National Library of Energy BETA

Sample records for bubble chamber tracks

  1. ON THE ANALYSIS OF BUBBLE CHAMBER TRACKS Bradner, H.; Solmitz...

    Office of Scientific and Technical Information (OSTI)

    ON THE ANALYSIS OF BUBBLE CHAMBER TRACKS Bradner, H.; Solmitz, F. 08 HYDROGEN; 43 PARTICLE ACCELERATORS; BEVATRON; BUBBLE CHAMBERS; DETECTION; HYDROCARBONS; HYDROGEN; INVENTIONS;...

  2. Neutron Detection via Bubble Chambers

    SciTech Connect (OSTI)

    Jordan, David V.; Ely, James H.; Peurrung, Anthony J.; Bond, Leonard J.; Collar, J. I.; Flake, Matthew; Knopf, Michael A.; Pitts, W. K.; Shaver, Mark W.; Sonnenschein, Andrew; Smart, John E.; Todd, Lindsay C.

    2005-10-06

    The results of a Pacific Northwest National Laboratory (PNNL) exploratory research project investigating the feasibility of fast neutron detection using a suitably prepared and operated, pressure-cycled bubble chamber are described. The research was conducted along two parallel paths. Experiments with a slow pressure-release Halon chamber at the Enrico Fermi Institute at the University of Chicago showed clear bubble nucleation sensitivity to an AmBe neutron source and insensitivity to the 662 keV gammas from a 137Cs source. Bubble formation was documented via high-speed (1000 frames/sec) photography, and the acoustic signature of bubble formation was detected using a piezo-electric transducer element mounted on the base of the chamber. The chamber’s neutron sensitivity as a function of working fluid temperature was mapped out. The second research path consisted of the design, fabrication, and testing of a fast pressure-release Freon-134a chamber at PNNL. The project concluded with successful demonstrations of the PNNL chamber’s AmBe neutron source sensitivity and 137Cs gamma insensitivity. The source response tests of the PNNL chamber were documented with high-speed photography.

  3. History of the superconducting-magnet bubble chambers

    SciTech Connect (OSTI)

    Derrick, M.; Hyman, L.G.; Pewitt, E.G.

    1980-01-01

    This review covers the development of superconducting magnets, small bubble chambers, and the early history of the 12-foot bubble chamber. (MOW)

  4. Donald Glaser, the Bubble Chamber, and Elementary Particles

    Office of Scientific and Technical Information (OSTI)

    Biotech Pioneer Donald Glaser ... Donald A. Glaser, Ph.D.; The Bubble Chamber, ... Neurobiology (an interview) -- accepting agreement results in receiving the document Invention...

  5. Luis Alvarez, the Hydrogen Bubble Chamber, Tritium, and Dinosaurs

    Office of Scientific and Technical Information (OSTI)

    Luis Alvarez, the Hydrogen Bubble Chamber, Tritium, and Dinosaurs Resources with ... standard of length, co-discovered the hydrogen isotope tritium, searched for hidden ...

  6. Direct Measurement of the Bubble Nucleation Energy Threshold in a CF3I Bubble Chamber

    SciTech Connect (OSTI)

    Behnke, E.; Benjamin, T.; Brice, S. J.; Broemmelsiek, D.; Collar, J. I.; Cooper, P. S.; Crisler, M.; Dahl, C. E.; Fustin, D.; Hall, Jeter C.; Harnish, C.; Levine, I.; Lippincott, W. H.; Moan, T.; Nania, T.; Neilson, R.; Ramberg, E.; Robinson, A. E.; Ruschman, M.; Sonnenschein, Andrew; Vazquez-Jauregui, E.; RIvera, R. A.; Uplegger, L.

    2013-07-30

    Here, we measured the energy threshold and efficiency for bubble nucleation from iodine recoils in a CF3I bubble chamber in the energy range of interest for a dark matter search. These interactions cannot be probed by standard neutron calibration methods, so we develop a new technique by observing the elastic scattering of 12 GeV/c negative pions. The pions are tracked with a silicon pixel telescope and the reconstructed scattering angle provides a measure of the nuclear recoil kinetic energy. The bubble chamber was operated with a nominal threshold of (13.6±0.6) keV. Interpretation of the results depends on the response to fluorine and carbon recoils, but in general we find agreement with the predictions of the classical bubble-nucleation theory. Moreover, this measurement confirms the applicability of CF3I as a target for spin-independent dark matter interactions and represents a novel technique for calibration of superheated fluid detectors.

  7. Dark matter limits froma 15 kg windowless bubble chamber

    SciTech Connect (OSTI)

    Szydagis, Matthew Mark; /Chicago U.

    2010-12-01

    The COUPP collaboration has successfully used bubble chambers, a technology previously applied only to high-energy physics experiments, as direct dark matter detectors. It has produced the world's most stringent spin-dependent WIMP limits, and increasingly competitive spin-independent limits. These limits were achieved by capitalizing on an intrinsic rejection of the gamma background that all other direct detection experiments must address through high-density shielding and empirically-determined data cuts. The history of COUPP, including its earliest prototypes and latest results, is briefly discussed in this thesis. The feasibility of a new, windowless bubble chamber concept simpler and more inexpensive in design is discussed here as well. The dark matter limits achieved with a 15 kg windowless chamber, larger than any previous COUPP chamber (2 kg, 4 kg), are presented. Evidence of the greater radiopurity of synthetic quartz compared to natural is presented using the data from this 15 kg device, the first chamber to be made from synthetic quartz. The effective reconstruction of the three-dimensional positions of bubbles in a highly distorted optical field, with ninety-degree bottom lighting similar to cloud chamber lighting, is demonstrated. Another innovation described in this thesis is the use of the sound produced by bubbles recorded by an array of piezoelectric sensors as the primary means of bubble detection. In other COUPP chambers, cameras have been used as the primary trigger. Previous work on bubble acoustic signature differentiation using piezos is built upon in order to further demonstrate the ability to discriminate between alpha- and neutron-induced events.

  8. Dark Matter Search Results from the PICO-60 CF$_3$I Bubble Chamber...

    Office of Scientific and Technical Information (OSTI)

    Dark Matter Search Results from the PICO-60 CF3I Bubble Chamber Citation Details In-Document Search Title: Dark Matter Search Results from the PICO-60 CF3I Bubble Chamber...

  9. On the Analysis of Bubble Chamber Tracks

    DOE R&D Accomplishments [OSTI]

    Bradner, H; Solmitz, F.

    1958-06-01

    No abstract provided. Prepared for the Second U.N. International Conference on the Peaceful Uses of Atomic Energy, 1958

  10. Luis Alvarez, the Hydrogen Bubble Chamber, Tritium, and Dinosaurs

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

    Luis Alvarez, the Hydrogen Bubble Chamber, Tritium, and Dinosaurs Resources with Additional Information * Patents Luis Alvarez Courtesy Lawrence Berkeley National Laboratory 'Luis W. Alvarez was an adventurer physicist. The two terms may seem an odd combination until one considers Alvarez's career. A member of the National Inventor's Hall of Fame, Alvarez developed the proton linear accelerator, patented three types of radar still used today, designed an instrument that for 15 years served as

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

    ScienceCinema (OSTI)

    Glaser, Don

    2011-04-28

    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.

  12. Dark Matter Search Results from the PICO-60 CF$_3$I Bubble Chamber

    SciTech Connect (OSTI)

    Amole, C.

    2015-10-26

    We reported new data from the operation of the PICO-60 dark matter detector, a bubble chamber filled with 36.8 kg of CF3I and located in the SNOLAB underground laboratory. PICO-60 is the largest bubble chamber to search for dark matter to date. With an analyzed exposure of 92.8 live-days, PICO-60 exhibits the same excellent background rejection observed in smaller bubble chambers. Alpha decays in PICO-60 exhibit frequency-dependent acoustic calorimetry, similar but not identical to that reported recently in a C3F8 bubble chamber. PICO-60 also observes a large population of unknown background events, exhibiting acoustic, spatial, and timing behaviors inconsistent with those expected from a dark matter signal. We found these behaviors allow for analysis cuts to remove all background events while retaining 48.2%of the exposure. Stringent limits on WIMPs interacting via spin-dependent proton and spin-independent processes are set, and the interpretation of the DAMA/LIBRA modulation signal as dark matter interacting with iodine nuclei is ruled out.

  13. COUPP - a search for dark matter with a continuously sensitive bubble chamber

    SciTech Connect (OSTI)

    Collar, Juan,; Crum, Keith; Mishra, Smriti; Nakazawa, Dante; Odom, Brian; Rasmussen, Julia; Riley, Nathan; Szydagis, Matthew; Behnke, Ed; Levine, Ilan; Vander Werf, Nate; Cooper, Peter; Crisler, Mike; Hu, Martin; Ramberg, Erik; Sonnenschein, Andrew; Tschirhart, Robert; /Fermilab

    2007-01-01

    We propose to construct and operate a 60-kg room temperature CF{sub 3}I bubble chamber as a prototype dark matter (WIMP) detector. Operating in weakly-superheated mode, the chamber will be sensitive to WIMP induced nuclear recoils above 10 keV, while rejecting background electron recoils at a level approaching 10{sup 10}. We would first commission and operate this chamber in the MINOS near detector hall with the goal to demonstrate stable operation and measure internal contamination and any other backgrounds. This chamber, or an improved version, would then be relocated to an appropriate deep underground site such as the Soudan Mine. This detector will have unique sensitivity to spin-dependent WIMP-nucleon couplings, and even in this early stage of development will attain competitive sensitivity to spin-independent couplings.

  14. Dark Matter Limits From a 2L C3F8 Filled Bubble Chamber

    SciTech Connect (OSTI)

    Robinson, Alan Edward

    2015-12-01

    The PICO-2L C3F8 bubble chamber search forWeakly Interacting Massive Particle (WIMP) dark matter was operated in the SNOLAB underground laboratory at the same location as the previous CF3I lled COUPP-4kg detector. Neutron calibrations using photoneutron sources in C3F8 and CF3I lled calibration bubble chambers were performed to verify the sensitivity of these target uids to dark matter scattering. This data was combined with similar measurements using a low-energy neutron beam at the University of Montreal and in situ calibrations of the PICO-2L and COUPP-4kg detectors. C3F8 provides much greater sensitivity to WIMP-proton scattering than CF3I in bubble chamber detectors. PICO-2L searched for dark matter recoils with energy thresholds below 10 keV. Radiopurity assays of detector materials were performed and the expected neutron recoil background was evaluated to be 1.6+0:3

  15. Readout of TPC Tracking Chambers with GEMs and Pixel Chip

    SciTech Connect (OSTI)

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

    2007-12-21

    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.

  16. PICASSO, COUPP and PICO - Search for dark matter with bubble chambers

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

    Amole, C.; Ardid, M.; Asner, D. M.; Baxter, D.; Behnke, E.; Bhattacharjee, P.; Borsodi, H.; Bou-Cabo, M.; Brice, S. J.; Broemmelsiek, D.; et al

    2015-05-29

    The PICASSO and COUPP collaborations use superheated liquid detectors to search for cold dark matter through the direct detection of weakly interacting massive particles (WIMPs). These experiments, located in the underground laboratory of SNOLAB, Canada, detect phase transitions triggered by nuclear recoils in the keV range induced by interactions with WIMPs. We present details of the construction and operation of these detectors as well as the results, obtained by several years of observations. We also introduce PICO, a joint effort of the two collaborations to build a second generation ton-scale bubble chamber with 250 liters of active liquid.

  17. Dark Matter Search Results from the PICO-2L C3F8 Bubble Chamber

    SciTech Connect (OSTI)

    Amole, C.; Ardid, M.; Asner, David M.; Baxter, D.; Behnke, E.; Bhattacharjee, P. S.; Borsodi, H.; Bou-Cabo, M.; Brice, S. J.; Broemmelsiek, D.; Clark, K.; Collar, J. I.; Cooper, P. S.; Crisler, M.; Dahl, C. E.; Daley, S.; Das, Madhusmita; Debris, F.; Dhungana, N.; Farine, J.; Felis, I.; Filgas, R.; Fines-Neuschild, M.; Girard, Francoise; Giroux, G.; Hai, M.; Hall, Jeter C.; Harris, O.; Jackson, C. M.; Jin, M.; Krauss, C. B.; Lafreniere, M.; Laurin, M.; Lawson, I.; Levine, I.; Lippincott, W. H.; Mann, E.; Martin, J. P.; Maurya, D.; Mitra, Pitam; Neilson, R.; Noble, A. J.; Plante, A.; Podviianiuk, R. B.; Priya, S.; Robinson, A. E.; Ruschman, M.; Scallon, O.; Seth, S.; Sonnenschein, Andrew; Starinski, N.; Stekl, I.; Vazquez-Jauregui, E.; Wells, J.; Wichoski, U.; Zacek, V.; Zhang, J.

    2015-06-12

    New data are reported from the operation of a 2-liter C3F8 bubble chamber in the 2100 meter deep SNOLAB underground laboratory, with a total exposure of 211.5 kg-days at four different recoil energy thresholds ranging from 3.2 keV to 8.1 keV. These data show that C3F8 provides excellent electron recoil and alpha rejection capabilities at very low thresholds, including the rst observation of a dependence of acoustic signal on alpha energy. Twelve single nuclear recoil event candidates were observed during the run. The candidate events exhibit timing characteristics that are not consistent with the hypothesis of a uniform time distribution, and no evidence for a dark matter signal is claimed. These data provide the most sensitive direct detection constraints on WIMP-proton spin-dependent scattering to date, with signicant sensitivity at low WIMP masses for spin-independent WIMP-nucleon scattering.

  18. Dark matter search results from the PICO-2L C$_3$F$_8$ bubble chamber

    SciTech Connect (OSTI)

    Amole, C.

    2015-06-11

    New data are reported from the operation of a 2 liter C3F8 bubble chamber in the SNOLAB underground laboratory, with a total exposure of 211.5 kg days at four different energy thresholds below 10 keV. These data show that C3F8 provides excellent electron-recoil and alpha rejection capabilities at very low thresholds. The chamber exhibits an electron-recoil sensitivity of < 3.5 1010 and an alpha rejection factor of > 98.2%. These data also include the first observation of a dependence of acoustic signal on alpha energy. Twelve single nuclear recoil event candidates were observed during the run. The candidate events exhibit timing characteristics that are not consistent with the hypothesis of a uniform time distribution, and no evidence for a dark matter signal is claimed. Lastly, these data provide the most sensitive direct detection constraints on WIMP-proton spin-dependent scattering to date, with significant sensitivity at low WIMP masses for spin-independent WIMP-nucleon scattering.

  19. Dark matter search results from the PICO-2L C$_3$F$_8$ bubble chamber

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

    Amole, C.

    2015-06-11

    New data are reported from the operation of a 2 liter C3F8 bubble chamber in the SNOLAB underground laboratory, with a total exposure of 211.5 kg days at four different energy thresholds below 10 keV. These data show that C3F8 provides excellent electron-recoil and alpha rejection capabilities at very low thresholds. The chamber exhibits an electron-recoil sensitivity of < 3.5 × 10–10 and an alpha rejection factor of > 98.2%. These data also include the first observation of a dependence of acoustic signal on alpha energy. Twelve single nuclear recoil event candidates were observed during the run. The candidate eventsmore » exhibit timing characteristics that are not consistent with the hypothesis of a uniform time distribution, and no evidence for a dark matter signal is claimed. Lastly, these data provide the most sensitive direct detection constraints on WIMP-proton spin-dependent scattering to date, with significant sensitivity at low WIMP masses for spin-independent WIMP-nucleon scattering.« less

  20. Dark matter search results from the PICO-2L C$_3$F$_8$ bubble chamber

    SciTech Connect (OSTI)

    Amole, C.

    2015-06-11

    New data are reported from the operation of a 2 liter C3F8 bubble chamber in the SNOLAB underground laboratory, with a total exposure of 211.5 kg days at four different energy thresholds below 10 keV. These data show that C3F8 provides excellent electron-recoil and alpha rejection capabilities at very low thresholds. The chamber exhibits an electron-recoil sensitivity of < 3.5 × 10–10 and an alpha rejection factor of > 98.2%. These data also include the first observation of a dependence of acoustic signal on alpha energy. Twelve single nuclear recoil event candidates were observed during the run. The candidate events exhibit timing characteristics that are not consistent with the hypothesis of a uniform time distribution, and no evidence for a dark matter signal is claimed. Lastly, these data provide the most sensitive direct detection constraints on WIMP-proton spin-dependent scattering to date, with significant sensitivity at low WIMP masses for spin-independent WIMP-nucleon scattering.

  1. A Proposal for a Ton Scale Bubble Chamber for Dark Matter Detection

    SciTech Connect (OSTI)

    Collar, Juan; Dahl, C.Eric; Fustin, Drew; Robinson, Alan; Behnke, Ed; Behnke, Joshua; Breznau, William; Connor, Austin; Kuehnemund, Emily Grace; Levine, Ilan; Moan, Timothy; /Indiana U., South Bend /Fermilab

    2010-10-07

    The nature of non-baryonic dark matter is one of the most intriguing questions for particle physics at the start of the 21st century. There is ample evidence for its existence, but almost nothing is known of its properties. WIMPs are a very appealing candidate particle and several experimental campaigns are underway around the world to search for these particles via the nuclear recoils that they should induce. The COUPP series of bubble chambers has played a significant role in the WIMP search. Through a sequence of detectors of increasing size, a number of R&D issues have arisen and been solved, and the technology has now been advanced to the point where the construction of large chambers requires a modest research effort, some development, but mostly just engineering. It is within this context that we propose to build the next COUPP detector - COUPP-500, a ton scale device to be built over the next three years at Fermilab and then deployed deep underground at SNOLAB. The primary advantages of the COUPP approach over other technologies are: (1) The ability to reject electron and gamma backgrounds by arranging the chamber thermodynamics such that these particles do not even trigger the detector. (2) The ability to suppress neutron backgrounds by having the radioactively impure detection elements far from the active volume and by using the self-shielding of a large device and the high granularity to identify multiple bubbles. (3) The ability to build large chambers cheaply and with a choice of target fluids. (4) The ability to increase the size of the chambers without changing the size or complexity of the data acquisition. (5) Sensitivity to spin-dependent and spin-independent WIMP couplings. These key advantages should enable the goal of one background event in a ton-year of exposure to be achieved. The conceptual design of COUPP-500 is scaled from the preceding devices. In many cases all that is needed is a simple scaling up of components previously used

  2. Improved Limits on Spin-Dependent WIMP-Proton Interactions from a Two Liter CF$_3$I Bubble Chamber

    SciTech Connect (OSTI)

    Behnke, E.; Behnke, J.; Brice, S.J.; Broemmelsiek, D.; Collar, J.I.; Cooper, P.S.; Crisler, M.; Dahl, C.E.; Fustin, D.; Hall, J.; Hinnefeld, J.H.; /Indiana U., South Bend /Fermilab /Indiana U., South Bend /Fermilab /Indiana U., South Bend /Fermilab

    2010-08-01

    Data from the operation of a bubble chamber filled with 3.5 kg of CF{sub 3}I in a shallow underground site are reported. An analysis of ultrasound signals accompanying bubble nucleations confirms that alpha decays generate a significantly louder acoustic emission than single nuclear recoils, leading to an efficient background discrimination. Three dark matter candidate events were observed during an effective exposure of 28.1 kg-day, consistent with a neutron background. This observation provides the strongest direct detection constraint to date on WIMP-proton spin-dependent scattering for WIMP masses > 20 GeV/c{sup 2}.

  3. A sun-tracking environmental chamber for the outdoor quantification of CPV modules

    SciTech Connect (OSTI)

    Faiman, David Melnichak, Vladimir Bokobza, Dov Kabalo, Shlomo

    2014-09-26

    The paper describes a sun-tracking environmental chamber and its associated fast electronics, devised for the accurate outdoor characterization of CPV cells, receivers, mono-modules, and modules. Some typical measurement results are presented.

  4. First Dark Matter Search Results from a 4-kg CF$_3$I Bubble Chamber Operated in a Deep Underground Site

    SciTech Connect (OSTI)

    Behnke, E.; Behnke, J.; Brice, S.J.; Broemmelsiek, D.; Collar, J.I.; Conner, A.; Cooper, P.S.; Crisler, M.; Dahl, C.E.; Fustin, D.; Grace, E.; /Indiana U., South Bend /Fermilab

    2012-04-01

    New data are reported from the operation of a 4.0 kg CF{sub 3}I bubble chamber in the 6800 foot deep SNOLAB underground laboratory. The effectiveness of ultrasound analysis in discriminating alpha decay background events from single nuclear recoils has been confirmed, with a lower bound of >99.3% rejection of alpha decay events. Twenty single nuclear recoil event candidates and three multiple bubble events were observed during a total exposure of 553 kg-days distributed over three different bubble nucleation thresholds. The effective exposure for single bubble recoil-like events was 437.4 kg-days. A neutron background internal to the apparatus, of known origin, is estimated to account for five single nuclear recoil events and is consistent with the observed rate of multiple bubble events. This observation provides world best direct detection constraints on WIMP-proton spin-dependent scattering for WIMP masses >20 GeV/c{sup 2} and demonstrates significant sensitivity for spin-independent interactions.

  5. Improved Limits on Spin-Dependent WIMP-Proton Interactions from a Two Liter CF{sub 3}I Bubble Chamber

    SciTech Connect (OSTI)

    Behnke, E.; Behnke, J.; Hinnefeld, J. H.; Levine, I.; Shepherd, T.; Brice, S. J.; Broemmelsiek, D.; Cooper, P. S.; Crisler, M.; Hall, J.; Hu, M.; Ramberg, E.; Sonnenschein, A.; Collar, J. I.; Dahl, C. E.; Fustin, D.; Szydagis, M.

    2011-01-14

    Data from the operation of a bubble chamber filled with 3.5 kg of CF{sub 3}I in a shallow underground site are reported. An analysis of ultrasound signals accompanying bubble nucleations confirms that alpha decays generate a significantly louder acoustic emission than single nuclear recoils, leading to an efficient background discrimination. Three dark matter candidate events were observed during an effective exposure of 28.1 kg day, consistent with a neutron background. This observation provides strong direct detection constraints on weakly interacting massive particle (WIMP)-proton spin-dependent scattering for WIMP masses >20 GeV/c{sup 2}.

  6. Flow chamber

    DOE Patents [OSTI]

    Morozov, Victor

    2011-01-18

    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.

  7. Bubble diagnostics

    DOE Patents [OSTI]

    Visuri, Steven R.; Mammini, Beth M.; Da Silva, Luiz B.; Celliers, Peter M.

    2003-01-01

    The present invention is intended as a means of diagnosing the presence of a gas bubble and incorporating the information into a feedback system for opto-acoustic thrombolysis. In opto-acoustic thrombolysis, pulsed laser radiation at ultrasonic frequencies is delivered intraluminally down an optical fiber and directed toward a thrombus or otherwise occluded vessel. Dissolution of the occlusion is therefore mediated through ultrasonic action of propagating pressure or shock waves. A vapor bubble in the fluid surrounding the occlusion may form as a result of laser irradiation. This vapor bubble may be used to directly disrupt the occlusion or as a means of producing a pressure wave. It is desirable to detect the formation and follow the lifetime of the vapor bubble. Knowledge of the bubble formation and lifetime yields critical information as to the maximum size of the bubble, density of the absorbed radiation, and properties of the absorbing material. This information can then be used in a feedback system to alter the irradiation conditions.

  8. Development of Microstrip Gas Chambers for Radiation Detection...

    Office of Scientific and Technical Information (OSTI)

    Gas Chambers for Radiation Detection and Tracking at High Rates: Final Status Repor Citation Details In-Document Search Title: Development of Microstrip Gas Chambers for ...

  9. Target Chamber

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

    Who Partners with NIF? FAQs Visit Us home about how nif works beamline target chamber Target Chamber The "Grand Central Station" of the National Ignition Facility is the ...

  10. Exposure chamber

    DOE Patents [OSTI]

    Moss, Owen R.; Briant, James K.

    1983-01-01

    An exposure chamber includes an imperforate casing having a fluid inlet at the top and an outlet at the bottom. A single vertical series of imperforate trays is provided. Each tray is spaced on all sides from the chamber walls. Baffles adjacent some of the trays restrict and direct the flow to give partial flow back and forth across the chambers and downward flow past the lowermost pan adjacent a central plane of the chamber.

  11. Exposure chamber

    DOE Patents [OSTI]

    Moss, Owen R.

    1980-01-01

    A chamber for exposing animals, plants, or materials to air containing gases or aerosols is so constructed that catch pans for animal excrement, for example, serve to aid the uniform distribution of air throughout the chamber instead of constituting obstacles as has been the case in prior animal exposure chambers. The chamber comprises the usual imperforate top, bottom and side walls. Within the chamber, cages and their associated pans are arranged in two columns. The pans are spaced horizontally from the walls of the chamber in all directions. Corresponding pans of the two columns are also spaced horizontally from each other. Preferably the pans of one column are also spaced vertically from corresponding pans of the other column. Air is introduced into the top of the chamber and withdrawn from the bottom. The general flow of air is therefore vertical. The effect of the horizontal pans is based on the fact that a gas flowing past the edge of a flat plate that is perpendicular to the flow forms a wave on the upstream side of the plate. Air flows downwardly between the chamber walls and the outer edges of the pan. It also flows downwardly between the inner edges of the pans of the two columns. It has been found that when the air carries aerosol particles, these particles are substantially uniformly distributed throughout the chamber.

  12. Wire chamber

    DOE Patents [OSTI]

    Atac, Muzaffer

    1989-01-01

    A wire chamber or proportional counter device, such as Geiger-Mueller tube or drift chamber, improved with a gas mixture providing 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.

  13. IONIZATION CHAMBER

    DOE Patents [OSTI]

    Redman, W.C.; Shonka, F.R.

    1958-02-18

    This patent describes a novel ionization chamber which is well suited to measuring the radioactivity of the various portions of a wire as the wire is moved at a uniform speed, in order to produce the neutron flux traverse pattern of a reactor in which the wire was previously exposed to neutron radiation. The ionization chamber of the present invention is characterized by the construction wherein the wire is passed through a tubular, straight electrode and radiation shielding material is disposed along the wire except at an intermediate, narrow area where the second electrode of the chamber is located.

  14. Ionization chamber

    DOE Patents [OSTI]

    Walenta, Albert H.

    1981-01-01

    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.

  15. Ionization chamber

    DOE Patents [OSTI]

    Walenta, A.H.

    An ionization chamber is described which 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 ionizes the gas.

  16. Sharp Interface Tracking in Rotating Microflows of Solvent Extraction...

    Office of Scientific and Technical Information (OSTI)

    interface tracking simulation capability for predicting ... and the surrounding shearing fluid for realistic flows. ... model drop and bubble interactions in a domain ...

  17. Prospects for bubble fusion

    SciTech Connect (OSTI)

    Nigmatulin, R.I.; Lahey, R.T. Jr.

    1995-09-01

    In this paper a new method for the realization of fusion energy is presented. This method is based on the superhigh compression of a gas bubble (deuterium or deuterium/thritium) in heavy water or another liquid. The superhigh compression of a gas bubble in a liquid is achieved through forced non-linear, non-periodic resonance oscillations using moderate amplitudes of forcing pressure. The key feature of this new method is a coordination of the forced liquid pressure change with the change of bubble volume. The corresponding regime of the bubble oscillation has been called {open_quotes}basketball dribbling (BD) regime{close_quotes}. The analytical solution describing this process for spherically symmetric bubble oscillations, neglecting dissipation and compressibility of the liquid, has been obtained. This solution shown no limitation on the supercompression of the bubble and the corresponding maximum temperature. The various dissipation mechanisms, including viscous, conductive and radiation heat losses have been considered. It is shown that in spite of these losses it is possible to achieve very high gas bubble temperatures. This because the time duration of the gas bubble supercompression becomes very short when increasing the intensity of compression, thus limiting the energy losses. Significantly, the calculated maximum gas temperatures have shown that nuclear fusion may be possible. First estimations of the affect of liquid compressibility have been made to determine possible limitations on gas bubble compression. The next step will be to investigate the role of interfacial instability and breaking down of the bubble, shock wave phenomena around and in the bubble and mutual diffusion of the gas and the liquid.

  18. The Mark III vertex chamber

    SciTech Connect (OSTI)

    Adler, J.; Bolton, T.; Bunnell, K.; Cassell, R.; Cheu, E.; Freese, T.; Grab, C.; Mazaheri, G.; Mir, R.; Odian, A.

    1987-07-01

    The design and construction of the new Mark III vertex chamber is described. Initial tests with cosmic rays prove the ability of track reconstruction and yield triplet resolutions below 50 ..mu..m at 3 atm using argon/ethane (50:50). Also performed are studies using a prototype of a pressurized wire vertex chamber with 8 mm diameter straw geometry. Spatial resolution of 35mm was obtained using dimethyl ether (DME) at 1 atm and 30 ..mu..m using argon/ethane (50/50 mixture) at 4 atm. Preliminary studies indicate the DME to adversely affect such materials as aluminized Mylar and Delrin.

  19. Chamber transport

    SciTech Connect (OSTI)

    OLSON,CRAIG L.

    2000-05-17

    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.

  20. Rotating bubble membrane radiator

    DOE Patents [OSTI]

    Webb, Brent J.; Coomes, Edmund P.

    1988-12-06

    A heat radiator useful for expelling waste heat from a power generating system aboard a space vehicle is disclosed. Liquid to be cooled is passed to the interior of a rotating bubble membrane radiator, where it is sprayed into the interior of the bubble. Liquid impacting upon the interior surface of the bubble is cooled and the heat radiated from the outer surface of the membrane. Cooled liquid is collected by the action of centrifical force about the equator of the rotating membrane and returned to the power system. Details regarding a complete space power system employing the radiator are given.

  1. Single wire drift chamber design

    SciTech Connect (OSTI)

    Krider, J.

    1987-03-30

    This report summarizes the design and prototype tests of single wire drift chambers to be used in Fermilab test beam lines. The goal is to build simple, reliable detectors which require a minimum of electronics. Spatial resolution should match the 300 ..mu..m rms resolution of the 1 mm proportional chambers that they will replace. The detectors will be used in beams with particle rates up to 20 KHz. Single track efficiency should be at least 99%. The first application will be in the MT beamline, which has been designed for calibration of CDF detectors. A set of four x-y modules will be used to track and measure the momentum of beam particles.

  2. Donald Glaser, the Bubble Chamber, and Elementary Particles

    Office of Scientific and Technical Information (OSTI)

    Courtesy of and The University of California, Berkeley The 1960 Nobel Prize in ... Glaser joined the University of California faculty in 1959. Five years later, he ...

  3. Donald Glaser, the Bubble Chamber, and Elementary Particles

    Office of Scientific and Technical Information (OSTI)

    Now a Professor of the Graduate School, Glaser's research has shifted to the construction of computational models that shed light on the physics and physiology of human ...

  4. TITLE AUTHORS SUBJECT SUBJECT RELATED DESCRIPTION PUBLISHER AVAILABILI...

    Office of Scientific and Technical Information (OSTI)

    ON THE ANALYSIS OF BUBBLE CHAMBER TRACKS Bradner H Solmitz F HYDROGEN PARTICLE ACCELERATORS BEVATRON BUBBLE CHAMBERS DETECTION HYDROCARBONS HYDROGEN INVENTIONS PHYSICS PROTONS...

  5. Gas bubble disease: introduction

    SciTech Connect (OSTI)

    Fickeisen, D.H.; Schneider, M.J.; Wedemeyer, G.A.

    1980-11-01

    In 1970, gas bubble disease was identified as a serious problem affecting salmonids in the Columbia and Snake river systems. The source of supersaturation was entrainment of air into water spilling over hydroelectric dams. Regional research projects focusing on tolerance bioassays were immediately implemented. Since then, the scope of gas bubble disease research has broadened to include problems in other aquatic systems, with other species. Emphasis has shifted from defining tolerance limits in bioassay systems to exploring behavioral and physiological aspects. Various methods of degasifying supersaturated water have been developed.

  6. Two chamber reaction furnace

    DOE Patents [OSTI]

    Blaugher, R.D.

    1998-05-05

    A vertical two chamber reaction furnace is described. The furnace comprises a lower chamber having an independently operable first heating means for heating the lower chamber and a gas inlet means for admitting a gas to create an ambient atmosphere, and an upper chamber disposed above the lower chamber and having an independently operable second heating means for heating the upper chamber. Disposed between the lower chamber and the upper chamber is a vapor permeable diffusion partition. The upper chamber has a conveyor means for conveying a reactant there through. Of particular importance is the thallinating of long-length thallium-barium-calcium-copper oxide (TBCCO) or barium-calcium-copper oxide (BCCO) precursor tapes or wires conveyed through the upper chamber to thereby effectuate the deposition of vaporized thallium (being so vaporized as the first reactant in the lower chamber at a temperature between about 700 C and 800 C) on TBCCO or BCCO tape or wire (the second reactant) at its simultaneous annealing temperature in the upper chamber of about 800 to 950 C to thereby replace thallium oxide lost from TBCCO tape or wire because of the high annealing temperature or to deposit thallium on BCCO tape or wire. Continuously moving the tape or wire provides a single-step process that effectuates production of long-length TBCCO superconducting product. 2 figs.

  7. Two chamber reaction furnace

    DOE Patents [OSTI]

    Blaugher, Richard D.

    1998-05-05

    A vertical two chamber reaction furnace. The furnace comprises a lower chamber having an independently operable first heating means for heating the lower chamber and a gas inlet means for admitting a gas to create an ambient atmosphere, and an upper chamber disposed above the lower chamber and having an independently operable second heating means for heating the upper chamber. Disposed between the lower chamber and the upper chamber is a vapor permeable diffusion partition. The upper chamber has a conveyor means for conveying a reactant there through. Of particular importance is the thallinating of long-length thallium-barium-calcium-copper oxide (TBCCO) or barium-calcium-copper oxide (BCCO) precursor tapes or wires conveyed through the upper chamber to thereby effectuate the deposition of vaporized thallium (being so vaporized as the first reactant in the lower chamber at a temperature between about 700.degree. and 800.degree. C.) on TBCCO or BCCO tape or wire (the second reactant) at its simultaneous annealing temperature in the upper chamber of about 800.degree. to 950.degree. C. to thereby replace thallium oxide lost from TBCCO tape or wire because of the high annealing temperature or to deposit thallium on BCCO tape or wire. Continuously moving the tape or wire provides a single-step process that effectuates production of long-length TBCCO superconducting product.

  8. Kathy Chambers | Department of Energy

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

    Kathy Chambers About Us Kathy Chambers - Senior Science and Technical Information Specialist, OSTI Most Recent by Kathy Chambers A Shining Example of Dr. King's legacy January 9

  9. Electron Bubbles in Liquid Helium

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

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

  10. Math of Popping Bubbles in a Foam

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

    Math of Popping Bubbles in a Foam Math of Popping Bubbles in a Foam Berkeley Lab researchers mathematically describe the complex evolution and disappearance of foamy bubbles May 9, ...

  11. Bubble masks for time-encoded imaging of fast neutrons.

    SciTech Connect (OSTI)

    Brubaker, Erik; Brennan, James S.; Marleau, Peter; Nowack, Aaron B.; Steele, John; Sweany, Melinda; Throckmorton, Daniel J.

    2013-09-01

    Time-encoded imaging is an approach to directional radiation detection that is being developed at SNL with a focus on fast neutron directional detection. In this technique, a time modulation of a detected neutron signal is induced-typically, a moving mask that attenuates neutrons with a time structure that depends on the source position. An important challenge in time-encoded imaging is to develop high-resolution two-dimensional imaging capabilities; building a mechanically moving high-resolution mask presents challenges both theoretical and technical. We have investigated an alternative to mechanical masks that replaces the solid mask with a liquid such as mineral oil. Instead of fixed blocks of solid material that move in pre-defined patterns, the oil is contained in tubing structures, and carefully introduced air gaps-bubbles-propagate through the tubing, generating moving patterns of oil mask elements and air apertures. Compared to current moving-mask techniques, the bubble mask is simple, since mechanical motion is replaced by gravity-driven bubble propagation; it is flexible, since arbitrary bubble patterns can be generated by a software-controlled valve actuator; and it is potentially high performance, since the tubing and bubble size can be tuned for high-resolution imaging requirements. We have built and tested various single-tube mask elements, and will present results on bubble introduction and propagation as a function of tubing size and cross-sectional shape; real-time bubble position tracking; neutron source imaging tests; and reconstruction techniques demonstrated on simple test data as well as a simulated full detector system.

  12. Observations of solute effects on bubble formation

    SciTech Connect (OSTI)

    Hofmeier, U.; Yaminsky, V.V.; Christenson, H.K.

    1995-09-01

    The authors have studied the effects of solute, in particular aqueous electrolyte, on bubble formation at capillary orifices and frits at varying gas flow rates. Using a stroboscope, video microscope, and rotating mirror, they have obtained pictures which show how bubble formation involves the interaction of bubbles at the orifice. These interactions depend on the value of the surface elasticity E due to positively (ethanol) or negatively (NaCl) adsorbed solute. At low flow rates consecutive bubbles do not interact. Each bubble detaches and leaves the orifice region before the next one starts forming. A intermediate flow rates the more closely spaced, consecutive bubbles begin to interact. In pure liquids there is no barrier to bubble coalescence and the detached bubble is fed by the subsequent bubble as this starts to grow. The process may be repeated several times before the original bubble has risen out of range. In solutions where E is large enough bubble coalescence is inhibited. Instead of feeding into the detached bubble the following bubble pushes it aside, and the bubbles appear to bounce off each other. Bouncing may give rise to a characteristic sequence of larger and smaller bubbles if the emerging bubbles break off prematurely from the orifice due to the inertia of the original bubble. The transition from feeding to bouncing depends critically on E of the solution and leads to a smaller average bubble size for large E values. At high flow rates detached bubbles are invariably fed by several subsequent ones. At very high flow rates the bubbling becomes chaotic, but the interaction of bubbles after leaving the orifice area produces smaller bubbles in solutions. Bouncing is more likely to occur with narrow and irregular capillaries. The dramatically different appearance of gas-sparged columns in salt water and freshwater has its origin in the difference between assemblies of pores showing mainly feeding (freshwater) or bouncing (salt water).

  13. Bubble column apparatus for separating wax from catalyst slurry

    DOE Patents [OSTI]

    Neathery, James K.; Davis, Burtron H.

    2004-07-13

    Novel methods and devices for production of liquid hydrocarbon products from gaseous reactants are disclosed. In one aspect, a method for separating a liquid hydrocarbon, typically a wax, from a catalyst containing slurry is provided, comprising passing the slurry through at least one downcomer extending from an overhead separation chamber and discharging into the bottom of a slurry bubble column reactor. The downcomer includes a cross-flow filtration element for separating a substantially particle-free liquid hydrocarbon for downstream processing. In another aspect, a method for promoting plug-flow movement in a recirculating slurry bubble column reactor is provided, comprising discharging the recirculating slurry into the reactor through at least one downcomer which terminates near the bottom of the reactor. Devices for accomplishing the above methods are also provided.

  14. Sleeve reaction chamber system

    SciTech Connect (OSTI)

    Northrup, M. Allen; Beeman, Barton V.; Benett, William J.; Hadley, Dean R.; Landre, Phoebe; Lehew, Stacy L.; Krulevitch, Peter A.

    2009-08-25

    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.

  15. Photothermally controlled Marangoni flow around a micro bubble...

    Office of Scientific and Technical Information (OSTI)

    We have experimentally investigated the control of Marangoni flow around a micro bubble ... bubble and to control the temperature gradient around the bubble at a micrometer scale. ...

  16. TRACKING SITE

    Energy Science and Technology Software Center (OSTI)

    003235MLTPL00 AASG Geothermal Data submissions tracking application and site. https://github.com/usgin/aasgtrack

  17. Automated soil gas monitoring chamber

    DOE Patents [OSTI]

    Edwards, Nelson T.; Riggs, Jeffery S.

    2003-07-29

    A chamber for trapping soil gases as they evolve from the soil without disturbance to the soil and to the natural microclimate within the chamber has been invented. The chamber opens between measurements and therefore does not alter the metabolic processes that influence soil gas efflux rates. A multiple chamber system provides for repetitive multi-point sampling, undisturbed metabolic soil processes between sampling, and an essentially airtight sampling chamber operating at ambient pressure.

  18. Novel techniques for slurry bubble column hydrodynamics

    SciTech Connect (OSTI)

    Dudukovic, M.P.

    1999-05-14

    The objective of this cooperative research effort between Washington University, Ohio State University and Exxon Research Engineering Company was to improve the knowledge base for scale-up and operation of slurry bubble column reactors for syngas conversion and other coal conversion processes by increased reliance on experimentally verified hydrodynamic models. During the first year (July 1, 1995--June 30, 1996) of this three year program novel experimental tools (computer aided radioactive particle tracking (CARPT), particle image velocimetry (PIV), heat probe, optical fiber probe and gamma ray tomography) were developed and tuned for measurement of pertinent hydrodynamic quantities, such as velocity field, holdup distribution, heat transfer and bubble size. The accomplishments were delineated in the First Technical Annual Report. The second year (July, 1996--June 30, 1997) was spent on further development and tuning of the novel experimental tools (e.g., development of Monte Carlo calibration for CARPT, optical probe development), building up the hydrodynamic data base using these tools and comparison of the two techniques (PIV and CARPT) for determination of liquid velocities. A phenomenological model for gas and liquid backmixing was also developed. All accomplishments were summarized in the Second Annual Technical Report. During the third and final year of the program (July 1, 1997--June 30, 1998) and during the nine months no cost extension, the high pressure facility was completed and a set of data was taken at high pressure conditions. Both PIV, CT and CARPT were used. More fundamental hydrodynamic modeling was also undertaken and model predictions were compared to data. The accomplishments for this period are summarized in this report.

  19. Improved wire chamber

    DOE Patents [OSTI]

    Atac, M.

    1987-05-12

    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.

  20. Multi-chamber deposition system

    DOE Patents [OSTI]

    Jacobson, Richard L.; Jeffrey, Frank R.; Westerberg, Roger K.

    1989-06-27

    A system for the simultaneous deposition of different coatings onto a thin web within a large volume vacuum chamber is disclosed which chamber is provided with a plurality of deposition chambers in which the different layers are deposited onto the film as its moves from a supply roll to a finished take-up roll of coated web. The deposition chambers provided within the large vacuum chamber are provided with separate seals which minimize back diffusion of any dopant gas from adjacent deposition chambers.

  1. Multi-chamber deposition system

    DOE Patents [OSTI]

    Jacobson, Richard L.; Jeffrey, Frank R.; Westerberg, Roger K.

    1989-10-17

    A system for the simultaneous deposition of different coatings onto a thin web within a large volume vacuum chamber is disclosed which chamber is provided with a plurality of deposition chambers in which the different layers are deposited onto the film as its moves from a supply roll to a finished take-up roll of coated web. The deposition chambers provided within the large vacuum chamber are provided with separate seals which minimize back diffusion of any dopant gas from adjacent deposition chambers.

  2. Polymer insulator profiles evaluated in a fog chamber

    SciTech Connect (OSTI)

    Gorur, R.S. . Dept. of Electrical and Computer Engineering); Cherney, E.A. ); Hackam, R. )

    1990-04-01

    This paper presents the results of fog chamber experiments done to examine the tracking and erosion performance of polymer insulator profiles. The effect of weathershed material, construction, orientation, and ac and dc voltage are examined. Correlation between cylindrical rod specimens of materials and insulator profiles is shown. The protected leakage path provided by the weathershed is found to play a major role in the tracking and erosion performance of polymer insulators. The resistance to tracking and erosion of insulator profiles with dc is shown to be reduced in comparison to ac. Cylindrical rods of material yielded the same ranking of material performance as insulator profiles but in a shorter time.

  3. Three chamber negative ion source

    DOE Patents [OSTI]

    Leung, Ka-Ngo; Ehlers, Kenneth W.; Hiskes, John R.

    1985-01-01

    A negative ion vessel is divided into an excitation chamber, a negative ionization chamber and an extraction chamber by two magnetic filters. Input means introduces neutral molecules into a first chamber where a first electron discharge means vibrationally excites the molecules which migrate to a second chamber. In the second chamber a second electron discharge means ionizes the molecules, producing negative ions which are extracted into or by a third chamber. A first magnetic filter prevents high energy electrons from entering the negative ionization chamber from the excitation chamber. A second magnetic filter prevents high energy electrons from entering the extraction chamber from the negative ionizing chamber. An extraction grid at the end of the negative ion vessel attracts negative ions into the third chamber and accelerates them. Another grid, located adjacent to the extraction grid, carries a small positive voltage in order to inhibit positive ions from migrating into the extraction chamber and contour the plasma potential. Additional electrons can be suppressed from the output flux using ExB forces provided by magnetic field means and the extractor grid electric potential.

  4. Vertical two chamber reaction furnace

    DOE Patents [OSTI]

    Blaugher, R.D.

    1999-03-16

    A vertical two chamber reaction furnace is disclosed. The furnace comprises a lower chamber having an independently operable first heating means for heating the lower chamber and a gas inlet means for admitting a gas to create an ambient atmosphere, and an upper chamber disposed above the lower chamber and having an independently operable second heating means for heating the upper chamber. Disposed between the lower chamber and the upper chamber is a vapor permeable diffusion partition. The upper chamber has a conveyor means for conveying a reactant there through. Of particular importance is the thallinating of long-length thallium-barium-calcium copper oxide (TBCCO) or barium-calcium-copper oxide (BCCO) precursor tapes or wires conveyed through the upper chamber to thereby effectuate the deposition of vaporized thallium (being so vaporized as the first reactant in the lower chamber at a temperature between about 700 and 800 C) on TBCCO or BCCO tape or wire (the second reactant) at its simultaneous annealing temperature in the upper chamber of about 800 to 950 C to thereby replace thallium oxide lost from TBCCO tape or wire because of the high annealing temperature or to deposit thallium on BCCO tape or wire. Continuously moving the tape or wire provides a single-step process that effectuates production of long-length TBCCO superconducting product. 2 figs.

  5. Vertical two chamber reaction furnace

    DOE Patents [OSTI]

    Blaugher, Richard D.

    1999-03-16

    A vertical two chamber reaction furnace. The furnace comprises a lower chamber having an independently operable first heating means for heating the lower chamber and a gas inlet means for admitting a gas to create an ambient atmosphere, and an upper chamber disposed above the lower chamber and having an independently operable second heating means for heating the upper chamber. Disposed between the lower chamber and the upper chamber is a vapor permeable diffusion partition. The upper chamber has a conveyor means for conveying a reactant there through. Of particular importance is the thallinating of long-length thallium-barium-calcium-copper oxide (TBCCO) or barium-calcium-copper oxide (BCCO) precursor tapes or wires conveyed through the upper chamber to thereby effectuate the deposition of vaporized thallium (being so vaporized as the first reactant in the lower chamber at a temperature between about 700.degree. and 800.degree. C.) on TBCCO or BCCO tape or wire (the second reactant) at its simultaneous annealing temperature in the upper chamber of about 800.degree. to 950.degree. C. to thereby replace thallium oxide lost from TBCCO tape or wire because of the high annealing temperature or to deposit thallium on BCCO tape or wire. Continuously moving the tape or wire provides a single-step process that effectuates production of long-length TBCCO superconducting product.

  6. Etiology of gas bubble disease

    SciTech Connect (OSTI)

    Bouck, G.R.

    1980-11-01

    Gas bubble disease is a noninfectious, physically induced process caused by uncompensated hyperbaric pressure of total dissolved gases. When pressure compensation is inadequate, dissolved gases may form emboli (in blood) and emphysema (in tissues). The resulting abnormal physical presence of gases can block blood vessels (hemostasis) or tear tissues, and may result in death. Population mortality is generally skewed, in that the median time to death occurs well before the average time to death. Judged from mortality curves, three stages occur in gas bubble disease: (1) a period of gas pressure equilibrium, nonlethal cavitation, and increasing morbidity; (2) a period of rapid and heavy mortality; and (3) a period of protracted survival, despite lesions, and dysfunction that eventually terminates in total mortality. Safe limits for gas supersaturation depend on species tolerance and on factors that differ among hatcheries and rivers, between continuous and intermittent exposures, and across ranges of temperature and salinity.

  7. Multi-anode ionization chamber

    DOE Patents [OSTI]

    Bolotnikov, Aleksey E.; Smith, Graham; Mahler, George J.; Vanier, Peter E.

    2010-12-28

    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.

  8. Ionization chamber dosimeter

    DOE Patents [OSTI]

    Renner, Tim R.; Nyman, Mark A.; Stradtner, Ronald

    1991-01-01

    A method for fabricating an ion chamber dosimeter collecting array of the type utilizing plural discrete elements formed on a uniform collecting surface which includes forming a thin insulating layer over an aperture in a frame having surfaces, forming a predetermined pattern of through holes in the layer, plating both surfaces of the layer and simultaneously tilting and rotating the frame for uniform plate-through of the holes between surfaces. Aligned masking and patterned etching of the surfaces provides interconnects between the through holes and copper leads provided to external circuitry.

  9. Chamber for the optical manipulation of microscopic particles

    DOE Patents [OSTI]

    Buican, Tudor N.; Upham, Bryan D.

    1992-01-01

    A particle control chamber enables experiments to be carried out on biological cells and the like using a laser system to trap and manipulate the particles. A manipulation chamber provides a plurality of inlet and outlet ports for the particles and for fluids used to control or to contact the particles. A central manipulation area is optically accessible by the laser and includes first enlarged volumes for containing a selected number of particles for experimentation. A number of first enlarged volumes are connected by flow channels through second enlarged volumes. The second enlarged volumes act as bubble valves for controlling the interconnections between the first enlarged volumes. Electrode surfaces may be applied above the first enlarged volumes to enable experimentation using the application of electric fields within the first enlarged volumes. A variety of chemical and environmental conditions may be established within individual first enlarged volumes to enable experimental conditions for small scale cellular interactions.

  10. Mechanism of bubble detachment from vibrating walls

    SciTech Connect (OSTI)

    Kim, Dongjun; Park, Jun Kwon Kang, Kwan Hyoung; Kang, In Seok

    2013-11-15

    We discovered a previously unobserved mechanism by which air bubbles detach from vibrating walls in glasses containing water. Chaotic oscillation and subsequent water jets appeared when a wall vibrated at greater than a critical level. Wave forms were developed at water-air interface of the bubble by the wall vibration, and water jets were formed when sufficiently grown wave-curvatures were collapsing. Droplets were pinched off from the tip of jets and fell to the surface of the glass. When the solid-air interface at the bubble-wall attachment point was completely covered with water, the bubble detached from the wall. The water jets were mainly generated by subharmonic waves and were generated most vigorously when the wall vibrated at the volume resonant frequency of the bubble. Bubbles of specific size can be removed by adjusting the frequency of the wall's vibration.

  11. CASL - Lift Forces in Bubbly Flows

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

    Lift Forces in Bubbly Flows The dynamics of two-phase (gas/liquid) bubbly flows are complex: bubbles deform and disperse; large latent heats and heat capacity differentials influence local boiling; and relatively small changes in heated surface temperatures yield order of magnitude changes in boiling complexity. Because the local void volume has a direct feedback effect on reactor neutron flux and fuel rod power production, prediction of local boiling rates and bulk boiling effects in nuclear

  12. Math of Popping Bubbles in a Foam

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

    Math of Popping Bubbles in a Foam Math of Popping Bubbles in a Foam Berkeley Lab researchers mathematically describe the complex evolution and disappearance of foamy bubbles May 9, 2013 Media Contacts: UC Berkeley: Robert Sanders, rsanders@berkeley.edu, (510) 643-6998 Berkeley Lab: Linda Vu, lvu@lbl.gov, (510) 495-2404 Written By Robert Sanders Bubble baths and soapy dishwater, the refreshing head on a beer and the luscious froth on a cappuccino. All are foams, beautiful yet ephemeral as the

  13. Effect of Bubbles and Silica Dissolution on Melter Feed Rheology...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Effect of Bubbles and Silica Dissolution on Melter Feed Rheology during Conversion to Glass Citation Details In-Document Search Title: Effect of Bubbles and Silica ...

  14. Bubble Radiation Detection: Current and Future Capability (Technical...

    Office of Scientific and Technical Information (OSTI)

    Bubble Radiation Detection: Current and Future Capability Citation Details In-Document Search Title: Bubble Radiation Detection: Current and Future Capability Despite a number of ...

  15. Ion chamber based neutron detectors

    DOE Patents [OSTI]

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

    2014-12-16

    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.

  16. A high rate proportional chamber

    SciTech Connect (OSTI)

    Henderson, R.; Fraszer, W.; Openshaw, R.; Sheffer, G.; Salomon, M.; Dew, S.; Marans, J.; Wilson, P.

    1987-02-01

    Gas mixtures with high specific ionization allow the use of small interelectrode distances while still maintaining full efficiency. With the short electron drift distances the timing resolution is also improved. The authors have built and operated two 25 cm/sup 2/ chambers with small interelectrode distances. Also single wire detector cells have been built to test gas mixture lifetimes. Various admixtures of CF/sub 4/, DME, Isobutane, Ethane and Argon have been tested. Possible applications of such chambers are as beam profile monitors, position tagging of rare events and front end chambers in spectrometers.

  17. The multigap resistive plate chamber

    SciTech Connect (OSTI)

    Zeballos, E. Cerron; Crotty, I.; Hatzifotiadou, D.; Valverde, J. Lamas; Neupane, S.; Williams, M. C. S.; Zichichi, A.

    2015-02-03

    The paper describes the multigap resistive plate chamber (RPC). This is a variant of the wide gap RPC. However it has much improved time resolution, while keeping all the other advantages of the wide gap RPC design.

  18. Light diffusing fiber optic chamber

    DOE Patents [OSTI]

    Maitland, Duncan J.

    2002-01-01

    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.

  19. Observable effects of anisotropic bubble nucleation

    SciTech Connect (OSTI)

    Blanco-Pillado, Jose J.; Salem, Michael P. E-mail: salem@cosmos.phy.tufts.edu

    2010-07-01

    Our universe may have formed via bubble nucleation in an eternally-inflating background. Furthermore, the background may have a compact dimension — the modulus of which tunnels out of a metastable minimum during bubble nucleation — which subsequently grows to become one of our three large spatial dimensions. Then the reduced symmetry of the background is equivalent to anisotropic initial conditions in our bubble universe. We compute the inflationary spectrum in such a scenario and, as a first step toward understanding the effects of anisotropy, project it onto spherical harmonics. The resulting spectrum exhibits anomalous multipole correlations, their relative amplitude set by the present curvature parameter, which appear to extend to arbitrarily large multipole moments. This raises the possibility of future detection, if slow-roll inflation does not last too long within our bubble. A full understanding of the observational signal must account for the effects of background anisotropy on photon free streaming, and is left to future work.

  20. LANL researchers simulate helium bubble behavior in fusion reactors

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

    Researchers simulate helium bubble behavior LANL researchers simulate helium bubble behavior in fusion reactors A team performed simulations to understand more fully how tungsten behaves in such harsh conditions, particularly in the presence of implanted helium that forms bubbles in the material. August 4, 2015 Simulation snapshots of the helium bubble just before bursting. Colors indicate tungsten atoms (red) and helium atoms (blue). Simulation snapshots of the helium bubble just before

  1. Gravity waves from cosmic bubble collisions

    SciTech Connect (OSTI)

    Salem, Michael P.; Saraswat, Prashant; Shaghoulian, Edgar E-mail: ps88@stanford.edu

    2013-02-01

    Our local Hubble volume might be contained within a bubble that nucleated in a false vacuum with only two large spatial dimensions. We study bubble collisions in this scenario and find that they generate gravity waves, which are made possible in this context by the reduced symmetry of the global geometry. These gravity waves would produce B-mode polarization in the cosmic microwave background, which could in principle dominate over the inflationary background.

  2. Dark matter search results from the PICO-60 CF 3 I bubble chamber...

    Office of Scientific and Technical Information (OSTI)

    ; Harris, O. ; Jin, M. ; Krauss, C. B. ; Lafrenire, M. ; Laurin, M. ; Lawson, I. ; Levine, I. ; Lippincott, W. H. ; Mann, E. ; Maurya, D. ; Mitra, P. ; Neilson, R. ; Noble, A. ...

  3. Dark matter search results from the PICO-60 CF3I bubble chamber...

    Office of Scientific and Technical Information (OSTI)

    C. ; Harris, O. ; Jin, M. ; Krauss, C. B. ; Lafreniere, M. ; Laurin, M. ; Lawson, I. ; Levine, I. ; Lippincott, W. H. ; Mann, E. ; Maurya, D. ; Mitra, Pitam ; Neilson, R. ; Noble, ...

  4. ADVANCED DIAGNOSTIC TECHNIQUES FOR THREE-PHASE SLURRY BUBBLE COLUMN REACTORS (SBCR)

    SciTech Connect (OSTI)

    M.H. Al-Dahhan; M.P. Dudukovic; L.S. Fan

    2001-07-25

    This report summarizes the accomplishment made during the second year of this cooperative research effort between Washington University, Ohio State University and Air Products and Chemicals. The technical difficulties that were encountered in implementing Computer Automated Radioactive Particle Tracking (CARPT) in high pressure SBCR have been successfully resolved. New strategies for data acquisition and calibration procedure have been implemented. These have been performed as a part of other projects supported by Industrial Consortium and DOE via contract DE-2295PC95051 which are executed in parallel with this grant. CARPT and Computed Tomography (CT) experiments have been performed using air-water-glass beads in 6 inch high pressure stainless steel slurry bubble column reactor at selected conditions. Data processing of this work is in progress. The overall gas holdup and the hydrodynamic parameters are measured by Laser Doppler Anemometry (LDA) in 2 inch slurry bubble column using Norpar 15 that mimic at room temperature the Fischer Tropsch wax at FT reaction conditions of high pressure and temperature. To improve the design and scale-up of bubble column, new correlations have been developed to predict the radial gas holdup and the time averaged axial liquid recirculation velocity profiles in bubble columns.

  5. Plasma chemistry in wire chambers

    SciTech Connect (OSTI)

    Wise, J.

    1990-05-01

    The phenomenology of wire chamber aging is discussed and fundamentals of proportional counters are presented. Free-radical polymerization and plasma polymerization are discussed. The chemistry of wire aging is reviewed. Similarities between wire chamber plasma (>1 atm dc-discharge) and low-pressure rf-discharge plasmas, which have been more widely studied, are suggested. Construction and use of a system to allow study of the plasma reactions occurring in wire chambers is reported. A proportional tube irradiated by an {sup 55}Fe source is used as a model wire chamber. Condensable species in the proportional tube effluent are concentrated in a cryotrap and analyzed by gas chromatography/mass spectrometry. Several different wire chamber gases (methane, argon/methane, ethane, argon/ethane, propane, argon/isobutane) are tested and their reaction products qualitatively identified. For all gases tested except those containing methane, use of hygroscopic filters to remove trace water and oxygen contaminants from the gas resulted in an increase in the average molecular weight of the products, consistent with results from low-pressure rf-discharge plasmas. It is suggested that because water and oxygen inhibit polymer growth in the gas phase that they may also reduce polymer deposition in proportional tubes and therefore retard wire aging processes. Mechanistic implications of the plasma reactions of hydrocarbons with oxygen are suggested. Unresolved issues in this work and proposals for further study are discussed.

  6. Rest frame of bubble nucleation

    SciTech Connect (OSTI)

    Garriga, Jaume; Kanno, Sugumi; Tanaka, Takahiro E-mail: sugumi@cosmos.phy.tufts.edu

    2013-06-01

    Vacuum bubbles nucleate at rest with a certain critical size and subsequently expand. But what selects the rest frame of nucleation? This question has been recently addressed in [1] in the context of Schwinger pair production in 1+1 dimensions, by using a model detector in order to probe the nucleated pairs. The analysis in [1] showed that, for a constant external electric field, the adiabatic ''in'' vacuum of charged particles is Lorentz invariant, (and in this) case pairs tend to nucleate preferentially at rest with respect to the detector. Here, we sharpen this picture by showing that the typical relative velocity between the frame of nucleation and that of the detector is at most of order ?v ? S{sub E}{sup ?1/3} << 1. Here, S{sub E} >> 1 is the action of the instanton describing pair creation. The bound ?v coincides with the minimum uncertainty in the velocity of a non-relativistic charged particle embedded in a constant electric field. A velocity of order ?v is reached after a time interval of order ?t ? S{sub E}{sup ?1/3}r{sub 0} << r{sub 0} past the turning point in the semiclassical trajectory, where r{sub 0} is the size of the instanton. If the interaction takes place in the vicinity of the turning point, the semiclassical description of collision does not apply. Nonetheless, we find that even in this case there is still a strong asymmetry in the momentum transferred from the nucleated particles to the detector, in the direction of expansion after the turning point. We conclude that the correlation between the rest frame of nucleation and that of the detector is exceedingly sharp.

  7. Test chamber for alpha spectrometry

    DOE Patents [OSTI]

    Larsen, Robert P.

    1977-01-01

    Alpha emitters for low-level radiochemical analysis by measurement of alpha spectra are positioned precisely with respect to the location of a surface-barrier detector by means of a chamber having a removable threaded planchet holder. A pedestal on the planchet holder holds a specimen in fixed engagement close to the detector. Insertion of the planchet holder establishes an O-ring seal that permits the chamber to be pumped to a desired vacuum. The detector is protected against accidental contact and resulting damage.

  8. Continuum-scale Modeling of Hydrogen and Helium Bubble Growth...

    Office of Environmental Management (EM)

    Continuum-scale Modeling of Hydrogen and Helium Bubble Growth in Metals Continuum-scale Modeling of Hydrogen and Helium Bubble Growth in Metals Presentation from the 34th Tritium ...

  9. Electromechanical solar tracking apparatus

    DOE Patents [OSTI]

    Stromberg, Robert P.

    1981-01-01

    The invention relates to an electromechanical solar tracking device which tracks the position of the sun using paired, partially-shaded bimetallic elements.

  10. Electromechanical solar tracking apparatus

    DOE Patents [OSTI]

    Stromberg, R.P.

    The invention relates to an electromechanical solar tracking device which tracks the position of the sun using paired, partially-shaded bimetallic elements.

  11. Light diffusing fiber optic chamber (Patent) | DOEPatents

    Office of Scientific and Technical Information (OSTI)

    Country of Publication: United States Language: English Subject: light; diffusing; fiber; optic; chamber; light; diffusion; transmitting; light; target; light; transmitted; ...

  12. Sandia National Laboratories: Mode Stirred Chamber

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

    Mode Stirred Chamber The Mode Stirred chamber is essentially a large microwave oven. It consists of a metal room that serves as a high-Q chamber and a metal paddle wheel to "stir" the chamber modes. Mixing the modes in this manner allows test objects, in a single orientation to be exposed to EM energy in many different angles of incidence and polarization. Electronic susceptibility tests can be performed, or test object electromagnetic transfer functions can be determined through

  13. Competing Kinetics and He Bubble Morphology in W

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

    Sandoval, Luis; Perez, Danny; Uberuaga, Blas P.; Voter, Arthur F.

    2015-03-11

    We found that the growth process of He bubbles in W is investigated using molecular dynamics and parallel replica dynamics for growth rates spanning 6 orders of magnitude. Fast and slow growth regimes are defined relative to typical diffusion hopping times of W interstitials around the He bubble. Moreover, slow growth rates allow the diffusion of interstitials around the bubble, favoring the biased growth of the bubble towards the surface. In contrast, at fast growth rates interstitials do not have time to diffuse around the bubble, leading to a more isotropic growth and increasing the surface damage.

  14. Solar tracking system

    DOE Patents [OSTI]

    Okandan, Murat; Nielson, Gregory N.

    2016-07-12

    Solar tracking systems, as well as methods of using such solar tracking systems, are disclosed. More particularly, embodiments of the solar tracking systems include lateral supports horizontally positioned between uprights to support photovoltaic modules. The lateral supports may be raised and lowered along the uprights or translated to cause the photovoltaic modules to track the moving sun.

  15. Track 3: Exposure Hazards

    Broader source: Energy.gov [DOE]

    ISM Workshop Presentations Knoxville Convention Center, Knoxville, TN August 2009 Track 3: Exposure Hazards

  16. Track 9: Quality Assurance

    Broader source: Energy.gov [DOE]

    ISM Workshop Presentations Knoxville Convention Center, Knoxville, TN August 2009 Track 9: Quality Assurance

  17. Track 2: Worker Engagement

    Broader source: Energy.gov [DOE]

    ISM Workshop Presentations Knoxville Convention Center, Knoxville, TN August 2009 Track 2: Worker Engagement

  18. Computer Simulation of Bubble Growth in Metals Due to He

    SciTech Connect (OSTI)

    FOILES, STEPHEN M.; HOYT, JEFFREY J.

    2001-03-01

    Atomistic simulations of the growth of helium bubbles in metals are performed. The metal is represented by embedded atom method potentials for palladium. The helium bubbles are treated via an expanding repulsive spherical potential within the metal lattice. The simulations predict bubble pressures that decrease monotonically with increasing helium to metal ratios. The swelling of the material associated with the bubble growth is also computed. It is found that the rate of swelling increases with increasing helium to metal ratio consistent with experimental observations on the swelling of metal tritides. Finally, the detailed defect structure due to the bubble growth was investigated. Dislocation networks are observed to form that connect the bubbles. Unlike early model assumptions, prismatic loops between the bubbles are not retained. These predictions are compared to available experimental evidence.

  19. Shock response of He bubbles in single crystal Cu

    SciTech Connect (OSTI)

    Li, B.; Wang, L.; E, J. C.; Luo, S. N.; Ma, H. H.

    2014-12-07

    With large-scale molecular dynamics simulations, we investigate shock response of He nanobubbles in single crystal Cu. For sufficient bubble size or internal pressure, a prismatic dislocation loop may form around a bubble in unshocked Cu. The internal He pressure helps to stabilize the bubble against plastic deformation. However, the prismatic dislocation loops may partially heal but facilitate nucleation of new shear and prismatic dislocation loops. For strong shocks, the internal pressure also impedes internal jetting, while a bubble assists local melting; a high speed jet breaks a He bubble into pieces dispersed among Cu. Near-surface He bubbles may burst and form high velocity ejecta containing atoms and small fragments, while the ejecta velocities do not follow the three-dimensional Maxwell-Boltzmann distributions expected for thermal equilibrium. The biggest fragment size deceases with increasing shock strength. With a decrease in ligament thickness or an increase in He bubble size, the critical shock strength required for bubble bursting decreases, while the velocity range, space extension and average velocity component along the shock direction, increase. Small bubbles are more efficient in mass ejecting. Compared to voids and perfect single crystal Cu, He bubbles have pronounced effects on shock response including bubble/void collapse, Hugoniot elastic limit (HEL), deformation mechanisms, and surface jetting. HEL is the highest for perfect single crystal Cu with the same orientations, followed by He bubbles without pre-existing prismatic dislocation loops, and then voids. Complete void collapse and shear dislocations occur for embedded voids, as opposed to partial collapse, and shear and possibly prismatic dislocations for He bubbles. He bubbles lower the threshhold shock strength for ejecta formation, and increase ejecta velocity and ejected mass.

  20. NIF Target Chamber Dedicated | National Nuclear Security Administration |

    National Nuclear Security Administration (NNSA)

    (NNSA) NIF Target Chamber Dedicated NIF Target Chamber Dedicated Livermore, CA Secretary Richardson dedicates the National Ignition Facility target chamber at DOE's Lawrence Livermore National Laboratory

  1. Tests of a single-wire drift chamber for possible use in low intensity beams

    SciTech Connect (OSTI)

    Haggerty, H.

    1986-02-01

    A single cell drift chamber with two dimensional readout has been evaluated as a candidate for reliable and inexpensive momentum tagging of low intensity calibration beams. Charges induced on shaped cathode pads allow a measurement of the coordinate parallel to the wire, while the drift time allows a measurement of the coordinate perpendicular to the wire. Two chamber orientations were used during the tests. In one the chambers were arranged with their wires parallel. In this case the intrinsic resolution of the chambers was measured; the top and bottom cells were used to define a track coordinate and this was compared to the coordinate in the middle chamber. To see if either of the two coordinate measurements is linear in real space, the chambers were rearranged to the second orientation, with the middle chamber rotated 90/sup 0/. The drift time was plotted against the charge ratio. The conclusion drawn from this study is that while the drift time measurement has adequate resolution, the charge ratio measurement is not a viable option for beam line use. (LEW)

  2. Scalings for radiation from plasma bubbles

    SciTech Connect (OSTI)

    Thomas, A. G. R.

    2010-05-15

    In this paper, electron trajectories are studied analytically in the rest frame of a plasma bubble using nonevolving, linear, radial electric and azimuthal magnetic fields in a spherical structure. The electron motion is broken into two distinct periods; one where it orbits around the periphery to the rear of the bubble, and one where it performs oscillations within the bubble interior. By using the first period as an initial condition for the second, general scalings are developed for the x-ray radiation produced by the electron oscillations. The equations are also analyzed to give self-trapping conditions for the electron and to examine the sensitivity of the transverse momentum to small variations from an orbit that is a circular arc. The scalings are in reasonable agreement with recent experiments on x-ray generation and predict a peak spectral brightness of S{approx_equal}6x10{sup 27} photons/s mrad mm 0.1%BW of radiation with a critical energy of 300 MeV using a single stage accelerator driven by a 120 PW laser.

  3. Allostery through protein-induced DNA bubbles

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

    Traverso, Joseph J.; Manoranjan, Valipuram S.; Bishop, A. R.; Rasmussen, Kim Ø.; Voulgarakis, Nikolaos K.

    2015-03-12

    Allostery through DNA is increasingly recognized as an important modulator of DNA functions. Here, we show that the coalescence of protein-induced DNA bubbles can mediate allosteric interactions that drive protein aggregation. We propose that such allostery may regulate DNA's flexibility and the assembly of the transcription machinery. Mitochondrial transcription factor A (TFAM), a dual-function protein involved in mitochondrial DNA (mtDNA) packaging and transcription initiation, is an ideal candidate to test such a hypothesis owing to its ability to locally unwind the double helix. Numerical simulations demonstrate that the coalescence of TFAM-induced bubbles can explain experimentally observed TFAM oligomerization. The resultingmore » melted DNA segment, approximately 10 base pairs long, around the joints of the oligomers act as flexible hinges, which explains the efficiency of TFAM in compacting DNA. Since mitochondrial polymerase (mitoRNAP) is involved in melting the transcription bubble, TFAM may use the same allosteric interaction to both recruit mitoRNAP and initiate transcription.« less

  4. A bubble detection system for propellant filling pipeline

    SciTech Connect (OSTI)

    Wen, Wen; Zong, Guanghua; Bi, Shusheng

    2014-06-15

    This paper proposes a bubble detection system based on the ultrasound transmission method, mainly for probing high-speed bubbles in the satellite propellant filling pipeline. First, three common ultrasonic detection methods are compared and the ultrasound transmission method is used in this paper. Then, the ultrasound beam in a vertical pipe is investigated, suggesting that the width of the beam used for detection is usually smaller than the internal diameter of the pipe, which means that when bubbles move close to the pipe wall, they may escape from being detected. A special device is designed to solve this problem. It can generate the spiral flow to force all the bubbles to ascend along the central line of the pipe. In the end, experiments are implemented to evaluate the performance of this system. Bubbles of five different sizes are generated and detected. Experiment results show that the sizes and quantity of bubbles can be estimated by this system. Also, the bubbles of different radii can be distinguished from each other. The numerical relationship between the ultrasound attenuation and the bubble radius is acquired and it can be utilized for estimating the unknown bubble size and measuring the total bubble volume.

  5. Mesoscale modeling of intergranular bubble percolation in nuclear fuels

    SciTech Connect (OSTI)

    Millett, Paul C.; Tonks, Michael; Biner, S. B.

    2012-04-15

    Phase-field simulations are used to examine the variability of intergranular fission gas bubble growth and percolation on uranium dioxide grain boundaries on a mesoscopic length scale. Three key parameters are systematically varied in this study: the contact angle (or dihedral angle) defining the bubble shape, the initial bubble density on the grain boundary plane, and the ratio of the gas diffusivity on the grain boundary versus the grain interiors. The simulation results agree well with previous experimental data obtained for bubble densities and average bubble areas during coalescence events. Interestingly, the rate of percolation is found to be highly variable, with a large dependency on the contact angle and the initial bubble density and little-to-no dependency on the grain boundary gas diffusivity.

  6. MESOSCALE MODELING OF INTERGRANULAR BUBBLE PERCOLATION IN NUCLEAR FUELS

    SciTech Connect (OSTI)

    Paul C. Millett; Michael Tonks; S. B. Biner

    2012-04-01

    Phase-field simulations are used to examine the variability of intergranular fission gas bubble growth and percolation on uranium dioxide grain boundaries on a mesoscopic length scale. Three key parameters are systematically varied in this study: the contact angle (or dihedral angle) defining the bubble shape, the initial bubble density on the grain boundary plane, and the ratio of the gas diffusivity on the grain boundary versus the grain interiors. The simulation results agree well with previous experimental data obtained for bubble densities and average bubble areas during coalescence events. Interestingly, the rate of percolation is found to be highly variable, with a large dependency on the contact angle and the initial bubble density, and little-to-no dependency on the grain boundary gas diffusivity.

  7. Solar tracking apparatus

    DOE Patents [OSTI]

    Hammons, Burrell E.

    1980-01-01

    The invention relates to a solar tracking device which tracks the position of the sun using paired, partially-shaded photocells. Auxiliary photocells are used for initial acquisition of the sun and for the suppression of false tracking when the sun is obscured by clouds.

  8. Solar tracking apparatus

    DOE Patents [OSTI]

    Hammons, B.E.

    The invention relates to a solar tracking device which tracks the position of the sun using paired, partially-shaded photocells. Auxilliary photocells are used for initial acquisition of the sun and for the suppression of false tracking when the sun is obscured by clouds.

  9. 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 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

  10. Fluidized wall for protecting fusion chamber walls

    DOE Patents [OSTI]

    Maniscalco, James A.; Meier, Wayne R.

    1982-01-01

    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.

  11. Bubbles Hot Spring Pool & Spa Low Temperature Geothermal Facility...

    Open Energy Info (EERE)

    Spa Low Temperature Geothermal Facility Facility Bubbles Hot Spring Sector Geothermal energy Type Pool and Spa Location Catron County, New Mexico Coordinates 34.1515173,...

  12. Simultaneous observation of nascent plasma and bubble induced...

    Office of Scientific and Technical Information (OSTI)

    in water with various pulse durations Citation Details In-Document Search Title: Simultaneous observation of nascent plasma and bubble induced by laser ablation in water with ...

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

    Office of Science (SC) Website

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

  14. Stationary bubbles and their tunneling channels toward trivial...

    Office of Scientific and Technical Information (OSTI)

    We investigate the dynamics and tunneling channels of true vacuum bubbles for various tensions. In particular, in line with the idea of superposition of geometries, we build a ...

  15. Detecting vapour bubbles in simulations of metastable water

    SciTech Connect (OSTI)

    Gonzlez, Miguel A.; Abascal, Jose L. F.; Valeriani, Chantal E-mail: cvaleriani@quim.ucm.es; Menzl, Georg; Geiger, Philipp; Dellago, Christoph E-mail: cvaleriani@quim.ucm.es; Aragones, Juan L.; Caupin, Frederic

    2014-11-14

    The investigation of cavitation in metastable liquids with molecular simulations requires an appropriate definition of the volume of the vapour bubble forming within the metastable liquid phase. Commonly used approaches for bubble detection exhibit two significant flaws: first, when applied to water they often identify the voids within the hydrogen bond network as bubbles thus masking the signature of emerging bubbles and, second, they lack thermodynamic consistency. Here, we present two grid-based methods, the M-method and the V-method, to detect bubbles in metastable water specifically designed to address these shortcomings. The M-method incorporates information about neighbouring grid cells to distinguish between liquid- and vapour-like cells, which allows for a very sensitive detection of small bubbles and high spatial resolution of the detected bubbles. The V-method is calibrated such that its estimates for the bubble volume correspond to the average change in system volume and are thus thermodynamically consistent. Both methods are computationally inexpensive such that they can be used in molecular dynamics and Monte Carlo simulations of cavitation. We illustrate them by computing the free energy barrier and the size of the critical bubble for cavitation in water at negative pressure.

  16. Helium Nano-Bubble Evolution in Aging Metal Tritides

    SciTech Connect (OSTI)

    Cowgill, Donald F.

    2005-07-15

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

  17. Internal combustion engine with rotary combustion chamber

    SciTech Connect (OSTI)

    Hansen, C.N.; Cross, P.C.

    1986-09-23

    This patent describes an internal combustion engine comprising: a block having at least one cylindrical wall surrounding a piston chamber, piston means located in the piston chamber means operable to reciprocate the piston means in the chamber, head means mounted on the block covering the chamber. The head means has an air and fuel intake passage, and exhaust gas passage, a rotary valve assembly operatively associated with the head means for controlling the flow of air and fuel into the rotary valve assembly and piston chamber and the flow of exhaust gas from rotary valve assembly and the piston chamber. The means has a housing with a bore open to the piston chamber accommodating the rotary valve assembly, the valve assembly comprising a cylindrical sleeve located in the bore, the sleeve having an inner surface, an ignition hole, and intake and exhaust ports aligned with the intake passage and exhaust gas passage, spark generating means mounted on the housing operable to generate a spark. The rotatable valving means is located within the sleeve for controlling the flow of air and fuel into the rotary valve assembly and piston chamber and the flow of exhaust gases out of the rotary valve assembly and piston chamber.

  18. V&V Of CFD Modeling Of The Argonne Bubble Experiment: FY15 Summary Report

    SciTech Connect (OSTI)

    Hoyt, Nathaniel C.; Wardle, Kent E.; Bailey, James L.; Basavarajappa, Manjunath

    2015-09-30

    In support of the development of accelerator-driven production of the fission product Mo 99, computational fluid dynamics (CFD) simulations of an electron-beam irradiated, experimental-scale bubble chamber have been conducted in order to aid in interpretation of existing experimental results, provide additional insights into the physical phenomena, and develop predictive thermal hydraulic capabilities that can be applied to full-scale target solution vessels. Toward that end, a custom hybrid Eulerian-Eulerian-Lagrangian multiphase solver was developed, and simulations have been performed on high-resolution meshes. Good agreement between experiments and simulations has been achieved, especially with respect to the prediction of the maximum temperature of the uranyl sulfate solution in the experimental vessel. These positive results suggest that the simulation methodology that has been developed will prove to be suitable to assist in the development of full-scale production hardware.

  19. The Drift Chamber for the Experiment to Study the Nature of the Confinement

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

    Berdnikov, Vladimir V.; Somov, S. V.; Pentchev, Lubomir; Zihlmann, Benedikt

    2015-01-01

    The GlueX experiment was designed to search for hybrid mesons with exotic quantum numbers using a beam of linearly polarized photons incident on a liquid hydrogen target. The spectrum of these states and their mass splitting from normal mesons may yield information on confinement. The description of the GlueX spectrometer and Forward Drift Chambers (FDC) as a part of track reconstruction system is presented in the text. FDC‘s are multiwire chambers with cathode and anode read-out. The system allows reconstructing tracks of charged particles with ~200mkm accuracy with angles from 20° up to 1°. One of the detector features ismore » 1.64% X0 material amount in the active area. The cathode gain calibration procedure is presented. The results of such calibration using cosmic data and beam data are presented as well.« less

  20. Interfacial area transport in bubbly flow

    SciTech Connect (OSTI)

    Ishii, M.; Wu, Q.; Revankar, S.T.

    1997-12-31

    In order to close the two-fluid model for two-phase flow analyses, the interfacial area concentration needs to be modeled as a constitutive relation. In this study, the focus was on the investigation of the interfacial area concentration transport phenomena, both theoretically and experimentally. The interfacial area concentration transport equation for air-water bubbly up-flow in a vertical pipe was developed, and the models for the source and sink terms were provided. The necessary parameters for the experimental studies were identified, including the local time-averaged void fraction, interfacial area concentration, bubble interfacial velocity, liquid velocity and turbulent intensity. Experiments were performed with air-water mixture at atmospheric pressure. Double-sensor conductivity probe and hot-film probe were employed to measure the identified parameters. With these experimental data, the preliminary model evaluation was carried out for the simplest form of the developed interfacial area transport equation, i.e., the one-dimensional transport equation.

  1. Compact ion chamber based neutron detector

    SciTech Connect (OSTI)

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

    2015-10-27

    A directional neutron detector has an ion chamber formed in a dielectric material; a signal electrode and a ground electrode formed in the ion chamber; a neutron absorbing material filling the ion chamber; readout circuitry which is electrically coupled to the signal and ground electrodes; and a signal processor electrically coupled to the readout circuitry. The ion chamber has a pair of substantially planar electrode surfaces. The chamber pressure of the neutron absorbing material is selected such that the reaction particle ion trail length for neutrons absorbed by the neutron absorbing material is equal to or less than the distance between the electrode surfaces. The signal processor is adapted to determine a path angle for each absorbed neutron based on the rise time of the corresponding pulse in a time-varying detector signal.

  2. Compact ion chamber based neutron detector

    SciTech Connect (OSTI)

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

    2015-11-05

    A directional neutron detector has an ion chamber formed in a dielectric material; a signal electrode and a ground electrode formed in the ion chamber; a neutron absorbing material filling the ion chamber; readout circuitry which is electrically coupled to the signal and ground electrodes; and a signal processor electrically coupled to the readout circuitry. The ion chamber has a pair of substantially planar electrode surfaces. The chamber pressure of the neutron absorbing material is selected such that the reaction particle ion trail length for neutrons absorbed by the neutron absorbing material is equal to or less than the distance between the electrode surfaces. The signal processor is adapted to determine a path angle for each absorbed neutron based on the rise time of the corresponding pulse in a time-varying detector signal.

  3. Ionization-chamber smoke detector system

    DOE Patents [OSTI]

    Roe, Robert F.

    1976-10-19

    This invention relates to an improved smoke-detection system of the ionization-chamber type. In the preferred embodiment, the system utilizes a conventional detector head comprising a measuring ionization chamber, a reference ionization chamber, and a normally non-conductive gas triode for discharging when a threshold concentration of airborne particulates is present in the measuring chamber. The improved system is designed to reduce false alarms caused by fluctuations in ambient temperature. Means are provided for periodically firing the gas discharge triode and each time recording the triggering voltage required. A computer compares each triggering voltage with its predecessor. The computer is programmed to energize an alarm if the difference between the two compared voltages is a relatively large value indicative of particulates in the measuring chamber and to disregard smaller differences typically resulting from changes in ambient temperature.

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

    SciTech Connect (OSTI)

    Cowgill, Donald F.

    2004-05-01

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

  5. PHASE-FIELD SIMULATION OF IRRADIATED METALS: PART II: GAS BUBBLE...

    Office of Scientific and Technical Information (OSTI)

    Finally, intergranular bubble characteristics such as shape, pinning energy on GB motion, and bubble density are investigated. Authors: Paul C Millett ; Anter El-Azab Publication ...

  6. RADIATION MONITOR CONTAINING TWO CONCENTRIC IONIZATION CHAMBERS AND MEANS FOR INSULATING THE SEPARATE CHAMBERS

    DOE Patents [OSTI]

    Braestrup, C.B.; Mooney, R.T.

    1964-01-21

    This invention relates to a portable radiation monitor containing two concentric ionization chambers which permit the use of standard charging and reading devices. It is particularly adapted as a personnel x-ray dosimeter and to this end comprises a small thin walled, cylindrical conductor forming an inner energy dependent chamber, a small thin walled, cylindrical conductor forming an outer energy independent chamber, and polymeric insulation means which insulates said chambers from each other and holds the chambers together with exposed connections in a simple, trouble-free, and compact assembly substantially without variation in directional response. (AEC)

  7. Micro-Bubble Experiments at the Van de Graaff Accelerator

    SciTech Connect (OSTI)

    Sun, Z. J.; Wardle, Kent E.; Quigley, K. J.; Gromov, Roman; Youker, A. J.; Makarashvili, Vakhtang; Bailey, James; Stepinski, D. C.; Chemerisov, S. D.; Vandegrift, G. F.

    2015-02-01

    In order to test and verify the experimental designs at the linear accelerator (LINAC), several micro-scale bubble ("micro-bubble") experiments were conducted with the 3-MeV Van de Graaff (VDG) electron accelerator. The experimental setups included a square quartz tube, sodium bisulfate solution with different concentrations, cooling coils, gas chromatography (GC) system, raster magnets, and two high-resolution cameras that were controlled by a LabVIEW program. Different beam currents were applied in the VDG irradiation. Bubble generation (radiolysis), thermal expansion, thermal convection, and radiation damage were observed in the experiments. Photographs, videos, and gas formation (O2 + H2) data were collected. The micro-bubble experiments at VDG indicate that the design of the full-scale bubble experiments at the LINAC is reasonable.

  8. Sun tracking controller

    SciTech Connect (OSTI)

    Menser, H.K.; Newcomb, R.D.

    1981-11-24

    An apparatus is described which controls the electric tracking motors of solar energy collectors and other solar devices which are adapted to be aimed at the sun.

  9. Target motion tracking with a scanned particle beam

    SciTech Connect (OSTI)

    Bert, Christoph; Saito, Nami; Schmidt, Alexander; Chaudhri, Naved; Schardt, Dieter; Rietzel, Eike

    2007-12-15

    Treatment of moving targets with scanned particle beams results in local over- and under-dosage due to interplay of beam and target motion. To mitigate the impact of respiratory motion, a motion tracking system has been developed and integrated in the therapy control system at Gesellschaft fuer Schwerionenforschung. The system adapts pencil beam positions as well as the beam energy according to target motion to irradiate the planned position. Motion compensation performance of the tracking system was assessed by measurements with radiographic films and a 3D array of 24 ionization chambers. Measurements were performed for stationary detectors and moving detectors using the tracking system. Film measurements showed comparable homogeneity inside the target area. Relative differences of 3D dose distributions within the target volume were 1{+-}2% with a maximum of 4%. Dose gradients and dose to surrounding areas were in good agreement. The motion tracking system successfully preserved dose distributions delivered to moving targets and maintained target conformity.

  10. Inertial confinement fusion based on the ion-bubble trigger

    SciTech Connect (OSTI)

    Jafari, S. Nilkar, M.; Ghasemizad, A.; Mehdian, H.

    2014-10-15

    Triggering the ion-bubble in an inertial confinement fusion, we have developed a novel scheme for the fast ignition. This scheme relies on the plasma cavitation by the wake of an intense laser pulse to generate an ion-bubble. The bubble acts both as an intense electron accelerator and as an electron wiggler. Consequently, the accelerated electrons trapped in the bubble can emit an intense tunable laser light. This light can be absorbed by an ablation layer on the outside surface of the ignition capsule, which subsequently drills it and thereby produces a guide channel in the pellet. Finally, the relativistic electron beam created in the bubble is guided through the channel to the high density core igniting the fusion fuel. The normalized beam intensity and beam energy required for triggering the ignition have been calculated when core is heated by the e-beam. In addition, through solving the momentum transfer, continuity and wave equations, a dispersion relation for the electromagnetic and space-charge waves has been analytically derived. The variations of growth rate with the ion-bubble density and electron beam energy have been illustrated. It is found that the growth rates of instability are significantly controlled by the ions concentration and the e-beam energy in the bubble.

  11. Large scale tracking algorithms.

    SciTech Connect (OSTI)

    Hansen, Ross L.; Love, Joshua Alan; Melgaard, David Kennett; Karelitz, David B.; Pitts, Todd Alan; Zollweg, Joshua David; Anderson, Dylan Z.; Nandy, Prabal; Whitlow, Gary L.; Bender, Daniel A.; Byrne, Raymond Harry

    2015-01-01

    Low signal-to-noise data processing algorithms for improved detection, tracking, discrimination and situational threat assessment are a key research challenge. As sensor technologies progress, the number of pixels will increase signi cantly. This will result in increased resolution, which could improve object discrimination, but unfortunately, will also result in a significant increase in the number of potential targets to track. Many tracking techniques, like multi-hypothesis trackers, suffer from a combinatorial explosion as the number of potential targets increase. As the resolution increases, the phenomenology applied towards detection algorithms also changes. For low resolution sensors, "blob" tracking is the norm. For higher resolution data, additional information may be employed in the detection and classfication steps. The most challenging scenarios are those where the targets cannot be fully resolved, yet must be tracked and distinguished for neighboring closely spaced objects. Tracking vehicles in an urban environment is an example of such a challenging scenario. This report evaluates several potential tracking algorithms for large-scale tracking in an urban environment.

  12. TRACKED VEHICLE Rev 75

    SciTech Connect (OSTI)

    Raby, Eric Y.

    2007-05-08

    Revision 75 of the Tracked Vehicle software is a soft real-time simulation of a differentially steered, tracked mobile robot, which, because of the track flippers, resembles the iRobot PackBot (http://www.irobot.com/). Open source libraries are used for the physics engine (http://www.ode.org/), the display and user interface (http://www.mathies.com/cpw/), and the program command line and configuration file parameters (http://www.boost.org/). The simulation can be controlled by a USB joystick or the keyboard. The configuration file contains demonstration model parameters of no particular vehicle. This simulation can be used as a starting point for those doing tracked vehicle simulations. This simulation software is essentially a research tool which can be modified and adapted for certain types of tracked vehicle research. An open source license allows an individual researchers to tailor the code to their specific research needs.

  13. TRACKED VEHICLE Rev 75

    Energy Science and Technology Software Center (OSTI)

    2007-05-08

    Revision 75 of the Tracked Vehicle software is a soft real-time simulation of a differentially steered, tracked mobile robot, which, because of the track flippers, resembles the iRobot PackBot (http://www.irobot.com/). Open source libraries are used for the physics engine (http://www.ode.org/), the display and user interface (http://www.mathies.com/cpw/), and the program command line and configuration file parameters (http://www.boost.org/). The simulation can be controlled by a USB joystick or the keyboard. The configuration file contains demonstration model parametersmore » of no particular vehicle. This simulation can be used as a starting point for those doing tracked vehicle simulations. This simulation software is essentially a research tool which can be modified and adapted for certain types of tracked vehicle research. An open source license allows an individual researchers to tailor the code to their specific research needs.« less

  14. China New Energy Chamber of Commerce CNECC | Open Energy Information

    Open Energy Info (EERE)

    Chamber of Commerce CNECC Jump to: navigation, search Name: China New Energy Chamber of Commerce (CNECC) Place: Beijing, Beijing Municipality, China Zip: 100052 Product: A Chinese...

  15. Gas Electron Multiplier (GEM) Chamber Characteristics Test (Technical...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Gas Electron Multiplier (GEM) Chamber Characteristics Test Citation Details In-Document Search Title: Gas Electron Multiplier (GEM) Chamber Characteristics Test ...

  16. Sealable femtoliter chamber arrays for cell-free biology (Journal...

    Office of Scientific and Technical Information (OSTI)

    Sealable femtoliter chamber arrays for cell-free biology Prev Next Title: Sealable femtoliter chamber arrays for cell-free biology You are accessing a document from the ...

  17. Evolution of silicic magma chambers and their relationship to...

    Office of Scientific and Technical Information (OSTI)

    Conference: Evolution of silicic magma chambers and their relationship to basaltic volcanism Citation Details In-Document Search Title: Evolution of silicic magma chambers and ...

  18. He bubble coarsening by migration and coalescence in annealed...

    Office of Scientific and Technical Information (OSTI)

    Title: He bubble coarsening by migration and coalescence in annealed Pu-Ga alloys Authors: Jeffries, J R ; Wall, M A ; Moore, K T ; Schwartz, A J Publication Date: 2010-09-29 OSTI ...

  19. Gravitational wave generation from bubble collisions in first...

    Office of Scientific and Technical Information (OSTI)

    In our approach, we provide a model for the bubble velocity power spectrum, suitable for ... We provide analytical formulas for the peak frequency and the shape of the spectrum which ...

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

    SciTech Connect (OSTI)

    Osetskiy, Yury N.; Stoller, Roger E.

    2015-06-03

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

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

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

    Osetskiy, Yury N.; Stoller, Roger E.

    2015-06-03

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

  2. Energy Tracking Software Platform

    SciTech Connect (OSTI)

    Ryan Davis; Nathan Bird; Rebecca Birx; Hal Knowles

    2011-04-04

    Acceleration has created an interactive energy tracking and visualization platform that supports decreasing electric, water, and gas usage. Homeowners have access to tools that allow them to gauge their use and track progress toward a smaller energy footprint. Real estate agents have access to consumption data, allowing for sharing a comparison with potential home buyers. Home builders have the opportunity to compare their neighborhood's energy efficiency with competitors. Home energy raters have a tool for gauging the progress of their clients after efficiency changes. And, social groups are able to help encourage members to reduce their energy bills and help their environment. EnergyIT.com is the business umbrella for all energy tracking solutions and is designed to provide information about our energy tracking software and promote sales. CompareAndConserve.com (Gainesville-Green.com) helps homeowners conserve energy through education and competition. ToolsForTenants.com helps renters factor energy usage into their housing decisions.

  3. MATERIAL TRACKING USING LANMAS

    SciTech Connect (OSTI)

    Armstrong, F.

    2010-06-07

    LANMAS is a transaction-based nuclear material accountability software product developed to replace outdated and legacy accountability systems throughout the DOE. The core underlying purpose of LANMAS is to track nuclear materials inventory and report transactions (movement, mixing, splitting, decay, etc.) to the Nuclear Materials Management and Safeguards System (NMMSS). While LANMAS performs those functions well, there are many additional functions provided by the software product. As a material is received onto a site or created at a site, its entire lifecycle can be tracked in LANMAS complete to its termination of safeguards. There are separate functions to track material movements between and within material balance areas (MBAs). The level of detail for movements within a MBA is configurable by each site and can be as high as a site designation or as detailed as building/room/rack/row/position. Functionality exists to track the processing of materials, either as individual items or by modeling a bulk process as an individual item to track inputs and outputs from the process. In cases where sites have specialized needs, the system is designed to be flexible so that site specific functionality can be integrated into the product. This paper will demonstrate how the software can be used to input material into an account and track it to its termination of safeguards.

  4. Combustion chamber, especially for gas turbines

    SciTech Connect (OSTI)

    Meyer, F.

    1980-04-29

    A combustion chamber is disclosed that has an end-wall at the inlet side and an axial inlet opening, which is adjoined by an essentially cylindrical wall section provided with secondary air inlet openings; the end-wall thereby adjoins the inlet opening approximately hemispherically shaped with a sphere diameter which is larger than the diameter of the cylindrical wall section while the adjoining combustion chamber portion is again reduced to the adjacent cylindrical wall section by way of a combustion chamber wall substantially continuing the sphere shape; the fuel injection device is provided upstream of the inlet opening which injects fuel into the inlet opening, itself covered off by a deflection means.

  5. Track 10: Feedback and Improvement

    Broader source: Energy.gov [DOE]

    ISM Workshop Presentations Knoxville Convention Center, Knoxville, TN August 2009 Track 10: Feedback and Improvement

  6. Miniature reaction chamber and devices incorporating same

    DOE Patents [OSTI]

    Mathies, Richard A.; Woolley, Adam T.

    2000-10-17

    The present invention generally relates to miniaturized devices for carrying out and controlling chemical reactions and analyses. In particular, the present invention provides devices which have miniature temperature controlled reaction chambers for carrying out a variety of synthetic and diagnostic applications, such as PCR amplification, nucleic acid hybridization, chemical labeling, nucleic acid fragmentation and the like.

  7. Controlled Document Tracking Software

    Energy Science and Technology Software Center (OSTI)

    1992-08-24

    MANTRACK is an automated, controlled document tracking system which does the following and reduces staff time required to perform these tasks: generates transmittal letters/receipts for every controlled copy issued (merged from a current distribution list), tracks the return of transmittal receipts, facilitates the check-in of the large number of transmittal receipts returned (using a barcode reader), generates a reminder list which prompts the cyclic review and evaluation of existing documents, generates overdue reminders for themore » return of past-due transmittal receipts, tracks the number of Procedure Change Directives (PCD) currently in effect for each procedure, generates and maintains current distribution lists for each document, generates a current table of contents when updates to the document (usually a procedure manual) are made.« less

  8. Investigations of protons passing through the CR-39/PM-355 type of solid state nuclear track detectors

    SciTech Connect (OSTI)

    Malinowska, A.; Szyd?owski, A.; Jask?a, M.; Korman, A.; Kuk, M.; Sartowska, B.; Kuehn, T.

    2013-07-15

    Solid State Nuclear Track Detectors of the CR-39/PM-355 type were irradiated with protons with energies in the range from 0.2 to 8.5 MeV. Their intensities and energies were controlled by a Si surface barrier detector located in an accelerator scattering chamber. The ranges of protons with energies of 67 MeV were comparable to the thickness of the PM-355 track detectors. Latent tracks in the polymeric detectors were chemically etched under standard conditions to develop the tracks. Standard optical microscope and scanning electron microscopy techniques were used for surface morphology characterization.

  9. High-voltage crowbar protection for the large CDF axial drift chamber

    SciTech Connect (OSTI)

    Binkley, M.; Mukherjee, A.; Stuermer, W.; Wagner, R.L.; /Fermilab

    2004-01-01

    The Central Outer Tracker (COT) is a big cylindrical drift chamber that provides charged particle tracking for the Collider Detector at Fermilab experiment. To protect the COT, the large stored energy in the high voltage system needs to be removed quickly when a problem is sensed. For the high voltage switch, a special-order silicon-controlled-rectifier was chosen over more readily available integrated gate bipolar transistors because of layout and reliability questions. The considerations concerning the high voltage switch, the prototype performance, and the experience of more than two years of running are described.

  10. RES Energy Track

    Broader source: Energy.gov [DOE]

    ​The Office of Indian Energy is hosting an Energy Track featuring breakout sessions on a variety of topics, including workforce development, energy technology, and capacity building, to help tribal energy leaders and professionals make informed decisions about energy projects.

  11. Solar tracking device

    SciTech Connect (OSTI)

    Wyland, R.R.

    1981-01-20

    A solar tracking device having a plurality of reflector banks for reflecting the sun rays onto collector tubes and heating a fluid circulated therethrough. The reflector banks synchronized to follow the sun during the daily and yearly cycle of the earth as the earth orbits around the sun. The device by accurately following the sun provides a more efficient means of collecting solar energy.

  12. Steam bubble collapse induced water hammer in draining pipes

    SciTech Connect (OSTI)

    Griffith, P.; Silva, R.J.

    1991-08-01

    When hot steam replaces cold condensate in a horizontal or almost horizontal pipe, a steam bubble collapse induced water hammer often results. The effect of condensate drainage velocity and pipe declination on the incidence of steam bubble collapse induced water hammer is investigated experimentally. Declining the pipe more than 2.4{degrees} allows drainage velocities up to 3 ft/sec (1m/s) in a two inch (5 cm) pipe without water hammer. A semi-empirical theory allows extrapolation to other pressures, pipe sizes and inclinations. 4 refs.

  13. High-speed photography of the bubble generated by an airgun ...

    Office of Scientific and Technical Information (OSTI)

    Estimations of the bubble-wall velocity and bubble radius estimated from high-speed film sequences are also presented, and are compared with modeled results. The deviation between ...

  14. Gas Injection Apparatus for Vacuum Chamber

    SciTech Connect (OSTI)

    Almabouada, F.; Louhibi, D.; Hamici, M.

    2011-12-26

    We present in this article a gas injection apparatus which comprises the gas injector and its electronic command for vacuum chamber applications. Some of these applications are thin-film deposition by a pulsed laser deposition (PLD) or a cathodic arc deposition (arc-PVD) and the plasma generation. The electronic part has been developed to adjust the flow of the gas inside the vacuum chamber by controlling both of the injector's opening time and the repetition frequency to allow a better gas flow. In this case, the system works either on a pulsed mode or a continuous mode for some applications. In addition, the repetition frequency can be synchronised with a pulsed laser by an external signal coming from the laser, which is considered as an advantage for users. Good results have been obtained using the apparatus and testing with Argon and Nitrogen gases.

  15. Combustion chamber for a gas turbine

    SciTech Connect (OSTI)

    Holzapfel, I.

    1982-09-21

    A combustion chamber for a gas turbine, in particular for motor vehicles, with an atomizer nozzle for the fuel fed to a prechamber, in which the inlet cross section for the primary air is changed by the longitudinal movement of a deflection member extending through the inlet opening of the combustion chamber. The deflection member serves as a flame holder for the stabilization of the combustion in the primary air zone while the air-atomizing nozzle is constructed ring-shaped and is provided with swirl slots in such a manner that the mixture of the fuel and of the atomizing air enters as an annular jet the primary air inlet channel, impinges approximately perpendicularly onto the primary air flow, penetrates the same and uniformly mixes with the same on its way to the inlet into the primary zone. The quantity of the primary air to be supplied is thereby automatically adjustable.

  16. OSTIblog Articles in the Tennessee Chamber of Commerce and Industry...

    Office of Scientific and Technical Information (OSTI)

    We are proud to note that OSTI was featured in the Tennessee Chamber of Commerce & Industry'ssummer issue of its newsletter, the Business Insider. The Chamber says that OSTI and ...

  17. Minority Chamber of Commerce "How to do Business with Federal...

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

    Minority Chamber of Commerce "How to do Business with Federal Government" Minority Chamber of Commerce "How to do Business with Federal Government" October 29, 2015 9:00AM to...

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

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

    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...

  19. Automated soil gas monitoring chamber (Patent) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Title: Automated soil gas monitoring chamber A chamber for trapping soil gases as they evolve from the soil without disturbance to the soil and to the natural microclimate within ...

  20. Turkey Track Wind Farm | Open Energy Information

    Open Energy Info (EERE)

    Track Wind Farm Jump to: navigation, search Name Turkey Track Wind Farm Facility Turkey Track Wind Farm Sector Wind energy Facility Type Commercial Scale Wind Facility Status In...

  1. Tracking the Elusive QOOH Radical

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

    Tracking Santa With Our Eyes in the Sky Tracking Santa With Our Eyes in the Sky December 24, 2013 - 10:00am Addthis The Energy Department's Los Alamos National Lab is tracking Santa Claus as he circles the globe the night before Christmas. The Energy Department's Los Alamos National Lab is tracking Santa Claus as he circles the globe the night before Christmas. Michael Hess Michael Hess Former Digital Communications Specialist, Office of Public Affairs Every year since 1998, the Energy

  2. PARTICLE BEAM TRACKING CIRCUIT

    DOE Patents [OSTI]

    Anderson, O.A.

    1959-05-01

    >A particle-beam tracking and correcting circuit is described. Beam induction electrodes are placed on either side of the beam, and potentials induced by the beam are compared in a voltage comparator or discriminator. This comparison produces an error signal which modifies the fm curve at the voltage applied to the drift tube, thereby returning the orbit to the preferred position. The arrangement serves also to synchronize accelerating frequency and magnetic field growth. (T.R.H.)

  3. Color-based tracking of plasma dust particles

    SciTech Connect (OSTI)

    Villamayor, Michelle Marie S. Soriano, Maricor N.; Ramos, Henry J.; Kato, Shuichi; Wada, Motoi

    2014-02-15

    Color-based tracking to observe agglomeration of deposited particles inside a compact planar magnetron during plasma discharge was done by creating high dynamic range (HDR) images of photos captured by a Pentax K10D digital camera. Carbon erosion and redeposition was also monitored using the technique. The HDR images were subjected to a chromaticity-based constraint discoloration inside the plasma chamber indicating film formation or carbon redeposition. Results show that dust deposition occurs first near the evacuation pumps due to the pressure gradient and then accumulates at the positively charged walls of the chamber. This method can be applied to monitor dust formation during dusty plasma experiments without major modification of plasma devices, useful especially for large fusion reactors.

  4. Vacuum chamber for containing particle beams

    DOE Patents [OSTI]

    Harvey, Alexander

    1987-01-01

    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.

  5. Vacuum chamber for containing particle beams

    DOE Patents [OSTI]

    Harvey, A.

    1985-11-26

    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.

  6. Right/left assignment in drift chambers and proportional multiwire chambers (PWC's) using induced signals

    DOE Patents [OSTI]

    Walenta, Albert H.

    1979-01-01

    Improved multiwire chamber having means for resolving the left/right ambiguity in the location of an ionizing event. The chamber includes a plurality of spaced parallel anode wires positioned between spaced planar cathodes. Associated with each of the anode wires are a pair of localizing wires, one positioned on either side of the anode wire. The localizing wires are connected to a differential amplifier whose output polarity is determined by whether the ionizing event occurs to the right or left of the anode wire.

  7. Vacuum chamber with a supersonic flow aerodynamic window

    DOE Patents [OSTI]

    Hanson, Clark L.

    1982-01-01

    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.

  8. Vacuum chamber with a supersonic-flow aerodynamic window

    DOE Patents [OSTI]

    Hanson, C.L.

    1980-10-14

    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.

  9. Development of bubble microstructure in ErT2 films during aging

    SciTech Connect (OSTI)

    Bond, Gillian; Snow, Clark

    2010-01-01

    Helium bubbles form in metal tritide films as tritium decays into 3He, influencing mechanical properties and long-term film stability. The bubble nucleation and growth mechanisms comprise an active research area, but there has been only one previous systematic experimental study of helium bubble growth in metal tritides, on zirconium tritides. There have been no such studies on tritides such as ErT2 that form plate-like bubbles and lack a secondary bubble population on a network of line dislocations, and yet such a study is needed to inform the modeling of helium-bubble microstructure development in a broader range of metal tritides. Transmission electron microscopy (TEM) has been used to study the growth and evolution of helium bubbles in ErT2 films over a four-year period. The results have been used to test the present models of helium bubble nucleation and growth in metal tritides, particularly those forming plate-like bubbles. The results support the models of Trinkaus and Cowgill. The observations of non-uniform bubble thicknesses and the pattern of grain-boundary bubble formation, however, indicate that these models could be strengthened by closer attention to details of interfacial energy. It is strongly recommended that efforts be made (either experimentally or by calculation) to determine anisotropy of tritide/helium interfacial energy, both for clean, stoichiometric interfaces, and also allowing for such factors as non-stoichiometry and segregation.

  10. Incorporation of Reaction Kinetics into a Multiphase, Hydrodynamic Model of a Fischer Tropsch Slurry Bubble Column Reactor

    SciTech Connect (OSTI)

    Donna Guillen, PhD; Anastasia Gribik; Daniel Ginosar, PhD; Steven P. Antal, PhD

    2008-11-01

    This paper describes the development of a computational multiphase fluid dynamics (CMFD) model of the Fischer Tropsch (FT) process in a Slurry Bubble Column Reactor (SBCR). The CMFD model is fundamentally based which allows it to be applied to different industrial processes and reactor geometries. The NPHASE CMFD solver [1] is used as the robust computational platform. Results from the CMFD model include gas distribution, species concentration profiles, and local temperatures within the SBCR. This type of model can provide valuable information for process design, operations and troubleshooting of FT plants. An ensemble-averaged, turbulent, multi-fluid solution algorithm for the multiphase, reacting flow with heat transfer was employed. Mechanistic models applicable to churn turbulent flow have been developed to provide a fundamentally based closure set for the equations. In this four-field model formulation, two of the fields are used to track the gas phase (i.e., small spherical and large slug/cap bubbles), and the other two fields are used for the liquid and catalyst particles. Reaction kinetics for a cobalt catalyst is based upon values reported in the published literature. An initial, reaction kinetics model has been developed and exercised to demonstrate viability of the overall solution scheme. The model will continue to be developed with improved physics added in stages.

  11. Study of electron trapping by a transversely ellipsoidal bubble in the laser wake-field acceleration

    SciTech Connect (OSTI)

    Cho, Myung-Hoon; Kim, Young-Kuk; Hur, Min Sup

    2013-09-15

    We present electron trapping in an ellipsoidal bubble which is not well explained by the spherical bubble model by [Kostyukov et al., Phys. Rev. Lett. 103, 175003 (2009)]. The formation of an ellipsoidal bubble, which is elongated transversely, frequently occurs when the spot size of the laser pulse is large compared to the plasma wavelength. First, we introduce the relation between the bubble size and the field slope inside the bubble in longitudinal and transverse directions. Then, we provide an ellipsoidal model of the bubble potential and investigate the electron trapping condition by numerical integration of the equations of motion. We found that the ellipsoidal model gives a significantly less restrictive trapping condition than that of the spherical bubble model. The trapping condition is compared with three-dimensional particle-in-cell simulations and the electron trajectory in test potential simulations.

  12. Bubble Density Dependent Functionals to Describe Deformation and Stress Equilibrium Evolution for In-Reactor Nuclear Fuel Materials

    SciTech Connect (OSTI)

    Stout, Ray B.

    2008-07-01

    Future designs of nuclear fuels require an increased understanding of fission gas bubble density evolution. Derivations will be provided for a generic Boltzmann bubble density evolution equation, a bubble density deformation field equation, and a Cauchy stress/bubble-pressure equilibrium equation. (author)

  13. Analysis of the three-dimensional structure of a bubble wake using PIV and Galilean decomposition

    SciTech Connect (OSTI)

    Hassan, Y.A.; Schmidl, W.D.; Ortiz-Villafuerte, J.; Scharf, J.R.

    1999-07-01

    Bubbly flow plays a key role in a variety of natural and industrial processes. An accurate and complete description of the phase interactions in two-phase bubbly flow is not available at this time. These phase interactions are, in general, always three-dimensional and unsteady. Therefore, measurement techniques utilized to obtain qualitative and quantitative data from two-phase flow should be able to acquire transient and three-dimensional data, in order to provide information to test theoretical models and numerical simulations. Even for dilute bubble flows, in which bubble interaction is at a minimum, the turbulent motion of the liquid generated by the bubble is yet to be completely understood. For many years, the design of systems with bubbly flows was based primarily on empiricism. Dilute bubbly flows are an extension of single bubble dynamics, and therefore improvements in the description and modeling of single bubble motion, the flow field around the bubble, and the dynamical interactions between the bubble and the flow will consequently improve bubbly flow modeling. The improved understanding of the physical phenomena will have far-reaching benefits in upgrading the operation and efficiency of current processes and in supporting the development of new and innovative approaches. A stereoscopic particle image velocimetry measurement of the flow generated by the passage of a single air-bubble rising in stagnant water, in a circular pipe is presented. Three-dimensional velocity fields within the measurement zone were obtained. Ensemble-averaged instantaneous velocities for a specific bubble path were calculated and interpolated to obtain mean three-dimensional velocity fields. A Galilean velocity decomposition is used to study the vorticity generated in the flow.

  14. Wire chamber radiation detector with discharge control

    DOE Patents [OSTI]

    Perez-Mendez, Victor; Mulera, Terrence A.

    1984-01-01

    A wire chamber radiation detector (11) has spaced apart parallel electrodes (16) and grids (17, 18, 19) defining an ignition region (21) in which charged particles (12) or other ionizing radiations initiate brief localized avalanche discharges (93) and defining an adjacent memory region (22) in which sustained glow discharges (94) are initiated by the primary discharges (93). Conductors (29, 32) of the grids (18, 19) at each side of the memory section (22) extend in orthogonal directions enabling readout of the X-Y coordinates of locations at which charged particles (12) were detected by sequentially transmitting pulses to the conductors (29) of one grid (18) while detecting transmissions of the pulses to the orthogonal conductors (36) of the other grid (19) through glow discharges (94). One of the grids (19) bounding the memory region (22) is defined by an array of conductive elements (32) each of which is connected to the associated readout conductor (36) through a separate resistance (37). The wire chamber (11) avoids ambiguities and imprecisions in the readout of coordinates when large numbers of simultaneous or near simultaneous charged particles (12) have been detected. Down time between detection periods and the generation of radio frequency noise are also reduced.

  15. Integrated Management Tracking System

    Energy Science and Technology Software Center (OSTI)

    2000-03-30

    The Integrated Management Tracking System (IMTS) is a "Web Enabled" Client/Server Business application that provides for the Identification and Resolution of commitments, situations, events and problems. The IMTS engine is written with Microsoft Active Server Pages (ASP) for IIS4. The system provides for reporting, entering, editing, closing and administration over a Intranet, Extranet or Internet. This Application facilitates: Electronic assignment, acceptance and tracking to completion. Email notifications of assigned action. Establishment of Due Dates. Electronicmore » search and retrieval based on keywords in combination with user specified database parameters (Document Type, Date Ranges, etc.). Coded for Trending and Reporting. User selected reports. Various levels of access for reports and administration. The "Server" side of this application consists of a Microsoft Access database running on a NT Server with Internet Information Server (IIS). As the "Client" side of the application runs on any Web browser, this solution is a cost effective, user friendly application that lends itself to organizations not physically colocated in one location providing information immediately available to everyone at once.« less

  16. Engineering Development of Slurry Bubble Column Reactor (SBCR) Technology

    SciTech Connect (OSTI)

    Toseland, B.A.

    1998-10-29

    The major technical objectives of this program are threefold: (1) to develop the design tools and a fundamental understanding of the fluid dynamics of a slurry bubble column reactor to maximize reactor productivity, (2) to develop the mathematical reactor design models and gain an understanding of the hydrodynamic fundamentals under industrially relevant process conditions, and (3) to develop an understanding of the hydrodynamics and their interaction with the chemistries occurring in the bubble column reactor. Successful completion of these objectives will permit more efficient usage of the reactor column and tighter design criteria, increase overall reactor efficiency, and ensure a design that leads to stable reactor behavior when scaling up to large diameter reactors.

  17. REC Tracking Systems Design Guide

    SciTech Connect (OSTI)

    Meredith Wingate

    2004-02-03

    OAK-B135 The Design Guide is presented in three parts. Section II describes the need for REC tracking, the two principal tracking methods available, and, in simple terms, the operation of certificate-based systems. Section III presents the major issues in the design of certificate-based tracking systems and discusses the advantages and disadvantages of alternative solutions. Finally, Section IV offers design principles or recommendations for most of these issues.

  18. Stationary bubbles and their tunneling channels toward trivial geometry

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

    Chen, Pisin; Domènech, Guillem; Sasaki, Misao; Yeom, Dong-han

    2016-04-07

    In the path integral approach, one has to sum over all histories that start from the same initial condition in order to obtain the final condition as a superposition of histories. Applying this into black hole dynamics, we consider stable and unstable stationary bubbles as a reasonable and regular initial condition. We find examples where the bubble can either form a black hole or tunnel toward a trivial geometry, i.e., with no singularity nor event horizon. We investigate the dynamics and tunneling channels of true vacuum bubbles for various tensions. In particular, in line with the idea of superposition ofmore » geometries, we build a classically stable stationary thin-shell solution in a Minkowski background where its fate is probabilistically given by non-perturbative effects. Since there exists a tunneling channel toward a trivial geometry in the entire path integral, the entire information is encoded in the wave function. This demonstrates that the unitarity is preserved and there is no loss of information when viewed from the entire wave function of the universe, whereas a semi-classical observer, who can see only a definitive geometry, would find an effective loss of information. Ultimately, this may provide a resolution to the information loss dilemma.« less

  19. Helium bubble linkage and the transition to rapid He release in aging Pd tritide.

    SciTech Connect (OSTI)

    Cowgill, Donald F.

    2006-02-01

    A model is presented for the linking of helium bubbles growing in aging metal tritides. Stresses created by neighboring bubbles are found to produce bubble growth toward coalescence. This process is interrupted by the fracture of ligaments between bubble arrays. The condition for ligament fracture percolates through the material to reach external surfaces, leading to material micro-cracking and the release of helium within the linked-bubble cluster. A comparison of pure coalescence and pure fracture mechanisms shows the critical HeM concentration for bubble linkage is not strongly dependent on details of the linkage process. The combined stress-directed growth and fracture process produces predictions for the onset of rapid He release and the He emission rate. Transition to this rapid release state is determined from the physical size of the linked-bubble clusters, which is calculated from dimensional invariants in classical percolation theory. The result is a transition that depends on material dimensions. The onset of bubble linkage and rapid He release are found to be quite sensitive to the bubble spacing distribution, which is log-normal for bubbles nucleated by self-trapping.

  20. Solar Array Tracking Control

    Energy Science and Technology Software Center (OSTI)

    1995-06-22

    SolarTrak used in conjunction with various versions of 68HC11-based SolarTrack hardware boards provides control system for one or two axis solar tracking arrays. Sun position is computed from stored position data and time from an on-board clock/calendar chip. Position feedback can be by one or two offset motor turn counter square wave signals per axis, or by a position potentiometer. A limit of 256 counts resolution is imposed by the on-board analog to digital (A/D)more » convertor. Control is provided for one or two motors. Numerous options are provided to customize the controller for specific applications. Some options are imposed at compile time, some are setable during operation. Software and hardware board designs are provided for Control Board and separate User Interface Board that accesses and displays variables from Control Board. Controller can be used with range of sensor options ranging from a single turn count sensor per motor to systems using dual turn-count sensors, limit sensors, and a zero reference sensor. Dual axis trackers oriented azimuth elevation, east west, north south, or polar declination can be controlled. Misalignments from these orientations can also be accommodated. The software performs a coordinate transformation using six parameters to compute sun position in misaligned coordinates of the tracker. Parameters account for tilt of tracker in two directions, rotation about each axis, and gear ration errors in each axis. The software can even measure and compute these prameters during an initial setup period if current from a sun position sensor or output from photovoltaic array is available as an anlog voltage to the control board''s A/D port. Wind or emergency stow to aj present position is available triggered by digital or analog signals. Night stow is also available. Tracking dead band is adjustable from narrow to wide. Numerous features of the hardware and software conserve energy for use with battery powered systems.« less

  1. Quantum combustion chamber for the digital engine

    SciTech Connect (OSTI)

    Evers, L.W.; Baasch, V.

    1985-01-01

    For increasing fuel economy and reducing hydrocarbon emissions, a two-stoke-cycle, loop-scavenged single cylinder engine was modified by replacing the head with a head having three subchambers and incorporating a distributing pump fuel injection system. The fuel injection system allowed one subchamber to be operated at a time. The quantum combustion system demonstrated both lower fuel consumption and lower hydrocarbon emissions than a conventional homogeneous charge engine. The experimental evidence also indicates that the combustion essentially occurred in the one chamber into which fuel was injected. Establishing stratified charge combustion by mechanically separating the regions of air from the regions of air/fuel mixtures by means of subchambers is feasible.

  2. Intrinsic Feature Motion Tracking

    Energy Science and Technology Software Center (OSTI)

    2013-03-19

    Subject motion during 3D medical scanning can cause blurring and artifacts in the 3D images resulting in either rescans or poor diagnosis. Anesthesia or physical restraints may be used to eliminate motion but are undesirable and can affect results. This software measures the six degree of freedom 3D motion of the subject during the scan under a rigidity assumption using only the intrinsic features present on the subject area being monitored. This movement over timemore » can then be used to correct the scan data removing the blur and artifacts. The software acquires images from external cameras or images stored on disk for processing. The images are from two or three calibrated cameras in a stereo arrangement. Algorithms extract and track the features over time and calculate position and orientation changes relative to an initial position. Output is the 3D position and orientation change measured at each image.« less

  3. Jo Sexton, President, Cambridge Area Chamber of Commerce Panel...

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

    Outliine for QER July 21, 2014 Jo Sexton, President, Cambridge Area Chamber of Commerce Panel 3 Public-Private Partnerships for Economic Growth and Workforce Development How a ...

  4. Saku Chamber of Commers Indsutry | Open Energy Information

    Open Energy Info (EERE)

    Jump to: navigation, search Name: Saku Chamber of Commers&Indsutry Place: Saku, Nagano, Japan Zip: 3850051 Product: An organization engages in improving the collaboration and...

  5. Chambers County, Alabama: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Chambers County, Alabama: Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates 32.9028048, -85.354965 Show Map Loading map... "minzoom":false,"mappi...

  6. Chambers County, Texas: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    County, Texas Reliant Baytown Biomass Facility Places in Chambers County, Texas Anahuac, Texas Baytown, Texas Beach City, Texas Cove, Texas Mont Belvieu, Texas Old...

  7. Chamber of Commerce Recognizes Portsmouth Site Specific Advisory Board

    Broader source: Energy.gov [DOE]

    PIKETON, Ohio – The Pike County Chamber of Commerce recently recognized the Portsmouth Site Specific Advisory Board (SSAB) as its 2015 Organization of the Year.

  8. PHASE-FIELD SIMULATION OF INTERGRANULAR BUBBLE GROWTH AND PERCOLATION IN BICRYSTALS

    SciTech Connect (OSTI)

    Paul C. Millett; Michael Tonks; S. B. Biner; Liangzhe Zhang; K. Chockalingam; Yongfeng Zhang

    2012-06-01

    We present three-dimensional phase-field simulations of the growth and coalescence of intergranular bubbles in bicrystal grain geometries. We investigate the dependency of bubble percolation on two factors: the initial bubble density and the bubble shape, which is governed by the ratio of the grain boundary energy over the surface energy. We find that variations of each of these factors can lead to large discrepancies in the bubble coalescence rate, and eventual percolation, which may partially explain this observed occurrence in experimental investigations. The results presented here do not account for concurrent gas production and bubble resolution due to irradiation, therefore this simulation study is most applicable to post-irradiation annealing.

  9. Electrons trajectories around a bubble regime in intense laser plasma interaction

    SciTech Connect (OSTI)

    Lu, Ding; Xie, Bai-Song; Ali Bake, Muhammad; Sang, Hai-Bo; Zhao, Xue-Yan; Wu, Hai-Cheng

    2013-06-15

    Some typical electrons trajectories around a bubble regime in intense laser plasma interaction are investigated theoretically. By considering a modification of the fields and ellipsoid bubble shape due to the presence of residual electrons in the bubble regime, we study in detail the electrons nonlinear dynamics with or without laser pulse. To examine the electron dynamical behaviors, a set of typical electrons, which locate initially at the front of the bubble, on the transverse edge and at the bottom of the bubble respectively, are chosen for study. It is found that the range of trapped electrons in the case with laser pulse is a little narrower than that without laser pulse. The partial phase portraits for electrons around the bubble are presented numerically and their characteristic behaviors are discussed theoretically. Implication of our results on the high quality electron beam generation is also discussed briefly.

  10. SRNL Tagging and Tracking Video

    ScienceCinema (OSTI)

    None

    2016-06-15

    SRNL generates a next generation satellite base tracking system. The tagging and tracking system can work in remote wilderness areas, inside buildings, underground and other areas not well served by traditional GPS. It?s a perfect response to customer needs and market demand.

  11. BIA Providers Conference Energy Track

    Broader source: Energy.gov [DOE]

    The U.S. Department of Energy (DOE) Office of Indian Energy is offering an energy track at the 25th Annual BIA Tribal Providers Conference Dec. 2-3, 2015. The track will feature breakout sessions on a variety of topics to help tribal energy leaders and professionals make informed decisions about energy projects.

  12. Ultrasonic effect on the bubble nucleation and heat transfer of oscillating nanofluid

    SciTech Connect (OSTI)

    Zhao, Nannan; Fu, Benwei; Ma, H. B.

    2014-06-30

    Ultrasonic sound effect on bubble nucleation, oscillating motion activated by bubble formation, and its heat transfer enhancement of nanofluid was experimentally investigated. Nanofluid consists of distilled water and dysprosium (III) oxide (Dy{sub 2}O{sub 3}) nanoparticles with an average size of 98?nm and a mass ratio of 0.5%. Visualization results demonstrate that when the nanoparticles are added in the fluid influenced by the ultrasonic sound, bubble nucleation can be significantly enhanced. The oscillating motion initiated by the bubble formation of nanofluid under the influence of ultrasonic sound can significantly enhance heat transfer of nanofluid in an interconnected capillary loop.

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

    Office of Scientific and Technical Information (OSTI)

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

  14. Fluorescent image tracking velocimeter

    DOE Patents [OSTI]

    Shaffer, Franklin D.

    1994-01-01

    A multiple-exposure fluorescent image tracking velocimeter (FITV) detects and measures the motion (trajectory, direction and velocity) of small particles close to light scattering surfaces. The small particles may follow the motion of a carrier medium such as a liquid, gas or multi-phase mixture, allowing the motion of the carrier medium to be observed, measured and recorded. The main components of the FITV include: (1) fluorescent particles; (2) a pulsed fluorescent excitation laser source; (3) an imaging camera; and (4) an image analyzer. FITV uses fluorescing particles excited by visible laser light to enhance particle image detectability near light scattering surfaces. The excitation laser light is filtered out before reaching the imaging camera allowing the fluoresced wavelengths emitted by the particles to be detected and recorded by the camera. FITV employs multiple exposures of a single camera image by pulsing the excitation laser light for producing a series of images of each particle along its trajectory. The time-lapsed image may be used to determine trajectory and velocity and the exposures may be coded to derive directional information.

  15. Paint coatings: Controlled field and chamber experiments

    SciTech Connect (OSTI)

    Edney, E.O.

    1989-04-01

    To determine the impact of pollution levels on the weathering rates of coatings, laboratory chamber experiments and controlled field exposures at North Carolina and Ohio sites were conducted in such a manner to separate the contributions due to dry deposition, wet deposition, precipitation pH, etc. The results of these studies confirm that acidic gases such as SO/sub 2/ and HNO/sub 3/, as well as acids within rain, promote the dissolution of alkaline components including CaCO/sub 3/, ZnO, and Al flake from paint films. It is unclear from these studies whether the removal of these components reduces the service life or protective properties of the paint film. Other researchers within the Coatings Effects Program are conducting subsequent analyses to determine micro-damage of these paints. The uptake of acidic gases to painted surfaces is a complex process that depends on several factors. The deposition rate of SO/sub 2/ to a wet, painted surface may be controlled by the level of oxidants such as H/sub 2/O/sub 2/.

  16. Vacuum chamber for ion manipulation device

    DOE Patents [OSTI]

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

    2014-12-09

    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.

  17. PIA - Security Clearance Tracking System | Department of Energy

    Office of Environmental Management (EM)

    Tracking System PIA - Security Clearance Tracking System PIA - Security Clearance Tracking System PIA - Security Clearance Tracking System (209.32 KB) More Documents & Publications ...

  18. Fast Magnetic Reconnection in Laser-Produced Plasma Bubbles

    SciTech Connect (OSTI)

    Fox, W.; Bhattacharjee, A.; Germaschewski, K.

    2011-05-27

    Recent experiments have observed magnetic reconnection in high-energy-density, laser-produced plasma bubbles, with reconnection rates observed to be much higher than can be explained by classical theory. Based on fully kinetic particle simulations we find that fast reconnection in these strongly driven systems can be explained by magnetic flux pileup at the shoulder of the current sheet and subsequent fast reconnection via two-fluid, collisionless mechanisms. In the strong drive regime with two-fluid effects, we find that the ultimate reconnection time is insensitive to the nominal system Alfven time.

  19. Abrasion resistant track shoe grouser

    DOE Patents [OSTI]

    Fischer, Keith D; Diekevers, Mark S; Afdahl, Curt D; Steiner, Kevin L; Barnes, Christopher A

    2013-04-23

    A track shoe for a track-type vehicle. The track shoe includes a base plate and a grouser projecting away from the base plate. A capping surface structure of substantially horseshoe shaped cross-section is disposed across a distal portion of the grouser. The capping surface structure covers portions of a distal edge surface and adjacent lateral surfaces. The capping surface structure is formed from an material characterized by enhanced wear resistance relative to portions of the grouser underlying the capping surface structure.

  20. High resolution track etch autoradiography

    DOE Patents [OSTI]

    Solares, G.; Zamenhof, R.G.

    1994-12-27

    A detector assembly is disclosed for use in obtaining alpha-track autoradiographs, the detector assembly including a substantially boron-free substrate; a detector layer deposited on the substantially boron-free substrate, the detector layer being capable of recording alpha particle tracks and exhibiting evidence of the alpha tracks in response to being exposed to an etchant, the detector layer being less than about 2 microns thick; and a protective layer deposited on the detector layer, the protective layer being resistant to the etchant and having a thickness of about 0.5 to 1 microns. 13 figures.

  1. High resolution track etch autoradiography

    DOE Patents [OSTI]

    Solares, Guido (Arlington, MA); Zamenhof, Robert G. (Brookline, MA)

    1994-01-01

    A detector assembly for use in obtaining alpha-track autoradiographs, the detector assembly including a substantially boron-free substrate; a detector layer deposited on the substantially boron-free substrate, the detector layer being capable of recording alpha particle tracks and exhibiting evidence of the alpha tracks in response to being exposed to an etchant, the detector layer being less than about 2 microns thick; and a protective layer deposited on the detector layer, the protective layer being resistant to the etchant and having a thickness of about 0.5 to 1 microns.

  2. Tracking Individual Gold Nanoparticles | The Ames Laboratory

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

    Tracking Individual Gold Nanoparticles Researchers have developed a new way to track gold nanorods as they move around and re-orient themselves on metal surfaces, with ...

  3. FFTF Asbestos Location Tracking Program

    SciTech Connect (OSTI)

    Reynolds, J.A.

    1994-09-15

    An Asbestos Location Tracking Program was prepared to list, locate, and determine Asbestos content and to provide baseline {open_quotes}good faith{close_quotes} for yearly condition inspections for the FFTF Plant and buildings and grounds.

  4. Generation and characterization of gas bubbles in liquid metals

    SciTech Connect (OSTI)

    Eckert, S.; Gerbeth, G.; Witke, W.

    1996-06-01

    There is an ongoing research performed in the RCR on local transport phenomena in turbulent liquid metal (LM) duct flows exposed to external magnetic fields. In this context so-called MHD flow phenomena can be observed, which are unknown in usual hydraulic engineering. The field of interest covers also the influence of magnetic fields on the behaviour of liquid metal - gas mixtures. Profound knowledge on these LMMHD two-phase flow plays an important role in a variety of technological applications, in particular, in the design of Liquid-Metal MHD generators or for several metallurgical processes employing gas-stirred reactors. However, the highly empirical nature of two-phase flow analysis gives little hope for the prediction of MHD two-phase flows without extensive experimental data. A summary is given about the authors research activities focussing on two directions: (a) Momentum transfer between gas and liquid metal in a bubbly flow regime to investigate the influence of the external magnetic field on the velocity slip ration S (b) Peculiarities of the MHD turbulence to use small gas bubbles as local tracers in order to study the turbulent mass transfer.

  5. Mechanisms of self-excitation of thermoacoustic vibrations in two-phase bubble flows

    SciTech Connect (OSTI)

    Skalozubov, V.I. )

    1991-01-01

    In this paper, the mechanisms of self-excitation of thermoacoustic vibrations in two-phase bubble flows are described. It is shown that a theory of this process must take into consideration the work performed by bubbles traveling in the acoustic wave. The results of the theory herein developed agree with previous experimental data of the author.

  6. Turbine component cooling channel mesh with intersection chambers

    DOE Patents [OSTI]

    Lee, Ching-Pang; Marra, John J

    2014-05-06

    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).

  7. Application of Phase-field Method in Predicting Gas Bubble Microstructure Evolution in Nuclear Fuels

    SciTech Connect (OSTI)

    Hu, Shenyang Y.; Li, Yulan; Sun, Xin; Gao, Fei; Devanathan, Ramaswami; Henager, Charles H.; Khaleel, Mohammad A.

    2010-04-30

    Fission product accumulation and gas bubble microstructure evolution in nuclear fuels strongly affect thermo-mechanical properties such as thermal conductivity, gas release, volumetric swelling and cracking, and hence the fuel performance. In this paper, a general phase-field model is developed to predict gas bubble formation and evolution. Important materials processes and thermodynamic properties including the generation of gas atoms and vacancies, sinks for vacancies and gas atoms, the elastic interaction among defects, gas re-solution, and inhomogeneity of elasticity and diffusivity are accounted for in the model. The simulations demonstrate the potential application of the phase-field method in investigating 1) heterogeneous nucleation of gas bubbles at defects; 2) effect of elastic interaction, inhomogeneity of material properties, and gas re-solution on gas bubble microstructures; and 3) effective properties from the output of phase-field simulations such as distribution of defects, gas bubbles, and stress fields.

  8. Computer program for the sensitivity calculation of a CR-39 detector in a diffusion chamber for radon measurements

    SciTech Connect (OSTI)

    Nikezic, D. Stajic, J. M.; Yu, K. N.

    2014-02-15

    Computer software for calculation of the sensitivity of a CR-39 detector closed in a diffusion chamber to radon is described in this work. The software consists of two programs, both written in the standard Fortran 90 programming language. The physical background and a numerical example are given. Presented software is intended for numerous researches in radon measurement community. Previously published computer programs TRACK-TEST.F90 and TRACK-VISION.F90 [D. Nikezic and K. N. Yu, Comput. Phys. Commun. 174, 160 (2006); D. Nikezic and K. N. Yu, Comput. Phys. Commun. 178, 591 (2008)] are used here as subroutines to calculate the track parameters and to determine whether the track is visible or not, based on the incident angle, impact energy, etching conditions, gray level, and visibility criterion. The results obtained by the software, using five different V functions, were compared with the experimental data found in the literature. Application of two functions in this software reproduced experimental data very well, while other three gave lower sensitivity than experiment.

  9. Environmental chamber studies of atmospheric reactivities of volatile organic compounds: Effects of varying chamber and light source

    SciTech Connect (OSTI)

    Carter, W.; Luo, D.; Malkina, I.; Pierce, J.

    1995-05-01

    Photochemical oxidant models are essential tools for assessing effects of emissions changes on ground-level ozone formation. Such models are needed for predicting the ozone impacts of increased alternative fuel use. The gas-phase photochemical mechanism is an important component of these models because ozone is not emitted directly, but is formed from the gas-phase photochemical reactions of the emitted volatile organic compounds (VOCs) and oxides of nitrogen (NO{sub x}) in air. The chemistry of ground level ozone formation is complex; hundreds of types of VOCs being emitted into the atmosphere, and most of their atmospheric reactions are not completely understood. Because of this, no chemical model can be relied upon to give even approximately accurate predictions unless it has been evaluated by comparing its predictions with experimental data. Therefore an experimental and modeling study was conducted to assess how chemical mechanism evaluations using environmental chamber data are affected by the light source and other chamber characteristics. Xenon arc lights appear to give the best artificial representation of sunlight currently available, and experiments were conducted in a new Teflon chamber constructed using such a light source. Experiments were also conducted in an outdoor Teflon Chamber using new procedures to improve the light characterization, and in Teflon chambers using blacklights. These results, and results of previous runs other chambers, were compared with model predictions using an updated detailed chemical mechanism. The magnitude of the chamber radical source assumed when modeling the previous runs were found to be too high; this has implications in previous mechanism evaluations. Temperature dependencies of chamber effects can explain temperature dependencies in chamber experiments when Ta-300{degree}K, but not at temperatures below that.

  10. Track 4: Employee Health and Wellness

    Office of Energy Efficiency and Renewable Energy (EERE)

    ISM Workshop Presentations Knoxville Convention Center, Knoxville, TN August 2009 Track 4: Employee Health and Wellness

  11. Performance of a Drift Chamber Candidate for a Cosmic Muon Tomography System

    SciTech Connect (OSTI)

    Anghel, V.; Jewett, C.; Jonkmans, G.; Thompson, M.; Armitage, J.; Botte, J.; Boudjemline, K.; Erlandson, A.; Oakham, G.; Bueno, J.; Bryman, D.; Liu, Z.; Charles, E.; Gallant, G.; Cousins, T.; Noel, S.; Drouin, P.-L.; Waller, D.; Stocki, T. J.

    2011-12-13

    In the last decade, many groups around the world have been exploring different ways to probe transport containers which may contain illicit Special Nuclear Materials such as uranium. The muon tomography technique has been proposed as a cost effective system with an acceptable accuracy. A group of Canadian institutions (see above), funded by Defence Research and Development Canada, is testing different technologies to track the cosmic muons. One candidate is the single wire Drift Chamber. With the capability of a 2D impact position measurement, two detectors will be placed above and two below the object to be probed. In order to achieve a good 3D image quality of the cargo content, a good angular resolution is required. The simulation showed that 1mrad was required implying the spatial resolution of the trackers must be in the range of 1 to 2 mm for 1 m separation. A tracking system using three prototypes has been built and tested. The spatial resolution obtained is 1.7 mm perpendicular to the wire and 3 mm along the wire.

  12. DEVELOPMENT OF TITANIUM NITRIDE COATING FOR SNS RING VACUUM CHAMBERS.

    SciTech Connect (OSTI)

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

    2001-06-18

    The inner surface of the ring vacuum chambers of the US Spallation Neutron Source (SNS) will be coated with {approximately}100 nm of Titanium Nitride (TiN). This is to minimize the secondary electron yield (SEY) from the chamber wall, and thus avoid the so-called e-p instability caused by electron multipacting as observed in a few high-intensity proton storage rings. Both DC sputtering and DC-magnetron sputtering were conducted in a test chamber of relevant geometry to SNS ring vacuum chambers. Auger Electron Spectroscopy (AES) and Rutherford Back Scattering (RBS) were used to analyze the coatings for thickness, stoichiometry and impurity. Excellent results were obtained with magnetron sputtering. The development of the parameters for the coating process and the surface analysis results are presented.

  13. Ducted combustion chamber for direct injection engines and method

    DOE Patents [OSTI]

    Mueller, Charles

    2015-03-03

    An internal combustion engine includes an engine block having a cylinder bore and a cylinder head having a flame deck surface disposed at one end of the cylinder bore. A piston connected to a rotatable crankshaft and configured to reciprocate within the cylinder bore has a piston crown portion facing the flame deck surface such that a combustion chamber is defined within the cylinder bore and between the piston crown and the flame deck surface. A fuel injector having a nozzle tip disposed in fluid communication with the combustion chamber has at least one nozzle opening configured to inject a fuel jet into the combustion chamber along a fuel jet centerline. At least one duct defined in the combustion chamber between the piston crown and the flame deck surface has a generally rectangular cross section and extends in a radial direction relative to the cylinder bore substantially along the fuel jet centerline.

  14. Effects of outgassing of loader chamber walls on hydriding of...

    Office of Scientific and Technical Information (OSTI)

    gas pressure. Complete process data for (1) a copper-(1.83 wt. %)beryllium wet hydrogen fired passivated (600 C-1 h) externally heated pipe hydriding chamber are reported....

  15. MHK Technologies/Multi Resonant Chambers MRC 1000 | Open Energy...

    Open Energy Info (EERE)

    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...

  16. Gas Electron Multiplier (GEM) Chamber Characteristics Test (Technical...

    Office of Scientific and Technical Information (OSTI)

    x 30cm chamber integrated with the SLAC-developed 64 channel kPiX analog readout chip. ... 1cm x 1cm pad granularity with 64 channel 2-D simultaneous readout using the kPiX chip. ...

  17. Carrying Semiautomatic Pistols with a Round in the Chamber

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

    1999-10-28

    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.

  18. Santa Fe Chamber of Commerce Business Awards Gala

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

    Santa Fe Chamber of Commerce Business Awards Gala Santa Fe Chamber of Commerce Business Awards Gala WHEN: Jun 04, 2015 5:30 PM - 7:30 PM WHERE: Skylight 139 West San Francisco Street, Santa Fe CATEGORY: Community INTERNAL: Calendar Login Event Description An event to recognize some of Santa Fe's best and brightest businesses in the following categories: Business Excellence, Small Business of the Year, Family Friendly Business, Green Business, and Woman Owned Business. Come dressed to impress for

  19. OSTIblog Articles in the Tennessee Chamber of Commerce and Industry Topic |

    Office of Scientific and Technical Information (OSTI)

    OSTI, US Dept of Energy Office of Scientific and Technical Information Tennessee Chamber of Commerce and Industry Topic TENNESSEE CHAMBER OF COMMERCE & INDUSTRY LAUDS OSTI by Kate Bannan 30 Jun, 2011 in Science Communications 4367 header_chamber.gif TENNESSEE CHAMBER OF COMMERCE & INDUSTRY LAUDS OSTI Read more about 4367 We are proud to note that OSTI was featured in the Tennessee Chamber of Commerce & Industry'ssummer issue of its newsletter, the Business Insider. The Chamber

  20. Lifetime survivability of contaminated target-chamber optics

    SciTech Connect (OSTI)

    Rainer, F.; Anderson, A.; Burnham, A.; Milam, D.; Turner, R.

    1996-11-01

    Target chambers used for Inertial Confinement Fusion (ICF) expose laser optics to a very hostile environment, not only from high-fluence laser irradiation but also x-ray irradiation and particulate debris from targets and chamber wall materials. Expendable debris shields provide the first line of defense to more costly optics upstream in the laser beam path to contaminants generated within the target chamber. However, the replacement of a large number of debris shields is also an expensive proposition so that extending their usable lifetime within the chamber is important. We have conducted tests to show that optics can both be cleaned and damaged by laser irradiation at 355 nm after being contaminated with potential chamber-wall materials such as B{sub 4}C and Al{sub 2}O{sub 3}. Such optics can survive from one to hundreds of laser shots, depending on degree of contamination and laser fluence levels. Similarly, we have studied the survivability of optics that have been exposed to direct contamination from representative target materials irradiated in the target chamber. We have also studied the effects on optics that were not directly exposed to targets, yet received secondary exposure from the above directly-exposed samples.

  1. Heavy oil upgrading using halide catalysts in a bubbling microautoclave

    SciTech Connect (OSTI)

    Chakma, A.; Chornet, E.; Overend, R.P.; Dawson, W. )

    1988-01-01

    Athabasca bitumen has been treated with halide catalysts under a continuous flow of H{sub 2} in a 15 ml microautoclave. The H{sub 2} was bubbled through the liquid using a microporous steel grid. ZnCl{sub 2}, CuCl and ZnCl{sub 2}/CuCl mixtures, with and without tetralin, were used as catalysts. The experimental conditions were: 13.8 MPa operating pressure, 1 liter STP/min as H{sub 2} flow rate, 425-450 C and 30 min as reaction temperature and time, respectively. ZnCl{sub 2} has been found effective for converting asphaltenes into maltenes while lowering the coke formation with respect to the uncatalyzed reaction. The addition of tetralin to the reaction mixture minimized coke and gas formation.

  2. Heavy oil upgrading using halide catalysts in a bubbling microautoclave

    SciTech Connect (OSTI)

    Chakma, A.; Chornet, E.; Overend, R.P. ); Dawson, W. )

    1988-06-01

    Athabasca bitumen with halide catalysts has been treated under a continuous flow of H/sub 2/ in a 15 mL microautoclave. The H/sub 2/ was bubbled through the liquid using a microporous steel grid. ZnCl/sub 2/, CuCl and ZnCl/sub 2//CuCl mixtures, with and without tetralin, were used as catalysts. The experimental conditions were: 13.8 MPa operating pressure, 1 L/sub STP/min/ as H/sub 2/ flowrate, 425 - 450/sup 0/C and 30 min as reaction temperature and time respectively. ZnCl/sub 2/ has been found effective for converting asphaltenes into maltenes while lowering the coke formation with respect to the uncatalyzed reaction. The addition of tetralin to the reaction mixture minimized coke and gas formation.

  3. The Majorana Parts Tracking Database

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

    Abgrall, N.

    2015-01-16

    The Majorana Demonstrator is an ultra-low background physics experiment searching for the neutrinoless double beta decay of 76Ge. The Majorana Parts Tracking Database is used to record the history of components used in the construction of the Demonstrator. The tracking implementation takes a novel approach based on the schema-free database technology CouchDB. Transportation, storage, and processes undergone by parts such as machining or cleaning are linked to part records. Tracking parts provides a great logistics benefit and an important quality assurance reference during construction. In addition, the location history of parts provides an estimate of their exposure to cosmic radiation.more » In summary, a web application for data entry and a radiation exposure calculator have been developed as tools for achieving the extreme radio-purity required for this rare decay search.« less

  4. The Majorana Parts Tracking Database

    SciTech Connect (OSTI)

    Abgrall, N.

    2015-01-16

    The Majorana Demonstrator is an ultra-low background physics experiment searching for the neutrinoless double beta decay of 76Ge. The Majorana Parts Tracking Database is used to record the history of components used in the construction of the Demonstrator. The tracking implementation takes a novel approach based on the schema-free database technology CouchDB. Transportation, storage, and processes undergone by parts such as machining or cleaning are linked to part records. Tracking parts provides a great logistics benefit and an important quality assurance reference during construction. In addition, the location history of parts provides an estimate of their exposure to cosmic radiation. In summary, a web application for data entry and a radiation exposure calculator have been developed as tools for achieving the extreme radio-purity required for this rare decay search.

  5. Modeling the impediment of methane ebullition bubbles by seasonal lake ice

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

    Greene, S.; Walter Anthony, K. M.; Archer, D.; Sepulveda-Jauregui, A.; Martinez-Cruz, K.

    2014-07-15

    Microbial methane (CH4) ebullition (bubbling) from anoxic lake sediments comprises a globally significant flux to the atmosphere, but ebullition bubbles in temperate and polar lakes can be trapped by winter ice cover and later released during spring thaw. This "ice-bubble storage" (IBS) constitutes a novel mode of CH4 emission. Before bubbles are encapsulated by downward-growing ice, some of their CH4 dissolves into the lake water, where it may be subject to oxidation. We present field characterization and a model of the annual CH4 cycle in Goldstream Lake, a thermokarst (thaw) lake in interior Alaska. We find that summertime ebullition dominatesmore » annual CH4 emissions to the atmosphere. Eighty percent of CH4 in bubbles trapped by ice dissolves into the lake water column in winter, and about half of that is oxidized. The ice growth rate and the magnitude of the CH4 ebullition flux are important controlling factors of bubble dissolution. Seven percent of annual ebullition CH4 is trapped as IBS and later emitted as ice melts. In a future warmer climate, there will likely be less seasonal ice cover, less IBS, less CH4 dissolution from trapped bubbles, and greater CH4 emissions from northern lakes.« less

  6. Gas-bubble growth mechanisms in the analysis of metal fuel swelling

    SciTech Connect (OSTI)

    Gruber, E.E.; Kramer, J.M.

    1986-06-01

    During steady-state irradiation, swelling rates associated with growth of fission-gas bubbles in metallic fast reactor fuels may be expected to remain small. As a consequence, bubble-growth mechanisms are not a major consideration in modeling the steady-state fuel behavior, and it is usually adequate to consider the gas pressure to be in equilibrium with the external pressure and surface tension restraint. On transient time scales, however, various bubble-growth mechanisms become important components of the swelling rate. These mechanisms include growth by diffusion, for bubbles within grains and on grain boundaries; dislocation nucleation at the bubble surface, or ''punchout''; and bubble growth by creep. Analyses of these mechanisms are presented and applied to provide information on the conditions and the relative time scales for which the various processes should dominate fuel swelling. The results are compared to a series of experiments in which the swelling of irradiated metal fuel was determined after annealing at various temperatures and pressures. The diffusive growth of bubbles on grain boundaries is concluded to be dominant in these experiments.

  7. COMPUTATIONAL AND EXPERIMENTAL MODELING OF THREE-PHASE SLURRY-BUBBLE COLUMN REACTOR

    SciTech Connect (OSTI)

    Isaac K. Gamwo; Dimitri Gidaspow

    1999-09-01

    Considerable progress has been achieved in understanding three-phase reactors from the point of view of kinetic theory. In a paper in press for publication in Chemical Engineering Science (Wu and Gidaspow, 1999) we have obtained a complete numerical solution of bubble column reactors. In view of the complexity of the simulation a better understanding of the processes using simplified analytical solutions is required. Such analytical solutions are presented in the attached paper, Large Scale Oscillations or Gravity Waves in Risers and Bubbling Beds. This paper presents analytical solutions for bubbling frequencies and standing wave flow patterns. The flow patterns in operating slurry bubble column reactors are not optimum. They involve upflow in the center and downflow at the walls. It may be possible to control flow patterns by proper redistribution of heat exchangers in slurry bubble column reactors. We also believe that the catalyst size in operating slurry bubble column reactors is not optimum. To obtain an optimum size we are following up on the observation of George Cody of Exxon who reported a maximum granular temperature (random particle kinetic energy) for a particle size of 90 microns. The attached paper, Turbulence of Particles in a CFB and Slurry Bubble Columns Using Kinetic Theory, supports George Cody's observations. However, our explanation for the existence of the maximum in granular temperature differs from that proposed by George Cody. Further computer simulations and experiments involving measurements of granular temperature are needed to obtain a sound theoretical explanation for the possible existence of an optimum catalyst size.

  8. Modeling the impediment of methane ebullition bubbles by seasonal lake ice

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

    Greene, S.; Walter Anthony, K. M.; Archer, D.; Sepulveda-Jauregui, A.; Martinez-Cruz, K.

    2014-12-08

    Microbial methane (CH4) ebullition (bubbling) from anoxic lake sediments comprises a globally significant flux to the atmosphere, but ebullition bubbles in temperate and polar lakes can be trapped by winter ice cover and later released during spring thaw. This "ice-bubble storage" (IBS) constitutes a novel mode of CH4 emission. Before bubbles are encapsulated by downward-growing ice, some of their CH4 dissolves into the lake water, where it may be subject to oxidation. We present field characterization and a model of the annual CH4 cycle in Goldstream Lake, a thermokarst (thaw) lake in interior Alaska. We find that summertime ebullition dominatesmore » annual CH4 emissions to the atmosphere. Eighty percent of CH4 in bubbles trapped by ice dissolves into the lake water column in winter, and about half of that is oxidized. The ice growth rate and the magnitude of the CH4 ebullition flux are important controlling factors of bubble dissolution. Seven percent of annual ebullition CH4 is trapped as IBS and later emitted as ice melts. In a future warmer climate, there will likely be less seasonal ice cover, less IBS, less CH4 dissolution from trapped bubbles, and greater CH4 emissions from northern lakes.« less

  9. Dilatometric measurements of helium densities in bubbles arising from tritium decay in tantalum

    SciTech Connect (OSTI)

    Schober, T.; Lasser, R.; Golczewski, J.; Dieker, C.; Trinkaus, H.

    1985-06-01

    The swelling rates of the bulk tritides TaT/sub 0.42/ and TaT/sub 0.103/ were measured at room temperature using the technique of strain gauges. Such swelling is expected in tritides because of the decay of tritium to /sup 3/He and the subsequent precipitation of gas bubbles. Observations were made for up to 10 months. Almost-linear swelling was found in the first months for both tritides, indicative of a constant /sup 3/He density in the bubbles. The slopes of the linear parts of the expansion curves normalized to the T concentration were almost identical in the two cases considered. From this a /sup 3/He-to-Ta atom volume ratio, v/sub He//..cap omega..< or =0.52 +- 0.03 in the bubbles was derived, which is in good agreement with recent but less direct spectroscopic measurements of /sup 4/He densities in bubbles formed after room-temperature implantation into other metals. Corrections for the presence of self-interstitials and their clusters and due to the elastic relaxation of the bubbles were considered. Calculated bubble pressures were in the vicinity of 5 GPa, which is close to the expected threshold pressure for athermal bubble growth.

  10. Tracking the Elusive QOOH Radical

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

    Tracking the Elusive QOOH Radical Tracking the Elusive QOOH Radical Print Monday, 29 June 2015 00:00 Ignition chemistry involves a complex web of reactions. By studying the reaction products-looking at this web from its perimeter inward-researchers have gradually deduced the nature of the "reactive intermediate" molecules that must lie at the center. Decades of research worldwide have shown that hydroperoxyalkyl radicals-a class of reactive molecules denoted as "QOOH"-must be

  11. Effects of laminar separation bubbles and turbulent separation on airfoil stall

    SciTech Connect (OSTI)

    Dini, P.; Coiro, D.P.

    1997-12-31

    An existing two-dimensional, interactive, stall prediction program is extended by improving its laminar separation bubble model. The program now accounts correctly for the effects of the bubble on airfoil performance characteristics when it forms at the mid-chord and on the leading edge. Furthermore, the model can now predict bubble bursting on very sharp leading edges at high angles of attack. The details of the model are discussed in depth. Comparisons of the predicted stall and post-stall pressure distributions show excellent agreement with experimental measurements for several different airfoils at different Reynolds numbers.

  12. Fluctuations of permeation rate through an iron membrane induced by hydrogen bubbles

    SciTech Connect (OSTI)

    Amrani, Z.; Jerome, M.; Manolatos, P.; Wenger, F. ); Huet, F. )

    1994-08-01

    Using the electrochemical permeation technique, the authors have recorded fluctuations of the concentration of absorbed hydrogen in an Armco iron membrane during cathodic hydrogen charging in acidic solution. The fluctuations coincide quite closely with the dynamics of hydrogen bubbles at the cathode surface, which were followed both visually and by recording cathode-potential and ohmic-resistance fluctuations. The local flux of hydrogen into the iron membrane gradually decreased when there is an attached bubble growing and quickly increases when the bubble departs. An excellent correlation was found between the fluctuations of the concentration of absorbed hydrogen in the first layers of metal and the fluctuations of the cathode potential.

  13. Characterization of intergranular fission gas bubbles in U-Mo fuel.

    SciTech Connect (OSTI)

    Kim, Y. S.; Hofman, G.; Rest, J.; Shevlyakov, G. V.; Nuclear Engineering Division; SSCR RIAR

    2008-04-14

    This report can be divided into two parts: the first part, which is composed of sections 1, 2, and 3, is devoted to report the analyses of fission gas bubbles; the second part, which is in section 4, is allocated to describe the mechanistic model development. Swelling data of irradiated U-Mo alloy typically show that the kinetics of fission gas bubbles is composed of two different rates: lower initially and higher later. The transition corresponds to a burnup of {approx}0 at% U-235 (LEU) or a fission density of {approx}3 x 10{sup 21} fissions/cm{sup 3}. Scanning electron microscopy (SEM) shows that gas bubbles appear only on the grain boundaries in the pretransition regime. At intermediate burnup where the transition begins, gas bubbles are observed to spread into the intragranular regions. At high burnup, they are uniformly distributed throughout fuel. In highly irradiated U-Mo alloy fuel large-scale gas bubbles form on some fuel particle peripheries. In some cases, these bubbles appear to be interconnected and occupy the interface region between fuel and the aluminum matrix for dispersion fuel, and fuel and cladding for monolithic fuel, respectively. This is a potential performance limit for U-Mo alloy fuel. Microscopic characterization of the evolution of fission gas bubbles is necessary to understand the underlying phenomena of the macroscopic behavior of fission gas swelling that can lead to a counter measure to potential performance limit. The microscopic characterization data, particularly in the pre-transition regime, can also be used in developing a mechanistic model that predicts fission gas bubble behavior as a function of burnup and helps identify critical physical properties for the future tests. Analyses of grain and grain boundary morphology were performed. Optical micrographs and scanning electron micrographs of irradiated fuel from RERTR-1, 2, 3 and 5 tests were used. Micrographic comparisons between as-fabricated and as-irradiated fuel revealed

  14. Phase-field simulations of intragranular fission gas bubble evolution in UO2 under post-irradiation thermal annealing

    SciTech Connect (OSTI)

    Li, Yulan; Hu, Shenyang Y.; Montgomery, Robert O.; Gao, Fei; Sun, Xin

    2013-05-15

    Fission gas bubble is one of evolving microstructures, which affect thermal mechanical properties such as thermo-conductivity, gas release, volume swelling, and cracking, in operating nuclear fuels. Therefore, fundamental understanding of gas bubble evolution kinetics is essential to predict the thermodynamic property and performance changes of fuels. In this work, a generic phasefield model was developed to describe the evolution kinetics of intra-granular fission gas bubbles in UO2 fuels under post-irradiation thermal annealing conditions. Free energy functional and model parameters are evaluated from atomistic simulations and experiments. Critical nuclei size of the gas bubble and gas bubble evolution were simulated. A linear relationship between logarithmic bubble number density and logarithmic mean bubble diameter is predicted which is in a good agreement with experimental data.

  15. Robotic vehicle with multiple tracked mobility platforms

    DOE Patents [OSTI]

    Salton, Jonathan R. (Albuquerque, NM); Buttz, James H. (Albuquerque, NM); Garretson, Justin (Albuquerque, NM); Hayward, David R. (Wetmore, CO); Hobart, Clinton G. (Albuquerque, NM); Deuel, Jr., Jamieson K. (Albuquerque, NM)

    2012-07-24

    A robotic vehicle having two or more tracked mobility platforms that are mechanically linked together with a two-dimensional coupling, thereby forming a composite vehicle of increased mobility. The robotic vehicle is operative in hazardous environments and can be capable of semi-submersible operation. The robotic vehicle is capable of remote controlled operation via radio frequency and/or fiber optic communication link to a remote operator control unit. The tracks have a plurality of track-edge scallop cut-outs that allow the tracks to easily grab onto and roll across railroad tracks, especially when crossing the railroad tracks at an oblique angle.

  16. Initial Back-to-Back Fission Chamber Testing in ATRC

    SciTech Connect (OSTI)

    Benjamin Chase; Troy Unruh; Joy Rempe

    2014-06-01

    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.

  17. Inertial confinement fusion reaction chamber and power conversion system study

    SciTech Connect (OSTI)

    Maya, I.; Schultz, K.R.; Battaglia, J.M.; Buksa, J.J.; Creedson, R.L.; Erlandson, O.D.; Levine, H.E.; Roelant, D.F.; Sanchez, H.W.; Schrader, S.A.

    1984-09-01

    GA Technologies has developed a conceptual ICF reactor system based on the Cascade rotating-bed reaction chamber concept. Unique features of the system design include the use of low activation SiC in a reaction chamber constructed of box-shaped tiles held together in compression by prestressing tendons to the vacuum chamber. Circulating Li/sub 2/O granules serve as the tritium breeding and energy transport material, cascading down the sides of the reaction chamber to the power conversion system. The total tritium inventory of the system is 6 kg; tritium recovery is accomplished directly from the granules via the vacuum system. A system for centrifugal throw transport of the hot Li/sub 2/O granules from the reaction chamber to the power conversion system has been developed. A number of issues were evaluated during the course of this study. These include the response of first-layer granules to the intense microexplosion surface heat flux, cost effective fabrication of Li/sub 2/O granules, tritium inventory and recovery issues, the thermodynamics of solids-flow options, vacuum versus helium-medium heat transfer, and the tradeoffs of capital cost versus efficiency for alternate heat exchange and power conversion system option. The resultant design options appear to be economically competitive, safe, and environmentally attractive.

  18. Atmosphere contamination following repainting of a human hyperbaric chamber complex

    SciTech Connect (OSTI)

    Lillo, R.S.; Morris, J.W.; Caldwell, J.M.; Balk, D.M.; Flynn, E.T. )

    1990-09-01

    The Naval Medical Research Institute currently conducts hyperbaric research in a Man-Rated Chamber Complex (MRCC) originally installed in 1977. Significant engineering alterations to the MRCC and rusting of some of its interior sections necessitated repainting, which was completed in 1988. Great care was taken in selecting an appropriate paint (polyamide epoxy) and in ensuring correct application and curing procedures. Only very low levels of hydrocarbons were found in the MRCC atmosphere before initial pressurization after painting and curing. After pressurization, however, significant chemical contamination was found. The primary contaminants were aromatic hydrocarbons: xylenes (which were a major component of both the primer and topcoat paint) and ethyl benzene. The role that pressure played in stimulating off-gassing from the paint is not clear; the off-gassing rate was observed to be similar over a large range in chamber pressures from 1.6 to 31.0 atm abs. Scrubbing the chamber atmosphere with the chemical absorbent Purafil was effective in removing the contaminants. Contamination has been observed to slowly decline with chamber use and is expected to continue to improve with time. However, this contamination experience emphasizes the need for a high precision gas analysis program at any diving facility to ensure the safety of the breathing gas and chamber atmosphere.

  19. Geek-Up[6.24.11]: The End of Our Solar System is Bubbly

    Office of Energy Efficiency and Renewable Energy (EERE)

    The Cray XT4 supercomputer at the Lawrence Berkeley National Laboratory’s National Energy Research Scientific Computing Center (NERSC) is helping to explain the froth of apparent "bubbles."

  20. The PEP-II Lower Pressure HER Vacuum Chamber

    SciTech Connect (OSTI)

    DeBarger, S.; Metcalfe, S.; Seeman, J.; Sullivan, M.; Wienands, U.; Wright, D.; /SLAC

    2006-03-13

    This new vacuum chamber has been installed from 12 to 21 meters upstream of the BaBar detector in the PEP-II High Energy Ring (HER) to reduce lost particle backgrounds. The backgrounds from HER now dominate the backgrounds in the BaBar detector and the present vacuum pressure is 1 x 10{sup -9} Torr. The new chamber will increase the pumping significantly by adding 18 x 2000 l/s titanium sublimation pumps to the existing 5 x 440 l/s ion pumps, and is expected to reduce the pressure by about a factor of five. Features of the chamber include improved water cooling, improved vacuum conductance through copper RF screens featuring over 15,000 small square holes and the ability to sublimate titanium while the beam is still on.

  1. Extreme-UV lithography vacuum chamber zone seal

    DOE Patents [OSTI]

    Haney, Steven J.; Herron, Donald Joe; Klebanoff, Leonard E.; Replogle, William C.

    2003-04-15

    Control of particle contamination on the reticle and carbon contamination of optical surfaces in photolithography systems can be achieved by the establishment of multiple pressure zones in the photolithography systems. The different zones will enclose the reticle, projection optics, wafer, and other components of system. The system includes a vacuum apparatus that includes: a housing defining a vacuum chamber; one or more metrology trays situated within the vacuum chamber each of which is supported by at least one support member, wherein the tray separates the vacuum chamber into a various compartments that are maintained at different pressures; and conductance seal devices for adjoining the perimeter of each tray to an inner surface of the housing wherein the tray is decoupled from vibrations emanating from the inner surface of the housing.

  2. Extreme-UV lithography vacuum chamber zone seal

    DOE Patents [OSTI]

    Haney, Steven J.; Herron, Donald Joe; Klebanoff, Leonard E.; Replogle, William C.

    2001-01-01

    Control of particle contamination on the reticle and carbon contamination of optical surfaces in photolithography systems can be achieved by the establishment of multiple pressure zones in the photolithography systems. The different zones will enclose the reticle, projection optics, wafer, and other components of system. The system includes a vacuum apparatus that includes: a housing defining a vacuum chamber; one or more metrology trays situated within the vacuum chamber each of which is supported by at least one support member, wherein the tray separates the vacuum chamber into a various compartments that are maintained at different pressures; and conductance seal devices for adjoining the perimeter of each tray to an inner surface of the housing wherein the tray is decoupled from vibrations emanating from the inner surface of the housing.

  3. Extreme-UV lithography vacuum chamber zone seal

    DOE Patents [OSTI]

    Haney, Steven J.; Herron, Donald Joe; Klebanoff, Leonard E.; Replogle, William C.

    2003-04-08

    Control of particle contamination on the reticle and carbon contamination of optical surfaces in photolithography systems can be achieved by the establishment of multiple pressure zones in the photolithography systems. The different zones will enclose the reticle, projection optics, wafer, and other components of system. The system includes a vacuum apparatus that includes: a housing defining a vacuum chamber; one or more metrology trays situated within the vacuum chamber each of which is supported by at least one support member, wherein the tray separates the vacuum chamber into a various compartments that are maintained at different pressures; and conductance seal devices for adjoining the perimeter of each tray to an inner surface of the housing wherein the tray is decoupled from vibrations emanating from the inner surface of the housing.

  4. MESO-SCALE MODELING OF THE INFLUENCE OF INTERGRANULAR GAS BUBBLES ON EFFECTIVE THERMAL CONDUCTIVITY

    SciTech Connect (OSTI)

    Paul C. Millett; Michael Tonks

    2011-06-01

    Using a mesoscale modeling approach, we have investigated how intergranular fission gas bubbles, as observed in high-burnup nuclear fuel, modify the effective thermal conductivity in a polycrystalline material. The calculations reveal that intergranular porosity has a significantly higher resistance to heat transfer compared to randomly-distributed porosity. A model is developed to describe this conductivity reduction that considers an effective grain boundary Kapitza resistance as a function of the fractional coverage of grain boundaries by bubbles.

  5. Bubbles Help Break Energy Storage Record for Lithium Air-Batteries

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

    Bubbles Help Break Energy Storage Record for Lithium Air-Batteries Bubbles Help Break Energy Storage Record for Lithium Air-Batteries Foam-base graphene keeps oxygen flowing in batteries that holds promise for electric vehicles January 25, 2012 Linda Vu, lvu@lbl.gov, +1 510 495 2402 Using a new approach, the team built a graphene membrane for use in lithium-air batteries, which could, one day, replace conventional batteries in electric vehicles. Resembling coral, this porous graphene material

  6. Operation of drift chambers with helium based mixtures

    SciTech Connect (OSTI)

    Sharma, A. ); Sauli, F. )

    1994-08-01

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

  7. Fuel subassembly leak test chamber for a nuclear reactor

    DOE Patents [OSTI]

    Divona, Charles J.

    1978-04-04

    A container with a valve at one end is inserted into a nuclear reactor coolant pool. Once in the pool, the valve is opened by a mechanical linkage. An individual fuel subassembly is lifted into the container by a gripper; the valve is then closed providing an isolated chamber for the subassembly. A vacuum is drawn on the chamber to encourage gaseous fission product leakage through any defects in the cladding of the fuel rods comprising the subassembly; this leakage may be detected by instrumentation, and the need for replacement of the assembly ascertained.

  8. Employee Concerns Tracking System, PIA, Bechtel Jacobs Company...

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

    Concerns Tracking System, PIA, Bechtel Jacobs Company, LLC Employee Concerns Tracking System, PIA, Bechtel Jacobs Company, LLC Employee Concerns Tracking System, PIA, Bechtel ...

  9. Experimental investigation of bubbling in particle beds with high solid holdup

    SciTech Connect (OSTI)

    Cheng, Songbai; Hirahara, Daisuke; Tanaka, Youhei; Gondai, Yoji; Zhang, Bin; Matsumoto, Tatsuya; Morita, Koji; Fukuda, Kenji; Yamano, Hidemasa; Suzuki, Tohru; Tobita, Yoshiharu

    2011-02-15

    A series of experiments on bubbling behavior in particle beds was performed to clarify three-phase flow dynamics in debris beds formed after core-disruptive accident (CDA) in sodium-cooled fast breeder reactors (FBRs). Although in the past, several experiments have been performed in packed beds to investigate flow patterns, most of these were under comparatively higher gas flow rate, which may be not expected during an early sodium boiling period in debris beds. The current experiments were conducted under two dimensional (2D) and three dimensional (3D) conditions separately, in which water was used as liquid phase, and bubbles were generated by injecting nitrogen gas from the bottom of the viewing tank. Various particle-bed parameters were varied, including particle-bed height (from 30 mm to 200 mm), particle diameter (from 0.4 mm to 6 mm) and particle type (beads made of acrylic, glass, alumina and zirconia). Under these experimental conditions, three kinds of bubbling behavior were observed for the first time using digital image analysis methods that were further verified by quantitative detailed analysis of bubbling properties including surface bubbling frequency and surface bubble size under both 2D and 3D conditions. This investigation, which hopefully provides fundamental data for a better understanding and an improved estimation of CDAs in FBRs, is expected to benefit future analysis and verification of computer models developed in advanced fast reactor safety analysis codes. (author)

  10. Track 5: Integration of Safety Into Design

    Broader source: Energy.gov [DOE]

    ISM Workshop Presentations Knoxville Convention Center, Knoxville, TN August 2009 Track 5: Integration of Safety Into Design