization Chamber With An Integrated  

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

Neutron And Gamma Detector Using An Ionization Chamber Neutron And Gamma Detector Using An Ionization Chamber Neutron And Gamma Detector Using An Ionization Chamber With An Integrated Body And Moderator A detector for detecting neutrons and gamma radiation includes a cathode that defines an interior surface and an interior volume. Available for thumbnail of Feynman Center (505) 665-9090 Email Neutron And Gamma Detector Using An Ionization Chamber With An Integrated Body And Moderator A detector for detecting neutrons and gamma radiation includes a cathode that defines an interior surface and an interior volume. A conductive neutron-capturing layer is disposed on the interior surface of the cathode and a plastic housing surrounds the cathode. A plastic lid is attached to the housing and encloses the interior volume of the cathode forming an

296

Study of Low Speed Flow Cytometry for Diffraction Imaging with Different Chamber  

E-Print Network [OSTI]

for optimization of the chamber design and improvement of the cell positioning accuracy for study of slow moving utilize a sheath nozzle with a conical end or orifice for hydrodynamic focusing the fluid injected

297

Organic Aerosol Formation from Photochemical Oxidation of Diesel Exhaust in a Smog Chamber  

Science Journals Connector (OSTI)

Diluted exhaust from a diesel engine was photo-oxidized in a smog chamber to investigate secondary organic aerosol (SOA) production. Photochemical aging rapidly produces significant SOA, almost doubling the organic aerosol contribution of primary ...

Emily A. Weitkamp; Amy M. Sage; Jeffrey R. Pierce; Neil M. Donahue; Allen L. Robinson

2007-09-11T23:59:59.000Z

298

E-Print Network 3.0 - atlas mdt chambers Sample Search Results  

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

Page: << < 1 2 3 4 5 > >> 1 CHRISTOPH AMELUNG Date of birth July 14, 1971 (DetmoldGermany) Summary: on the optical alignment system of the ATLAS MDT chambers July 2002 -...

299

Ionisation chamber containing boron as a neutron detector in medical accelerator fields  

Science Journals Connector (OSTI)

......oxfordjournals.org August 2007 research-article POSTER Presentations Ionisation chamber containing boron...was partially supported by the Polish Ministry of Science and Higher Education under the grant No. 2P05D06530. The authors would......

M. Zielczynski; M. A. Gryzinski; N. Golnik; P. Tulik

2007-08-01T23:59:59.000Z

300

A multibeam radio-frequency ion source with a discharge chamber inside a resonator  

Science Journals Connector (OSTI)

The design of a multibeam ion source with a discharge chamber inside a half-wavelength radio-frequency (RF) resonator with a spiral load ... resonator. The RF oscillator operating at a frequency of 38 MHz is grou...

B. Yu. Bogdanovich; V. P. Zubovskii…

2008-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "axial magma chamber" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

E-Print Network 3.0 - argon imaging chamber Sample Search Results  

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

Centre de mathmatiques Collection: Mathematics 7 Bio390 Problem: Gas Laws thanks to Dr. J.F. Anderson, Summary: level on Earth. Inside the ground-level plastic chamber the...

302

The design, fabrication, and implications of a solvothermal vapor annealing chamber  

E-Print Network [OSTI]

This thesis documents the design, fabrication, use, and benefits of a prototype aluminum solvothermal vapor annealing chamber which facilitates the self-assembly of block copolymers (BCPs) on silicon wafers which are then ...

Porter, Nathaniel R., Jr

2013-01-01T23:59:59.000Z

303

Method of correcting eddy current magnetic fields in particle accelerator vacuum chambers  

DOE Patents [OSTI]

A method for correcting magnetic field aberrations produced by eddy currents induced in a particle accelerator vacuum chamber housing is provided wherein correction windings are attached to selected positions on the housing and the windings are energized by transformer action from secondary coils, which coils are inductively coupled to the poles of electro-magnets that are powered to confine the charged particle beam within a desired orbit as the charged particles are accelerated through the vacuum chamber by a particle-driving rf field. The power inductively coupled to the secondary coils varies as a function of variations in the power supplied by the particle-accelerating rf field to a beam of particles accelerated through the vacuum chamber, so the current in the energized correction coils is effective to cancel eddy current flux fields that would otherwise be induced in the vacuum chamber by power variations in the particle beam.

Danby, Gordon T. (Wading River, NY); Jackson, John W. (Shoreham, NY)

1991-01-01T23:59:59.000Z

304

Method of correcting eddy current magnetic fields in particle accelerator vacuum chambers  

DOE Patents [OSTI]

A method for correcting magnetic field aberrations produced by eddy currents induced in a particle accelerator vacuum chamber housing is provided wherein correction windings are attached to selected positions on the housing and the windings are energized by transformer action from secondary coils, which coils are inductively coupled to the poles of electro-magnets that are powered to confine the charged particle beam within a desired orbit as the charged particles are accelerated through the vacuum chamber by a particle-driving rf field. The power inductively coupled to the secondary coils varies as a function of variations in the power supplied by the particle-accelerating rf field to a beam of particles accelerated through the vacuum chamber, so the current in the energized correction coils is effective to cancel eddy current flux fields that would otherwise be induced in the vacuum chamber by power variations (dB/dt) in the particle beam.

Danby, G.T.; Jackson, J.W.

1990-03-19T23:59:59.000Z

305

Electron-Hadron shower discrimination in a liquid argon time projection chamber  

E-Print Network [OSTI]

By exploiting structural differences between electromagnetic and hadronic showers in a multivariate analysis we present an efficient Electron-Hadron discrimination algorithm for liquid argon time projection chambers, validated using Geant4 simulated data.

J. J. Back; G. J. Barker; A. J. Bennieston; S. B. Boyd; B. Morgan; Y. A. Ramachers

2012-10-08T23:59:59.000Z

306

Field calibration studies for ionisation chambers in mixed high-energy radiation fields  

Science Journals Connector (OSTI)

......roof over the accelerator measures only...activation of the PS vacuum chamber, measured after stop of the accelerator. A loss of protons...High Energy and Nuclear Physics 2003 Conference...high-energy accelerators. (2003) Doctoral......

C. Theis; D. Forkel-Wirth; M. Fuerstner; S. Mayer; Th. Otto; S. Roesler; H. Vincke

2007-08-01T23:59:59.000Z

307

Space Chamber Reaches Cold Target at Unprecedented Efficiency | U.S. DOE  

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

Space Chamber Reaches Cold Target at Unprecedented Efficiency Space Chamber Reaches Cold Target at Unprecedented Efficiency Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Funding Opportunities Nuclear Science Advisory Committee (NSAC) News & Resources Contact Information Nuclear Physics U.S. Department of Energy SC-26/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3613 F: (301) 903-3833 E: sc.np@science.doe.gov More Information » October 2012 Space Chamber Reaches Cold Target at Unprecedented Efficiency Thomas Jefferson Laboratory lends expertise in cryogenics developments. Print Text Size: A A A Subscribe FeedbackShare Page Click to enlarge photo. Enlarge Photo Image courtesy of NASA NASA's Space Environment Simulation Lab Chamber A, which is used by the

308

The Effect of Heat Treatments and Coatings on the Outgassing Rate of Stainless Steel Chambers  

SciTech Connect (OSTI)

The outgassing rates of four nominally identical 304L stainless steel vacuum chambers were measured to determine the effect of chamber coatings and heat treatments. One chamber was coated with titanium nitride (TiN) and one with amorphous silicon (a-Si) immediately following fabrication. One chamber remained uncoated throughout, and the last chamber was first tested without any coating, and then coated with a-Si following a series of heat treatments. The outgassing rate of each chamber was measured at room temperatures between 15 and 30 deg C following bakes at temperatures between 90 and 400 deg C. Measurements for bare steel showed a significant reduction in the outgassing rate by more than a factor of 20 after a 400 deg C heat treatment (3.5 x 10{sup 12} TorrL s{sup -1}cm{sup -2} prior to heat treatment, reduced to 1.7 x 10{ sup -13} TorrL s{sup -1}cm{sup -2} following heat treatment). The chambers that were coated with a-Si showed minimal change in outgassing rates with heat treatment, though an outgassing rate reduced by heat treatments prior to a-Si coating was successfully preserved throughout a series of bakes. The TiN coated chamber exhibited remarkably low outgassing rates, up to four orders of magnitude lower than the uncoated stainless steel. An evaluation of coating composition suggests the presence of elemental titanium which could provide pumping and lead to an artificially low outgassing rate. The outgassing results are discussed in terms of diffusion-limited versus recombination-limited processes.

Mamum, Md Abdullah A. [Old Dominion Univ., Norfolk, VA (United States); Elmustafa, Abdelmageed A, [Old Dominion Univ., Norfolk, VA (United States); Stutzman, Marcy L. [JLAB, Newport News, VA (United States); Adderley, Philip A. [JLAB, Newport News, VA (United States); Poelker, Matthew [JLAB, Newport News, VA (United States)

2014-03-01T23:59:59.000Z

309

Invention and History of the Bubble Chamber (LBNL Summer Lecture Series)  

ScienceCinema (OSTI)

Summer Lecture Series 2006: Don Glaser won the 1960 Nobel Prize for Physics for his 1952 invention of the bubble chamber at Berkeley Lab, a type of particle detector that became the mainstay of high-energy physics research throughout the 1960s and 1970s. He discusses how, inspired by bubbles in a glass of beer, he invented the bubble chamber and detected cosmic-ray muons.

Glaser, Don

2011-04-28T23:59:59.000Z

310

Dual-chamber plasma deposition of A-Si:H solar cells at high rates using disilane  

SciTech Connect (OSTI)

The use of a separated chamber deposition system for the fabrication of a-Si:H solar cells from disilane at high deposition rates results in a substantial improvement in short circuit current compared to that obtained from a single-chamber system. The spectral responses of cells fabricated in the dual-chamber mode are compared to those made in the single-chamber mode. The results are interpreted by assuming that the rate of removal of boron contaminants from the chamber is independent of deposition rate.

Rajeswaran, G.; Vanier, P.E.; Corderman, R.R.; Kampas, F.J.

1985-01-01T23:59:59.000Z

311

Electrophoretic Migration and Axial Diffusion of Individual Nanoparticles in Cylindrical Nanopores  

SciTech Connect (OSTI)

Membranes with straight, vertical nanopores have found widespread applications in chemical and biological sciences, including separation, detection, catalysis, and drug delivery. They can also serve as a model system to understand molecular behavior and fundamental mechanisms of separation, bridging the gap between conventional model systems such as flat surfaces and real chromatographic stationary phases such as micrometer-sized porous particles. We recently found that the axial motion of individual biomolecules inside nanopores can be significantly slower than in bulk solution. This suggests that either chromatographic adsorption was present and/or the viscosity inside the nanopores was unusually high. In this study, we measured the electrophoretic motion as well as the axial diffusion of individual nanoparticles in cylindrical alumina nanopores. We found that the electrophoretic mobilities and the diffusion coefficients of polystyrene nanoparticles were both substantially smaller compared to bulk solution independent of particle size or pore diameter. The results imply that the apparent solution viscosity in nanodomains is anomalous.

Han, Rui; Wang, Gufeng; Qi, Shengda; Ma, Changbei; Yeung, Edward S.

2012-08-01T23:59:59.000Z

312

Chapter 4 - Axial-Flow Turbines: Mean-Line Analysis and Design  

Science Journals Connector (OSTI)

This chapter begins with a historical perspective on the development of the modern axial turbine, which is now a highly advanced technology that is critical for aircraft propulsion and power generation. The basic analysis of axial turbines is covered, including velocity triangles and the principle mean-line relationships. The derivation of turbine efficiency from loss coefficients is presented as well as a detailed discussion of the various loss sources that lead to efficiency reduction. The main calculations used in the initial design of a multistage turbine are then detailed along with worked examples and comparisons between designs with low and high levels of reaction. Turbine efficiency correlations are also explored for different design styles. In the final sections, the centrifugal stresses in turbine rotor blades and the effects of turbine blade cooling are considered.

S.L. Dixon; C.A. Hall

2014-01-01T23:59:59.000Z

313

Synthesis, fabrication and characterization of Ge/Si axial nanowire heterostructure tunnel FETs  

SciTech Connect (OSTI)

Axial Ge/Si heterostructure nanowires allow energy band-edge engineering along the axis of the nanowire, which is the charge transport direction, and the realization of asymmetric devices for novel device architectures. This work reports on two advances in the area of heterostructure nanowires and tunnel FETs: (i) the realization of 100% compositionally modulated Si/Ge axial heterostructure nanowires with lengths suitable for device fabrication and (ii) the design and implementation of Schottky barrier tunnel FETs on these nanowires for high-on currents and suppressed ambipolar behavior. Initial prototype devices resulted in a current drive in excess of 100 {micro}A/{micro}m (I/{pi}D) and 10{sup 5} I{sub on}/I{sub off} ratios. These results demonstrate the potential of such asymmetric heterostructures (both in the semiconductor channel and metal-semiconductor barrier heights) for low-power and high performance electronics.

Picraux, Samuel T [Los Alamos National Laboratory; Dayeh, Shadi A [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

314

Comparison of the effects of pressure and axial load on tapered connections  

E-Print Network [OSTI]

. OO RX1RL FQHii [LBS. ) (XI Qs } 120. 00 ll1II. 00 Figure 41. Axial Force versus Hoop Stress-Test 1 4. 65 2 7/0 iN. RPI EL~E LUNG-. 362 I', sLL-NBQ 10. 4 & C/) ~el to 3N Th * ' 1, 3, 8 X~~ +Theoretical, 1, 10, 5, 6 18, 10 68, 6 o o G N..., 6 e 58 6 18, 10 0. 0 I ? ?- 21. 00 02. 00 20. 00 04 GG F00, 00 120. 00 RX1RL EQREi iLBS. 1 &Xloa ) Figure 43. Axial Force versus Longitudinal Stress-Test T2. 67 o o 4 I/2 IN. BUTTRESS-. 430 NHLL-NBO 19. Q e o o o Ill rv- ID &o co V) o...

Till, Larry Percy

2012-06-07T23:59:59.000Z

315

Estimates of axial leakage and void reactivity in a CANDU reactor  

SciTech Connect (OSTI)

Estimating the axial leakage in a Canada deuterium uranium (CANDU) fuel channel has been of ongoing interest because of the perceived significance of this parameter to an accurate calculation of the void effect. To verify the accuracy of such estimates, a benchmark-quality calculation of void reactivity in a standard CANDU fuel channel has been performed using the Monte Carlo code MCNP4. The result of a similar calculation for an infinite lattice of 37-element CANDU fuel bundles has been reported elsewhere. In this paper, estimates of reactivity and reactivity difference for two different arrangements of 37-element fresh CANDU fuel at both operating and voided conditions in the presence of axial leakage are discussed. It is emphasized that these results are valid for a highly idealized reactor model and cannot be directly applied to an operating reactor.

Milgram, M.S. (Atomic Energy of Canada Ltd., Ontario (Canada))

1993-01-01T23:59:59.000Z

316

NOVEL CHAMBER DESIGN FOR AN IN-VACUUM CRYO-COOLED MINI-GAP UNDULATOR.  

SciTech Connect (OSTI)

A stainless steel, Ultra-High Vacuum (UHV) chamber, featuring a large vertical rectangular port (53''W by 16''H), has been fabricated to house the one-meter magnet assembly of a newly installed undulator insertion device for beamline X-25 at the National Synchrotron Light Source. To achieve UHV, the new chamber is equipped with a differential ion pump, NEG pump, nude ion gauge, residual gas analyzer, and an all metal roughing valve. Temperature of the magnet assembly is maintained below 90 C during vacuum bake. The large rectangular port cover is sealed to the main flange of the chamber using a one-piece flat aluminum gasket and special sealing surfaces developed exclusively by Nor-Cal Products, Inc. The large flange provides easy access to the gap of the installed magnet girders for in situ magnetic measurements and shimming. Special window ports were designed into the cover and chamber for manipulation of optical micrometers external to the chamber to provide precise measurements of the in-vacuum magnet gap. The vacuum chamber assembly features independently vacuum-isolated feedthroughs that can be used for either water-or-cryogenic refrigeration-cooling of the monolithic magnet girders. This would allow for cryogenic-cooled permanent magnet operation and has been successfully tested within temperature range of +100 C to -150 C. Details of the undulator assembly for beamline X-25 is described in the paper.

HU, J.-P.; FOERSTER, C.L.; SKARITKA, J.R.; WATERMAN, D.

2006-05-24T23:59:59.000Z

317

Axial Flux, Modular, Permanent-Magnet Generator with a Toroidal Winding for Wind Turbine Applications  

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

CP-500-24996 Ÿ UC Category: 1213 CP-500-24996 Ÿ UC Category: 1213 Axial Flux, Modular, Permanent- Magnet Generator with a Toroidal Winding for Wind Turbine Applications E. Muljadi C.P. Butterfield Yih-Huei Wan National Wind Technology Center National Renewable Energy Laboratory Presented at IEEE Industry Applications Conference St. Louis, MO November 5-8, 1998 National Renewable Energy Laboratory 1617 Cole Boulevard

318

Scattering of particles by neutron stars: Time-evolutions for axial perturbations  

E-Print Network [OSTI]

The excitation of the axial quasi-normal modes of a relativistic star by scattered particles is studied by evolving the time dependent perturbation equations. This work is the first step towards the understanding of more complicated perturbative processes, like the capture or the scattering of particles by rotating stars. In addition, it may serve as a test for the results of the full nonlinear evolution of binary systems.

V. Ferrari; K. D. Kokkotas

2000-08-23T23:59:59.000Z

319

Ferromagnetic neutron stars: axial anomaly, dense neutron matter, and pionic wall  

E-Print Network [OSTI]

We show that a chiral nonlinear sigma model coupled to degenerate neutrons exhibits a ferromagnetic phase at high density. The magnetization is due to the axial anomaly acting on the parallel layers of neutral pion domain walls spontaneously formed at high density. The emergent magnetic field would reach the QCD scale ~ 10^19 [G], which suggests that the quantum anomaly can be a microscopic origin of the magnetars (highly magnetized neutron stars).

Minoru Eto; Koji Hashimoto; Tetsuo Hatsuda

2012-09-21T23:59:59.000Z

320

Fixing Two-Nucleon Weak-Axial Coupling L_{1,A} From mu-d Capture  

E-Print Network [OSTI]

We calculate the muon capture rate on the deuteron to next-to-next-to-leading order in the pionless effective field theory. The result can be used to constrain the two-nucleon isovector axial coupling L_{1,A} to +/- 2 fm^3 if the muon capture rate is measured to 2% level. From this, one can determine the neutrino-deuteron break up reactions and the pp-fusion cross section in the sun to a same level of accuracy.

Jiunn-Wei Chen; Takashi Inoue; Xiangdong Ji; Yingchuan Li

2006-01-11T23:59:59.000Z

Note: This page contains sample records for the topic "axial magma chamber" from the National Library of EnergyBeta (NLEBeta).
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321

Charmless Hadronic B Decays into Vector, Axial Vector and Tensor Final States at BaBar  

SciTech Connect (OSTI)

We present experimental measurements of branching fraction and longitudinal polarization fraction in charmless hadronic B decays into vector, axial vector and tensor final states with the final dataset of BABAR. Measurements of such kind of decays are a powerful tool both to test the Standard Model and search possible sources of new physics. In this document we present a short review of the last experimental results at BABAR concerning charmless quasi two-body decays in final states containing particles with spin 1 or spin 2 and different parities. This kind of decays has received considerable theoretical interest in the last few years and this particular attention has led to interesting experimental results at the current b-factories. In fact, the study of longitudinal polarization fraction f{sub L} in charmless B decays to vector vector (VV), vector axial-vector (VA) and axial-vector axial-vector (AA) mesons provides information on the underlying helicity structure of the decay mechanism. Naive helicity conservation arguments predict a dominant longitudinal polarization fraction f{sub L} {approx} 1 for both tree and penguin dominated decays and this pattern seems to be confirmed by tree-dominated B {yields} {rho}{rho} and B{sup +} {yields} {Omega}{rho}{sup +} decays. Other penguin dominated decays, instead, show a different behavior: the measured value of f{sub L} {approx} 0.5 in B {yields} {phi}K* decays is in contrast with naive Standard Model (SM) calculations. Several solutions have been proposed such as the introduction of non-factorizable terms and penguin-annihilation amplitudes, while other explanations invoke new physics. New modes have been investigated to shed more light on the problem.

Gandini, Paolo; /Milan U. /INFN, Milan

2012-04-06T23:59:59.000Z

322

A new nonlinear ''reconstructive'' control approach applied to the axial xenon oscillation problem in PWRs  

SciTech Connect (OSTI)

The concept of dynamic equilibrium of control in conjunction with a proportional corrector constitutes the structure of the new control technique. The controller utilizes direct measurements and model- based state estimations in the feedback loop. The method includes recovering unanticipated parametric variations or partially unknown dynamics. An application of this approach to the axial xenon oscillation problem of PWRs was considered. A two-point xenon oscillation model was used in designing the controller and testing it through simulations. 6 refs., 8 figs.

Berkan, R.C.; Upadhyaya, B.R.; Perez, R.B.; Kisner, R.A.

1989-01-01T23:59:59.000Z

323

The axial N to Delta transition form factors from Lattice QCD  

E-Print Network [OSTI]

We evaluate the N to Delta axial transition form factors in lattice QCD in the quenched theory, with two degenerate flavors of dynamical Wilson fermions and using domain wall valence fermions with staggered sea quark configurations. We predict the ratio $C_5^A(q^2)/C_3^V(q^2)$ relevant to the parity violating asymmetry and check the validity of the off-diagonal Goldberger-Treiman relation.

C. Alexandrou; Th. Leontiou; J. W. Negele; A. Tsapalis

2006-07-20T23:59:59.000Z

324

Using electron scattering to constrain the axial-vector form factor  

E-Print Network [OSTI]

We present an analysis of elastic and quasielastic parity-violating (PV) electron scattering processes. These reactions can help to constrain the weak neutral current form factors of the nucleon that play an essential role in the description of neutrino cross sections at intermediate energies. We show that combining information from the analysis of elastic and quasielastic reactions the current knowledge on the strange and axial-vector form factors can be significantly improved.

González-Jiménez, R; Donnelly, T W

2015-01-01T23:59:59.000Z

325

Torsional Alfven Waves in Solar Magnetic Flux Tubes of Axial Symmetry  

E-Print Network [OSTI]

Aims: Propagation and energy transfer of torsional Alfv\\'en waves in solar magnetic flux tubes of axial symmetry is studied. Methods: An analytical model of a solar magnetic flux tube of axial symmetry is developed by specifying a magnetic flux and deriving general analytical formulae for the equilibrium mass density and a gas pressure. The main advantage of this model is that it can be easily adopted to any axisymmetric magnetic structure. The model is used to simulate numerically the propagation of nonlinear Alfv\\'en waves in such 2D flux tubes of axial symmetry embedded in the solar atmosphere. The waves are excited by a localized pulse in the azimuthal component of velocity and launched at the top of the solar photosphere, and they propagate through the solar chromosphere, transition region, and into the solar corona. Results: The results of our numerical simulations reveal a complex scenario of twisted magnetic field lines and flows associated with torsional Alfv\\'en waves as well as energy transfer to t...

Murawski, K; Musielak, Z E; Srivastava, A K; Kraskiewicz, J

2015-01-01T23:59:59.000Z

326

Manipulating Magnetism: Ru-2(5+) Paddlewheels Devoid of Axial Interactions  

SciTech Connect (OSTI)

Variable-temperature magnetic and structural data of two pairs of diruthenium isomers, one pair having an axial ligand and the formula Ru-2(DArF)(4)Cl (where DArF is the anion of a diarylformamidine isomer and Ar = p-anisyl or m-anisyl) and the other one being essentially identical but devoid of axial ligands and having the formula [Ru-2(DArF)(4)]BF4, show that the axial ligand has a significant effect on the electronic structure of the diruthenium unit. Variable temperature crystallographic and magnetic data as well as density functional theory calculations unequivocally demonstrate the occurrence of pi interactions between the p orbitals of the chlorine ligand and the pi* orbitals in the Ru-2(5+) units. The magnetic and structural data are consistent with the existence of combined ligand sigma/metal sigma and ligand p pi/metal-d pi interactions. Electron paramagnetic resonance data show unambiguously that the unpaired electrons are in metal-based molecular orbitals.

Chiarella, Gina M [Texas A& M University; Cotton, F. A. [Texas A& M University; Murillo, Carlos A [Texas A& M University; Ventura, Karen [University of Texas at El Paso; Vilagran, Dino [University of Texas at El Paso; Wang, Xiaoping [ORNL

2014-01-01T23:59:59.000Z

327

Effect of Temporal Acquisition Parameters on the Image Quality of Ultrasound Axial Strain Time-constant Elastograms  

E-Print Network [OSTI]

constant (TC) have been developed. The axial strain TC is a parameter that is related to the viscoelastic and poroelastic behavior of tissues. Estimation of this parameter can be done using curve fitting methods. However, the effect of temporal...

Varghese, Joshua

2011-08-02T23:59:59.000Z

328

Palladium-Catalyzed Enantioselective ?-Arylation and ?-Vinylation of Oxindoles Facilitated by an Axially Chiral P-Stereogenic Ligand  

E-Print Network [OSTI]

The enantioselective ?-arylation and ?-vinylation of oxindoles catalyzed by Pd and a biarylmonophosphine ligand with both axial and phosphorus-based chirogenicity is reported. The resultant quaternary carbon stereocenters ...

Taylor, Alexander M.

329

Experiments and analysis for an axially heterogeneous liquid-metal reactor assembly at the zero-power physics reactor  

SciTech Connect (OSTI)

Experiments in zero-power physics reactor 17 provided physics data for a full-scale axially heterogeneous 650-MW(electric) liquid-metal reactor. Measurements and analysis are reported for control rod worths, reaction rate distributions, gamma dose distributions, sodium void worths, and criticality. Agreement between measurement and calculation is generally satisfactory, but the axial heterogeneity did introduce analytical complications. Design-level calculation methods gave somewhat worse agreement with measurement than in previous homogeneous or radially heterogeneous assemblies.

Brumbach, S.B.; Collins, P.J. (Argonne National Lab., Idaho Falls, ID (USA))

1989-11-01T23:59:59.000Z

330

Drillers hit Hawaiian magma  

Science Journals Connector (OSTI)

... A geothermal drill rig in Hawaii has for the first time tapped into intensely hot, granite- ... the Big Island of Hawaii. They hope to turn the site – currently an operating geothermal development – into an observatory for scientific studies. ...

Rex Dalton

2008-12-17T23:59:59.000Z

331

A study of the design procedure and the performance characteristics of axial exhaust fans  

E-Print Network [OSTI]

of the requirements for the degxee of %%STER OF SCIENCE IN NECHM3EEL ENGINEERIMG August, 19/9 COBTEEITS Intoroduct'o9. on o e e ~ ~ ~ ~ ~ e ~ e ~ ~ ~ ~ ~ 1 Ia Derivation of Fan Lass ~ ~ ~ ~ ~ ~ ~ ~ ~ 2 XI Description of Test Apparatus . . . . . ~. . . 7 XII... by s reversible electric motor operated by a reversing motor control switch, which is conveniently located near the Inclined manometer connected, to the pitot tube which measures the static pressure inside the plenum chamber. The followiug equipment composes...

Barker, Gilbert Hamilton

2012-06-07T23:59:59.000Z

332

Final report for NIF chamber dynamics studies, final rept (May 1997), Subcontract No. B291847  

SciTech Connect (OSTI)

The National Ignition Facility (NIF), a 1.8 MJ, 192 laser beam facility, will have anticipated fusion yields of up to 20 MJ from D-T pellets encased in a gold hohlraum target. The energy emitted from the target in the form of x rays, neutrons, target debris kinetic energy, and target shrapnel will be contained in a 5 m. radius spherical target chamber. Various diagnostics will be stationed around the target at varying distances from the target. During each shot, the target will emit x rays that will vaporize nearby target facing surfaces including those of the diagnostics, the target positioner, and other chamber structures. This ablated vapor will be transported throughout the chamber, and will eventually condense and deposit on surfaces in the chamber, including the final optics debris shields. The research at the University of California at Berkeley relates primarily to the NIF chamber dynamics. The key design issues are the ablation of the chamber structures, transport of the vapor through the chamber and the condensation or deposition processes of those vaporized materials. An understanding of these processes is essential in developing a concept for protecting the final optics debris shields from an excessive coating (> 10 {Angstrom}) of target debris and ablated material, thereby prolonging their lifetime between change- outs. At Berkeley, we have studied the physical issues of the ablation process and the effects of varying materials, the condensation process of the vaporized material, and design schemes that can lower the threat posed to the debris shields by these processes. In addition to the work described briefly above, we performed extensive analysis of the target-chamber thermal response to in- chamber CO{sub 2} Cleaning and of work performed to model the behavior of silica vapor. The work completed this year has been published in several papers and a dissertation [1-6]. This report provides a summary of the work completed this year, as well as copies fo presentation materials that have not been published elsewhere. In particular, the Appendix contains copies of presentations made on CO{sub 2} cleaning that are not available elsewhere.

Peterson, P.F.; Jin, H.; Scott, J.M. [University of California, Berkeley (United States)

1997-07-01T23:59:59.000Z

333

April 10, 2002 A. R. Raffray, et al., Dynamic Chamber Armor Behavior in IFE and MFE 1 Dynamic Chamber Armor Behavior in IFE and MFE  

E-Print Network [OSTI]

Limiter 0.5 (~8 for ~100s) 30000 (5000) Baffle 3 3000-10000 Divertor target ~10 3000-10000 #12;April 10/m2 Affected area 5-10 m2 A few m2 ~10 m2 Chamber wall (R~5-10 m) Location Surface (near divertor ms ~ 1-3 µs Max. Temperature Melting/ sublimation Melting/ sublimation Melting/ sublimation ~ 2000-3000

Raffray, A. René

334

U.S. Chamber of Commerce Biofuels Dialogue Series: Outlook for an Emerging  

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

Commerce Biofuels Dialogue Series: Outlook for an Commerce Biofuels Dialogue Series: Outlook for an Emerging Global Biofuels Market U.S. Chamber of Commerce Biofuels Dialogue Series: Outlook for an Emerging Global Biofuels Market January 29, 2008 - 10:53am Addthis Remarks as Prepared For Delivery by Secretary Bodman Thank you very much, Bruce, for that kind introduction. My thanks also to Tom Donahue and the leadership of the Chamber for inviting me to be with you today. I was quite pleased to hear that the Chamber was sponsoring this event. As anyone who knows me - or has heard me speak recently - can tell you, the biofuels industry is a favorite topic of mine. In my view, advanced biofuels offer tremendous promise for helping our nation to bring about a new energy future-one that is cleaner, more sustainable, more affordable,

335

OSTIblog Posts by Kathy Chambers | OSTI, US Dept of Energy, Office of  

Office of Scientific and Technical Information (OSTI)

Kathy Chambers Kathy Chambers Kathy Chambers's picture Senior STI Specialist, Information International Associates, Inc. Enjoy the benefits of LED lighting Source: http://www.flickr.com/photos/uscapitol/6309229615/in/photostream/ Published on Dec 30, 2013 Every day we are bombarded with advertisements in every form and format telling us that our lives will be improved if we buy a particular product because it will save us money, reduce our work effort, save us energy, or benefit the environment. We are justifiably skeptical because we know from experience that if something sounds too good to be true, usually it is. Light-emitting diode (LED) lighting is one of the exceptions. LEDs benefits are so powerful that they seem too good to be true; however, they actually do save us money, reduce our work effort, save us energy and benefit our environment.

336

The off-shell axial anomaly via the {gamma}*{pi}{sup 0} {yields} {gamma} transition  

SciTech Connect (OSTI)

The {gamma}*{pi}{sup 0} {yields} {gamma} form factor, including the extension off the pion mass-shell, is obtained from a generalized impulse approximation within a QCD-based model field theory known to provide an excellent description of the pion charge form factor. This approach implements dressing of the vertex functions and propagators consistent with dynamical chiral symmetry breaking, gauge invariance, quark confinement and perturbative QCD. Soft nonperturbative behavior, dictated by the axial anomaly, is found to evolve to the perturbative QCD limit only for Q{sup 2} {ge} 20 GeV{sup 2}.

Frank, M.R. [Univ. of Washington, Seattle, WA (United States). Institute for Nuclear Theory; Mitchell, K.L.; Tandy, P.C. [Kent State Univ., OH (United States); Roberts, C.D. [Argonne National Lab., IL (United States)

1995-01-01T23:59:59.000Z

337

Statistical and risk analysis for the measured and predicted axial response of 100 piles  

E-Print Network [OSTI]

of Committee) cu. Har y M. Coyl (Member) J rey D. Hart (Member) Donald McDonald (Head of Department) May 1986 ABSTRACT Statistical and Risk Analysis for the Measured and Predicted Axial Response of 100 Piles (December 1985) Dario Perdomo, B. S... encouragement and financial support. Sincere thanks are expressed to Dr. Jean-Louis Briaud and Nr. Larry Tucker i'or their guidance and advice throughout the course of this research. The assistance of Dr. Harry Coyle and Dr. Jeffrey Hart are also...

Perdomo, Dario

1986-01-01T23:59:59.000Z

338

Modular axial-flux permanent-magnet motor for ship propulsion drives  

SciTech Connect (OSTI)

Original features such as compactness and lightness make slotless axial-flux permanent-magnet machines (AFPMs) eligible for application in large power motor drives devoted to the direct drive of ship propellers. This paper discusses characteristics of AFPMs designed for application in marine propulsion, and machine performances such as efficiency, weight and torque density are evaluated for a comparison with those of conventional synchronous machines. A newly-conceived modular arrangement of the machine stator winding is proposed and experimental results taken from a small-size machine prototype are finally shown.

Caricchi, F.; Crescimbini, F.; Honorati, O.

1999-09-01T23:59:59.000Z

339

Parity-Violating Electron Deuteron Scattering and the Proton's Neutral Weak Axial Vector Form Factor  

SciTech Connect (OSTI)

We report on a new measurement of the parity-violating asymmetry in quasielastic electron scattering from the deuteron at backward angles at Q2 = 0.038 (GeV/c)2. This quantity provides a determination of the neutral weak axial vector form factor of the nucleon, which can potentially receive large electroweak corrections. The measured asymmetry A = z3.51±0.57 (stat)±0.58 (syst) ppm is consistent with theoretical predictions. We also report on updated results of the previous experiment at Q2 = 0.091 (GeV/c)2, which are also consistent with theoretical predictions.

Ito, Takeyasu; Averett, Todd; Barkhuff, David; Batigne, Guillaume; Beck, Douglas; Beise, Elizabeth; Blake, A.; Breuer, Herbert; Carr, Robert; Clasie, Benjamin; Covrig, Silviu; Danagoulian, Areg; Dodson, George; Dow, Karen; Dutta, Dipangkar; Farkhondeh, Manouchehr; Filippone, Bradley; FRANKLIN, W.; Furget, Christophe; Gao, Haiyan; Gao, Juncai; Gustafsson, Kenneth; Hannelius, Lars; Hasty, R.; Allen, Alice; Herda, M.C.; Jones, CE; King, Paul; Korsch, Wolfgang; Kowalski, Stanley; Kox, Serge; Kramer, Kevin; Lee, P.; Liu, Jinghua; Martin, Jeffery; McKeown, Robert; Mueller, B.; Pitt, Mark; Plaster, Bradley; Quemener, Gilles; Real, Jean-Sebastien; Ritter, J.; Roche, Julie; Savu, V.; Schiavilla, Rocco; Seely, Charles; Spayde, Damon; Suleiman, Riad; Taylor, S.; Tieulent, Raphael; Tipton, Bryan; Tsentalovich, E.; Wells, Steven; Yang, Bin; Yuan, Jing; Yun, Junho; Zwart, Townsend

2004-03-01T23:59:59.000Z

340

Axial thermal medium delivery tubes and retention plates for a gas turbine rotor  

DOE Patents [OSTI]

In a multi-stage turbine rotor, tubes are disposed in openings adjacent the rotor rim for flowing a thermal medium to rotor buckets and returning spent thermal medium. The tubes have axially spaced lands of predetermined wall thickness with thin-walled tube sections between the lands and of increasing thickness from the forward to the aft ends of the tubes. A pair of retention plates are carried on the aft end face of the aft wheel and straddle the tube and engage against a shoulder on the tube to preclude displacement of the tube in an aft direction.

Mashey, Thomas Charles (Coxsackie, NY)

2002-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "axial magma chamber" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Torque ripple minimization of axial laminations switched reluctance motor provided with digital lead controller  

Science Journals Connector (OSTI)

The switched reluctance motor (SRM) has great potential as an adjustable speed application due to its outstanding merits. One of the major problems is torque ripple which causes increased undesirable acoustic noise and possibly speed ripple. This paper investigates the application of a digital lead controller to the axial laminations switched reluctance motor (ALSRM) for the purpose of minimizing its torque ripples. The dynamic response of the ALSRM with the proposed controller is analyzed. The effectiveness of the proposed digital lead controller is then compared with that of the conventional PI controller.

Hany M. Hasanien; S.M. Muyeen; Junji Tamura

2010-01-01T23:59:59.000Z

342

Sigma-terms and axial charges for hyperons and charmed baryons  

E-Print Network [OSTI]

We present results for the $\\sigma$-terms and axial charges for various hyperons and charmed baryons using $N_f=2+1+1$ twisted mass fermions. For the computation of the three-point function we use the fixed current method. For one of the $N_f=2+1+1$ ensembles with pion mass of 373 MeV we compare the results of the fixed current method with those obtained with a stochastic method for computing the all-to-all propagator involved in the evaluation of the three point functions.

C. Alexandrou; K. Hadjiyiannakou; K. Jansen; Ch. Kallidonis

2014-04-25T23:59:59.000Z

343

Power density axial oscillations induced by Xenon dynamics: Parameter identification via genetic algorithms  

Science Journals Connector (OSTI)

In this paper we describe the axial flux oscillations in \\{PWRs\\} by means of the Onega and Kisner model (1978), a two-point xenon oscillation model based on the one-group, one-dimensional neutron diffusion equation with nonlinear power reactivity feedback and on the nonlinear xenon and iodine balance equations. We investigate the feasibility of using genetic algorithms for estimating the effective nuclear parameters involved. This approach has the advantage of allowing the periodic re-estimation of the effective parameter values pertaining to each reactor on the basis of its recent history. By so doing, other effects, such as the burn up, are automatically taken into account.

M. Marseguerra; E. Zio; G. Torri

2003-01-01T23:59:59.000Z

344

Partially Conserved Axial-Vector Current Restrictions on Pion Photoproduction and Electroproduction Amplitudes  

Science Journals Connector (OSTI)

We discuss numerically the restrictions imposed by the partially conserved axial-vector current (PCAC) on the pion photoproduction amplitude V1(+)(0) and on the pion electroproduction amplitude V6(-)(0). We find that the magnetic-dipole dominance and the narrow-resonance approximations are unreliable. The nonresonant s waves make an important contribution to V1(+)(0), and we find that the PCAC prediction for this amplitude is reasonably well satisfied. The electric and longitudinal multipoles appear to make a much bigger contribution to V6(-)(0) than does the magnetic dipole M1+, which is strongly suppressed by the kinematics.

Stephen L. Adler and Frederick J. Gilman

1966-12-23T23:59:59.000Z

345

Small-Chamber Measurements of Chemical-Specific Emission Factors for  

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

Small-Chamber Measurements of Chemical-Specific Emission Factors for Small-Chamber Measurements of Chemical-Specific Emission Factors for Drywall Title Small-Chamber Measurements of Chemical-Specific Emission Factors for Drywall Publication Type Report Year of Publication 2010 Authors Maddalena, Randy L., Marion L. Russell, Moya Melody, and Michael G. Apte Publisher Lawrence Berkeley National Laboratory City Berkeley Abstract Imported drywall installed in U.S. homes is suspected of being a source of odorous and potentially corrosive indoor pollutants. To support an investigation of those building materials by the Consumer Products Safety Commission (CPSC), Lawrence Berkeley National Laboratory (LBNL) measured chemical-specific emission factors for 30 samples of drywall materials. Emission factors are reported for 75 chemicals and 30 different drywall samples encompassing both domestic and imported stock and incorporating natural, synthetic, or mixed gypsum core material. CPSC supplied all drywall materials. First the drywall samples were isolated and conditioned in dedicated chambers, then they were transferred to small chambers where emission testing was performed. Four sampling and analysis methods were utilized to assess (1) volatile organic compounds, (2) low molecular weight carbonyls, (3) volatile sulfur compounds, and (4) reactive sulfur gases. LBNL developed a new method that combines the use of solid phase microextraction (SPME) with small emission chambers to measure the reactive sulfur gases, then extended that technique to measure the full suite of volatile sulfur compounds. The testing procedure and analysis methods are described in detail herein. Emission factors were measured under a single set of controlled environmental conditions. The results are compared graphically for each method and in detailed tables for use in estimating indoor exposure concentrations

346

Investigation of long drift chambers for a nucleon-decay detector  

SciTech Connect (OSTI)

The use of long drift chambers for a nucleon-decay detector is discussed as a means of achieving a detector with very fine tracking, but with a modest number of readout channels. Strategies for reducing the attenuation of drifting electrons are considered, particularly the necessity of shaping the electric field to reduce the effects of diffusion and of nearby grounded conductors. Measured results are presented for a chamber with 1 cm drift gap and 50 cm maximum drift distance. The measured attenuation is 12%.

Price, L.E.; Dawson, J.; Ayres, D.; Denis, R.S.

1981-01-01T23:59:59.000Z

347

Construction and test of high precision drift-tube (sMDT) chambers for the ATLAS muon spectrometer  

E-Print Network [OSTI]

For the upgrade of the ATLAS muon spectrometer in March 2014 new muon tracking chambers (sMDT) with drift-tubes of 15 mm diameter, half of the value of the standard ATLAS Monitored Drift-Tubes (MDT) chambers, and 10~$\\mu$m positioning accuracy of the sense wires have been constructed. The new chambers are designed to be fully compatible with the present ATLAS services but, with respect to the previously installed ATLAS MDT chambers, they are assembled in a more compact geometry and they deploy two additional tube layers that provide redundant rack information. The chambers are composed of 8 layers of in total 624 aluminium drift-tubes. The assembly of a chamber is completed within a week. A semi-automatized production line is used for the assembly of the drift-tubes prior to the chamber assembly. The production procedures and the quality control tests of the single components and of the complete chambers will be discussed. The wire position in the completed chambers have been measured by using a coordinate me...

Nowak, Sebastian; Kroha, Hubert; Schwegler, Philipp; Sforza, Federico

2014-01-01T23:59:59.000Z

348

Construction and test of high precision drift-tube (sMDT) chambers for the ATLAS muon spectrometer  

E-Print Network [OSTI]

For the upgrade of the ATLAS muon spectrometer in March 2014 new muon tracking chambers (sMDT) with drift-tubes of 15 mm diameter, half of the value of the standard ATLAS Monitored Drift-Tubes (MDT) chambers, and 10~$\\mu$m positioning accuracy of the sense wires have been constructed. The new chambers are designed to be fully compatible with the present ATLAS services but, with respect to the previously installed ATLAS MDT chambers, they are assembled in a more compact geometry and they deploy two additional tube layers that provide redundant rack information. The chambers are composed of 8 layers of in total 624 aluminium drift-tubes. The assembly of a chamber is completed within a week. A semi-automatized production line is used for the assembly of the drift-tubes prior to the chamber assembly. The production procedures and the quality control tests of the single components and of the complete chambers will be discussed. The wire position in the completed chambers have been measured by using a coordinate measuring machine.

Sebastian Nowak; Oliver Korner; Hubert Kroha; Philipp Schwegler; Federico Sforza

2014-07-01T23:59:59.000Z

349

Multi-gap Resistive Plate Chambers as a Time-of-Flight System for the PHENIX Experiment  

SciTech Connect (OSTI)

In this project a Time-of-Flight detector based on multi-gap resistive plate chambers was built and installed for the PHENIX experiment at RHIC.

Velkovska, Julia [Vanderbilt University] [Vanderbilt University

2013-12-08T23:59:59.000Z

350

Dynamics of neutralizing electrons during the focusing of intense heavy ions beams inside a heavy fusion reactor chamber  

E-Print Network [OSTI]

beams inside a heavy ion fusion reactor chamber * Agustin F.efficiency of a Heavy Ion Fusion reactor heavily depends on

Lifschitz, Agustin F.; Maynard, Gilles; Vay, Jean-Luc; Lenglet, Andrian

2006-01-01T23:59:59.000Z

351

Broken axial symmetry as essential feature to predict radiative capture in heavy nuclei  

E-Print Network [OSTI]

Cross sections for neutron capture in the range of unresolved resonances are predicted for more than 140 spin-0 target nuclei with A > 50. Allowing the breaking of spherical and axial symmetry in nearly all these nuclei a combined parameterization for both, level density and photon strength is obtained which employs a surprisingly small number of parameters only. The strength functions used are based on a global fit to IVGDR shapes by the sum of three Lorentzians. They are based on theoretical predictions for the A-dependence of pole energies and spreading widths and add up to the TRK sum rule. For the small spins reached by capture resonance spacings are well described by a level density parameter close to the nuclear matter value; a significant collective enhancement is apparent due to the deviation from axial symmetry. Reliable predictions for compound nuclear reactions also outside the valley of stability (as important for nuclear astrophysics and for the transmutation of nuclear waste) are expected to result from the global parameterization presented.

Eckart Grosse; Arnd R. Junghans; Ralph Massarczyk

2015-01-14T23:59:59.000Z

352

Measuring the axial form factor of {sup 3}He using weak capture of polarized electrons  

SciTech Connect (OSTI)

A low energy, high intensity polarized electron beam could enable the extraction of the A=3 weak axial form factors F{sub A} using the reaction ?e+{sup 3}He?{sup 3}H+?. These form factors have never been measured before. We discuss the feasibility of such an experiment using a small toroidal magnet and a radial low energy recoil detector to tag the recoil tritons. A moderately high intensity polarized electron beam (>500 ?A) with beam energies between 50 - 150 MeV is necessary for the cross section measurement and to provides a free clean measurement of the background. Moreover, in addition to the cross section, by measuring the electron spin and recoil triton correlation coefficient it may be possible to search for second class currents and to extract the ratio of the axial to the vector form factor of the nucleon. Such novel electron scattering based measurements would have a completely different set of systematic uncertainties compared to polarized neutron beta decay, neutrino scattering and muon capture experiments which are typically used to extract the weak form-factors.

Dutta, D. [Mississippi State University, Mississippi State, MS 39762 (United States)

2013-11-07T23:59:59.000Z

353

Clean measurements of the nucleon axial-vector and free-neutron magnetic form factors  

SciTech Connect (OSTI)

We discuss the feasibility of a weak charged current experiment using a low energy electron beam. A first goal is to measure the Q^2 dependence of the axial-vector form factor g_a(Q^2). It can be measured model-independently and as robustly as for electromagnetic form factors from typical electron scattering experiments, in contrast to the methods used so far to measure g_a(Q^2). If g_a(Q^2) follows a dipole form, the axial mass can be extracted with a better accuracy than the world data altogether. The most important detection equipment would be a segmented neutron detector with good momentum and angular resolution that is symmetric about the beam direction, and covers a moderate angular range. A high intensity beam (100 uA) is necessary. Beam polarization is highly desirable as it provides a clean measurement of the backgrounds. Beam energies between 70 and 110 MeV are ideal. This range would provide a Q^2 mapping of g_a between 0.01

Deur, Alexandre P. [JLAB

2013-11-01T23:59:59.000Z

354

Broken axial symmetry as essential feature to predict radiative capture in heavy nuclei  

E-Print Network [OSTI]

Cross sections for neutron capture in the range of unresolved resonances are predicted for more than 140 spin-0 target nuclei with A > 50. Allowing the breaking of spherical and axial symmetry in nearly all these nuclei a combined parameterization for both, level density and photon strength is obtained which employs a surprisingly small number of parameters only. The strength functions used are based on a global fit to IVGDR shapes by the sum of three Lorentzians. They are based on theoretical predictions for the A-dependence of pole energies and spreading widths and add up to the TRK sum rule. For the small spins reached by capture resonance spacings are well described by a level density parameter close to the nuclear matter value; a significant collective enhancement is apparent due to the deviation from axial symmetry. Reliable predictions for compound nuclear reactions also outside the valley of stability (as important for nuclear astrophysics and for the transmutation of nuclear waste) are expected to result from the global parameterization presented.

Eckart Grosse; Arnd R. Junghans; Ralph Massarczyk

2014-09-06T23:59:59.000Z

355

Broken axial symmetry as essential feature to predict radiative capture in heavy nuclei  

E-Print Network [OSTI]

Cross sections for neutron capture in the range of unresolved resonances are predicted for more than 140 spin-0 target nuclei with A > 50. Allowing the breaking of spherical and axial symmetry in nearly all these nuclei a combined parameterization for both, level density and photon strength is obtained which employs a surprisingly small number of parameters only. The strength functions used are based on a global fit to IVGDR shapes by the sum of three Lorentzians. They are based on theoretical predictions for the A-dependence of pole energies and spreading widths and add up to the TRK sum rule. For the small spins reached by capture resonance spacings are well described by a level density parameter close to the nuclear matter value; a significant collective enhancement is apparent due to the deviation from axial symmetry. Reliable predictions for compound nuclear reactions also outside the valley of stability (as important for nuclear astrophysics and for the transmutation of nuclear waste) are expected to re...

Grosse, Eckart; Massarczyk, Ralph

2014-01-01T23:59:59.000Z

356

Experiments with a pressure-driven Stirling refrigerator with flexible chambers  

Science Journals Connector (OSTI)

We report on the design and experimental testing of a Stirling refrigerator that uses air as the working fluid and where the conventional piston-cylinder assemblies are replaced by pressure-driven flexible chambers. The two chambers are periodically compressed by pneumatic actuators resulting in airflow through the regenerator and in a net temperature difference between the chambers. An experimental setup is used to investigate the performance of the refrigerator under different operating conditions with particular attention to actuation frequencies driving pressure differences and phase angles between the two inputs. The time constant of the temperature difference between the two chambers is determined and the temperature difference is measured as a function of the system parameters. The results of several tests conducted under different operating conditions show that the refrigerating effect is very robust and allows good performance even for modulated inputs. The frequency response is radically different from that of a traditional motion-driven device. This work suggests that mechanical to thermal energy conversion devices based on this principle can be successfully powered by human motion.

Patrick McFarlane; Jonathan Suire; Mihir Sen

2014-01-01T23:59:59.000Z

357

IFE THICK LIQUID WALL CHAMBER DYNAMICS: GOVERNING MECHANISMS AND MODELING AND  

E-Print Network [OSTI]

fluid! led to the HYLIFE-II design.7 The most recent integrated design based on a TLW chamber, a heavy guide future analysis and research and devel- opment efforts. KEYWORDS: inertial fusion energy, liquid to the 1970s ~Refs. 1, 2, and 3!. The first detailed conceptual design work was carried out at Lawrence

Raffray, A. René

358

Modelling of e-cloud build-up in grooved vacuum chambers usingPOSINST  

SciTech Connect (OSTI)

Use of grooved vacuum chambers have been suggested as a wayto limitelectron cloud accumulation in the ILC-DR. We report onsimulations carried out using an augmented version of POSINST, accountingfor e-cloud dynamics in the presence of grooves, and make contact withprevious estimates of an effective secondary electron yield for groovedsurfaces.

Venturini, Marco; Celata, C.; Furman, Miguel; Vay, Jean-Luc; Pivi, Mauro

2007-06-29T23:59:59.000Z

359

Numerical simulation of detonation processes in a variable cross-section chamber  

E-Print Network [OSTI]

Numerical simulation of detonation processes in a variable cross-section chamber H Y Fan and F K Lu for publication on 8 November 2007. DOI: 10.1243/09544100JAERO272 Abstract: The detonation processes occurring mechanism is used. Two detonation cases are simulated, corresponding to initiation from the closed, left end

Texas at Arlington, University of

360

Calculating Radiative Heat Transfer in an Axisymmetric Closed Chamber: An Application  

E-Print Network [OSTI]

Calculating Radiative Heat Transfer in an Axisymmetric Closed Chamber: An Application to Crystal University of New York at Stony Brook Stony Brook N.Y. 11794 ABSTRACT Radiative heat transfer plays simulating radiative heat transfer in the crystal and in the region above the melt containing gas under

New York at Stoney Brook, State University of

Note: This page contains sample records for the topic "axial magma chamber" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Design and optimization of 6li neutron-capture pulse mode ion chamber  

E-Print Network [OSTI]

The purpose of this research is to design and optimize the performance of a unique, inexpensive 6Li neutron-capture pulse-mode ion chamber (LiPMIC) for neutron detection that overcomes the fill-gas contamination stemming from outgas of detector...

Chung, Kiwhan

2009-05-15T23:59:59.000Z

362

October 24, 2001 1. Remaining Action Items on Dry Chamber Wall  

E-Print Network [OSTI]

of Simplified Assumption Used to Estimate Temporal Distribution of Energy Depositions Photons Debris Ions Time10ns 0.2µs 1µs 2.5µs Fast Ions Energy Deposition Temporal Distribution of Energy Depositions from Ions for Direct Drive Spectra and Chamber Radius of 6.5 m Simplified Temporal Distribution of Energy Depositions

Raffray, A. René

363

First limit from a surface run of a 10 liter Dark Matter Time Projection Chamber  

E-Print Network [OSTI]

A 10 liter prototype Dark Matter Time Projection Chamber (DMTPC) is operated on the surface of the earth at 75 Torr using carbon-tetrafluoride (CF4) as a target material to obtain a 24.57 gram-day exposure. A limit is set ...

Caldwell, Thomas S., Jr

2009-01-01T23:59:59.000Z

364

Anode supported single chamber solid oxide fuel cells operating in exhaust gases of thermal engine  

E-Print Network [OSTI]

Anode supported single chamber solid oxide fuel cells operating in exhaust gases of thermal engine fuel cells are usually described as devices able to convert chemical energy into electrical energy. Conventional solid oxide fuel cells are separated into two compartments containing each electrode split

Boyer, Edmond

365

A Diffusion Cloud Chamber Study of Very Slow Mesons. II. Beta Decay of the Muon  

DOE R&D Accomplishments [OSTI]

The spectrum of electrons arising from the decay of the negative mu meson has been determined. The muons are arrested in the gas of a high pressure hydrogen filled diffusion cloud chamber. The momenta of the decay electrons are determined from their curvature in a magnetic field of 7750 gauss. The spectrum of 415 electrons has been analyzed according to the theory of Michel.

Lederman, L. M.; Sargent, C. P.; Rinehart, M.; Rogers, K.

1955-03-00T23:59:59.000Z

366

A model for the emergence of pillars, walls and royal chambers in termite nests  

E-Print Network [OSTI]

A model for the emergence of pillars, walls and royal chambers in termite nests Eric Bonabeau1, 31062 Toulouse Ce¨ dex, France A simple model of the emergence of pillars in termite nests by Deneubourg construction modi¢es current building conditions, we hypothesize that nest complexity can result from

Theraulaz, Guy

367

Automation of Evaporation Chamber for International Space Station CONTROL ALGORITHMFUNNEL VIEW  

E-Print Network [OSTI]

Automation of Evaporation Chamber for International Space Station MOTIVATION DIAL CONTROL are as shown. The direction of fluid/gas flow is indicated by the arrows. Our team would like to acknowledge the Canadian Space Agency and U of T Thermal Kinetic Lab for their contributions to the project. Gas Fluid

368

arXiv:astro-ph/0503398v117Mar2005 Development of Bubble Chambers With Enhanced Stability and Sensitivity to  

E-Print Network [OSTI]

arXiv:astro-ph/0503398v117Mar2005 Development of Bubble Chambers With Enhanced Stability Fermi National Accelerator Laboratory, Batavia, IL, USA The viability of using a Bubble Chamber for rare stability in such a detector are described. Results from prototype trials indicate that sensitivity to low

Collar, Juan I.

369

Natural Circulation and Linear Stability Analysis for Liquid-Metal Reactors with the Effect of Fluid Axial Conduction  

SciTech Connect (OSTI)

The effect of fluid axial thermal conduction on one-dimensional liquid metal natural circulation and its linear stability was performed through nondimensional analysis, steady-state assessment, and linear perturbation evaluation. The Nyquist criterion and a root-search method were employed to find the linear stability boundary of both forward and backward circulations. The study provided a relatively complete analysis method for one-dimensional natural circulation problems with the consideration of fluid axial heat conduction. The results suggest that fluid axial heat conduction in a natural circulation loop should be considered only when the modified Peclet number is {approx}1 or less, which is significantly smaller than the practical value of a lead liquid metal-cooled reactor.

Piyush Sabharwall; Qiao Wu; James J. Sienicki

2012-06-01T23:59:59.000Z

370

Parameter study on the static strength of axially loaded multiplanar XX-joints in rectangular hollow sections  

SciTech Connect (OSTI)

This paper presents the results of a numerical parameter study on the static behavior of axially loaded multiplanar XX-joints. It forms a part of a research project on multiplanar connections between rectangular hollow sections in which various geometrical joint configurations and load combinations are being investigated. The most important geometrical joint parameters including the brace width over chord width ratio and the chord width over chord thickness ratio have been studied. For each multiplanar joint with a specific set of geometrical joint parameters, five load ratios between the axial loads on the out-of-plane and the in-plane braces are included, so that both multiplanar geometrical stiffening effects and multiplanar load effects can be determined numerically. A set of ultimate load capacity formulae for axially loaded multiplanar XX-joints has been recommended.

Yu, Y.; Wardenier, J. [Delft Univ. of Technology (Netherlands)

1996-12-01T23:59:59.000Z

371

Time-synchronized continuous wave laser-induced fluorescence axial velocity measurements in a diverging cusped field thruster  

Science Journals Connector (OSTI)

Measurements are presented of time-synchronized axial ion velocities at three positions in the discharge channel and plume of a diverging cusped field thruster operating on xenon. Xenon axial ion velocities for the thruster are derived from laser-induced fluorescence measurements of the 5d[4]7/2–6p[3]5/2 xenon ion excited state transition centred at ? = 834.72 nm. The thruster is operated in a high-current mode, where the anode discharge current is shown to oscillate quasi-periodically. A sample-hold scheme is implemented to correlate ion velocities to phases along the current cycle. These time-synchronized measurements show that median axial ion velocities decrease as discharge current increases, and that the widths of ion velocity distributions increase with increases in discharge current for positions at the exit plane and outside the thruster channel.

N A MacDonald; M A Cappelli; W A Hargus Jr

2014-01-01T23:59:59.000Z

372

Plate Fin Heat Exchanger Model with Axial Conduction and Variable Properties  

SciTech Connect (OSTI)

Future superconducting radio frequency (SRF) cavities, as part of Project X at Fermilab, will be cooled to superfluid helium temperatures by a cryogenic distribution system supplying cold supercritical helium. To reduce vapor fraction during the final Joule-Thomson (J-T) expansion into the superfluid helium cooling bath, counter-flow, plate-fin heat exchangers will be utilized. Due to their compact size and ease of fabrication, plate-fin heat exchangers are an effective option. However, the design of compact and high-effectiveness cryogenic heat exchangers operating at liquid helium temperatures requires consideration of axial heat conduction along the direction of flow, in addition to variable fluid properties. Here we present a numerical model that includes the effects of axial conduction and variable properties for a plate fin heat exchanger. The model is used to guide design decisions on heat exchanger material choice and geometry. In addition, the J-T expansion process is modeled with the heat exchanger to analyze the effect of heat load and cryogenic supply parameters. A numerical model that includes the effects of axial conduction and variable properties for a plate fin heat exchanger was developed and the effect of various design parameters on overall heat exchanger size was investigated. It was found that highly conductive metals should be avoided in the design of compact JT heat exchangers. For the geometry considered, the optimal conductivity is around 3.5 W/m-K and can range from 0.3-10 W/m-K without a large loss in performance. The model was implemented with an isenthalpic expansion process. Increasing the cold side inlet temperature from 2K to 2.2 K decreased the liquid fraction from 0.856 to 0.839 which corresponds to a 0.12 g/s increase in supercritical helium supply needed to maintain liquid level in the cooling bath. Lastly, it was found that the effectiveness increased when the heat load was below the design value. Therefore, the heat exchanger should be sized on the high end of the required heat load.

Hansen, B.J.; White, M.J.; Klebaner, A.; /Fermilab

2011-06-10T23:59:59.000Z

373

Monte Carlo calculations for reference dosimetry of electron beams with the PTW Roos and NE2571 ion chambers  

SciTech Connect (OSTI)

Purpose: To investigate recommendations for reference dosimetry of electron beams and gradient effects for the NE2571 chamber and to provide beam quality conversion factors using Monte Carlo simulations of the PTW Roos and NE2571 ion chambers. Methods: The EGSnrc code system is used to calculate the absorbed dose-to-water and the dose to the gas in fully modeled ion chambers as a function of depth in water. Electron beams are modeled using realistic accelerator simulations as well as beams modeled as collimated point sources from realistic electron beam spectra or monoenergetic electrons. Beam quality conversion factors are calculated with ratios of the doses to water and to the air in the ion chamber in electron beams and a cobalt-60 reference field. The overall ion chamber correction factor is studied using calculations of water-to-air stopping power ratios. Results: The use of an effective point of measurement shift of 1.55 mm from the front face of the PTW Roos chamber, which places the point of measurement inside the chamber cavity, minimizes the difference betweenR{sub 50}, the beam quality specifier, calculated from chamber simulations compared to that obtained using depth-dose calculations in water. A similar shift minimizes the variation of the overall ion chamber correction factor with depth to the practical range and reduces the root-mean-square deviation of a fit to calculated beam quality conversion factors at the reference depth as a function of R{sub 50}. Similarly, an upstream shift of 0.34 r{sub cav} allows a more accurate determination of R{sub 50} from NE2571 chamber calculations and reduces the variation of the overall ion chamber correction factor with depth. The determination of the gradient correction using a shift of 0.22 r{sub cav} optimizes the root-mean-square deviation of a fit to calculated beam quality conversion factors if all beams investigated are considered. However, if only clinical beams are considered, a good fit to results for beam quality conversion factors is obtained without explicitly correcting for gradient effects. The inadequacy of R{sub 50} to uniquely specify beam quality for the accurate selection of k{sub Q} factors is discussed. Systematic uncertainties in beam quality conversion factors are analyzed for the NE2571 chamber and amount to between 0.4% and 1.2% depending on assumptions used. Conclusions: The calculated beam quality conversion factors for the PTW Roos chamber obtained here are in good agreement with literature data. These results characterize the use of an NE2571 ion chamber for reference dosimetry of electron beams even in low-energy beams.

Muir, B. R., E-mail: bmuir@physics.carleton.ca; Rogers, D. W. O., E-mail: drogers@physics.carleton.ca [Physics Department, Carleton Laboratory for Radiotherapy Physics, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6 (Canada)] [Physics Department, Carleton Laboratory for Radiotherapy Physics, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6 (Canada)

2013-12-15T23:59:59.000Z

374

LS-266 OPTIMIZATION OF FOUR-BUTTON BEAM POSITION MONITOR CONFIGURATION FOR SMALL-GAP VACUUM CHAMBERS  

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

LS-266 LS-266 OPTIMIZATION OF FOUR-BUTTON BEAM POSITION MONITOR CONFIGURATION FOR SMALL-GAP VACUUM CHAMBERS S. H. Kim March 27, 1998 Summary - Induced charges on a four-button beam position monitor (BPM) system attached on a beam chamber of narrow rectangular cross sections are calculated as a 2-D electrostatic problem of image charges. The calculation shows that for a narrow chamber of width/height (2w/2h) >> 1, over 90% of the induced charges are distributed within a distance of 2h from the charged beam position in the direction of the chamber width. Therefore, a four-button system with a button diameter of (2 ~ 2.5)h and no button offset from the beam position is the most efficient configuration. The four-button BPMs used for 8-mm and 5-mm chambers in the APS have relatively low sensitivities because the button locations are outside

375

Development of a low-cost bi-axial intensity-based optical fibre accelerometer for wind turbine blades  

Science Journals Connector (OSTI)

Abstract A bi-axial optical fibre accelerometer was developed for wind turbine monitoring. The sensor was fabricated from intensity-modulated optical fibre, which is low-cost, lightweight and simple in design. The bi-axial acceleration was measured by light intensity coupling between a cantilever fibre and two receiving fibres. Numerical simulation was performed to obtain the light coupling characteristics and the results were used to design the sensor parameters. A prototype was fabricated and the calibration scheme validated experimentally. The performance of the prototype was tested in terms of frequency response and linearity.

Yao Ge; Kevin S. Kuang; Ser Tong Quek

2013-01-01T23:59:59.000Z

376

Shearing and geodesic axially symmetric perfect fluids that do not produce gravitational radiation  

E-Print Network [OSTI]

Using a framework based on the 1+3 formalism we carry out a study on axially and reflection symmetric perfect and geodesic fluids, looking for possible models of sources radiating gravitational waves. Therefore, the fluid should be necessarily shearing, for otherwise the magnetic part of the Weyl tensor vanishes, leading to a vanishing of the super-Poynting vector. However, for the family of perfect, geodesic fluids considered here, it appears that all possible cases reduce to conformally flat, shear--free, vorticity-free, fluids, i.e Friedmann-Roberston-Walker. The super-Poynting vector vanishes and therefore no gravitational radiation is expected to be produced. The physical meaning of the obtained result is discussed.

Herrera, L; Ospino, J; Carot, J

2015-01-01T23:59:59.000Z

377

Axial Ratio of Edge-On Spiral Galaxies as a Test For Extended Bright Radio Halos  

E-Print Network [OSTI]

We use surface brightness contour maps of nearby edge-on spiral galaxies to determine whether extended bright radio halos are common. In particular, we test a recent model of the spatial structure of the diffuse radio continuum by Subrahmanyan and Cowsik which posits that a substantial fraction of the observed high-latitude surface brightness originates from an extended Galactic halo of uniform emissivity. Measurements of the axial ratio of emission contours within a sample of normal spiral galaxies at 1500 MHz and below show no evidence for such a bright, extended radio halo. Either the Galaxy is atypical compared to nearby quiescent spirals or the bulk of the observed high-latitude emission does not originate from this type of extended halo.

Singal, J; Jones, E; Dunlap, H

2015-01-01T23:59:59.000Z

378

Extrusion of Aluminum Tubes with Axially Graded Wall Thickness and Mechanical Characterization  

Science Journals Connector (OSTI)

Abstract In this study the indirect extrusion of seamless aluminum tubes with variable wall thickness was investigated. Therefore, an axially moveable stepped mandrel was applied. Investigations revealed that wall thickness transitions can either be graded over the tube length or very sharp. The microstructures in thin-walled and thick-walled tube sections were investigated. The local variation of the extrusion ratio and with that the tube wall thickness, product velocity and product temperature during the process lead to significantly different local microstructures at TB=400 °C. At TB=500 °C the microstructure was homogeneously recrystallized with similar grain size in all different tube sections. Furthermore, the mechanical tube properties were characterized by three point bending tests.

M. Negendank; S. Müller; W. Reimers

2014-01-01T23:59:59.000Z

379

Axial-scanning low-coherence interferometer method for noncontact thickness measurement of biological samples  

SciTech Connect (OSTI)

We investigated a high-precision optical method for measuring the thickness of biological samples regardless of their transparency. The method is based on the precise measurement of optical path length difference of the end surfaces of objects, using a dual-arm axial-scanning low-coherence interferometer. This removes any consideration of the shape, thickness, or transparency of testing objects when performing the measurement. Scanning the reference simplifies the measurement setup, resulting in unambiguous measurement. Using a 1310 nm wavelength superluminescent diode, with a 65 nm bandwidth, the measurement accuracy was as high as 11.6 {mu}m. We tested the method by measuring the thickness of both transparent samples and nontransparent soft biological tissues.

Kim, Do-Hyun; Song, Chul-Gyu; Ilev, Ilko K.; Kang, Jin U.

2011-02-20T23:59:59.000Z

380

Effect of radial hydrides on the axial and hoop mechanical properties of Zircaloy-4 cladding  

Science Journals Connector (OSTI)

The effect of radial hydrides on the mechanical properties of stress-relief annealed Zircaloy-4 cladding was studied. Specimens were firstly hydrided to different target hydrogen levels between 100 and 600 wt ppm and then thermally cycled in an autoclave under a constant hoop stress to form radial hydrides by a hydride reorientation process. The effect of radial hydrides on the axial properties of the cladding was insignificant. On the other hand, the cladding ductility measurements decreased as its radial hydride content increased when the specimen was tested in plane strain tension. A reference hydrogen concentration for radial hydrides in the cladding was defined for assessing the fuel cladding integrity based on a criterion of the tensile strength 600 MPa. The reference hydrogen concentration increased with the specimen (bulk) hydrogen concentration to a maximum of ?90 wt ppm at the bulk concentration ?300 wt ppm H and then decreased towards higher concentrations.

H.C. Chu; S.K. Wu; K.F. Chien; R.C. Kuo

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "axial magma chamber" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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381

Progress in the Research Programs to Elucidate Axial Cracking Fuel Failure at High Burnup  

SciTech Connect (OSTI)

A fuel failure with an axial crack starting outside the cladding and penetrating inwards was experienced by high burnup BWR fuel rods in power ramp test. On the other hand, no fuel failure caused by power ramp test has been currently reported on PWR fuel rods at burnups higher than 50 GWd/t. Extensive research programs regarding hydrogen behaviors and mechanical performances on irradiated BWR and PWR fuel claddings have been carried out to clarify the mechanism of the axial cracking and to quantify the conditions to cause fuel failure. Hydrogen solid solubility measurement on irradiated Zircaloy-2 materials showed almost comparable results to those on unirradiated ones. Hydride re-distribution and re-orientation behaviors were tested by heating irradiated BWR claddings with Zr-liner under the conditions of applied radial heat flux (temperature gradient) and circumferential stress. Mechanical performances of BWR claddings were evaluated mainly by the internal pressurizing tests. Internal pressurization tests applying various pressurizing sequences, e.g. stepwise increase in pressure with holding intervals, were also conducted to simulate crack propagation behaviors. Some specimens demonstrated characteristic fracture surfaces similar to those observed on the failed fuel rods after the power ramp. Mechanical performances of irradiated PWR claddings were tested at temperatures of 573 to 723 K. Metallographic examination after tensile tests revealed a large number of incipient cracks within the region of cladding outer rim where a concentrated hydride layer (hydride rim) has been formed during irradiation. Crack propagation test using an expanding mandrel device demonstrated the crack propagation at 573 K but no propagation at 658 K. (authors)

Ogata, Keizo; Aomi, Masaki; Baba, Toshikazu; Kamimura, Katsuichiro [Japan Nuclear Energy Safety Organization, 3-17-1 Toranomon, Minato-ku, Tokyo 105-0001 (Japan); Etoh, Yoshinori [Nippon Nuclear Fuel Development Co., Ltd., 2163 Narita-cho, Oarai-machi, Ibaraki 311-1313 (Japan); Ito, Kunio [Grobal Nuclear Fuel - Japan Co., Ltd., 3-1 Uchikawa 2-chone, Yokosuka 239-0836 (Japan); Kido, Toshiya [Nuclear Development Corporation, 622-12 Funaishikawa, Tokai-mura, Ibaraki 319-1111 (Japan); Teshima, Hideyuki [Mitsubishi Heavy Industries, Ltd. 1-1, Wadasaki-cho 1-chome, Hyogo-ku, Kobe 652-8585 (Japan)

2007-07-01T23:59:59.000Z

382

Clean measurements of the nucleon axial-vector and free-neutron magnetic form factors  

Science Journals Connector (OSTI)

We discuss the feasibility of a weak charged current experiment using a low energy electron beam. A first goal is to measure the Q2 dependence of the axial-vector form factor ga (Q 2). It can be measured model-independently and as robustly as for electromagnetic form factors from typical electron scattering experiments in contrast to the methods used so far to measure ga (Q 2). If ga (Q 2) follows a dipole form the axial mass can be extracted with a better accuracy than the world data altogether. The most important detection equipment would be a segmented neutron detector with good momentum and angular resolution that is symmetric about the beam direction and covers a moderate angular range. A high intensity beam (100 uA) is necessary. Beam polarization is highly desirable as it provides a clean measurement of the backgrounds. Beam energies between 70 and 110 MeV are ideal. This range would provide a Q 2 mapping of ga between 0.01 statistical and point to point uncorrelated uncertainties on each point. Such an experiment may also allow to measure the free-neutron magnetic form factor G M n . The experiment employs the usual techniques of electron-nucleon scattering and presents no special difficulty. Higher energy extensions are possible. They could yield measurements of ga (Q 2) up to Q 2=3 GeV2 and the possibility to access other form factors such as the almost unknown pseudoscalar form factor gP . However the experiments become much more challenging as soon as beam energies pass the pion production threshold.

2013-01-01T23:59:59.000Z

383

High-Frequency Effect Due to the Axial Drift Velocity of a Plasma Column  

Science Journals Connector (OSTI)

The scattering of a plane electromagnetic wave with normal incidence (E field perpendicular to the axis) by a plasma column in the presence of a static magnetic induction B0 has been studied earlier. A heretofore unexplained effect, however, is the existence of a scattered axial field EZ even when B0=0. A mechanism responsible for this coupling between the EZ and the transverse E field, in the absence of B0, is investigated here, namely the role of an axial drift velocity vd. The effect observed is a resonance peak of EZ occurring at the same density for which there exists a resonance of the scattered transverse E field which is well explained by a uniform cold-plasma model. The same model is therefore assumed here. In this approximation the plasma can be described by a surface charge density ? due to the HF polarization which gives rise to a surface current density K=?vd. The boundary conditions then lead to the existence of an EZ which, for B0=0, has a sin? dependence when the exciting field has a cos? dependence. When B0?0, a more complicated theoretical spectrum is obtained. Both the position and the angular dependence of the resonances are in very good agreement with experimental data. The effect predicted by this model is, however, more than an order of magnitude below that observed in a mercury plasma column. This phenomenon can be described as the plasma radio-frequency analog of the static field induced by the Roentgen-Eichenwald current.

A. M. Messiaen and P. E. Vandenplas

1966-09-09T23:59:59.000Z

384

Isospin-invariant Skyrme energy-density-functional approach with axial symmetry  

E-Print Network [OSTI]

We develop the isospin-invariant Skyrme-EDF method by considering local densities in all possible isospin channels and proton-neutron (p-n) mixing terms as mandated by the isospin symmetry. The EDF employed has the most general form that depends quadratically on the isoscalar and isovector densities. We test and benchmark the resulting p-n EDF approach, and study the general properties of the new scheme by means of the cranking in the isospin space. We extend the existing axial DFT solver HFBTHO to the case of isospin-invariant EDF approach with all possible p-n mixing terms. Explicit expressions have been derived for all the densities and potentials that appear in the isospin representation. In practical tests, we consider the Skyrme EDF SkM* and, as a first application, concentrate on Hartree-Fock aspects of the problem, i.e., pairing has been disregarded. Calculations have been performed for the (A=78, T~11), (A=40, T~8), and (A=48, T~4) isobaric analog chains. Isospin structure of self-consistent p-n mixed solutions has been investigated with and without the Coulomb interaction, which is the sole source of isospin symmetry breaking in our approach. The extended axial HFBTHO solver has been benchmarked against the symmetry-unrestricted HFODD code for deformed and spherical states. We developed and tested a general isospin-invariant Skyrme-EDF framework. The new approach permits spin-isospin densities that may give rise to, hitherto, unexplored modes in the excitation spectrum. The new formalism has been tested in the Hartree-Fock limit. A systematic comparison between HFODD and HFBTHO results show a maximum deviation of about 10 keV on the total binding energy for deformed nuclei when the Coulomb term is included. Without this term, the results of both solvers agree down to a ~10 eV level.

J. A. Sheikh; N. Hinohara; J. Dobaczewski; T. Nakatsukasa; W. Nazarewicz; K. Sato

2014-05-20T23:59:59.000Z

385

Addendum to the Technical Design Report for the Upgrade of the ALICE Time Projection Chamber  

E-Print Network [OSTI]

This is the addendum to the TDR of the upgrade of the ALICE Time Projection Chamber (CERN-LHCC-2013-020 ; ALICE-TDR-016). The key objective of the upgrade is the replacement of the present MWPC-based readout chambers by detectors that allow continuous operation without active ion gating. In the TDR, we propose a solution that employs stacks of four Gas Electron Multipliers (GEMs) and demonstrate that it fulfills the design specifications, in particular in terms of intrinsic position resolution, energy resolution, and ion backflow. In this document we demonstrate with additional results from both detector R&D and simulations that the technological solution chosen in the TDR has sufficient safety margin for a successful campaign with the upgraded detector in RUN 3 and beyond.

The ALICE Collaboration

2015-01-01T23:59:59.000Z

386

Portable chamber for the study of UHV prepared electrochemical interfaces by hard x-ray diffraction  

SciTech Connect (OSTI)

We report on a new electrochemical cell setup, combined with a portable UHV chamber, for in situ x-ray diffraction using synchrotron radiation. In contrast to more traditional electrochemical sample preparation schemes, atomically clean and well-ordered surfaces are routinely prepared by UHV methods, even in the case of reactive elements or alloys. Samples can be transferred from larger UHV systems into the portable chamber without exposure to ambient air. They can then be studied successively in UHV, in controlled gas atmospheres, and in contact with electrolyte solutions under applied electrochemical potential. The electrochemical setup employs a droplet geometry, which guarantees good electrochemical conditions during in situ x-ray measurements combined with voltammetry. We present first experimental results of Cu deposition on GaAs(001) and on freshly produced nanometric Pd(001) islands on Cu{sub 0.83}Pd{sub 0.17}(001), respectively.

Renner, Frank Uwe; Gruender, Yvonne; Zegenhagen, Joerg [European Synchrotron Radiation Facility, BP 220, 38043 Grenoble (France)

2007-03-15T23:59:59.000Z

387

Acoustic studies for alpha background rejection in dark matter bubble chamber detectors  

SciTech Connect (OSTI)

COUPP (Chicagoland Observatory for Underground Particle Physics) is an experiment with bubble chambers able to detect dark matter directly either with Spin-Dependent or with Spin-Independent interactions. The target material is a superheated liquid (usually CF3I) that can be bubble nucleated due to nuclear recoils produced by elastic collisions of dark matter particles. The bubble growth inside the chamber is accompanied with an acoustic signature. The acoustic technique has been successfully used to have a good alpha discrimination (about 99%). In this paper, we present different studies and results related with the characterization of the acoustic properties of the detector and the different phenomena involved in the acoustic measurements of the bubble growth, such as sound generation, sound transmission and optimization of piezoelectric transducers.

Bou-Cabo, M.; Felis, I.; Ardid, M.; Collaboration: COUPP Collaboration

2013-08-08T23:59:59.000Z

388

Single-scattering properties of tri-axial ellipsoidal mineral dust aerosols: A database for application to radiative transfer calculations  

E-Print Network [OSTI]

Single-scattering properties of tri-axial ellipsoidal mineral dust aerosols: A database Applications and Research, Camp Spring, MD 20746, USA a r t i c l e i n f o Article history: Received 14 Optical properties Database a b s t r a c t This paper presents a user-friendly database software package

Liou, K. N.

389

Department of Mechanical and Nuclear Engineering Fall 2011 Torque and Axial Measurement Device for Soil Abrasion Testing  

E-Print Network [OSTI]

PENNSTATE Department of Mechanical and Nuclear Engineering Fall 2011 Torque and Axial Measurement Device for Soil Abrasion Testing Overview The Penn State Department of Energy and Mineral Engineering to completely re-design with five weeks left. This left minimal time for machining, assembly, testing

Demirel, Melik C.

390

Coaching the Brass Quintet: Developing Better Student Musicians Through Chamber Music  

E-Print Network [OSTI]

students match articulation in order to facilitate ease and clarity in making music. If the students are able to listen and match appropriately, then the amount of time spent making music can be increased. Articulation is a musical device, and can be used... technical, musical, and most importantly extra-musical abilities from a 2 young age. These essential extra-musical skills such as critical self-reflection, pro-active listening, and leadership, are a chamber coach’s primary responsibility...

Miller, Albert Edward

2014-05-31T23:59:59.000Z

391

Dissolved inorganic carbon isotopic composition of low-temperature axial and ridge-flank hydrothermal fluids of the Juan de Fuca Ridge  

E-Print Network [OSTI]

carbon isotopic composition of low-temperature axial and ridge-flank hydrothermal fluids of the Juan deDissolved inorganic carbon isotopic composition of low-temperature axial and ridge-flank hydrothermal fluids of the Juan de Fuca Ridge Brett D. Walker a,, Matthew D. McCarthy a , Andrew T. Fisher b

Fisher, Andrew

392

Fail-safe ion chamber errant beam detector tailored for personnel protection  

SciTech Connect (OSTI)

This fail-safe ion chamber system is designed to be part of the personnel safety system (PSS) for the Los Alamos Neutron Scattering Center (LANSCE) at the Los Alamos National Laboratory. Its job is to protect the occupants of the experimental areas from large radiation doses caused by errant beam conditions during beam transport from the Proton Storage Ring (PSR) to the LANSCE neutron spallation target. The worst case beam spill scenario is calculated to result in a personnel exposure of about 0.01 Gys/s (1 rad/s). Although the preferred solution is to increase the bulk shielding between the beam line and the experimental area, the physical dimensions of the site do not permit an adequate amount of shielding to be added. The solution adopted is a layered system of three types of highly reliable detector systems: a current limiter system located in the beam line, a neutron detector system located in the experimental areas, and an ion chamber system located on the walls of the beam line tunnels. The ion chamber system is capable of shutting off the beam in less than 0.5 s, resulting in a worst case personnel exposure of 0.005 Gys (0.5 rad). 4 figs.

Plum, M.A.; Browman, A.A.; Brown, D.; Lee, D.M.; McCabe, C.W.

1989-01-01T23:59:59.000Z

393

Numerical simulations of industrial-scale combustion chamber - LES versus RANS  

Science Journals Connector (OSTI)

In this work we focus on the simulation of the process of biomass syngas combustion in the industrial combustion chamber directly linked with gasification chamber, where this gas is continuously producing from the biomass. Conflicting demands from the engineers to have rapid results and hints how to ensure the best conditions for combustion of this particular fuel and to lower the emission of pollutants, with simultaneously deep view inside the process and its stability motivates us to use both the RANS and LES techniques of turbulence modelling, compare it and take their advantages. We designed and performed series of 3D numerical simulations of both cold flow and combustion in complex geometry of industrial burner. It seems to us that the proper approach for modelling of biomass syngas combustion is steady flamelets model. Simulations performed with RANS closure are used as the initialisation of LES models, but their main goal is to predict the long-time oscillation of pressure and temperature observed in the working combustion chamber. On the other hand the main goal of the simulations with LES closure is to predict the proper level of short-time behaviour of the flame and local phenomena.

Kamil Kwiatkowski; Daniel Jasi?ski; Konrad Bajer

2011-01-01T23:59:59.000Z

394

Tribological study on hydrostatic slipper bearing with annular orifice damper for water hydraulic axial piston motor  

Science Journals Connector (OSTI)

Hydrostatic slipper bearing is an effective way to maintain a fluid film between slipper pad and swash plate that slide against each other, and thereby mitigate direct surface-to-surface contact in water hydraulic axial piston motor (WHAPM). The hydrostatic slipper bearing with an annular orifice damper is proposed, and the reaction force of the bearing in WHAPM is investigated. The effects from the friction within the cylinder bore, the dynamics of the piston, and the centrifugal force of the piston–slipper assembly are examined. The characteristic equation of the hydrostatic slipper bearing with an annular orifice damper is formulated, where the effects of various geometric parameters (e.g. damping length, supporting length, and clearance between the piston and the cylinder bore) are reflected. The relevant criterion for designing the hydrostatic slipper bearing can then be established. Results of the theoretical analyses indicate that (a) the friction coefficient, the swash plate angle, and the inertia and centrifugal loads (generated under a high motor rotating speed) would have significant influences on the reaction force; (b) an appropriate swash plate angle can help eliminate the fluctuation of the reaction force; (c) the load-carrying capacity of the hydrostatic slipper bearing is more sensitive to the damping length than to the supporting length of the piston; (d) a short damping length can help enhance the load-carrying capacity; (e) a small clearance between the piston and the cylinder bore would help improve the adaptive ability to the varying load for the hydrostatic slipper bearing, when clearance between the slipper pad and the swash plate ranges from 5 to 20 ?m. Experimental studies of the slipper pads sliding against the swash plates are conducted at a custom-manufactured test apparatus, given different material combinations and design methods. The experimental results indicate that the hydrostatic slipper bearing with an annular orifice damper would decrease the possibility of the severe wear between the slipper pad and the swash plate in comparison with the hydrostatic clamping ratio bearing in the WHAPM, and the CRA laser cladding (compared to the ZrO2·MgO-plasma-sprayed coating and the stainless steel 2Cr13) is a promising candidate as the tribo-material when sliding against composite materials in water lubrication system. The hydrostatic slipper bearing with an annular orifice damper has been successfully applied to a WHAPM developed at the Huazhong University Science and Technology. The result demonstrates that the developed bearing has a satisfactory tribolgical performance, and can be extended to the manufacture of water hydraulic axial piston pumps.

S.L. Nie; G.H. Huang; Y.P. Li

2006-01-01T23:59:59.000Z

395

Performance of a Single-Chamber Microbial Fuel Cell Degrading Phenol: Effect of Phenol Concentration and External Resistance  

Science Journals Connector (OSTI)

The performance of a single-chamber microbial fuel cell (MFC) using wastewater containing phenol as the anodic fuel was evaluated. The evaluation was performed considering ... presence of different phenol concent...

Germán Buitrón; Iván Moreno-Andrade

2014-09-01T23:59:59.000Z

396

Multi-stage axial-flux PM machine for wheel direct drive  

SciTech Connect (OSTI)

The design of direct-driven wheel motors must comply with diameter restriction due to housing the motor in a wheel rim and allow the achievement of very high torque density and overload capability. Slotless axial-flux permanent magnet machines (AFPMs) prove to be one best candidate for application in electric vehicles as direct-drive wheel motors, as in comparison with conventional machines they allow designs with higher compactness, lightness and efficiency. The paper presents a newly-conceived AFPM which has multi-stage structure and water-cooled ironless stator. In the proposed new topology of the machine the space formerly occupied by the toroidal core becomes a water duct, which removes heat directly from the interior surface of the stator winding. The high efficiency of the machine cooling arrangement allows long-term 100% overload operation and great reduction of the machine weight. The multistage structure of the machine is suited to overcome the restriction on the machine diameter and meet the torque required at the wheel shaft. The paper gives guidelines for the design of a multi-stage AFPM with water-cooled ironless stator, and describes characteristics of a two-stage prototype machine rated 220 Nm, 1,100 rpm.

Caricchi, F.; Crescimbini, F.; Mezzetti, F.; Santini, E. [Univ. of Rome La Sapienza (Italy). Dept. of Electrical Engineering

1995-12-31T23:59:59.000Z

397

Design of a high power density, permanent magnet, axial gap dc motor  

SciTech Connect (OSTI)

In the design of drive motors for undersea vehicles, the premium placed on noise suppression suggests the use of a brush-commutated dc motor. The additional constraints of weight and volume, as well as unusual configuration, presents the axial air-gap configuration, with a permanent magnet field, as a viable candidate. In such a configuration the design of the brushes and commutator and the resulting structure becomes critical. The report describes a novel solution to this problem. The basic motor consists of two discs containing permanent magnets on either side of a magnetic structure containing the copper windings. An advantage of this motor concept is that copper cooling may easily be accomplished through the use of liquid circulating through the stator windings. The role of field and armature in a conventional disc motor configuration are reversed. The two discs containing the permanent magnets are rotating. The brushes are on the discs. The magnetic structure with the coils is stationary. The commutator bars are imbedded in the stationary member. Input power is supplied to the brushes through a brush-and-slip ring assembly. An electromagnetic design analysis for a 92 ft-lb, 700 rpm motor was performed. A finite element analysis has been conducted and the results show that magnetic saturation is not a limiting factor in this design. The motor torque is achievable within weight and volume constraints. 9 figs., 1 tab.

Hawsey, R.A.; Daniel, D.S.; Thomas, R.J. (Oak Ridge National Lab., TN (USA)); Bailey, J.M. (Tennessee Univ., Knoxville, TN (USA))

1990-01-01T23:59:59.000Z

398

Axial gap permanent-magnet machine with reluctance poles and PM element covers  

SciTech Connect (OSTI)

An electric machine (10) has a disk-shaped rotor (24) disposed in an operating space between two opposing stator assemblies (11, 12) to provide two axial air gaps (15, 16). The rotor (24) has a hub (28) and an outer ring (26) of non-magnetic material and is further provided with a plurality of permanent magnetic elements (25) for coupling flux that is induced by the magnetic field of the stator assemblies (11, 12). The permanent magnetic elements (25) are spaced apart and reluctance poles (27) are positioned in spaces between the magnetic elements (25) to couple additional flux induced by the magnetic field of the stator assemblies (11, 12). Various constructions and shapes (40-45) for the PM magnetic elements (25) are disclosed, and including PM covers (60) of ferromagnetic material for enhancing q-axis flux in the air gaps (15, 16) and for reducing harmonics where toothed stators are used. Methods of providing increased torque using the the various rotor constructions are also disclosed.

Hsu, John S [Oak Ridge, TN; McKeever, John W [Oak Ridge, TN

2009-04-07T23:59:59.000Z

399

The twofold emergence of the $a_1$ axial vector meson in high energy hadronic production  

E-Print Network [OSTI]

The high statistics COMPASS results on diffractive dissociation $\\pi N \\rightarrow \\pi \\pi \\pi N$ suggest that the isospin $I=1$ spin-parity $J^{PC}= 1^{++}$ $a_1(1260)$ resonance could be split into two states: $a_1(1260)$ decaying into an S-wave $\\rho\\pi$ system, and $a_1^\\prime(1420)$ decaying into a P-wave $f_0(980)\\pi$ system. We analyse the reaction by incorporating our previous treatment of resonant re-scattering corrections in the Drell-Deck forward production process. Our results show that the COMPASS results are fully consistent with the existence of a single axial-vector $a_1$ resonance. The characteristic structure of the production process, which differs in the two orbital angular momentum states, plays a crucial role in this determination. Provided the theoretical analysis of the reaction is done in a consistent manner, this single resonance produces two peaks at different locations in the two channels, with a rapid increase of the phase difference between their amplitudes arising mainly from th...

Basdevant, Jean-Louis

2015-01-01T23:59:59.000Z

400

Creep Testing Plastic-Bonded Explosives in Uni-axial Compression  

SciTech Connect (OSTI)

High fidelity measurements of time-dependent strain in the plastic-bonded explosives LX-17-1 and PBX 9502 have been performed under constant, uni-axial, compressive load using a custom designed apparatus. The apparatus uses a combination of extensometers and linear variable differential transformers coupled with a data acquisition system, thermal controls, and gravitational loading. The materials being tested consist of a crystalline explosive material mixed with a polymeric binder. The behavior of each material is related to the type of explosive and to the percentage and type of binder. For any given plastic-bonded explosive, the creep behavior is also dependent on the stress level and test temperature. Experiments were conducted using a 3 x 3 stress-temperature matrix with a temperature range of 24 C to 70 C and with stresses ranging from 250-psi to 780-psi. Analysis of the data has shown that logarithmic curve fits provide an accurate means of quantification and facilitate a long-term predictive capability. This paper will discuss the design of the apparatus, experimental results, and analyses.

Gagliardi, F J; Cunningham, B J

2008-03-13T23:59:59.000Z

Note: This page contains sample records for the topic "axial magma chamber" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Control rod worth and related nuclear characteristics of an axially heterogeneous liquidmetal fast breeder reactor core  

SciTech Connect (OSTI)

An axially heterogeneous core (AHC) concept is applied to a 1000-MW(electric)-class tank-type liquidmetal fast breeder reactor (LMFBR). This AHC is characterized by a disk-shaped internal blanket with a radial thickness adjustment at the core midplane. The nuclear characteristics connected with control rod worth of the AHC are analyzed and compared with those of a homogeneous core (HOC) of the same power rating. The neutronics analysis shows that the reactivity insertion due to the vertical displacement of control rods relative to the core, which is an important safety characteristic of a tank-type LMFBR core, is significantly decreased in the AHC because of the reduced control worth requirement and smaller peakto-average differential worth in the primary control system. This allows the AHC to have a vertical displacement 50% greater than that of the HOC and may offer less rigid design conditions for roof slab stiffness and core support systems in a tank-type LMFBR. A reduction in the number of primary control rods is also possible because of a smaller control worth requirement and a better power peaking factor. The work was sponsored by a federation of Japanese electric power companies and performed under the guidance of the fast breeder reactor project office.

Kawashima, K.; Inayaki, T.; Inoue, K.; Kaneto, K.

1985-08-01T23:59:59.000Z

402

Axial effects of xenon-samarium poisoning in the advanced test reactor  

SciTech Connect (OSTI)

The paper details an analytical study of the time-dependent behavior in the spatial distributions of xenon and samarium fission product poisons in the Advanced Test Reactor (ATR) during operation and after shutdown. The results of this study provide insight into the behavior and significance of the changing spatial distributions of fission product poisons with respect to the prediction of shim positions at critical for reactor restart after a xenon shutdown. The study was performed with the PDQ neutron diffusion theory code and ENDF/B-V cross sections using a one-dimensional radial model of an ATR lobe and a two-dimensional radial-axial (RZ) model of an ATR lobe. The PDQ results were supported by a review of the basic differential equations, which describe the buildup and decay of the xenon and samarium fission product poisons and precursors. The ATR is a 250-MW, uranium-aluminum-fueled reactor used to study the effects of irradiation on reactor materials. Forty highly enriched uranium fuel elements are arranged in a serpentine configuration within the compact core resulting in a very high power density of (1.0 MW/[ell] of core).

Auslander, D.J.; Smith, A.C.; McCracken, R.T. (Idaho National Engineering Lab., Idaho Falls (United States))

1990-01-01T23:59:59.000Z

403

Axisymmetry vs. nonaxisymmetry of hydromagnetic Taylor-Couette flows with axial electric currents  

E-Print Network [OSTI]

The stability of a Taylor-Couette flow with resting outer cylinder under the influence of a homogeneous axial electric current is investigated. In the linear theory the critical Reynolds number for axisymmetric perturbations Re=68 is not influenced by the current-induced magnetic field but all the axisymmetric magnetic perturbations decay. The nonaxisymmetric perturbations with |m|=1 are excited even without rotation for large enough Hartmann numbers ('Tayler Instability') but the growth rate increases with Reynolds number. In the nonlinear regime shear energy is pumped into the neighboring modes m=0 and |m|=2. The ratio q of the energy of the magnetic |m|=1 modes and the toroidal background field is very small for the pure (non-rotating) Tayler instability and grows strongly if differential rotation is present. For super-Alfv\\'enic rotation the energy in the |m|=1 modes of flow and field are in equipartition, with about 1% of the centrifugal energy of the inner cylinder. If the electric current is strong eno...

Gellert, M; Rüdiger, G

2013-01-01T23:59:59.000Z

404

Numerical simulation of supercritical heat transfer under severe axial density gradient in a narrow vertical tube  

SciTech Connect (OSTI)

A number of computational works have been performed so far for the simulation of heat transfer in a supercritical fluid. The simulations, however, faced a lot of difficulties when heat transfer deteriorates due either to buoyancy or by acceleration. When the bulk temperature approaches the pseudo-critical temperature the fluid experiences a severe axial density gradient on top of a severe radial one. Earlier numerical calculations showed, without exception, unrealistic over-predictions, as soon as the bulk temperature exceeded the pseudo-critical temperature. The over-predictions might have been resulted from an inapplicability of widely-used turbulence models. One of the major causes for the difficulties may probably be an assumption of a constant turbulent Prandtl number. Recent research, both numerical and experimental, indicates that the turbulent Prandtl number is never a constant when the gradient of physical properties is significant. This paper describes the applicability of a variable turbulent Prandtl number to the numerical simulation of heat transfer in supercritical fluids flowing in narrow vertical tubes. (authors)

Bae, Y. Y.; Hong, S. D.; Kim, Y. W. [Korea Atomic Energy Research Inst., 1045 Daedeokdaero, Daejeon (Korea, Republic of)

2012-07-01T23:59:59.000Z

405

Algebraic stress model for axial flow in a bare rod-bundle  

SciTech Connect (OSTI)

The problem of predicting transport properties for momentum and heat across the boundaries of interconnected channels has been the subject of many investigations. In the particular case of axial flow through rod-bundles, transport coefficients for channel faces aligned with rod centers are known to be considerably higher than those calculated by simple isotropic theories. And yet, it was been found that secondary flows play only a minor role in this overall transport, being turbulence highly enhanced across that hypothetical surface. In order to numerically predict the correct amount of the quantity being transported, the approach taken by many investigators was then to artificially increase the diffusion coefficient obtained via a simple isopropic theory (usually the standard k-epsilon model) and numerically match the correct experimentally observed mixing rates. The present paper reports an attempt to describe the turbulent stresses by means of an Algebraic Stress Model for turbulence. Relative turbulent kinetic energy distribution in all three directions are presented and compared with experiments in a square lattice. The strong directional dependence of transport terms are then obtained via a model for the Reynolds stresses. The results identify a need for a better representation of the mean-flow field part of the pressure-strain correlation term.

de Lemos, M.J.S.

1987-01-01T23:59:59.000Z

406

New efficiency charts for the optimum design of axial flow turbines for organic Rankine cycles  

Science Journals Connector (OSTI)

Abstract Turbine efficiency plays a key role in the design optimization of \\{ORCs\\} (organic Rankine cycles) and should be properly evaluated for an accurate estimate of the real power production. Its value is in general assumed as given in the design optimization procedure, without a check that it can be really achieved in the resulting working conditions. The peculiar properties of high molecular weight fluids markedly influence turbine design and ask for turbine design criteria specifically tailored to ORCs. In this work a meanline design procedure for single stage axial flow turbines is developed to find optimum turbine geometry and efficiency in a wide range of operating conditions. Unlike previous literature, real fluid properties and very recent loss models are implemented. The variation of the predicted turbine efficiency with loading coefficient, flow coefficient, specific speed and specific diameter is shown through new general maps that explicitly take into account the strong influence of compressibility and turbine size through the volumetric expansion ratio and size parameter, respectively. All these maps can be included in a general design optimization procedure of the ORC system to help select the optimum design point, overcoming any arbitrary assumptions on turbine efficiency.

Luca Da Lio; Giovanni Manente; Andrea Lazzaretto

2014-01-01T23:59:59.000Z

407

Critical Power Correlation for Axially Uniformly Heated Tight-Lattice Bundles  

SciTech Connect (OSTI)

Critical power experiments were carried out, and the critical power correlation for axially uniformly heated tight bundles has been derived based on the present experimental data and data sets measured by the Bettis Atomic Power Laboratory. The shape of the test section simulates the fuel assembly of the reduced-moderation water reactor (RMWR), which is a water-cooled breeder reactor with a core of the tight triangular fuel rod arrangement. The obtained correlation covers the following conditions: channel geometry (triangular arrangement bundle of 7 to 20 rods, 6.6 to 12.3 mm in rod diameter, 1.0- to 2.3-mm gap between rods, 1.37 to 1.8 m in heated length), mass velocity of 100 to 2500 kg/(m{sup 2}s), inlet quality of -0.2 to 0, pressure of 2 to 8.5 MPa, and radial peaking factor of 0.98 to 1.5, which include uniform, center-peak, and liner transverse heat flux distribution data. An excellent agreement was obtained between the developed correlation and data (371 points) within an error of {+-}4.6%.

Kureta, Masatoshi; Akimoto, Hajime [Japan Atomic Energy Research Institute (Japan)

2003-07-15T23:59:59.000Z

408

Effect of fuel injection velocity on MILD combustion of syngas in axially-staged combustor  

Science Journals Connector (OSTI)

Abstract The role of fuel injection velocity on MILD (Moderate or Intense Low-oxygen Dilution) combustion of coal-derived syngas was examined in an axially staged combustor, where the secondary air was mixed with the flue gases from the gas generation zone to produce hot and diluted oxidant prior to its mixing with the secondary fuel. The global flame signatures, OH? radicals distribution, and exhaust emissions were obtained through experimental measurements, while the mixing behavior between the secondary fuel and oxidant was numerically studied. Higher secondary fuel injection velocity within 199–299 m/s facilitated the earlier entrainment of oxidizer into the secondary fuel and increased the flame lift-off height, resulting in a lower flame temperature, a more distributed reaction zone and reduced \\{NOx\\} emissions, but higher pressure loss and CO formation. The MILD regime yields lower \\{NOx\\} emissions compared to the traditional diffusion combustion mode, and the N2O-intermediate mechanism dominates the NO production in the syngas MILD flame with adiabatic flame temperature lower than 1565 K according to the prediction of the chemical reactor network model.

Ming-ming Huang; Wei-wei Shao; Yan Xiong; Yan Liu; Zhe-dian Zhang; Fu-lin Lei; Yun-han Xiao

2014-01-01T23:59:59.000Z

409

Flame kernel characterization of laser ignition of natural gas–air mixture in a constant volume combustion chamber  

Science Journals Connector (OSTI)

In this paper, laser-induced ignition was investigated for compressed natural gas–air mixtures. Experiments were performed in a constant volume combustion chamber, which simulate end of the compression stroke conditions of a SI engine. This chamber simulates the engine combustion chamber conditions except turbulence of air–fuel mixture. It has four optical windows at diametrically opposite locations, which are used for laser ignition and optical diagnostics simultaneously. All experiments were conducted at 10 bar chamber pressure and 373 K chamber temperature. Initial stage of combustion phenomena was visualized by employing Shadowgraphy technique using a high speed CMOS camera. Flame kernel development of the combustible fuel–air mixture was investigated under different relative air–fuel ratios (?=1.2?1.7) and the images were interrogated for temporal propagation of flame front. Pressure-time history inside the combustion chamber was recorded and analyzed. This data is useful in characterizing the laser ignition of natural gas–air mixture and can be used in developing an appropriate laser ignition system for commercial use in SI engines.

Dhananjay Kumar Srivastava; Kewal Dharamshi; Avinash Kumar Agarwal

2011-01-01T23:59:59.000Z

410

Verifying Sensor Response to Difficult Chemicals with a New Test Chamber Concept  

SciTech Connect (OSTI)

In this article we discuss the application of technology innovations to optimize detection of hard-to-measure (less- or semi-volatile) compounds. These chemicals are found all around us: in pesticides and herbicides, the higher boiling polyaromatic hydrocarbons in diesel exhaust, and linked polyurethane foams in products ranging from hiking boots to acoustic ceilings. They appear in low concentrations and evaporate very slowly. These heavier chemicals are rarely measured accurately because they stick to surfaces and sampling equipment and, consequently, are not reliably sampled or delivered to analytical detectors. It’s like trying to identify cold, sticky honey by getting it to flow in through a sampling tube to a detector –it will hardly move. Honey generally coats out on surfaces and sample lines to the extent that even if it is detected, the amount present is vastly underestimated. Researchers at Pacific Northwest National Laboratory (PNNL) addressed the problem by developing a chamber facility with instrumentation that can overcome the under-reporting of these ubiquitous chemical compounds. The atmospheric chemistry chamber provides a controlled environment in which to certify the accuracy of and conditions under which sensors can best respond to volatile and semi-volatile chemicals. The facility is designed to handle and measure chemicals at the levels at which they are found in nature. Test environments can be created in which atmospheric concentrations are at low part-per-trillion concentrations. These concentrations are equivalent to an herbicide off-gassing from a commercially grown apple. The chamber can be set up to simulate releases ranging from industrial vents with high concentrations to releases from surfaces, soils, and/or vegetation where the concentrations are low.

Maughan, A. D.; Birnbaum, Jerome C.; Probasco, Kathleen M.

2004-06-01T23:59:59.000Z

411

Streamer chamber study of intermediate-energy nuclear collisions with CCD cameras  

SciTech Connect (OSTI)

A system of three charge-coupled device (CCD) cameras has been designed and built to record nuclear collisions in a streamer chamber. This technical development significantly enhances the usefulness of streamer chambers as large solid angle ({approx}4{pi} sr) detectors for exclusive measurements in nuclear physics. The system has been used in an experiment designed to study nearly-central collisions of Nb + Nb at 100 and 180 MeV/nucleon. Computer codes have been developed that significantly reduce the amount of operator intervention in the data analysis. One of the most interesting predictions of fluid-dynamical models and VUU calculations for heavy-ion collisions is the sideward emission of nuclear matter, due to the high compression crated during the collision (Stoe 80, Mol 85). The transverse-momentum flow analysis introduced by Danielewicz and Odyniec (Dan 85) allows to calculate the amount of sideward momentum carried by the emitted fragments, while minimizing the distortions caused by finite-multiplicity effects. This momentum flow analysis has been performed on our 180 MeV/nucleon data. The slope of the mean transverse momentum per nucleon vs. rapidity curve at mid-rapidity, or flow, was found to be 47.0 {plus minus} 11.3 MeV/c/nucleon. In order to compare our results to those obtained from other experiments, scale-invariant transverse momentum, p{sup x}, and rapidity, y, have been introduced (Bal 84). The p{sup x} vs. y curve extracted from our data has been compared with the curves obtained for various systems in streamer chamber plus photographic film (Dan 85, Ren 84) and plastic ball experiments (Dos 85), and the shapes have been found to be very similar. The scale-invariant flow, F, for 180 MeV/nucleon Nb + Nb is 0.16 {plus minus} 0.04.

Angius, S.P.

1987-01-01T23:59:59.000Z

412

HEBT MOMENTUM SCRAPER, H+ RAY TRACE SIMULATION AND VACUUM CHAMBER DESIGN.  

SciTech Connect (OSTI)

In the 1MW Spallation Neutron Source (SNS), the High-Energy Beam Transfer line (HEBT) connects the LINAC to the accumulator ring. A major requirement of the SNS complex is to have low uncontrolled beam loss (lnA/m), to allow hands on maintenance. The vacuum requirement for the HEBT is 5x10{sup {minus}8} Torr. Excessive H{sup {minus}} stripping will occur above this pressure and increase losses in the machine. The HEBT is also equipped with three sets of beam halo scrapers, one for momentum and two for transverse collimation. The momentum scraper is located at a maximum dispersion point, between the 3rd dipole magnet (DD3) of HEBT and the 14th quadrupole (Q14) of the HEBT line. The momentum scraper uses movable foils that strip the H{sup {minus}} beam that has momentum spread (0.2%<{delta}p/p<0.6%) into H{sup +}, and the H{sup +} ions are then directed out of the HEBT beam line to a beam dump by the next bending magnet DD4 (4th dipole of HEBT). In order to ensure that the extracted H{sup +} beam travels inside the extraction chamber to minimize the radiation in the beam dump station region, we performed H{sup +} particle tracking to determine the outer boundaries and the angle of the Y-type vacuum chamber that will contain the H{sup +} beam. The development and design of the special HEBT momentum scraper extraction and exit chamber, and the relevant H{sup +} trajectories are presented in this paper.

HE,P.; HSEUH,H.C.; RAPARIA,D.; TSOUPAS,N.; WEISS,D.

2001-06-18T23:59:59.000Z

413

Analysis of cladding deformation over plenum axial gaps in Zircaloy-clad fuel rods. LWBR Development Program  

SciTech Connect (OSTI)

An analytical model has been developed to predict deformation of unirradiated Zircaloy cladding over axial gaps in plenum regions of fuel rods. This model uses the ACCEPT finite element computer program to calculate the elastic-plastic deformation of cladding due to net external pressure. Progressive increase in gap length (from elongation of cladding below the gap due to Zircaloy growth and pellet-cladding interaction induced creep and from fuel stack shrinkage due to densification of fuel pellets) and deformations of fuel pellets and support sleeve which bound the axial gap in LWBR type blanket fuel rods are included in the model. The thermal creep representation used is based on data from uniaxial creep testing of fuel rod tubing.

Gorscak, D.A.; Pfennigwerth, P.L.

1982-12-01T23:59:59.000Z

414

Management of unconverted light for the National Ignition Facility target chamber  

SciTech Connect (OSTI)

The NIF target chamber beam dumps must survive high x-ray, laser, ion, and shrapnel exposures without excessive generation of vapors or particulate that will contaminate the final optics debris shields, thereby making the debris shields susceptible to subsequent laser damage. The beam dumps also must be compatible with attaining and maintaining the required target chamber vacuum and must not activate significantly under high neutron fluxes. Finally, they must be developed, fabricated, and maintained for a reasonable cost. The primary challenge for the beam dump is to survive up to 20 J/cm{sup 2} of lpm light and 1 - 2 J/cm{sup 2} of nominally 200 - 350 eV blackbody temperature x rays. Additional threats include target shrapnel, and other contamination issues. Designs which have been evaluated include louvered hot-pressed boron carbide (B{sub 4}C) or stainless steel (SS) panels, in some cases covered with transparent Teflon film, and various combinations of inexpensive low thermal expansion glasses backed by inexpensive absorbing glass. Louvered designs can recondense a significant amount of ablated material that would otherwise escape into the target chamber. Transparent Teflon was evaluated as an alternative way to capture ablated material. The thin Teflon sheet would need to be replaced after each shot since it exhibits both laser damage and considerable x- ray ablation with each shot. Uncontaminated B{sub 4}C, SS, and low thermal expansion glasses have reasonably small x-ray and laser ablation rates, although the glasses begin to fail catastrophically after 100 high fluence shots. Commercially available absorbing glasses require a pre-shield of either Teflon or low thermal expansion glass to prevent serious degradation by the x-ray fluence. Advantages of the hot-pressed B{sub 4}C and SS over glass are their performance against microshrapnel, their relative indifference to contamination, and their ability to be refurbished by aggressive cleaning using CO{sub 2} pellets, glass beads, high pressure water or ultrasonic tanks. In addition the expected replacement rate to avoid catastrophic failure makes the glass option more costly. SS is less expensive, more easily formed into a louver design with high capture efficiency, and otherwise equivalent to B{sub 4}C. Hence, it would be preferred as long as debris shield damage is not substantially greater for SS as compared to damage from an equivalent mass of contamination of B{sub 4}C. If debris shield damage is problematic, the escape of SS could be mitigated by use of a transparent Teflon film. The Teflon film would require increased target chamber pumping and cleaning capability to accommodate the x-ray decomposition products.

Anderson, A. T.; Bletzer, K.; Burnham, A. K.; Dixit, S; Genin, F. Y.; Hibbard, W.; Norton, J.; Scott, J. M.; Whitman, P. K.

1998-07-08T23:59:59.000Z

415

Blood meal host preferences of Culex salinarius Coquillett (Diptera : culicidae) in Chambers County, Texas  

E-Print Network [OSTI]

: Culicidae) in Chambers County, Texas. (December 1994) John Paul Grieco, B. S. , University of Notre Dame Chair of Advisory Committee: Dr. Jimmy K. Olson Bloodmeal host preferences were assessed for ~ sQiDgi~ populations occurring along the upper Gulf...)(Seeley and Bickley 1974) and St. Louis encephalitis (Nayar et al. 1986) . Also, ~x. B~l' -a~i populations are often found in areas that are associated with large numbers of avian hosts which serve as possible reservoirs for eastern equine encephalitis (EEE...

Grieco, John Paul

2012-06-07T23:59:59.000Z

416

Conceptual design for a fast neutron ionization chamber for fusion reactor plasma diagnostics  

SciTech Connect (OSTI)

A conceptual design for a radiation-hard ``pointing`` fast neutron ionization chamber that is capable of delivering a 1 MHz countrate of T(D,n) events at ITER is given. The detector will use a {approximately}1 cm{sup 3} volume of CO{sub 2} fill gas at 0.1 bar pressure in a 500 V/cm electric field. The pulse widths will be {approximately}10 ns, enabling it to operate in a flux of {approximately} 6 {times} 10{sup 13} DT n/cm{sup 2}/sec. A special collimator design is used, giving an estimated angular resolution of 4.5 degrees HWHM.

Sailor, W.C.; Barnes, C.W.

1994-06-01T23:59:59.000Z

417

Study of the calibration of X-T relation for the BESIII drift chamber  

E-Print Network [OSTI]

This paper introduces the calibration of the time-to-distance relation for the BESIII drift chamber. The parameterization of the time-to-distance relation is presented. The studies of left-right asymmetry and the variation with the entrance angle are performed. The impact of dead channels on the time-to-distance relation is given special attention in order to reduce the shifts of the measured momenta for the tracks passing near dead cells. Finally we present the spatial resolution (123 {\\mu}m) for barrel Bhabha events (|cos{\\theta}|data taken in 2012.

Xiao-Lin Kang; Ling-Hui Wu; Zhi Wu; Tao Luo; Chen Hu; Hai-Xai Wang; Shuang-Shi Fang; Kang-Lin He; Wei-Dong Li; Wei-Guo Li; Ze-Pu Mao; Liang-Liang Wang; Ye Yuan; Yao Zhang

2014-05-14T23:59:59.000Z

418

MicroBooNE: A New Liquid Argon Time Projection Chamber Experiment  

SciTech Connect (OSTI)

Liquid Argon Time Projection Chamber detectors are well suited to study neutrino interactions, and are an intriguing option for future massive detectors capable of measuring the parameters that characterize neutrino oscillations. These detectors combine fine-grained tracking with calorimetry, allowing for excellent imaging and particle identification ability. In this talk the details of the MicroBooNE experiment, a 175 ton LArTPC which will be exposed to Fermilab's Booster Neutrino Beamline starting in 2011, will be presented. The ability of MicroBooNE to differentiate electrons from photons gives the experiment unique capabilities in low energy neutrino interaction measurements.

Soderberg, M.

2009-10-01T23:59:59.000Z

419

Characterization of a Site-Directed Mutant of Cytochrome b5 Designed To Alter Axial Imidazole Ligand Plane Orientation  

Science Journals Connector (OSTI)

After several refinement cycles using redundant dihedral restraint procedures (i.e., REDAC refinement; Güntert et al., 1991), it was apparent that the N? nitrogen of H63 was the axial ligand to the iron (e.g., Fe?N distances ranged from 1.9 to 2.2 Ĺ), and we included this as the restraint for both wild-type and mutant proteins. ...

Siddhartha Sarma; Bindi Dangi; ChunHua Yan; Russell J. DiGate; D. L. Banville; R. D. Guiles

1997-05-13T23:59:59.000Z

420

Axial and transverse acoustic radiation forces on a fluid sphere placed arbitrarily in Bessel beam standing wave tweezers  

SciTech Connect (OSTI)

The axial and transverse radiation forces on a fluid sphere placed arbitrarily in the acoustical field of Bessel beams of standing waves are evaluated. The three-dimensional components of the time-averaged force are expressed in terms of the beam-shape coefficients of the incident field and the scattering coefficients of the fluid sphere using a partial-wave expansion (PWE) method. Examples are chosen for which the standing wave field is composed of either a zero-order (non-vortex) Bessel beam, or a first-order Bessel vortex beam. It is shown here, that both transverse and axial forces can push or pull the fluid sphere to an equilibrium position depending on the chosen size parameter ka (where k is the wave-number and a the sphere’s radius). The corresponding results are of particular importance in biophysical applications for the design of lab-on-chip devices operating with Bessel beams standing wave tweezers. Moreover, potential investigations in acoustic levitation and related applications in particle rotation in a vortex beam may benefit from the results of this study. -- Highlights: •The axial and transverse forces on a fluid sphere in acoustical Bessel beams tweezers are evaluated. •The attraction or repulsion to an equilibrium position in the standing wave field is examined. •Potential applications are in particle manipulation using standing waves.

Mitri, F.G., E-mail: mitri@chevron.com

2014-03-15T23:59:59.000Z

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421

Octet-baryon axial-vector charges and SU(3)-breaking effects in the semileptonic hyperon decays  

E-Print Network [OSTI]

The octet-baryon axial-vector charges and the g1/f1 ratios measured in the semileptonic hyperon decays are studied up to O(p^3) using the covariant baryon chiral perturbation theory with explicit decuplet contributions. We clarify the role of different low-energy constants and find a good convergence for the chiral expansion of the axial-vector charges of the baryon octet, g1(0), with O(p^3) corrections typically around 20% of the leading ones. This is a consequence of strong cancellations between different next-to-leading order terms. We show that considering only non-analytic terms is not enough and that analytic terms appearing at the same chiral order play an important role in this description. The same effects still hold for the chiral extrapolation of the axial-vector charges and result in a rather mild quark-mass dependence. As a result, we report a determination of the leading order chiral couplings, D=0.623(61)(17) and F=0.441(47)(2), as obtained from a completely consistent chiral analysis up to O(p...

Ledwig, T; Geng, L S; Vacas, M J Vicente

2014-01-01T23:59:59.000Z

422

Operation of a test bed axial-gap brushless dc rotor with a superconducting stator  

SciTech Connect (OSTI)

A variable-speed axial-gap motor with a stator consisting of four liquid helium cooled superconducting electromagnets (two pole pairs) was built and proof tested up to 608 rpm in November 1990 as a tool for joint industry-laboratory evaluation of coils fabricated from high-temperature oxide superconductors. A second rotor was fabricated with improved materia winding configuration, and wire type, and the drive system was modified to eliminate current spiking. The modified motor was characterized to design speed, 188 rad/s (1800 rpm), to acquire a performance baseline for future comparison with that of high-temperature superconducting (HIS) wire. As it becomes commercially available, HTS wire will replace the low-temperature electromagnet wire in a stator modified to control wire temperatures between 4 K and 77 K. Measurements of the superconducting electromagnetic field and locked rotor torque as functions of cryocurrent and dc current through two phases of the rotor, respectively, provided data to estimate power that could be developed by the rotor. Back emf and parasitic mechanical and electromagnetic drag torques were measured as functions of angular velocity to calculate actual rotor power developed and to quantify losses, which reduce the motor`s efficiency. A detailed measurement of motor power at design speed confirmed the developed power equation. When subsequently operated at the 33-A maximum available rotor current, the motor delivered 15.3 kill (20.5 hp) to the load. In a final test, the cryostat was operated at 2500 A, 200 A below its critical current. At rotor design current of 60 A and 2500 A stator current, the extrapolated developed power would be 44.2 kill (59.2 hp) with 94% efficiency.

McKeever, J.W.; Sohns, C.W.; Schwenterly, S.W.; Young, R.W. Sr.; Campbell, V.W.; Hickey, M.H.; Ott, G.W. [Oak Ridge National Lab., TN (United States); Bailey, J.M. [Tennessee Univ., Knoxville, TN (United States)

1993-08-01T23:59:59.000Z

423

A patient-specific quality assurance study on absolute dose verification using ionization chambers of different volumes in RapidArc treatments  

SciTech Connect (OSTI)

The recalculation of 1 fraction from a patient treatment plan on a phantom and subsequent measurements have become the norms for measurement-based verification, which combines the quality assurance recommendations that deal with the treatment planning system and the beam delivery system. This type of evaluation has prompted attention to measurement equipment and techniques. Ionization chambers are considered the gold standard because of their precision, availability, and relative ease of use. This study evaluates and compares 5 different ionization chambers: phantom combinations for verification in routine patient-specific quality assurance of RapidArc treatments. Fifteen different RapidArc plans conforming to the clinical standards were selected for the study. Verification plans were then created for each treatment plan with different chamber-phantom combinations scanned by computed tomography. This includes Medtec intensity modulated radiation therapy (IMRT) phantom with micro-ionization chamber (0.007 cm{sup 3}) and pinpoint chamber (0.015 cm{sup 3}), PTW-Octavius phantom with semiflex chamber (0.125 cm{sup 3}) and 2D array (0.125 cm{sup 3}), and indigenously made Circular wax phantom with 0.6 cm{sup 3} chamber. The measured isocenter absolute dose was compared with the treatment planning system (TPS) plan. The micro-ionization chamber shows more deviations when compared with semiflex and 0.6 cm{sup 3} with a maximum variation of -4.76%, -1.49%, and 2.23% for micro-ionization, semiflex, and farmer chambers, respectively. The positive variations indicate that the chamber with larger volume overestimates. Farmer chamber shows higher deviation when compared with 0.125 cm{sup 3}. In general the deviation was found to be <1% with the semiflex and farmer chambers. A maximum variation of 2% was observed for the 0.007 cm{sup 3} ionization chamber, except in a few cases. Pinpoint chamber underestimates the calculated isocenter dose by a maximum of 4.8%. Absolute dose measurements using the semiflex ionization chamber with intermediate volume (0.125 cm{sup 3}) shows good agreement with the TPS calculated among the detectors used in this study. Positioning is very important when using smaller volume chambers because they are more sensitive to geometrical errors within the treatment fields. It is also suggested to average the dose over the sensitive volume for larger-volume chambers. The ionization chamber-phantom combinations used in this study can be used interchangeably for routine RapidArc patient-specific quality assurance with a satisfactory accuracy for clinical practice.

Syam Kumar, S.A., E-mail: skppm@rediffmail.com [Department of Medical Physics, Cancer Institute (WIA), Adyar, Chennai, Tamil Nadu (India); Sukumar, Prabakar; Sriram, Padmanaban; Rajasekaran, Dhanabalan; Aketi, Srinu; Vivekanandan, Nagarajan [Department of Medical Physics, Cancer Institute (WIA), Adyar, Chennai, Tamil Nadu (India)

2012-01-01T23:59:59.000Z

424

Progress on an integrated multi-physics simulation predictive capability for plasma chamber nuclear components  

SciTech Connect (OSTI)

Understanding the behavior of a plasma chamber component in the fusion environment requires a simulation technique that is capable of integrating multi-disciplinary computational codes while appropriately treating geometric heterogeneity and complexity. Such a tool should be able to interpret phenomena from mutually dependent scientific disciplines and predict performance with sufficient accuracy and consistency. Integrated multi-physics simulation predictive capability (ISPC) relies upon advanced numerical simulation techniques and is being applied to ITER first wall/shield and Test Blanket Module (TBM) designs. In this paper, progress in ISPC development is described through the presentation of a number of integrated simulations. The simulations cover key physical phenomena encountered in a fusion plasma chamber system, including tritium permeation, fluid dynamics, and structure mechanics. Interface engines were developed in order to pass field data, such as surface deformation or nuclear heating rate, from the structural analysis to the thermo-fluid MHD analysis code for magnetohydrodynamic (MHD) velocity profile assessments, or from the neutronics analysis to the thermo-fluid analysis for temperature calculations, respectively. Near-term effort toward further ISPC development is discussed.

A. Ying; M. Abdou; H. Zhang; R. Munipalli; M. Ulrickson; M. Sawan; B. Merrill

2010-12-01T23:59:59.000Z

425

Neutron/gamma dose separation by the multiple-ion-chamber technique  

SciTech Connect (OSTI)

Many mixed n/..gamma.. dosimetry systems rely on two dosimeters, one composed of a tissue-equivalent material and the other made from a non-hydrogenous material. The paired chamber technique works well in fields of neutron radiation nearly identical in spectral composition to that in which the dosimeters were calibrated. However, this technique is drastically compromised in phantom due to the degradation of the neutron spectrum. The three-dosimeter technique allows for the fall-off in neutron sensitivity of the two non-hydrogenous dosimeters. Precise and physically meaningful results were obtained with this technique with a D-T source in air and in phantom and with simultaneous D-T neutron and /sup 60/Co gamma ray irradiation in air. The MORSE-CG coupled n/..gamma.. three-dimensional Monte Carlo code was employed to calculate neutron and gamma doses in a water phantom. Gamma doses calculated in phantom with this code were generally lower than corresponding ion chamber measurements. This can be explained by the departure of irradiation conditions from ideal narrow-beam geometry. 97 references.

Goetsch, S.J.

1983-01-01T23:59:59.000Z

426

Binary reconstruction of the heart chambers from biplane angiographic image sequences  

SciTech Connect (OSTI)

The aim of this work is the three-dimensional (3-D) reconstruction of the left or right heart chamber from digital biplane angiograms. The approach used, the binary reconstruction, exploits the density information of subtracted ventriculograms from two orthogonal views in addition to the ventricular contours. The ambiguity of the problem is largely reduced by incorporating a priori knowledge of human ventricles. A model-based reconstruction program is described that is applicable to routinely acquired biplane ventriculographic studies. Prior to reconstruction, several geometric and densitometric imaging errors are corrected. The finding of corresponding density profiles and anatomical landmarks is supported by a biplane image pairing procedure that takes the movement of the gantry system into account. Absolute measurements are based on geometric isocenter calibration and a slice-wise density calibration technique. The reconstructed ventricles allow 3-D visualization and regional wall motion analysis independently of the gantry setting. The method is applied to clinical angiograms and tested in left- and right-ventricular phantoms yielding a well shape conformity even with few model information. The results indicate that volumes of binary reconstructed ventricles are less projection-dependent compared to volume data derived by purely contour-based methods. A limitations is that the heart chamber must not be superimposed by other dye-filled structures in both projections.

Prause, G.P.M.; Onnasch, D.G.W. [Univ. of Kiel (Germany). Clinic of Pediatric Cardiology] [Univ. of Kiel (Germany). Clinic of Pediatric Cardiology

1996-08-01T23:59:59.000Z

427

Multinuclear and multidimensional solid-state NMR investigations of combustion chamber deposits  

SciTech Connect (OSTI)

Multinuclear solid-state NMR has been used to study the carbonaceous backbone of combustion chamber deposits (CCDs) generated in both gasoline and diesel engines. The combination of {sup 1}H-{sup 13}C cross-polarization, and dipolar dephasing techniques have been used to {open_quotes}average molecule{close_quotes} parameters for a large number of CCDs. These parameters were correlated with gasoline composition and cylinder cleanliness. Discussion will be presented on deposits from different areas of the chamber - piston top, cylinder head, squish, non-squish, end-gas, non-end gas regions. Deposits from various cylinders in a number of dynamometer engines, fleet car engines will be compared. The use of NMR to observe the effects of bench-test engine modifications on CCD structure will be demonstrated. The macromolecular structure of the deposits was studied by {sup 13}C-{sup 13}C spin-exchange experiments which allow one to observe internuclear dipolar interactions between the various carbon functionalities in the deposit. The spatial information on fuel additive - CCD interactions that these experiments provide will be discussed.

Edwards, J.C. [Texaco Research Center, Beacon, NY (United States)

1996-10-01T23:59:59.000Z

428

Electrical optimization of plasma-enhanced chemical vapor deposition chamber cleaning plasmas  

Science Journals Connector (OSTI)

Fluorinated gas discharges are widely used by the semiconductor industry in etching and chamber cleaning applications but the performance of these discharges varies in unpredictable ways for unknown reasons believed to be electrical in origin. To investigate possible mechanisms for this behavior we have measured the electrical characteristics of NF 3 /Ar CF 4 /O 2 /Ar and C 2 F 6 /O 2 /Ar chamber cleaning plasmas at 6.7–267 Pa in a 13.56 MHz capacitively coupled parallel-plate reactor using radio-frequency current and voltage probes and optical emission spectroscopy. From the measurements power losses in the external circuitry surrounding the discharge were determined. Furthermore using the measurements and equivalent circuit models the mechanisms by which power was absorbed within the discharge itself were investigated. Power was absorbed most efficiently at particular values of the discharge impedance. These optimal impedances occur in the middle of a transition from capacitive impedances at low pressures to resistive impedances at high pressures. These results illustrate that the plasma impedance is a useful parameter for monitoring and optimizing plasma processes in highly electronegative gases.

M. A. Sobolewski; J. G. Langan; B. S. Felker

1998-01-01T23:59:59.000Z

429

Photoelectron track length distributions measured in a negative ion time projection chamber  

E-Print Network [OSTI]

We report photoelectron track length distributions between 3 and 8 keV in gas mixtures of Ne+CO2+CH3NO2 (260:80:10 Torr) and CO2+CH3NO2 (197.5: 15 Torr). The measurements were made using a negative ion time projection chamber (NITPC) at the National Synchrotron Light Source (NSLS) at the Brookhaven National Laboratory (BNL). We report the first quantitative analysis of photoelectron track length distributions in a gas. The distribution of track lengths at a given energy is best fit by a lognormal distribution. A powerlaw distribution of the form, f(E)=a(E/Eo)n, is found to fit the relationship between mean track length and energy. We find n=1.29 +/- 0.07 for Ne+CO2+CH3NO2 and n=1.20 +/- 0.09 for CO2+CH3NO2. Understanding the distribution of photoelectron track lengths in proportional counter gases is important for optimizing the pixel size and the dimensions of the active region in electron-drift time projection chambers (TPCs) and NITPC X-ray polarimeters.

Prieskorn, Z R; Kaaret, P E; Black, J K

2014-01-01T23:59:59.000Z

430

Design and Construction of Large Size Micromegas Chambers for the ATLAS Upgrade of the Muon Spectrometer  

E-Print Network [OSTI]

Large area Micromegas detectors will be employed fo r the first time in high-energy physics experiments. A total surface of about 150 m$^2$ of the forward regions of the Muon Spectrometer of the ATLAS detector at LHC will be equipped with 8-layer Micromegas modules. Each module extends over a surface from 2 to 3 m$^2$ for a total active area of 1200 m$^2$. Together with the small strip Thin Gap Chambers they will compose the two New Small Wheels, which will replace the innermost stations of the ATLAS endcap muon tracking system in the 2018/19 shutdown. In order to achieve a 15% transverse momentum resol ution for 1 TeV muons, in addition to an excellent intrinsic resolution, the mechanical prec ision of each plane of the assembled module must be as good as 30 $\\mu$m along the precision coordi nate and 80 $\\mu$m perpendicular to the chamber. The design and construction procedure of the microm egas modules will be presented, as well as the design for the assembly of modules onto the New Small Wheel. Emphasis wi...

Losel, Philipp Jonathan; The ATLAS collaboration

2014-01-01T23:59:59.000Z

431

Quality assurance of proton beams using a multilayer ionization chamber system  

SciTech Connect (OSTI)

Purpose: The measurement of percentage depth-dose (PDD) distributions for the quality assurance of clinical proton beams is most commonly performed with a computerized water tank dosimetry system with ionization chamber, commonly referred to as water tank. Although the accuracy and reproducibility of this method is well established, it can be time-consuming if a large number of measurements are required. In this work the authors evaluate the linearity, reproducibility, sensitivity to field size, accuracy, and time-savings of another system: the Zebra, a multilayer ionization chamber system.Methods: The Zebra, consisting of 180 parallel-plate ionization chambers with 2 mm resolution, was used to measure depth-dose distributions. The measurements were performed for scattered and scanned proton pencil beams of multiple energies delivered by the Hitachi PROBEAT synchrotron-based delivery system. For scattered beams, the Zebra-measured depth-dose distributions were compared with those measured with the water tank. The principal descriptors extracted for comparisons were: range, the depth of the distal 90% dose; spread-out Bragg peak (SOBP) length, the region between the proximal 95% and distal 90% dose; and distal-dose fall off (DDF), the region between the distal 80% and 20% dose. For scanned beams, the Zebra-measured ranges were compared with those acquired using a Bragg peak chamber during commissioning.Results: The Zebra demonstrated better than 1% reproducibility and monitor unit linearity. The response of the Zebra was found to be sensitive to radiation field sizes greater than 12.5 × 12.5 cm; hence, the measurements used to determine accuracy were performed using a field size of 10 × 10 cm. For the scattered proton beams, PDD distributions showed 1.5% agreement within the SOBP, and 3.8% outside. Range values agreed within ?0.1 ± 0.4 mm, with a maximum deviation of 1.2 mm. SOBP length values agreed within 0 ± 2 mm, with a maximum deviation of 6 mm. DDF values agreed within 0.3 ± 0.1 mm, with a maximum deviation of 0.6 mm. For the scanned proton pencil beams, Zebra and Bragg peak chamber range values demonstrated agreement of 0.0 ± 0.3 mm with a maximum deviation of 1.3 mm. The setup and measurement time for all Zebra measurements was 3 and 20 times less, respectively, compared to the water tank measurements.Conclusions: Our investigation shows that the Zebra can be useful not only for fast but also for accurate measurements of the depth-dose distributions of both scattered and scanned proton beams. The analysis of a large set of measurements shows that the commonly assessed beam quality parameters obtained with the Zebra are within the acceptable variations specified by the manufacturer for our delivery system.

Dhanesar, Sandeep; Sahoo, Narayan; Kerr, Matthew; Taylor, M. Brad; Summers, Paige; Zhu, X. Ronald; Poenisch, Falk; Gillin, Michael [Department of Radiation Physics and Proton Therapy Center, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 94, Houston, Texas 77030 (United States) [Department of Radiation Physics and Proton Therapy Center, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 94, Houston, Texas 77030 (United States); Department of Radiation Physics and Proton Therapy Center, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 94, Houston, Texas 77030 and The University of Texas at Houston Graduate School of Biomedical Sciences, 6767 Bertner Avenue, S3.8344, Houston, Texas 77030 (United States); Department of Radiation Physics and Proton Therapy Center, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 94, Houston, Texas 77030 (United States); Department of Radiation Physics and Proton Therapy Center, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 94, Houston, Texas 77030 and The University of Texas at Houston Graduate School of Biomedical Sciences, 6767 Bertner Avenue, S3.8344, Houston, Texas 77030 (United States)

2013-09-15T23:59:59.000Z

432

Ultrahigh speed 1050nm swept source / Fourier domain OCT retinal and anterior segment imaging at 100,000 to 400,000 axial scans per second  

E-Print Network [OSTI]

We demonstrate ultrahigh speed swept source/Fourier domain ophthalmic OCT imaging using a short cavity swept laser at 100,000 – 400,000 axial scan rates. Several design configurations illustrate tradeoffs in imaging speed, ...

Potsaid, Benjamin M.

433

A Novel Approach to the Design of an In-Wheel Semi-Anhysteretic Axial-Flux Switched-Reluctance Motor Drive System for Electric Vehicles .  

E-Print Network [OSTI]

??This thesis presents the development of an in-wheel drive system consisting of an axial-flux switched-reluctance motor and a hub suspension. The motor is designed using… (more)

Lambert, Tim

2013-01-01T23:59:59.000Z

434

Hybrid experimental-numerical determination of the loading path to fracture in TRIP780 sheets subjected to multi-axial loading  

E-Print Network [OSTI]

The development of ductile fracture models of metals requires reliable measurements of the stress and strain histories up to the onset of fracture in multi-axial experiments. In the present work, a hybrid experimental-numerical ...

Dunand, Matthieu

2010-01-01T23:59:59.000Z

435

Extraction of depth-dependent perturbation factors for parallel-plate chambers in electron beams using a plastic scintillation detector  

SciTech Connect (OSTI)

Purpose: This work presents the experimental extraction of the overall perturbation factor P{sub Q} in megavoltage electron beams for NACP-02 and Roos parallel-plate ionization chambers using a plastic scintillation detector (PSD). Methods: The authors used a single scanning PSD mounted on a high-precision scanning tank to measure depth-dose curves in 6, 12, and 18 MeV clinical electron beams. The authors also measured depth-dose curves using the NACP-02 and PTW Roos chambers. Results: The authors found that the perturbation factors for the NACP-02 and Roos chambers increased substantially with depth, especially for low-energy electron beams. The experimental results were in good agreement with the results of Monte Carlo simulations reported by other investigators. The authors also found that using an effective point of measurement (EPOM) placed inside the air cavity reduced the variation of perturbation factors with depth and that the optimal EPOM appears to be energy dependent. Conclusions: A PSD can be used to experimentally extract perturbation factors for ionization chambers. The dosimetry protocol recommendations indicating that the point of measurement be placed on the inside face of the front window appear to be incorrect for parallel-plate chambers and result in errors in the R{sub 50} of approximately 0.4 mm at 6 MeV, 1.0 mm at 12 MeV, and 1.2 mm at 18 MeV.

Lacroix, Frederic; Guillot, Mathieu; McEwen, Malcolm; Cojocaru, Claudiu; Gingras, Luc; Beddar, A. Sam; Beaulieu, Luc [Departement de Radio-Oncologie, Centre hospitalier de l'Universite de Montreal (CHUM), 1560 Sherbrooke Est, Montreal, Quebec H2L 4M1 (Canada) and Departement de Physique, Universite de Montreal, Pavillon Roger-Gaudry (D-428), 2900 Boul. Edouard-Montpetit, Montreal, Quebec H3T 1J4 (Canada); Departement de Physique, de Genie Physique et d'Optique, Universite Laval, Quebec, Quebec G1K 7P4 (Canada) and Departement de Radio-Oncologie, Ho circumflex tel-Dieu de Quebec, Centre hospitalier Universitaire de Quebec (CHUQ), Quebec, Quebec G1R 2J6 (Canada); Ionizing Radiation Standards, Institute for National Measurement Standards, National Research Council (NRC), Ottawa, Ontario K1A 0R6 (Canada); Departement de Physique, de Genie Physique et d'Optique, Universite Laval, Quebec, Quebec G1K 7P4 (Canada) and Departement de Radio-Oncologie, Ho circumflex tel-Dieu de Quebec, Centre hospitalier Universitaire de Quebec (CHUQ), Quebec, Quebec G1R 2J6 (Canada); Department of Radiation Physics, Unit 94, University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030 (United States); Departement de Physique, de Genie Physique et d'Optique, Universite Laval, Quebec, Quebec G1K 7P4 (Canada) and Departement de Radio-Oncologie, Hotel-Dieu de Quebec, Centre hospitalier Universitaire de Quebec (CHUQ), Quebec, Quebec G1R 2J6 (Canada)

2010-08-15T23:59:59.000Z

436

U.S. Chamber of Commerce's 4th Annual North America Forum | Department of  

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

Commerce's 4th Annual North America Forum Commerce's 4th Annual North America Forum U.S. Chamber of Commerce's 4th Annual North America Forum June 16, 2008 - 1:30pm Addthis Remarks As Prepared for Delivery for Secretary Bodman Thank you very much, Ron, for that kind introduction and for the critically important work that you and your colleagues do at Lawrence Livermore. I also want to thank my good friend Secretary George Shultz - along with his esteemed co-chairs for this event, Peter Lougheed and Pedro Aspe, for inviting me to be with you. It's a pleasure to be here. The way I see it, this event could not come at a better time. With its focus on enhancing cooperation among the United States, Canada and Mexico - and on bringing together representatives of our governments and the private sector - you are helping to develop and achieve real and lasting solutions

437

Performance of a Chamber for Studying the Liquid Xenon Response to Nuclear Recoils  

E-Print Network [OSTI]

The design and performance of a 1.2 liter liquid xenon chamber equipped with 7 two-inch photomultiplier tubes, with the purpose of studying the scintillation response of xenon to gamma-rays and neutrons, is described. Measurements with gamma-rays indicate a high VUV light collection efficiency resulting in ~5.5 photoelectrons per 1 keV of deposited energy. The energy resolution (FWHM) is 18% and 22%, for 122 keV and 511 keV gamma-rays, respectively. An algorithm for the reconstruction of the scintillation coordinates in (x,y) plane was developed and tested. The position resolution is estimated to be 6.9 mm (sigma) for 122 keV gamma-rays.

V. Chepel; F. Neves; V. Solovov; A. Pereira; M. I. Lopes; J. Pinto da Cunha; P. Mendes; A. Lindote; C. P. Silva; R. Ferreira Marques; A. J. P. L. Policarpo

2005-01-07T23:59:59.000Z

438

Environmental chamber measurements of mercury flux from coal utilization by-products  

SciTech Connect (OSTI)

An environmental chamber was constructed to measure the mercury flux from coal utilization by-product (CUB) samples. Samples of fly ash, FGD gypsum, and wallboard made from FGD gypsum were tested under both dark and illuminated conditions with or without the addition of water to the sample. Mercury releases varied widely, with 7-day experiment averages ranging from -6.8 to 73 ng/m2 h for the fly ash samples and -5.2 to 335 ng/m2 h for the FGD/wallboard samples. Initial mercury content, fly ash type, and light exposure had no observable consistent effects on the mercury flux. For the fly ash samples, the effect of a mercury control technology was to decrease the emission. For three of the four pairs of FGD gypsum and wallboard samples, the wallboard sample released less (or absorbed more) mercury than the gypsum.

Pekney, N.J.; Martello, D.V.; Schroeder, K.T.; Granite, E.J.

2009-05-01T23:59:59.000Z

439

Performance of a Large Area Avalanche Photodiode in a Liquid Xenon Ionization and Scintillation Chamber  

E-Print Network [OSTI]

Scintillation light produced in liquid xenon (LXe) by alpha particles, electrons and gamma-rays was detected with a large area avalanche photodiode (LAAPD) immersed in the liquid. The alpha scintillation yield was measured as a function of applied electric field. We estimate the quantum efficiency of the LAAPD to be 45%. The best energy resolution from the light measurement at zero electric field is 7.5%(sigma) for 976 keV internal conversion electrons from Bi-207 and 2.6%(sigma) for 5.5 MeV alpha particles from Am-241. The detector used for these measurements was also operated as a gridded ionization chamber to measure the charge yield. We confirm that using a LAAPD in LXe does not introduce impurities which inhibit the drifting of free electrons.

K. Ni; E. Aprile; D. Day; K. L. Giboni; J. A. M. Lopes; P. Majewski; M. Yamashita

2005-02-14T23:59:59.000Z

440

Design, Fabrication, and Application of a Dynamic Chamber for Measuring Gas Emissions from Soil  

Science Journals Connector (OSTI)

Accurate measurement of the emission of trace gases and VOCs from soils to the atmosphere is essential for studying the behavior of gas movement and its fate in the subsurface, for evaluating existing theories and models of trace gas and VOC emissions, for estimating masses of trace gases and VOCs emitted into the atmosphere, and thus, for assessing the effects of such emissions upon the environment. ... (6) The outside surface of the chamber should be able to reflect solar radiation so that the radiant heating or the “greenhouse” effect can be effectively reduced. ... This flow rate was monitored every 1 s using a turbine-wheel gas flow sensor (McMillan Co., Georgetown, TX), averaged over a 5-min interval and recorded by an on-site computer. ...

Fang Gao; S. R. Yates; M. V. Yates; Jianying Gan; F. F. Ernst

1996-12-30T23:59:59.000Z

Note: This page contains sample records for the topic "axial magma chamber" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Microbial Community Analysis of a Single Chamber Microbial Fuel Cell Using Potato Wastewater  

SciTech Connect (OSTI)

Microbial fuel cells (MFCs) convert chemical energy to electrical energy via bioelectrochemical reactions mediated by microorganisms. We investigated the diversity of the microbial community in an air cathode single chamber MFC that utilized potato-process wastewater as substrate. Terminal Restriction Fragment Length Polymorphism (T-RFLP) results indicated that the bacterial communities on the anode, cathode, control electrode, and MFC bulk fluid were similar, but differed dramatically from that of the anaerobic domestic sludge and potato wastewater inoculum. The 16S rDNA sequencing results showed that microbial species detected on the anode were predominantly within the phyla of Proteobacteria, Firmicutes, and Bacteroidetes. Fluorescent microscopy results indicated that there was a clear enhancement of biofilm formation on the anode. Results of this study could help improve understanding of the complexity of microbial communities and optimize the microbial composition for generating electricity by MFCs that utilize potato wastewater.

Zhen Li; Rishika Haynes; Eugene Sato; Malcolm Shields; Yoshiko Fujita; Chikashi Sato

2014-04-01T23:59:59.000Z

442

Proposal for the award of a blanket purchase contract, without competitive tendering, for the supply of pressurised ionisation chambers for radiation monitoring  

E-Print Network [OSTI]

Proposal for the award of a blanket purchase contract, without competitive tendering, for the supply of pressurised ionisation chambers for radiation monitoring

2013-01-01T23:59:59.000Z

443

Usiing NovoCOS cleaning equipment in repairing the furnace-chamber lining in coke batteries 4 & 5 at OAO Koks  

SciTech Connect (OSTI)

Experience with a new surface-preparation technology for the ceramic resurfacing of the refractory furnace-chamber lining in coke batteries is described.

S.G. Protasov; R. Linden; A. Gross [OAO Koks, Kemerovo (Russian Federation)

2009-05-15T23:59:59.000Z

444

A sonic spark chamber system with on-line computation for studying the reaction $\\pi^{-} + p -> f^{0} + n$ at 3 GeV/c  

E-Print Network [OSTI]

A sonic spark chamber system with on-line computation for studying the reaction $\\pi^{-} + p -> f^{0} + n$ at 3 GeV/c

Bird, L; West, D; Whitehead, G; Wood, E; Crabb, D G; Hutchinson, G W; McEwen, J G; Ott, R; Aitken, D; Hague, J; Jennings, R; Parsons, A J; Auld, E G

1964-01-01T23:59:59.000Z

445

Posterior chamber phakic intraocular lens to correct myopia: Long-term follow-up  

Science Journals Connector (OSTI)

Purpose To evaluate the long-term safety and efficacy of a refractive phakic intraocular lens (pIOL) (PRL) to correct moderate to high myopia. Setting Department of Ophthalmology, University Medicine Charité Berlin, Berlin, Germany. Design Retrospective cohort study. Methods Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, intraocular pressure, endothelial cell loss, and adverse events were evaluated. Results The study enrolled 53 eyes (mean spherical equivalent [SE] ?12.17 diopters [D] ± 4.12 [SD]) of 29 patients. The mean age was 34.6 ± 9.2 years and the mean follow-up, 86 ± 21.2 months. The mean UDVA improved from 1.37 ± 0.28 logMAR preoperatively to 0.14 ± 0.19 logMAR at the last postoperative visit (P<.05). The mean CDVA improved from 0.10 ± 0.18 logMAR to ?0.01 ± 0.09 logMAR (P<.05). The overall mean efficacy index and mean safety index were 0.9 and 1.21, respectively, at the last follow-up visit. The mean endothelial cell loss at the last follow-up was 6.4%. The complications were slight posterior chamber (PC) pIOL decentration (5 eyes, 9.4%), severe PC pIOL decentration resulting in pIOL removal (1 eye, 1.8%), glaucoma (4 eyes, 7.5%), clinically significant cortical lens opacification resulting in cataract surgery (4 eyes, 7.5%), clinically asymptomatic anterior subcapsular cataract formation (6 eyes, 11.3%), and retinal detachment (2 eyes, 3.8%). Conclusions Posterior chamber phakic pIOL implantation to correct moderate to high myopia provided predictable and stable refractive results but with a high rate of serious complications over the long term. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Necip Torun; Eckart Bertelmann; Matthias K.J. Klamann; Anna-Karina Maier; Anja Liekfeld; Johannes Gonnermann

2013-01-01T23:59:59.000Z

446

Evidence and mechanisms of axial-radiation asymmetry in dynamic hohlraums driven by wire-array Z pinches  

SciTech Connect (OSTI)

Dynamic hohlraums driven by arrays consisting of large numbers of tungsten wires in Z pinches exhibit differences in radiation emitted from REHs (radiation exit holes) symmetrically located at either end of the hohlraum [Sanford et al., Phys. Plasmas 10, 1187 (2003)]. Significantly greater peak power is radiated from the top (anode) REH relative to the bottom (cathode) REH. Spectral measurements of tungsten M-shell emission (2-2.4 keV) indicate the peak radiated power from either REH anticorrelates with the fraction of wire-array tungsten plasma inferred to sweep across (or into the field of view of) the REH near the time of peak axial emission. In all cases, greater M-shell emission relative to the total emission in the band 1.4-4 keV is measured at the bottom REH in comparison to the top REH. The decrease in peak power radiated from the bottom REH relative to the top appears to be due, in part, to an increase in localized opacity arising from the presence of increased wire-array tungsten plasma near the bottom REH. The asymmetry in both peak axial power and pulse shape is largely removed by adding two thin annular pedestals extending 3 mm into the anode-cathode gap from either electrode, just radially outboard of the REHs. The pedestals are designed to prevent the radial flow of tungsten plasma from prematurely crossing the REHs. A polarity effect [Sarkisov et al., Phys. Rev. E 66, 046413(6) (2002)] during wire initiation may offer one possible explanation for the underlying cause of such a tungsten-related axial power asymmetry.

Sanford, T.W.L.; Nash, T.J.; Mock, R.C.; Peterson, D.L.; Watt, R.G.; Chrien, R.E.; Apruzese, J.P.; Clark, R.W.; Roderick, N.F.; Sarkisov, G.S.; Haines, M.G. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Naval Research Laboratory, Washington, DC 20375 (United States); University of New Mexico, Albuquerque, New Mexico 87131 (United States); Ktech Corporation, Albuquerque, 1030 Eubank Boulevard, Albuquerque, New Mexico 87123 (United States); Blackett Laboratory, Imperial College, London SW7 2BZ (United Kingdom)

2005-02-01T23:59:59.000Z

447

Experiments with all-Kapton insulation and axial prestress in 1. 8 m-long SSC R D magnets  

SciTech Connect (OSTI)

Several 1.8 m-long magnets have been built to evaluate possible variations in the design of the SSC collider dipoles. Except for length and the parameters being tested, these models have the features of 40 mm aperture collider dipoles, which are based on a two-layer cosine theta coil. In these magnets, we have tested all-Kapton cable insulation and the effects of changes in the axial coil prestress. Construction details and test results for quenching, field harmonics, and coil loading are reported. 5 refs., 7 figs.

Wanderer, P.; Anerella, M.; Cottingham, G.; Ganetis, G.; Garber, M.; Ghosh, A.; Greene, A.; Gupta, R.; Herrera, J.; Kahn, S.; Kelly, E.; Meade, A.; Morgan, G.; Muratore, J.; Prodell, A.; Rehak, M.; Rohrer, E.; Sampson, W.; Shutt, R.; Thompson, P.; Willen, E. (Brookhaven National Lab., Upton, NY (USA)); Goodzeit, C.; Radusewicz, P. (Superconducting Super Collider Lab., Dallas, TX (USA))

1991-01-01T23:59:59.000Z

448

The Cretaceous Okhotsk–Chukotka Volcanic Belt (NE Russia): Geology, geochronology, magma output rates, and implications on the genesis of silicic \\{LIPs\\}  

Science Journals Connector (OSTI)

The Cretaceous Okhotsk–Chukotka volcanic belt (OCVB) is a prominent subduction-related magmatic province, having the remarkably high proportion of silicic rocks (ca. 53% of the present-day crop area, and presumably over 70% of the total volcanic volume). Its estimated total extrusive volume ranges between 5.5 × 105 km3 (the most conservative estimate) and over 106 km3. This article presents a brief outline of the geology of OCVB, yet poorly described in international scientific literature, and results of a geochronological study on the northern part of the volcanic belt. On the base of new and published U–Pb and 40Ar/39Ar age determinations, a new chronological model is proposed. Our study indicates that the activity of the volcanic belt was highly discontinuous and comprised at least five main episodes at 106–98 Ma, 94–91 Ma, 89–87 Ma, 85.5–84 Ma, and 82–79 Ma. The new data allow a semi-quantitative estimate of the volcanic output rate for the observed part of the OCVB (area and volume approximately 105 km2 and 2.5 × 105 km3, respectively). The average extrusion rate for the entire lifetime of the volcanic belt ranges between 1.6 and 3.6 × 10? 5 km3yr? 1 km? 1, depending on the assumed average thickness of the volcanic pile; the optimal value is 2.6 × 10? 5 km3yr? 1 km? 1. Despite imprecise, such estimates infer the time-averaged volcanic productivity of the OCVB is similar to that of silicic \\{LIPs\\} and most active recent subduction-related volcanic areas of the Earth. However, the most extensive volcanic flare-ups at 89–87 and 85.5-84 Ma had higher rates of over 9.0 × 10? 5 km3yr? 1 km? 1. The main volumetric, temporal and compositional parameters of the OCVB are similar to those of silicic LIPs. This gives ground for discussion about the geodynamic setting of the latters, because the widely accepted definition of a LIP implies a strictly intraplate environment. Considering the genesis of the OCVB and other large provinces of silicic volcanism, we propose that residual thermal energy preserved in the continental crust after a previous major magmatic event may have been one of major reasons for high proportion of felsic rocks in a volcanic pile. In this scenario, underplating of mantle-derived basalts causes fast and extensive melting of still hot continental crust and generation of voluminous silicic magmas.

P.L. Tikhomirov; E.A. Kalinina; T. Moriguti; A. Makishima; K. Kobayashi; I.Yu. Cherepanova; E. Nakamura

2012-01-01T23:59:59.000Z

449

Effect of sweep gas composition on ionization chamber response in the BEATRIX-II tritium recovery experiment  

SciTech Connect (OSTI)

The BEATRIX-II irradiation experiment was an in situ tritium recovery experiment to evaluate the tritium release characteristics of fusion ceramic breeder materials and to characterize their stability under fast neutron irradiation to extended burnups. This is an International Energy Agency (IEA) sponsored experiment which is being carried out in the Materials Open Test Assembly of Fast Flux Test Facility (FFTF). The participants are Japan, Canada and the US The in situ tritium recovery experiment consisted of two individual in-reactor experimental assemblies (Phase I and Phase II) that were irradiated for 300 and 200 EFPD, respectively. Each experimental phase included two specimens: a thin annular specimen capable of temperature changes and a larger temperature-gradient specimen. In Phase I both specimens were Li{sub 2}O while for Phase II the temperature-change specimen consisted of Li{sub 2}O and the temperature-gradient specimen was a Li{sub 2}ZrO{sub 3} spherebed. Real-time measurements of the tritium release from the specimens during changing conditions (neutronics, temperature and sweep gas composition) were made using ion chambers. In order to correctly interpret the response of the ionization chambers it is necessary to understand the effect of changing sweep gas composition on the operation of the chambers. The purpose of this paper is to describe activities carried out to determine the effect of hydrogen additions to a helium sweep gas on the operation of these ionization chambers.

Slagle, O.D.; Hollenberg, G.W. [Pacific Northwest Lab., Richland, WA (United States); Baker, D.E. [Westinghouse Hanford Co., Richland, WA (United States)

1992-10-01T23:59:59.000Z

450

Effect of sweep gas composition on ionization chamber response in the BEATRIX-II tritium recovery experiment  

SciTech Connect (OSTI)

The BEATRIX-II irradiation experiment was an in situ tritium recovery experiment to evaluate the tritium release characteristics of fusion ceramic breeder materials and to characterize their stability under fast neutron irradiation to extended burnups. This is an International Energy Agency (IEA) sponsored experiment which is being carried out in the Materials Open Test Assembly of Fast Flux Test Facility (FFTF). The participants are Japan, Canada and the US The in situ tritium recovery experiment consisted of two individual in-reactor experimental assemblies (Phase I and Phase II) that were irradiated for 300 and 200 EFPD, respectively. Each experimental phase included two specimens: a thin annular specimen capable of temperature changes and a larger temperature-gradient specimen. In Phase I both specimens were Li[sub 2]O while for Phase II the temperature-change specimen consisted of Li[sub 2]O and the temperature-gradient specimen was a Li[sub 2]ZrO[sub 3] spherebed. Real-time measurements of the tritium release from the specimens during changing conditions (neutronics, temperature and sweep gas composition) were made using ion chambers. In order to correctly interpret the response of the ionization chambers it is necessary to understand the effect of changing sweep gas composition on the operation of the chambers. The purpose of this paper is to describe activities carried out to determine the effect of hydrogen additions to a helium sweep gas on the operation of these ionization chambers.

Slagle, O.D.; Hollenberg, G.W. (Pacific Northwest Lab., Richland, WA (United States)); Baker, D.E. (Westinghouse Hanford Co., Richland, WA (United States))

1992-10-01T23:59:59.000Z

451

2014 National Small Business Contracting Summit- US Women’s Chamber of Commerce & National Association of Small Business Contractors  

Broader source: Energy.gov [DOE]

The National Association of Small Business Contractors and the U.S. Women's Chamber of Commerce present the 2014 National Small Business Federal Contracting Summit. The event will include sessions on securing a fair share of federal contracting, legal issues, trends and opportunities.

452

A Geographic Redirection Service for On-line Games Chris Chambers Wu-chi Feng Wu-chang Feng  

E-Print Network [OSTI]

@OHSU {chambers,wuchi,wuchang}@cse.ogi.edu Debanjan Saha IBM Research dsaha@us.ibm.com ABSTRACT For many on Shooters, fre- quently utilize a widely distributed server model. For the most popular FPS at this time, Counter-Strike (a variant of Half-Life), there are more than 30,000 registered servers running at any

453

Status of axial heterogeneous liquid-metal fast breeder reactor core design studies and research and development  

SciTech Connect (OSTI)

The current status of axial heterogeneous core (AHC) design development in Japan, which consists of an AHC core design in a pool-type demonstration fast breeder reactor (DFBR) and research and development activities supporting AHC core design, is presented. The DFBR core design objectives developed by The Japan Atomic Power Company include (a) favorable core seismic response, (b) core compactness, (c) high availability, and (d) lower fuel cycle cost. The AHC concept was selected as a reference pool-type DFBR core because it met these objectives more suitably than the homogeneous core (HOC). The AHC core layouts were optimized emphasizing the reduction of the burnup reactivity swing, peak fast fluence, and power peaking. The key performance parameters resulting from the AHC, such as flat axial power/flux distribution, lower peak fast fluence, lower burnup reactivity swing, etc., were evaluated in comparison with the HOC. The critical experiments at the Japan Atomic Energy Research Institute's Fast Critical Assembly facility demonstrate the key AHC performance characteristics. The large AHC engineering benchmark experiments using the zero-power plutonium reactor and the AHC fuel pin irradiation test program using the JOYO reactor are also presented.

Nakagawa, H.; Inagaki, T.; Yoshimi, H.; Shirakata, K.; Watari, Y.; Suzuki, M.; Inoue, K.

1988-11-01T23:59:59.000Z

454

Exit blade geometry and part-load performance of small axial flow propeller turbines: An experimental investigation  

SciTech Connect (OSTI)

A detailed experimental investigation of the effects of exit blade geometry on the part-load performance of low-head, axial flow propeller turbines is presented. Even as these turbines find important applications in small-scale energy generation using micro-hydro, the relationship between the layout of blade profile, geometry and turbine performance continues to be poorly characterized. The experimental results presented here help understand the relationship between exit tip angle, discharge through the turbine, shaft power, and efficiency. The modification was implemented on two different propeller runners and it was found that the power and efficiency gains from decreasing the exit tip angle could be explained by a theoretical model presented here based on classical theory of turbomachines. In particular, the focus is on the behaviour of internal parameters like the runner loss coefficient, relative flow angle at exit, mean axial flow velocity and net tangential flow velocity. The study concluded that the effects of exit tip modification were significant. The introspective discussion on the theoretical model's limitation and test facility suggests wider and continued experimentation pertaining to the internal parameters like inlet vortex profile and exit swirl profile. It also recommends thorough validation of the model and its improvement so that it can be made capable for accurate characterization of blade geometric effects. (author)

Singh, Punit; Nestmann, Franz [Institute for Water and River Basin Management (IWG), University of Karlsruhe, Kaiser Str. 12, D 76128 Karlsruhe (Germany)

2010-09-15T23:59:59.000Z

455

A Concept for a Low Pressure Noble Gas Fill Intervention in the IFE Fusion Test Facility (FTF) Target Chamber  

SciTech Connect (OSTI)

An engineering evaluation has been initiated to investigate conceptual engineering methods for implementing a viable gas shield strategy in the Fusion Test Facility (FTF) target chamber. The employment of a low pressure noble gas in the target chamber to thermalize energetic helium ions prior to interaction with the wall could dramatically increase the useful life of the first wall in the FTF reactor1. For the purpose of providing flexibility, two target chamber configurations are addressed: a five meter radius sphere and a ten meter radius sphere. Experimental studies at Nike have indicated that a low pressure, ambient gas resident in the target chamber during laser pulsing does not appear to impair the ability of laser light from illuminating targets2. In addition, current investigations into delivering, maintaining, and processing low pressure gas appear to be viable with slight modification to current pumping and plasma exhaust processing technologies3,4. Employment of a gas fill solution for protecting the dry wall target chamber in the FTF may reduce, or possibly eliminate the need for other attenuating technologies designed for keeping He ions from implanting in first wall structures and components. The gas fill concept appears to provide an effective means of extending the life of the first wall while employing mostly commercial off the shelf (COTS) technologies. Although a gas fill configuration may provide a methodology for attenuating damage inflicted on chamber surfaces, issues associated with target injection need to be further analyzed to ensure that the gas fill concept is viable in the integrated FTF design5. In the proposed system, the ambient noble gas is heated via the energetic helium ions produced by target detonation. The gas is subsequently cooled by the chamber wall to approximately 800oC, removed from the chamber, and processed by the chamber gas processing system (CGPS). In an optimized scenario of the above stated concept, the chamber wall acts as the primary heat exchanger. During removal, gas is pumped through the laser ports by turbo molecular-drag pumps (TM-DP). For the purpose of reducing organic based lubricants and seals, a magnetically levitated TM-DP is being investigated with pump manufacturers. Currently, magnetically levitated turbo molecular pumps are commercially available. The pumps will be exposed to thermal loads and ionizing radiation (tritium, Ar-41, post detonation neutrons). Although the TM-DP's will be subjected to these various radiations, current designs for similar pumping devices have been hardened and have the ability of locating control electronics in remote radiation shielded enclosures4. The radiation hardened TM-DP's will be 5 required to operate with minimal maintenance for periods of up to 18 continuous months. As part of this initial investigation for developing a conceptual engineering strategy for a gas fill solution, commercial suppliers of low pressure gas pumping systems have been contacted and engaged in this evaluation. Current technology in the area of mechanical pumping systems indicates that the development of a robust pumping system to meet the requirements of the FTF gas fill concept is within the limits of COTS equipment3,4.

C.A. Gentile, W.R. Blanchard, T.A. Kozub, M. Aristova, C. McGahan, S. Natta, K. Pagdon, J. Zelenty

2010-01-14T23:59:59.000Z

456

Nickel based anodes for single chamber solid oxide fuel cells : a catalytic study Geoffroy Gadacz, Sorina Udroiu, Jean-Paul Viricelle, Christophe Pijolat, Michle Pijolat  

E-Print Network [OSTI]

Nickel based anodes for single chamber solid oxide fuel cells : a catalytic study Geoffroy Gadacz Single chamber solid oxide fuel cells (SCFC) are an alternative concept to traditional SOFC-gas-shift equilibrium. Introduction Fifteen years ago, Hibino (1) has shown the feasibility of a fuel cell consisting

Boyer, Edmond

457

Axial magnetic field and toroidally streaming fast ions in the dense plasma focus are natural consequences of conservation laws in the curved axisymmetric geometry of the current sheath  

E-Print Network [OSTI]

Direct measurement of axial magnetic field in the PF-1000 dense plasma focus (DPF), and its reported correlation with neutron emission, call for a fresh look at previous reports of existence of axial magnetic field component in the DPF from other laboratories, and associated data suggesting toroidal directionality of fast ions participating in fusion reactions, with a view to understand the underlying physics. In this context, recent work dealing with application of the hyperbolic conservation law formalism to the DPF is extended in this paper to a curvilinear coordinate system, which reflects the shape of the DPF current sheath. Locally-unidirectional shock propagation in this coordinate system enables construction of a system of 7 one-dimensional hyperbolic conservation law equations with geometric source terms, taking into account all the components of magnetic field and flow velocity. Rankine-Hugoniot jump conditions for this system lead to expressions for the axial magnetic field and three components of ...

Auluck, S K H

2014-01-01T23:59:59.000Z

458

A steerable UV laser system for the calibration of liquid argon time projection chambers  

E-Print Network [OSTI]

A number of liquid argon time projection chambers (LAr TPC's) are being build or are proposed for neutrino experiments on long- and short baseline beams. For these detectors a distortion in the drift field due to geometrical or physics reasons can affect the reconstruction of the events. Depending on the TPC geometry and electric drift field intensity this distortion could be of the same magnitude as the drift field itself. Recently, we presented a method to calibrate the drift field and correct for these possible distortions. While straight cosmic ray muon tracks could be used for calibration, multiple coulomb scattering and momentum uncertainties allow only a limited resolution. A UV laser instead can create straight ionization tracks in liquid argon, and allows one to map the drift field along different paths in the TPC inner volume. Here we present a UV laser feed-through design with a steerable UV mirror immersed in liquid argon that can point the laser beam at many locations through the TPC. The straight ionization paths are sensitive to drift field distortions, a fit of these distortion to the linear optical path allows to extract the drift field, by using these laser tracks along the whole TPC volume one can obtain a 3D drift field map. The UV laser feed-through assembly is a prototype of the system that will be used for the MicroBooNE experiment at the Fermi National Accelerator Laboratory (FNAL).

A. Ereditato; I. Kreslo; M. Lüthi; C. Rudolf von Rohr; M. Schenk; T. Strauss; M. Weber; M. Zeller

2014-10-04T23:59:59.000Z

459

Computer-based on-line pulsed ionization chamber plasma diagnostic system  

SciTech Connect (OSTI)

A pulsed ionization chamber (PIC) plasma diagnostic system described previously for use in the study of ionized gas kinetics for rare gases and their mixtures including He(UF/sub 6/)-a candidate gas core reactor/magnetohydrodynamic (MHD) converter working fluid and a component in wide range radiation field measurement systems has been upgraded in performance to include computer-controlled data acquisition, storage, processing, graphic analysis, and presentation. The current automated system, whose performance is being reported and whose block diagram is shown, is developed around a Macintosh SE microcomputer, IEEE-488 (GPIB) instruments, and a National Instruments interface controller. The results shown not only demonstrate the improved wide-range voltage signal measurement capability of the new PIC system (e.g., from millivolts to tens of volts) but also illustrate the system's capability of easily producing print-ready graphics of experimental data. From automation to report preparation, the new system promises to greatly facilitate the overall process of our experimental plasma diagnostic program and should aid in the implementation in our study of a series of gas core reactor fuel gas/MHD converter working fluids.

Choi, W.Y.; Park, J.S.; Baumgartner, M.J.; Ellis, W.H.

1988-01-01T23:59:59.000Z

460

Pressure Evolution in the Chamber of a Dense Plasma Focus Device  

Science Journals Connector (OSTI)

Adsorption and desorption of impurities in the filling gas by the electrodes the insulator and chamber materials of plasma focus devices have been suggested as probable causes for the fluctuations in their neutron yield. This work describes analysis of data aimed at looking for evidence to support this hypothesis. Before starting each series of discharges a vacuum around 10?6 torr is achieved. The filling gas pure deuterium is maintained under static conditions. A sudden fall of the initial pressure around 5% is systematically observed after the first shot in each series before creeping back at an almost constant rate in successive shots. On the other hand for the first shot with fresh filling gas the neutron yield is always low and systematically increases for the second one. Except for the first two shots we find no evidence to support the hypothesis that the neutron yield fluctuations are related to an adsorption?desorption process. It is also observed that as the number of shots increases for each series the neutron yield variability tends to increase as higher yields are obtained for a few shots.

J. J. E. Herrera; F. Castillo; J. Rangel

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "axial magma chamber" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Laser-assisted homogeneous charge ignition in a constant volume combustion chamber  

Science Journals Connector (OSTI)

Homogeneous charge compression ignition (HCCI) is a very promising future combustion concept for internal combustion engines. There are several technical difficulties associated with this concept, and precisely controlling the start of auto-ignition is the most prominent of them. In this paper, a novel concept to control the start of auto-ignition is presented. The concept is based on the fact that most HCCI engines are operated with high exhaust gas recirculation (EGR) rates in order to slow-down the fast combustion processes. Recirculated exhaust gas contains combustion products including moisture, which has a relative peak of the absorption coefficient around 3 ?m. These water molecules absorb the incident erbium laser radiations (?=2.79 ?m) and get heated up to expedite ignition. In the present experimental work, auto-ignition conditions are locally attained in an experimental constant volume combustion chamber under simulated EGR conditions. Taking advantage of this feature, the time when the mixture is thought to “auto-ignite” could be adjusted/controlled by the laser pulse width optimisation, followed by its resonant absorption by water molecules present in recirculated exhaust gas.

Dhananjay Kumar Srivastava; Martin Weinrotter; Henrich Kofler; Avinash Kumar Agarwal; Ernst Wintner

2009-01-01T23:59:59.000Z

462

Strong Axiality and Ising Exchange Interaction Suppress Zero-Field Tunneling of Magnetization of an Asymmetric Dy2 Single-Molecule Magnet  

Science Journals Connector (OSTI)

Strong Axiality and Ising Exchange Interaction Suppress Zero-Field Tunneling of Magnetization of an Asymmetric Dy2 Single-Molecule Magnet ... The high axiality and Ising exchange interaction efficiently suppress quantum tunneling of magnetization of an asymmetric dinuclear DyIII complex, as revealed by combined experimental and theoretical investigations. ... With the obtained parameters J and zJ, the spectrum of the lowest exchange multiplets is found to be two exchange Ising doublets (Table S4), separated by 2.85 cm–1, each showing a tunneling splitting of the order of 10–8 cm–1 (Figure 4c). ...

Yun-Nan Guo; Gong-Feng Xu; Wolfgang Wernsdorfer; Liviu Ungur; Yang Guo; Jinkui Tang; Hong-Jie Zhang; Liviu F. Chibotaru; Annie K. Powell

2011-07-11T23:59:59.000Z

463

Two-dimensional simulations of thermonuclear burn in ignition-scale inertial confinement fusion targets under compressed axial magnetic fields  

SciTech Connect (OSTI)

We report for the first time on full 2-D radiation-hydrodynamic implosion simulations that explore the impact of highly compressed imposed magnetic fields on the ignition and burn of perturbed spherical implosions of ignition-scale cryogenic capsules. Using perturbations that highly convolute the cold fuel boundary of the hotspot and prevent ignition without applied fields, we impose initial axial seed fields of 20–100 T (potentially attainable using present experimental methods) that compress to greater than 4 × 10{sup 4} T (400 MG) under implosion, thereby relaxing hotspot areal densities and pressures required for ignition and propagating burn by ?50%. The compressed field is high enough to suppress transverse electron heat conduction, and to allow alphas to couple energy into the hotspot even when highly deformed by large low-mode amplitudes. This might permit the recovery of ignition, or at least significant alpha particle heating, in submarginal capsules that would otherwise fail because of adverse hydrodynamic instabilities.

Perkins, L. J.; Logan, B. G.; Zimmerman, G. B.; Werner, C. J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)] [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2013-07-15T23:59:59.000Z

464

Cylindrically confined pair-ion-electron and pair-ion plasmas having axial sheared flow and radial gradients  

SciTech Connect (OSTI)

The linear and nonlinear dynamics of pair-ion (PI) and pair-ion-electron plasmas (PIE) have been investigated in a cylindrical geometry with a sheared plasma flow along the axial direction having radial dependence. The coupled linear dispersion relation of low frequency electrostatic waves has been presented taking into account the Guassian profile of density and linear gradient of sheared flow. It is pointed out that the quasi-neutral cold inhomogeneous pure pair ion plasma supports only the obliquely propagating convective cell mode. The linear dispersion relation of this mode has been solved using boundary conditions. The nonlinear structures in the form of vortices formed by different waves have been discussed in PI and PIE plasmas.

Batool, Nazia; Saleem, H. [National Centre for Physics (NCP), Quaid-i-Azam University Campus, Islamabad (Pakistan)] [National Centre for Physics (NCP), Quaid-i-Azam University Campus, Islamabad (Pakistan)

2013-10-15T23:59:59.000Z

465

Shell model study of $^{40}$Ca muon capture and the $(0^+, 0)$$\\to$$(0^-, 2626)$ axial charge transition  

E-Print Network [OSTI]

We report results from shell model studies of muon capture on $^{40}$Ca to low-lying levels of $^{40}$K. We discuss the comparison between calculated capture rates, measured capture rates and analogous transitions in ($e$,$e^{\\prime}$) scattering in terms of the particle-hole structure of the $^{40}$Ca-$^{40}$K nuclei. We highlight the $^{40}$Ca$(0^+, 0)$$\\to$$^{40}$K$(0^-, 2626)$ axial charge transition and its sensitivity to the induced pseudoscalar coupling $g_p$ of the proton's weak interaction. In addition, we address the hindrance of unique first-forbidden transitions due to particle-hole interactions and the emergence of allowed Gamow-Teller transitions due to ground state correlations. Lastly, we examine the longitudinal alignment of $^{40}$K recoils following muon capture, and discuss this possibility for independently determining the induced coupling $g_p$.

T. P. Gorringe

2006-06-14T23:59:59.000Z

466

A new two-dimensional X-ray drift chamber for diffraction studies with pulsed synchroton radiation  

Science Journals Connector (OSTI)

A two-dimensional position-sensitive detector (drift-chamber) for X-ray difraction experiments with pulsed synchrotron radiation is described. For the measurements of drift direction (x), the small drift chamber uses a reference signal generated by the electron bunches circulating in the storage ring. A flat geometry delay-line, inductively connected to the anode, detects the position of avalanche electrons on the anode wire (y-direction). The main features are: spatial resolution in drift direction (x), 100 ?m for 5 keV photons; spatial resolution in y direction, 400 ?m; maximum counting-rate 5×105 cps; quantum efficiency ar 5 keV, 52%. The systems has been succesfully tested at the ADONE storage ring at Frascati by measuring the small-angle diffraction spectrum of a dry tendon collagen.

Mario Iannuzzi; Andrea La Monaca

1982-01-01T23:59:59.000Z

467

Characterization and use of a 2D-array of ion chambers for brachytherapy dosimetric quality assurance  

SciTech Connect (OSTI)

The two-dimensional (2D) ionization chamber array MatriXX Evolution is one of the 2D ionization chamber arrays developed by IBA Dosimetry (IBA Dosimetry, Germany) for megavoltage real-time absolute 2D dosimetry and verification of intensity-modulated radiation therapy (IMRT). The purpose of this study was to (1) evaluate the performance of ion chamber array for submegavoltage range brachytherapy beam dose verification and quality assurance (QA) and (2) use the end-to-end dosimetric evaluation that mimics a patient treatment procedure and confirm the primary source strength calibration agrees in both the treatment planning system (TPS) and treatment delivery console computers. The dose linearity and energy dependence of the 2D ion chamber array was studied using kilovoltage X-ray beams (100, 180 and 300 kVp). The detector calibration factor was determined using 300 kVp X-ray beams so that we can use the same calibration factor for dosimetric verification of high-dose-rate (HDR) brachytherapy. The phantom used for this measurement consists of multiple catheters, the IBA MatriXX detector, and water-equivalent slab of RW3 to provide full scattering conditions. The treatment planning system (TPS) (Oncentra brachy version 3.3, Nucletron BV, Veenendaal, the Netherlands) dose distribution was calculated on the computed tomography (CT) scan of this phantom. The measured and TPS calculated distributions were compared in IBA Dosimetry OmniPro-I'mRT software. The quality of agreement was quantified by the gamma ({gamma}) index (with 3% delta dose and distance criterion of 2 mm) for 9 sets of plans. Using a dedicated phantom capable of receiving 5 brachytherapy intralumenal catheters a QA procedure was developed for end-to-end dosimetric evaluation for routine QA checks. The 2D ion chamber array dose dependence was found to be linear for 100-300 kVp and the detector response (k{sub user}) showed strong energy dependence for 100-300 kVp energy range. For the Ir-192 brachytherapy HDR source, dosimetric evaluation k{sub user} factor determined by photon beam of energy of 300 kVp was used. The maximum mean difference between ion chamber array measured and TPS calculated was 3.7%. Comparisons of dose distribution for different test plans have shown agreement with >94.5% for {gamma} {<=}1. Dosimetric QA can be performed with the 2D ion chamber array to confirm primary source strength calibration is properly updated in both the TPS and treatment delivery console computers. The MatriXX Evolution ionization chamber array has been found to be reliable for measurement of both absolute dose and relative dose distributions for the Ir-192 brachytherapy HDR source.

Yewondwossen, Mammo, E-mail: mammo.yewondwossen@cdha.nshealth.ca [Department of Radiation Oncology, Dalhousie University, Halifax, Nova Scotia (Canada)

2012-10-01T23:59:59.000Z

468

The UHV Experimental Chamber For Optical Measurements (Reflectivity and Absorption) and Angle Resolved Photoemission of the BEAR Beamline at ELETTRA  

SciTech Connect (OSTI)

The experimental station of the BEAR (Bending magnet for Emission, Absorption and Reflectivity) beamline at ELETTRA (Trieste, Italy) is an UHV chamber conceived to fully exploit the spectroscopic possibilities offered by the light spot produced by the beamline. Spectroscopies include reflectivity ({theta}-2{theta} and diffuse), optical absorption, fluorescence and angle resolved photoemission. The chamber can be rotated around the beam axis to select the s (TE) or p (TM) incidence conditions and/or the position of the ellipse of polarization with respect to the sample. Photon detectors (e.g. photodiodes) and electron detector (hemispherical analyzer - 1 deg. angular resolution, 20 meV energy resolution) cover about completely the full 2{pi} solid angle above the sample surface in any light incidence condition.

Pasquali, L.; Nannarone, S. [UdR-INFM Modena, Universita di Modena and Reggio Emilia, Via Vignolese 905, 41100 Modena (Italy); Dipartimento di Ingegneria dei Materiali e dell'Ambiente, Universita di Modena and Reggio Emilia, Via Vignolese 905, 41100 Modena (Italy); De Luisa, A. [TASC-INFM, MM building in Area Science Park, s.s.14 km 163.5, 34012 Basovizza, Trieste (Italy)

2004-05-12T23:59:59.000Z

469

Homogeneous nucleation rates of higher n -alcohols measured in a laminar flow diffusion chamber  

Science Journals Connector (OSTI)

Nucleation rate isotherms of n-butanol n-pentanol n-hexanol n-heptanol and n-octanol were measured in a laminar flowdiffusion chamber using helium as carrier gas. The measurements were made at 250–310 K corresponding to reduced temperatures of 0.43–0.50 and at atmospheric pressure. Experimental nucleation rate range was from 10 3 to 10 7 ? cm ?3 ? s ?1 . The expression and accuracy of thermodynamic parameters in particular equilibrium vapor pressure were found to have a significant effect on calculated nucleation rates. The results were compared to the classical nucleation theory (CNT) the self-consistency corrected classical theory (SCC) and the Hale’s scaled model of the CNT. The average ratio between the experimental and theoretical nucleation rates for all alcohols used was 1.5×10 3 when the CNT was used and 0.2×10 ?1 when the SCC was used and 0.7×10 ?1 when the Hale’s scaled theory was used. The average values represent all the alcohols used at the same reduced temperatures. The average ratio was about the same throughout the temperature range although J exp /J the calculated with the Hale’s scaled theory increased slightly with increasing temperature. The saturation ratio dependency was predicted closest to experiment with the classical nucleation theory. The nucleation rates were compared to those found in the literature. The measurements were in reasonable agreement with each other. The molecular content of critical alcohol clusters was between 35 and 80 molecules. At a fixed reduced temperature the number of molecules in a critical cluster decreased as a function of alcohol carbon chain length. The number of molecules in critical clusters was compared to those predicted by the Kelvin equation. The theory predicted the critical cluster sizes well.

Antti-Pekka Hyvärinen; Heikki Lihavainen; Yrjö Viisanen; Markku Kulmala

2004-01-01T23:59:59.000Z

470

Scintillation counter and wire chamber front end modules for high energy physics experiments  

SciTech Connect (OSTI)

This document describes two front-end modules developed for the proposed MIPP upgrade (P-960) experiment at Fermilab. The scintillation counter module was developed for the Plastic Ball detector time and charge measurements. The module has eight LEMO 00 input connectors terminated with 50 ohms and accepts negative photomultiplier signals in the range 0.25...1000 pC with the maximum input voltage of 4.0 V. Each input has a passive splitter with integration and differentiation times of {approx}20 ns. The integrated portion of the signal is digitized at 26.55 MHz by Analog Devices AD9229 12-bit pipelined 4-channel ADC. The differentiated signal is discriminated for time measurement and sent to one of the four TMC304 inputs. The 4-channel TMC304 chip allows high precision time measurement of rising and falling edges with {approx}100 ps resolution and has internal digital pipeline. The ADC data is also pipelined which allows deadtime-less operation with trigger decision times of {approx}4 {micro}s. The wire chamber module was developed for MIPP EMCal detector charge measurements. The 32-channel digitizer accepts differential analog signals from four 8-channel integrating wire amplifiers. The connection between wire amplifier and digitizer is provided via 26-wire twist-n-flat cable. The wire amplifier integrates input wire current and has sensitivity of 275 mV/pC and the noise level of {approx}0.013 pC. The digitizer uses the same 12-bit AD9229 ADC chip as the scintillator counter module. The wire amplifier has a built-in test pulser with a mask register to provide testing of the individual channels. Both modules are implemented as a 6Ux220 mm VME size board with 48-pin power connector. A custom europack (VME) 21-slot crate is developed for housing these front-end modules.

Baldin, Boris; DalMonte, Lou; /Fermilab

2011-01-01T23:59:59.000Z

471

Development of a bellows chamber with a comb-type RF shield for high-current accelerators  

Science Journals Connector (OSTI)

An all-metal bellows chamber with a comb-type Radio Frequency (RF) shield for a high-current accelerator was developed and tested at the KEK B-factory (KEKB). The comb-type RF shield has no thin fingers but has nested comb teeth instead at an inner surface. The comb-type RF-shield has a higher thermal strength structurally compared to the conventional finger-type one. Leakage of the TE mode like HOM through the RF shield is almost suppressed. Two test models of bellows chambers installed in the 3.5 GeV positron ring of KEKB showed good properties up to a stored beam current of 1.5 A. The temperature rise of the corrugation was about 7°C and the temperature rise was about 16 of that of the bellows chamber with a conventional finger-type RF shield located under the same condition. The temperature rise of the comb teeth was about 22°C, while that of fingers of the finger-type RF shield was estimated to be about 105°C for the equivalent HOM power. No vacuum arcing was detected during beam operation.

Y. Suetsugu; M. Shirai; K. Shibata; K. Murata; M. Kaneko; K. Sakamoto; K. Sugisaki; M. Kawahara

2004-01-01T23:59:59.000Z

472

David A. Wark | Inventors | GE Global Research  

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

growing inside magma chambers, is widely used today. However, "I'm awaiting invention of cold fusion turbines. Once we have this technology perfected, I suspect mineral dust...

473

Diffraction Phenomena with CO-Axial Plane Piston Transducers A. Goldstein",D. R. Gandhi*, W. D. O'Brien, Jr.'  

E-Print Network [OSTI]

Diffraction Phenomena with CO-Axial Plane Piston Transducers A. Goldstein",D. R. Gandhi*, W. D. O, circular plane piston transducers. The transient and steady-state relations [11for the various maxima of Beissner an The unfocused circular plane piston effective radius can be determined accurately from

Illinois at Urbana-Champaign, University of

474

Magmatic and tectonic extension at mid-ocean ridges: 1. Controls on fault characteristics  

E-Print Network [OSTI]

and the injection of hot magma into the crust. We examine a range of intrusion rates and axial thermal structures@hawaii.edu) [1] We use 2-D numerical models to explore the thermal and mechanical effects of magma intrusion in proportion to the rate of intrusion to simulate the thermal effects of magma crystallization

Ito, Garrett

475

On the structure and properties of a material deposited from arc discharge plasma near the cathode and onto vacuum-chamber walls  

Science Journals Connector (OSTI)

The structure and composition of a material (composite) deposited onto vacuum-chamber walls from arc discharge plasma during the crystallization of cathode spot products in electric and magnetic fields is studied...

N. A. Smolanov; N. A. Pankin

2014-09-01T23:59:59.000Z

476

Relation between the coking-chamber height, the coking pressure, and the packing density of regular or partially briquetted coal batch  

Science Journals Connector (OSTI)

Since coking coal is characterized by both elasticity and ductility in the plastic state, the coal charge of coke furnaces that contains a plastic layer exerts pressure (coking pressure) on the chamber walls. The...

L. V. Kopeliovich; V. I. Sukhorukov; V. I. Shvetsov

2012-07-01T23:59:59.000Z

477

PERFORMANCE CHARACTERISTICS OF THE FERMILAB 15-FOOT BUBBLE CHAMBER WITH A 1/3-SCALE INTERNAL PICKET FENCE (IPF) AND A TWO-PLANE EXTERNAL MUON IDENTIFIER (EMI)  

E-Print Network [OSTI]

L. Stevenson, G. P. Yost; Fermilab: B. Chrisman, D. Gee, A.of Hawaii; and M. Atac, Fermilab; "Status of the InternalPicket Fence for the Fermilab 15-Foot Bubble Chamber", U. H.

Stevenson, M.L.

2011-01-01T23:59:59.000Z

478

SU?C?105?05: Reference Dosimetry of High?Energy Electron Beams with a Farmer?Type Ionization Chamber  

SciTech Connect (OSTI)

Purpose: To investigate gradient effects and provide Monte Carlo calculated beam quality conversion factors to characterize the Farmer?type NE2571 ion chamber for high?energy reference dosimetry of clinical electron beams. Methods: The EGSnrc code system is used to calculate the absorbed dose to water and to the gas in a fully modeled NE2571 chamber as a function of depth in a water phantom. Electron beams incident on the surface of the phantom are modeled using realistic BEAMnrc accelerator simulations and electron beam spectra. Beam quality conversion factors are determined using calculated doses to water and to air in the chamber in high?energy electron beams and in a cobalt?60 reference field. Calculated water?to?air stopping power ratios are employed for investigation of the overall ion chamber perturbation factor. Results: An upstream shift of 0.3–0.4 multiplied by the chamber radius, r-cav, both minimizes the variation of the overall ion chamber perturbation factor with depth and reduces the difference between the beam quality specifier (R{sub 5} {sub 0}) calculated using ion chamber simulations and that obtained with simulations of dose?to?water in the phantom. Beam quality conversion factors are obtained at the reference depth and gradient effects are optimized using a shift of 0.2r-cav. The photon?electron conversion factor, k-ecal, amounts to 0.906 when gradient effects are minimized using the shift established here and 0.903 if no shift of the data is used. Systematic uncertainties in beam quality conversion factors are investigated and amount to between 0.4 to 1.1% depending on assumptions used. Conclusion: The calculations obtained in this work characterize the use of an NE2571 ion chamber for reference dosimetry of high?energy electron beams. These results will be useful as the AAPM continues to review their reference dosimetry protocols.

Muir, B; Rogers, D [Carleton University, Ottawa, ON (Canada)] [Carleton University, Ottawa, ON (Canada)

2013-06-15T23:59:59.000Z

479

Analytical expression for circumferential and axial distribution of absorbed flux on a bent absorber tube of solar parabolic trough concentrator  

Science Journals Connector (OSTI)

Abstract A parabolic trough has a property to concentrate the incident rays at its focal line, when tracked appropriately. The flux distribution on the absorber tube is non-uniform. Part of the absorber’s periphery facing the sun receives direct incident rays where as part of the other side receives concentrated rays resulting in circumferential non-uniform flux distribution. The intensity of flux also varies along the length of the absorber tube, especially at the sun facing end, depending upon the incidence angle of the sun rays and rim angle of the parabolic cylinder. Such non-uniformity in the flux distribution on the absorber tube leads to non-uniform temperature distribution. Thus the absorber experiences thermal stresses which may lead to bending of the tube thereby creating risk of glass cover damage. In order to estimate the extent of bending, study of the flux distribution is needed. In the present work, expression for the absorbed flux on a bent absorber tube accounting circumferential and axial variations is analytically derived. Optical errors and Gaussian sun shape have also been incorporated. Results have been plotted to study the effect of bending, optical errors and rim angle of the trough on flux distribution.

Sourav Khanna; Shireesh B. Kedare; Suneet Singh

2013-01-01T23:59:59.000Z

480

Effect of annealing on SiO{sub x}-TiO{sub 2} axial heterostructure nanowires and improved photodetection  

SciTech Connect (OSTI)

Glancing angle deposition technique has been used to synthesize the axial heterostructure SiO{sub x}-TiO{sub 2} nanowires (NWs) on the Si substrate. The field emission gun scanning electron microscope image shows the formation of perpendicular NWs on Si substrate. A typical transmission electron microscope image confirms the heterostructure NW which consists of SiO{sub x} of length ?130?nm and TiO{sub 2} of length ?170?nm. The amorphous NWs transformed to polycrystalline nature after annealing. The trap assisted radiative recombination process is absent for the annealed NWs. An averagely 1.1 fold enhanced photoabsorption was exhibited by the annealed NWs in the 200–350?nm region and 1.5 fold in the 500–850?nm region. The leakage current (2.6?×?10{sup ?8} A/cm{sup 2} at ?0.5?V) significantly reduced for annealed NWs device. A maximum 1.4?×?10{sup 3} times enlarged photodetection has been observed for annealed device.

Dhar, J. C.; Singh, N. K. [Department of Electronics and Communication Engineering, National Institute of Technology Nagaland, Dimapur, Nagaland 797103 (India); Mondal, A., E-mail: aniruddhamo@gmail.com; Chakrabartty, S. [Department of Electronics and Communication Engineering, National Institute of Technology Agartala, Jirania, Tripura (West) 799055 (India); Bhattacharyya, A. [Department of Radio Physics and Electronics, University of Calcutta, Kolkata 700009 (India); Chattopadhyay, K. K. [Department of Physics, Jadavpur University, Kolkata 700032 (India)

2013-12-28T23:59:59.000Z

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481

Constraints on target chamber first wall and target designs that will enable NIF debris shields to survive  

SciTech Connect (OSTI)

The National Ignition Facility target chamber interior materials and target designs themselves have to be compatible with survival of the final-optics debris shields. To meet the planned maintenance and refinishing rate, the contamination of the debris shields cannot exceed about 1 nm equivalent thickness per shot of total material. This implies that the target mass must be limited to no more than 1 gram and the ablated mass released to the chamber from all other components must not exceed 3 grams. In addition, the targets themselves must either completely vaporize or send any minor amounts of shrapnel towards the chamber waist to prevent excessive cratering of the debris shields. The constraints on the first-wall ablation require that it be louvered to provide passive collection of remobilized contamination, because the expected target debris will remobilize at a rate fast enough to require cleaning every 3 weeks, about three times more frequent than possible with planned robotics. Furthermore, a comparison of ablatants from B{sub 4}C and stainless-steel louvers suggests that remobilization of target debris by x rays will be greater than of the base material in both cases, thereby reducing the performance advantage of clean B{sub 4}C over much-cheaper stainless steel. Neutronics calculations indicate that activation of thin Ni-free stainless steel is not a significant source of maintenance personnel radiation dose. Consequently, the most attractive first wall design consists of stainless-steel louvers. Evaluation of various unconverted-light beam dump designs indicates that stainless steel louvers generate no more debris than other materials, so one single design can serve as both first wall and beam dumps, eliminating beam steering restrictions caused by size and location of the beam dumps. One reservation is that the allowable contamination rate of the debris shield is not yet completely understood.

Hibbard,W.; Burnham, A. K.; Curran, D. R; Genin, F. Y.; Gerassimenko, M.; Latkowski, J. F.; Peterson, P. F.; Scott, J. M.; Tokheim, R. E.; Whitman, P. K.

1998-07-09T23:59:59.000Z

482

Determination of astrophysical thermonuclear rates with a bubble chamber: The {sup 12}C(??){sup 16}O reaction case  

SciTech Connect (OSTI)

The {sup 12}C(??){sup 16}O reaction rate is considered one of the most important unknown parameters in the physics of structure and evolution of massive stars. While extensive experimental campaigns have been performed trying to improve the quality of the measurements, the rate still holds very large uncertainties. Here we discuss a new experimantal scheme to measure the cross section of this reaction with a bubble chamber and a bremsstrahlung beam. The main advantage of the technique is a gain in the luminosity of several orders of magnitude when compared to other ongoing experiments.

DiGiovine, B.; Henderson, D.; Holt, R. J.; Rehm, K. E. [Argonne National Laboratory, Argonne IL 60439 (United States); Grames, J.; Meekins, D.; Poelker, M.; Suleiman, R. [Jefferson Lab, Newport News, VA 23606 (United States); Robinson, A.; Ugalde, C., E-mail: cugalde@uchicago.edu [University of Chicago, Chicago, IL 60637 (United States); Sonnenschein, A. [Fermilab, Batavia, IL 60510 (United States)

2013-11-07T23:59:59.000Z

483

Effects of eddy currents due to a vacuum chamber wall in the airgap of a moving-magnet linear actuator  

SciTech Connect (OSTI)

This paper discusses the effects of eddy currents induced in an electrically conducting plate which is placed in the airgap of a linear synchronous actuator with moving permanent magnets. The eddy currents induced in this plate, which is part of a controlled atmosphere chamber, cause not only damping but also deteriorate the actuator performance by disturbing the position measurement with Hall sensors. Furthermore, feed-forward controllers are less effective due to the suppression of high frequent armature fields. These effects are analyzed with an analytical model and verified with finite element simulations and measurements.

Jansen, J. W.; Lomonova, E. A.; Rovers, J. M. M. [Department of Electrical Engineering, Eindhoven University of Technology, Den Dolech 2, 5612 AZ Eindhoven (Netherlands)

2009-04-01T23:59:59.000Z

484

Precise 3D track reconstruction algorithm for the ICARUS T600 liquid argon time projection chamber detector  

E-Print Network [OSTI]

Liquid Argon Time Projection Chamber (LAr TPC) detectors offer charged particle imaging capability with remarkable spatial resolution. Precise event reconstruction procedures are critical in order to fully exploit the potential of this technology. In this paper we present a new, general approach of three-dimensional reconstruction for the LAr TPC with a practical application to track reconstruction. The efficiency of the method is evaluated on a sample of simulated tracks. We present also the application of the method to the analysis of real data tracks collected during the ICARUS T600 detector operation with the CNGS neutrino beam.

M. Antonello; B. Baibussinov; P. Benetti; E. Calligarich; N. Canci; S. Centro; A. Cesana; K. Cieslik; D. B. Cline; A. G. Cocco; A. Dabrowska; D. Dequal; A. Dermenev; R. Dolfini; C. Farnese; A. Fava; A. Ferrari; G. Fiorillo; D. Gibin; S. Gninenko; A. Guglielmi; M. Haranczyk; J. Holeczek; A. Ivashkin; J. Kisiel; I. Kochanek; J. Lagoda; S. Mania; A. Menegolli; G. Meng; C. Montanari; S. Otwinowski; A. Piazzoli; P. Picchi; F. Pietropaolo; P. Plonski; A. Rappoldi; G. L. Raselli; M. Rossella; C. Rubbia; P. Sala; A. Scaramelli; E. Segreto; F. Sergiampietri; D. Stefan; J. Stepaniak; R. Sulej; M. Szarska; M. Terrani; F. Varanini; S. Ventura; C. Vignoli; H. Wang; X. Yang; A. Zalewska; K. Zaremba

2012-10-18T23:59:59.000Z

485

Measurement of absorbed dose-to-water for an HDR {sup 192}Ir source with ionization chambers in a sandwich setup  

SciTech Connect (OSTI)

Purpose: In this study, a dedicated device for ion chamber measurements of absorbed dose-to-water for a Nucletron microSelectron-v2 HDR {sup 192}Ir brachytherapy source is presented. The device uses two ionization chambers in a so-called sandwich assembly. Using this setup and by taking the average reading of the two chambers, any dose error due to difficulties in absolute positioning (centering) of the source in between the chambers is cancelled to first order. The method's accuracy was examined by comparing measurements with absorbed dose-to-water determination based on the AAPM TG-43 protocol.Methods: The optimal source-to-chamber distance (SCD) for {sup 192}Ir dosimetry was determined from ion chamber measurements in a water phantom. The {sup 192}Ir source was sandwiched between two Exradin A1SL chambers (0.057 cm{sup 3}) at the optimal SCD separation. The measured ionization was converted to the absorbed dose-to-water using a {sup 60}Co calibration factor and a Monte Carlo-calculated beam quality conversion factor, k{sub Q}, for {sup 60}Co to {sup 192}Ir. An uncertainty estimate of the proposed method was determined based on reproducibility of measurements at different institutions for the same type of source.Results: The optimal distance for the A1SL chamber measurements was determined to be 5 cm from the {sup 192}Ir source center, considering the depth dependency of k{sub Q} for {sup 60}Co to {sup 192}Ir and the chamber positioning. The absorbed dose to water measured at (5 cm, 90°) on the transverse axis was 1.3% lower than TG-43 values and its reproducibility and overall uncertainty were 0.8% and 1.7%, respectively. The measurement doses at anisotropic points agreed within 1.5% with TG-43 values.Conclusions: The ion chamber measurement of absorbed dose-to-water with a sandwich method for the {sup 192}Ir source provides a more accurate, direct, and reference dose compared to the dose-to-water determination based on air-kerma strength in the TG-43 protocol. Due to the simple but accurate assembly, the sandwich measurement method is useful for daily dose management of {sup 192}Ir sources.

Araki, Fujio; Kouno, Tomohiro; Ohno, Takeshi [Department of Health Sciences, Faculty of Life Sciences, Kumamoto University, 4-24-1 Kuhonji, Kumamoto 862-0976 (Japan)] [Department of Health Sciences, Faculty of Life Sciences, Kumamoto University, 4-24-1 Kuhonji, Kumamoto 862-0976 (Japan); Kakei, Kiyotaka; Yoshiyama, Fumiaki [Department of Radiotherapy, Kumamoto University Hospital, 1-1-1 Honjyo, Kumamoto 860-8556 (Japan)] [Department of Radiotherapy, Kumamoto University Hospital, 1-1-1 Honjyo, Kumamoto 860-8556 (Japan); Kawamura, Shinji [Department of Radiotherapy, Miyazaki University Hospital, 5200 Kihara Ohaza Kiyotake-Machi, Miyazaki 889-1692 (Japan)] [Department of Radiotherapy, Miyazaki University Hospital, 5200 Kihara Ohaza Kiyotake-Machi, Miyazaki 889-1692 (Japan)

2013-09-15T23:59:59.000Z

486

Improved blue response and efficiency of A-Si:H solar cells deposited from disilane using a dual-chamber plasma system  

SciTech Connect (OSTI)

Thin film amorphous silicon solar cells with glass/SnO/sub 2//p/i/n/Al structures and 6 to 7% AM1 conversion efficiencies were fabricated at rapid deposition rates in a newly constructed dual-chamber glow discharge deposition system. The 500 nm thick intrinsic layer was deposited at the rate of 1.7 nm/s using disilane (Si/sub 2/H/sub 6/)-helium mixtures. This deposition rate is an order of magnitude greater than conventional high efficiency amorphous silicon solar cell depositions. Residual boron doping effects at the p/i interface can severely degrade cell performance particularly when the intrinsic layer is deposited in one chamber of the dual-chamber system and the intrinsic layer is deposited in the other chamber that is free of boron contaminants. Parameters such as electrode spacing, Si/sub 2/H/sub 6/ partial pressure and flow rate were optimized to produce uniform deposition over large areas. At the substrate temperature T/sub s/ selected for solar cell intrinsic layer deposition, the spin density was measured to be a minimum at 5 x 10/sup 15//cm/sup 3/. For a given T/sub s/, an intrinsic layer deposited from Si/sub 2/H/sub 6/ absorbs fewer photons and can generate less current under solar simulation than a similar film produced from monosilane. Identical solar cells were deposited in either the single-chamber mode or the dual-chamber mode for comparison. Single-chamber mode cells perform poorly over the visible wavelengths and hence produce low short circuit currents. The dual-chamber mode cells show a significant improvement in blue response and a factor of two increase in short circuit current over the single-chamber mode cells. Under short circuit conditions, 15 mA/cm/sup 2/ was generated from rapidly deposited (1.7 nm/s) cells from disilane and 18 mA/cm/sup 2/ from low deposition rate (0.18 nm/s) monosilane cells. These values are comparable to or better than those reported for similar cells by other groups.

Rajeswaran, G.; Vanier, P.E.; Corderman, R.R.; Kampas, F.J.

1985-01-01T23:59:59.000Z

487

Air kerma standard for calibration of well-type chambers in Brazil using {sup 192}Ir HDR sources and its traceability  

SciTech Connect (OSTI)

In Brazil there are over 100 high dose rate (HDR) brachytherapy facilities using well-type chambers for the determination of the air kerma rate of {sup 192}Ir sources. This paper presents the methodology developed and extensively tested by the Laboratorio de Ciencias Radiologicas (LCR) and presently in use to calibrate those types of chambers. The system was initially used to calibrate six well-type chambers of brachytherapy services, and the maximum deviation of only 1.0% was observed between the calibration coefficients obtained and the ones in the calibration certificate provided by the UWADCL. In addition to its traceability to the Brazilian National Standards, the whole system was taken to University of Wisconsin Accredited Dosimetry Calibration Laboratory (UWADCL) for a direct comparison and the same formalism to calculate the air kerma was used. The comparison results between the two laboratories show an agreement of 0.9% for the calibration coefficients. Three Brazilian well-type chambers were calibrated at the UWADCL, and by LCR, in Brazil, using the developed system and a clinical HDR machine. The results of the calibration of three well chambers have shown an agreement better than 1.0%. Uncertainty analyses involving the measurements made both at the UWADCL and LCR laboratories are discussed.

Di Prinzio, Renato; Almeida, Carlos Eduardo de [Laboratorio de Ciencias Radiologicas-Universidade do Estado do Rio de Janeiro (LCR/UERJ), R. Sao Francisco Xavier, 524, Pavilhao Haroldo Lisboa da Cunha, Terreo, Sala 136-Maracana, CEP 20550-900-Rio de Janeiro/RJ-Rio de Janeiro, RJ (Brazil) and Instituto de Radioprotecao e Dosimetria-Comissao Nacional de Energia Nuclear (IRD/CNEN), Av. Salvador Allende, s/n, Jacarepagua-CE22780-160-Rio de Janeiro, RJ (Brazil); Laboratorio de Ciencias Radiologicas-Universidade do Estado do Rio de Janeiro (LCR/UERJ), R. Sao Francisco Xavier, 524, Pavilhao Haroldo Lisboa da Cunha, Terreo, Sala 136-Maracana, CEP 20550-900-Rio de Janeiro/RJ-Rio de Janeiro, RJ (Brazil)

2009-03-15T23:59:59.000Z

488

Dynamic Positional Change and Defocus Curve of a Phakic Foldable Anterior-Chamber Angle-Supported Intraocular Lens during Accommodation  

Science Journals Connector (OSTI)

Objective To evaluate movements of an anterior-chamber angle-supported phakic intraocular lens (PIOL) Cachet (Alcon, Fort Worth, Texas) and their influence on visual acuity during accommodation. Design Prospective case series. Participants We included 54 eyes of 27 patients (15 female, 12 male; age, 38±7.61 years; preoperative manifest spherical equivalent ?8.7±2.5 diopters [D]). Methods Evaluation of the PIOL's positional stability (distance to the corneal endothelium [M1] and the natural lens [M2]) as well as the pre- and postoperative anterior chamber depth (ACD) and pupil diameter (PD). Measurements were performed for accommodation stimuli ranging from ?7 to +1 D in 1-D increments using optical coherence tomography (Visante OCT, Carl Zeiss Meditec, Jena, Germany). The respective defocus curve was evaluated using Early Treatment Diabetic Retinopathy Study charts. Statistical analysis included a Kolmogoroff-Smirnov test for parametric distribution, a Friedman- and consecutive Conover-Iman-Bonferroni test for detection of PD, ACD, and defocus curve differences from before to after the operation, a 1-sided t test for analysis of positional changes (?PD, ?ACD, and ?M values compared with a zero stimulus position), and a regression analysis for the evaluation of influence of age, IOL diameter, and power on ?-values. Significance was set at P = 0.05. Main Outcome Measures Postoperative ?M values. Results The PD, ?PD, ACD, and ?ACD did not differ significantly between pre- and postoperative values. The ?M1 and ?M2 differed significantly from the zero-stimulus position for defocus stimuli of ??3 D and ??2D, respectively; mean ?M1max was ?0.09±0.06 mm for ?7-D stimulus; mean ?M2max was ?0.09±0.10 mm for ?5-/?6-D stimulus. Apart from ?PD, all ?-values decreased with age. Visual acuity was significantly better postoperatively for defocus stimuli between 0 and ?3 D. Conclusions The anterior-chamber angle-supported PIOL changes its position during accommodation only marginally. The PIOL does not affect postoperative accommodation. Financial Disclosure(s) Proprietary or commercial disclosure may be found after the references.

Oliver K. Klaproth; Jörg Rehrmann; Thomas Kohnen

2013-01-01T23:59:59.000Z

489

S T A T E OF CONNECTICUT E X E C U T I V E CHAMBERS M  

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

T T A T E OF CONNECTICUT E X E C U T I V E CHAMBERS M . JODI R E L L GOVERNOR The Honorable Steven Chu, Secretary United States Department of Energy 1000 Independence Avenue, S. W. Washington, D.C. 20585 March 23,2009 Dear Secretary Chu: Re: State Energy Program Assurances In accordance with Section 41 0 of the American Recovery and Reinvestment Act of 2009,I hereby notify you that I have obtained necessary assurances that each of the following will occur: (1) The applicable State regulatory authority will seek to implement, in appropriate proceedings for each electric and gas utility, with respect to which the State regulatory authority has ratemaking authority, a general policy that ensures that utility financial incentives are aligned with helping their customers use energy more efficiently and that provide timely cost recovery

490

Experimental analysis of general ion recombination in a liquid-filled ionization chamber in high-energy photon beams  

SciTech Connect (OSTI)

Purpose: To study experimentally the general ion recombination effect in a liquid-filled ionization chamber (LIC) in high-energy photon beams. Methods: The general ion recombination effect on the response of a micro liquid ion chamber (microLion) was investigated with a 6 MV photon beam in normal and SRS modes produced from a Varian{sup Registered-Sign} Novalis Tx{sup TM} linear accelerator. Dose rates of the linear accelerator were set to 100, 400, and 1000 MU/min, which correspond to pulse repetition frequencies of 60, 240, and 600 Hz, respectively. Polarization voltages applied to the microLion were +800 and +400 V. The relative collection efficiency of the microLion response as a function of dose per pulse was experimentally measured with changing polarization voltage and pulse repetition frequencies and was compared with the theoretically calculated value. Results: For the 60 Hz pulse repetition frequency, the experimental relative collection efficiency was not different from the theoretical one for a pulsed beam more than 0.3% for both polarization voltages. For a pulsed radiation beam with a higher pulse repetition frequency, the experimental relative collection efficiency converged to the theoretically calculated efficiency for continuous beams. This result indicates that the response of the microLion tends toward the response to a continuous beam with increasing pulse repetition frequency of a pulsed beam because of low ion mobility in the liquid. Conclusions: This work suggests an empirical method to correct for differences in general ion recombination of a LIC between different radiation fields. More work is needed to quantitatively explain the LIC general ion recombination behavior in pulsed beams generated from linear accelerators.

Chung, Eunah; Seuntjens, Jan [Medical Physics Unit, McGill University, Montreal General Hospital (L5-113), 1650 Cedar Avenue, Montreal, Quebec H3G 1A4 (Canada); Davis, Stephen [Department of Medical Physics, McGill University Health Centre, Montreal General Hospital (L5-112), 1650 Cedar Avenue, Montreal, Quebec H3G 1A4 (Canada)

2013-06-15T23:59:59.000Z

491

Design of an ultrahigh vacuum transfer mechanism to interconnect an oxide molecular beam epitaxy growth chamber and an x-ray photoemission spectroscopy analysis system  

SciTech Connect (OSTI)

We designed a mechanism and the accompanying sample holders to transfer between a VEECO 930 oxide molecular beam epitaxy (MBE) and a PHI Versa Probe X-ray photoemission spectroscopy (XPS) chamber within a multiple station growth, processing, and analysis system through ultrahigh vacuum (UHV). The mechanism consists of four parts: (1) a platen compatible with the MBE growth stage, (2) a platen compatible with the XPS analysis stage, (3) a sample coupon that is transferred between the two platens, and (4) the accompanying UHV transfer line. The mechanism offers a robust design that enables transfer back and forth between the growth chamber and the analysis chamber, and yet is flexible enough to allow transfer between standard sample holders for thin film growth and masked sample holders for making electrical contacts and Schottky junctions, all without breaking vacuum. We used this mechanism to transfer a barium strontium titanate thin film into the XPS analysis chamber and performed XPS measurements before and after exposing the sample to the air. After air exposure, a thin overlayer of carbon was found to form and a significant shift ({approx}1 eV) in the core level binding energies was observe